WorldWideScience

Sample records for calcination

  1. Calcine production and management

    International Nuclear Information System (INIS)

    Dickey, B.R.; Hogg, G.W.; Berreth, J.R.

    1979-01-01

    The process technology related to calcination of power reactor wastes is summarized. The primary calcination processes developed are spray calcination, fluidized-bed calcination, and rotary kiln calcination. Calcines from the spray calciner and rotary kiln are fed directly to a glassification process. The fluidized-bed product can either be fed to a waste form conversion process or stored. The major process steps for calcinations are feed preparation, calcination and product handling, and off-gas cleanup. Feed systems for the three processes are basically similar. Gravity flow and pump pressurized systems have been used successfully. The major problems are fatigue failure of feed valve bellows, plugging by undissolved solids, and calibration of flowmeters. Process heat input is by electrical resistance heating for the spray and rotary kiln calciners and in-bed combustion or in-bed heat exchange for the fluidized-bed system. Low-melting solids which can cause scaling or solids agglomeration in any of the processes is a major calcination problem; however, feed blending, process operating conditions, and equipment design have successfully controlled solids agglomeration. Primary off-gas cleanup devices for particulates are cyclones, sintered metal filters, venturi scrubbers, and HEPA filters. Scrubbers, condensers, and solid adsorbents are used successfully for volatile ruthenium removal. The years of pilot-plant and plant-scale calcination testing and operation of the three systems have shown that reactor wastes can be calcined safely and practically. 11 figures, 2 tables

  2. Uranium dioxide calcining apparatus

    International Nuclear Information System (INIS)

    Cole, E.A.; Peterson, R.S.

    1978-01-01

    This invention relates to an improved continuous calcining apparatus for consistently and controllably producing from calcinable reactive solid compounds of uranium, such as ammonium diuranate, uranium dioxide (UO 2 ) having an oxygen to uranium ratio of less than 2.2. The apparatus comprises means at the outlet end of a calciner kiln for receiving hot UO 2 , means for cooling the UO 2 to a temperature of below 100 deg C and conveying the cooled UO 2 to storage or to subsequent UO 2 processing apparatus where it finally comes into contact with air, the means for receiving cooling and conveying being sealed to the outlet end of the calciner and being maintained full of UO 2 and so operable as to exclude atmospheric oxygen from coming into contact with any UO 2 which is at elevated temperatures where it would readily oxidize, without the use of extra hydrogen gas in said means. (author)

  3. Method for calcining radioactive wastes

    International Nuclear Information System (INIS)

    Bjorklund, W.J.; McElroy, J.L.; Mendel, J.E.

    1979-01-01

    A method for the preparation of radioactive wastes in a low leachability form involves calcining the radioactive waste on a fluidized bed of glass frit, removing the calcined waste to melter to form a homogeneous melt of the glass and the calcined waste, and then solidifying the melt to encapsulate the radioactive calcine in a glass matrix

  4. Fluidized bed calciner

    International Nuclear Information System (INIS)

    Sheely, W.F.

    1986-01-01

    A unique way to convert radioactive scrap into useful nuclear fuel products was developed for the Department of Energy at Hanford. An advanced, fluidized bed calciner is used to convert metallic nitrate scrap or waste solutions into benign, solid and gaseous products. There are broad potential applications of this concept beyond those in the nuclear industry

  5. Spray calcination of nuclear wastes

    International Nuclear Information System (INIS)

    Bonner, W.F.; Blair, H.T.; Romero, L.S.

    1976-01-01

    The spray calciner is a relatively simple machine; operation is simple and is easily automated. Startup and shutdown can be performed in less than an hour. A wide variety of waste compositions and concentrations can be calcined under easily maintainable conditions. Spray calcination of all commercial fuel reprocessor high-level liquid wastes and mixed high and intermediate-level wastes have been demonstrated. Wastes have been calcined containing over 2M sodium. Thus waste generated during plant startup and shutdown can be blended with normal waste and calcined. Spray calcination of ILLW has also been demonstrated. A remotely replaceable atomizing nozzle has been developed for use in plant scale equipment. The 6 mm (0.25 inch) orifice and ceramic tip offer freedom from plugging and erosion thus nozzle replacement should be required only after several months operation. Calciner capacity of over 75 l/h (20 gal/h) has been demonstrated in pilot scale equipment. Sintered stainless steel filters are effective in deentraining over 99.9 percent of the solids that result from calcining the feedstock. Since such a small amount of radionuclides escape the calciner the volume of recycle required from the effluent treatment system is very small. The noncondensable off-gas volume is also low, less than 0.5 m 3 /min (15 scfm) for a liquid feedrate of 75 l/hr (20 gal/hr). Calcine holdup in the calciner is less than 1 kg, thus the liquid feedrate is directly relatable to calcine flowrate. The calcine produced is very fine and reactive. Successful remote operation and maintenance of a heated wall spray calciner has been demonstrated while processing actual high-level waste. During these operations radionuclide volatilization from the calciner was acceptably low. 8 figures

  6. Calcination/dissolution residue treatment

    International Nuclear Information System (INIS)

    Knight, R.C.; Creed, R.F.; Patello, G.K.; Hollenberg, G.W.; Buehler, M.F.; O'Rourke, S.M.; Visnapuu, A.; McLaughlin, D.F.

    1994-09-01

    Currently, high-level wastes are stored underground in steel-lined tanks at the Hanford site. Current plans call for the chemical pretreatment of these wastes before their immobilization in stable glass waste forms. One candidate pretreatment approach, calcination/dissolution, performs an alkaline fusion of the waste and creates a high-level/low-level partition based on the aqueous solubilities of the components of the product calcine. Literature and laboratory studies were conducted with the goal of finding a residue treatment technology that would decrease the quantity of high-level waste glass required following calcination/dissolution waste processing. Four elements, Fe, Ni, Bi, and U, postulated to be present in the high-level residue fraction were identified as being key to the quantity of high-level glass formed. Laboratory tests of the candidate technologies with simulant high-level residues showed reductive roasting followed by carbonyl volatilization to be successful in removing Fe, Ni, and Bi. Subsequent bench-scale tests on residues from calcination/dissolution processing of genuine Hanford Site tank waste showed Fe was separated with radioelement decontamination factors of 70 to 1,000 times with respect to total alpha activity. Thermodynamic analyses of the calcination of five typical Hanford Site tank waste compositions also were performed. The analyses showed sodium hydroxide to be the sole molten component in the waste calcine and emphasized the requirement for waste blending if fluid calcines are to be achieved. Other calcine phases identified in the thermodynamic analysis indicate the significant thermal reconstitution accomplished in calcination

  7. Alternative calcination development status report

    International Nuclear Information System (INIS)

    Boardman, R.D.

    1997-12-01

    The Programmatic Spent Nuclear Fuel and (INEEL) Environmental Restoration and Waste Management Programs Environmental Impact Statement Record of Decision, dated June 1, 1995, specifies that high-level waste stored in the underground tanks at the ICPP continue to be calcined while other options to treat the waste are studied. Therefore, the High-Level Waste Program has funded a program to develop new flowsheets to increase the liquid waste processing rate. Simultaneously, a radionuclide separation process, as well as other options, are also being developed, which will be compared to the calcination treatment option. Two alternatives emerged as viable candidates; (1) elevated temperature calcination (also referred to as high temperature calcination), and (2) sugar-additive calcination. Both alternatives were determined to be viable through testing performed in a lab-scale calcination mockup. Subsequently, 10-cm Calciner Pilot Plant scoping tests were successfully completed for both flowsheets. The results were compared to the standard 500 C, high-ANN flow sheet (baseline flowsheet). The product and effluent streams were characterized to help elucidate the process chemistry and to investigate potential environmental permitting issues. Several supplementary tests were conducted to gain a better understanding of fine-particles generation, calcine hydration, scrub foaming, feed makeup procedures, sugar/organic elimination, and safety-related issues. Many of the experiments are only considered to be scoping tests, and follow-up experiments will be required to establish a more definitive understanding of the flowsheets. However, the combined results support the general conclusion that flowsheet improvements for the NWCF are technically viable

  8. New Waste Calciner High Temperature Operation

    International Nuclear Information System (INIS)

    Swenson, M.C.

    2000-01-01

    A new Calciner flowsheet has been developed to process the sodium-bearing waste (SBW) in the INTEC Tank Farm. The new flowsheet increases the normal Calciner operating temperature from 500 C to 600 C. At the elevated temperature, sodium in the waste forms stable aluminates, instead of nitrates that melt at calcining temperatures. From March through May 2000, the new high-temperature flowsheet was tested in the New Waste Calcining Facility (NWCF) Calciner. Specific test criteria for various Calciner systems (feed, fuel, quench, off-gas, etc.) were established to evaluate the long-term operability of the high-temperature flowsheet. This report compares in detail the Calciner process data with the test criteria. The Calciner systems met or exceeded all test criteria. The new flowsheet is a visible, long-term method of calcining SBW. Implementation of the flowsheet will significantly increase the calcining rate of SBW and reduce the amount of calcine produced by reducing the amount of chemical additives to the Calciner. This will help meet the future waste processing milestones and regulatory needs such as emptying the Tank Farm

  9. Summary of Waste Calcination at INTEC

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, Barry Henry; Newby, Bill Joe

    2000-10-01

    Fluidized-bed calcination at the Idaho Nuclear Technologies and Engineering Center (INTEC, formally called the Idaho Chemical Processing Plant) has been used to solidify acidic metal nitrate fuel reprocessing and incidental wastes wastes since 1961. A summary of waste calcination in full-scale and pilot plant calciners has been compiled for future reference. It contains feed compositions and operating conditions for all the processing campaigns for the original Waste Calcining Facility (WCF), the New Waste Calcining Facility (NWCF) started up in 1982, and numerous small scale pilot plant tests for various feed types. This summary provides a historical record of calcination at INTEC, and will be useful for evaluating calcinability of future wastes.

  10. Calcination under negative atmosphere for SYNROC preparation

    International Nuclear Information System (INIS)

    Ambashta, R.D.; Wattal, P.K.; Govindankutty, K.V.

    2006-01-01

    SYNROC-C is a ceramic waste formulation designed to immobilise reprocessing waste from fast breeder reactor. This formulation is capable of incorporating noble metals, other fission products, corrosion products and activation products in its multiphase assemblage. Calcination is an important step of SYNROC preparation for decomposition of nitrates of the radioactive waste and conversion to oxide precursors. This paper presents a comparison between properties of calcine prepared under different calcination procedures to obtain product suitable for compaction

  11. Experimental and modeling study of flash calcination of kaolinite rich clay particles in a gas suspension calciner

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2015-01-01

    gas suspension calciner, with the aim to derive useful guidelines on smart calcination for obtaining products of the best pozzolanic properties. Calcination tests are performed in the calciner under six different operation conditions. The raw feed and the calcined clay samples are all characterized...

  12. XANES analysis of dried and calcined bones

    International Nuclear Information System (INIS)

    Rajendran, Jayapradhi; Gialanella, Stefano; Aswath, Pranesh B.

    2013-01-01

    The structure of dried and calcined bones from chicken, bovine, deer, pig, sheep and chamois was examined using X-ray Absorption Near Edge Structure (XANES) spectroscopy. The oxygen K-edge absorption edge indicates that the surface of dried bone has a larger proportion of carbonate than the interior that is made up of phosphates. The phosphorus L and K edge clearly indicate that pyrophosphates, α-tricalcium phosphate (α-TCP) and hydrogen phosphates of Ca do not exist in either the dried bone or calcined bone and phosphorus exists as either β-tricalcium phosphate (β-TCP) or hydroxyapatite, both in the dried and calcined conditions. The Ca K-edge analysis indicates that β-TCP is the likely form of phosphate in both the dried and calcined conditions. - Highlights: • For the first time bones of five different species of vertebrates have been compared in both the dried and calcined states. • O, P and Ca edges detail the local coordination of these atoms in dried and calcined bone. • O K-edge shows that the surface of bone has more CO 3 while the interior has more PO 4 . • P and Ca edges eliminate the presence of pyrophosphates and confirmed the presence of HA and β-TCP. • The stability of these phosphates on calcination has been examined using XANES

  13. XANES analysis of dried and calcined bones

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, Jayapradhi [Materials Science and Engineering Department, University of Texas at Arlington (United States); Gialanella, Stefano [Materials Science and Industrial Technology Department, University of Trento (Italy); Aswath, Pranesh B., E-mail: aswath@uta.edu [Materials Science and Engineering Department, University of Texas at Arlington (United States)

    2013-10-15

    The structure of dried and calcined bones from chicken, bovine, deer, pig, sheep and chamois was examined using X-ray Absorption Near Edge Structure (XANES) spectroscopy. The oxygen K-edge absorption edge indicates that the surface of dried bone has a larger proportion of carbonate than the interior that is made up of phosphates. The phosphorus L and K edge clearly indicate that pyrophosphates, α-tricalcium phosphate (α-TCP) and hydrogen phosphates of Ca do not exist in either the dried bone or calcined bone and phosphorus exists as either β-tricalcium phosphate (β-TCP) or hydroxyapatite, both in the dried and calcined conditions. The Ca K-edge analysis indicates that β-TCP is the likely form of phosphate in both the dried and calcined conditions. - Highlights: • For the first time bones of five different species of vertebrates have been compared in both the dried and calcined states. • O, P and Ca edges detail the local coordination of these atoms in dried and calcined bone. • O K-edge shows that the surface of bone has more CO{sub 3} while the interior has more PO{sub 4}. • P and Ca edges eliminate the presence of pyrophosphates and confirmed the presence of HA and β-TCP. • The stability of these phosphates on calcination has been examined using XANES.

  14. Calcined solids storage facility closure study

    International Nuclear Information System (INIS)

    Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C.

    1998-02-01

    The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a open-quotes Settlement Agreementclose quotes (or open-quotes Batt Agreementclose quotes) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed

  15. Calcined solids storage facility closure study

    Energy Technology Data Exchange (ETDEWEB)

    Dahlmeir, M.M.; Tuott, L.C.; Spaulding, B.C. [and others

    1998-02-01

    The disposal of radioactive wastes now stored at the Idaho National Engineering and Environmental Laboratory is currently mandated under a {open_quotes}Settlement Agreement{close_quotes} (or {open_quotes}Batt Agreement{close_quotes}) between the Department of Energy and the State of Idaho. Under this agreement, all high-level waste must be treated as necessary to meet the disposal criteria and disposed of or made road ready to ship from the INEEL by 2035. In order to comply with this agreement, all calcined waste produced in the New Waste Calcining Facility and stored in the Calcined Solids Facility must be treated and disposed of by 2035. Several treatment options for the calcined waste have been studied in support of the High-Level Waste Environmental Impact Statement. Two treatment methods studied, referred to as the TRU Waste Separations Options, involve the separation of the high-level waste (calcine) into TRU waste and low-level waste (Class A or Class C). Following treatment, the TRU waste would be sent to the Waste Isolation Pilot Plant (WIPP) for final storage. It has been proposed that the low-level waste be disposed of in the Tank Farm Facility and/or the Calcined Solids Storage Facility following Resource Conservation and Recovery Act closure. In order to use the seven Bin Sets making up the Calcined Solids Storage Facility as a low-level waste landfill, the facility must first be closed to Resource Conservation and Recovery Act (RCRA) standards. This study identifies and discusses two basic methods available to close the Calcined Solids Storage Facility under the RCRA - Risk-Based Clean Closure and Closure to Landfill Standards. In addition to the closure methods, the regulatory requirements and issues associated with turning the Calcined Solids Storage Facility into an NRC low-level waste landfill or filling the bin voids with clean grout are discussed.

  16. New Waste Calcining Facility (NWCF) Waste Streams

    International Nuclear Information System (INIS)

    K. E. Archibald

    1999-01-01

    This report addresses the issues of conducting debris treatment in the New Waste Calcine Facility (NWCF) decontamination area and the methods currently being used to decontaminate material at the NWCF

  17. Activity and structure of calcined coal gangue

    Energy Technology Data Exchange (ETDEWEB)

    Gong Chenchen; Li Dongxu; Wang Xiaojun; Li Zongjin [Nanjing University of Technology, Nanjing (China). College of Materials Science and Engineering

    2007-12-15

    Coal gangue was activated by means of calcination in seven temperature ranges. Systematic research was made about activation mechanism and structural evolution. The glycerin-ethanol method, SEM, MIP and XRD were used to determine the variation of structure and activation of coal gangue during calcination. The experimental results show that because of heat treatment in the range of calcination temperatures, mineral composition and microstructure of coal gangue are changed. In addition, its activity is improved. The amount of lime absorbed by the sample calcined at 700{sup o}C is 2-4 times that by uncalcined coal gangue in the course of hydration. When NaOH is added to coal gangue-lime system, the hydration reaction rate of the system is increased and the microstructure of hydrating samples of coal gangue is improved.

  18. Uranium dioxide calcining apparatus and method

    International Nuclear Information System (INIS)

    Cole, E.A.; Peterson, R.S.

    1978-01-01

    This invention relates to an improved continuous calcining apparatus for consistently and controllably producing from calcinable reactive solid compounds of uranium, such as ammonium diuranate, uranium dioxide (UO 2 ) having an oxygen to uranium ratio of less than 2.2. The apparatus comprises means at the outlet end of a calciner kiln for receiving hot UO 2 , means for cooling the UO 2 to a temperature of below 100 0 C and conveying the cooled UO 2 to storage or to subsequent UO 2 processing apparatus where it finally comes into contact with air, the means for receiving, cooling and conveying being sealed to the outlet end of the calciner and being maintained full of UO 2 and so operable as to exclude atmospheric oxygen from coming into contact with any UO 2 which is at elevated temperatures where it would readily oxidize, without the use of extra hydrogen gas in said means

  19. Bin Set 1 Calcine Retrieval Feasibility Study

    Energy Technology Data Exchange (ETDEWEB)

    R. D. Adams; S. M. Berry; K. J. Galloway; T. A. Langenwalter; D. A. Lopez; C. M. Noakes; H. K. Peterson; M. I. Pope; R. J. Turk

    1999-10-01

    At the Department of Energy's Idaho Nuclear Technology and Engineering Center, as an interim waste management measure, both mixed high-level liquid waste and sodium bearing waste have been solidified by a calculation process and are stored in the Calcine Solids Storage Facilities. This calcined product will eventually be treated to allow final disposal in a national geologic repository. The Calcine Solids Storage Facilities comprise seven ''bit sets.'' Bin Set 1, the first to be constructed, was completed in 1959, and has been in service since 1963. It is the only bin set that does not meet current safe-shutdown earthquake seismic criteria. In addition, it is the only bin set that lacks built-in features to aid in calcine retrieval. One option to alleviate the seismic compliance issue is to transport the calcine from Bin Set 1 to another bin set which has the required capacity and which is seismically qualified. This report studies the feasibility of retrieving the calcine from Bi n Set 1 and transporting it into Bin Set 6 which is located approximately 650 feet away. Because Bin Set 1 was not designed for calcine retrieval, and because of the high radiation levels and potential contamination spread from the calcined material, this is a challenging engineering task. This report presents preconceptual design studies for remotely-operated, low-density, pneumatic vacuum retrieval and transport systems and equipment that are based on past work performed by the Raytheon Engineers and Constructors architectural engineering firm. The designs presented are considered feasible; however, future development work will be needed in several areas during the subsequent conceptual design phase.

  20. Bin Set 1 Calcine Retrieval Feasibility Study

    International Nuclear Information System (INIS)

    Adams, R.D.; Berry, S.M.; Galloway, K.J.; Langenwalter, T.A.; Lopez, D.A.; Noakes, C.M.; Peterson, H.K.; Pope, M.I.; Turk, R.J.

    1999-01-01

    At the Department of Energy's Idaho Nuclear Technology and Engineering Center, as an interim waste management measure, both mixed high-level liquid waste and sodium bearing waste have been solidified by a calculation process and are stored in the Calcine Solids Storage Facilities. This calcined product will eventually be treated to allow final disposal in a national geologic repository. The Calcine Solids Storage Facilities comprise seven ''bit sets.'' Bin Set 1, the first to be constructed, was completed in 1959, and has been in service since 1963. It is the only bin set that does not meet current safe-shutdown earthquake seismic criteria. In addition, it is the only bin set that lacks built-in features to aid in calcine retrieval. One option to alleviate the seismic compliance issue is to transport the calcine from Bin Set 1 to another bin set which has the required capacity and which is seismically qualified. This report studies the feasibility of retrieving the calcine from Bi n Set 1 and transporting it into Bin Set 6 which is located approximately 650 feet away. Because Bin Set 1 was not designed for calcine retrieval, and because of the high radiation levels and potential contamination spread from the calcined material, this is a challenging engineering task. This report presents preconceptual design studies for remotely-operated, low-density, pneumatic vacuum retrieval and transport systems and equipment that are based on past work performed by the Raytheon Engineers and Constructors architectural engineering firm. The designs presented are considered feasible; however, future development work will be needed in several areas during the subsequent conceptual design phase

  1. Properties of radioactive calcine retrieved from the second calcined solids storage facility at ICPP

    International Nuclear Information System (INIS)

    Staples, B.A.; Pomiak, G.S.; Wade, E.L.

    1979-03-01

    The chemical and physical properties of radioactive alumina and zirconia calcine samples retrieved from the storage bins at ICPP were measured. Chemical properties measured include chemical composition, crystalline structure, and radiochemical composition. The physical properties measured and reported include density, size distribution, relative attrition, solubility in 8 M HNO 3 , thermal stability, and flow characteristics. The chemical and physical properties of the retrieved calcine after the 10 to 12 years of storage are very similar to freshly prepared simulated calcine

  2. [Infrared spectral analysis for calcined borax].

    Science.gov (United States)

    Zhao, Cui; Ren, Li-Li; Wang, Dong; Zhou, Ping; Zhang, Qian; Wang, Bo-Tao

    2011-08-01

    To valuate the quality of calcined borax which is sold in the market, 18 samples of calcined borax were studied using the Fourier transform infrared, and samples with different water content were selected and analyzed. Then, the results of analysis were used to evaluate the quality of calcined borax. Results show that the infrared spectra of calcined borax include OH vibration, BO3(-3) vibration and BO4(5-) vibration absorption bands. The position and width of OH vibration absorption band depend on the level of water content, and the more the water content, the wider the absorption band. The number of BO3(3-) vibration and BO4(5-) vibration bands also depend on the level of water content, and the more the water content, and the stronger the hydrogen bond and the lower the symmetry of B atoms, the more the number of infrared absorption peaks. It was concluded that because the quality of calcined borax has direct correlation with water content, the infrared spectroscopy is an express and objective approach to quality analysis and evaluation of calcined borax.

  3. Experimental results: Pilot plant calcine dissolution and liquid feed stability

    International Nuclear Information System (INIS)

    Herbst, R.S.; Fryer, D.S.; Brewer, K.N.; Johnson, C.K.; Todd, T.A.

    1995-02-01

    The dissolution of simulated Idaho Chemical Processing Plant pilot plant calcines, containing none of the radioactive actinides, lanthanides or fission products, was examined to evaluate the solubility of calcine matrix materials in acidic media. This study was a necessary precursor to dissolution and optimization experiments with actual radionuclide-containing calcines. The importance of temperature, nitric acid concentration, ratio of acid volume to calcine mass, and time on the amount, as a weight percentage of calcine dissolved, was evaluated. These parameters were studied for several representative pilot plant calcine types: (1) Run No. 74 Zirconia calcine; (2) Run No. 17 Zirconia/Sodium calcine; (3) Run No. 64 Zirconia/Sodium calcine; (3) Run No. 1027 Alumina calcine; and (4) Run No. 20 Alumina/Zirconia/Sodium calcine. Statistically designed experiments with the different pilot plant calcines indicated the effect of the studied process variables on the amount of calcine dissolved decreases in the order: Acid/Calcine Ratio > Temperature > HNO 3 Concentration > Dissolution Time. The following conditions are suitable to achieve greater than 90 wt. % dissolution of most Zr, Al, or Na blend calcines: (1) Maximum nitric acid concentration of 5M; (2) Minimum acid/calcine ratio of 10 mL acid/1 gram calcine; (3) Minimum dissolution temperature of 90 degrees C; and (4) Minimum dissolution time of 30 minutes. The formation of calcium sulphate (CaSO 4 ) precipitates was observed in certain dissolved calcine solutions during the dissolution experiments. Consequently, a study was initiated to evaluate if and under what conditions the resulting dissolved calcine solutions would be unstable with regards to precipitate formation. The results indicate that precipitate formation in the calcine solutions prepared under the above proposed dissolution conditions are not anticipated

  4. Recovery of gold and uranium from calcines

    Energy Technology Data Exchange (ETDEWEB)

    Livesey-Goldblatt, E.

    1981-10-06

    The invention concerns the recovery of non-ferrous metals, such as gold, uranium or the like from iron oxide containing calcines which have the non-ferrous metal present in solid solution and/or encapsulated within the iron oxide. The calcine is reacted, while stirring vigorously, with sulphuric acid or another strong inorganic acid to cause the iron to form the ferric salt. The material obtained is mixed with water and the liquid and solid phases are separated from each other. The non-ferrous metal is then obtained from at least one of these phases by leaching, or the like.

  5. 1st International Conference on Calcined Clays for Sustainable Concrete

    CERN Document Server

    Favier, Aurélie

    2015-01-01

    This volume focuses on research and practical issues linked to Calcined Clays for Sustainable Concrete. The main subjects are geology of clays, hydration and performance of blended systems with calcined clays, alkali activated binders, economic and environmental impacts of the use of calcined clays in cement based materials. Topics addressed in this book include the influence of processing on reactivity of calcined clays, influence of clay mineralogy on reactivity, geology of clay deposits, Portland-calcined clay systems, hydration, durability, performance, Portland-calcined clay-limestone systems, hydration, durability, performance, calcined clay-alkali systems, life cycle analysis, economics and environmental impact of use of calcined clays in cement and concrete, and field applications. This book compiles the different contributions of the 1st International Conference on Calcined Clays for Sustainable Concrete, which took place in Lausanne, Switzerland, June, 23-25, 2015.The papers present the latest  res...

  6. Remotely replaceable fuel and feed nozzles for the new waste calcining facility calciner vessel

    International Nuclear Information System (INIS)

    Fletcher, R.D.; Carter, J.A.; May, K.W.

    1978-01-01

    The development and testing of remotely replaceable fuel and feed nozzles for calcination of liquid radioactive wastes in the calciner vessel of the New Waste Calcining Facility being built at the Idaho National Engineering Laboratory is described. A complete fuel nozzle assembly was fabricated and tested at the Remote Maintenance Development Facility to evolve design refinements, identify required support equipment, and develop handling techniques. The design also provided for remote replacement of the nozzle support carriage and adjacent feed and fuel pipe loops using two pairs of master-slave manipulators

  7. Reaction between Hydrogen Sulfide and Limestone Calcines

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Svoboda, Karel; Trnka, Otakar; Čermák, Jiří

    2002-01-01

    Roč. 41, č. 10 (2002), s. 2392-2398 ISSN 0888-5885 R&D Projects: GA AV ČR IAA4072711; GA AV ČR IAA4072801 Keywords : hydrogen sulfide * limestone calcines * desulfurization Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.247, year: 2002

  8. Evaluation of Calcine Disposition Path Forward

    International Nuclear Information System (INIS)

    Birrer, S.A.; Heiser, M.B.

    2003-01-01

    This document describes an evaluation of the baseline and two alternative disposition paths for the final disposition of the calcine wastes stored at the Idaho Nuclear Technology and Engineering Center at the Idaho National Engineering and Environmental Laboratory. The pathways are evaluated against a prescribed set of criteria and a recommendation is made for the path forward

  9. Development and evaluation of alumina calcination

    International Nuclear Information System (INIS)

    Bennett, I.J.

    2000-01-01

    This thesis focuses on a number of aspects governing the transformation of gibbsite, via intermediate phases, to α-alumina. These aspects include the size and morphology of the gibbsite grains, the influence of additions of foreign elements, the effect of a mechanical treatment of the gibbsite prior to calcination, and combinations of these factors. The materials were characterised by scanning electron microscopy, X-ray diffraction and surface area measurements. For some of the calcined materials an attempt was made to sinter the powders to a dense body to investigate if any of the treatments during calcination had an effect on this process. The literature review covers the current state of understanding of the production of bulk alumina powder by the Bayer process and the phase changes seen on calcination of precursors to the stable α-alumina phase. A detailed description of the phase changes is given and the various routes and conditions necessary for the transformations to occur are considered. The transformations are examined in relation to the morphology of the crystals and the variables controlling the phase transformation route are discussed. Calcination in air showed that the size of the gibbsite grain governs the calcination route taken to reach oc-alumina. The standard gibbsites used in this work show a mixed calcination sequence transforming both via the boehmite phase, followed by the γ, δ and θ phases, and via the χ and κ phases. The formation of boehmite is attributed to retention of water vapour within the grain. Differences in morphology of the starting materials showed that for the range of materials seen, the morphology of the grain is less important than its size. The super fine material confirmed that a small grain size transforms via the non-boehmite route only, with the other gibbsites taking intermediate routes as for the standard gibbsites. Of the additions made prior to calcination, aluminium fluoride was found to reduce the

  10. Kinetic Study of Calcination of Jakura Limestone Using Power Rate ...

    African Journals Online (AJOL)

    National Research Institute for Chemical Technology, P.M. B 1052, Zaria, ... calcination of Jakura limestone was also found to be first order reaction with respect to CaCO3 ... Keywords: Jakura, limestone, calcination, kinetics, power law model.

  11. Dissolution studies with pilot plant and actual INTEC calcines

    International Nuclear Information System (INIS)

    Herbst, R.S.; Garn, T.G.

    1999-01-01

    The dissolution of Idaho Nuclear Technology and Engineering Center (INTEC) pilot plant calcines was examined to determine solubility of calcine matrix components in acidic media. Two representatives pilot plant calcine types were studied: Zirconia calcine and Zirconia/Sodium calcine. Dissolution of these calcines was evaluated using lower initial concentrations of nitric acid than used in previous tests to decrease the [H+] concentration in the final solutions. Lower [H+] concentrations contribute to more favorable TRUEX/SREX solvent extraction flowsheet performance. Dissolution and analytical results were also obtained for radioactive calcines produced using high sodium feeds blended with non-radioactive Al(NO 3 ) 3 solutions to dilute the sodium concentration and prevent bed agglomeration during the calcination process. Dissolution tests indicated >95 wt.% of the initial calcine mass can be dissolved using the baseline dissolution procedure, with the exception that higher initial nitric acid concentrations are required. The higher initial acid concentration is required for stoichiometric dissolution of the oxides, primarily aluminum oxide. Statistically designed experiments using pilot plant calcine were performed to determine the effect of mixing rate on dissolution efficiency. Mixing rate was determined to provide minimal effects on wt.% dissolution. The acid/calcine ratio and temperature were the predominate variables affecting the wt.% dissolution, a result consistent with previous studies using other similar types of pilot plant calcines

  12. Flash calcination of kaolinite rich clay and impact of process conditions on the quality of the calcines

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2016-01-01

    Use of properly calcined kaolinite rich clay (i.e., metakaolin) to offset part of CO2-intensive clinkers not only reduces CO2 footprint from cement industry but also improves the performance of concrete. However, calcination under inappropriately high temperatures or long retention times may...... suspension calciner. The model is validated by the experimental data (e.g., the degree of dehydroxylation and the density of the calcines). Based on the model, the impacts of process conditions and feed properties on the quality of the calcination products are thoroughly examined....

  13. The increase performance BMF-14 calcination unit

    International Nuclear Information System (INIS)

    Triyono

    2013-01-01

    The heating element of performance increase BMF-14 calcination unit has been installed. The activity includes: installation and function test heating element step by step. The main component includes: kanthal heating element type with size long 58,2 cm diameter 0,9 cm slot total 28, flexible cable resists heat 30 Amperes, band cable heat resists and flexible clamp. The heating elements installation includes from 3 groups and every groups have 4 heating elements to connectly series. Every group connecting to every phase RST and neutral for getting electric voltage 380 Volts follow contact relay 3 phases to controlling by digital temperature control. The resulting installation of heating element in the BMF-14 calcination unit showed that: BMF-14 calcination unit can be again of the setting temperature step by step. In the step I get optimal temperature 560 °C test time 1068 minutes with rate velocity heat 0 to 18,0 °C/minutes with current between 5,8 to 6,4 Amperes voltage 103 to 123 Volts (phase R and T). In the step II gets optimal temperature 600 °C test time 265 minutes getting rate velocity heat 0 to 40,3 °C/minutes with current 3,8 to 8,5 Amperes voltage 76 to 142 Volts (phase RST). In the step III gets optimal temperature 1000 °C test time 107 minutes getting rate velocity heat 0 to 53,5 °C/minutes with current 9,7 to 12,5 Amperes voltage 215 to 225 Volts (phase RST). (author)

  14. Waste Calcining Facility remote inspection report

    International Nuclear Information System (INIS)

    Patterson, M.W.; Ison, W.M.

    1994-08-01

    The purpose of the Waste Calcining Facility (WCF) remote inspections was to evaluate areas in the facility which are difficult to access due to high radiation fields. The areas inspected were the ventilation exhaust duct, waste hold cell, adsorber manifold cell, off-gas cell, calciner cell and calciner vessel. The WCF solidified acidic, high-level mixed waste generated during nuclear fuel reprocessing. Solidification was accomplished through high temperature oxidation and evaporation. Since its shutdown in 1981, the WCFs vessels, piping systems, pumps, off-gas blowers and process cells have remained contaminated. Access to the below-grade areas is limited due to contamination and high radiation fields. Each inspection technique was tested with a mock-up in a radiologically clean area before the equipment was taken to the WCF for the actual inspection. During the inspections, essential information was obtained regarding the cleanliness, structural integrity, in-leakage of ground water, indications of process leaks, indications of corrosion, radiation levels and the general condition of the cells and equipment. In general, the cells contain a great deal of dust and debris, as well as hand tools, piping and miscellaneous equipment. Although the building appears to be structurally sound, the paint is peeling to some degree in all of the cells. Cracking and spalling of the concrete walls is evident in every cell, although the east wall of the off-gas cell is the worst. The results of the completed inspections and lessons learned will be used to plan future activities for stabilization and deactivation of the facility. Remote clean-up of loose piping, hand tools, and miscellaneous debris can start immediately while information from the inspections is factored into the conceptual design for deactivating the facility

  15. Design and development of a rotary calciner for radiochemical waste

    International Nuclear Information System (INIS)

    Pande, D.P.; Sutar, V.D.; Sengar, P.B.S.

    1997-01-01

    Present experience and knowledge in handling of radioactive waste has led to identification of major thrust areas in the development of the treatment processes. In order to reduce evaporation and volatility losses in the vitrification facility, it is advantageous to carry out evaporation and calcination steps in another equipment like rotary calciner. Efforts have been directed for the engineering development of a Rotary Ball Kiln calciner. This paper highlights the important design features of the Rotary Ball Kiln Calciner for the radioactive waste. In this work, an attempt has been made to systematically evaluate the influence of process and design parameters. The results obtained on calcination will provide a design basis and rational methodology for the optimum utilization of these processes and equipment for volume reduction and calcination of the liquid waste

  16. Calcinating petroleum coke in a furnace with a rotating hearth

    Energy Technology Data Exchange (ETDEWEB)

    Akhmetov, M M; Ezhov, B M; Galeeva, Z G; Goriunov, V S; Karpinskaia, N N; Zaitseva, S A

    1980-01-01

    A scheme is described for an industrial device with a bottom furnace for calcinating coke from slow coking. The consumption and operational indicators of the process during the calcination of standard and needle cokes are given, together with data on the quality of dry and calcinated cokes under different conditions. The basic drawbacks in the operation of the device are described, and measures are proposed for increasing its operational effectiveness.

  17. Pilot-plant development of a Rover waste calcination flowsheet

    International Nuclear Information System (INIS)

    Birrer, S.A.

    1978-04-01

    Results of eight runs, six using the 10-cm dia and two using the 30-cm dia pilot-plant calciners, in which simulated first-cycle Rover waste was calcined, are described. Results of the tests showed that a feed blend consisting of one volume simulated first-cycle Rover waste and one or two volumes simulated first-cycle zirconium waste could not be successfully calcined. 5 figs., 8 tables

  18. Microwave heating application in calcination and SYNROC formation

    International Nuclear Information System (INIS)

    Ambashta, R.D.; Wattal, P.K.; Malav, R.K.; Mallik, G.K.

    2006-01-01

    Microwave for calcination of titanate based ceramic wasteform (SYNROC) is being reported for the first time in this paper. Although major constituents in SYNROC were non microwave active, the combination with microwave active constituents rendered the mixture calcinable. Calcine was sintered at 1150 degC under hot uniaxial conditions at an applied pressure of ∼30 MPa. XRD shows presence of major phases of SYNROC in the compacted sample. (author)

  19. Product removal and solids transport from fluidized-bed calciners

    International Nuclear Information System (INIS)

    Grimmett, E.S.; Munger, D.H.

    1978-09-01

    Methods of removing the solid product from pilot-plant and production fluidized-bed calciners, and transporting product to underground storage vaults are reported here. Testing of dense-phase solids transport systems in test loops during development of a 15-cm-diam. and 30-cm-diam. calciner are described. A lean-phase solid transport system is used with the Waste Calcining Facility. The results of some recent tests done in a lean-phase transport system connected to the 30-cm-diam. calciner are included in this report

  20. SYNROC production using a fluid bed calciner

    International Nuclear Information System (INIS)

    Ackerman, F.J.; Grens, J.Z.; Ryerson, F.J.; Hoenig, C.L.; Bazan, F.; Campbell, J.H.

    1982-01-01

    SYNROC is a titanate-based ceramic developed for immobilization of high-level nuclear reactor wastes in solid form. Fluid-bed SYNROC production permits slurry drying, calcining and redox to be carried out in a single unit. We present results of studies from two fluid beds; the Idaho Exxon internally-heated unit and the externally-heated unit constructed at Lawrence Livermore National laboratory. Bed operation over a range of temperature, feed rate, fluidizing rate and redox conditions indicate that high density, uniform particle-size SYNROC powders are produced which facilitate the densification step and give HUP parts with dense, well-developed phases and good leaching characteristics. 3 figures, 3 tables

  1. Calcination of kaolinite clay particles for cement production

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    2014-01-01

    Kaolinite rich clay particles calcined under certain conditions can attain favorable pozzolanic properties and can be used to substitute part of the CO2 intensive clinker in cement production. To better guide calcination of a clay material, a transient one-dimensional single particle model...

  2. Mission Need Statement: Calcine Disposition Project Major Systems Acquisition Project

    International Nuclear Information System (INIS)

    J. T. Beck

    2007-01-01

    This document identifies the need to establish the Calcine Disposition Project to determine and implement the final disposition of calcine including characterization, retrieval, treatment (if necessary), packaging, loading, onsite interim storage pending shipment to a repository or interim storage facility, and disposition of related facilities

  3. Modeling of calcination of single kaolinitic clay particle

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay; Yin, Chungen; Rosendahl, Lasse

    The present work aims at modeling of the calcination (dehydroxylation) process of clay particles, specifically kaolinite, and its thermal transformation. For such purpose, 1D single particle calcination model was developed based on the concept of shrinking core model to assess the dehydroxylation...

  4. Practical results of the MESA 1 line calcinator trial operation

    International Nuclear Information System (INIS)

    Napravnik, J.; Sazavsky, P.; Skaba, V.; Zahalka, F.; Vild, J.; Kulovany, J.

    1987-01-01

    Mobile calcination and cementation unit MESA 1 was designed and built by UJV Rez in cooperation with many enterprises, mainly with the Kralovopolske Strojirny Brno. This facility for direct fixation of liquid radioactive wastes was experimentally tested using model non-radioactive solutions and model and actual wastes from the Jaslovske Bohunice nuclear power plant. The calciner was run in trial operation at the Kralovopolske SAtrojirny Brno. A total of 1.3 m 3 of model solutions was processed into 180 kg of calcinate. The fixation of the calcinate in cement, the times of solidification and of hardening and the moisture content of concrete blocks were studied. The application was also tested of the calciner in drying ion exchangers from WWER-440 prior to their bituminization. Following the despatch of the cementation module to the Chernobyl nuclear power plant, the direct calcination module was tested at Dukovany together with an auxiliary module which makes possible self-contained calciner operation. Model non-radioactive solutions from the Dukovany nuclear power plant were treated containing H 3 BO 3 and NaNO 3 as main components. The usability in actual conditions of the mobile calcination and cementation unit for radioactive wastes was tested in a total of about 70 operating hours. (E.S.). 2 figs., 2 refs

  5. Properties of Formula 127 glass prepared with radioactive zirconia calcine

    International Nuclear Information System (INIS)

    Staples, B.A.; Pavlica, D.A.; Cole, H.S.

    1982-09-01

    Formula 127 glass has been developed to immobilize ICPP zirconia calcine. This glass has been prepared remotely on a laboratory scale basis with actual radioactive zirconia calcine retrieved after ten years of storage from Bin Set 2. The aqueous leachability of the glass produced was investigated and compared through application of the MCC-1, MCC-2 and Soxhlet leach tests with that of Formula 127 glass prepared with simulated calcine. The solid state properties of the glasses prepared with actual and simulated calcines were also measured by electron spectroscopy for chemical analysis (ESCA) and scanning electron microscopy energy dispersive x-ray (SEM-EDX). Based on the application of these leaching tests and analysis techniques the properties measured in this study are similar for 127 glass prepared with either simulated or radioactive calcine. 13 figures, 16 tables

  6. Energy saving plan for lime calcining kiln

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Lime calcining kilns operating in China are of old type, consuming more heat energy by 30% or more than the latest type kilns. For the purpose of the COP3 joint implementation, a renewal plan was discussed taking up Benxi Steel Group Company as the object. The new type kiln is a parallel flow energy regenerating (Maerz) kiln. It has as high thermal efficiency as 900 kcal/kg of product. Annual fuel conservation as converted into crude oil will be 7.49x10{sup 3} tons, annual fuel cost reduction will be 101,200,000 yuan, and annual reduction in CO2 emission will be 23,200 tons. The estimated cost required for the project will be 991 million yen, or 66,070,000 yuan if the exchange rate is assumed to be 15 yen to one yuan. The profitability was discussed based on using bank loans and the special environmental yen loan. The investment recovering period was calculated as 7.9 years. This provides no realizability as a project on the business base. However, China strongly desires renewal of the facilities because of discharge of dust from old type facilities, and inferior quality of lime products. The project could be a candidate without doubt if the CDM system will have been established. (NEDO)

  7. Calcination/dissolution testing for Hanford Site tank wastes

    International Nuclear Information System (INIS)

    Colby, S.A.; Delegard, C.H.; McLaughlin, D.F.; Danielson, M.J.

    1994-07-01

    Thermal treatment by calcination offers several benefits for the treatment of Hanford Site tank wastes, including the destruction of organics and ferrocyanides and an hydroxide fusion that permits the bulk of the mostly soluble nonradioactive constituents to be easily separated from the insoluble transuranic residue. Critical design parameters were tested, including: (1) calciner equipment design, (2) hydroxide fusion chemistry, and (3) equipment corrosion. A 2 gal/minute pilot plant processed a simulated Tank 101-SY waste and produced a free flowing 700 C molten calcine with an average calciner retention time of 20 minutes and >95% organic, nitrate, and nitrite destruction. Laboratory experiments using actual radioactive tank waste and the simulated waste pilot experiments indicate that 98 wt% of the calcine produced is soluble in water, leaving an insoluble transuranic fraction. All of the Hanford Site tank wastes can benefit from calcination/dissolution processing, contingent upon blending various tank waste types to ensure a target of 70 wt% sodium hydroxide/nitrate/nitrite fluxing agent. Finally, corrosion testing indicates that a jacketed nickel liner cooled to below 400 C would corrode <2 mil/year (0.05 mm/year) from molten calcine attack

  8. Calcination of the cerium concentrate to be cerium oxide

    International Nuclear Information System (INIS)

    Suyanti; MV Purwani

    2016-01-01

    Calcination of the cerium concentrate to be cerium oxide has done. The cerium concentrate were obtained from the Ce making process wear KBrO_3 and without using KBrO_3. The calcination were done with a variation of time 1, 2, 3 and 4 hours with the temperature variations of 700, 800 and 900°C. The easiest calcination of Ce concentrates to be CeO_2 containing majority of Ce(OH)_4 and contains least impurities as Th(OH)_4, (NH_4)_2Y(NO_3), H_4N_5O_1_2La, H_1_2N_3NdO_1_5 and N_3O_9Sm. On the calcination of Ce concentrates process results without using KBrO_3 1, the calcination temperature 900°C was obtained CeO_2 content of 73.53% for calcination time of 4 hours, has little difference when compared with the predictions and calculation result of complete calcination was equal 73.84%. (author)

  9. Assessment of soda ash calcination treatment of Turkish trona ore

    Directory of Open Access Journals (Sweden)

    Gezer Sibel

    2016-01-01

    Full Text Available Trona is relatively rare, non-metallic mineral, Na2CO3 · NaHCO3 · 2H2O. The pure material contains 70.3% sodium carbonate and by calcination the excess CO2 and water can be driven off, yielding natural soda ash. The terms soda ash and sodium carbonate are used interchangeably. Trona calcining is a key process step in production of soda ash (sodium carbonate anhydrate from the relatively cheap trona ore. The calcination reaction may proceeds in a sequence of steps. Depending on the conditions, it may result in formation of either sodium carbonate monohydrate (Na2CO3 · H2O, sodium sesquicarbonate or weigschederite (Na2CO3 · 3NaHCO3. The Beypazarı Turkish trona deposit is the second largest deposit in the world with the content of 84% trona. The decomposition of trona appeared to be a single stage process across the temperature range studied (150-200 °C with the representative samples of different size fractions in the draught up metallurgical furnace. The optimum particle size and calcination time were −6.35 mm and 30 minutes, respectively, at calcination temperature of 175 °C in a metallurgical furnace. Microwave-induced dry calcination of trona was possible and 5 minutes of calcination time at a power level of 900 was sufficient for complete calcination of −6.35 mm feed. This includes short time calcinations with the goal of improving economics and simplifying the thermal process.

  10. Study of as-synthesized and calcined hydrocalumites as possible ...

    Indian Academy of Sciences (India)

    Administrator

    ments. Finally, these solids were tested as antacids by using a synthetic gastric juice. Results showed that calcined samples were able to neutralize the synthetic gastric juice in more extension as an as-synthesized ..... D 2010 Appl. Clay Sci.

  11. Effect of calcination conditions of pork bone sludge on behaviour

    Indian Academy of Sciences (India)

    ... bone sludge from meat plant via two essentially different calcination methods using ... tissue and suitability for further investigations intended for medical grafting. ... The Alfred Meissner Higher School of Dental Engineering and Humanities, ...

  12. CSER 99-001: PFP LAB Dentirating calciner

    International Nuclear Information System (INIS)

    MILLER, E.M.; DOBBIN, K.D.

    1999-01-01

    A criticality safety evaluation report was prepared for the Plutonium Finishing Plant (PFP) laboratory denigrating calciner, located in Glovebox 188-1, that converts Pu(NO 3 ) 4 solutions to the high fired stable oxide PuO 2 . Fissile mass limits and volume limits are set for the glovebox for testing operations and training operators using only nitric acid feed to a plutonium oxide bed in the calciner

  13. Activity Based Startup Plan for Prototype Vertical Denitration Calciner

    International Nuclear Information System (INIS)

    SUTTER, C.S.

    1999-01-01

    Testing activation on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The restart of testing activities will require a review through an activity based startup process based upon Integrated Safety Management (ISM) principles to verify readiness. The Activity Based Startup Plan for the Prototype vertical Denitration Calciner has been developed for this process

  14. Fixation of calcined waste by bituminization or cementation

    International Nuclear Information System (INIS)

    Napravnik, J.; Kyrs, M.; Ditl, P.

    1983-01-01

    The overall concept is given of the combination of calcination with fixation into bitumen, cement etc. The design is shown of a calciner with the capacity of 10 L/h which was tested on real radioactive wastes for 2000 h. The geometrical and operating parameters of the apparatus have been optimized based on a statistical evaluation of the experiments. Wastes containing nitrates are calcined at 300-550 deg. C, yielding oxides. Wastes containing sulphates, carbonates, KMnO 4 , or borates are calcined at 150-330 deg. C, yielding soluble salts. The content of H 3 BO 4 and Na 2 B 4 O 7 and in some cases of sulphates in the calcinate retards hardening of the mixture with cement. Nitrates and detergents also interfere. The effect of the above components on the products mixed with bitumen is much less. Detergents can be decomposed at 200-300 deg. C; organic acids can be reacted with A1 salts to form insoluble substances lowering the leaching rate of Sr and Cs; small amounts of SiO 2 eliminate the effect of borates on cement hardening. The drawbacks of bituminization with bitumen emulsions are the complicated preparation of the emulsion, higher leaching rate of the product and low stability of the emulsion against breaking. The leachability was determined (1-50 days) of different products containing LWR wastes: 33% of concentrated waste in cement of calcination product stabilized with PVA exhibit approx. 8x10 - 3 g/cm 2 per day, 33% of calcine in cement approx. 3x10 - 3 ; 40% concentrate fixed with bitumen emulsion approx. 9x10 - 4 ; 50% calcine stabilized with PVA in bitumen, pilot-plant scale approx. 2x10 - 5 ; the same but on a laboratory scale approx. 1.10 - 5 . (author)

  15. High Temperature Calcination - MACT Upgrade Equipment Pilot Plant Test

    Energy Technology Data Exchange (ETDEWEB)

    Richard D. Boardman; B. H. O& #39; Brien; N. R. Soelberg; S. O. Bates; R. A. Wood; C. St. Michel

    2004-02-01

    About one million gallons of acidic, hazardous, and radioactive sodium-bearing waste are stored in stainless steel tanks at the Idaho Nuclear Technology and Engineering Center (INTEC), which is a major operating facility of the Idaho National Engineering and Environmental Laboratory. Calcination at high-temperature conditions (600 C, with alumina nitrate and calcium nitrate chemical addition to the feed) is one of four options currently being considered by the Department of Energy for treatment of the remaining tank wastes. If calcination is selected for future processing of the sodium-bearing waste, it will be necessary to install new off-gas control equipment in the New Waste Calcining Facility (NWCF) to comply with the Maximum Achievable Control Technology (MACT) standards for hazardous waste combustors and incinerators. This will require, as a minimum, installing a carbon bed to reduce mercury emissions from their current level of up to 7,500 to <45 {micro}g/dscm, and a staged combustor to reduce unburned kerosene fuel in the off-gas discharge to <100 ppm CO and <10 ppm hydrocarbons. The staged combustor will also reduce NOx concentrations of about 35,000 ppm by 90-95%. A pilot-plant calcination test was completed in a newly constructed 15-cm diameter calciner vessel. The pilot-plant facility was equipped with a prototype MACT off-gas control system, including a highly efficient cyclone separator and off-gas quench/venturi scrubber for particulate removal, a staged combustor for unburned hydrocarbon and NOx destruction, and a packed activated carbon bed for mercury removal and residual chloride capture. Pilot-plant testing was performed during a 50-hour system operability test January 14-16, followed by a 100-hour high-temperature calcination pilot-plant calcination run January 19-23. Two flowsheet blends were tested: a 50-hour test with an aluminum-to-alkali metal molar ratio (AAR) of 2.25, and a 50-hour test with an AAR of 1.75. Results of the testing

  16. Optimization of Calcine Blending During Retrieval From Binsets

    International Nuclear Information System (INIS)

    Taylor, D.D.; Mohr, C.M.; Nelson, L.O.

    2000-01-01

    This report documents a study performed during advanced feasibility studies for the INTEC Technology Development Facility (ITDF). The study was commissioned to provide information about functional requirements for the ITDF related to development of equipment and procedures for retrieving radioactive calcine from binset storage at the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). Calcine will be retrieved prior to treating it for permanent disposal in a national repository for high level waste. The objective this study was to estimate the degree of homogenization of the calcine that might be achieved through optimized retrieval and subsequent blending. Such homogenization has the potential of reducing the costs for treatment of the calcine and for qualifying of the final waste forms for acceptance at the repository. Results from the study indicate that optimized retrieval and blending can reduce the peak c oncentration variations of key components (Al, Zr, F) in blended batches of retrieved calcine. During un-optimized retrieval these variations are likely to be 81-138% while optimized retrieval can reduce them to the 5-10% range

  17. Optimization of Calcine Blending During Retrieval From Binsets; TOPICAL

    International Nuclear Information System (INIS)

    Taylor, D.D.; Mohr, C.M.; Nelson, L.O.

    2000-01-01

    This report documents a study performed during advanced feasibility studies for the INTEC Technology Development Facility (ITDF). The study was commissioned to provide information about functional requirements for the ITDF related to development of equipment and procedures for retrieving radioactive calcine from binset storage at the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). Calcine will be retrieved prior to treating it for permanent disposal in a national repository for high level waste. The objective this study was to estimate the degree of homogenization of the calcine that might be achieved through optimized retrieval and subsequent blending. Such homogenization has the potential of reducing the costs for treatment of the calcine and for qualifying of the final waste forms for acceptance at the repository. Results from the study indicate that optimized retrieval and blending can reduce the peak c oncentration variations of key components (Al, Zr, F) in blended batches of retrieved calcine. During un-optimized retrieval these variations are likely to be 81-138% while optimized retrieval can reduce them to the 5-10% range

  18. Optimization of Calcine Blending During Retrieval from Binsets

    International Nuclear Information System (INIS)

    Nelson, Lee Orville; Mohr, Charles Milton; Taylor, Dean Dalton

    2000-01-01

    This report documents a study performed during advanced feasibility studies for the INTEC Technology Development Facility (ITDF). The study was commissioned to provide information about functional requirements for the ITDF related to development of equipment and procedures for retrieving radioactive calcine from binset storage at the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). Calcine will be retrieved prior to treating it for permanent disposal in a national repository for high level waste. The objective this study was to estimate the degree of homogenization of the calcine that might be achieved through optimized retrieval and subsequent blending. Such homogenization has the potential of reducing the costs for treatment of the calcine and for qualifying of the final waste forms for acceptance at the repository. Results from the study indicate that optimized retrieval and blending can reduce the peak concentration variations of key components (Al, Zr, F) in blended batches of retrieved calcine. During un-optimized retrieval these variations are likely to be 81-138% while optimized retrieval can reduce them to the 5-10% range

  19. Calcined Waste Storage at the Idaho Nuclear Technology and Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    Staiger, M. Daniel, Swenson, Michael C.

    2011-09-01

    This comprehensive report provides definitive volume, mass, and composition (chemical and radioactivity) of calcined waste stored at the Idaho Nuclear Technology and Engineering Center. Calcine composition data are required for regulatory compliance (such as permitting and waste disposal), future treatment of the caline, and shipping the calcine to an off-Site-facility (such as a geologic repository). This report also contains a description of the calcine storage bins. The Calcined Solids Storage Facilities (CSSFs) were designed by different architectural engineering firms and built at different times. Each CSSF has a unique design, reflecting varying design criteria and lessons learned from historical CSSF operation. The varying CSSF design will affect future calcine retrieval processes and equipment. Revision 4 of this report presents refinements and enhancements of calculations concerning the composition, volume, mass, chemical content, and radioactivity of calcined waste produced and stored within the CSSFs. The historical calcine samples are insufficient in number and scope of analysis to fully characterize the entire inventory of calcine in the CSSFs. Sample data exist for all the liquid wastes that were calcined. This report provides calcine composition data based on liquid waste sample analyses, volume of liquid waste calcined, calciner operating data, and CSSF operating data using several large Microsoft Excel (Microsoft 2003) databases and spreadsheets that are collectively called the Historical Processing Model. The calcine composition determined by this method compares favorably with historical calcine sample data.

  20. Calcined Waste Storage at the Idaho Nuclear Technology and Engineering Center

    International Nuclear Information System (INIS)

    Staiger, M. Daniel; Swenson, Michael C.

    2011-01-01

    This comprehensive report provides definitive volume, mass, and composition (chemical and radioactivity) of calcined waste stored at the Idaho Nuclear Technology and Engineering Center. Calcine composition data are required for regulatory compliance (such as permitting and waste disposal), future treatment of the caline, and shipping the calcine to an off-Site-facility (such as a geologic repository). This report also contains a description of the calcine storage bins. The Calcined Solids Storage Facilities (CSSFs) were designed by different architectural engineering firms and built at different times. Each CSSF has a unique design, reflecting varying design criteria and lessons learned from historical CSSF operation. The varying CSSF design will affect future calcine retrieval processes and equipment. Revision 4 of this report presents refinements and enhancements of calculations concerning the composition, volume, mass, chemical content, and radioactivity of calcined waste produced and stored within the CSSFs. The historical calcine samples are insufficient in number and scope of analysis to fully characterize the entire inventory of calcine in the CSSFs. Sample data exist for all the liquid wastes that were calcined. This report provides calcine composition data based on liquid waste sample analyses, volume of liquid waste calcined, calciner operating data, and CSSF operating data using several large Microsoft Excel (Microsoft 2003) databases and spreadsheets that are collectively called the Historical Processing Model. The calcine composition determined by this method compares favorably with historical calcine sample data.

  1. Total oxidation of toluene over calcined trimetallic hydrotalcites type catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Palacio, Luz A. [Instituto Superior Tecnico, IBB - Centro de Engenharia Biologica e Quimica, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Grupo Catalizadores y Adsorbentes, Universidad de Antioquia 1-317, A.A. 1226 Medellin (Colombia); Velasquez, Juliana; Echavarria, Adriana [Grupo Catalizadores y Adsorbentes, Universidad de Antioquia 1-317, A.A. 1226 Medellin (Colombia); Faro, Arnaldo [Departamento de Fisicoquimica, Instituto de Quimica, Universidade Federal do Rio de Janeiro, Ilha do Fundao, CT bloco A, Rio de Janeiro (Brazil); Ramoa Ribeiro, F. [Instituto Superior Tecnico, IBB - Centro de Engenharia Biologica e Quimica, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ribeiro, M. Filipa, E-mail: filipa.ribeiro@ist.utl.pt [Instituto Superior Tecnico, IBB - Centro de Engenharia Biologica e Quimica, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2010-05-15

    Two trimetallic ZnCuAl and MnCuAl hydrotalcites have been successfully synthesized by a co-precipitation method. The manganese based material was identified as a new hydrotalcite phase. Both lamellar precursors were calcined at 450 and 600 deg. C and the resulting catalysts were tested on reaction of total oxidation of toluene. The solids were characterized by X-ray diffraction, thermal analysis, atomic absorption spectroscopy, Fourier transformed infrared spectroscopy, N{sub 2} adsorption and H{sub 2} temperature-programmed reduction. It was found that ZnCuAl materials are composed of copper and zinc oxides supported on alumina; while MnCuAl ones comprise basically spinel phases, which were not completely identified. The catalytic behavior of the calcined samples showed that Mn hydrotalcite calcined at 450 deg. C exhibited the best catalytic performance that corresponds to 100% toluene conversion into CO{sub 2} at about 300 deg. C.

  2. Fluidized bed system for calcination of high level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Pande, D P; Prasad, T L; Yadgiri, N K; Theyyunni, T K [Process Engineering and Systems Development Division, Bhabha Atomic Research Centre, Mumbai (India)

    1994-06-01

    During the operation of nuclear facilities significant quantities of radiochemical liquid effluents of different concentrations and varying chemical compositions are generated. These effluents contain activated radionuclides, corrosion products and fission products. The advantage of feeding the waste in solid form into the vitrifying equipment are multifold. Efforts are therefore made in many countries to calcine the high level waste, and obtain waste in the oxide form before the same is mixed with glass forming additives and fed into the melter unit. An experimental rig for fluidized bed calcination is constructed for carrying out the detailed investigation of this process, in order to adopt the same for plant scale application. To achieve better gas-solid contact and avoid raining down of solids, a distributor of bubble cap type was designed. A review of existing experience at various laboratories and design of new experimental facility for development of calciners are given. (author). 11 refs., 5 figs.

  3. Microstructural changes in porous hematite nanoparticles upon calcination

    DEFF Research Database (Denmark)

    Johnsen, Rune; Knudsen, Kenneth D.; Molenbroek, Alfons M.

    2011-01-01

    This combined study using small-angle neutron scattering (SANS), X-ray powder diffraction (XRPD), transmission electron microscopy (TEM) and adsorption isotherm techniques demonstrates radical changes in the microstructure of porous hematite (-Fe2O3) nanoparticles upon calcination in air. TEM....... The change in microstructure also causes a reduction in the surface area as calculated by gaseous adsorption. The XRPD and SANS data show that the crystallite and SANS particle sizes are virtually unchanged by calcination at 623 K. Calcination at 973 K induces a significant alteration of the sample. The XRPD...... data reveal that the crystallite size increases significantly, and the SANS and adsorption isotherm studies suggest that the specific surface area decreases by a factor of 5–6. The TEM images show that the particles are sintered into larger agglomerates, but they also show that parts of the porous...

  4. Total oxidation of toluene over calcined trimetallic hydrotalcites type catalysts

    International Nuclear Information System (INIS)

    Palacio, Luz A.; Velasquez, Juliana; Echavarria, Adriana; Faro, Arnaldo; Ramoa Ribeiro, F.; Ribeiro, M. Filipa

    2010-01-01

    Two trimetallic ZnCuAl and MnCuAl hydrotalcites have been successfully synthesized by a co-precipitation method. The manganese based material was identified as a new hydrotalcite phase. Both lamellar precursors were calcined at 450 and 600 deg. C and the resulting catalysts were tested on reaction of total oxidation of toluene. The solids were characterized by X-ray diffraction, thermal analysis, atomic absorption spectroscopy, Fourier transformed infrared spectroscopy, N 2 adsorption and H 2 temperature-programmed reduction. It was found that ZnCuAl materials are composed of copper and zinc oxides supported on alumina; while MnCuAl ones comprise basically spinel phases, which were not completely identified. The catalytic behavior of the calcined samples showed that Mn hydrotalcite calcined at 450 deg. C exhibited the best catalytic performance that corresponds to 100% toluene conversion into CO 2 at about 300 deg. C.

  5. Letter report: Evaluation of dryer/calciner technologies for testing

    International Nuclear Information System (INIS)

    Sevigny, G.

    1996-02-01

    This letter report describes some past experiences on the drying and calcination of radioactive materials or corresponding simulants; and the information needed from testing. The report also includes an assessment of informational needs including possible impacts to a full-scale plant. This includes reliability, maintenance, and overall size versus throughput. Much of the material was previously compiled and reported by Mike Elliott of PNL open-quotes Melter Performance Assessmentclose quotes and Larry Eisenstatt of SEG on contract to WHC in a letter to Rod Powell. Also, an annotated bibliography was prepared by Reagan Seymour of WHC. Descriptions of the drying and calciner technologies, development status, advantages and disadvantages of using a WFE or calciner, and recommendations for future testing are discussed in this report

  6. Techniques for detection of transition phases in calcined alumina

    International Nuclear Information System (INIS)

    Pandolfelli, V.C.; Folgueras-Dominguez, S.

    1987-01-01

    Detection of transition phases in alumina, is very important in the receiving control and calcination of aluminium hydroxide. The non alfa or transition phases difficults the processability and causes localized shrinkage on sintering compromising the dimensional and mechanical aspects of the product. In this research using refraction index, absorption of dyes, specific density, X-ray diffraction and scanning electron microscopy, analyses, are done in calcined hydroxides submited to different thermal treatments. The limits and facilities of each technique are discussed and compared. (Author) [pt

  7. Calcine Waste Storage at the Idaho Nuclear Technology and Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    M. D. Staiger

    1999-06-01

    A potential option in the program for long-term management of high-level wastes at the Idaho Nuclear Technology and Engineering Center (INTEC), at the Idaho National Engineering and Environmental Laboratory, calls for retrieving calcine waste and converting it to a more stable and less dispersible form. An inventory of calcine produced during the period December 1963 to May 1999 has been prepared based on calciner run, solids storage facilities operating, and miscellaneous operational information, which gives the range of chemical compositions of calcine waste stored at INTEC. Information researched includes calciner startup data, waste solution analyses and volumes calcined, calciner operating schedules, solids storage bin capacities, calcine storage bin distributor systems, and solids storage bin design and temperature monitoring records. Unique information on calcine solids storage facilities design of potential interest to remote retrieval operators is given.

  8. Process Design Concepts for Stabilization of High Level Waste Calcine

    Energy Technology Data Exchange (ETDEWEB)

    T. R. Thomas; A. K. Herbst

    2005-06-01

    The current baseline assumption is that packaging ¡§as is¡¨ and direct disposal of high level waste (HLW) calcine in a Monitored Geologic Repository will be allowed. The fall back position is to develop a stabilized waste form for the HLW calcine, that will meet repository waste acceptance criteria currently in place, in case regulatory initiatives are unsuccessful. A decision between direct disposal or a stabilization alternative is anticipated by June 2006. The purposes of this Engineering Design File (EDF) are to provide a pre-conceptual design on three low temperature processes under development for stabilization of high level waste calcine (i.e., the grout, hydroceramic grout, and iron phosphate ceramic processes) and to support a down selection among the three candidates. The key assumptions for the pre-conceptual design assessment are that a) a waste treatment plant would operate over eight years for 200 days a year, b) a design processing rate of 3.67 m3/day or 4670 kg/day of HLW calcine would be needed, and c) the performance of waste form would remove the HLW calcine from the hazardous waste category, and d) the waste form loadings would range from about 21-25 wt% calcine. The conclusions of this EDF study are that: (a) To date, the grout formulation appears to be the best candidate stabilizer among the three being tested for HLW calcine and appears to be the easiest to mix, pour, and cure. (b) Only minor differences would exist between the process steps of the grout and hydroceramic grout stabilization processes. If temperature control of the mixer at about 80„aC is required, it would add a major level of complexity to the iron phosphate stabilization process. (c) It is too early in the development program to determine which stabilizer will produce the minimum amount of stabilized waste form for the entire HLW inventory, but the volume is assumed to be within the range of 12,250 to 14,470 m3. (d) The stacked vessel height of the hot process vessels

  9. Restart plan for the prototype vertical denitration calciner

    Energy Technology Data Exchange (ETDEWEB)

    SUTTER, C.S.

    1999-09-01

    Testing activities on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The Restart Plan will govern the transition of the test program from the completion of the activity based startup review; through equipment checkout and surrogate material runs; to resumption of the testing program and transition to unrestricted testing.

  10. CALCIUM OXIDE CHARACTERISTICS PREPARED FROM AMBUNTEN’S CALCINED LIMESTONE

    Directory of Open Access Journals (Sweden)

    Fatimatul Munawaroh

    2018-05-01

    Full Text Available Calcium oxide (CaO and calcium carbonate (CaCO3 are widely used in industry. CaO and CaCO3 can be synthesized or derived from limestone. The purpose of this study to determine the characteristics of CaO calcined limestone from Ambunten Sumenep. Lime in calcined at 850 ° C for 6 hours. Characterization of X-ray fluorescence (XRF was conducted to determine the chemical composition of limestone, X-ray diffraction test (XRD to find the lime crystalline phase and FTIR test to determine the absorption of wave number. XRF test results showed that the limestone chemical composition consisted of Ca of 95.37% as the dominant element, Mg of 4.1%, Fe 0.17% and Y by 0.39%. The XRD test results showed that the limestone crystal phase is ankerite (Ca [Fe, Mg] [CO3] 2 and after the calcined phase calcination is vaterite (Ca [OH] 2, calcite (CaO and calcite (CaCO3. While the FTIR test results show that the CaO spectra are seen at 3741.24, 1417.12 and 874.14 cm-1.

  11. Inductive classification of operating data from a fluidized bed calciner

    International Nuclear Information System (INIS)

    O'Brien, B.H.

    1990-01-01

    A process flowsheet expert system for a fluidized bed calciner which solidifies high-level radioactive liquid waste was developed from pilot-plant data using a commercial, inductive classification program. After initial classification of the data, the resulting rules were inspected and adjusted to match existing knowledge of process chemistry. The final expert system predicts performance of process flowsheets based upon the chemical composition of the calciner feed and has been successfully used to identify potential operational problems prior to calciner pilot-plant testing of new flowsheets and to provide starting parameters for pilot-plant tests. By using inductive classification techniques to develop the initial rules from the calciner pilot-plant data and using existing process knowledge to verify the accuracy of these rules, an effective expert system was developed with a minimum amount of effort. This method may be applied for developing expert systems for other processes where numerous operating data are available and only general process chemistry effects are known

  12. Ninth Processing Campaign in the Waste Calcining Facility

    International Nuclear Information System (INIS)

    Childs, K.F.; Donovan, R.I.; Swenson, M.C.

    1982-04-01

    This report discusses the Ninth (and final) Processing Campaign at the Waste Calcining Facility. Several processing interruptions were experienced during this campaign and the emphasis of this report is on process and equipment performance with operating problems and corrective actions discussed in detail

  13. Physical and chemical characterization of synthetic calcined sludge

    International Nuclear Information System (INIS)

    Slates, R.V.; Mosley, W.C. Jr.; Tiffany, B.; Stone, J.A.

    1982-03-01

    Calcined synthetic sludge was chemically characterized in support of engineering studies to design a processing plant to solidify highly radioactive waste at the Savannah River Plant. An analytical technique is described which provides quantitative data by mass spectrometric analysis of gases evolved during thermogravimetric analysis without measurements of gas flow rates or mass spectrometer sensitivities. Scanning electron microprobe analysis, Mossbauer spectroscopy, and several other common analytical methods were also used. Calcined sludge consists primarily of amorphous particles of hydrous oxides with iron, manganese, nickel, and calcium distributed fairly uniformly throughout the powder. Iron, manganese, nickel, and calcium exist in forms that are highly insoluble in water, but aluminum, sulfate, nitrate, and sodium exhibit relative water solubilities that increase in the given order from 60% to 94%. Evolved gas analysis in a helium atmosphere showed that calcined sludge is completely dehydrated by heating to 400 0 C, carbon dioxide is evolved between 100 to 700 0 C with maximum evolution at 500 0 C, and oxygen is evolved between 400 and 1000 0 C. Evolved gas analyses are also reported for uncalcined sludge. A spinel-type oxide similar to NiFe 2 O 4 was detected by x-ray diffraction analysis at very low-level in calcined sludge

  14. Calcined eggshell (CES): An efficient natural catalyst for ...

    Indian Academy of Sciences (India)

    hydes with active methylene compounds using calcined eggshell (CES) as an efficient ... of the important reactions to achieve carbon–carbon ... solid catalyst for biodiesel production,24 as a catalyst ... which supports for adsorption of water on CaO and ... The organic phase .... After extraction of the product with ethylac-.

  15. Kinetic Study of Calcination of Jakura Limestone Using Power Rate ...

    African Journals Online (AJOL)

    The calcination of Jakura limestone was also found to be first order reaction with respect to CaCO3 concentration having average regression coefficient of 0.99. The temperature dependent terms were found using Arrhenius law and it was observed that the reaction temperature has a direct effect on the rate of reaction.

  16. Effect of Calcination and Reduction Temperatures on the Reduction ...

    African Journals Online (AJOL)

    2003-12-05

    Dec 5, 2003 ... the catalyst activity. The results obtained by Rathousky et al.,9 however, revealed that the pretreatment conditions had a significant effect on the catalytic properties of Co/Al2O3 and. Co/SiO2 catalysts. Turnover frequency (TOF) for the F-T reaction decreased with increasing calcination temperature for both.

  17. Restart plan for the prototype vertical denitration calciner

    International Nuclear Information System (INIS)

    SUTTER, C.S.

    1999-01-01

    Testing activities on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The Restart Plan will govern the transition of the test program from the completion of the activity based startup review; through equipment checkout and surrogate material runs; to resumption of the testing program and transition to unrestricted testing

  18. Screening Level Risk Assessment for the New Waste Calcining Facility

    Energy Technology Data Exchange (ETDEWEB)

    M. L. Abbott; K. N. Keck; R. E. Schindler; R. L. VanHorn; N. L. Hampton; M. B. Heiser

    1999-05-01

    This screening level risk assessment evaluates potential adverse human health and ecological impacts resulting from continued operations of the calciner at the New Waste Calcining Facility (NWCF) at the Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Engineering and Environmental Laboratory (INEEL). The assessment was conducted in accordance with the Environmental Protection Agency (EPA) report, Guidance for Performing Screening Level Risk Analyses at Combustion Facilities Burning Hazardous Waste. This screening guidance is intended to give a conservative estimate of the potential risks to determine whether a more refined assessment is warranted. The NWCF uses a fluidized-bed combustor to solidify (calcine) liquid radioactive mixed waste from the INTEC Tank Farm facility. Calciner off volatilized metal species, trace organic compounds, and low-levels of radionuclides. Conservative stack emission rates were calculated based on maximum waste solution feed samples, conservative assumptions for off gas partitioning of metals and organics, stack gas sampling for mercury, and conservative measurements of contaminant removal (decontamination factors) in the off gas treatment system. Stack emissions were modeled using the ISC3 air dispersion model to predict maximum particulate and vapor air concentrations and ground deposition rates. Results demonstrate that NWCF emissions calculated from best-available process knowledge would result in maximum onsite and offsite health and ecological impacts that are less then EPA-established criteria for operation of a combustion facility.

  19. Criticality safety analysis of a calciner exit chute

    International Nuclear Information System (INIS)

    Haught, C.F.; Basoglu, B.; Brewer, R.W.; Hollenback, D.F.; Wilkinson, A.D.; Dodds, H.L.

    1994-01-01

    Calcination of uranyl nitrate into uranium oxide is part of normal operations of some enrichment plants. Typically, a calciner discharges uranium oxide powder (U 3 O 8 ) into an exit chute that directs the powder into a receiving can located in a glove box. One possible scenario for a criticality accident is the exit chute becoming blocked with powder near its discharge. The blockage restricts the flow of powder causing the exit chute to become filled with the powder. If blockage does occur, the height of the powder could reach a level that would not be safe from a criticality point of view. In this analysis, the subcritical height limit is examined for 98% enriched U 3 O 8 in the exit chute with full water reflection and optimal water moderation. The height limit for ensuring criticality safety during such an accumulation is 28.2 cm above the top of the discharge pipe at the bottom of the chute. Chute design variations are also evaluated with full water reflection and optimal water moderation. Subcritical configurations for the exit chute variation are developed, but the configurations are not safe when combined with the calciner. To ensure criticality safety, modifications must be made to the calciner tube or safety measures must be implemented if these designs are to be utilized with 98% enriched material. A geometrically safe configuration for the exit chute is developed for a blockage of 20% enriched powder with full water reflection and optimal water moderation, and this configuration is safe when combined with the existing calciner

  20. In Vitro Studies Evaluating Leaching of Mercury from Mine Waste Calcine Using Simulated Human Body Fluids

    OpenAIRE

    Gray, John E.; Plumlee, Geoffrey S.; Morman, Suzette A.; Higueras, Pablo L.; Crock, James G.; Lowers, Heather A.; Witten, Mark L.

    2010-01-01

    In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almad?n, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute prim...

  1. Mathematical modeling of an in-line low-NOx calciner

    DEFF Research Database (Denmark)

    Iliuta, Ion; Dam-Johansen, Kim; Jensen, Lars Skaarup

    2002-01-01

    The reduction of the NOx content in in-line-calciner-type kiln systems can be made by optimization of the primary filing in the rotary kiln and of the secondary firing in the calciner. Because the optimization of calciner offers greater opportunities the mathematical modeling of this reactor...

  2. Calcined Waste Storage at the Idaho Nuclear Technology and Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    M. D. Staiger

    2007-06-01

    This report provides a quantitative inventory and composition (chemical and radioactivity) of calcined waste stored at the Idaho Nuclear Technology and Engineering Center. From December 1963 through May 2000, liquid radioactive wastes generated by spent nuclear fuel reprocessing were converted into a solid, granular form called calcine. This report also contains a description of the calcine storage bins.

  3. Corrosion monitoring of storage bins for radioactive calcines

    International Nuclear Information System (INIS)

    Hoffman, T.L.

    1975-01-01

    Highly radioactive liquid waste produced at the Idaho Chemical Processing Plant is calcined to a granular solid for long term storage in stainless steel bins. Corrosion evaluation of coupons withdrawn from these bins indicates excellent performance for the materials of construction of the bins. At exposure periods of up to six years the average penetration rates are 0.01 and 0.05 mils per year for Types 304 and 405 stainless steels, respectively. (auth)

  4. Improvements in or relating to calcining reducible compounds

    International Nuclear Information System (INIS)

    Cole, E.A.; Peterson, R.S.

    1974-01-01

    Apparatus is described for calcining compounds of uranium compounds to temperatures of up to about 1000 0 C to produce UO 2 powders of uniform quality and having an oxygen content of less than 2.2 atoms of oxygen per atom of uranium. The apparatus comprises discharge and cooling means having an inlet end operatively joined with an air tight seal to a rotating Kiln to receive hot UO 2 powder therefrom without contact with air. (author)

  5. Leaching properties and chemical compositions of calcines produced at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Staples, B.A.; Paige, B.E.; Rhodes, D.W.; Wilding, M.W.

    1980-01-01

    No significant chemical differences were determined between retrieved and fresh calcine based on chemical and spectrochemical analyses. Little can be derived from the amounts of the radioisotopes present in the retrieved calcine samples other than the ratios of strontium-90 to cesium-137 are typical of aged fission product. The variations in concentrations of radionuclides within the composite samples of each bin also reflect the differences in compositions of waste solutions calcined. In general the leaching characteristics of both calcines by distilled water are similar. In both materials the radionuclides of cesium and strontium were selectively leached at significant rates, although cesium leached much more completely from the alumina calcine than from the zirconia calcine. Cesium and strontium are probably contained in both calcines as nitrate salts and also as fluoride salts in zirconia calcine, all of which are at least slightly soluble in water. Radionuclides of cerium, ruthenium, and plutonium in both calcines were highly resistant to leaching and leached at rates similar to or less than those of the matrix elements. These elements exist as polyvalent metal ions in the waste solutions before calcination and they probably form insoluble oxides and fluorides in the calcine. The relatively slow leaching of nitrate ion from zirconia calcine and radiocesium from both calcines suggests that the calcine matrix in some manner prevents complete or immediate contact of the soluble ions with water. Whether radiostrontium forms slightly fluoride salts or forms nitrate salts which are protected in the same manner as radiocesium is unknown. Nevertheless, selective leaching of cesium and strontim is retarded in some manner by the calcine matrix

  6. Interim status of vertical calciner testing through calendar year 1996

    International Nuclear Information System (INIS)

    Compton, J.A.

    1998-01-01

    A prototype vertical calciner was constructed and tested for use in converting plutonium solutions to dry plutonium dioxide in the Hanford Plutonium Finishing Plant. Six non-radioactive runs were completed in June and July, 1995. Fourteen runs with plutonium nitrate solutions were completed between September, 1995 and August, 1996. Equipment modifications were made following those runs. The test runs with plutonium have converted 62.3 L of feed solution containing 11.1 kg of plutonium into dry plutonium dioxide containing 8.5 kg of plutonium. The decrease in product plutonium content is primarily due to plutonium accumulation within the calciner powder bed from particle compaction. Nine of the eleven product batches have had Losses On Ignition that met the storage criterion of less than 0.5 weight percent at 950 C. The highest Loss On Ignition found was 0.718 weight percent. Initial problems with agitator shaft binding and breakage of bushings have been eliminated. A feed pump control problem has been found and the pump replaced. Improvement in scrubber efficiency is needed. Future runs are planned to confirm that (1) the remainder of product meets the Loss On Ignition criterion, (2) the replacement feedpump works as needed, and (3) the scrubber efficiency improves. The operating staff for the production calciner may also be observing the prototype's runs to gain familiarity with the process and equipment

  7. Synthesis of type A zeolite from calcinated kaolin

    International Nuclear Information System (INIS)

    Rodrigues, E.C.; Neves, R.F.; Souza, J.A.S.; Moraes, C.G.; Macedo, E.N.

    2011-01-01

    The mineral production has caused great concern in environmental and industrial scenario due to the effects caused to the environment. The industries of processing kaolin for paper are important economically for the state of Para, but produce huge quantities of tailings, which depend on large areas to be stocked. This material is rich in silico-aluminates can be recycled and used as raw material for other industries. The objective is to synthesize zeolite A at different temperatures of calcination and synthesis. The starting materials and synthesis of zeolite A have been identified and characterized through analysis of X-ray diffraction (DRX) and scanning electron microscopy (MEV). The synthesis process of zeolite A, using as source of silica and the aluminum metakaolin, which was calcined at temperatures of 700 ° C and 800 ° C for 2 hours of landing in a burning furnace type muffle. Observed in relation to the calcination of kaolin as the main phase, the metakaolin. This is just a removal of water from its structure, so we opted for the lower temperature, less energy consumption. The synthesis process of zeolite A, produced good results for the formation of zeolites type A, which were characterized with high purities. (author)

  8. Characterization of norm sources in petroleum coke calcining processes - 16314

    International Nuclear Information System (INIS)

    Hamilton, Ian S.; Halter, Donald A.; Fruchtnicht, Erich H.; Arno, Matthew G.; Haumann, Donald F

    2009-01-01

    Petroleum coke, or 'petcoke', is a waste by-product of the oil refining industry. The majority of petcoke consumption is in energy applications; catalyst coke is used as refinery fuel, anode coke for electricity conduction, and marketable coke for heating cement kilns. Roskill has predicted that long-term growth in petroleum coke production will be maintained, and may continue to increase slightly through 2012. Petcoke must first be calcined to drive off any undesirable petroleum by-products that would shorten the coke product life cycle. As an example, the calcining process can take place in large, rotary kilns heated to maximum temperatures as high as approximately 1400-1540 deg. C. The kilns and combustion/settling chambers, as well as some cooler units, are insulated with refractory bricks and other, interstitial materials, e.g., castable refractory materials, to improve the efficiency of the calcining process. The bricks are typically made of 70-85-percent bauxite, and are slowly worn away by the calcining process; bricks used to line the combustion chambers wear away, as well, but at a slower rate. It has been recognized that the refractory materials contain slight amounts of naturally occurring radioactive materials (NORM) from the uranium- and thorium-decay series. Similarly, low levels of NORM could be present in the petcoke feed stock given the nature of its origin. Neither the petcoke nor the refractory bricks represent appreciable sources of radiation or radioactive waste. However, some of the demolished bricks that have been removed from service because of the aforementioned wearing process have caused portal alarms to activate at municipal disposal facilities. This has lead to the current investigation into whether there is a NORM concentrating mechanism facilitated by the presence of the slightly radioactive feed stock in the presence of the slightly radioactive refractory materials, at calcining-zone temperatures. Research conducted to date has been

  9. The influence of calcination on the physical and chemical properties of petroleum and mixed cokes

    Energy Technology Data Exchange (ETDEWEB)

    Sikora, K; Syrek, H

    1980-01-01

    Freshly prepared petroleum and coal-petroleum cokes, before utilization for the production of various materials, are subjected to calcining--thermal treatment in a neutral or reducing atmosphere without the admission of air at less than or equal to 1400/sup 0/. During calcining, stabilization of the physical and chemical properties of the cokes takes place. The properties of the obtained coke depend chiefly on the calcining time and temperature. During calcining, volatile substances are removed almost completely from the coke; the coke density is increased, and its structure is put in order; the electrical conductivity is improved; the mechanical strength is increased; and the reactivity of the coke is decreased. Laboratory studies were conducted on calcining mixed coal-petroleum cokes of two grades at 1200, 1250, and 1300/sup 0/ for 2-6 h. In the calcining products the content of volatile substances, the ash content, S content, and density were determined. It was ascertained that calcining of mixed coal-petroleum cokes goes analogously to calcining of pure petroleum cokes. Raising the temperature and increasing the time of calcining has a substantial effect on improvement of coke physical and chemical properties. For high-quality coke, calcining is to be carried out at greater than or equal to 1300/sup 0/ for 4-6 h, for ordinary coke at > 1200/sup 0/ and greater than or equal to 4 h. The results are regarded as starting data for an industrial study of the calcining process.

  10. Calcination of Rod-like Hydroxyapatite Nanocrystals with an Anti-sintering Agent Surrounding the Crystals

    International Nuclear Information System (INIS)

    Okada, M.; Furuzono, T.

    2007-01-01

    Sintering-free nanocrystals of calcined hydroxyapatite (HAp) having a rod-like morphology were fabricated by calcination at 800 deg. C for 1 h with an anti-sintering agent surrounding original HAp particles and the agent was subsequently removed after calcination. The original HAp particles having a rod-like morphology with a size ranging from 30 to 80 nm (short axis) and 300 to 500 nm (long axis) were prepared by wet chemical process, and poly(acrylic acid, calcium salt) (PAA-Ca) was used as the anti-sintering agent. In the case of calcination without additives, the mean size of HAp crystals dispersed in an ethanol medium increased by about 4 times and the specific surface area of the crystals exhibited a 25% decrease compared to those of the original HAp particles because of calcination-induced sintering among the crystals. On the other hand, the HAp crystals calcined with the anti-sintering agent, PAA-Ca, could be dispersed in an ethanol medium at the same size as the original particles, and they preserved the specific surface area after calcination. These results indicate that PAA-Ca and/or its thermally decomposed product, CaO, surrounded the HAp particles and protected them against calcination-induced sintering during calcination. The HAp crystals calcined with PAA-Ca showed high crystallinity, and no other calcium phosphate phases could be detected after washing with water

  11. Advanced fluid bed calciner information on IR-100 award

    International Nuclear Information System (INIS)

    Druby, M.C.; Owen, T.J.; Klem, M.J.

    1986-01-01

    The advanced fluidized bed calciner provides time, temperature and turbulence to change a liquid slurry such as ammonium diuranate into a uranium dioxide powder. The liquid is sprayed into a hot chamber (up to 700 0 C) which includes thousands of tiny metal beads, about the size of BB's. The constantly moving beads provide an efficient heat transfer media for the immediate transformation of the slurry droplets into dry particles of powder, which are carried out by hot nitrogen gas and recovered in a collector

  12. Remote process connectors for the new waste calcining facility

    International Nuclear Information System (INIS)

    Jacobs, R.T.; Carter, J.A.; Hohback, A.C.

    1978-01-01

    The remote process connectors developed, used, and tested at the Remote Maintenance Development Facility are described. These connectors, including the three-bolt kinematic-graphite flange and watertight electrical connectors, are assembled on master jigs (holding-welding fixture) to form interchangeable pump and valve loop assemblies. These assemblies, with their guide-in platforms, make possible a method of performing remote maintenance at the New Waste Calcining Facility which is a departure from methods that until now have been the standard of the industry

  13. Retrieval System for Calcined Waste for the Idaho Cleanup Project - 12104

    Energy Technology Data Exchange (ETDEWEB)

    Eastman, Randy L.; Johnston, Beau A.; Lower, Danielle E. [CH2M-WG Idaho, LLC. The Idaho Cleanup Project at the Idaho National Laboratory (United States)

    2012-07-01

    This paper describes the conceptual approach to retrieve radioactive calcine waste, hereafter called calcine, from stainless steel storage bins contained within concrete vaults. The retrieval system will allow evacuation of the granular solids (calcine) from the storage bins through the use of stationary vacuum nozzles. The nozzles will use air jets for calcine fluidization and will be able to rotate and direct the fluidization or displacement of the calcine within the bin. Each bin will have a single retrieval system installed prior to operation to prevent worker exposure to the high radiation fields. The addition of an articulated camera arm will allow for operations monitoring and will be equipped with contingency tools to aid in calcine removal. Possible challenges (calcine bridging and rat-holing) associated with calcine retrieval and transport, including potential solutions for bin pressurization, calcine fluidization and waste confinement, are also addressed. The Calcine Disposition Project has the responsibility to retrieve, treat, and package HLW calcine. The calcine retrieval system has been designed to incorporate the functions and technical characteristics as established by the retrieval system functional analysis. By adequately implementing the highest ranking technical characteristics into the design of the retrieval system, the system will be able to satisfy the functional requirements. The retrieval system conceptual design provides the means for removing bulk calcine from the bins of the CSSF vaults. Top-down vacuum retrieval coupled with an articulating camera arm will allow for a robust, contained process capable of evacuating bulk calcine from bins and transporting it to the processing facility. The system is designed to fluidize, vacuum, transport and direct the calcine from its current location to the CSSF roof-top transport lines. An articulating camera arm, deployed through an adjacent access riser, will work in conjunction with the

  14. Precipitation of plutonium (III) oxalate and calcination to plutonium oxide

    International Nuclear Information System (INIS)

    Esteban, A.; Orosco, E.H.; Cassaniti, P.; Greco, L.; Adelfang, P.

    1989-01-01

    The plutonium based fuel fabrication requires the conversion of the plutonium nitrate solution from nuclear fuel reprocessing into pure PuO2. The conversion method based on the precipitation of plutonium (III) oxalate and subsequent calcination has been studied in detail. In this procedure, plutonium (III) oxalate is precipitated, at room temperature, by the slow addition of 1M oxalic acid to the feed solution, containing from 5-100 g/l of plutonium in 1M nitric acid. Before precipitation, the plutonium is adjusted to trivalent state by addition of 1M ascorbic acid in the presence of an oxidation inhibitor such as hydrazine. Finally, the precipitate is calcinated at 700 deg C to obtain PuO2. A flowsheet is proposed in this paper including: a) A study about the conditions to adjust the plutonium valence. b) Solubility data of plutonium (III) oxalate and measurements of plutonium losses to the filtrate and wash solution. c) Characterization of the obtained products. Plutonium (III) oxalate has several potential advantages over similar conversion processes. These include: 1) Formation of small particle sizes powder with good pellets fabrication characteristics. 2) The process is rather insensitive to most process variables, except nitric acid concentration. 3) Ambient temperature operations. 4) The losses of plutonium to the filtrate are less than in other conversion processes. (Author) [es

  15. Chloride Ingress in Chemically Activated Calcined Clay-Based Cement

    Directory of Open Access Journals (Sweden)

    Joseph Mwiti Marangu

    2018-01-01

    Full Text Available Chloride-laden environments pose serious durability concerns in cement based materials. This paper presents the findings of chloride ingress in chemically activated calcined Clay-Ordinary Portland Cement blended mortars. Results are also presented for compressive strength development and porosity tests. Sampled clays were incinerated at a temperature of 800°C for 4 hours. The resultant calcined clay was blended with Ordinary Portland Cement (OPC at replacement level of 35% by mass of OPC to make test cement labeled PCC35. Mortar prisms measuring 40 mm × 40 mm × 160 mm were cast using PCC35 with 0.5 M Na2SO4 solution as a chemical activator instead of water. Compressive strength was determined at 28th day of curing. As a control, OPC, Portland Pozzolana Cement (PPC, and PCC35 were similarly investigated without use of activator. After the 28th day of curing, mortar specimens were subjected to accelerated chloride ingress, porosity, compressive strength tests, and chloride profiling. Subsequently, apparent diffusion coefficients (Dapp were estimated from solutions to Fick’s second law of diffusion. Compressive strength increased after exposure to the chloride rich media in all cement categories. Chemically activated PCC35 exhibited higher compressive strength compared to nonactivated PCC35. However, chemically activated PCC35 had the least gain in compressive strength, lower porosity, and lower chloride ingress in terms of Dapp, compared to OPC, PPC, and nonactivated PCC35.

  16. Fluidized-bed calcination of simulated commercial high-level radioactive wastes

    International Nuclear Information System (INIS)

    Freeby, W.A.

    1975-11-01

    Work is in progress at the Idaho Chemical Processing Plant to verify process flowsheets for converting simulated commercial high-level liquid wastes to granular solids using the fluidized-bed calcination process. Primary emphasis in the series of runs reported was to define flowsheets for calcining simulated Allied-General Nuclear Services (AGNS) waste and to evaluate product properties significant to calcination, solids storage, or post treatment. Pilot-plant studies using simulated high-level acid wastes representative of those to be produced by Nuclear Fuel Services, Inc. (NFS) are also included. Combined AGNS high-level and intermediate-level waste (0.26 M Na in blend) was successfully calcined when powdered iron was added (to result in a Na/Fe mole ratio of 1.0) to the feed to prevent particle agglomeration due to sodium nitrate. Long-term runs (approximately 100 hours) showed that calcination of the combined waste is practical. Concentrated AGNS waste containing sodium at concentrations less than 0.2 M were calcined successfully; concentrated waste containing 1.13 M Na calcined successfully when powdered iron was added to the feed to suppress sodium nitrate formation. Calcination of dilute AGNS waste by conventional fluid-bed techniques was unsuccessful due to the inability to control bed particle size--both particle size and bed level decreased. Fluid-bed solidification of AGNS dilute waste at conditions in which most of the calcined solids left the calciner vessel with the off-gas was successful. In such a concept, the steady-state composition of the bed material would be approximately 22 wt percent calcined solids deposited on inert particles. Calcination of simulated NFS acid waste indicated that solidification by the fluid-bed process is feasible

  17. 46 CFR 148.04-17 - Petroleum coke, calcined, at 130 °F or above.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Petroleum coke, calcined, at 130 °F or above. 148.04-17...-17 Petroleum coke, calcined, at 130 °F or above. (a) The requirements of this part do not apply to bulk shipments of petroleum coke, calcined, on any vessel when the material is less than 130 °F. (b...

  18. In vitro studies evaluating leaching of mercury from mine waste calcine using simulated human body fluids

    Science.gov (United States)

    Gray, John E.; Plumlee, Geoffrey S.; Morman, Suzette A.; Higueras, Pablo L.; Crock, James G.; Lowers, Heather A.; Witten, Mark L.

    2010-01-01

    In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almadén, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute primary ore or compounds formed during Hg retorting. Elevated leachate Hg concentrations were found during calcine leaching using a simulated gastric fluid (as much as 6200 μg of Hg leached/g sample). Elevated Hg concentrations were also found in calcine leachates using a simulated lung fluid (as much as 9200 μg of Hg leached/g), serum-based fluid (as much as 1600 μg of Hg leached/g), and water of pH 5 (as much as 880 μg of Hg leached/g). The leaching capacity of Hg is controlled by calcine mineralogy; thus, calcines containing soluble Hg compounds contain higher leachate Hg concentrations. Results indicate that ingestion or inhalation of Hg mine-waste calcine may lead to increased Hg concentrations in the human body, especially through the ingestion pathway.

  19. Experimental study on the effect of calcination on the volcanic ash activity of diatomite

    Science.gov (United States)

    Xiao, Liguang; Pang, Bo

    2017-09-01

    The volcanic ash activity of diatomite was studied under the conditions of aerobic calcination and vacuum calcination by the combined water rate method, it was characterized by XRD, BET and SEM. The results showed that the volcanic ash activity of diatomite under vacuum conditions was higher than that of aerobic calcination, 600°C vacuum calcination 2h, the combined water rate of diatomite-Ca(OH)2-H2O system was increased from 6.24% to 71.43%, the volcanic ash activity reached the maximum value, the specific surface

  20. Dissolution of two NWCF calcines: Extent of dissolution and characterization of undissolved solids

    International Nuclear Information System (INIS)

    Brewer, K.N.; Herbst, R.S.; Tranter, T.J.

    1995-01-01

    A study was undertaken to determine the dissolution characteristics of two NWCF calcine types. A two-way blended calcine made from 4 parts nonradioactive aluminum nitrate and one part WM-102 was studied to determine the extent of dissolution for aluminum-type calcines. A two-way blend of 3.5 parts fluorinel waste from WM-187 and 1 part sodium waste from WM-185 was used to determine the extent of dissolution for zirconium-type calcines. This study was necessary to develop suitable aqueous separation flowsheets for the partitioning of actinides and fission products from ICPP calcines and to determine the disposition of the resulting undissolved solids (UDS). The dissolution flowsheet developed by Herbst was used to dissolve these two NWCF calcine types. Results show that greater than 95 wt% of aluminum and zirconium calcine types were dissolved after a single batch contact with 5 M HNO 3 . A characterization of the UDS indicates that the weight percent of TRU elements in the UDS resulting from both calcine type dissolutions increases by approximately an order of magnitude from their concentrations prior to dissolution. Substantial activities of cesium and strontium are also present in the UDS resulting from the dissolution of both calcine types. Multiple TRU, Cs, and Sr analyses of both UDS types show that these solids are relatively homogeneous. From this study, it is estimated that between 63.5 and 635 cubic meters of UDS will be generated from the dissolution of 3800 M 3 of calcine. The significant actinide and fission product activities in these UDS will preclude their disposal as low-level waste. If the actinide and fission activity resulting from the UDS is the only considered source in the dissolved calcine solutions, an estimated 99.9 to 99.99 percent of the solids must be removed from this solution for it to meet non-TRU Class A low-level waste

  1. Interfacial interactions between calcined hydroxyapatite nanocrystals and substrates.

    Science.gov (United States)

    Okada, Masahiro; Furukawa, Keiko; Serizawa, Takeshi; Yanagisawa, Yoshihiko; Tanaka, Hidekazu; Kawai, Tomoji; Furuzono, Tsutomu

    2009-06-02

    Interfacial interactions between calcined hydroxyapatite (HAp) nanocrystals and surface-modified substrates were investigated by measuring adsorption behavior and adhesion strength with a quartz crystal microbalance (QCM) and a contact-mode atomic force microscope (AFM), respectively. The goal was to develop better control of HAp-nanocrystal coatings on biomedical materials. HAp nanocrystals with rodlike or spherical morphology were prepared by a wet chemical process followed by calcination at 800 degrees C with an antisintering agent to prevent the formation of sintered polycrystals. The substrate surface was modified by chemical reaction with a low-molecular-weight compound, or graft polymerization with a functional monomer. QCM measurement showed that the rodlike HAp nanocrystals adsorbed preferentially onto anionic COOH-modified substrates compared to cationic NH2- or hydrophobic CH3-modified substrates. On the other hand, the spherical nanocrystals adsorbed onto NH2- and COOH-modified substrates, which indicates that the surface properties of the HAp nanocrystals determined their adsorption behavior. The adhesion strength, which was estimated from the force required to move the nanocrystal in contact-mode AFM, on a COOH-grafted substrate prepared by graft polymerization was almost 9 times larger than that on a COOH-modified substrate prepared by chemical reaction with a low-molecular-weight compound, indicating that the long-chain polymer grafted on the substrate mitigated the surface roughness mismatch between the nanocrystal and the substrate. The adhesion strength of the nanocrystal bonded covalently by the coupling reaction to a Si(OCH3)-grafted substrate prepared by graft polymerization was approximately 1.5 times larger than that when adsorbed on the COOH-grafted substrate.

  2. Model of fragmentation of limestone particles during thermal shock and calcination in fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Saastamoinen, J.; Pikkarainen, T.; Tourunen, A.; Rasanen, M.; Jantti, T. [VTT Technical Research Center, Jyvaskyla (Finland)

    2008-11-15

    Fragmentation of limestone due to thermal shock and calcination in a fluidised bed was studied through experiments and modelling. The time for heating was estimated by model calculations and the time for calcination by measurements. Fragmentation due to thermal shock was carried out by experiments in a CO{sub 2} atmosphere in order to prevent the effect of calcination. It was found to be much less than fragmentation due to calcination. Average particle sizes before and after fragmentation are presented for several types of limestone. The effects of particle size and gas composition on the primary fragmentation were studied through experiments. Increasing the fluidisation velocity increased the tendency to fragment. The evolution of the particle size distribution (PSD) of limestone particles due to thermal shock and during calcination (or simultaneous calcination and sulphation) were calculated using a population balance model. Fragmentation due to thermal shock is treated as an instantaneous process. The fragmentation frequency during calcination is presented as exponentially decaying over time. In addition to the final PSD, this model also predicts the PSD during the calcination process. The fragmentation was practically found to end after 10 min. Furthermore. a population balance method to calculate the particle size distribution and amount of limestone in fluidised beds in dynamic and steady state, when feeding history is known, is presented.

  3. Model for the sulfidation of calcined limestone and its use in reactor models.

    NARCIS (Netherlands)

    Heesink, Albertus B.M.; Brilman, Derk Willem Frederik; van Swaaij, Willibrordus Petrus Maria

    1998-01-01

    A mathematical model describing the sulfidation of a single calcined limestone particle was developed and experimentally verified. This model, which includes no fitting parameters, assumes a calcined limestone particle to consist of spherical grains of various sizes that react with H2S according to

  4. A conceptual and calculational model for gas formation from impure calcined plutonium oxides

    International Nuclear Information System (INIS)

    Lyman, John L.; Eller, P. Gary

    2000-01-01

    Safe transport and storage of pure and impure plutonium oxides requires an understanding of processes that may generate or consume gases in a confined storage vessel. We have formulated conceptual and calculational models for gas formation from calcined materials. The conceptual model for impure calcined plutonium oxides is based on the data collected to date

  5. Calcination effects on CeZrOx geometry and styrene production from ethylbenzene

    NARCIS (Netherlands)

    Kovacevic, M.; Brunet Espinosa, Roger; Lefferts, Leonardus; Mojet, Barbara

    2014-01-01

    A series of CeZrOx catalysts was prepared by calcination of hydrothermally obtained metal oxide precipitate at increasing temperatures. The samples were characterized by HRSEM, XRD and Raman spectroscopy, showing a change in morphology and particle size as a function of calcination temperature.

  6. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    International Nuclear Information System (INIS)

    COMPTON, J.A.

    1999-01-01

    A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium rich solids. The calciner and some of its associated equipment were previously tested with non-radioactive chemicals to demonstrate operability

  7. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    Energy Technology Data Exchange (ETDEWEB)

    COMPTON, J.A.

    1999-10-05

    A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium rich solids. The calciner and some of its associated equipment were previously tested with non-radioactive chemicals to demonstrate operability.

  8. Influence of calcination temperature on the structure and morphology of HAp bioceramics

    International Nuclear Information System (INIS)

    Teixeira, C.M.L.; Santos, P.T.A.; Rodrigues, P.A.; Costa, A.C.F.M.

    2012-01-01

    This study aimed to evaluate the influence of calcination temperature on the structure and morphology of samples of hydroxyapatite (HAp) synthesized by the wet method. For hydroxyapatite was used as precursor solutions of calcium hydroxide and phosphoric acid 1M solution of calcium hydroxide was stirred and heated to 80 ° C and then dropwise with a solution of phosphoric acid. After the liquid was evaporated without an oven at 110 ° C and sieved. The sample of PA as synthesized was submitted to calcination at 900 °C and 1100 °C / 2 hours. The samples as synthesized and after calcination were characterized by XRD, XRF, FTIR, SEM. The XRD showed the presence of phase hydroxyapatite for samples without calcining and both calcination temperatures studied. FTIR spectra showed bands group and PO 4 3- , CO 3 2- . Through the SEM micrograph, there is the formation of agglomerates in the form of porous flakes approximately spherical shape. (author)

  9. LITERATURE REVIEW OF PUO2 CALCINATION TIME AND TEMPERATURE DATA FOR SPECIFIC SURFACE AREA

    Energy Technology Data Exchange (ETDEWEB)

    Daniel, G.

    2012-03-06

    The literature has been reviewed in December 2011 for calcination data of plutonium oxide (PuO{sub 2}) from plutonium oxalate Pu(C{sub 2}O{sub 4}){sub 2} precipitation with respect to the PuO{sub 2} specific surface area (SSA). A summary of the literature is presented for what are believed to be the dominant factors influencing SSA, the calcination temperature and time. The PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} calcination data from this review has been regressed to better understand the influence of calcination temperature and time on SSA. Based on this literature review data set, calcination temperature has a bigger impact on SSA versus time. However, there is still some variance in this data set that may be reflecting differences in the plutonium oxalate preparation or different calcination techniques. It is evident from this review that additional calcination temperature and time data for PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} needs to be collected and evaluated to better define the relationship. The existing data set has a lot of calcination times that are about 2 hours and therefore may be underestimating the impact of heating time on SSA. SRNL recommends that more calcination temperature and time data for PuO{sub 2} from Pu(C{sub 2}O{sub 4}){sub 2} be collected and this literature review data set be augmented to better refine the relationship between PuO{sub 2} SSA and its calcination parameters.

  10. Comparative evaluation of glasses reprocessing and reversible conditioning of calcinates

    International Nuclear Information System (INIS)

    Boen, R.

    2000-01-01

    Fission products and minor actinides separated during the spent fuel reprocessing treatment are industrially vitrified on-line and thus confined inside a glass matrix with admittedly durability properties. In the framework of the feasibility of a reversible conditioning, this document examines first the possible alternative ways of conditioning and storage of calcinates before vitrification, which may simplify the reversibility aspect. Such a conditioning must be compatible with the storage process, with a possible extraction of actinides and long-lived fission products, and with the vitrification process if no extraction is performed. Calcinates are pulverulent and comprise an important soluble fraction, a proportion of nitrates of about 30%, and release a high thermal power (17 kW/m 3 ) combined to a low thermal conductivity (0.1 to 0.15 W.m -1 k -1 ). Among the different foreseeable solutions (denitration, mixing with another material, with or without compacting, dissolution inside another material..), the dissolution inside a borate seems to be the most acceptable with respect to the safety, feasibility and vitrification aspects. The thermal aspect of the storage remains complex as a specific container is necessary. In a second part, this report analyzes the possibility to re-extract back the long-lived radionuclides from vitrified wastes. The different possible ways to destroy the glass structure and to transfer the fission products and minor actinides in an aqueous solution compatible with an hydrometallurgical separation process are explored. Two processes are foreseeable: a low temperature dissolution process which requires a preliminary crushing and the handling of huge amounts of acids, and a both high and low temperature process which comprises the following steps: melting, fractionation by water tempering, addition of Na 2 O or sodium tetraborate to make it sensible to hot leaching, separation of fission products and minor actinides, recycling of

  11. CFD Modelling and Experimental Testing of Thermal Calcination of Kaolinite Rich Clay Particles - An Effort towards Green Concrete

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay

    Cement industry is one of the major industrial emitters of greenhouse gases, generating 5-7% of the total anthropogenic CO2 emissions. Consequently, use of supplementary cementitious materials (SCM) to replace part of the CO2-intensive cement clinker is an attractive way to mitigate CO2 emissions...... from cement industry. SCMs based on industrial byproducts like fly ashes and slags are subject to availability problems. Yet clays are the most ubiquitous material on earth's crust. Thus, properly calcined clays are a very promising candidate for SCMs to produce green cements. Calcination...... property of the calcined clay material, among which is the density of calcines. By using the variation in density of calcines, an optimum residence time has been marked. At this time the calcines display a minimum density that corresponds to the most dehydroxylated calcines. The behavior of flash calcined...

  12. Development of Concentration and Calcination Technology For High Level Liquid Waste

    International Nuclear Information System (INIS)

    Pande, D.P.

    2006-01-01

    The concentrated medium and high-level liquid radio chemicals effluents contain nitric acid, water along with the dissolved chemicals including the nitrates of the radio nuclides. High level liquid waste contain mainly nitrates of cesium, strontium, cerium, zirconium, chromium, barium, calcium, cobalt, copper, pickle, iron etc. and other fission products. This concentrated solution requires further evaporation, dehydration, drying and decomposition in temperature range of 150 to 700 deg. C. The addition of the calcined solids in vitrification pot, instead of liquid feed, helps to avoid low temperature zone because the vaporization of the liquid and decomposition of nitrates do not take place inside the melter. In our work Differential and thermo gravimetric studies has been carried out in the various stages of thermal treatment including drying, dehydration and conversion to oxide forms. Experimental studies were done to characterize the chemicals present in high-level radioactive waste. A Rotary Ball Kiln Calciner was used for development of the process because this is amenable for continuous operation and moderately good heat transfer can be achieved inside the kiln. This also has minimum secondary waste and off gases generation. The Rotary Ball Kiln Calciner Demonstration facility system was designed and installed for the demonstration of calcination process. The Rotary Ball Kiln Calciner is a slowly rotating slightly inclined horizontal tube that is externally heated by means of electric resistance heating. The liquid feed is sprayed onto the moving bed of metal balls in a slowly rotating calciner by a peristaltic type-metering pump. The vaporization of the liquid occurs in the pre-calcination zone due to counter current flow of hot gases. The dehydration and denitration of the solids occurs in the calcination zone, which is externally heated by electrical furnace. The calcined powder is cooled in the post calcination portion. It has been demonstrated that the

  13. Microwave calcination for plutonium immobilization and residue stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Harris, M.J.; Rising, T.L.; Roushey, W.J.; Sprenger, G.S. [Kaiser-Hill Co., Golden, CO (United States)

    1995-12-01

    In the late 1980`s development was begun on a process using microwave energy to vitrify low level mixed waste sludge and transuranic mixed waste sludge generated in Building 374 at Rocky Flats. This process was shown to produce a dense, highly durable waste form. With the cessation of weapons production at Rocky Flats, the emphasis has changed from treatment of low level and TRU wastes to stabilizaiton of plutonium oxide and residues. This equipment is versatile and can be used as a heat source to calcine, react or vitrify many types of residues and oxides. It has natural economies in that it heats only the material to be treated, significantly reducing cycle times over conventional furnaces. It is inexpensive to operate in that most of the working components remain outside of any necessary contamination enclosure and therefore can easily be maintained. Limited testing has been successfully performed on cerium oxide (as a surrogate for plutonium oxide), surrogate electrorefining salts, surrogate residue sludge and residue ash. Future plans also include tests on ion exchange resins. In an attempt to further the usefullness of this technology, a mobile, self-contained microwave melting system is currently under development and expected to be operational at Rocky Flats Enviromental Technology Site by the 4th quarter of FY96.

  14. Microwave calcination for plutonium immobilization and residue stabilization

    International Nuclear Information System (INIS)

    Harris, M.J.; Rising, T.L.; Roushey, W.J.; Sprenger, G.S.

    1995-01-01

    In the late 1980's development was begun on a process using microwave energy to vitrify low level mixed waste sludge and transuranic mixed waste sludge generated in Building 374 at Rocky Flats. This process was shown to produce a dense, highly durable waste form. With the cessation of weapons production at Rocky Flats, the emphasis has changed from treatment of low level and TRU wastes to stabilizaiton of plutonium oxide and residues. This equipment is versatile and can be used as a heat source to calcine, react or vitrify many types of residues and oxides. It has natural economies in that it heats only the material to be treated, significantly reducing cycle times over conventional furnaces. It is inexpensive to operate in that most of the working components remain outside of any necessary contamination enclosure and therefore can easily be maintained. Limited testing has been successfully performed on cerium oxide (as a surrogate for plutonium oxide), surrogate electrorefining salts, surrogate residue sludge and residue ash. Future plans also include tests on ion exchange resins. In an attempt to further the usefullness of this technology, a mobile, self-contained microwave melting system is currently under development and expected to be operational at Rocky Flats Enviromental Technology Site by the 4th quarter of FY96

  15. Calcination/dissolution chemistry development Fiscal year 1995

    International Nuclear Information System (INIS)

    Delegard, C.H.

    1995-09-01

    The task open-quotes IPC Liaison and Chemistry of Thermal Reconstitutionclose quotes is a $300,000 program that was conducted in Fiscal Year (FY) 1995 with U.S. Department of Energy (DOE) Office of Research and Development (EM-53) Efficient Separations and Processing Crosscutting Program supported under technical task plan (TTP) RL4-3-20-04. The principal investigator was Cal Delegard of the Westinghouse Hanford Company (WHC). The task encompassed the following two subtasks related to the chemistry of alkaline Hanford Site tank waste: (1) Technical Liaison with the Institute of Physical Chemistry of the Russian Academy of Science (IPC/RAS) and its research into the chemistry of transuranic elements (TRU) and technetium (Tc) in alkaline media. (2) Laboratory investigation of the chemistry of calcination/dissolution (C/D) (or thermal reconstitution) as an alternative to the present reference Hanford Site tank waste pretreatment flowsheet, Enhanced Sludge Washing (ESW). This report fulfills the milestone for the C/D subtask to open-quotes Provide End-of-Year Report on C/D Laboratory Test Resultsclose quotes due 30 September 1995. A companion report, fulfilling the milestone to provide an end-of-year report on the IPC/RAS liaison, also has been prepared

  16. Pyrochemical separation of radioactive components from inert materials in ICPP high-level calcined waste

    International Nuclear Information System (INIS)

    Del Debbio, J.A.; Nelson, L.O.; Todd, T.A.

    1995-05-01

    Since 1963, calcination of aqueous wastes from reprocessing of DOE-owned spent nuclear fuels has resulted in the accumulation of approximately 3800 m 3 of high-level waste (HLW) at the Idaho Chemical Processing Plant (ICPP). The waste is in the form of a granular solid called calcine and is stored on site in stainless steel bins which are encased in concrete. Due to the leachability of 137 Cs and 90 Sr and possibly other radioactive components, the calcine is not suitable for final disposal. Hence, a process to immobilize calcine in glass is being developed. Since radioactive components represent less than 1 wt % of the calcine, separation of actinides and fission products from inert components is being considered to reduce the volume of HLW requiring final disposal. Current estimates indicate that compared to direct vitrification, a volume reduction factor of 10 could result in significant cost savings. Aqueous processes, which involve calcine dissolution in nitric acid followed by separation of actinide and fission products by solvent extraction and ion exchange methods, are being developed. Pyrochemical separation methods, which generate small volumes of aqueous wastes and do not require calcine dissolution, have been evaluated as alternatives to aqueous processes. This report describes three proposed pyrochemical flowsheets and presents the results of experimental studies conducted to evaluate their feasibility. The information presented is a consolidation of three reports, which should be consulted for experimental details

  17. Calcination of calcium acetate and calcium magnesium acetate: effect of the reacting atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J.; Diego, L.F. de; Garcia-Labiano, F. [Instituto de Carboquimica, Zaragoza (Spain). Dept. of Energy and Environment

    1999-04-01

    The calcination process of the calcium acetate (CA) and calcium magnesium acetate (CMA) was investigated as a previous step for coal gas desulfurisation during sorbent injection at high temperatures because the excellent results demonstrated by these sorbents as sulfur removal agents both in combustion and gasification processes. As pore structure developed during calcination is one of the most important characteristics of the sorbent related with the later reaction with the gaseous pollutants, several calcination tests were conducted in a drop tube reactor at temperatures from 700{degree}C to 1100{degree}C, and residence times from 0.8 to 2.4 s. Four different gas atmospheres were used for comparative purposes: inert, oxidising, reducing, and non-calcining (pure CO{sub 2}). Despite the advantage of the high porous cenospheric structure developed by these sorbents during their injection at high temperature, calcination of the CaCO{sub 3} was not complete even at the longest residence time, 2.4 s, and the highest temperature, 1100{degree}C, tested. An important effect of the reacting atmosphere on the calcination conversion and on the sorbent pore structure was detected. The CO{sub 2} concentration around the particle, both that fed in the reacting gases or that generated by organic material combustion, seems to be responsible for the final calcination conversions obtained in each case, also affecting the sintering suffered by the sorbents. 19 refs., 10 figs.

  18. Stop Smoking—Tube-In-Tube Helical System for Flameless Calcination of Minerals

    Directory of Open Access Journals (Sweden)

    Nils Haneklaus

    2017-11-01

    Full Text Available Mineral calcination worldwide accounts for some 5–10% of all anthropogenic carbon dioxide (CO2 emissions per year. Roughly half of the CO2 released results from burning fossil fuels for heat generation, while the other half is a product of the calcination reaction itself. Traditionally, the fuel combustion process and the calcination reaction take place together to enhance heat transfer. Systems have been proposed that separate fuel combustion and calcination to allow for the sequestration of pure CO2 from the calcination reaction for later storage/use and capture of the combustion gases. This work presents a new tube-in-tube helical system for the calcination of minerals that can use different heat transfer fluids (HTFs, employed or foreseen in concentrated solar power (CSP plants. The system is labeled ‘flameless’ since the HTF can be heated by other means than burning fossil fuels. If CSP or high-temperature nuclear reactors are used, direct CO2 emissions can be divided in half. The technical feasibility of the system has been accessed with a brief parametric study here. The results suggest that the introduced system is technically feasible given the parameters (total heat transfer coefficients, mass- and volume flows, outer tube friction factors, and –Nusselt numbers that are examined. Further experimental work will be required to better understand the performance of the tube-in-tube helical system for the flameless calcination of minerals.

  19. A Summary of Properties Used to Evaluate INEEL Calcine Disposal in the Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Dahl, C.A.

    2003-01-01

    To support evaluations of the direct disposal of Idaho National Engineering and Environmental Laboratory calcines to the repository at Yucca Mountain, an evaluation of the performance of the calcine in the repository environment must be performed. This type of evaluation demonstrates, through computer modeling and analysis, the impact the calcine would have on the ability of the repository to perform its function of containment of materials during the repository lifetime. This report discusses parameters that were used in the scoping evaluation conducted in FY 2003. It provides nominal values for the parameters, with explanation of the source of the values, and how the values were modified for use in repository analysis activities

  20. The effect of calcination conditions on the graphitizability of novel synthetic and coal-derived cokes

    Science.gov (United States)

    Bennett, Barbara Ellen

    The effects of calcination heating rate and ultimate calcination temperature upon calcined coke and subsequent graphitic material microstructures were studied for materials prepared from three different precursors. The pitch precursors used were Mitsubishi AR pitch (a synthetic, 100% mesophase pitch), the NMP-extracted portion of a raw coal, and the NMP-extracted fraction of a coal liquefaction residue obtained from an HTI pilot plant. These materials were all green-coked under identical conditions. Optical microscopy confirmed that the Mitsubishi coke was very anisotropic and the HTI coke was nearly as anisotropic. The coke produced from the direct coal extract was very isotropic. Crystalline development during calcination heating was verified by high-temperature x-ray diffraction. Experiments were performed to ascertain the effects of varying calcination heating rate and ultimate temperature. It was determined that calcined coke crystallite size increased with increasing temperature for all three materials but was found to be independent of heating rate. The graphene interplanar spacing decreased with increasing temperature for the isotropic NMP-extract material but increased with increasing temperature for the anisotropic materials---Mitsubishi and HTI cokes. Graphene interplanar spacing was also found to be independent of heating rate. Calcined coke real densities were, likewise, found to be independent of heating rate. The anisotropic cokes (Mitsubishi and HTI) exhibited increasing real density with increasing calcination temperature. The NMP-extract coke increased in density up to 1050°C and then suffered a dramatic reduction in real density when heated to 1250°C. This is indicative of puffing. Since there was no corresponding disruption in the crystalline structure, the puffing phenomena was determined to be intercrystalline rather than intracrystalline. After the calcined cokes were graphitized (under identical conditions), the microstructures were re

  1. The nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Kurbonov, A.S.; Mamatov, E.D.; Suleymani, M.; Borudzherdi, A.; Mirsaidov, U.M.

    2011-01-01

    Present article is devoted to nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit of Tajikistan. The obtaining of boric acid from pre backed danburite concentrate by decomposition of nitric acid was studied. The chemical composition of danburite concentrate was determined. The laboratory study of danburite leaching by nitric acid was conducted. The influence of temperature, process duration, nitric acid concentration on nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit was studied as well. The optimal conditions of nitric acid decomposition of calcined danburite concentrate of Ak-Arkhar Deposit, including temperature, process duration, nitric acid concentration and particle size were proposed.

  2. Remotely replaceable fuel and feed nozzles for the NWCF calciner vessel

    International Nuclear Information System (INIS)

    Fletcher, R.D.; Carter, J.A.; May, K.W.

    1978-01-01

    The development and testing of remotely replaceable fuel and feed nozzles for calcination of liquid radioactive wastes in the calciner vessel of the New Waste Calcining Facility (NWCF) being built at the Idaho National Engineering Laboratory are described. A complete fuel nozzle assembly was fabricated and tested at the Remote Maintenance Development Facility to evolve design refinements, identify required support equipment, and develop handling techniques. The design also provided for remote replacement of the nozzle support carriage and adjacent feed and fuel pipe loops using two pairs of master-slave manipulators

  3. Calcining natural zeolites to improve their effect on cementitious mixture workability

    International Nuclear Information System (INIS)

    Seraj, Saamiya; Ferron, Raissa D.; Juenger, Maria C.G.

    2016-01-01

    Despite the benefits to long-term concrete durability, the use of natural zeolites as supplementary cementitious materials (SCMs) is uncommon due to their high water demand. The motivation of the research presented here was to better understand how the physical and chemical characteristics of natural zeolites influenced the workability of cementitious mixtures and whether those properties could be modified through calcination to mitigate the high water demand of natural zeolites. In this research, three different natural zeolites were characterized in their original and calcined states using x-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) surface area measurements. Rheology experiments were then conducted on cementitious pastes containing these natural zeolites, in their original and calcined states, to assess mixture viscosity and yield stress. Results showed that calcination destabilized the structure of the natural zeolites and reduced their surface area, which led to an improvement in mixture viscosity and yield stress.

  4. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    KAUST Repository

    Yoon, Seyoon; Moon, Juhyuk; Bae, Sungchul; Duan, Xiaonan; Giannelis, Emmanuel P.; Monteiro, Paulo M.

    2014-01-01

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had

  5. Design criteria for the new waste calcining facility at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Anderson, F.H.; Bingham, G.E.; Buckham, J.A.; Dickey, B.R.; Slansky, C.M.; Wheeler, B.R.

    1976-01-01

    The New Waste Calcining Facility (NWCF) at the Idaho Chemical Processing Plant (ICPP) is being built to replace the existing fluidized-bed, high-level waste calcining facility (WCF). Performance of the WCF is reviewed, equipment failures in WCF operation are examined, and pilot-plant studies on calciner improvements are given in relation to NWCF design. Design features of the NWCF are given with emphasis on process and equipment improvements. A major feature of the NWCF is the use of remote maintenance facilities for equipment with high maintenance requirements, thereby reducing personnel exposures during maintenance and reducing downtime resulting from plant decontamination. The NWCF will have a design net processing rate of 11.36 m 3 of high-level waste per day, and will incorporate in-bed combustion of kerosene for heating the fluidized bed calciner. The off-gas cleaning system will be similar to that for the WCF

  6. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    International Nuclear Information System (INIS)

    COMPTON, J.A.

    2000-01-01

    Stored solutions containing plutonium and nitric acid and possibly uranium thorium and minor amounts of other substances will be used for development and demonstration of a vertical calciner direct denitration process for conversion of those to stable storable PuO 2 rich solids. Some of those solutions are quite dilute and very impure these require either pretreatment to make them suitable for calciner feed or an alternate stabilization method. Untreated scrap solutions containing some amounts of sulfate phosphate sodium and/or potassium may also be tested for suitability of direct denitration for conversion directly to PuO 2 -rich solids. A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium-rich solids. The calciner and some of its ancillary equipment were previously tested with non-radioactive chemicals to demonstrate operability

  7. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    International Nuclear Information System (INIS)

    COMPTON, J.A.

    2000-01-01

    Stored solutions containing plutonium and nitric acid and possibly uranium thorium and minor amounts of other substances will be used for development and demonstration of a vertical calciner direct denitration process for conversion of those to stable storable PuO 2 rich solids. Some of those solutions are quite dilute and very impure these require either pretreatment to make them suitable for calciner feed or an alternate stabilization method. Untreated scrap solutions containing some amounts of sulfate phosphate sodium and/or potassium may also be tested for suitability of direct denitration for conversion directly to PuO 2 -rich solids. A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium rich solids. The calciner and some of its associated equipment were previously tested with non-radioactive chemicals to demonstrate operability

  8. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    Energy Technology Data Exchange (ETDEWEB)

    COMPTON, J.A.

    2000-02-03

    Stored solutions containing plutonium and nitric acid and possibly uranium thorium and minor amounts of other substances will be used for development and demonstration of a vertical calciner direct denitration process for conversion of those to stable storable PuO{sub 2} rich solids. Some of those solutions are quite dilute and very impure these require either pretreatment to make them suitable for calciner feed or an alternate stabilization method. Untreated scrap solutions containing some amounts of sulfate phosphate sodium and/or potassium may also be tested for suitability of direct denitration for conversion directly to PuO{sub 2}-rich solids. A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium-rich solids. The calciner and some of its ancillary equipment were previously tested with non-radioactive chemicals to demonstrate operability.

  9. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    Energy Technology Data Exchange (ETDEWEB)

    COMPTON, J.A.

    2000-02-03

    Stored solutions containing plutonium and nitric acid and possibly uranium thorium and minor amounts of other substances will be used for development and demonstration of a vertical calciner direct denitration process for conversion of those to stable storable PuO{sub 2} rich solids. Some of those solutions are quite dilute and very impure these require either pretreatment to make them suitable for calciner feed or an alternate stabilization method. Untreated scrap solutions containing some amounts of sulfate phosphate sodium and/or potassium may also be tested for suitability of direct denitration for conversion directly to PuO{sub 2}-rich solids. A vertical calciner will be used to demonstrate the direct denitration process for converting plutonium-bearing liquors to stable plutonium rich solids. The calciner and some of its associated equipment were previously tested with non-radioactive chemicals to demonstrate operability.

  10. Decomposition of pre calcined aluminium silicate ores of Afghanistan by hydrochloric acid

    International Nuclear Information System (INIS)

    Khomidi, A.K.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to decomposition of pre calcined aluminium silicate ores of Afghanistan by hydrochloric acid. The physicochemical properties of initial aluminium silicate ores were studied by means of X-ray phase, differential thermal and silicate analysis. The chemical composition of aluminium containing ores was determined. The optimal conditions of interaction of initial and pre calcined siallites with hydrochloric acid were defined. The kinetics of acid decomposition of aluminium silicate ores was studied as well.

  11. Quantitative analysis of calcined fertilizers by X-ray diffraction patterns

    International Nuclear Information System (INIS)

    Cekinski, E.

    1987-01-01

    An X-ray diffraction pattern method for quantitative analyses of phosphate fertilizers obtained by calcination of a misture of Anitapolis phosphate concentrate and sodium carbonate is described. The method consists in plotting a calibration curve, using spinel (MgAl 2 O 4 ) as internal standard, of the phases that were formed by calcination, sintetized in laboratory. The tests conducted in order to avail the method accuracy showed good correlation between the obtained data and the real values. (author) [pt

  12. Formulation Efforts for Direct Vitrification of INEEL Blend Calcine Waste Simulate: Fiscal Year 2000

    Energy Technology Data Exchange (ETDEWEB)

    Crum, Jarrod V.; Vienna, John D.; Peeler, David K.; Reamer, I. A.

    2001-03-30

    This report documents the results of glass formulation efforts for Idaho National Engineering and Environmental Laboratory (INEEL) high level waste (HWL) calcine. Two waste compositions were used during testing. Testing started by using the Run 78 calcine composition and switched to simulated Blend calcine composition when it became available. The goal of the glass formulation efforts was to develop a frit composition that will accept higher waste loading that satisfies the glass processing and product acceptance constraints. 1. Melting temperature of 1125 ? 25?C 2. Viscosity between 2 and 10 Pa?s at the melting temperature 3. Liquidus temperature at least 100?C below the melting temperature 4. Normalized release of B, Li and Na each below 1 g/m2 (per ASTM C 1285-97) Glass formulation efforts tested several frit compositions with variable waste loadings of Run 78 calcine waste simulant. Frit 107 was selected as the primary candidate for processing since it met all process and performance criteria up to 45 mass% waste loading. When the simulated Blend calcine waste composition became available Frits 107 and 108 compositions were retested and again Frit 107 remained the primary candidate. However, both frits suffered a decrease in waste loading when switching from the Run 78 calcine to simulated Blend calcine waste composition. This was due to increase concentrations of both F and Al2O3 along with a decrease in CaO and Na2O in the simulate Blend calcine waste all of which have strong impacts on the glass properties that limit waste loading of this type of waste.

  13. Silicon-Polymer Encapsulation of High-Level Calcine Waste for Transportation or Disposal

    International Nuclear Information System (INIS)

    Loomis, G.G.; Miller, C.M.; Giansiracusa, J.A.; Kimmel, R.; Prewett, S.V.

    2000-01-01

    This report presents the results of an experimental study investigating the potential uses for silicon-polymer encapsulation of High Level Calcine Waste currently stored within the Idaho Nuclear Technology and Engineering Center (INTEC) at the Idaho National Engineering and Environmental Laboratory (INEEL). The study investigated two different applications of silicon polymer encapsulation. One application uses silicon polymer to produce a waste form suitable for disposal at a High Level Radioactive Waste Disposal Facility directly, and the other application encapsulates the calcine material for transportation to an offsite melter for further processing. A simulated waste material from INTEC, called pilot scale calcine, which contained hazardous materials but no radioactive isotopes was used for the study, which was performed at the University of Akron under special arrangement with Orbit Technologies, the originators of the silicon polymer process called Polymer Encapsulation Technology (PET). This document first discusses the PET process, followed by a presentation of past studies involving PET applications to waste problems. Next, the results of an experimental study are presented on encapsulation of the INTEC calcine waste as it applies to transportation or disposal of calcine waste. Results relating to long-term disposal include: (1) a characterization of the pilot calcine waste; (2) Toxicity Characteristic Leaching Procedure (TCLP) testing of an optimum mixture of pilot calcine, polysiloxane and special additives; and, (3) Material Characterization Center testing MCC-1P evaluation of the optimum waste form. Results relating to transportation of the calcine material for a mixture of maximum waste loading include: compressive strength testing, 10-m drop test, melt testing, and a Department of Transportation (DOT) oxidizer test

  14. The leaching of base minerals from the calcines produced by the roasting of pyrite concentrates

    International Nuclear Information System (INIS)

    Nicol, M.J.; Filmer, A.O.

    1985-01-01

    A number of gold and uranium plants in South Africa concentrate the pyrite in the ore residue by flotation and roast the concentrate for the production of sulphuric acid. The calcine produced, which is predominantly hematite, is generally subjected to cyanidation for the recovery of gold and silver. The calcines often contain economically significant quantities of copper, nickel , cobalt and uranium. Prior treatment of the calcine for the recovery of these metals would be desirable in terms of the value of the products. Several processes for the leaching of the base metals from plant calcines have been investigated, and an important general conclusion is that an adequate recovery of the base metals requires that a large proportion of the iron should also be extracted. This observation led to a more extensive investigation of the kinetics of leaching of various iron oxides. The application of electrochemical theory and techniques resulted in a fuller understanding of the various factors that govern the rate of leaching of iron oxides. As a result of this fundamental work, alternative treatment schemes that should yield more efficient extraction from calcines were suggested. Several of these possibilities were investigated, and the most promising were found to require reducing conditions during the leach, or prior partial reduction of the calcine to magnetite or wustite

  15. Origin of Activity and Stability Enhancement for Ag3PO4 Photocatalyst after Calcination

    Directory of Open Access Journals (Sweden)

    Pengyu Dong

    2016-11-01

    Full Text Available Pristine Ag3PO4 microspheres were synthesized by a co-precipitation method, followed by being calcined at different temperatures to obtain a series of calcined Ag3PO4 photocatalysts. This work aims to investigate the origin of activity and stability enhancement for Ag3PO4 photocatalyst after calcination based on the systematical analyses of the structures, morphologies, chemical states of elements, oxygen defects, optical absorption properties, separation and transfer of photogenerated electron-hole pairs, and active species. The results indicate that oxygen vacancies (VO˙˙ are created and metallic silver nanoparticles (Ag NPs are formed by the reaction of partial Ag+ in Ag3PO4 semiconductor with the thermally excited electrons from Ag3PO4 and then deposited on the surface of Ag3PO4 microspheres during the calcination process. Among the calcined Ag3PO4 samples, the Ag3PO4-200 sample exhibits the best photocatalytic activity and greatly enhanced photocatalytic stability for photodegradation of methylene blue (MB solution under visible light irradiation. Oxygen vacancies play a significantly positive role in the enhancement of photocatalytic activity, while metallic Ag has a very important effect on improving the photocatalytic stability. Overall, the present work provides some powerful evidences and a deep understanding on the origin of activity and stability enhancement for the Ag3PO4 photocatalyst after calcination.

  16. Effects of rapid calcination on properties of calcium-based sorbents

    International Nuclear Information System (INIS)

    Yan, Chang-Feng; Grace, John R.; Lim, C. Jim

    2010-01-01

    The calcination process may influence subsequent fragmentation, sintering and swelling when CaO derived from limestone acts as a CO 2 or SO 2 -sorbent in combustion, gasification and reforming. Sorbent properties are affected by CO 2 partial pressure, total pressure, temperature, heating rate, impurities and sample size. In this study, the effect of calcination heating rate was investigated based on an electrically heated platinum foil. The effects of heating rate (up to 800 C/s), calcination temperature (700-950 C), particle size (90-180 μm) and sweep gas velocity were investigated. Higher initial heating rates led to lower extents of limestone calcination, but the extents of carbonation of the resulting CaO were similar to each other. Calcium utilization declined markedly during carbonation or sulphation of CaO after calcination by rapid heating. Experimental results show that carbonation and calcium utilization were most effective for carbonation temperatures between 503 and 607 C. Increasing the extent of calcination is not the best way to improve overall calcium utilization due to the vast increase in energy consumption. (author)

  17. ICPP calcined solids storage facility closure study. Volume III: Engineering design files

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    The following information was calculated to support cost estimates and radiation exposure calculations for closure activities at the Calcined Solids Storage Facility (CSSF). Within the estimate, volumes were calculated to determine the required amount of grout to be used during closure activities. The remaining calcine on the bin walls, supports, piping, and floor was also calculated to approximate the remaining residual calcine volumes at different stages of the removal process. The estimates for remaining calcine and vault void volume are higher than what would actually be experienced in the field, but are necessary for bounding purposes. The residual calcine in the bins may be higher than was is experienced in the field as it was assumed that the entire bin volume is full of calcine before removal activities commence. The vault void volumes are higher as the vault roof beam volumes were neglected. The estimations that follow should be considered rough order of magnitude, due to the time constraints as dictated by the project`s scope of work. Should more accurate numbers be required, a new analysis would be necessary.

  18. Characterization of magnetic biochar amended with silicon dioxide prepared at high temperature calcination

    Directory of Open Access Journals (Sweden)

    Baig Shams Ali

    2016-09-01

    Full Text Available Calcination is considered to increase the hardness of composite material and prevent its breakage for the effective applications in environmental remediation. In this study, magnetic biochar amended with silicon dioxide was calcined at high temperature under nitrogen environment and characterized using various techniques. X-ray diffraction (XRD analysis revealed elimination of Fe3O4 peaks under nitrogen calcination and formation of Fe3Si and iron as major constituents of magnetic biochar-SiO2 composite, which demonstrated its superparamagnetic behavior (>80 A2·kg−1 comparable to magnetic biochar. Thermogravimetric analysis (TGA revealed that both calcined samples generated higher residual mass (>96 % and demonstrated better thermal stability. The presence of various bands in Fourier transform infrared spectroscopy (FT-IR was more obvious and the elimination of H–O–H bonding was observed at high temperature calcination. In addition, scanning electron microscopy (SEM images revealed certain morphological variation among the samples and the presence of more prominent internal and external pores, which then judged the surface area and pore volume of samples. Findings from this study suggests that the selective calcination process could cause useful changes in the material composites and can be effectively employed in environmental remediation measures.

  19. ICPP calcined solids storage facility closure study. Volume III: Engineering design files

    International Nuclear Information System (INIS)

    1998-02-01

    The following information was calculated to support cost estimates and radiation exposure calculations for closure activities at the Calcined Solids Storage Facility (CSSF). Within the estimate, volumes were calculated to determine the required amount of grout to be used during closure activities. The remaining calcine on the bin walls, supports, piping, and floor was also calculated to approximate the remaining residual calcine volumes at different stages of the removal process. The estimates for remaining calcine and vault void volume are higher than what would actually be experienced in the field, but are necessary for bounding purposes. The residual calcine in the bins may be higher than was is experienced in the field as it was assumed that the entire bin volume is full of calcine before removal activities commence. The vault void volumes are higher as the vault roof beam volumes were neglected. The estimations that follow should be considered rough order of magnitude, due to the time constraints as dictated by the project's scope of work. Should more accurate numbers be required, a new analysis would be necessary

  20. Calcination, Reduction and Sintering of ADU Spheres for HTGR Fuel

    International Nuclear Information System (INIS)

    Jeong, Kyung Chai; Eom, Sung Ho; Kim, Yeon Ku; Kim, Woong Ki; Kim, Young Min; Lee, Young Woo; Kim, Ju Hee; Cho, Hyo Jin; Cho, Moon Seoung

    2011-01-01

    formation of spheres is then formed by the dispersed in air and ammonia gases atmosphere. The gelation of polymer was induced at the surface of the droplets in this step. The surfaces of these liquid droplets are slightly solidified by reaction of ammonia gas and uranyl ion into the droplets. Spherical droplets are converted to aged-ADU gels in NH 4 OH solution. Then, many steps, such as the ageing and drying of ADU gel, the calcining to UO 3 , the sintering to UO 2 , were progressed continuously

  1. Design and performance of a full-scale spray calciner for nonradioactive high-level-waste-vitrification studies

    International Nuclear Information System (INIS)

    Miller, F.A.

    1981-06-01

    In the spray calcination process, liquid waste is spray-dried in a heated-wall spray dryer (termed a spray calciner), and then it may be combined in solid form with a glass-forming frit. This mixture is then melted in a continuous ceramic melter or in an in-can melter. Several sizes of spray calciners have been tested at PNL- laboratory scale, pilot scale and full scale. Summarized here is the experience gained during the operation of PNL's full-scale spray calciner, which has solidified approx. 38,000 L of simulated acid wastes and approx. 352,000 L of simulated neutralized wastes in 1830 h of processing time. Operating principles, operating experience, design aspects, and system descriptions of a full-scale spray calciner are discussed. Individual test run summaries are given in Appendix A. Appendices B and C are studies made by Bechtel Inc., under contract by PNL. These studies concern, respectively, feed systems for the spray calciner process and a spray calciner vibration analysis. Appendix D is a detailed structural analysis made at PNL of the spray calciner. These appendices are included in the report to provide a complete description of the spray calciner and to include all major studies made concerning PNL's full-scale spray calciner

  2. Effects of Coke Calcination Level on Pore Structure in Carbon Anodes

    Science.gov (United States)

    Fang, Ning; Xue, Jilai; Lang, Guanghui; Bao, Chongai; Gao, Shoulei

    2016-02-01

    Effects of coke calcination levels on pore structure of carbon anodes have been investigated. Bench anodes were prepared by 3 types of cokes with 4 calcination temperatures (800°C, 900°C, 1000°C and 1100°C). The cokes and anodes were characterized using hydrostatic method, air permeability determination, mercury porosimetry, image analysis and confocal microscopy (CSLM). The cokes with different calcination levels are almost the same in LC values (19-20 Å) and real density (1.967-1.985 g/cm3), while the anode containing coke calcined at 900°C has the lowest open porosity and air permeability. Pore size distribution (represented by Anode H sample) can be roughly divided into two ranges: small and medium pores in diameter of 10-400 μm and large pores of 400-580 μm. For the anode containing coke calcined at 800°C, a number of long, narrow pores in the pore size range of 400-580 μm are presented among cokes particles. Formation of these elongated pores may be attributed to coke shrinkages during the anode baking process, which may develop cracking in the anode under cell operations. More small or medium rounded pores with pore size range of 10-400 μm emerge in the anodes with coke calcination temperatures of 900°C, 1000°C and 1100°C, which may be generated due to release of volatiles from the carbon anode during baking. For the anode containing coke calcined at 1100°C, it is found that many rounded pores often closely surround large coke particles, which have potential to form elongated, narrow pores.

  3. Determination of the Rate of Formation of Hydroceramic Waste Forms made with INEEL Calcined Wastes; FINAL

    International Nuclear Information System (INIS)

    Barry Scheetz; Johnson Olanrewaju

    2001-01-01

    The formulation, synthesis, characterization and hydration kinetics of hydroceramic waste forms designed as potential hosts for existing INEEL calcine high-level wastes have been established as functions of temperature and processing time. Initial experimentations were conducted with several aluminosilicate pozzolanic materials, ranging from fly ash obtained from various power generating coal and other combustion industries to reactive alumina, natural clays and ground bottled glass powders. The final selection criteria were based on the ease of processing, excellent physical properties and chemical durability (low-leaching) determined from the PCT test produced in hydroceramic. The formulation contains vermiculite, Sr(NO32), CsC1, NaOH, thermally altered (calcined natural clay) and INEEL simulated calcine high-level nuclear wastes and 30 weight percent of fluorinel blend calcine and zirconia calcine. Syntheses were carried out at 75-200 degree C at autogeneous water pressure (100% relative humidity) at various time intervals. The resulting monolithic compact products were hard and resisted breaking when dropped from a 5 ft height. Hydroceramic host mixed with fluorinel blend calcine and processed at 75 degree C crumbled into rice hull-side grains or developed scaly flakes. However, the samples equally possessed the same chemical durability as their unbroken counterparts. Phase identification by XRD revealed that hydroceramic host crystallized type zeolite at 75-150 degree C and NaP1 at 175-200 degree C in addition to the presence of quartz phase originating from the clay reactant. Hydroceramic host mixed with either fluorinel blend calcine or zirconia calcine crystallized type A zeolite at 75-95 degree C, formed a mixture of type A zeolite and hydroxysodalite at 125-150 degree C and hydroxysodalite at 175-200 degree C. Quartz, calcium fluoride and zirconia phases from the clay reactant and the two calcine wastes were also detected. The PCT test solution

  4. Determination of the Rate of Formation of Hydroceramic Waste Forms made with INEEL Calcined Wastes

    Energy Technology Data Exchange (ETDEWEB)

    Barry Scheetz; Johnson Olanrewaju

    2001-10-15

    The formulation, synthesis, characterization and hydration kinetics of hydroceramic waste forms designed as potential hosts for existing INEEL calcine high-level wastes have been established as functions of temperature and processing time. Initial experimentations were conducted with several aluminosilicate pozzolanic materials, ranging from fly ash obtained from various power generating coal and other combustion industries to reactive alumina, natural clays and ground bottled glass powders. The final selection criteria were based on the ease of processing, excellent physical properties and chemical durability (low-leaching) determined from the PCT test produced in hydroceramic. The formulation contains vermiculite, Sr(NO32), CsC1, NaOH, thermally altered (calcined natural clay) and INEEL simulated calcine high-level nuclear wastes and 30 weight percent of fluorinel blend calcine and zirconia calcine. Syntheses were carried out at 75-200 degree C at autogeneous water pressure (100% relative humidity) at various time intervals. The resulting monolithic compact products were hard and resisted breaking when dropped from a 5 ft height. Hydroceramic host mixed with fluorinel blend calcine and processed at 75 degree C crumbled into rice hull-side grains or developed scaly flakes. However, the samples equally possessed the same chemical durability as their unbroken counterparts. Phase identification by XRD revealed that hydroceramic host crystallized type zeolite at 75-150 degree C and NaP1 at 175-200 degree C in addition to the presence of quartz phase originating from the clay reactant. Hydroceramic host mixed with either fluorinel blend calcine or zirconia calcine crystallized type A zeolite at 75-95 degree C, formed a mixture of type A zeolite and hydroxysodalite at 125-150 degree C and hydroxysodalite at 175-200 degree C. Quartz, calcium fluoride and zirconia phases from the clay reactant and the two calcine wastes were also detected. The PCT test solution

  5. Spray Calciner/In-Can Melter high-level waste solidification technical manual

    International Nuclear Information System (INIS)

    Larson, D.E.

    1980-09-01

    This technical manual summarizes process and equipment technology developed at Pacific Northwest Laboratory over the last 20 years for vitrification of high-level liquid waste by the Spray Calciner/In-Can Melter process. Pacific Northwest Laboratory experience includes process development and demonstration in laboratory-, pilot-, and full-scale equipment using nonradioactive synthetic wastes. Also, laboratory- and pilot-scale process demonstrations have been conducted using actual high-level radioactive wastes. In the course of process development, more than 26 tonnes of borosilicate glass have been produced in 75 canisters. Four of these canisters contained radioactive waste glass. The associated process and glass chemistry is discussed. Technology areas described include calciner feed treatment and techniques, calcination, vitrification, off-gas treatment, glass containment (the canister), and waste glass chemistry. Areas of optimization and site-specific development that would be needed to adapt this base technology for specific plant application are indicated. A conceptual Spray Calciner/In-Can Melter system design and analyses are provided in the manual to assist prospective users in evaluating the process for plant application, to provide equipment design information, and to supply information for safety analyses and environmental reports. The base (generic) technology for the Spray Calciner/In-Can Melter process has been developed to a point at which it is ready for plant application

  6. Preparation of plutonium waste forms with ICPP calcined high-level waste

    Energy Technology Data Exchange (ETDEWEB)

    Staples, B.A.; Knecht, D.A. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); O`Holleran, T.P. [Argonne National Lab.-West, Idaho Falls, ID (United States)] [and others

    1997-05-01

    Glass and glass-ceramic forms developed for the immobilization of calcined high-level wastes generated by Idaho Chemical Processing Plant (ICPP) fuel reprocessing activities have been investigated for ability to immobilize plutonium and to simultaneously incorporate calcined waste as an anti-proliferation barrier. Within the forms investigated, crystallization of host phases result in an increased loading of plutonium as well as its incorporation into potentially more durable phases than the glass. The host phases were initially formed and characterized with cerium (Ce{sup +4}) as a surrogate for plutonium (Pu{sup +4}) and samarium as a neutron absorber for criticality control. Verification of the surrogate testing results were then performed replacing cerium with plutonium. All testing was performed with surrogate calcined high-level waste. The results of these tests indicated that a potentially useful host phase, based on zirconia, can be formed either by devitrification or solid state reaction in the glass studied. This phase incorporates plutonium as well as samarium and the calcined waste becomes part of the matrix. Its ease of formation makes it potentially useful in excess plutonium dispositioning. Other durable host phases for plutonium and samarium, including zirconolite and zircon have been formed from zirconia or alumina calcine through cold press-sintering techniques and hot isostatic pressing. Host phase formation experiments conducted through vitrification or by cold press-sintering techniques are described and the results discussed. Recommendations are given for future work that extends the results of this study.

  7. Applied laboratory research of high-level waste denitration and calcination technologies

    International Nuclear Information System (INIS)

    Napravnik, J.

    1977-01-01

    Denitration and calcination processes are assessed for model solutions of high-level radioactive wastes. The kinetics was studied of the reaction of HNO 3 with HCOOH with respect to the final composition of the gaseous product. A survey is presented of used denitration agents and of reaction processes. Calcination was studied both as associated with denitration in a single technological step and separately. Also studied was the pyrolysis and chemical decomposition of sodium nitrate which forms an indecomposable melt in the temperature region of 320 to 850 degC under normal conditions. Based on the experiments a laboratory unit was designed and produced for the denitration and calcination of model solutions of high-level radioactive wastes operating in a temperature range of 100 to 550 degC with a capacity of 1000 ml/h. A boiler type stirred evaporator with electric heating (3 kW) was chosen for the denitration unit while a vertical calcinator modified from a film evaporator with a thermal input of 4 kW was chosen for the calcination unit. (B.S.)

  8. Chemistry of proposed calcination/dissolution processing of Hanford Site tank wastes

    International Nuclear Information System (INIS)

    Delegard, C.H.

    1995-01-01

    Plans exist to separate radioactive waste stored in underground tanks at the US Department of Energy's Hanford Site in south central Washington State into low-level and high-level fractions, and to immobilize the separate fractions in high-integrity vitrified forms for long-term disposal. Calcination with water dissolution has been proposed as a possible treatment for achieving low/high-level separation. Chemistry development activities conducted since 1992 with simulated and genuine tank waste show that calcination/dissolution destroys organic carbon and converts nitrate and nitrite to hydroxide and benign offgases. The process also dissolves significant quantities of bulk chemicals (aluminum, chromium, and phosphate), allowing their redistribution from the high-level to the low-level fraction. Present studies of the chemistry of calcination/dissolution processing of genuine wastes, conducted in the period October 1993 to September 1994, show the importance of sodium fluoride phosphate double salt in controlling phosphate dissolution. Peptization of waste solids is of concern if extensive washing occurs. Strongly oxidizing conditions imposed by calcination reactions were found to convert transition metals to soluble anions in the order chromate > manganate > > ferrate. In analogy with manganese behavior, plutonium dissolution, presumably by oxidation to more soluble anionic species, also occurs by calcination/dissolution. Methods to remove plutonium from the product low-level solution stream must be developed

  9. Design of a hot pilot plant facility for demonstration of the pot calcination process

    Energy Technology Data Exchange (ETDEWEB)

    Buckham, J A

    1962-01-01

    A facility was designed for demonstration of the pot calcination process with wastes from processing aluminum alloy fuels, Darex or electrolytic processing of stainless-steel fuels, and Purex processes. This facility will also permit determination of procedures required for economical production of low-porosity, relatively nonleachable materials by addition of suitable reagents to the wastes fed to the calciner. The process consists of concentration by evaporation and thermal decomposition in situ in pots which also serve as the final disposal containers. This unit permits determination of pot loading and density, leachability, melting point, volatile material content, heat release, and thermal conductivity of the calcine. Also to be determined are transient calcine temperature distributions, fission product behavior during calcination, deentrainment obtained in the various parts of the system, decontamination achieved on all liquid and gaseous effluent streams, need for venting of stored pots, optimum means of remotely sealing the pots, and methods required for production of a minimum volume of noncondensable off-gas. This facility will employ nominal full-scale pots 8 and 12 in. in diameter and 8 ft long. A unique evaporator design was evolved to permit operation either with close-coupled continuous feed preparation or with bath feed preparation. Provisions were made to circumvent possible explosions due to organic material in feed solutions and other suspected hazards.

  10. Final safety-analysis report for the Fifth Calcined Solids Storage Facility

    International Nuclear Information System (INIS)

    1982-01-01

    Radioactive aqueous wastes generated by the solvent extraction of uranium from expended fuels at ICPP will be calcined in the New Waste Calcining Facility (NWCF). The calcined solids are pneumatically transferred to stainless steel bins enclosed in concrete vaults for interim storage of up to 500 years. The Fifth Calcined Solids Storage Facility (CSSF) provides 1000 m 3 of storage and consists of seven annular stainless steel bins inside a reinforced concrete vault set on bedrock. Storage of calcined solids is essentially a passive operation with very little opportunity for release of radionuclides and with no potential for criticality. There will be no potential for fire or explosion. Shielding has been designed to assure that the radiation levels at the vault exterior surfaces will be limited to less than 0.5 mRem/h. A sump in the vault floor will collect any in-leakage that may occur. Any water that collects in the sump will be sampled then removed with the sump jet. There will be an extremely small chance of release of radioactive particulates into the atmosphere as a result of a bin leak. The Design Basis Accident (DBA) postulates the spill of solids from an eroded fill line into the vault coupled with a failure of the vault cooling air radiation monitor. For the DBA, the maximum calculated radiation dose to an exposed individual near the site boundary is less than 1.2 μRem to the bone and lung

  11. Removal of Dissolved Silica using Calcinated Hydrotalcite in Real-life Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Sasan, Koroush [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brady, Patrick Vane. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Krumhansl, James L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nenoff, Tina M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sasan, Koroush [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sasan, Koroush [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Water shortages are a growing global problem. Reclamation of industrial and municipal wastewater will be necessary in order to mitigate water scarcity. However, many operational challenges, such as silica scaling, prevent large scale water reuse. Previously, our team at Sandia has demonstrated the use of selective ion exchange materials, such as calcinated hydrotalcite (HTC, (Mg 6 Al 2 (OH) 16 (CO 3 )*4H 2 O)), for the low cost removal of silica from synthetic cooling tower water. However, it is not currently know if calcinated HTC has similar capabilities in realistic applications. The purpose of this study was to investigate the ability of calcinated HTC to remove silica from real cooling tower water. This was investigated under both batch and continuous conditions, and in the presence of competing ions. It was determined that calcinated HTC behaved similarly in real and synthetic cooling tower water; the HTC is highly selective for the silica even in the presence of competing cations. Therefore, the data concludes that calcinated HTC is a viable anti-scaling pretreatment for the reuse of industrial wastewaters.

  12. Preparation of plutonium waste forms with ICPP calcined high-level waste

    International Nuclear Information System (INIS)

    Staples, B.A.; Knecht, D.A.; O'Holleran, T.P.

    1997-05-01

    Glass and glass-ceramic forms developed for the immobilization of calcined high-level wastes generated by Idaho Chemical Processing Plant (ICPP) fuel reprocessing activities have been investigated for ability to immobilize plutonium and to simultaneously incorporate calcined waste as an anti-proliferation barrier. Within the forms investigated, crystallization of host phases result in an increased loading of plutonium as well as its incorporation into potentially more durable phases than the glass. The host phases were initially formed and characterized with cerium (Ce +4 ) as a surrogate for plutonium (Pu +4 ) and samarium as a neutron absorber for criticality control. Verification of the surrogate testing results were then performed replacing cerium with plutonium. All testing was performed with surrogate calcined high-level waste. The results of these tests indicated that a potentially useful host phase, based on zirconia, can be formed either by devitrification or solid state reaction in the glass studied. This phase incorporates plutonium as well as samarium and the calcined waste becomes part of the matrix. Its ease of formation makes it potentially useful in excess plutonium dispositioning. Other durable host phases for plutonium and samarium, including zirconolite and zircon have been formed from zirconia or alumina calcine through cold press-sintering techniques and hot isostatic pressing. Host phase formation experiments conducted through vitrification or by cold press-sintering techniques are described and the results discussed. Recommendations are given for future work that extends the results of this study

  13. RECONSTRUCTION OF CALCINED Zn -Al LAYERED DOUBLE HYDROXIDES DURING TETRACYCLINE ADSORPSION

    Directory of Open Access Journals (Sweden)

    G. M. Starukh

    2015-12-01

    Full Text Available Zn-Al mixed oxides containing ZnO different degree crystallinity were obtained by calcinations of Zn-Al layered double hydroxides (LDHs. The reconstruction of calcined Zn-Al LDHs has been performed under stirring in aqueous suspensions. The assynthesized LDHs, its decomposition products, as well as the reconstructed solids upon hydration were characterized by XRD, N2adsorption, differential and thermal gravimetric analysis. It was found that the ability of Zn-Al LDHs to recover a layered structure under the hydration of mixed oxides depends on the degree of ZnO crystallinity. The partial reconstruction of Zn-Al layered structure occurs in tetracycline solutions irrespective to the degree of ZnO crystallinity in calcined LDHs. Calcined Zn-Al LDHs demonstrate the higher adsorption capacity to tetracycline in comparison with as-prepared Zn-Al LDHs. The adsorption of TC on calcined and uncalcined ZnAl LDHs occurs on the centers of one particular type. It is suggested that surface complexation of the A-ring ligand of TC with Al-OH centers takes place.

  14. Redox calcination study of Synroc D powder containing simulated SRL waste

    International Nuclear Information System (INIS)

    Chen, C.

    1982-01-01

    According to Ringwood [A.E. Ringwood, W. Sinclair, and G.M. McLaughlin, Nuclear Waste Immobilization, Lawrence Livermore Laboratory, Livermore, Rept. UCRL-15147 (1979)], the iron oxidation state is important in controlling, the spinel mineralogy and composition if the amount of titania (TiO 2 ) consumed in spinel formation is to be minimized in favor of the formation of the Synroc phases, zirconolite, perovskite, and nepheline. In our redox calcination studies we observed that the iron oxidation state of FeO/Fe 2 O 3 can be controlled by the redoxcalcining atmosphere. In a CO atmosphere, the oxidation state was reduced to less than 7 wt % Fe 2 O 3 . With appropriate CO 2 /CO gas mixtures the resultant iron oxidation states were in the range of 45 to 59 wt % Fe 2 O 3 . Direct rotary redox calcination of spray dried powder at 600 0 C, without prior air calcination, showed increased redox efficiency when compared to powder that had been previously air calcined at 650 0 C. We believe this is caused by a reduction in particle size. Rotary calcination at 800 0 C in argon has no measurable reduction affect on the iron oxidation state of Synroc D powder

  15. Structural Integrity Program for the Calcined Solids Storage Facilities at the Idaho Nuclear Technology and Engineering Center

    International Nuclear Information System (INIS)

    Bryant, J.W.; Nenni, J.A.

    2003-01-01

    This report documents the activities of the structural integrity program at the Idaho Nuclear Technology and Engineering Center relevant to the high-level waste Calcined Solids Storage Facilities and associated equipment, as required by DOE M 435.1-1, ''Radioactive Waste Management Manual.'' Based on the evaluation documented in this report, the Calcined Solids Storage Facilities are not leaking and are structurally sound for continued service. Recommendations are provided for continued monitoring of the Calcined Solids Storage Facilities

  16. Structural Integrity Program for the Calcined Solids Storage Facilities at the Idaho Nuclear Technology and Engineering Center

    International Nuclear Information System (INIS)

    Jeffrey Bryant

    2008-01-01

    This report documents the activities of the structural integrity program at the Idaho Nuclear Technology and Engineering Center relevant to the high-level waste Calcined Solids Storage Facilities and associated equipment, as required by DOE M 435.1-1, 'Radioactive Waste Management Manual'. Based on the evaluation documented in this report, the Calcined Solids Storage Facilities are not leaking and are structurally sound for continued service. Recommendations are provided for continued monitoring of the Calcined Solids Storage Facilities

  17. Calcination of Fluorinel-sodium waste blends using sugar as a feed additive (formerly WINCO-11879)

    International Nuclear Information System (INIS)

    Newby, B.J.; Thomson, T.D.; O'Brien, B.H.

    1992-06-01

    Methods were studied for using sugar as a feed additive for converting the sodium-bearing wastes stored at the Idaho Chemical Processing Plant into granular, free flowing solids by fluidized-bed calcination at 500 degrees C. All methods studied blended sodium-bearing wastes with Fluorinel wastes but differed in the types of sugar (sucrose or dextrose) that were added to the blend. The most promising sugar additive was determined to be sucrose, since it is converted more completely to inorganic carbon than is dextrose. The effect of the feed aluminum-to-alkali metal mole ratio on calcination of these blends with sugar was also investigated. Increasing the aluminum-to-alkali metal ratio from 0.6 to 1.0 decreased the calcine product-to-fines ratio from 3.0 to 1.0 and the attrition index from 80 to 15%. Further increasing the ratio to 1.25 had no effect

  18. Ce - promoted catalyst from hydrotalcites for CO2 reforming of methane: calcination temperature effect

    Directory of Open Access Journals (Sweden)

    Carlos Enrique Daza

    2012-01-01

    Full Text Available Ce-promoted Ni-catalysts from hydrotalcites were obtained. The effect of calcination temperature on the chemical and physical properties of the catalysts was studied. Several techniques were used to determine the chemical and physical characteristics of oxides. The apparent activation energies of reduction were determined. Catalytic experiments at 48 L g-1h-1 without pre-reduction in CO2 reforming of methane were performed. The spinel-like phase in these oxides was only formed at 1000 ºC. The reduction of Ni2+ in the oxides was clearly affected by the calcination temperature which was correlated with catalytic performance. The catalyst calcined at 700 ºC showed the greatest activity.

  19. Pyrochemical treatment of Idaho Chemical Processing Plant high-level waste calcine

    International Nuclear Information System (INIS)

    Todd, T.A.; DelDebbio, J.A.; Nelson, L.O.; Sharpsten, M.R.

    1993-01-01

    The Idaho Chemical Processing Plant (ICPP), located at the Idaho National Engineering Laboratory (INEL), has reprocessed irradiated nuclear fuels for the US Department of Energy (DOE) since 1951 to recover uranium, krypton-85, and isolated fission products for interim treatment and immobilization. The acidic radioactive high-level liquid waste (HLLW) is routinely stored in stainless steel tanks and then, since 1963, calcined to form a dry granular solid. The resulting high-level waste (HLW) calcine is stored in seismically hardened stainless steel bins that are housed in underground concrete vaults. A research and development program has been established to determine the feasibility of treating ICPP HLW calcine using pyrochemical technology.This technology is described

  20. Stoichiometry of the U3O8 phase formed during calcination of some uranium compounds

    International Nuclear Information System (INIS)

    El-Fekey, S.A.; Farah, M.Y.; Rofail, N.H.

    1981-01-01

    Although recent work has shown U 3 O 8 phase to be the decomposition product obtained after calcining uranyl nitrate, sulphate or ammonium uranate, neither the necessary conditions for obtaining stoichiometric U 3 O 8 nor the details of the reaction have been established. Presence of sulphate or nitrate ions during preparation greatly affects the O/U of the obtained oxides and the physico-chemical properties of uranium tetrafluoride prepared afterwards from it (1-3). The aim of the present investigation was to study the effect of calcination regimes on the stoichiometry of the U 3 O 8 phase produced by the thermal decomposition of uranyl nitrate, sulphate, and ammonium uranate, which was prepared by precipitation from nuclear-pure uranyl sulphate. Stoichiometry of the U 3 O 8 phase formed during calcination of ammonium uranate precipitated from nuclear pure uranyl nitrate solution was reported before (1)

  1. An Assessment of Using Vibrational Compaction of Calcined HLW and LLW in DWPF Canisters

    International Nuclear Information System (INIS)

    Yi, Yun-Bo; Amme, Robert C.; Shayer, Zeev

    2008-01-01

    Since 1963, the INEL has calcined almost 8 million gallons of liquid mixed waste and liquid high-level waste, converting it to some 1.1 million gallons of dry calcine (about 4275.0 m3), which consists of alumina-and zirconia-based calcine and zirconia-sodium blend calcine. In addition, if all existing and projected future liquid wastes are solidified, approximately 2,000 m3 of additional calcine will be produced primarily from sodium-bearing waste. Calcine is a more desirable material to store than liquid radioactive waste because it reduces volume, is much less corrosive, less chemically reactive, less mobile under most conditions, easier to monitor and more protective of human health and the environment. This paper describes the technical issue involved in the development of a feasible solution for further volume reduction of calcined nuclear waste for transportation and long term storage, using a standard DWPF canister. This will be accomplished by developing a process wherein the canisters are transported into a vibrational machine, for further volume reduction by about 35%. The random compaction experiments show that this volume reduction is achievable. The main goal of this paper is to demonstrate through computer modeling that it is feasible to use volume reduction vibrational machine without developing stress/strain forces that will weaken the canister integrity. Specifically, the paper presents preliminary results of the stress/strain analysis of the DWPF canister as a function of granular calcined height during the compaction and verifying that the integrity of the canister is not compromised. This preliminary study will lead to the development of better technology for safe compactions of nuclear waste that will have significant economical impact on nuclear waste storage and treatment. The preliminary results will guide us to find better solutions to the following questions: 1) What are the optimum locations and directions (vertical versus horizontal or

  2. Characterisation of sugar cane straw waste as pozzolanic material for construction: Calcining temperature and kinetic parameters

    International Nuclear Information System (INIS)

    Frias, Moises; Villar-Cocina, E.; Valencia-Morales, E.

    2007-01-01

    This paper reports on the influence of calcining temperature (800 and 1000 deg. C) on the pozzolanic activation of sugar cane straw (SCS). The reaction kinetics of SCS ash-lime mixtures were inferred from physicochemical characteristics (X-ray diffraction patterns and thermogravimetry analysis. The fitting of a kinetic-diffusive model to the experimental data (fixed lime versus time) allowed the computing of the kinetic parameters (reaction rate constant) of the pozzolanic reaction. Results obtained confirm that the sugar cane straw ash (SCSA) calcined at 800 and 1000 deg. C have properties indicative of very high pozzolanic activity. No influence of calcining temperature on the pozzolanic activity was observed. Also, no crystalline compounds during the pozzolanic reaction were identified up to 90 days of reaction. Environmental durability and strength of the consequential mortars remain to be assessed

  3. Synthesis of well-dispersed ZnO nanomaterials by directly calcining zinc stearate

    International Nuclear Information System (INIS)

    Guo Guangsheng; Shi Chen; Tao Dongliang; Qian Weizhong; Han Dongmei

    2009-01-01

    Well-dispersed ZnO nanomaterials were synthesized by direct calcination of zinc stearate. Results from Fourier transform infrared (FT-IR) spectra and X-ray diffraction (XRD) indicated both the decomposition degree of organic ligand and the purity of calcined products were increased with the calcination temperature. The influence of decomposition temperature on the morphology of ZnO nanomaterials was investigated by field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The experimental results revealed the morphology of ZnO transformed from nanosheets to hexagonal nanopyramids and then to nanoparticles at 573, 673 and 773 K respectively. Finally, a morphology evolution model of ZnO nanomaterials under different temperatures was proposed

  4. Calcinated tea and cellulose composite films and its dielectric and lead adsorption properties.

    Science.gov (United States)

    Jayaramudu, Tippabattini; Varaprasad, Kokkarachedu; Kim, Hyun Chan; Kafy, Abdullahil; Kim, Jung Woong; Kim, Jaehwan

    2017-09-01

    In this paper, calcinated tea and cellulose composite (CTCC) films were fabricated via solution casting method. Chemical structure, morphology, crystallinity and thermal stability of the fabricated films were characterized by using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction and thermogravimetric analysis. The effect of calcinated tea loading on the properties of the prepared CTCC films was studied. The results suggest that the prepared CTCC films show higher mechanical properties, thermal stability and dielectric constant than the neat cellulose film. In addition, the CTCC films adsorb Pb 2+ ions and its adsorption performance depends on the calcinated tea content and pH level. The CTCC films are useful for sensors, flexible capacitor as well as lead adsorption applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Biodiesel production from waste cooking oil using calcined scallop shell as catalyst

    International Nuclear Information System (INIS)

    Sirisomboonchai, Suchada; Abuduwayiti, Maidinamu; Guan, Guoqing; Samart, Chanatip; Abliz, Shawket; Hao, Xiaogang; Kusakabe, Katsuki; Abudula, Abuliti

    2015-01-01

    Highlights: • Calcined scallop shell was used as low-cost and effective catalyst for biodiesel production. • BDF yield from waste cooking oil reached 86% at 65 °C with a catalyst loading amount of 5 wt%. • Calcined scallop shell showed good reusability. • Calcium glyceroxide played an important role on the reusability of calcined scallop shell. • Water in the waste cooking oil had negative effect on the catalytic activity of calcined scallop shell. - Abstract: Transesterification of waste cooking oil (WCO) and methanol by using calcined scallop shell (CSS) as catalyst was carried out in a closed system for biodiesel fuel (BDF) production. It is found that the optimum calcination temperature for the preparation of CSS was 1000 °C. The effects of transesterification temperature, reaction time, methanol/oil molar ratio and catalyst loading amount on the BDF yield were investigated. Compared with the commercial CaO, CSS showed higher catalytic activity and the BDF yield reached 86% at 65 °C with a catalyst loading amount of 5 wt% (WCO basis) and a reaction time of 2 h. The catalyst was reused for 5 cycles whilst the BDF yield decreased 23%. It is found that CaO in CSS was transferred to calcium glyceroxide after the transesterification reaction, and calcium glyceroxide also showed good catalytic activity and reusability. Furthermore, Water content in WCO had negative effect on BDF yield. It is found that BDF yield reduced 15% due to the occurring of saponification when the water content was increased from 0.64% to 2.48%. It is expected that CCS can be used as an alternative and cheap catalyst for the biodiesel production

  6. Study of variation grain size in desulfurization process of calcined petroleum coke

    Science.gov (United States)

    Pintowantoro, Sungging; Setiawan, Muhammad Arif; Abdul, Fakhreza

    2018-04-01

    Indonesia is a country with abundant natural resources, such as mineral mining and petroleum. In petroleum processing, crude oil can be processed into a source of fuel energy such as gasoline, diesel, oil, petroleum coke, and others. One of crude oil potentials in Indonesia is petroleum coke. Petroleum coke is a product from oil refining process. Sulfur reducing process in calcined petroleum cokes can be done by desulfurization process. The industries which have potential to become petroleum coke processing consumers are industries of aluminum smelting (anode, graphite block, carbon mortar), iron riser, calcined coke, foundry coke, etc. Sulfur reducing process in calcined petroleum coke can be done by thermal desulfurization process with alkaline substance NaOH. Desulfurization of petroleum coke process can be done in two ways, which are thermal desulfurization and hydrodesulphurization. This study aims to determine the effect of various grain size on sulfur, carbon, and chemical bond which contained by calcined petroleum coke. The raw material use calcined petroleum coke with 0.653% sulfur content. The grain size that used in this research is 50 mesh, then varied to 20 mesh and 100 mesh for each desulfurization process. Desulfurization are tested by ICP, UV-VIS, and FTIR to determine levels of sulfur, carbon, chemical bonding and sulfur dissolved water which contained in the residual washing of calcined petroleum coke. From various grain size that mentioned before, the optimal value is on 100 mesh grain size, where the sulfur content in petroleum coke is 0.24% and carbon content reaches the highest level of 97.8%. Meanwhile for grain size 100 mesh in the desulfurization process is enough to break the chemical bonds of organic sulfur in petroleum coke.

  7. Volatilisation of ruthenium in vitrification. Isothermal calcination studies of 'Magnox' and thermal oxide simulates

    International Nuclear Information System (INIS)

    Cains, P.W.; Hay, D.A.

    1982-12-01

    Ru volatilities have been measured for the static, isothermal calcination of ''Magnox'' and Thermal Oxide HAL's (Highly Active Liquors) at temperatures up to 600 0 C. Model solutions containing Ru, HNO 3 , and nitrates of important individual cations have also been investigated. Experimental design was primarily based on the requirements of rotary calcination process development. The results have been interpreted in terms of a reaction model involving competition between the simple degradation of Ru(NO) complexes to RuO 2 and oxidative decomposition to volatile species (e.g. RuO 4 ). (author)

  8. ICPP radioactive liquid and calcine waste technologies evaluation final report and recommendation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-04-01

    Using a formalized Systems Engineering approach, the Latched Idaho Technologies Company developed and evaluated numerous alternatives for treating, immobilizing, and disposing of radioactive liquid and calcine wastes at the Idaho Chemical Processing Plant. Based on technical analysis data as of March, 1995, it is recommended that the Department of Energy consider a phased processing approach -- utilizing Radionuclide Partitioning for radioactive liquid and calcine waste treatment, FUETAP Grout for low-activity waste immobilization, and Glass (Vitrification) for high-activity waste immobilization -- as the preferred treatment and immobilization alternative.

  9. Microwave energy for post-calcination treatment of high-level nuclear wastes

    International Nuclear Information System (INIS)

    Gombert, D.; Priebe, S.J.; Berreth, J.R.

    1980-01-01

    High-level radioactive wastes generated from nuclear fuel reprocessing require treatment for effective long-term storage. Heating by microwave energy is explored in processing of two possible waste forms: (1) drying of a pelleted form of calcined waste; and (2) vitrification of calcined waste. It is shown that residence times for these processes can be greatly reduced when using microwave energy rather than conventional heating sources, without affecting product properties. Compounds in the waste and in the glass frit additives couple very well with the 2.45 GHz microwave field so that no special microwave absorbers are necessary

  10. Talc-silicon glass-ceramic waste forms for immobilization of high- level calcined waste

    International Nuclear Information System (INIS)

    Vinjamuri, K.

    1993-06-01

    Talc-silicon glass-ceramic waste forms are being evaluated as candidates for immobilization of the high level calcined waste stored onsite at the Idaho Chemical Processing Plant. These glass-ceramic waste forms were prepared by hot isostatically pressing a mixture of simulated nonradioactive high level calcined waste, talc, silicon and aluminum metal additives. The waste forms were characterized for density, chemical durability, and glass and crystalline phase compositions. The results indicate improved density and chemical durability as the silicon content is increased

  11. Volatilization and trapping of ruthenium during calcination of nitric acid solutions

    International Nuclear Information System (INIS)

    Klein, M.; Weyers, C.; Goossens, W.R.A.; Smet, M. de; Trine, J.

    1983-01-01

    Solid radioactive aerosols and semi-volatile fission products e.g. Ru, Cs, Sb are generated during high level liquid waste calcination and vitrification processes. The retention of Ruthenium was studied because of its strong tendency to form volatile compounds in oxidative media. Since RuO 4 was the suspected form for high temperature processes, the study was carried out on the behaviour of RuO 4 and its retention on adsorbants and catalysts for various gas compositions. The behaviour of volatilized Ru species obtained by calcination of nitrosyl Ru compounds was then compared with the RuO 4 case

  12. Fuzzy modeling and control of the calcination process in a kiln

    International Nuclear Information System (INIS)

    Ramirez, M.; Haber, R.

    1999-01-01

    Calcination kilns are strongly nonlinear, multivariable processes, that only can be modeled with great uncertainty. In order to get a quality product and ensure the process efficiency, the controller must keep a prescribed temperature profile optimizing the fuel consumption. In this paper, a design methodology of a multivariable fuzzy controller for a nickel calcination kiln is presented. The controller structure is a classical one, and uses the Mamdani fuzzy inference system. In simulation results the fuzzy controller exhibits a great robustness in presence of several types of disturbances, and a better performance than the PID in same conditions is observed. (author)

  13. Use of calcination in exposing the entrapped Fe particles from multi-walled carbon nanotubes grown by chemical vapour deposition

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2009-03-01

    Full Text Available behaviour of the as-prepared and calcined samples was investigated by thermogravimetric analysis. Calcination in air, at 400°C for 1 h, was found to be an efficient and simple method to extract metallic impurities from the amorphous carbon shells...

  14. Effect of the rate of calcination of kaolin on the properties of metakaolin-based geopolymers

    Directory of Open Access Journals (Sweden)

    B.B. Kenne Diffo

    2015-03-01

    Full Text Available Kaolin samples of the same mass were treated at 700 °C for the same duration of 30 min by varying the rate of calcination (1, 2.5, 5, 10, 15 and 20 °C/min in order to obtain metakaolins which were used to produce geopolymers. Depending on the nature of each type of material, kaolin, metakaolins and geopolymers were characterized using thermal analysis, chemical analysis, XRD, FTIR, particle size distribution, specific surface area, bulk density, setting time and compressive strength. FTIR and XRD analyses showed that metakaolins except at 1 °C/min contained residual kaolinite whose quantity increased with the rate of calcination of kaolin and which influenced the characteristics of geopolymers. Thus as the rate of calcination of kaolin increased, the setting time increased (226 min (rate of 1 °C/min–773 min (rate of 20 °C/min while the compressive strength reduced (49.4 MPa (rate of 1 °C/min–20.8 MPa (rate of 20 °C/min. From the obtained results the production of geopolymers having high compressive strength along with low setting time requires that the calcination of kaolin be carried out at a low rate.

  15. Influence of calcined mud on the mechanical properties and shrinkage of self-compacting concrete

    Directory of Open Access Journals (Sweden)

    Fatima Taieb

    2018-01-01

    Full Text Available The use of SCC has a particular interest in terms of sustainable development. Indeed, their specific formulation leads to a greater volume of dough than for common concretes, thus, a larger quantity of cement. However, for economical, ecological and technical reasons, it is sought to limit their cement content [1]. It is therefore necessary to almost always use mineral additions as a partial replacement for cement because the technology of self-compacting concretes can consume large quantities of fines, in this case calcinated mud issued from dams dredging sediments that can give and/or ameliorate characteristics and performances of this type of concretes. Four SCCs had been formulated from the same composition where the only percentage of calcinated mud of Chorfa (west of Algeria dam changed (0%, 10%, 20% and 30%. The effect of calcinated mud on characteristics at fresh state of SCC according to AFGC was quantified. Mechanical strengths and shrinkage deformation (total, autogenous, drying were evaluated. The results show the possibility to make SCCs with different dosages of calcinated mud having strengths that can defy those of the control SCC. The analysis of free deformations indicates the beneficial impact of the mud by contributing to decrease the amplitudes of the shrinkage compared to those of the control SCC.

  16. Restart Plan for the Prototype Vertical Denitration Calciner [SD Coversheet has Incorrect Document Number

    Energy Technology Data Exchange (ETDEWEB)

    SUTTER, C.S.

    1999-07-26

    Testing activities on the Prototype Vertical Denitration Calciner at PFP were suspended in January 1997 due to the hold on fissile material handling in the facility. The Restart Plan will govern the transition of the test program from the completion of the activity based startup review; through equipment checkout and surrogate material runs; to resumption of the testing program and transition to unrestricted testing.

  17. Phosphorous removal from aqueous solution can be enhanced through the calcination of lime sludge.

    Science.gov (United States)

    Bal Krishna, K C; Niaz, Mohamed R; Sarker, Dipok C; Jansen, Troy

    2017-09-15

    Water treatment plants generate an enormous amount of the sludge which is normally treated as waste. In the recent past, many investigations have been focused on developing an economical adsorbent using water treatment sludge to remove phosphorous (P) from aqueous solutions. However, the great extents of the studies have been limited in the use of alum- and iron-based sludges. This study, therefore, investigated the P removal performance of the calcined lime sludge. Calcined lime sludge at 700 °C significantly enhanced the P removal efficiency whereas marginal improvement was noted when the sludge calcined at 400 °C was tested. With increase P removal efficiency, final pH values of the solution also significantly increased. P removal efficiency of the calcined sludge decreased with increasing the initial P concentrations. However, the removal efficiency could be improved by increasing the weight of the sludge. Further analysis demonstrated that P removal trend followed both pseudo-second order and diffusion-chemisorption kinetics signifying the P removal is potentially due to a multi-mechanistic reaction in which, the process is controlled by intra-particle diffusion followed by chemisorptions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Sorption-desorption of antimony species onto calcined hydrotalcite: Surface structure and control of competitive anions.

    Science.gov (United States)

    Constantino, Leonel Vinicius; Quirino, Juliana Nunes; Abrão, Taufik; Parreira, Paulo Sérgio; Urbano, Alexandre; Santos, Maria Josefa

    2018-02-15

    Calcined hydrotalcite can be applied to remove anionic contaminants from aqueous systems such as antimony species due to its great anion exchange capacity and high surface area. Hence, this study evaluated antimonite and antimonate sorption-desorption processes onto calcined hydrotalcite in the presence of nitrate, sulfate and phosphate. Sorption and desorption experiments of antimonite and antimonate were carried out in batch equilibrium and the post-sorption solids were analyzed by X-ray fluorescence (EDXRF). Sorption data were better fitted by dual-mode Langmuir-Freundlich model (R 2 >0.99) and desorption data by Langmuir model. High maximum sorption capacities were found for the calcined hydrotalcite, ranging from 617 to 790meqkg -1 . The competing anions strongly affected the antimony sorption. EDXRF analysis and mathematical modelling showed that sulfate and phosphate presented higher effect on antimonite and antimonate sorption, respectively. High values for sorption efficiency (SE=99%) and sorption capacity were attributed to the sorbent small particles and the large surface area. Positive hysteresis indexes and low mobilization factors (MF>3%) suggest very low desorption capacity to antimony species from LDH. These calcined hydrotalcite characteristics are desirable for sorption of antimony species from aqueous solutions. Copyright © 2017. Published by Elsevier B.V.

  19. CO{sub 2} capture behavior of shell during calcination/carbonation cycles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.J.; Zhao, C.S.; Chen, H.C.; Duan, L.B.; Chen, X.P. [School of Energy and Environment, Southeast University, Nanjing (China)

    2009-08-15

    The cyclic carbonation performances of shells as CO{sub 2} sorbents were investigated during multiple calcination/carbonation cycles. The carbonation kinetics of the shell and limestone are similar since they both exhibit a fast kinetically controlled reaction regime and a diffusion controlled reaction regime, but their carbonation rates differ between these two regions. Shell achieves the maximum carbonation conversion for carbonation at 680-700 C. The mactra veneriformis shell and mussel shell exhibit higher carbonation conversions than limestone after several cycles at the same reaction conditions. The carbonation conversion of scallop shell is slightly higher than that of limestone after a series of cycles. The calcined shell appears more porous than calcined limestone, and possesses more pores >230 nm, which allow large CO{sub 2} diffusion-carbonation reaction rates and higher conversion due to the increased surface area of the shell. The pores of the shell that are greater than 230 nm do not sinter significantly. The shell has more sodium ions than limestone, which probably leads to an improvement in the cyclic carbonation performance during the multiple calcination/carbonation cycles. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  20. Studies on the calcination of ammonium uranates with special reference to density

    International Nuclear Information System (INIS)

    El-Fekey, S.A.; Rofail, N.H.; Farah, M.Y.

    1980-01-01

    The objective of this study was to throw some light on ammonium uranates precipitated from uranyl nitrate solution using ammonia or urea. The effect of washing the uranates, thickness of their layers on the trays during subsequent calcination, temperature and duration, on the densities of powders formed during thermal decomposition was studied. (author)

  1. Synthesis of alumina powder with seeds by Pechini Method using O2 as calcination atmosphere

    International Nuclear Information System (INIS)

    Salem, R.E.P.; Guilherme, K.A.; Chinelatto, A.S.A.; Chinelatto, A. L.

    2012-01-01

    Alumina is a very investigated material due to its excellent refractory characteristics and mechanical properties. Its alpha phase, the most stable one, has a formation temperature of about 1200 ° C. Due to its high temperature of formation, many researches have been trying to reduce it through addition of seeds of alpha phase in chemical processes of synthesis. This work aims to synthesize ultrafine powders of alpha-alumina by the Pechini method with seeding, and using an O 2 atmosphere in the pre-calcination (500 ° C) and calcination (1000 ° C and 1100° C) steps. The resulting powders were characterized through X-ray diffractometry, infrared spectroscopy and scanning electron microscopy. The results were compared with samples calcined on ai. It was verified that the presence of oxygen in the calcination atmosphere favored the elimination of residual carbon from the precursor powders, forthcoming from the great amount of organic material used on the synthesis, modifying its morphology and favoring reduction of particle size. (author)

  2. Method and apparatus for evaporating radioactive liquid and calcinating the residue

    International Nuclear Information System (INIS)

    Sridhar, T.S.

    1984-01-01

    This invention provides an apparatus and a process for evaporating liquid wastes and calcining the residue. The liquid is sprayed against a hollow, rotating heated cylinder within a casing. The dried residue is scraped from the rotating cylinder and released through a valve at the bottom of the casing, while the effluent gas is filtered

  3. Physical, morphological and rheological alterations of properties by the calcination of aluminium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Pandolfelli, V C; Varela, J A; Longo, E

    1987-03-01

    Evolution of physical, morphological and rheological characteristics resulted from several thermal treatments on national aluminium hydroxide, are evaluated and discussed after mercury porosimetry analysis, scanning electron microscopy, surface area and pressure curve compaction. The results may consider about the Kinetics of the reaction during the aglomerate calcination and to verify the better processing conditions to get products with superior performance. (Autor).

  4. Measurement of the loss on ignition of bulk calcined bauxite samples by neutron moderation

    International Nuclear Information System (INIS)

    Aylmer, J.A.; Borsaru, M.

    1985-01-01

    The production of high-grade calcined bauxite is very dependent on the moisture content of the final product. Existing procedures rely on the ignition of small samples to monitor the effectiveness of the calcination process. The results obtained by this gravimetric technique are several hours behind production and do not permit regular adjustment of the furnace to optimize the control of the chemically bound water content (LOI). To provide rapid and more relevant results, a neutron moderation technique has been developed for measuring the LOI of bulk samples of calcined bauxite while they are still hot. The method uses fast neutrons from an 241 Am-Be neutron source to irradiate the samples, and the backscattered thermal neutrons detected are a measure of bound moisture content. The rms deviation between neutron and conventional determinations of LOI, in 15 calcined bauxite samples, was 0.08 per cent LOI over the range 0.1 to 0.9 per cent LOI. When allowance is made for the rms error in the ignition method, the error in the neutron method is found to be 0.07 per cent LOI

  5. 46 CFR 148.04-15 - Petroleum coke, uncalcined; petroleum coke, uncalcined and calcined (mixture).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Petroleum coke, uncalcined; petroleum coke, uncalcined and calcined (mixture). 148.04-15 Section 148.04-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... Requirements for Certain Material § 148.04-15 Petroleum coke, uncalcined; petroleum coke, uncalcined and...

  6. Design and performance of atomizing nozzles for spray calcination of high-level wastes

    International Nuclear Information System (INIS)

    Miller, F.A.; Stout, L.A.

    1981-05-01

    A key aspect of high-level liquid-waste spray calcination is waste-feed atomization by using air atomizing nozzles. Atomization substantially increases the heat transfer area of the waste solution, which enhances rapid drying. Experience from the spray-calciner operations has demonstrated that nozzle flow conditions that produce 70-μ median-volume-diameter or smaller spray droplets are required for small-scale spray calciners (drying capacity less than 80 L/h). For large-scale calciners (drying capacity greater than 300 L/h), nozzle flow conditions that produce 100-μ median-volume-diameter or smaller spray droplets are required. Mass flow ratios of 0.2 to 0.4, depending on nozzle size, are required for proper operation of internal-mix atomizing nozzles. Both internal-mix and external-mix nozzles have been tested at PNL. Due to the lower airflow requirements and fewer large droplets produced, the internal-mix nozzle has been chosen for primary development in the spray calciner program at PNL. Several nozzle air-cap materials for internal-mix nozzles have been tested for wear resistance. Results show that nozzle air caps of stainless steel and Cer-vit (a machineable glass ceramic) are suceptible to rapid wear by abrasive slurries, whereas air caps of alumina and reaction-bonded silicon nitride show only slow wear. Longer-term testing is necessary to determine more accurately the actual frequency of nozzle replacement. Atomizing nozzle air caps of alumina are subject to fracture from thermal shock, whereas air caps of silicon nitride and Cer-vit are not. Fractured nozzles are held in place by the air-cap retaining ring and continue to atomize satisfactorily. Therefore, fractures caused by thermal shocking do not necessarily result in nozzle failure

  7. Effect of calcination temperature on microstructure and electrochemical performance of lithium-rich layered oxide cathode materials

    International Nuclear Information System (INIS)

    Ma, Quanxin; Peng, Fangwei; Li, Ruhong; Yin, Shibo; Dai, Changsong

    2016-01-01

    Highlights: • A series of Li-rich layered oxide cathode materials (Li_1_._2Mn_0_._5_6Ni_0_._1_6Co_0_._0_8O_2) were successfully synthesized via a two-step synthesis method. • The effects of calcination temperature on the cathode materials were researched in detail. • A well-crystallized layered structure was obtained as the calcination temperature increased. • The samples calcined in a range of 850–900 °C exhibited excellent electrochemical performance. - Abstract: Lithium-rich layered oxide cathode materials (Li_1_._2Mn_0_._5_6Ni_0_._1_6Co_0_._0_8O_2 (LLMO)) were synthesized via a two-step synthesis method involving co-precipitation and high-temperature calcination. The effects of calcination temperature on the cathode materials were studied in detail. Structural and morphological characterizations revealed that a well-crystallized layered structure was obtained at a higher calcination temperature. Electrochemical performance evaluation revealed that a cathode material obtained at a calcination temperature of 850 °C delivered a high initial discharge capacity of 266.8 mAh g"−"1 at a 0.1 C rate and a capacity retention rate of 95.8% after 100 cycles as well as excellent rate capability. Another sample calcinated at 900 °C exhibited good cycling stability. It is concluded that the structural stability and electrochemical performance of Li-rich layered oxide cathode materials were strongly dependent on calcination temperatures. The results suggest that a calcination temperature in a range of 850–900 °C could promote electrochemical performance of this type of cathode materials.

  8. Effect of calcination temperature on microstructure and electrochemical performance of lithium-rich layered oxide cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Quanxin; Peng, Fangwei; Li, Ruhong; Yin, Shibo; Dai, Changsong, E-mail: changsd@hit.edu.cn

    2016-11-15

    Highlights: • A series of Li-rich layered oxide cathode materials (Li{sub 1.2}Mn{sub 0.56}Ni{sub 0.16}Co{sub 0.08}O{sub 2}) were successfully synthesized via a two-step synthesis method. • The effects of calcination temperature on the cathode materials were researched in detail. • A well-crystallized layered structure was obtained as the calcination temperature increased. • The samples calcined in a range of 850–900 °C exhibited excellent electrochemical performance. - Abstract: Lithium-rich layered oxide cathode materials (Li{sub 1.2}Mn{sub 0.56}Ni{sub 0.16}Co{sub 0.08}O{sub 2} (LLMO)) were synthesized via a two-step synthesis method involving co-precipitation and high-temperature calcination. The effects of calcination temperature on the cathode materials were studied in detail. Structural and morphological characterizations revealed that a well-crystallized layered structure was obtained at a higher calcination temperature. Electrochemical performance evaluation revealed that a cathode material obtained at a calcination temperature of 850 °C delivered a high initial discharge capacity of 266.8 mAh g{sup −1} at a 0.1 C rate and a capacity retention rate of 95.8% after 100 cycles as well as excellent rate capability. Another sample calcinated at 900 °C exhibited good cycling stability. It is concluded that the structural stability and electrochemical performance of Li-rich layered oxide cathode materials were strongly dependent on calcination temperatures. The results suggest that a calcination temperature in a range of 850–900 °C could promote electrochemical performance of this type of cathode materials.

  9. Fluidized-bed calcination of LWR fuel-reprocessing HLLW: requirements and potential for off-gas cleanup

    International Nuclear Information System (INIS)

    Schindler, R.E.

    1979-01-01

    Fluidized-bed solidification (calcination) was developed on a pilot scale for a variety of simulated LWR high-level liquid-waste (HLLW) and blended high-level and intermediate-level liquid-waste (ILLW) compositions. It has also been demonstrated with ICPP fuel-reprocessing waste since 1963 in the Waste Calcining Facility (WCF) at gross feed rates of 5 to 12 m 3 /day. A fluidized-bed calciner produces a relatively large volume of off-gas. A calciner solidifying 6 m 3 /day of liquid waste would generate about 13 standard m 3 /min of off-gas containing 10 to 20 g of entrained solids per standard m 3 of off-gas. Use of an off-gas system similar to that of the WCF could provide an overall process decontamination factor for particulates of about 2 x 10 10 . A potential advantage of fluidized-bed calcination over other solidification methods is the ability to control ruthenium volatilization from the calciner at less than 0.01% by calcining at 500 0 C or above. Use of an off-gas system similar to that of the WCF would provide an overall process decontamination factor for volatile ruthenium of greater than 1.6 x 10 7

  10. The variation of cationic microstructure in Mn-doped spinel ferrite during calcination and its effect on formaldehyde catalytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Xiaoliang [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640 (China); Liu, Peng [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640 (China); He, Hongping, E-mail: hehp@gig.ac.cn [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640 (China); Wei, Gaoling [Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Chen, Tianhu [School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009 (China); Tan, Wei; Tan, Fuding [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640 (China); Zhu, Jianxi; Zhu, Runliang [CAS Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Guangdong Provincial Key Laboratory of Mineral Physics and Materials, Guangzhou 510640 (China)

    2016-04-05

    Highlights: • Calcination causes the activity variation of Mn-doped ferrites for HCHO oxidation. • The variation of catalytic activity of ferrites by calcination is non-linear. • Mn enriches on the calcinated ferrite surface in the valence of +3 and +4. • The reduction temperature of surface Mn{sup 4+} species is well correlated to T50. - Abstract: In this study, a series of Mn substituted spinel ferrites calcinated at different temperatures were used as catalysts for the oxidation of formaldehyde (HCHO). X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and H{sub 2} temperature-programmed reduction were conducted to characterize the structure and physico-chemical properties of catalysts, which were affected by calcination in the range of 200–600 °C. Results show that all the ferrites were with spinel structure, and those calcinated in the range of 300–600 °C were in the phase of maghemite. The calcination changed the valence and distribution of Mn and Fe on the ferrite surface, and accordingly the reducibility of ferrites. The HCHO catalytic oxidation test showed that with the increase of calcination temperature, the activity was initially improved until 400 °C, but then decreased. The variation of HCHO conversion performance was well positively correlated to the variation of reduction temperature of surface Mn{sup 4+} species. The remarkable effect of calcination on the catalytic activity of Mn-doped spinel ferrites for HCHO oxidation was discussed in view of reaction mechanism and variations in cationic microstructure of Mn-doped ferrites.

  11. The variation of cationic microstructure in Mn-doped spinel ferrite during calcination and its effect on formaldehyde catalytic oxidation

    International Nuclear Information System (INIS)

    Liang, Xiaoliang; Liu, Peng; He, Hongping; Wei, Gaoling; Chen, Tianhu; Tan, Wei; Tan, Fuding; Zhu, Jianxi; Zhu, Runliang

    2016-01-01

    Highlights: • Calcination causes the activity variation of Mn-doped ferrites for HCHO oxidation. • The variation of catalytic activity of ferrites by calcination is non-linear. • Mn enriches on the calcinated ferrite surface in the valence of +3 and +4. • The reduction temperature of surface Mn"4"+ species is well correlated to T50. - Abstract: In this study, a series of Mn substituted spinel ferrites calcinated at different temperatures were used as catalysts for the oxidation of formaldehyde (HCHO). X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and H_2 temperature-programmed reduction were conducted to characterize the structure and physico-chemical properties of catalysts, which were affected by calcination in the range of 200–600 °C. Results show that all the ferrites were with spinel structure, and those calcinated in the range of 300–600 °C were in the phase of maghemite. The calcination changed the valence and distribution of Mn and Fe on the ferrite surface, and accordingly the reducibility of ferrites. The HCHO catalytic oxidation test showed that with the increase of calcination temperature, the activity was initially improved until 400 °C, but then decreased. The variation of HCHO conversion performance was well positively correlated to the variation of reduction temperature of surface Mn"4"+ species. The remarkable effect of calcination on the catalytic activity of Mn-doped spinel ferrites for HCHO oxidation was discussed in view of reaction mechanism and variations in cationic microstructure of Mn-doped ferrites.

  12. High-Temperature Release of SO2 from Calcined Cement Raw Materials

    DEFF Research Database (Denmark)

    Nielsen, Anders Rooma; Larsen, Morten B.; Glarborg, Peter

    2011-01-01

    During combustion of alternative fuels in the material inlet end of cement rotary kilns, local reducing conditions may occur and cause reductive decomposition of sulfates from calcined cement raw materials. Decomposition of sulfates is problematic because it increases the gas-phase SO2...... concentration, which may cause deposit formation in the kiln system. In this study, the release of sulfur from calcined cement raw materials under both oxidizing and reducing conditions is investigated. The investigations include thermodynamic equilibrium calculations in the temperature interval of 800–1500 °C...... and experiments in a tube furnace reactor in the temperature interval of 900–1100 °C. The investigated conditions resemble actual conditions in the material inlet end of cement rotary kilns. It was found that the sulfates CaSO4, K2SO4, and Na2SO4 were all stable under oxidizing conditions but began to decompose...

  13. A parametric study of a solar calcinator using computational fluid dynamics

    International Nuclear Information System (INIS)

    Fidaros, D.K.; Baxevanou, C.A.; Vlachos, N.S.

    2007-01-01

    In this work a horizontal rotating solar calcinator is studied numerically using computational fluid dynamics. The specific solar reactor is a 10 kW model designed and used for efficiency studies. The numerical model is based on the solution of the Navier-Stokes equations for the gas flow, and on Lagrangean dynamics for the discrete particles. All necessary mathematical models were developed and incorporated into a computational fluid dynamics model with the influence of turbulence simulated by a two-equation (RNG k-ε) model. The efficiency of the reactor was calculated for different thermal inputs, feed rates, rotational speeds and particle diameters. The numerically computed degrees of calcination compared well with equivalent experimental results

  14. Formation of barium strontium titanate powder by solid state reaction using different calcination temperatures

    International Nuclear Information System (INIS)

    Teoh Wah Tzu; Ahmad Fauzi Mohd Noor; Zainal Arifin Ahmad

    2002-01-01

    The unique electrical properties of large permittivity in Barium Strontium Titanate have been widely used to make capacitors; it can be produced by solid state reaction. In this study, the mixture of Barium Carbonate, Strontium Carbonate and Titanium Dioxide was calcined at 500 degree C, 1000 degree C, 1100 degree C , 1150 degree C, 1200 degree C, 1250 degree C and 1300 degree C. The results of the phases change in each stage were investigated via X ay Diffraction. The results show that the formation of Barium Strontium Titanate started at 1100 degree C with the presence of other phases. The mixture is fully reacted to form Barium Strontium Titanate at 1150 degree C. Only Barium Strontium Titanate was formed as the calcination temperature was set higher. (Author)

  15. Bone mineral change during experimental calcination: an X-ray diffraction study.

    Science.gov (United States)

    Galeano, Sergio; García-Lorenzo, Mari Luz

    2014-11-01

    The effects of calcination (400-1200°C) on pig bones have been studied using powder X-ray diffraction (XRD) and secondary modifications, such as color change and weight loss. The characterisation by powder XRD confirmed the presence of the crystalline phase of hydroxyapatite, and comparison of the results obtained at different temperatures suggested that at 650°C, all the organic components and carbonate substitutions were completely removed. Accordingly, these samples were white. In addition, the crystallinity degree and the crystallite size progressively increased with the calcination temperature until 650°C, remaining stable until 1200°C. Below 650°C, bone samples presented organic compounds, resulting in background noise in the diffractogram and gray or black color. In addition, impurities in the lattice correspond to low crystallite sizes. © 2014 American Academy of Forensic Sciences.

  16. Synthesis of zirconium dioxide by ultrasound assisted precipitation: effect of calcination temperature.

    Science.gov (United States)

    Prasad, Krishnamurthy; Pinjari, D V; Pandit, A B; Mhaske, S T

    2011-09-01

    Nanostructured zirconium dioxide was synthesized from zirconyl nitrate using both conventional and ultrasound assisted precipitation in alkaline medium. The synthesized samples were calcinated at temperatures ranging from 400°C to 900°C in steps of 100°C. The ZrO(2) specimens were characterized using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The thermal characteristics of the samples were studied via Differential Scanning Calorimetry-Thermo-Gravimetry Analysis (DSC-TGA). The influence of the calcination temperature on the phase transformation process from monoclinic to tetragonal to cubic zirconia and its consequent effect on the crystallite size and % crystallinity of the synthesized ZrO(2) was studied and interpreted. It was observed that the ultrasound assisted technique helped to hasten to the phase transformation and also at some point resulted in phase stabilization of the synthesized zirconia. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Conceptual design for remote handling methods using the HIP process in the Calcine Immobilization Program

    International Nuclear Information System (INIS)

    Berry, S.M.; Cox, C.G.; Hoover, M.A.

    1994-03-01

    This report recommends the remote conceptual design philosophy for calcine immobilization using the hot isostatic press (HIP) process. Areas of remote handling operations discussed in this report include: (1) introducing the process can into the front end of the HIP process, (2) filling and compacting the calcine/frit mixture into the process can, (3) evacuating and sealing the process can, (4) non-destructive testing of the seal on the process can, (5) decontamination of the process can, (6) HIP furnace loading and unloading the process can for the HIPing operation, (7) loading an overpack canister with processed HIP cans, (8) sealing the canister, with associated non-destructive examination (NDE) and decontamination, and (9) handling canisters for interim storage at the Idaho Chemical Processing Plant (ICPP) located on the Idaho National Engineering Laboratory (INEL) site

  18. Separation of non-hazardous, non-radioactive components from ICPP calcine via chlorination

    International Nuclear Information System (INIS)

    Nelson, L.O.

    1995-05-01

    A pyrochemical treatment method for separating non-radioactive from radioactive components in solid granular waste accumulated at the Idaho Chemical Processing Plant was investigated. The goal of this study was to obtain kinetic and chemical separation data on the reaction products of the chlorination of the solid waste, known as calcine. Thermodynamic equilibrium calculations were completed to verify that a separation of radioactive and non-radioactive calcine components was possible. Bench-scale chlorination experiments were completed subsequently in a variety of reactor configurations including: a fixed-bed reactor (reactive gases flowed around and not through the particle bed), a packed/fluidized-bed reactor, and a packed-bed reactor (reactive gases flowed through the particle bed). Chemical analysis of the reaction products generated during the chlorination experiments verified the predictions made by the equilibrium calculations. An empirical first-order kinetic rate expression was developed for each of the reactor configurations. 20 refs., 16 figs., 21 tabs

  19. Evaluation and selection of aqueous-based technology for partitioning radionuclides from ICPP calcine

    International Nuclear Information System (INIS)

    Olson, A.L.; Schulz, W.W.; Burchfield, L.A.; Carlson, C.D.; Swanson, J.L.; Thompson, M.C.

    1993-02-01

    Early in 1993 Westinghouse Idaho Nuclear Company (WINCO) chartered a Panel of Nuclear Separations Experts. The purpose of this Panel was to assist WINCO scientists and engineers in selecting, evaluating, and ranking candidate aqueous-based processes and technologies for potential use in partitioning selected radionuclides from nitric acid solutions of retrieved Idaho Chemical Processing Plant (ICPP) calcine. Radionuclides of interest are all transuranium elements, 90 Sr, 99 Tc, 129 I, and 137 Cs. The six man Panel met for 4 days (February 16--19, 1993) on the campus of the Idaho State University in Pocatello, Idaho. Principal topics addressed included: Available radionuclide removal technology; applicability of separations technology and processes to ICPP calcine; and potential integrated radionuclide partitioning schemes. This report, prepared from contributions from all Panel members, presents a comprehensive account of the proceedings and significant findings of the February, 1993 meeting in Pocatello

  20. Influence of calcination temperature in pozolanicity of gray sugar cane bagasse

    International Nuclear Information System (INIS)

    Santos, T.A.; Argolo, R.A.; Andrade, H.M.C.; Ribeiro, D.V.

    2016-01-01

    BCA (Sugar Cane Bagasse) is burned in boilers in the process of electricity cogeneration causing the generation of CBCA (Gray Sugar Cane Bagasse), which is the final residue of sucroalcooeira industry. Currently, several studies seek alternative materials that can replace Portland cement, promoting discussions on the use of pozzolanic materials in cementitious matrices. Thus, this research seeks to analyze the pozzolanicity the CBCA, obtained by calcining the residue at different temperatures, to be determined by TG / DTG and DTA tests. For analysis of pozzolanicity these ashes were used electrical conductivity techniques, chemical titration NP EN 196-5, chapelle modified NBR 15895/2010 and the IAP method (Activity Index pozzolanic NBR:5752). The results obtained during the study demostraramm no difference between the ash calcined at temperatures of 500 ° C, 600 ° C and 700 ° C. (author)

  1. Screw calciner mechanical direct denitration process for plutonium nitrate to oxide conversion

    International Nuclear Information System (INIS)

    Souply, K.R.; Sperry, W.E.

    1977-01-01

    This report describes a screw calciner direct-denitration process for converting plutonium nitrate to plutonium oxide. The information should be used when making comparisons of alternative plutonium nitrate-to-oxide conversion processes or as a basis for further detailed studies. The report contains process flow sheets with a material balance; a process description; and a discussion of the process including history, advantages and disadvantages, and additional research required

  2. 3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

  3. Attrition, elutriation, and growth of particles produced in fluidized-bed waste calciners

    International Nuclear Information System (INIS)

    McDonald, F.N.

    1982-09-01

    The Idaho Chemical Processing Plant reduces the volume of high-level liquid radioactive wastes in a fluidized bed to produce a granular calcine product. In the past, difficulties have been experienced in controlling the product's particle size when processing certain blends of sodium-bearing waste. Therefore, experiments in attrition, elutriation, and particle growth were done to characterize how best to control these three parameters. 15 figures, 16 tables

  4. In-situ investigation of the calcination process of mixed oxide xerogels with Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Panitz, J C [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The controlled calcination of materials derived by sol-gel reactions is important for the evolution of the final structure. Raman spectroscopy is an ideal tool for the identification of surface species under in-situ conditions, as demonstrated in the following for the example of a molybdenum oxide-silica xerogel. Raman spectra of this particular sample were recorded at temperatures as high as 1173 K, and compared with those of a reference material.(author) 3 figs., 4 refs.

  5. Study on Al2O3 extraction from activated coal gangue under different calcination atmospheres

    Science.gov (United States)

    Dong, Ling; Liang, Xinxing; Song, Qiang; Gao, Gewu; Song, Lihua; Shu, Yuanfeng; Shu, Xinqian

    2017-12-01

    Coal gangue was calcinated under air, nitrogen, carbon dioxide, air-hydrogen, and hydrogen atmospheres. The effects of different calcination temperatures and atmospheres on the mineral composition of activated coal gangue were investigated by X-ray diffraction. Moreover, the acid leaching kinetics of aluminum oxide from coal gangue was investigated with sulfuric acid. It showed that the air atmosphere promoted kaolinite decomposition during coal gangue calcination. The hydrogen atmosphere promoted the activation and decomposition of kaolinite at reaction temperatures exceeding 650°C. The carbon dioxide atmosphere eliminated the influence of residual carbon on coal gangue. When the ratio of acid/coal gangue was 1.5 and reaction temperature was 650°C, the sulfuric acid leaching rate under air, air-hydrogen, carbon dioxide, hydrogen and nitrogen atmospheres were 93.66%, 90.90%, 84.06%, 81.91% and 77.54% respectively. The acid leaching reaction process conformed to unreacted shrinking core model of particle unchanged, and was controlled by the interfacial chemical reaction. The reaction kinetic equation for the leaching process was 1-(1-x)1/3=kt with an apparent activation energy of 48.97 kJ/mol.

  6. Effect of Calcination at Synthesis of Mg-Al Hydrotalcite Using co-Precipitation Method

    Directory of Open Access Journals (Sweden)

    Niar Kurnia Julianti

    2017-01-01

    Full Text Available The use of hydrotalcite in catalysis has wide attention in academic research and industrial parties. Based on its utilization, hydrotalcite can be active catalyst or support. This research is focused on the investigation of characteristic like spesific surface area of Mg-Al hydrotalcite which is prepared with different temperature of calcination. Synthesis of Mg-Al hydrotalcites with Mg/Al molar ratio 3:1 were prepared by co-precipitation method. Mg(NO33.6H2O and Al(NO33.9H2O as precursors of Mg-Al hydrotalcite. Na2CO3 was used as precipitant agent and NaOH was used as buffer solution. The solution was mixed and aging for 5 hours at 650oC. The dried precipitate was calcined at 2500oC, 3500oC, 4500oC, 5500oC and 6500oC. The characterization of functional group was determined by Fourier Transform Infra Red (FT-IR. The Identical peaks diffractogram were analyzed by X-Ray Diffraction (XRD. The spesific surface area was determined by adsorption-desorption of nitrogen. The largest surface area that obtained from the calcination temperature of 650oC is 156.252 m2/g.

  7. Effect of calcination temperature on the synthesis of potassium titanate with platy morphology

    International Nuclear Information System (INIS)

    Farina, R.; Fredericci, C.; Yoshimura, H.N.

    2011-01-01

    The dramatic increases in the number of pneumoconiosis cases have stimulated the search of new materials for replacement of asbestos fibers. Titanate plates with formula A y Ti 2-x M x O 4 , where A = K, Rb, Cs and M = Li, Mg, Co, Ni, Cu, Zn, Mn (III), Fe (III) have been studied as an alternative for the use of fibers. The effect of the variation of calcination temperature on the reaction of K 2 CO 3 -TiO 2 -Mg(OH) 2 system was studied with the aim of understanding the relationship of this parameter with the morphology and symmetry of the obtained plates. For this study the samples were calcined for 5 hours at temperatures of 950°C, 1000°C, 1050°C and 1100°C. The powders were analyzed by X-ray diffraction and scanning electron microscopy. It was concluded that 1000°C is the better calcination temperature for obtaining more symmetric plates with smaller particle size dispersion. (author)

  8. Mobile calcination and cementation unit for solidification of concentrated radioactive wastes

    International Nuclear Information System (INIS)

    Napravnik, J.; Sazavsky, P.; Skaba, V.; Skvarenina, R.; Ditl, P.

    1985-01-01

    Mobile experimental unit MESA-1 was developed and manufactured for processing radioactive concentrates by direct cementation. The unit is mainly designed for processing low-level liquid wastes from nuclear power plants and other nuclear installations, in which the level of radioactivity does not exceed 10 10 Bq/m 3 , the salt content of liquid solutions does not exceed 500 kg/m 3 and the maximum amount of boric acid is 130 kg/m 3 . The equipment is built into three modules which may be assembled and dismantled in a short time and transported separately. The unit without the calciner module was tested in non-radioactive mode and in operation with actual radioactive wastes from the V-1 nuclear power plant. The course and results of the tests are described in detail. All project design values were achieved, a total of 18 dm 3 model solutions were processed and 1 m 3 of actual wastes with a salt content of 450 kg/m 3 . The test showed that with regard to the radiation level reached it will be necessary in the process of calcination to increase the shielding of certain exposed points. The calciner module is being assembled for completion. (Z.M.)

  9. Adsorption of basic chromium sulfate used in the tannery industries by calcined hydrotalcite

    International Nuclear Information System (INIS)

    Lopez M, B. E.; Rivera R, R.; Iturbe G, J. L.; Olguin G, M. T.

    2011-01-01

    The sorption behavior of the chemical species of Cr(III) from aqueous solutions by hydrotalcite calcined products was investigated considering the equilibrium ph (5.0 to 8.9) and the chromium concentration in aqueous solution (from 10.6 to 430.0 mmol/L) to obtain the corresponding isotherms. Each solution was prepared from basic Cr(III) sulphate which is a primary tanning agent used in the tannery industries. In this work no previous oxidation treatment was done to form Cr(vi) in order to remove the chromium from aqueous solutions by hydrotalcite. The amount of chromium in the remaining solutions after the sorption processes in a batch system by visible spectroscopy (Vis) was determined. The calcined hydrotalcite before and after the contact with the chromium(III) solutions by X-ray power diffraction, thermogravimetric analysis and Fourier transformed infrared spectroscopy, were characterized. The specific are by Brunauer, Emmett and Teller (Bet) method of each sample was also evaluated. It was found that under the experimental conditions of this work hydrolyzed species of Cr(III) are precipitated on the surface of the calcined hydrotalcite instead other adsorption mechanism, and the sulfate ions were the responsible to regenerated the crystalline structure of hydrotalcite, therefore the results are discussed in terms of both Cr(III) and sulfate chemical species. (Author)

  10. Processing of concentrated radioactive wastes into cement and bitumens following calcination

    International Nuclear Information System (INIS)

    Napravnik, J.; Sazavsky, P.; Ditl, P.; Prikryl, P.

    1985-01-01

    A brief characteristic is presented of the most frequently used processes of solidification of liquid radioactive wastes, viz., bituminization, cementation and their combination with calcination. The effect of individual parameters is assessed on the choice of the type of solidification process as is their importance in the actual process, in temporary storage, during transportation and under conditions of long-term storage. It has been found that a combination of the procedures could lead to a modular system of methods and equipment. This would allow to approach optimal solidification of wastes in the present period and to establish a research reserve for the development of more modern, economically advantageous and safer procedures. A rough estimate is made of the costs of the solidification of 1 m 3 of radioactive concentrate from the V-1 power plant at a production of 380 m 3 /year, this for the cementation-calcination and bituminization-calcination procedures. The said rough economic analysis only serves to identify the major operating components which have the greatest effect on the economic evaluation of the solidification procedures. (Z.M.)

  11. Calcined clay lightweight ceramics made with wood sawdust and sodium silicate

    Energy Technology Data Exchange (ETDEWEB)

    Santis, Bruno Carlos de; Rossignolo, Joao Adriano, E-mail: desantis.bruno@gmail.com [Universidade de Sao Paulo (USP), Pirassununga, SP (Brazil); Morelli, Marcio Raymundo [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Engenharia de Materiais

    2016-11-15

    This paper aims to study the influence of including wood sawdust and sodium silicate in the production process of calcined clay lightweight ceramics. In the production process first, a sample used by a company that produces ceramic products in Brazil was collected. The sample was analysed by techniques of liquidity (LL) and plasticity (LP) limits, particle size analysis, specific mass, X-ray diffraction (XRD) and X ray fluorescence spectrometry (XRF). From the clay, specimens of pure clay and mixtures with wood sawdust (10%, 20% and 30% by mass) and sodium silicate were produced and fired at a temperature of 900 deg C. These specimens were submitted to tests of water absorption, porosity, specific mass and compressive strength. Results of this research indicate that the incorporation of wood sawdust and sodium silicate in the ceramic paste specimens can be useful to make calcined clay lightweight ceramics with special characteristics (low values of water absorption and specific mass and high values of compressive strength), which could be used to produce calcined clay lightweight aggregates to be used in structural concrete. (author)

  12. Connecting section and associated systems concept for the spray calciner/in-can melter process

    International Nuclear Information System (INIS)

    Petkus, L.L.; Gorton, P.S.; Blair, H.T.

    1981-06-01

    For a number of years, researchers at the Pacific Northwest Laboratory have been developing processes and equipment for converting high-level liquid wastes to solid forms. One of these processes is the Spray Calciner/In-Can Melter system. To immobilize high-level liquid wastes, this system must be operated remotely, and the calcine must be reliably conveyed from the calciner to the melting furnace. A concept for such a remote conveyance system was developed at the Pacific Northwest Laboratory, and equipment was tested under full-scale, nonradioactive conditions. This concept and the design of demonstration equipment are described, and the results of equipment operation during experimental runs of 7 d are presented. The design includes a connecting section and its associated systems - a canister sypport and alignment concept and a weight-monitoring system for the melting furnace. Overall, the runs demonstrated that the concept design is an acceptable method of connecting the two pieces of process equipment together. Although the connecting section has not been optimized in all areas of concern, it provides a first-generation design of a production-oriented system

  13. Adsorption of Anionic Dyes from Aqueous Solutions by Calcined and Uncalcined Mg/ Al Layered Double Hydroxide

    International Nuclear Information System (INIS)

    Siti Mariam Sumari; Zaini Hamzah; Kantasamy, N.

    2016-01-01

    The uptake of Acid Blue 29 (AB29), Reactive Orange 16 (RO16) and Reactive Red 120 (RR120) from aqueous solutions by calcined (CLDH) and uncalcined Mg/Al layered double hydroxide (LDH) has been investigated. The adsorption process was conducted in a batch mode at 25 degree Celcius. Anionic dye removal was more efficient using the CLDH rather than LDH. The adsorption process by CLDH involved reconstruction and hydration of the calcined LDH and intercalation of AB29, RO16 and RR120. Physical characterization using X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) were used to ascertain the memory effect phenomenon that is structural reconstruction to regain its original LDH after rehydration. To gain insight into the mechanism of adsorption by CLDH, the pseudo-first order (PFO) and pseudo-second order (PSO) and intraparticle diffusion (IPD) kinetic models were used to analyse experimental data. Based on the correlation coefficient (R 2 ), the PSO has better fitting (R 2 =0.987-1.00) compared to PFO (R 2 =0.867-0.990). Furthermore the values of maximum adsorption capacity, (q e ) calculated from PSO model are consistent with the experimental q e indicating that the experimental kinetic data for AB29, RO16 and RR120 adsorption by CLDH are suitable for this model. Recycling of the adsorbent, in cycles of calcination-reconstruction process promised a possibility of regeneration of CLDH. (author)

  14. Selection of a glass-ceramic formulation to immobilize fluorinel- sodium calcine

    International Nuclear Information System (INIS)

    Staples, B.A.; Wood, H.C.

    1994-12-01

    One option for immobilizing calcined high level wastes produced by nuclear fuel reprocessing activities at the Idaho Chemical Processing Plant (ICPP) is conversion to a glass-ceramic form through hot isostatic pressing. Calcines exist in several different chemical compositions, and thus candidate formulations have been developed for converting each to glass-ceramic forms which are potentially resistant to aqueous corrosion and stable enough to qualify for repository storage. Fluorinel/Na, a chemically complex calcine type, is one of the types being stored at ICPP, and development efforts have identified three formulations with potential for immobilizing it. These are a glass forming additive that uses aluminum metal to enhance reactivity, a second glass forming additive that uses titanium metal to enhance reactivity and a third that uses not only a combination of silicon and titanium metals but enough phosphorous pentoxide to form a calcium phosphate host phase in the glass-ceramic product. Glass-ceramics of each formulation performed well in restricted characterization tests. However, none of the three was subjected to rigorous testing that would provide information on whether each was processable, that is able to retain favorable characteristics over a practical range of processing conditions

  15. Adsorption of basic chromium sulfate used in the tannery industries by calcined hydrotalcite

    Energy Technology Data Exchange (ETDEWEB)

    Lopez M, B. E.; Rivera R, R.; Iturbe G, J. L.; Olguin G, M. T., E-mail: beatriz.lopez@inin.gob.mx [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2011-07-01

    The sorption behavior of the chemical species of Cr(III) from aqueous solutions by hydrotalcite calcined products was investigated considering the equilibrium ph (5.0 to 8.9) and the chromium concentration in aqueous solution (from 10.6 to 430.0 mmol/L) to obtain the corresponding isotherms. Each solution was prepared from basic Cr(III) sulphate which is a primary tanning agent used in the tannery industries. In this work no previous oxidation treatment was done to form Cr(vi) in order to remove the chromium from aqueous solutions by hydrotalcite. The amount of chromium in the remaining solutions after the sorption processes in a batch system by visible spectroscopy (Vis) was determined. The calcined hydrotalcite before and after the contact with the chromium(III) solutions by X-ray power diffraction, thermogravimetric analysis and Fourier transformed infrared spectroscopy, were characterized. The specific are by Brunauer, Emmett and Teller (Bet) method of each sample was also evaluated. It was found that under the experimental conditions of this work hydrolyzed species of Cr(III) are precipitated on the surface of the calcined hydrotalcite instead other adsorption mechanism, and the sulfate ions were the responsible to regenerated the crystalline structure of hydrotalcite, therefore the results are discussed in terms of both Cr(III) and sulfate chemical species. (Author)

  16. Oxyfuel carbonation/calcination cycle for low cost CO2 capture in existing power plants

    International Nuclear Information System (INIS)

    Romeo, Luis M.; Abanades, J. Carlos; Escosa, Jesus M.; Pano, Jara; Gimenez, Antonio; Sanchez-Biezma, Andres; Ballesteros, Juan C.

    2008-01-01

    Postcombustion CO 2 capture is the best suitable capture technology for existing coal power plants. This paper focuses on an emerging technology that involves the separation of CO 2 using the reversible carbonation reaction of CaO to capture CO 2 from the flue gas, and the calcination of CaCO 3 to regenerate the sorbent and produce concentrated CO 2 for storage. We describe the application to this concept to an existing (with today's technology) power plant. The added capture system incorporates a new supercritical steam cycle to take advantage of the large amount of heat coming out from the high temperature capture process (oxyfired combustion of coal is needed in the CaCO 3 calciner). In these conditions, the capture system is able to generate additional power (26.7% efficiency respect to LHV coal input to the calciner after accounting for all the penalties in the overall system), without disturbing the steam cycle of the reference plant (that retains its 44.9 efficiency). A preliminary cost study of the overall system, using well established analogues in the open literature for the main components, yields capture cost around 16 Euro /ton CO 2 avoided and incremental cost of electricity of just over 1 Euro /MW h e

  17. Stabilization of As-, Pb-, and Cu-contaminated soil using calcined oyster shells and steel slag.

    Science.gov (United States)

    Moon, Deok Hyun; Wazne, Mahmoud; Cheong, Kyung Hoon; Chang, Yoon-Young; Baek, Kitae; Ok, Yong Sik; Park, Jeong-Hun

    2015-07-01

    In this study, As-, Pb-, and Cu-contaminated soil was stabilized using calcined oyster shells (COS) and steel slag (SS). The As-contaminated soil was obtained from a timber mill site where chromate copper arsenate (CCA) was used as a preservative. On the other hand, Pb- and Cu-contaminated soil was obtained from a firing range. These two soils were thoroughly mixed to represent As-, Pb-, and Cu-contaminated soil. Calcined oyster shells were obtained by treating waste oyster shells at a high temperature using the calcination process. The effectiveness of stabilization was evaluated by 1-N HCl extraction for As and 0.1-N HCl extraction for Pb and Cu. The treatment results showed that As, Pb, and Cu leachability were significantly reduced upon the combination treatment of COS and SS. The sole treatment of SS (10 wt%) did not show effective stabilization. However, the combination treatment of COS and SS showed a significant reduction in As, Pb, and Cu leachability. The best stabilization results were obtained from the combination treatment of 15 wt% COS and 10 wt% SS. The SEM-EDX results suggested that the effective stabilization of As was most probably achieved by the formation of Ca-As and Fe-As precipitates. In the case of Pb and Cu, stabilization was most probably associated with the formation of pozzolanic reaction products such as CSHs and CAHs.

  18. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    International Nuclear Information System (INIS)

    COMPTON, J.A.

    1999-01-01

    The prototype Vertical Denitration Calciner (VDC) is installed in glovebox 188 in the Plutonium Process Support Laboratory (PPSL). Safety analysis contained in WHC-SD-CP-SAR-021 (FSAR) Rev. 0-L and Addendum to WHC-SD-CP-SAR-021, ''Laboratory Prototype Calciner'' establishes the prototype VDC needs to be shut down if a seismic event of greater than 0.07 g occurs. Shut down is to be automatic upon detection of the seismic event. This requires tie-in of various valves and power for the prototype VDC into the existing Seismic Shutdown System for the Ventilation Supply Fans described in FSAR 5.4.1.2.4. The proposed changes covered by this USQ evaluation include: (1) the physical tie-in modifications, including drawings and Engineering Change Notice (ECN), (2) the work package for accomplishing the modifications, (3) the changes to the System Description Documents, (4) the changes to the Safety Equipment List necessitated by the modifications, and (5) the changes to the failure modes and effects analysis. WHC-SDCP-OSR-010, Plutonium Finishing Plant Operational Safety Requirements Limiting Condition for Operation (LCO) 3.2.3 has been revised to include the requirement for the existing seismic shutdown system to also shut down the laboratory calciner in the event of detection of a greater than 0.07 g seismic event

  19. The effect of calcination on multi-walled carbon nanotubes produced by dc-arc discharge.

    Science.gov (United States)

    Pillai, Sreejarani K; Augustyn, Willem G; Rossouw, Margaretha H; McCrindle, Robert I

    2008-07-01

    Multi-walled carbon nanotubes were synthesized by dc-arc discharge in helium atmosphere and the effect of calcination at different temperatures ranging from 300-600 degrees C was studied in detail. The degree of degradation to the structural integrity of the multi-walled carbon nanotubes during the thermal process was studied by Raman spectroscopy, Scanning electron microscopy and High resolution transmission electron microscopy. The thermal behaviour of the as prepared and calcined samples was investigated by thermogravimetric analysis. Calcination in air at 400 degrees C for 2 hours was found to be an efficient and simple method to eliminate carbonaceous impurities from the nanotube bundles with minimal damage to the tube walls and length. The impurities were oxidized at a faster rate when compared to the nanotubes and gave good yield of about 50%. The nanotubes were observed to be damaged at temperature higher than 450 degrees C. The results show that this method is less destructive when compared liquid phase oxidation with 5 M HNO3.

  20. Test plan for radioactive testing of a vertical direct denitration calciner

    Energy Technology Data Exchange (ETDEWEB)

    COMPTON, J.A.

    1999-08-31

    The prototype Vertical Denitration Calciner (VDC) is installed in glovebox 188 in the Plutonium Process Support Laboratory (PPSL). Safety analysis contained in WHC-SD-CP-SAR-021 (FSAR) Rev. 0-L and Addendum to WHC-SD-CP-SAR-021, ''Laboratory Prototype Calciner'' establishes the prototype VDC needs to be shut down if a seismic event of greater than 0.07 g occurs. Shut down is to be automatic upon detection of the seismic event. This requires tie-in of various valves and power for the prototype VDC into the existing Seismic Shutdown System for the Ventilation Supply Fans described in FSAR 5.4.1.2.4. The proposed changes covered by this USQ evaluation include: (1) the physical tie-in modifications, including drawings and Engineering Change Notice (ECN), (2) the work package for accomplishing the modifications, (3) the changes to the System Description Documents, (4) the changes to the Safety Equipment List necessitated by the modifications, and (5) the changes to the failure modes and effects analysis. WHC-SDCP-OSR-010, Plutonium Finishing Plant Operational Safety Requirements Limiting Condition for Operation (LCO) 3.2.3 has been revised to include the requirement for the existing seismic shutdown system to also shut down the laboratory calciner in the event of detection of a greater than 0.07 g seismic event.

  1. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    Energy Technology Data Exchange (ETDEWEB)

    COMPTON, J.A.

    1999-08-31

    The prototype Vertical Denitration Calciner (VDC) is installed in glovebox 188 in the Plutonium Process Support Laboratory (PPSL). Safety analysis contained in WHC-SD-CP-SAR-021 (FSAR) Rev. 0-L and Addendum to WHC-SD-CP-SAR-021, ''Laboratory Prototype Calciner'' establishes the prototype VDC needs to be shut down if a seismic event of greater than 0.07 g occurs. Shut down is to be automatic upon detection of the seismic event. This requires tie-in of various valves and power for the prototype VDC into the existing Seismic Shutdown System for the Ventilation Supply Fans described in FSAR 5.4.1.2.4. The proposed changes covered by this USQ evaluation include: (1) the physical tie-in modifications, including drawings and Engineering Change Notice (ECN), (2) the work package for accomplishing the modifications, (3) the changes to the System Description Documents, (4) the changes to the Safety Equipment List necessitated by the modifications, and (5) the changes to the failure modes and effects analysis. WHC-SDCP-OSR-010, Plutonium Finishing Plant Operational Safety Requirements Limiting Condition for Operation (LCO) 3.2.3 has been revised to include the requirement for the existing seismic shutdown system to also shut down the laboratory calciner in the event of detection of a greater than 0.07 g seismic event.

  2. Test Plan for Radioactive Testing of a Vertical Direct Denitration Calciner

    Energy Technology Data Exchange (ETDEWEB)

    COMPTON, J.A.

    1999-08-13

    The prototype Vertical Denitration Calciner (VDC) is installed in glovebox 188 in the Plutonium Process Support Laboratory (PPSL). Safety analysis contained in WHC-SD-CP-SAR-021 (FSAR) Rev. 0-L and Addendum to WHC-SD-CP-SAR-021, ''Laboratory Prototype Calciner'' establishes the prototype VDC needs to be shut down if a seismic event of greater than 0.07 g occurs. Shut down is to be automatic upon detection of the seismic event. This requires tie-in of various valves and power for the prototype VDC into the existing Seismic Shutdown System for the Ventilation Supply Fans described in FSAR 5.4.1.2.4. The proposed changes covered by this USQ evaluation include: (1) the physical tie-in modifications, including drawings and Engineering Change Notice (ECN), (2) the work package for accomplishing the modifications, (3) the changes to the System Description Documents, (4) the changes to the Safety Equipment List necessitated by the modifications, and (5) the changes to the failure modes and effects analysis. WHC-SDCP-OSR-010, Plutonium Finishing Plant Operational Safety Requirements Limiting Condition for Operation (LCO) 3.2.3 has been revised to include the requirement for the existing seismic shutdown system to also shut down the laboratory calciner in the event of detection of a greater than 0.07 g seismic event.

  3. Volatilities of ruthenium, iodine, and technetium on calcining fission product nitrate wastes

    International Nuclear Information System (INIS)

    Rimshaw, S.J.; Case, F.N.

    1980-01-01

    Various high-level nitrate wastes were subjected to formic acid denitration. Formic acid reacts with the nitrate anion to yield noncondensable, inert gases according to the following equation: 4 HCOOH + 2 HNO 3 → N 2 O + 4 CO 2 + 5 H 2 O. These gases can be scrubbed free of 106 Ru, 131 I, and 99 Tc radioactivities prior to elimination from the plant by passage through HEPA filters. The formation of deleterious NO/sub x/ is avoided. Moreover, formic acid reduces ruthenium to a lower valence state with a sharp reduction in RuO 4 volatility during subsequent calcination of the pretreated waste. It is shown that a minimum of 3% of RuO 4 in an off-gas stream reacts with Davison silica gel (Grade 40) to give a fine RuO 2 aerosol having a particle size of 0.5 μ. This RuO 2 aerosol passes through water or weak acid scrub solutions but is trapped by a caustic scrub solution. Iodine volatilizes almost completely on calcining an acidic waste, and the iodine volatility increases with increasing calcination temperature. On calcining an alkaline sodium nitrate waste the iodine volatility is about an order of magnitude lower, with a relatively low iodine volatility of 0.39% at a calcination temperature of 250 0 C and a moderate volatility of 9.5% at 600 0 C. Volatilities of 99 Tc were generally 0 C. Data are presented to indicate that 99 Tc concentrates in the alkaline sodium nitrate supernatant waste, with approx. 10 mg 99 Tc being associated with each curie of 137 Cs present in the waste. It is shown that lutidine (2,4 dimethyl-pyridine) extracts Tc(VII) quantitatively from alkaline supernatant wastes. The distribution coefficient (K/sub D/) for Tc(VII) going into the organic phase in the above system is 102 for a simulated West Valley waste and 191 for a simulated Savannah River Plant (SRP) waste

  4. Improvement of the crystallinity and photocatalytic property of zinc oxide as calcination product of Zn–Al layered double hydroxide

    International Nuclear Information System (INIS)

    Ahmed, Abdullah Ahmed Ali; Talib, Zainal Abidin; Hussein, Mohd Zobir bin; Zakaria, Azmi

    2012-01-01

    Highlights: ► ZnO phase and ZnAl 2 O 4 spinel can be formed as Zn–Al–NO 3 –LDH calcination products. ► The crystallinity of ZnO phase increased with an increase of calcination temperature. ► The optical band gaps of ZnO were improved with an increase in temperature. ► The oxygen vacancies in ZnO and ZnAl 2 O 4 generated the ESR signals. - Abstract: Zinc oxide with different degrees of crystallinity can be formed as Zn–Al-layered double hydroxide (Zn–Al–NO 3 –LDH) calcination products. ZnAl 2 O 4 spinel is also formed in a range of calcination temperatures from 600 to 1000 °C from the LDH. X-ray diffraction patterns showed that the crystallinity of the ZnO phase increased as calcination temperatures increased. The LDH structure was fully collapsed at and above 400 °C. The photocatalytic activity was determined by UV–VIS–NIR diffuse reflectance spectroscopy. The band gap of the calcined samples increased as the calcination temperature increased. Electron spin resonance (ESR) spectra of the fresh and calcined LDH at room temperature demonstrated that oxygen vacancies in the ZnO and ZnAl 2 O 4 were responsible for the generation of ESR signals. One BET specific surface area increased from 1 m 2 /g for the LDH to a maximum at 400 °C (43 m 2 /g) and decreased thereafter down to 6 m 2 /g at 1000 °C.

  5. 4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit. The dependence of nitric acid decomposition of calcined boric raw material for extraction of boron oxide on temperature (20-100 deg C) and process duration (15-60 minutes) was defined. It was defined that at temperature increasing the extraction rate of boron oxide increases from 20.8 to 78.6%.

  6. Effect of calcination routes on phase formation of BaTiO3 and their electronic and magnetic properties

    Science.gov (United States)

    Majumder, Supriyo; Choudhary, R. J.; Tripathi, M.; Phase, D. M.

    2018-05-01

    We have investigated the phase formation and correlation between electronic and magnetic properties of oxygen deficient BaTiO3 ceramics, synthesized by solid state reaction method, following different calcination paths. The phase analysis divulge that a higher calcination temperature above 1000° C is favored for tetragonal phase formation than the cubic phase. The core level X-ray photo electron spectroscopy measurements confirm the presence of oxygen vacancies and oxygen vacancy mediated Ti3+ states. As the calcination temperature and calcination time increases these oxygen vacancies and hence Ti3+ concentrations reduce in the sample. The temperature dependent magnetization curves suggest unexpected magnetic ordering, which may be due to the presence of unpaired electron at the t2g state (d1) of nearest-neighbor Ti atoms. In magnetization vs magnetic field isotherms, the regular decrease of saturation moment value with increasing calcination temperature and calcination time, can be discussed considering the amount of oxygen deficiency induced Ti3+ concentrations, present in the sample.

  7. The flashcal process for the fabrication of fuel-metal oxides using the whiteshell roto-spray calciner

    International Nuclear Information System (INIS)

    Sridhar, T.S.

    1988-01-01

    A one-step, continuous, thermochemical calcination process, called the FLASHCAL (Flash Calcination) process has been developed for the production of single- and mixed-oxide powders of fuel metals (uranium, thorium and plutonium) from the respective nitrate solutions using the Whiteshell Roto-Spray Calciner (RSC). The metal-nitrate feed solution, either by itself or mixed with a suitable chemical reactant or additive, is converted to its oxide powder in the RSC at temperatures between 300 and 600 0 C. Rapid denitration takes place in the calciner, yielding the metal-oxide powders while simultaneously destroying any excess chemical additive and reaction by-products. In the production of precursor oxide powders suitable for fuel fabrication, the FLASHCAL process has advantages over batch calcination and other processes that involve precipitation and filtration steps because fewer processing and handling operations are needed. Results obtained with thorium nitrate and uranium nitrate-thorium nitrate mixtures indicate that some measure of control over the size distribution and morphology of the oxide product powders is possible in this process with the proper selection of chemical additive, as well as the operating parameters of the calciner

  8. Role of Calcination Temperature on the Hydrotalcite Derived MgO–Al2O3 in Converting Ethanol to Butanol

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Karthikeyan K.; Gray, Michel J.; Job, Heather M.; Santosa, Daniel M.; Li, Xiaohong S.; Devaraj, Arun; Karkamkar, Abhijeet J.; Wang, Yong

    2015-10-09

    In the base catalyzed ethanol condensation reactions, the calcined MgO-Al2O3 derived hydrotalcites used broadly as catalytic material and the calcination temperature plays a big role in determining the catalytic activity. The characteristic of the hydrotalcite material treated between catalytically relevant temperatures 450ºC and 800ºC have been studied with respect to the physical, chemical, and structural properties and compared with catalytic activity testing. With the increasing calcination temperature, the total measured catalytic basicity dropped linearly with the calcination temperature and the total measured acidity stayed the same for all the calcination temperatures except 800ºC. However, the catalyst activity testing does not show any direct correlation between the measured catalytic basicity and the catalyst activity to the ethanol condensation reaction to form 1-butanol. The highest ethanol conversion of 44 percent with 1-butanol selectivity of 50 percent was achieved for the 600ºC calcined hydrotalcite material.

  9. Effect of calcination temperature on structural properties and photocatalytic activity of Mn-C-codoped TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Jianbo; Xin, Wei; Liu, Guanglong; Lin, Die; Zhu, Duanwei, E-mail: liugl@mail.hzau.edu.cn [Laboratory of Eco-Environmental Engineering Research, College of Resources and Environment, Huazhong Agricultural University (HZAU), Wuhan (China)

    2016-03-15

    Mn-C-codoped TiO{sub 2} catalysts were synthesized by modified sol-gel method based on the self-assembly technique using polyoxyethylene sorbitan monooleate (Tween 80) as template and carbon precursor and the effect of calcination temperature on their structural properties and photocatalytic activity were investigated. The XRD results showed undoped and Mn-C-codoped TiO{sub 2} calcined at 400 deg C only include anatase phase and the rutile phase appears when the calcination temperature reached to 600 deg C. UV-vis absorption spectroscopy demonstrates that the absorption spectra are strongly modified by the calcination temperature. Moreover, the Mn-C-TiO{sub 2} calcined at 400 deg C showed the lowest PL intensity due to a decrease in the recombination rate of photogenerated electrons and holes under light irradiation. The photocatalytic activity of Mn-C-codoped TiO{sub 2} were evaluated by the degradation of methyl orange (MO) under the simulate daylight irradiation and all the prepared Mn-C-codoped TiO{sub 2} samples exhibited high photocatalytic activities for photocatalytic decolorisation of methyl orange aqueous solution. At 400 deg C, the Mn-C-codoped TiO{sub 2} samples showed the highest photocatalytic activity due to synergetic effects of good crystallize ation, appropriate phase composition and slower recombination rate of photogenerated charge carriers, which further confirms the calcination temperature could affect the properties of Mn-C-codoped TiO2 significantly. (author)

  10. Investigation of corrosion experienced in a spray calciner/ceramic melter vitrification system

    International Nuclear Information System (INIS)

    Dierks, R.D.; Mellinger, G.B.; Miller, F.A.; Nelson, T.A.; Bjorklund, W.J.

    1980-08-01

    After periodic testing of a large-scale spray calciner/ceramic melter vitrification system over a 2-yr period, sufficient corrosion was noted on various parts of the vitrification system to warrant its disassembly and inspection. A majority of the 316 SS sintered metal filters on the spray calciner were damaged by chemical corrosion and/or high temperature oxidation. Inconel-601 portions of the melter lid were attacked by chlorides and sulfates which volatilized from the molten glass. The refractory blocks, making up the walls of the melter, were attacked by the waste glass. This attack was occurring when operating temperatures were >1200 0 C. The melter floor was protected by a sludge layer and showed no corrosion. Corrosion to the Inconel-690 electrodes was minimal, and no corrosion was noted in the offgas treatment system downstream of the sintered metal filters. It is believed that most of the melter corrosion occurred during one specific operating period when the melter was operated at high temperatures in an attempt to overcome glass foaming behavior. These high temperatures resulted in a significant release of volatile elements from the molten glass, and also created a situation where the glass was very fluid and convective, which increased the corrosion rate of the refractories. Specific corrosion to the calciner components cannot be proven to have occurred during a specific time period, but the mechanisms of attack were all accelerated under the high-temperature conditions that were experienced with the melter. A review of the materials of construction has been made, and it is concluded that with controlled operating conditions and better protection of some materials of construction corrosion of these systems will not cause problems. Other melter systems operating under similar strenuous conditions have shown a service life of 3 yr

  11. Synthesis and antibacterial evaluation of calcinated Ag-doped nano-hydroxyapatite with dispersibility.

    Science.gov (United States)

    Furuzono, Tsutomu; Motaharul, Mazumder; Kogai, Yasumichi; Azuma, Yoshinao; Sawa, Yoshiki

    2015-05-01

    Dispersible hydroxyapatite (HAp) nanoparticles are very useful for applying a monolayer to implantable medical devices using the nano-coating technique. To improve tolerance to infection on implanted medical devices, silver-doped HAp (Ag-HAp) nanoparticles with dispersiblity and crystallinity were synthesized, avoiding calcination-induced sintering, and evaluated for antibacterial activity. The Ca10-xAgx(PO4)6(OH)2 with x = 0 and 0.2 were prepared by wet chemical processing at 100°C. Before calcination at 700°C for 2 h, two kinds of anti-sintering agents, namely a Ca(NO3)2 (Ca salt) and a polyacrylic acid/Ca salt mixture (PAA-Ca), were used. Escherichia coli was used to evaluate the antibacterial activity of the nanopowder. When PAA-Ca was used as an anti-sintering agent in calcination to prepare the dispersible nanoparticles, strong metallic Ag peaks were observed at 38.1° and 44.3° (2θ) in the X-ray diffraction (XRD) profile. However, the Ag peak was barely observed when Ca salt was used alone as the anti-sintering agent. Thus, using Ca salt alone was more effective for preparation of dispersible Ag-HAp than PAA-Ca. The particle average size of Ag-HAp with 0.5 mol% of Ag content was found to be 325 ± 70 nm when the formation of large particleaggregations was prevented, as determined by dynamic light scattering instrument. The antibacterial activity of the Ag-HAp nanoparticles possessing 0.5 mol% against E. coli was greater than 90.0%. Dispersible and crystalline nano Ag-HAp can be obtained by using Ca salt alone as an anti-sintering agent. The nanoparticles showed antibacterial activity.

  12. Physical, Chemical and Structural Evolution of Zeolite - Containing Waste Forms Produced from Metakaolinite and Calcined HLW

    International Nuclear Information System (INIS)

    Grutzeck, Michael

    2005-01-01

    During the seventh year of the current grant (DE-FG02-05ER63966) we completed an exhaustive study of cold calcination and began work on the development of tank fill materials to fill empty tanks and control residuals. Cold calcination of low and high NOx low activity waste (LAW) SRS Tank 44 and Hanford AN-107 simulants, respectively with metallic Al + Si powders was evaluated. It was found that a combination of Al and Si powders could be used as reducing agents to reduce the nitrate and nitrite content of both low and high NOx LAW to low enough levels to allow the LAW to be solidified directly by mixing it with metakaolin and allowing it to cure at 90 C. During room temperature reactions, NOx was reduced and nitrogen was emitted as N2 or NH3. This was an important finding because now one can pretreat LAW at ambient temperatures which provides a low-temperature alternative to thermal calcination. The significant advantage of using Al and Si metals for denitration/denitrition of the LAW is the fact that the supernate could potentially be treated in situ in the waste tanks themselves. Tank fill materials based upon a hydroceramic binder have been formulated from mixtures of metakaolinite, Class F fly ash and Class C flue gas desulphurization (FGD) ash mixed with various concentrations of NaOH solution. These harden over a period of hours or days depending on composition. A systematic study of properties of the tank fill materials (leachability) and ability to adsorb and hold residuals is under way

  13. Development of a SREX flowsheet for the separation of strontium from dissolved INEEL zirconium calcine

    International Nuclear Information System (INIS)

    Law, J.D.; Wood, D.J.; Todd, T.A.

    1999-01-01

    Laboratory experimentation has indicated that the SREX process is effective for partitioning 90 Sr from acidic radioactive waste solutions located at the Idaho Nuclear Technology and Engineering Center. These laboratory results were used to develop a flowsheet for countercurrent testing of the SREX process with dissolved pilot plant calcine. Testing was performed using 24 stages of 2-cm diameter centrifugal contactors which are installed in the Remote Analytical Laboratory hot cell. Dissolved Run No.64 pilot plant calcine spiked with 85 Sr was used as feed solution for the testing. The flowsheet tested consisted of an extraction section (0.15 M 4prime,4prime(5prime)-di-(tert-butylcyclohexo)-18-crown-6 and 1.5 M TBP in Isopar-L.), a 1.0 M NaNO 3 scrub section to remove extracted K from the SREX solvent, a 0.01 M HNO 3 strip section for the removal of Sr from the SREX solvent, a 0.25 M Na2CO 3 wash section to remove degradation products from the solvent, and a 0.1 M HNO 3 rinse section. The behavior of 85 Sr, Na, K, Al, B, Ca, Cr, Fe, Ni, and Zr was evaluated. The described flowsheet successfully extracted 85 Sr from the dissolved pilot plant calcine with a removal efficiency of 99.6%. Distribution coefficients for 85 Sr ranged from 3.6 to 4.5 in the extraction section. With these distribution coefficients a removal efficiency of approximately >99.99% was expected. It was determined that the lower than expected removal efficiency can be attributed to a stage efficiency of only 60% in the extraction section. Extracted K was effectively scrubbed from the SREX solvent with the 1.0 M NaNO 3 resulting in only 6.4% of the K in the HLW strip product. Sodium was not extracted from the dissolved calcine by the SREX solvent; however, the use of a 1.0 M NaNO 3 scrub solution resulted in a Na concentration of 70 mg/L (12.3% of the feed concentration) in the HLW strip product. Al, B, Ca, Cr, Fe, Ni, and Zr were determined to be essentially inextractable

  14. Structure and pozzolanic activity of calcined coal gangue during the process of mechanical activation

    Energy Technology Data Exchange (ETDEWEB)

    Wei Guo; Dongxu Li; Jianhua Chen; Nanru Yang [Yancheng Institute of Technology, Yancheng (China). Department of Material Engineering

    2009-04-15

    On the basis of analyzing coal gangue's chemical and mineral compositions, the structure change of coal gangue during the mechanical activation was investigated by XRD, FTIR, NMR, and the mechanical strength of the cement doped coal gangue with various specific surface area was tested. The experimental results indicate that the lattice structure of metakaolin in coal gangue samples calcined at 700{sup o}C disorganizes gradually and becomes disordered, and the lattice structure of {alpha}-quartz is distorted slightly. The pozzolanic activity of the coal gangue increases obviously with its structural disorganization.

  15. Volume reduction of low- and medium-level waste by incineration/calcination

    International Nuclear Information System (INIS)

    Buzonniere, A. de; Gauthey, J.C.

    1993-01-01

    Nuclear installations generate large quantities of low- and medium-level radwaste. This waste comes from various installations in the fuel cycle, reactor operation, research institute, hospitals, nuclear plate dismantling, etc.. TECHNICATOME did the project development work for the incineration plant of PIERRELATE (France) on behalf of COGEMA (Compagnie Generale des d'Etudes Technique). This plant has been in active service since November 1987. In addition, TECHNICATOME was in charge of the incinerator by a turnkey contract. This incinerator was commissioned in 1992. For a number of years, TECHNICATOME has been examining, developing and producing incineration and drying/calcination installations. They are used for precessing low- and medium-level radwaste

  16. Vitrification of radioactive high-level waste by spray calcination and in-can melting

    Science.gov (United States)

    Hanson, M. S.; Bjorklund, W. J.

    1980-07-01

    After several nonradioactive test runs, radioactive waste from the processing of 1.5 t of spent, light water reactor fuel was successfully concentrated, dried and converted to a vitreous product. A total of 97 L of waste glass (in two stainless steel canisters) was produced. The spray calcination process coupled to the in-can melting process, as developed at Pacific Northwest Labortory, was used to vitrify the waste. An effluent system consisting of a variety of condensation of scrubbing steps more than adequately decontaminated the process off gas before it was released to the atmosphere.

  17. Conceptual design for vitrification of HLW at West Valley using a rotary calciner/metallic melter

    International Nuclear Information System (INIS)

    Giraud, J.P.; Conord, J.P.; Saverot, P.M.

    1984-01-01

    The CEA has had an extensive research program in the field of vitrification technology for over 24 years, and several testing facilities were used throughout all phases of development and engineering: The Vulcain facility comprises a vitrification hot cell and four auxiliary hot cells. Vulcain allows the production of 2-kg samples of active glass. The off-gas treatment system allows testing the DF of each equipment. The auxiliary cells are equipped with leach-rate tests, diffusion tests, and irradiation tests on the glass samples. The Atlas facility is a reproduction of AVM calcination and vitrification furnaces at 1/2 scale enclosed in a glove box. This facility is used for testing ruthenium volatility and containment in the vitrification process. The full-scale AVM inactive pilot facility is used for testing calcination and vitrification of new compositions of high-level waste and for developing new types of vitrification furnaces. The inactive test loop is for testing air cooling of glass containers. The full-scale AVH inactive pilot facility is used for testing AVH technology and has been in operation since late 1981

  18. Removal of acid blue 062 on aqueous solution using calcinated colemanite ore waste

    Energy Technology Data Exchange (ETDEWEB)

    Atar, Necip [Department of Chemistry, Faculty of Arts and Science, University of Dumlupinar, Kuetahya (Turkey); Olgun, Asim [Department of Chemistry, Faculty of Arts and Science, University of Dumlupinar, Kuetahya (Turkey)]. E-mail: aolgun@dumlupinar.edu.tr

    2007-07-19

    Colemanite ore waste (CW) has been employed as adsorbent for the removal of acid blue 062 anionic dye (AB 062) from aqueous solution. The adsorption of AB 062 onto CW was examined with respect to contact time, calcination temperature, particle size, pH, adsorbent dosage and temperature. The physical and chemical properties of the CW, such as particle sizes and calcinations temperature, play important roles in dye adsorption. The dye adsorption largely depends on the initial pH of the solution with maximum uptake occurring at pH 1.Three simplified kinetics models, namely, pseudo-first order, pseudo-second order, and intraparticle diffusion models were tested to investigate the adsorption mechanisms. The kinetic adsorption of AB 062 on CW follows a pseudo-second order equation. The adsorption data have been analyzed using Langmuir and Freundlich isotherms. The results indicate that the Langmuir model provides the best correlation of the experimental data. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of the adsorption of dye onto CW.

  19. Removal of acid blue 062 on aqueous solution using calcinated colemanite ore waste

    International Nuclear Information System (INIS)

    Atar, Necip; Olgun, Asim

    2007-01-01

    Colemanite ore waste (CW) has been employed as adsorbent for the removal of acid blue 062 anionic dye (AB 062) from aqueous solution. The adsorption of AB 062 onto CW was examined with respect to contact time, calcination temperature, particle size, pH, adsorbent dosage and temperature. The physical and chemical properties of the CW, such as particle sizes and calcinations temperature, play important roles in dye adsorption. The dye adsorption largely depends on the initial pH of the solution with maximum uptake occurring at pH 1.Three simplified kinetics models, namely, pseudo-first order, pseudo-second order, and intraparticle diffusion models were tested to investigate the adsorption mechanisms. The kinetic adsorption of AB 062 on CW follows a pseudo-second order equation. The adsorption data have been analyzed using Langmuir and Freundlich isotherms. The results indicate that the Langmuir model provides the best correlation of the experimental data. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of the adsorption of dye onto CW

  20. Photocatalytic hydrogen evolution of palladium nanoparticles decorated black TiO2 calcined in argon atmosphere

    Science.gov (United States)

    Wu, Ming-Chung; Hsiao, Kai-Chi; Chang, Yin-Hsuan; Chan, Shun-Hsiang

    2018-02-01

    Black TiO2 nanoparticles (BTN) was prepared by sol-gel derived precursor calcined in an argon atmosphere. The synthesized BTN with trivalent titanium ion, structural defect, and oxygen vacancy shows a remarkably high absorbance in the visible light spectrum. BTN thus behaves a higher visible-active nanoreactor than white TiO2 nanoparticles (WTN) in the aqueous solution for organic pollutant degradation. Moreover, palladium decoration on the BTN surface (Pd-BTN) demonstrates a fascinating clean energy application. The obtained Pd-BTN fulfills a satisfied green material demand in the photocatalytic hydrogen production application. Pd-BTN calcined at 400 °C (Pd-BTN-400) shows the high photocatalytic hydrogen generation rate of 5200 μmol/g h under UV-A irradiation and 9300 μmol/g h under UV-B irradiation, respectively. The well-developed material, Pd-BTN-400, could be one of the best solutions in the concern of clean energy and water-purification with regard to the continuous environmental issue.

  1. Synthesis, structure and photocatalytic activity of calcined Mg-Al-Ti-layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Hosni, Khaled; Abdelkarim, Omar; Srasra, Ezzeddine [Centre National des Recherches en Sciences des Matériaux (CNRSM), Soliman (Turkey); Frini-Srasra, Najoua [Faculté des Sciences de Tunis (FST), Tunis (Turkey)

    2015-01-15

    Mg-Al-Ti layered double hydroxides (LDH), consisting of di-, tri- and tetra-valent cations with different Al{sup 3+}/Ti{sup 4+} ratio, have been synthesized by co-precipitation which was demonstrated as efficient visible-light photocatalysts. The structure and chemical composition of the compound were characterized by PXRD, FT-IR, SAA, N{sub 2} adsorption-desorption isotherms, and DSC techniques. It is found that no hydrotalcites structure were formed for Ti{sup 4+}/(Ti{sup 4+}+ Al{sup 3+})>0.5 and the substitution of Ti(IV) for Al(III) in the layer increases the thermal stability of the resulting LDH materials. The calcined sample containing titanium showed relatively high adsorption capacity for MB as compared to that without titanium. Results show that the pseudo-second-order kinetic model and the Langmuir were found to correlate the experimental data well. The photocatalytic activity was evaluated for the degradation of the methylene blue. The photocatalytic activity increased with the increase of the Al/Ti cationic ratio. 71% of the dye could be removed by the Mg/Al/Ti-LDH with the cationic ratio Al/Ti=0 : 1 and calcined at 500 .deg. C.

  2. Calcined hydrotalcites for the catalytic decomposition of N{sub 2}O in simulated process streams

    Energy Technology Data Exchange (ETDEWEB)

    Armor, J.N.; Braymer, T.A.; Farris, T.S.; Li, Y.; Petrocelli, F.P.; Weist, E.L. [Air Products and Chemicals, Inc., Allentown, PA (United States); Kannan, S.; Swamy, C.S. [Department of Chemistry, Indian Institute of Technology, Madras (India)

    1996-01-18

    Various hydrotalcite based catalysts were prepared for testing for the catalytic decomposition of N{sub 2}O. Co-Al, Ni-Al, Co/Pd-Al, Co/Rh-Al, and Co/Mg-Al substituted hydrotalcites and Co-La-Al hydroxides offer very good activity at modest temperatures. Precalcination of these materials at ca. 450-500C, which destroys the hydrotalcite phase, is necessary for optimum activity and life. For Co substituted hydrotalcites, the optimal ratio of Co/Al is 3.0. The temperature for 50% conversion of N{sub 2}O of these calcined cobalt hydrotalcites is ca. 75C lower than for the previous highly active Co-ZSM-5. These calcined cobalt hydrotalcite materials display sustained life at temperatures in excess of 670C in an O{sub 2} rich, wet stream with high levels of N{sub 2}O (10%). Excess O{sub 2} does not seriously impact N{sub 2}O decomposition, but the combination of both water vapor and O{sub 2} does reduce activity by ca. 50%

  3. Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of calcined alumina

    Directory of Open Access Journals (Sweden)

    Pattem Hemanth Kumar

    2014-12-01

    Full Text Available A new class of conventional and low-cement ferrochrome slag-based castables were prepared from 40 wt.% ferrochrome slag and 45 wt.% calcined bauxite. Rest fraction varied between high alumina cement (HAC acting as hydraulic binder and calcined alumina as pore filling additive. Standard ASTM size briquettes were prepared for crushing and bending strengths evaluation, and the samples were then subjected to firing at 800, 1100 and 1300 °C for a soaking period of 3 h. The microstructure and refractory properties of the prepared castables have been investigated using X-ray diffraction (XRD, scanning electron microscopy (SEM, cold crushing strength, modulus of rupture and permanent linear changes (PLCs test. Castables show good volume stability (linear change <0.7% at 1300 °C. The outcomes of these investigations were efficacious and in accordance with previously reported data of similar compositions. High thermo-mechanical and physico-chemical properties were attained pointing out an outstanding potential to increase the refractory lining working life of non-recovery coke oven and reheating furnaces.

  4. Manganese oxide phases and morphologies: A study on calcination temperature and atmospheric dependence

    Directory of Open Access Journals (Sweden)

    Matthias Augustin

    2015-01-01

    Full Text Available Manganese oxides are one of the most important groups of materials in energy storage science. In order to fully leverage their application potential, precise control of their properties such as particle size, surface area and Mnx+ oxidation state is required. Here, Mn3O4 and Mn5O8 nanoparticles as well as mesoporous α-Mn2O3 particles were synthesized by calcination of Mn(II glycolate nanoparticles obtained through an economical route based on a polyol synthesis. The preparation of the different manganese oxides via one route facilitates assigning actual structure–property relationships. The oxidation process related to the different MnOx species was observed by in situ X-ray diffraction (XRD measurements showing time- and temperature-dependent phase transformations occurring during oxidation of the Mn(II glycolate precursor to α-Mn2O3 via Mn3O4 and Mn5O8 in O2 atmosphere. Detailed structural and morphological investigations using transmission electron microscopy (TEM and powder XRD revealed the dependence of the lattice constants and particle sizes of the MnOx species on the calcination temperature and the presence of an oxidizing or neutral atmosphere. Furthermore, to demonstrate the application potential of the synthesized MnOx species, we studied their catalytic activity for the oxygen reduction reaction in aprotic media. Linear sweep voltammetry revealed the best performance for the mesoporous α-Mn2O3 species.

  5. Effects of Composition and Calcination Temperature on Photocatalytic Evolution over from Glycerol and Water Mixture

    Directory of Open Access Journals (Sweden)

    Cancan Fan

    2012-01-01

    Full Text Available A series of sulfide coupled semiconductors supported on SiO2, (, was prepared by incipient wet impregnation method. The photocatalysts were characterized by XRD, XPS, TPR, and UV/Vis DRS. Characterization results show that the chemical actions between ZnS and CdS resulted in the formation of solid solutions on the surface of the support and the formation of them is affected by the molar ratio of ZnS/CdS and calcination temperature. Performance of photocatalysts was tested in the home made reactor under both UV light and solar-simulated light irradiation by detecting the rate of the photocatalytic H2 evolution from glycerol solution. The hydrogen production rates are related to the catalyst composition, surface structure, photoabsorption property, as well as the amount of solid solution. The maximum rate of hydrogen production, 550 μmol·h−1 under UV light irradiation and 210 μmol·h−1 under solar-simulated light irradiation, was obtained over Cd0.8Zn0.2S/SiO2 solid solution calcined at 723 K.

  6. Calcination temperature influenced multiferroic properties of Ca-doped BiFeO3 nanoparticles

    International Nuclear Information System (INIS)

    Dhir, Gitanjali; Uniyal, Poonam; Verma, N. K.

    2015-01-01

    The influence of Ca-doping and particle size on structural, morphological and magnetic properties of BiFeO 3 nanoparticles has been studied. A sol-gel method was employed for the synthesis of nanoparticles and their particle size was tailored by varying the calcination temperature. Structural analysis revealed a rhombohedral distortion induced by Ca-substitution. The broadening of diffraction peaks with decreasing calcination temperature was indicative of reduction in crystallite size. The morphological analysis revealed the formation of agglomerated nanoparticles having average particle size ranging from 10-15 and 50-55 nm for C4 and C6, respectively. The agglomeration is attributed to high surface energy of nanoparticles. Ferromagnetism has been displayed by all the synthesized nanoparticles. Enhancement of saturation magnetization with Ca-substitution is attributed to suppression of spin cycloid structure by the reduction in size, lattice distortion and creation of oxygen vacancies by the substitution of divalent ion at trivalent site. Further, this value increases as a function of decreasing particle size. Strong particle size effects on magnetic properties of the synthesized nanoparticles are owed to increasing surface to volume ratio. All these observations are indicative of strong dependence of multiferroism on particle size

  7. Evaluation of calcination temperature and phase composition ratio for new hyroxyapatite

    Science.gov (United States)

    Salimi, M. N. Ahmad; Chin, H. S.

    2017-10-01

    The demand of production of hydroxyapatite (HA) has been increasing for the purpose of medical and dental application. HA possesses the excellent properties leads to the priority choice for ceramic bone replacement. Synthesis route by wet chemical precipitation is commonly practised in industrial scale. Calcium hydroxide and Orthophosphoric acid are the precursors for production scale. The synthesis of HA is conducted by varying the synthetic condition: stirring rate, calcium-phosphate and calcination temperature. This paper is focused on the properties of HA produced by regulating the synthetic condition so that the qualities of HA can be well performed. Characterization studies were also carried out by Fourier Transform Infrared Spectroscopy (FT-IR) for functional group identification, Scanning Electron Microscope (SEM) for surface morphology analysis and X-Ray Diffraction (XRD) for phase composition and crystallinity respectively. Narrow particle size distribution contributed to better quality of hydroxyapatite for bone replacement. Both calcium-phosphate ratio and calcination temperature would affect the phase composition of calcium phosphate.

  8. Mercury removal at Idaho National Engineering and Environmental Laboratory's New Waste Calcining Facility

    Energy Technology Data Exchange (ETDEWEB)

    S. C. Ashworth

    2000-02-27

    Technologies were investigated to determine viable processes for removing mercury from the calciner (NWCF) offgas system at the Idaho National Engineering and Environmental Laboratory. Technologies for gas phase and aqueous phase treatment were evaluated. The technologies determined are intended to meet EPA Maximum Achievable Control Technology (MACT) requirements under the Clean Air Act and Resource Conservation and Recovery Act (RCRA). Currently, mercury accumulation in the calciner off-gas scrubbing system is transferred to the tank farm. These transfers lead to accumulation in the liquid heels of the tanks. The principal objective for aqueous phase mercury removal is heel mercury reduction. The system presents a challenge to traditional methods because of the presence of nitrogen oxides in the gas phase and high nitric acid in the aqueous scrubbing solution. Many old and new technologies were evaluated including sorbents and absorption in the gas phase and ion exchange, membranes/sorption, galvanic methods, and UV reduction in the aqueous phase. Process modifications and feed pre-treatment were also evaluated. Various properties of mercury and its compounds were summarized and speciation was predicted based on thermodynamics. Three systems (process modification, NOxidizer combustor, and electrochemical aqueous phase treatment) and additional technology testing were recommended.

  9. Mercury Removal at Idaho National Engineering and Environmental Laboratory's New Waste Calcining Facility

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, Samuel Clay; Wood, R. A.; Taylor, D. D.; Sieme, D. D.

    2000-03-01

    Technologies were investigated to determine viable processes for removing mercury from the calciner (NWCF) offgas system at the Idaho National Engineering and Environmental Laboratory. Technologies for gas phase and aqueous phase treatment were evaluated. The technologies determined are intended to meet EPA Maximum Achievable Control Technology (MACT) requirements under the Clean Air Act and Resource Conservation and Recovery Act (RCRA). Currently, mercury accumulation in the calciner off-gas scrubbing system is transferred to the tank farm. These transfers lead to accumulation in the liquid heels of the tanks. The principal objective for aqueous phase mercury removal is heel mercury reduction. The system presents a challenge to traditional methods because of the presence of nitrogen oxides in the gas phase and high nitric acid in the aqueous scrubbing solution. Many old and new technologies were evaluated including sorbents and absorption in the gas phase and ion exchange, membranes/sorption, galvanic methods, and UV reduction in the aqueous phase. Process modifications and feed pre-treatment were also evaluated. Various properties of mercury and its compounds were summarized and speciation was predicted based on thermodynamics. Three systems (process modification, NOxidizer combustor, and electrochemical aqueous phase treatment) and additional technology testing were recommended.

  10. Memory effect of calcined layered samarium hydroxy chlorides in aqueous solution

    International Nuclear Information System (INIS)

    Lee, Byung Il; Byeon, Song Ho

    2015-01-01

    The decomposition and recovery behavior of layered samarium hydroxychloride (Sm 2 (OH) 5 Cl·nH 2 O, LSmH) has been closely studied in various conditions. Although the heat treatment of LSmH at 700 °C completely collapsed typical layered structure, the calcined LSmH (c-LSmH) recovered its layered characteristics and consequently its ability to intercalate anions into the interlayer space when it was rehydroxylated and rehydrated in aqueous solutions containing organic and inorganic anions. This phenomenon is similar to the memory effect observed in classical layered double hydroxides (LDHs), where LDHs calcined to a mixture of metal oxides can recover their layered structures in aqueous solutions. In contrast, the recovery reaction of c-LSmH in water without any counter anions was unsuccessful and instead resulted in the formation of Sm(OH) 3 . Such a difference was interpreted on the basis of the salt effect on Sm 2 (OH) 5 Cl·nH 2 O–Sm(OH) 3 phase equilibria in water

  11. Mercury removal at Idaho National Engineering and Environmental Laboratory's New Waste Calciner Facility

    International Nuclear Information System (INIS)

    Ashworth, S.C.

    2000-01-01

    Technologies were investigated to determine viable processes for removing mercury from the calciner (NWCF) offgas system at the Idaho National Engineering and Environmental Laboratory. Technologies for gas phase and aqueous phase treatment were evaluated. The technologies determined are intended to meet EPA Maximum Achievable Control Technology (MACT) requirements under the Clean Air Act and Resource Conservation and Recovery Act (RCRA). Currently, mercury accumulation in the calciner off-gas scrubbing system is transferred to the tank farm. These transfers lead to accumulation in the liquid heels of the tanks. The principal objective for aqueous phase mercury removal is heel mercury reduction. The system presents a challenge to traditional methods because of the presence of nitrogen oxides in the gas phase and high nitric acid in the aqueous scrubbing solution. Many old and new technologies were evaluated including sorbents and absorption in the gas phase and ion exchange, membranes/sorption, galvanic methods, and UV reduction in the aqueous phase. Process modifications and feed pre-treatment were also evaluated. Various properties of mercury and its compounds were summarized and speciation was predicted based on thermodynamics. Three systems (process modification, NOxidizer combustor, and electrochemical aqueous phase treatment) and additional technology testing were recommended

  12. Influence of calcination process on the formation of selected air pollutants

    Directory of Open Access Journals (Sweden)

    Wydrych Jacek

    2017-01-01

    Full Text Available The subject of the study is to analyze the phenomena of thermal flow in the precalcinator chamber of the exchanger's furnace tower including the combustion of coal dust and decarbonisation of raw lime powder. During the research were provided development of a mathematical model of particulate solid fuels combustion, calcining the raw material, NOx and COx formation. Moreover conducting the number for the current and the upgraded design of the precalcinator and analysis of the results. In this study, a mathematical model based on Euler's method to describe the motion of the gas phase and the Lagrange method to describe the motion of particles [1-4]. In the calculations there were assumed fractional particles raw material and fuel, and the following processes: flow of exhaust gases from the rotary kiln through the precalcinator chamber, heat exchange between the particles of raw material and exhaust gases, the additional fuel combustion in the precalcinator, the process of raw material calcination, transformation of gaseous substances, effect of the additional (tertiary air delivery on the processes in the chamber.

  13. Easily recycled Bi2O3 photocatalyst coatings prepared via ball milling followed by calcination

    Science.gov (United States)

    Cheng, Lijun; Hu, Xumin; Hao, Liang

    2017-06-01

    Bi2O3 photocatalyst coatings derived from Bi coatings were first prepared by a two-step method, namely ball milling followed by the calcination process. The as-prepared samples were characterized by XRD, SEM, XPS and UV-Vis spectra, respectively. The results showed that monoclinic Bi2O3 coatings were obtained after sintering Bi coatings at 673 or 773 K, while monoclinic and triclinic mixed phase Bi2O3 coatings were obtained at 873 or 973 K. The topographies of the samples were observably different, which varied from flower-like, irregular, polygonal to nanosized particles with the increase in calcination temperature. Photodegradation of malachite green under simulated solar irradiation for 180 min showed that the largest degradation efficiency of 86.2% was achieved over Bi2O3 photocatalyst coatings sintered at 873 K. The Bi2O3 photocatalyst coatings, encapsulated with Al2O3 ball with an average diameter around 1 mm, are quite easily recycled, which provides an alternative visible light-driven photocatalyst suitable for practical water treatment application.

  14. Pecularities of carrying out radioactive wastes vitrification process without preliminary calcination of wastes

    International Nuclear Information System (INIS)

    Konstantinovich, A.A.; Kulichenko, V.V.; Bel'tyukov, V.A.; Nikiforov, A.S.; Nikipelov, B.V.; Stepanov, S.E.; Baskov, L.I.; Kulakov, S.I.

    1978-01-01

    Vitrification technology is considered for liquid radioactive wastes by means of electric furnace where heating of glass-paste is done by electric current passing through the melt. Continious process of gehydration, calcination and vitrification is going on in one apparatus. Testing if the method has been performed by use of a model solution, containing sodium and aluminium nitrates. To obtain phosphoric acid has been added into the solution. Lay-out of the device and its description as well as technical parameters of the electric furnace are given. The results are stated for determination of the optimum operation conditions for the device. To reduce entrainment of solid components, molasses has been added in the solution. Parameters are given for the process of the solution containing 80 g/l molasses processing. It has been shown that edding molasses to the solution permitted to reduse power consumption of the process due to the heat generation during oxidation-reduction reaction on the melt surface. The results are given for investigations of the nitrogen oxides catching in scrubbers. These results have shown that introduction of molasses reduces nitrigen oxides concentration. The results of the experimental works have shown the possibility of the continious process of dehydration, calcination and vitrification in single device with application of remote control and monitoring by means of automatics. (I.T.) [ru

  15. Effects of milling method and calcination condition on phase and morphology characteristics of Mg4Nb2O9 powders

    International Nuclear Information System (INIS)

    Wongmaneerung, R.; Sarakonsri, T.; Yimnirun, R.; Ananta, S.

    2006-01-01

    Magnesium niobate, Mg 4 Nb 2 O 9 , powders has been synthesized by a solid-state reaction. Both conventional ball- and rapid vibro-milling have been investigated as milling methods, with the formation of the Mg 4 Nb 2 O 9 phase investigated as a function of calcination conditions by DTA and XRD. The particle size distribution of the calcined powders was determined by laser diffraction technique, while morphology, crystal structure and phase composition were determined via a combination of SEM, TEM and EDX techniques. The type of milling method together with the designed calcination condition was found to show a considerable effect on the phase and morphology evolution of the calcined Mg 4 Nb 2 O 9 powders. It is seen that optimization of calcination conditions can lead to a single-phase Mg 4 Nb 2 O 9 in both milling methods. However, the formation temperature and dwell time for single-phase Mg 4 Nb 2 O 9 powders were lower with the rapid vibro-milling technique

  16. Idaho National Engineering and Environmental Laboratory, Old Waste Calcining Facility, Scoville vicinity, Butte County, Idaho -- Photographs, written historical and descriptive data. Historical American engineering record

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    This report describes the history of the Old Waste Calcining Facility. It begins with introductory material on the Idaho National Engineering and Environmental Laboratory, the Materials Testing Reactor fuel cycle, and the Idaho Chemical Processing Plant. The report then describes management of the wastes from the processing plant in the following chapters: Converting liquid to solid wastes; Fluidized bed waste calcining process and the Waste Calcining Facility; Waste calcining campaigns; WCF gets a new source of heat; New Waste Calcining Facility; Last campaign; Deactivation and the RCRA cap; Significance/context of the old WCF. Appendices contain a photo key map for HAER photos, a vicinity map and neighborhood of the WCF, detailed description of the calcining process, and chronology of WCF campaigns.

  17. Idaho National Engineering and Environmental Laboratory, Old Waste Calcining Facility, Scoville vicinity, Butte County, Idaho -- Photographs, written historical and descriptive data. Historical American engineering record

    International Nuclear Information System (INIS)

    1997-01-01

    This report describes the history of the Old Waste Calcining Facility. It begins with introductory material on the Idaho National Engineering and Environmental Laboratory, the Materials Testing Reactor fuel cycle, and the Idaho Chemical Processing Plant. The report then describes management of the wastes from the processing plant in the following chapters: Converting liquid to solid wastes; Fluidized bed waste calcining process and the Waste Calcining Facility; Waste calcining campaigns; WCF gets a new source of heat; New Waste Calcining Facility; Last campaign; Deactivation and the RCRA cap; Significance/context of the old WCF. Appendices contain a photo key map for HAER photos, a vicinity map and neighborhood of the WCF, detailed description of the calcining process, and chronology of WCF campaigns

  18. Cyclic carbonation calcination studies of limestone and dolomite for CO{sub 2} separation from combustion flue gases - article no. 011801

    Energy Technology Data Exchange (ETDEWEB)

    Senthoorselvan, S.; Gleis, S.; Hartmut, S.; Yrjas, P.; Hupa, M. [TUM, Garching (Germany)

    2009-01-15

    Naturally occurring limestone and dolomite samples, originating from different geographical locations, were tested as potential sorbents for carbonation/calcination based CO{sub 2} capture from combustion flue gases. Samples have been studied in a thermogravimetric analyzer under simulated flue gas conditions at three calcination temperatures, viz., 750{sup o}C, 875{sup o}C, and 930{sup o}C for four carbonation calcination reaction (CCR) cycles. The dolomite sample exhibited the highest rate of carbonation than the tested limestones. At the third cycle, its CO{sub 2} capture capacity per kilogram of the sample was nearly equal to that of Gotland, the highest reacting limestone tested. At the fourth cycle it surpassed Gotland, despite the fact that the CaCO{sub 3} content of the Sibbo dolomite was only 2/3 of that of the Gotland. Decay coefficients were calculated by a curve fitting exercise and its value is lowest for the Sibbo dolomite. That means, most probably its capture capacity per kilogram of the sample would remain higher well beyond the fourth cycle. There was a strong correlation between the calcination temperature, the specific surface area of the calcined samples, and the degree of carbonation. It was observed that the higher the calcination temperature, the lower the sorbent reactivity. For a given limestone/dolomite sample, sorbents CO{sub 2} capture capacity depended on the number of CCR cycles and the calcination temperature. According to the equilibrium thermodynamics, the CO{sub 2} partial pressure in the calciner should be lowered to lower the calcination temperature. This can be achieved by additional steam supply into the calciner. Steam could then be condensed in an external condenser to single out the CO{sub 2} stream from the exit gas mixture of the calciner. A calciner design based on this concept is illustrated.

  19. Effect of calcinations temperature of CuO nanoparticle on the kinetics of decontamination and decontamination products of sulphur mustard.

    Science.gov (United States)

    Mahato, T H; Singh, Beer; Srivastava, A K; Prasad, G K; Srivastava, A R; Ganesan, K; Vijayaraghavan, R

    2011-09-15

    Present study investigates the potential of CuO nanoparticles calcined at different temperature for the decontamination of persistent chemical warfare agent sulphur mustard (HD) at room temperature (30 ± 2 °C). Nanoparticles were synthesized by precipitation method and characterized by using SEM, EDAX, XRD, and Raman Spectroscopy. Synthesized nanoparticles were tested as destructive adsorbents for the degradation of HD. Reactions were monitored by GC-FID technique and the reaction products characterized by GC-MS. It was observed that the rate of degradation of HD decreases with the increase in calcination temperature and there is a change in the percentage of product of HD degradation. GC-MS data indicated that the elimination product increases with increase in calcination temperature whereas the hydrolysis product decreases. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    International Nuclear Information System (INIS)

    Sun, Zhiming; Zhang, Yuzhong; Zheng, Shuilin; Park, Yuri; Frost, Ray L.

    2013-01-01

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value

  1. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

    2013-04-20

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

  2. Physical and chemical characteristics of fluorinel/sodium calcine generated during 30 cm Pilot-Plant Run 17

    International Nuclear Information System (INIS)

    Brewer, K.N.; Kessinger, G.F.; Littleton, L.L.; Olson, A.L.

    1993-07-01

    The 30 centimeter (cm) pilot plant calciner Run 17, of March 9, 1987, was performed to study the calcination of fluroinel-sodium blended waste blended at the ratio 3.5:1 fluorinel to sodium, respectively. The product of the run was analyzed by a variety of analytical techniques that included X-ray powder diffraction (XRD), inductively coupled plasma spectroscopy (ICP), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) to deduce physical and chemical characteristics. The analytical data, as well as data analyses and conclusions drawn from the data, are presented

  3. Retrofit design of remotely removable decontamination spray nozzles for the new waste calcining facility at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Gay, J.A.

    1988-01-01

    High level radioactive liquid waste is converted to a solid form at the Idaho Chemical Processing Plant (ICPP). The conversion is done by a fluidized bed combustion process in the calciner vessel. The interior decontamination system for the calciner vessel uses a common header bolted to four decontamination nozzles around the upper head. The retrofit was required to eliminate hands-on maintenance and difficulty in nozzle removal because of nozzle plugging. The retrofit design for this project demonstrates the solution of problems associated with thermal phenomena, structural supports, seismic requirements, remote handling and installations into extremely restricted spaces

  4. Twofold role of calcined hydrotalcites in the degradation of methyl parathion pesticide

    Directory of Open Access Journals (Sweden)

    Alvaro Sampieri

    2011-02-01

    Full Text Available Methyl parathion (MP is a very toxic organophosphate pesticide used as a non-systematic insecticide and acaricide on many corps. As MP and its by-products are highly toxic, they have to be retained to avoid pollution of rivers and lakes. Highly efficient sorbents are hydrotalcites (HTs (or anionic clays. We have correlated the degradation of an aqueous solution of MP at room temperature, with the basicity of the adsorbing materials. It was found that the metal composition of hydrotalcites determines both the surface electronic properties (basic or acidic and the sorption capacity. Depending on the basic strength, some calcined hydrotalcites can catalyze the transformation of MP to p-nitrophenol (p-NP and retain its by-products. Such a process has the advantage of being able to be carried out at room temperature and at the pH of the pesticide solution.

  5. Influence of temperature on the synthesis of calcining cement α--tricalcium phosphate

    International Nuclear Information System (INIS)

    Vieira, R.S.; Thurmer, M.B.; Coelho, W.T.; Fernandes, J.M.; Santos, L.A.

    2011-01-01

    The calcium phosphate cement (CFCs) bone substitutes are of great potential use in medical and dental. However, one of the great difficulties of using this type of cement is its low mechanical strength due to the presence of undesirable phases, such as beta-tricalcium phosphate. The step of obtaining this compound is done at high temperature by solid state reaction. With the aim of obtaining calcium phosphate cements more resistant, we studied the conditions for obtaining an alpha-TCP at temperatures of 1300, 1400 and 1500 ° C with time 2h calcination. The samples were analyzed for crystalline phases, density, porosity and mechanical strength. The results show that the synthesis parameters studied strongly influence the obtained phases and the mechanical properties of cement. (author)

  6. Chemistry of application of calcination/dissolution to the Hanford tank waste inventory

    International Nuclear Information System (INIS)

    Delegard, C.H.; Elcan, T.D.; Hey, B.E.

    1994-05-01

    Approximately 330,000 metric tons of sodium-rich radioactive waste originating from separation of plutonium from irradiated uranium fuel are stored in underground tanks at the Hanford Site in Washington State. Fractionation of the waste into low-level waste (LLW) and high-level waste (HLW) streams is envisioned via partial water dissolution and limited radionuclide extraction operations. Under optimum conditions, LLW would contain most of the chemical bulk while HLW would contain virtually all of the transuranic and fission product activity. Calcination at around 850 C, followed by water dissolution, has been proposed as an alternative initial treatment of Hanford Site waste to improve waste dissolution and the envisioned LLW/HLW split. Results of literature and laboratory studies are reported on the application of calcination/dissolution (C/D) to the fractionation of the Hanford Site tank waste inventory. Both simulated and genuine Hanford Site waste materials were used in the lab tests. To evaluation confirmed that C/D processing reduced the amount of several components from the waste. The C/D dissolutions of aluminum and chromium allow redistribution of these waste components from the HLW to the LLW fraction. Comparisons of simple water-washing with C/D processing of genuine Hanford Site waste are also reported based on material (radionuclide and chemical) distributions to solution and solid residue phases. The lab results show that C/D processing yielded superior dissolution of aluminum and chromium sludges compared to simple water dissolution. 57 refs., 26 figs., 18 tabs

  7. Synthesis of Cd/(Al+Fe) layered double hydroxides and characterization of the calcination products

    International Nuclear Information System (INIS)

    Perez, M.R.; Barriga, C.; Fernandez, J.M.; Rives, V.; Ulibarri, M.A.

    2007-01-01

    Layered double hydroxides (LDHs) containing Cd(II), Al(III), and Fe(III) in the brucite-like layers with different starting Fe/Al atomic ratios and with nitrate as counteranion have been prepared following the coprecipitation method at a constant pH value of 8. An additional Cd(II),Al(III)-LDH sample interlayered with hexacyanoferrate(III) ions has been prepared by ionic exchange at pH 9. The samples have been characterized by elemental chemical analysis, powder X-ray diffraction (PXRD), and FT-IR spectroscopy. Their thermal stability has been assessed by thermogravimetric and differential thermal analyses (TG-DTA) and mass spectrometric analysis of the evolved gases. The PXRD patterns of the solids calcined at 800 deg. C show diffraction lines corresponding to Cd(Al)O and spinel-type materials, which precise nature (CdAl 2 O 4 , Cd 1-x Fe 2+x O 4 , or Cd x Fe 2.66 O 4 ) depends on location and concentration of iron in the parent material or precursor. - Graphical abstract: Layered double hydroxides (LDHs) containing Cd(II), Al(III), and Fe(III) in the brucite-like layers with different starting Fe/Al atomic ratios and with nitrate as counteranion have been prepared following the coprecipitation method. An additional Cd(II),Al(III)-LDH sample interlayered with hexacyanoferrate(III) ions has been prepared by ionic exchange. Calcination at 800 deg. C shows diffraction lines corresponding to CdO and to spinel-type materials. SEM micrograph of sample CdAlFe-N-0

  8. Development of mesoporosity in scandia-stabilized zirconia: particle size, solvent, and calcination effects.

    Science.gov (United States)

    Cahill, James T; Ruppert, Jesse N; Wallis, Bryce; Liu, Yanming; Graeve, Olivia A

    2014-05-20

    We present the mechanisms of formation of mesoporous scandia-stabilized zirconia using a surfactant-assisted process and the effects of solvent and thermal treatments on the resulting particle size of the powders. We determined that cleaning the powders with water resulted in better formation of a mesoporous structure because higher amounts of surfactant were preserved on the powders after washing. Nonetheless, this resulted in agglomerate sizes that were larger. The water-washed powders had particle sizes of >5 μm in the as-synthesized state. Calcination at 450 and 600 °C reduced the particle size to ∼1-2 and 0.5 μm, respectively. Cleaning with ethanol resulted in a mesoporous morphology that was less well-defined compared to the water-washed powders, but the agglomerate size was smaller and had an average size of ∼250 nm that did not vary with calcination temperature. Our analysis showed that surfactant-assisted formation of mesoporous structures can be a compromise between achieving a stable mesoporous architecture and material purity. We contend that removal of the surfactant in many mesoporous materials presented in the literature is not completely achieved, and the presence of these organics has to be considered during subsequent processing of the powders and/or for their use in industrial applications. The issue of material purity in mesoporous materials is one that has not been fully explored. In addition, knowledge of the particle (agglomerate) size is essential for powder handling during a variety of manufacturing techniques. Thus, the use of dynamic light scattering or any other technique that can elucidate particle size is essential if a full characterization of the powders is needed for achieving postprocessing effectiveness.

  9. Proposed Atomic Energy of Canada Ltd. 99Mo waste calcination process

    International Nuclear Information System (INIS)

    Ramey, D.W.; Haas, P.A.; Malkemus, D.W.; McGinnis, C.P.; Meyers, E.S.; Patton, B.D.; Birdwell, J.F.; Jubin, R.T.; Coltharp, K.A.

    1994-10-01

    Atomic Energy of Canada Limited (AECL), at its Chalk River Laboratory, generates from 3000 to 5000 L/year of high-level fissile waste solution from the production of 99 Mo. In this Mo process, highly enriched uranium (93 wt % 235 U, total uranium basis) contained in uranium-aluminum alloy target rods is irradiated to produce the 99 Mo product. The targets are removed from the reactor and dissolved in a mercury nitrate-catalyzed reaction with nitric acid. The 99 Mo product is then recovered by passing the solution through an alumina (Al 2 O 3 ) column. During discussions with personnel from the Oak Ridge National Laboratory (ORNL) on September 10, 1992, the ORNL-developed technology formerly applied to the solidification of aqueous uranium waste (Consolidated Edison Uranium Solidification Program or CEUSP) was judged potentially applicable to the AECL 99 Mo waste. Under a Work-for-Others contract (no. ERD-92-1132), which began May 24, 1993, ORNL was tasked to determine the feasibility of applying the CEUSP (or a similar) calcination process to solidify AECL's 99 Mo waste for > 30 years of safe dry storage. This study was to provide sufficient detailed information on the applicability of a CEUSP-type waste solidification process to allow AECL to select the process which best suited its needs. As with the CEUSP process, evaporation of the waste and a simultaneously partial destruction of acid by reaction with formaldehyde followed by in situ waste can thermal denitration waste was chosen as the best means of solidification. Unlike the CEUSP material, the 99 Mo waste has a considerable number of problem volatile and semivolatile constituents which must be recovered in the off-gas treatment system. Mercury removal before calcination was seen as the best option

  10. Surface complexation modeling calculation of Pb(II) adsorption onto the calcined diatomite

    Science.gov (United States)

    Ma, Shu-Cui; Zhang, Ji-Lin; Sun, De-Hui; Liu, Gui-Xia

    2015-12-01

    Removal of noxious heavy metal ions (e.g. Pb(II)) by surface adsorption of minerals (e.g. diatomite) is an important means in the environmental aqueous pollution control. Thus, it is very essential to understand the surface adsorptive behavior and mechanism. In this work, the Pb(II) apparent surface complexation reaction equilibrium constants on the calcined diatomite and distributions of Pb(II) surface species were investigated through modeling calculations of Pb(II) based on diffuse double layer model (DLM) with three amphoteric sites. Batch experiments were used to study the adsorption of Pb(II) onto the calcined diatomite as a function of pH (3.0-7.0) and different ionic strengths (0.05 and 0.1 mol L-1 NaCl) under ambient atmosphere. Adsorption of Pb(II) can be well described by Freundlich isotherm models. The apparent surface complexation equilibrium constants (log K) were obtained by fitting the batch experimental data using the PEST 13.0 together with PHREEQC 3.1.2 codes and there is good agreement between measured and predicted data. Distribution of Pb(II) surface species on the diatomite calculated by PHREEQC 3.1.2 program indicates that the impurity cations (e.g. Al3+, Fe3+, etc.) in the diatomite play a leading role in the Pb(II) adsorption and dominant formation of complexes and additional electrostatic interaction are the main adsorption mechanism of Pb(II) on the diatomite under weak acidic conditions.

  11. Chemistry of application of calcination/dissolution to the Hanford tank waste inventory

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, C.H.; Elcan, T.D.; Hey, B.E.

    1994-05-01

    Approximately 330,000 metric tons of sodium-rich radioactive waste originating from separation of plutonium from irradiated uranium fuel are stored in underground tanks at the Hanford Site in Washington State. Fractionation of the waste into low-level waste (LLW) and high-level waste (HLW) streams is envisioned via partial water dissolution and limited radionuclide extraction operations. Under optimum conditions, LLW would contain most of the chemical bulk while HLW would contain virtually all of the transuranic and fission product activity. Calcination at around 850 C, followed by water dissolution, has been proposed as an alternative initial treatment of Hanford Site waste to improve waste dissolution and the envisioned LLW/HLW split. Results of literature and laboratory studies are reported on the application of calcination/dissolution (C/D) to the fractionation of the Hanford Site tank waste inventory. Both simulated and genuine Hanford Site waste materials were used in the lab tests. To evaluation confirmed that C/D processing reduced the amount of several components from the waste. The C/D dissolutions of aluminum and chromium allow redistribution of these waste components from the HLW to the LLW fraction. Comparisons of simple water-washing with C/D processing of genuine Hanford Site waste are also reported based on material (radionuclide and chemical) distributions to solution and solid residue phases. The lab results show that C/D processing yielded superior dissolution of aluminum and chromium sludges compared to simple water dissolution. 57 refs., 26 figs., 18 tabs.

  12. Stabilized γ-BIMNVOX solid electrolyte: Ethylene glycol–citrate sol–gel synthesis, microwave-assisted calcination, and structural and electrical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Al-Areqi, Niyazi A.S., E-mail: niyazi.alareqi@gmail.com [Department of Chemistry, Faculty of Applied Science, Taiz University, Taiz, Republic of Yemen (Yemen); Beg, Saba [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India); Al-Alas, Ahlam [Department of Chemistry, Faculty of Applied Science, Taiz University, Taiz, Republic of Yemen (Yemen); Hafeez, Shehla [Department of Chemistry, Aligarh Muslim University, Aligarh 202002 (India)

    2013-12-25

    Highlights: •γ-BIMNVOX was synthesized by ethylene glycol–citrate sol–gel route. •γ-BIMNVOX crystallizes by 25-min microwave-assisted calcination. •Smaller particle sizes for microwave calcined BIMNVOX samples. •Best oxide-ion performance for microwave calcined BIMNVOX samples. -- Abstract: Samples of γ-BIMNVOX (Bi{sub 2}V{sub 1−x}Mn{sub x}O{sub 5.5−x/2}; 0.13 ⩽ x ⩽ 0.20) system were synthesized by an ethylene glycol–citrate sol–gel route. The resulting xerogels were then calcined by the microwave heating using a modified domestic microwave oven operated at 2.45 GHz. Microwave-assisted calcination samples in comparison with other conventionally calcined samples were characterized in terms of phase crystallization, stabilization and particle size using simultaneous thermogravimetric–differential thermal analysis (TG–DTA), X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM). The AC impedance spectroscopy was employed for electrical characterization. It was found that the microwave-assisted calcination route successfully produces better crystalline stabilized γ-BIMNVOX samples with appreciably small average particle sizes after only 25 min of microwave heating. The electrical properties of microwave calcined γ-BIMNVOX system make it an advanced low-temperature solid electrolyte suitable for use in oxide-ion based electrochemical applications.

  13. To study the effect of dopant NiO concentration and duration of calcinations on structural and optical properties of MgO-NiO nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajesh, E-mail: rkkaushik06@gmail.com [Deptt. of Physics, M.D. University, Rohtak-124001, Haryana (India); Deptt. of Physics,Vaish College of Engineering, Rohtak-124001, Haryana (India); Praveen,; Sharma, Ashwani; Parmar, R.; Dahiya, S. [Deptt. of Physics, M.D. University, Rohtak-124001, Haryana (India); Kishor, N. [Deptt. of Physics, Central University of Haryana (India)

    2016-05-06

    In present work Magnesium oxide (MgO) samples were doped with different concentration of Transition metal Nickel Oxide(NiO) by using Chemical co-precipitation method. The doping levels were varied from NiO (5%, 10%, 15%) and all the samples were calcined at 600°C for 4hrs and 8hrs respectively. Structural analysis of these calcined materials is carried out by X-ray diffraction (XRD) techniques which reveals that average crystalline sizes are in nano region i.e. 21.77nm-31.13 nm and tabulated in table 1. The powder of calcined samples were also characterized by using various other techniques i.e. Scanning Electron Microscopy (SEM), Fourier Transformation Infrared Spectroscopy (FTIR), UV-Visible spectroscopy, Transmission Electron Microscopy (TEM) etc. The effects of dopant concentration, calcined temperature, calcinations duration on samples were studied and also investigate the effect of varying dopant concentration on morphology and optical properties of calcined nanomaterials. From results it was observed that the crystallite size of nanocomposites increases with increases dopant concentration or increases calcinations duration. The optical band gap decreases with increases sintering time and increase with increases dopant concentrations. TEM results coincide with XRD results and show that particles are polycrystalline in nature. FTIR spectra show that for all samples particles are pure in composition and transmission rate increases with calcinations duration.

  14. Moessbauer characterization of calcium-ferrite oxides prepared by calcining Fe2O3 and CaO

    International Nuclear Information System (INIS)

    Hirabayashi, Daisuke; Sakai, Yoichi; Yoshikawa, Takeshi; Mochizuki, Kazuhiro; Kojima, Yoshihiro; Suzuki, Kenzi; Ohshita, Kazumasa; Watanabe, Yasuo

    2006-01-01

    Calcium ferrite oxides were prepared by calcining a mixture powder of iron- and calcium oxide. The 57 Fe-Moessbauer spectra of the calcium ferrites oxides were measured, revealing that the products should be Ca 2 Fe 2 O 5 and CaFe 2 O 4 , the ratio of which was dependent of the Fe/Ca atomic ratio of the mixture powder.

  15. Improvement of Gold Leaching from a Refractory Gold Concentrate Calcine by Separate Pretreatment of Coarse and Fine Size Fractions

    Directory of Open Access Journals (Sweden)

    Qian Li

    2017-05-01

    Full Text Available A total gold extraction of 70.2% could only be reached via direct cyanidation from a refractory As-, S- and C-bearing gold concentrate calcine, and the gold extraction varied noticeably with different size fractions. The reasons for unsatisfactory gold extraction from the calcine were studied through analyses of chemical composition, chemical phase and SEM-EDS of different sizes of particles. It was found that a significant segregation of compositions occurred during the grinding of gold ore before flotation. As a result, for the calcine obtained after oxidative roasting, the encapsulation of gold by iron oxides was easily engendered in finer particles, whilst in coarser particles the gold encapsulation by silicates was inclined to occur likely due to melted silicates blocking the porosity of particles. The improvement of gold leaching from different size fractions was further investigated through pretreatments with alkali washing, acid pickling or sulfuric acid curing-water leaching. Finally, a novel process was recommended and the total gold extraction from the calcine could be increased substantially to 93.6% by the purposeful pretreatment with alkali washing for the relatively coarse size fraction (+37 μm and sulfuric acid curing–water leaching for the fine size fraction (−37 μm.

  16. Influence of calcination temperature on sol-gel synthesized single-phase bismuth titanate for high dielectric capacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Thiruramanathan, Pandirengan; Marikani, Arumugam [Mepco Schlenk Engineering College, Tamil Nadu (India). Dept. of Physics; Madhavan, Durairaj [Mepco Schlenk Engineering College, Tamil Nadu (India). Dept. of Chemistry; Bharadwaj, Suresh; Awasthi, Anand Mohan [UGC-DAE Consortium for Scientific Research, Indore (India). Thermodynamics Lab.

    2016-05-15

    An inexpensive sol-gel combustion method using citric acid as fuel has been used to synthesize bismuth titanate, Bi{sub 4}Ti{sub 3}O{sub 12} nanopowders. Thermogravimetric analysis proved that a calcination temperature of 900 C is sufficient for the preparation of single-phase bismuth titanate. X-ray diffraction and Fourier transform infrared spectroscopy are used to examine the influence of calcination temperature on the structural growth of the Bi{sub 4}Ti{sub 3}O{sub 12} nanopowder. The average crystallite size estimated by using the Scherrer method and the Williamson-Hall method was found to increase with calcination temperature. Photoluminescence behavior as a function of calcination temperature was observed at two different excitation wavelengths of 300 nm and 420 nm. The morphology of the particles analyzed using images obtained from field emission scanning electron microscopy displayed irregular, random sized, and spherical-shaped structures. The stoichiometry and purity of the nanopowder are confirmed by energy-dispersive spectroscopy. The broadband dielectric results established the highest dielectric constant (ε{sub r} = 450) for a frequency of 100 Hz achieved with a potential capacitance of 138 pF m{sup -2}. This establishes Bi{sub 4}Ti{sub 3}O{sub 12} as a promising dielectric material for achieving high energy density capacitors for the next-generation passive devices.

  17. Prediction model of ammonium uranyl carbonate calcination by microwave heating using incremental improved Back-Propagation neural network

    Energy Technology Data Exchange (ETDEWEB)

    Li Yingwei [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Peng Jinhui, E-mail: jhpeng@kmust.edu.c [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Liu Bingguo [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Li Wei [Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Huang Daifu [No. 272 Nuclear Industry Factory, China National Nuclear Corporation, Hengyang, Hunan Province 421002 (China); Zhang Libo [Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China); Key Laboratory of Unconventional Metallurgy, Ministry of Education, Kunming University of Science and Technology, Kunming, Yunnan Province 650093 (China)

    2011-05-15

    Research highlights: The incremental improved Back-Propagation neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward. The prediction model of the nonlinear system is built, which can effectively predict the experiment of microwave calcining of ammonium uranyl carbonate (AUC). AUC can accept the microwave energy and microwave heating can quickly decompose AUC. In the experiment of microwave calcining of AUC, the contents of U and U{sup 4+} increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth. - Abstract: The incremental improved Back-Propagation (BP) neural network prediction model was put forward, which was very useful in overcoming the problems, such as long testing cycle, high testing quantity, difficulty of optimization for process parameters, many training data probably were offered by the way of increment batch and the limitation of the system memory could make the training data infeasible, which existed in the process of calcinations for ammonium uranyl carbonate (AUC) by microwave heating. The prediction model of the nonlinear system was built, which could effectively predict the experiment of microwave calcining of AUC. The predicted results indicated that the contents of U and U{sup 4+} were increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth.

  18. Effect of calcination environments and plasma treatment on structural, optical and electrical properties of FTO transparent thin films

    Directory of Open Access Journals (Sweden)

    Madhav Kafle

    2017-07-01

    Full Text Available The dependence of the structural, optical and electrical properties of the FTO thin films on the film thickness (276 nm - 546 nm, calcination environment, and low temperature plasma treatment were examined. The FTO thin films, prepared by spray pyrolysis, were calcinated under air followed by either further heat treatment under N2 gas or treatment in low temperature atmospheric plasma. The samples before and after calcination under N2, and plasma treatment will be represented by Sair, SN2 and SPl, respectively, hereafter. The thin films were characterized by measuring the XRD spectra, SEM images, optical transmittance and reflectance, and sheet resistance of the films before and after calcination in N2 environment or plasma treatment. The presence of sharp and narrow multiple peaks in XRD spectra hint us that the films were highly crystalline (polycrystalline. The samples Sair with the thickness of 471 nm showed as high as 92 % transmittance in the visible range. Moreover, from the tauc plot, the optical bandgap Eg values of the Sair found to be noticeably lower than that of the samples SN2. Very surprisingly, the electrical sheet resistance (Rsh found to decrease following the trend as Rshair > RshN2 > RshPl. The samples exposed to plasma found to possess the lowest RshPl (for film with thickness 546 nm, the RshPl was 17 Ω/sq..

  19. Prediction model of ammonium uranyl carbonate calcination by microwave heating using incremental improved Back-Propagation neural network

    International Nuclear Information System (INIS)

    Li Yingwei; Peng Jinhui; Liu Bingguo; Li Wei; Huang Daifu; Zhang Libo

    2011-01-01

    Research highlights: → The incremental improved Back-Propagation neural network prediction model using the Levenberg-Marquardt algorithm based on optimizing theory is put forward. → The prediction model of the nonlinear system is built, which can effectively predict the experiment of microwave calcining of ammonium uranyl carbonate (AUC). → AUC can accept the microwave energy and microwave heating can quickly decompose AUC. → In the experiment of microwave calcining of AUC, the contents of U and U 4+ increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth. - Abstract: The incremental improved Back-Propagation (BP) neural network prediction model was put forward, which was very useful in overcoming the problems, such as long testing cycle, high testing quantity, difficulty of optimization for process parameters, many training data probably were offered by the way of increment batch and the limitation of the system memory could make the training data infeasible, which existed in the process of calcinations for ammonium uranyl carbonate (AUC) by microwave heating. The prediction model of the nonlinear system was built, which could effectively predict the experiment of microwave calcining of AUC. The predicted results indicated that the contents of U and U 4+ were increased with increasing of microwave power and irradiation time, and decreased with increasing of the material average depth.

  20. Influence of calcination temperature on the zirconia microstructure synthesized by complex polymerization method (CPM): a comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.L.P.; Mota, F.V.; Nascimento, R.M.; Henriques, B.P.; Silva, F.S.; Assis, R. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2016-07-01

    Full text: The aim of this study was to accomplish a previous characterization of the zirconia synthesized by Complex Polymerization Method (CPM) using yttria as stabilizing agent and different calcination temperatures. The powders were crystallized at 800, 900 and 1000 °C for 2h. The structural evolution Y-TZP powders were characterized by X-Ray Diffraction (XRD) and Micro-Raman Spectroscopy. The thermal properties of the calcined pre-pyrolyzed (350 °C for 4 h), samples were investigated by simultaneous thermo analysis (TGA/DTA). After heat treatment the phase Y-TZP was obtained of a single-phase, with absence of the deleterious phases. The results show that average crystallite size of the powder synthesized with 3% of Yttria dopant, increased from 11.5 to 27.9 nm when the calcination temperature increased from 800 to 1000 °C. This behavior was observed for all specimens independent of the Yttria content. The micro-Raman indicate the presence of the tetragonal phase for all samples independent of the calcination temperature employed. (author)

  1. Development and Testing of the Advanced CHP System Utilizing the Off-Gas from the Innovative Green Coke Calcining Process in Fluidized Bed

    Energy Technology Data Exchange (ETDEWEB)

    Chudnovsky, Yaroslav [Gas Technology Inst., Des Plaines, IL (United States); Kozlov, Aleksandr [Gas Technology Inst., Des Plaines, IL (United States)

    2013-08-15

    Green petroleum coke (GPC) is an oil refining byproduct that can be used directly as a solid fuel or as a feedstock for the production of calcined petroleum coke. GPC contains a high amount of volatiles and sulfur. During the calcination process, the GPC is heated to remove the volatiles and sulfur to produce purified calcined coke, which is used in the production of graphite, electrodes, metal carburizers, and other carbon products. Currently, more than 80% of calcined coke is produced in rotary kilns or rotary hearth furnaces. These technologies provide partial heat utilization of the calcined coke to increase efficiency of the calcination process, but they also share some operating disadvantages. However, coke calcination in an electrothermal fluidized bed (EFB) opens up a number of potential benefits for the production enhancement, while reducing the capital and operating costs. The increased usage of heavy crude oil in recent years has resulted in higher sulfur content in green coke produced by oil refinery process, which requires a significant increase in the calcinations temperature and in residence time. The calorific value of the process off-gas is quite substantial and can be effectively utilized as an “opportunity fuel” for combined heat and power (CHP) production to complement the energy demand. Heat recovered from the product cooling can also contribute to the overall economics of the calcination process. Preliminary estimates indicated the decrease in energy consumption by 35-50% as well as a proportional decrease in greenhouse gas emissions. As such, the efficiency improvement of the coke calcinations systems is attracting close attention of the researchers and engineers throughout the world. The developed technology is intended to accomplish the following objectives: - Reduce the energy and carbon intensity of the calcined coke production process. - Increase utilization of opportunity fuels such as industrial waste off-gas from the novel

  2. Adsorption behavior of calcined layered double hydroxides towards removal of iodide contaminants

    International Nuclear Information System (INIS)

    Lu Liang; He Jing; Wei Min; Evans, D.G.; Duan Xue

    2005-01-01

    Layered double hydroxides (LDHs), are a class of synthetic anionic clays whose structure can be described as containing brucite-like layers in which some of the divalent cations have been replaced by trivalent ions giving positively-charged sheets. This charge is balanced by intercalation of anions in the hydrated interlayer regions. The general formula is EM 2+ 1-x M 3+ x (OH) 2 ] x+ (A n- ) x/n · mH 2 O, where M 2+ and M 3+ are metal cations for example Mg 2+ and Al 3+ , that occupy octahedral sites in the hydroxide layers, A n- is an exchangeable anion, and x is the ratio M 3+ /(M 2+ + M 3+ ) and the layer charge will depend on the M 2+ /M 3+ ratio. LDHs act as sorbents of anionic species through two types of reactions, namely, anion exchange and reconstruction, which further adds the possibility of recycling and reuse. The sorption of anions from aqueous solutions by structural reconstruction of a calcined LDH is based on a very interesting property of these materials, the so-called memory effect: Calcination of LDHs produces intermediate non-stoichiometric oxides (CLDH) which undergo rehydration in aqueous medium and give back the hydroxide structure with different anions in the interlayers. Radioactive iodide is widely used in biological experiments, medical treatments and in diagnosis. During fission of uranium several iodine species are produced. All the short lived isotopes of iodine, including 1311 (half life 8.04 days), decay and only 127 I (stable) and 129 I (half life 1.59 x 10 7 years) remain as a problem. 129 I is especially considered as one of the key radionuclides that dominate the long-term radiation in underground radioactive waste stores. Iodine is one of the nuclides causing most concern among radioactive anions. Different adsorbents such as zeolites, silica gel, anion exchange paper membrane, activated carbon and activated carbon fibers, have been investigated as potential materials for elimination of iodide from liquid wastes. In this work

  3. Infrared detection of the mineralogical aspects that influence the processing of calcined kaolin

    Science.gov (United States)

    Groenheide, Stefan; Guatame-Garcia, Adriana; Buxton, Mike; van der Werff, Harald

    2017-04-01

    Calcined kaolin is an industrial minerals product used in the production of paper, paint, rubber and other specialty applications. It is produced from kaolinite through a series of refinement steps and final calcination at temperatures of above 900°C, with the aim of generating a whiter and more abrasive material. The raw kaolin ore is a mixture of clay minerals, quartz and feldspars, where kaolinite is the main constituent. The optimal kaolin ores to feed the processing plant should ideally have high kaolinite abundance, be free in Fe-bearing mineralogy (to avoid influence in the colour of the product), and the kaolinite itself should be of high crystallinity (to ensure the correct abrasiveness after calcination). This work presents a case study from the kaolin deposits in the St. Austell Granite (South-West England), which are known for their high quality and world-class size. In this area, the kaolin is of primary-hydrothermal origin, with mineral associations that are related to the genetic history. The eventual depletion of the high-quality reserves is bringing now the attention to the lower grade zones, where the amount of impurities increases. As a consequence, it is critical to developing strategies that ensure the supply of high-quality ore to the processing plant. For this, it is necessary to acquire a thorough knowledge of the ore, including relative abundance of the minerals and their textural relationships. Hyperspectral images in the visible-near infrared (VNIR) and short-wave infrared (SWIR) ranges were collected from drill cores and run-off-mine (ROM) samples, obtained from one of the kaolin pits in the St. Austell area, where the kaolin quality is known to be lower than in the rest of the deposit. A series of mineral maps were generated to assess the distribution, texture and abundance of the Fe-bearing mineralogy and the other kaolin-associated minerals, as well as the variations in the crystallinity of kaolinite. The mineral maps enabled the

  4. Generalized Test Plan for the Vitrification of Simulated High-Level -Waste Calcine in the Idaho National Laboratory's Bench -Scale Cold Crucible Induction Melter

    International Nuclear Information System (INIS)

    Maio, Vince

    2011-01-01

    This Preliminary Idaho National Laboratory (INL) Test Plan outlines the chronological steps required to initially evaluate the validity of vitrifying INL surrogate (cold) High-Level-Waste (HLW) solid particulate calcine in INL's Cold Crucible Induction Melter (CCIM). Its documentation and publication satisfies interim milestone WP-413-INL-01 of the DOE-EM (via the Office of River Protection) sponsored work package, WP 4.1.3, entitled 'Improved Vitrification' The primary goal of the proposed CCIM testing is to initiate efforts to identify an efficient and effective back-up and risk adverse technology for treating the actual HLW calcine stored at the INL. The calcine's treatment must be completed by 2035 as dictated by a State of Idaho Consent Order. A final report on this surrogate/calcine test in the CCIM will be issued in May 2012-pending next fiscal year funding In particular the plan provides; (1) distinct test objectives, (2) a description of the purpose and scope of planned university contracted pre-screening tests required to optimize the CCIM glass/surrogate calcine formulation, (3) a listing of necessary CCIM equipment modifications and corresponding work control document changes necessary to feed a solid particulate to the CCIM, (4) a description of the class of calcine that will be represented by the surrogate, and (5) a tentative tabulation of the anticipated CCIM testing conditions, testing parameters, sampling requirements and analytical tests. Key FY -11 milestones associated with this CCIM testing effort are also provided. The CCIM test run is scheduled to be conducted in February of 2012 and will involve testing with a surrogate HLW calcine representative of only 13% of the 4,000 m3 of 'hot' calcine residing in 6 INL Bin Sets. The remaining classes of calcine will have to be eventually tested in the CCIM if an operational scale CCIM is to be a feasible option for the actual INL HLW calcine. This remaining calcine's make-up is HLW containing

  5. Research about the pozzolanic activity of waste materials from calcined clay

    Directory of Open Access Journals (Sweden)

    Sánchez de Rojas, M. I.

    2001-03-01

    Full Text Available To recycle and reutilise waste materials and find definite applications for their use, it is necessary to have a deep knowledge of them. The aim of this study is to study the possibility of using waste materials from calcined clay, actually ceramic tile, once crushed and grounded, as pozzolanic material. For this purpose, different tests are carried out in order to establish the pozzolanic activity of this material. At the same time, these results are compared to those of other industrial by-products, fly ash and silica fume, which are pozzolanic materials usually employed to elaborate mortars and concretes.

    Para llevar a cabo labores encaminadas al reciclado y revalorización de residuos es necesario un conocimiento profundo de los mismos, de forma que se busquen aplicaciones concretas de uso. El objetivo de este estudio es investigar la posibilidad de utilizar materiales de desecho procedentes de arcilla cocida, concretamente teja cerámica, una vez triturada y molida, como puzolana. Para ello, se efectúan diferentes ensayos dirigidos a establecer la actividad puzolanica del material. A su vez, estos resultados son comparados con otros residuos industriales, ceniza volante y humo de sílice, habituales en la elaboración de morteros y hormigones.

  6. Stabilization of lead and copper contaminated firing range soil using calcined oyster shells and fly ash.

    Science.gov (United States)

    Moon, Deok Hyun; Park, Jae-Woo; Cheong, Kyung Hoon; Hyun, Seunghun; Koutsospyros, Agamemnon; Park, Jeong-Hun; Ok, Yong Sik

    2013-12-01

    A stabilization/solidification treatment scheme was devised to stabilize Pb and Cu contaminated soil from a firing range using renewable waste resources as additives, namely waste oyster shells (WOS) and fly ash (FA). The WOS, serving as the primary stabilizing agent, was pre-treated at a high temperature to activate quicklime from calcite. Class C FA was used as a secondary additive along with the calcined oyster shells (COS). The effectiveness of the treatment was evaluated by means of the toxicity characteristic leaching procedure (TCLP) and the 0.1 M HCl extraction tests following a curing period of 28 days. The combined treatment with 10 wt% COS and 5 wt% FA cause a significant reduction in Pb (>98 %) and Cu (>96 %) leachability which was indicated by the results from both extraction tests (TCLP and 0.1 M HCl). Scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) analyses are used to investigate the mechanism responsible for Pb and Cu stabilization. SEM-EDX results indicate that effective Pb and Cu immobilization using the combined COS-FA treatment is most probably associated with ettringite and pozzolanic reaction products. The treatment results suggest that the combined COS-FA treatment is a cost effective method for the stabilization of firing range soil.

  7. Heavy metal stabilization in contaminated soil by treatment with calcined cockle shell.

    Science.gov (United States)

    Islam, Mohammad Nazrul; Taki, Golam; Nguyen, Xuan Phuc; Jo, Young-Tae; Kim, Jun; Park, Jeong-Hun

    2017-03-01

    In several previous studies, the efficacy of various liming waste materials on the immobilization of heavy metals has been tested and it was found that soils contaminated with heavy metals can be stabilized using this technique. Since lime (CaO) has been identified as the main phase of calcined cockle shell (CCS), it was hypothesized that CCS could be used as a soil amendment to immobilize heavy metals in soil. However, to date, no studies have been conducted using CCS. In this study, the effectiveness of CCS powder on the immobilization of Cd, Pb, and Zn in mine tailing soil was evaluated. After 28 days of incubation, the treated soil samples were exposed to weathering (four cycles of freezing-thawing and four cycles of wetting-drying) for 8 days before being subjected to a leaching test. The results of this study revealed that the soil pH increased from 7.5 to 12.2 with the addition of 5% CCS. A similar soil pH was obtained when the soil was amended with 5% pure CaO. By leaching with 0.1 M HCl, extracted Cd, Pb, and Zn were reduced by up to 85, 85, and 91%, respectively. Therefore, CCS is suggested as a low-cost lime-based soil amendment for stabilizing heavy metals in abandoned mining sites.

  8. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    KAUST Repository

    Yoon, Seyoon

    2014-06-01

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g -1 and 257 mg g-1, respectively) of the CLDHs were comparable to the theoretical capacity of Friedel\\'s salt (2 mol mol-1 or 121 mg g-1), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. © 2014 Published by Elsevier B.V. All rights reserved.

  9. Thermokinetic study of the rehydration process of a calcined MgAl-layered double hydroxide.

    Science.gov (United States)

    Pfeiffer, Heriberto; Lima, Enrique; Lara, Víctor; Valente, Jaime S

    2010-03-16

    The rehydration process of a calcined MgAl-layered double hydroxide (LDH) with a Mg/Al molar ratio of 3 was systematically analyzed at different temperatures and relative humidity. Qualitative and quantitative experiments were done. In the first set of samples, the temperature or the relative humidity was varied, fixing the second variable. Both adsorption and absorption phenomena were present; absorption process was associated to the LDH regeneration. Of course, in all cases the LDH regeneration was confirmed by other techniques such as TGA, solid state NMR, and SAXS. In the second set of experiments, a kinetic analysis was performed, the results allowed to obtain different activation enthalpies for the LDH regeneration as a function of the relative humidity. The activation enthalpies varied from 137.6 to 83.3 kJ/mol as a function of the relative humidity (50 and 80%, respectively). All these experiments showed that LDH regeneration is highly dependent on the temperature and relative humidity.

  10. Behavior of radioactive iodine and technetium in the spray calcination of high-level waste

    Science.gov (United States)

    Knox, C. A.; Farnsworth, R. K.

    1981-08-01

    The Remote Laboratory-Scale Waste Treatment Facility (RLSWTF) was designed and built as a part of the High-Level Waste Immobilization Program (now the High-Level Waste Process Development Program) at the Pacific Northwest Laboratory. In facility, installed in a radiochemical cell, is described in which installed in a radiochemical cell is described in which small volumes of radioactive liquid wastes can be solidified, the process off gas can be analyzed, and the methods for decontaminating this off gas can be tested. During the spray calcination of commercial high-level liquid waste spiked with Tc-99 and I-131 and 31 wt% loss of I-131 past the sintered-metal filters. These filters and venturi scrubber were very efficient in removing particulates and Tc-99 from the the off-gas stream. Liquid scrubbers were not efficient in removing I-131 as 25% of the total lost went to the building off-gas system. Therefore, solid adsorbents are needed to remove iodine. For all future operations where iodine is present, a silver zeolite adsorber is to be used.

  11. Effects of Calcined clay minerals and Silica fume on the compressive strength of concrete

    Directory of Open Access Journals (Sweden)

    Abolfazl Soltani

    2017-05-01

    Full Text Available Pozzolanic materials are well known as potential replacements for cement manufacturing in order to increase compressive strength and improve durability of concrete in different environments and leading to save energy particularly reducing global warming effect. The present study reveals the effect of calcined clay minerals as natural pozzolanic material, separately and in combination with and without silica fume. To achieve this aim, 15 mixed designs with a constant water to cementitious ratio of  0.38 is made. In six mixed designs only metakaolin, zeolite or silica fume  and in eight other designs metakaolin and silica fume or zeolite and silica fume have been combined. Mixes containing metakaolin or zeolite with ratio of 10 or 20 percent and silica fume with 7 or 10 percent show significant increasing in compressive strength and improving durability, being valuable replacement for cement (in percentages. In particular, the best practice is attributed to the age of 28 days for compressive strength the replacement of the composition is 10% zeolite with 7% of silica fume and for electrical resistance the replacement of the composition is 10% zeolite with 7% of silica fume.

  12. Production of hydrogen through the carbonation-calcination reaction applied to CH4/CO2 mixtures

    International Nuclear Information System (INIS)

    Barelli, L.; Bidini, G.; Corradetti, A.; Desideri, U.

    2007-01-01

    The production of hydrogen combined with carbon capture represents a possible option for reducing CO 2 emissions in atmosphere and anthropogenic greenhouse effect. Nowadays the worldwide hydrogen production is based mainly on natural gas reforming, but the attention of the scientific community is focused also on other gas mixtures with significant methane content. In particular mixtures constituted mainly by methane and carbon dioxide are extensively used in energy conversion applications, as they include land-fill gas, digester gas and natural gas. The present paper addresses the development of an innovative system for hydrogen production and CO 2 capture starting from these mixtures. The plant is based on steam methane reforming, coupled with the carbonation and calcination reactions for CO 2 absorption and desorption, respectively. A thermodynamic approach is proposed to investigate the plant performance in relation to the CH 4 content in the feeding gas. The results suggest that, in order to optimize the hydrogen purity and the efficiency, two different methodologies can be adopted involving both the system layout and operating parameters. In particular such methodologies are suitable for a methane content, respectively, higher and lower than 65%

  13. Regeneration of Waste Edible Oil by the Use of Virgin and Calcined Magnesium Hydroxide as Adsorbents.

    Science.gov (United States)

    Ogata, Fumihiko; Kawasaki, Naohito

    2016-01-01

    In this study, we prepared virgin (S, L) and calcined (S-380, S-1000, L-380, L-1000) magnesium hydroxide for regeneration of waste edible oil. Deterioration of soybean oil, rapeseed oil, and olive oil was achieved by heat and aeration treatment. The properties of the different adsorbents were investigated using specific surface area measurements, scanning electron microscopy, X-ray diffraction analysis, thermogravimetric-differential thermal analysis, and surface pH measurement. Moreover, the relationship between the changes in acid value (AV) and carbonyl value (CV) and the adsorbent properties were evaluated. The specific surface areas of S-380 and L-380 were greater than that of other adsorbents. In addition, the XRD results show that S-380 and L-380 contain both magnesium hydroxide and magnesium oxide structures. The decreases in AV and CV using S-380 and L-380 were greater than achieved using other adsorbents. The correlation coefficients between the decrease in AV and CV and specific surface area were 0.947 for soybean oil, 0.649 for rapeseed oil, and 0.773 for olive oil, respectively. The results obtained in this study suggest that a physical property of the adsorbent, namely specific surface area, was primarily responsible for the observed decreases in AV and CV. Overall, the results suggest that S-380 and L-380 are useful for the regeneration of waste edible oil.

  14. Adsorption of methyl orange from aqueous solution onto calcined Lapindo volcanic mud

    International Nuclear Information System (INIS)

    Jalil, Aishah A.; Triwahyono, Sugeng; Adam, S. Hazirah; Rahim, N. Diana; Aziz, M. Arif A.; Hairom, N. Hanis H.; Razali, N. Aini M.; Abidin, Mahani A.Z.; Mohamadiah, M. Khairul A.

    2010-01-01

    In this study, calcined Lapindo volcanic mud (LVM) was used as an adsorbent to remove an anionic dye, methyl orange (MO), from an aqueous solution by the batch adsorption technique. Various conditions were evaluated, including initial dye concentration, adsorbent dosage, contact time, solution pH, and temperature. The adsorption kinetics and equilibrium isotherms of the LVM were studied using pseudo-first-order and -second-order kinetic equations, as well as the Freundlich and Langmuir models. The experimental data obtained with LVM fits best to the Langmuir isotherm model and exhibited a maximum adsorption capacity (q max ) of 333.3 mg g -1 ; the data followed the second-order equation. The intraparticle diffusion studies revealed that the adsorption rates were not controlled only by the diffusion step. The thermodynamic parameters, such as the changes in enthalpy, entropy, and Gibbs free energy, showed that the adsorption is endothermic, random and spontaneous at high temperature. The results indicate that LVM adsorbs MO efficiently and could be utilized as a low-cost alternative adsorbent for the removal of anionic dyes in wastewater treatment.

  15. An acetylcholinesterase biosensor based on graphene-gold nanocomposite and calcined layered double hydroxide.

    Science.gov (United States)

    Zhai, Chen; Guo, Yemin; Sun, Xia; Zheng, Yuhe; Wang, Xiangyou

    2014-05-10

    In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu-Mg-Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene-gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene-gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150μg/L. The detection limit for chlorpyrifos was 0.05μg/L. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Environmental assessment: Closure of the Waste Calcining Facility (CPP-633), Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    1996-07-01

    The U.S. Department of Energy (DOE) proposes to close the Waste Calcining Facility (WCF). The WCF is a surplus DOE facility located at the Idaho Chemical Processing Plant (ICPP) on the Idaho National Engineering Laboratory (INEL). Six facility components in the WCF have been identified as Resource Conservation and Recovery Ace (RCRA)-units in the INEL RCRA Part A application. The WCF is an interim status facility. Consequently, the proposed WCF closure must comply with Idaho Rules and Standards for Hazardous Waste contained in the Idaho Administrative Procedures Act (IDAPA) Section 16.01.05. These state regulations, in addition to prescribing other requirements, incorporate by reference the federal regulations, found at 40 CFR Part 265, that prescribe the requirements for facilities granted interim status pursuant to the RCRA. The purpose of the proposed action is to reduce the risk of radioactive exposure and release of hazardous constituents and eliminate the need for extensive long-term surveillance and maintenance. DOE has determined that the closure is needed to reduce potential risks to human health and the environment, and to comply with the Idaho Hazardous Waste Management Act (HWMA) requirements

  17. Surface modification of calcined kaolin with toluene diisocyanate based on high energy ball milling

    International Nuclear Information System (INIS)

    Yuan, Yongbing; Chen, Hongling; Lin, Jinbin; Ji, Yan

    2013-01-01

    The surface of calcined kaolin particle was modified with toluene diisocyanate (TDI) by using high energy ball milling. The prepared hybrids were characterized by FT-IR, MAS NMR, thermal analysis (TGA-DSC), static water contact angle (CA), apparent viscosity and transmission electron microscopy (TEM). FT-IR and MAS NMR spectra demonstrated that TDI molecules were chemically anchored to kaolin surface after modification. The results of thermal analysis showed that the maximum grafting ratio reached up to 446.61% when the mass ratio of TDI/kaolin was 0.5:1.0, and CA measurements revealed that the resultant hybrids exhibited strong hydrophobicity (148.82°). Apparent viscosity and TEM were employed to examine the dispersion properties of blank and modified kaolin particles in poly (dimenthylsiloxane) matrix. The results illustrated that the dispersion stability depended strongly on the grafting ratio of TDI, neither too low nor too high achieved uniform and stable dispersion, and the favorable grafting ratio was obtained when the mass ratio of TDI/kaolin was 0.2:1.0. Further modification of TDI/kaolin (mass ration of TDI/kaolin, 1.0:1.0) particles with bis(aminopropyl)-terminated-poly(dimethylsiloxane) (APS) was also investigated. TEM evidenced that the dispersion properties of the obtained TDI/APS/kaolin particles were remarkably improved in octamethyl cyclotetrasiloxane compared with the original TDI/kaolin particles.

  18. Surface modification of calcined kaolin with toluene diisocyanate based on high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Yongbing; Chen, Hongling, E-mail: hlchen@njut.edu.cn; Lin, Jinbin; Ji, Yan

    2013-11-01

    The surface of calcined kaolin particle was modified with toluene diisocyanate (TDI) by using high energy ball milling. The prepared hybrids were characterized by FT-IR, MAS NMR, thermal analysis (TGA-DSC), static water contact angle (CA), apparent viscosity and transmission electron microscopy (TEM). FT-IR and MAS NMR spectra demonstrated that TDI molecules were chemically anchored to kaolin surface after modification. The results of thermal analysis showed that the maximum grafting ratio reached up to 446.61% when the mass ratio of TDI/kaolin was 0.5:1.0, and CA measurements revealed that the resultant hybrids exhibited strong hydrophobicity (148.82°). Apparent viscosity and TEM were employed to examine the dispersion properties of blank and modified kaolin particles in poly (dimenthylsiloxane) matrix. The results illustrated that the dispersion stability depended strongly on the grafting ratio of TDI, neither too low nor too high achieved uniform and stable dispersion, and the favorable grafting ratio was obtained when the mass ratio of TDI/kaolin was 0.2:1.0. Further modification of TDI/kaolin (mass ration of TDI/kaolin, 1.0:1.0) particles with bis(aminopropyl)-terminated-poly(dimethylsiloxane) (APS) was also investigated. TEM evidenced that the dispersion properties of the obtained TDI/APS/kaolin particles were remarkably improved in octamethyl cyclotetrasiloxane compared with the original TDI/kaolin particles.

  19. Phase and morphology evolution of (Na1-xKxNbO3 powders related to calcinations and K2CO3 content

    Directory of Open Access Journals (Sweden)

    Steven J. Milne

    2007-03-01

    Full Text Available Sodium-potassium niobate ((Na1-xKxNbO3 powders with x = 0.2, 0.4, 0.6 and 0.8 were prepared following the conventional mixed oxide method and characterized by TG-DTA, XRD and SEM techniques.The effects of calcination temperature, dwell time and K2CO3 content on phase formation behavior and morphology of the powders were investigated. The calcination temperature and dwell time were found tohave a pronounced effect on the phase formation of the calcined sodium-potassium niobate powders. It was found that the crystallized phase depended on calcination conditions. The high calcination temperature andlong dwell time clearly favored particle growth and the formation of large and hard agglomerates. All the (Na1-xKxNbO3 powders showed a similar orthorhombic phase structure. The K2CO3 content significantlyaffected the calcination temperature and particle size and shape. Large particle size, cubic shape and a lower calcined condition were observed in (Na1-xKxNbO3 powder with low K2CO3 content (x = 0.2.

  20. A mineralogical investigation of a refractory gold ore, and of a sulphide concentrate and calcined tailing from that ore

    International Nuclear Information System (INIS)

    Ollila, J.T.

    1983-01-01

    This report covers an investigation into the manner of occurrence of gold in an old mine dump of calcined tailings at the Fairview Mine. Previous investigations had not revealed the whereabouts of the gold still present in this dump, which amounts to between 10 and 12p.p.m. In the present investigation, in which heavy-liquid separation was combined with X-ray, microscope, and electron-microprobe investigations, it was found that a significant proportion of the gold is adsorbed on carbon, and that a smaller proportion is present in pyrite that escaped complete calcination. An enigma is the occurrence of ferrosilicon, some of which contains gold. Although this study produced new information, a more detailed quantitative investigation is required in which an image analyser should be used to provide reliable quantitative data

  1. Synthesis and characterization of ZSM-5 and calcined kaolin evaluation using the content of structure-directing

    International Nuclear Information System (INIS)

    Rodrigues, J.J.; Silva, V.J. da; Rodrigues, M.G.F.

    2012-01-01

    This study aims to evaluate the effect of the structure-directing content, tetrapropylammonium bromide, on the structural and morphological characteristics of ZSM-5 zeolite obtained using calcined kaolin as silicon and aluminum. The samples were characterized by XRD, EDX, SEM and Physics Adsorption N 2 . Trough X ray diffraction patterns was possible to observed the formation of the structure of ZSM-5 with intense peaks and well-defined characteristic of crystalline. The micrographs showed that the samples consist of agglomerates and/or aggregates of particles characteristic of the MFI structure typical of ZSM-5 zeolite. And through the adsorption-desorption isotherms physical N2 was possible to observe that the samples show hysteresis type I typical of microporous materials with specific surface areas of 218 and 222 m 2 /g. Therefore, the use of calcined kaolin to obtain ZSM-5 zeolite was effective. (author)

  2. The Effect of Calcination Temperature on the Performance of TiO2 Aggregates-based Dye Solar Cells (DSCs)

    International Nuclear Information System (INIS)

    Siti Nur Azella Zaine; Norani Muti Mohamed; Mohamad Azmi Bustam

    2011-01-01

    In this paper, the effect of calcination temperature on the physicochemical properties of synthesized TiO 2 aggregates and their influence on overall light conversion efficiency of dye solar cell (DSc) were investigated. Samples of TiO 2 aggregates (mean size of 0.45 μm) composing of nano crystallites (10-40 nm) were synthesized through hydrolysis of dilute titanium alkoxide in ethanol. Phase and microstructure of the TiO 2 obtained have been characterized using FESEM, XRD and UV-Vis spectroscopy. I-V characterization shows that TiO 2 aggregates based DSC demonstrated better performance compared to nanoparticles (P-25)-based DSC. The optimum calcination temperature was found to be about 500 degree Celsius with efficiency of 4.456 %, which is 30 % increment compared to P-25-based DSC under the same condition. (author)

  3. Comparative studies on physico-mechanical properties of composite materials of low density polyethylene and raw/calcined kaolin

    Directory of Open Access Journals (Sweden)

    Amit Mallik

    2015-06-01

    Full Text Available The paper describes the preparation of the composite materials of low density polyethylene (LDPE as the base mixed separately with raw kaolin and the same calcined at 800 °C under the same variation in weight percentage using single-screw extruder and a mixing machine operated at a temperature between 190 and 200 °C. Some of the mechanical and physical properties such as Young's modulus, elongation at break, shore hardness and water absorption were determined at different weight fractions of filler (0, 2, 7, 10 and 15%. It was found that the addition of filler increases the mechanical properties. Absorption test was done in water at different immersion times for different composites. The degree of water absorption of composite materials was found to decrease with increasing wt% of kaolin filler (0–15% according to Fick's law. Calcined kaolin produces better mechanical properties than raw kaolin.

  4. Effect of K3PO4 addition as sintering inhibitor during calcination of Y2O3 nanoparticles

    Science.gov (United States)

    Soga, K.; Okumura, Y.; Tsuji, K.; Venkatachalam, N.

    2009-11-01

    Erbium-doped yttrium oxide nanoparticle is one of the most important for fluorescence bioimaging under near infrared excitation. Particle size of it below 100 nm is an important requirement for a cellular bioimaging. However, the synthesis with such small particles is difficult at the calcination temperature above 1200 °C due to the sintering and crystal growth of the particles. In this study, yttrium oxide nanoparticles with average size of 30 nm were successfully synthesized by using K3PO4 as a sintering inhibitor during the calcination. A single phase of cubic Y2O3 as the resultant material was confirmed by XRD, which was also confirmed to emit a bright upconversion emission under 980-nm excitation. Improvement of chemical durability due to the introduction of phosphate group on the surface of the Y2O3 particles is also reported.

  5. Effect of the calcining temperature on the porosity of the titanium dioxide powders obtained by Polymeric Precursor Method

    International Nuclear Information System (INIS)

    Silva, D.W.; Granado, S.R.; Ciola, R.A.; Cavalheiro, A.A.

    2011-01-01

    Ceramics materials obtained by Polymeric Precursor Method exhibit mechanisms of the pore formation and elimination dependents on the decomposition kinetics of the residual organic matter of the polyester. The mechanism of pore elimination seems to occur by disrupting of the wall among the pores because it leads to the consequent pore coalescence and increasing in pore volume, which posses higher pore diameters. In this case, it was observed that the porosity decreasing occurs by pore wall moving after that the residual organic matter is eliminated from the pore inside. The pore diameter associated to the highest volume desorption occurred for the material obtained after calcining at 450°C is approximately 1,7 nm, what seems to be related to the amorphous carbon accumulated inside the pores, once that the pore volume decreases more effectively for the material obtained by calcining at 550°C, making the maximum volume situates at 2,0 nm. (author)

  6. The influence of calcination temperature on catalytic activities in a Co based catalyst for CO2 dry reforming

    International Nuclear Information System (INIS)

    Song, Sang-Hoon; Son, Ju-Hee; Budiman, Anatta Wahyu; Choi, Myoung-Jae; Chang, Tae-Sun; Shin, Chae-Ho

    2014-01-01

    The carbon dioxide dry reforming of methane (CDR) reaction could be thermodynamically favored in the range of 800 to 1,000 .deg. C. However, the catalyst in this reaction should be avoided at the calcination temperature over 800 .deg. C since strong metal support interaction (SMSI) in this temperature range can decrease activity due to loss of active sites. Therefore, we focused on optimizing the temperature of pretreatment and a comparison of surface characterization results for CDR. Results related to metal sintering over support, re-dispersion by changing of particle size of metal-support, and strong metal support interaction were observed and confirmed in this work. In our conclusion, optimum calcination temperature for a preparation of catalyst was proposed that 400 .deg. C showed a higher and more stable catalytic activity without changing of support characteristics

  7. Evaluation of kaolinite clays of Moa for the production of cement based clinker-calcined clay-limestone (LC3

    Directory of Open Access Journals (Sweden)

    Roger S. Almenares-Reyes

    2016-12-01

    Full Text Available Clay materials from two outcrops of the Moa region were analyzed to determine their potential use as supplementary cementitious material in the production of ternary cements based on limestone-calcined clay. The clays were characterized by atomic absorption spectroscopy (EAA, X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR and thermogravimetric analysis (ATG. These methods revealed high aluminum in clays, moderate kaolinite content, a disordered structure and the presence of impurities. The solubility of aluminum and silicon in alkali and the compressive strength of LC3 systems is proportional to their content in clay, being higher for the one with higher kaolinite content and greater structural disorder (outcrop D1, although the clay of both outcrops may constitute supplementary cementitious materials in the production of ternary cements based clinker-calcined clay-limestone. The suitable thermal activation range for both clays is between 650 ° C and 850 ° C.

  8. Characterization and use of in natura and calcined rice husks for biosorption of heavy metals ions from aqueous effluents

    Directory of Open Access Journals (Sweden)

    M. G. A. Vieira

    2012-09-01

    Full Text Available Heavy metal removal by adsorption using rice husks as a bioadsorbent was evaluated as an alternative for wastewater treatment. Batch equilibrium experiments and kinetic sorption studies were performed using monocomponent solutions of Ni(II, Cd(II, Zn(II, Pb(II and Cu(II in surface samples of in natura(RH and calcined rice husks (RHA. RHA showed higher potential for removing lead and copper. Experimental data for adsorption isotherms of lead and copper were adjusted by Langmuir, Freundlich and Dubinin-Radushkevick (D-R models, being better represented by the Langmuir model. The calcination of RH increased its surface area, improving its adsorption properties. From a morphological analysis obtained by SEM and diffraction patterns (XRD, a longitudinal fibrous and amorphous structure was observed for RH. TGA resultsindicated a total mass loss of around 60% for RH and 24.5% for RHA.

  9. Silica Supported Platinum Catalysts for Total Oxidation of the Polyaromatic Hydrocarbon Naphthalene: An Investigation of Metal Loading and Calcination Temperature

    Directory of Open Access Journals (Sweden)

    David R. Sellick

    2015-04-01

    Full Text Available A range of catalysts comprising of platinum supported on silica, prepared by an impregnation method, have been studied for the total oxidation of naphthalene, which is a representative Polycyclic Aromatic Hydrocarbon. The influence of platinum loading and calcination temperature on oxidation activity was evaluated. Increasing the platinum loading up to 2.5 wt.% increased the catalyst activity, whilst a 5.0 wt.% catalyst was slightly less active. The catalyst containing the optimum 2.5 wt.% loading was most active after calcination in air at 550 °C. Characterisation by carbon monoxide chemisorption and X-ray photoelectron spectroscopy showed that low platinum dispersion to form large platinum particles, in combination with platinum in metallic and oxidised states was important for high catalyst activity. Catalyst performance improved after initial use in repeat cycles, whilst there was slight deactivation after prolonged time-on-stream.

  10. Application of the Rietveld method in powders of strontium-doped lanthanum manganite calcined in different temperatures

    International Nuclear Information System (INIS)

    Chiba, R.; Vargas, R.A.; Martinez, L.G.; Andreoli, M.; Seo, E.S.M.

    2010-01-01

    The strontium-doped lanthanum manganite (LSM) is a ceramic material used as cathode in device called High Temperature Solid Oxide Fuel Cell. In this work, the LSM was synthesized by the citrate technique with the objective to get powders without the formation of secondary phases, such as lanthanum oxide and the lanthanum hydroxide, harmful for the functional performance of the device. The definitive calcination temperatures had been 700, 900 and 1100 deg C, due the decomposition of the polymeric precursors to present stabilization from 480 deg C. The analysis by X-ray diffraction of the calcined powders in different temperatures shows the formation only of phase LSM of hexagonal crystalline structure, type pseudo-perovskite. Using the refinement of Rietveld was determined the parameters and volumes of unity cells, atomic positions and occupations. These results confirm that the chemical compositions obtained are similar to the nominal. (author)

  11. Synthesis of octahedral like Cu-BTC derivatives derived from MOF calcined under different atmosphere for application in CO oxidation

    Science.gov (United States)

    Yang, Yiqiong; Dong, Han; Wang, Yin; He, Chi; Wang, Yuxin; Zhang, Xiaodong

    2018-02-01

    A series of octahedral structure Cu-BTC derivatives were successfully achieved through direct calcination of copper based metal organic framework Cu-BTC under different atmosphere (CO reaction gas, oxidizing gas O2, reducing gas H2, inert gas Ar). The Cu-BTC derivatives were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), laser Raman spectroscopy (LRS), N2 adsorption-desorption isotherm, element analysis, H2-temperature program reduction (H2-TPR) and X-ray photoelectron spectroscopic (XPS). It is found that Cu-BTC derivative derived from MOF calcined under reaction gas/O2 (Cu-BTC-CO/Cu-BTC-O) only retain Cu2O and CuO species. In addition, a weak Cu-BTC structure and Cu particles were observed on Cu-BTC derivative derived from MOF calcined under H2 (Cu-BTC-H). Obviously differently, Cu-BTC derivative derived from MOF calcined under Ar (Cu-BTC-Ar) still retains good MOF structure. The catalytic performance for CO oxidation over Cu-BTC derivatives was studied. It was found that Cu-BTC-CO showed a smaller specific surface area (8.0 m2/g), but presented an excellent catalytic performance, long-term stability and cycling stability with a complete CO conversion temperature (T100) of 140 °C, which was ascribed to the higher Cu2O/CuO ratio, good low temperature reduction behavior and a high quantity of surface active oxygen species.

  12. Decomposition of methane over alumina supported Fe and Ni–Fe bimetallic catalyst: Effect of preparation procedure and calcination temperature

    Directory of Open Access Journals (Sweden)

    A.S. Al-Fatesh

    2018-02-01

    Full Text Available Catalytic decomposition of methane has been studied extensively as the production of hydrogen and formation of carbon nanotube is proven crucial from the scientific and technological point of view. In that context, variation of catalyst preparation procedure, calcination temperature and use of promoters could significantly alter the methane conversion, hydrogen yield and morphology of carbon nanotubes formed after the reaction. In this work, Ni promoted and unpromoted Fe/Al2O3 catalysts have been prepared by impregnation, sol–gel and co-precipitation method with calcination at two different temperatures. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption, temperature programmed reduction (TPR and thermogravimetric analysis (TGA techniques. The catalytic activity was tested for methane decomposition reaction. The catalytic activity was high when calcined at 500 °C temperature irrespective of the preparation method. However while calcined at high temperature the catalyst prepared by impregnation method showed a high activity. It is found from XRD and TPR characterization that disordered iron oxides supported on alumina play an important role for dissociative chemisorptions of methane generating molecular hydrogen. The transmission electron microscope technique results of the spent catalysts showed the formation of carbon nanotube which is having length of 32–34 nm. The Fe nanoparticles are present on the tip of the carbon nanotube and nanotube grows by contraction–elongation mechanism. Among three different methodologies impregnation method was more effective to generate adequate active sites in the catalyst surface. The Ni promotion enhances the reducibility of Fe/Al2O3 oxides showing a higher catalytic activity. The catalyst is stable up to six hours on stream as observed in the activity results.

  13. Operation of a 25 kWth Calcium Looping Pilot-plant with High Oxygen Concentrations in the Calciner.

    Czech Academy of Sciences Publication Activity Database

    Erans, M.; Jeremiáš, Michal; Manovic, V.; Anthony, E.J.

    2017-01-01

    Roč. 128, 25 OCT (2017), č. článku e56112. ISSN 1940-087X Grant - others:RFCS(XE) RFCR-CT-2014-00007 Institutional support: RVO:67985858 Keywords : calcium looping * CO2 capture * oxy- fuel calcination Subject RIV: JE - Non-nuclear Energetics, Energy Consumption ; Use OBOR OECD: Energy and fuel s Impact factor: 1.232, year: 2016

  14. Sulfation of CaO particles in a carbonation/calcination loop to capture CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Grasa, G.S.; Alonso, M.; Abanades, J.C. [CSIC, Zaragoza (Spain)

    2008-03-15

    CaO is being proposed as a regenerable sorbent of CO{sub 2} via a carbonation/calcination loop. It is well known that natural sorbents lose their capacity to capture CO{sub 2} with the number of cycles due to textural degradation. In coal combustion systems, reaction with the SO{sub 2} present in flue gases also causes sorbent deactivation. This work investigates the effect of partial sorbent sulfation on the amount of CaO used in systems where both carbonation and sulfation reactions are competing. We have found that SO{sub 2} reacts with the deactivated CaO resulting from repetitive calcination/carbonation reactions. Therefore, the deactivation of CaO as a result of the presence of SO{sub 2} is lower than one would expect if one assumes that SO{sub 2} reacts only with active CaO. This work shows that changes in the texture of the sorbent due to repetitive carbonation/calcination cycles tend to increase the sulfation capacity of the sorbents tested. This suggests that the purge of deactivated CaO obtained from a CO{sub 2} capture loop could be a more effective sorbent of SO{sub 2} than fresh CaO.

  15. Feasibility of sulfate-calcined eggshells for removing pathogenic bacteria and antibiotic resistance genes from landfill leachates.

    Science.gov (United States)

    Ye, Mao; Sun, Mingming; Chen, Xu; Feng, Yanfang; Wan, Jinzhong; Liu, Kuan; Tian, Da; Liu, Manqiang; Wu, Jun; Schwab, Arthur P; Jiang, Xin

    2017-05-01

    High abundance of human pathogen and antibiotic resistance genes (ARGs) in landfill leachate has become an emerging threat against human health. Therefore, sulfate- and calcination-modified eggshells as green agricultural bioresource were applied to test the feasibility of removing pathogenic bacteria and ARGs from leachate. The highest removal of Escherichia coli (E. coil) and gentamycin resistant gene (gmrA) from artificial contaminated landfill leachate was achieved by the application of eggshell with combined treatment of sulfate and calcination. The 16S and gmrA gene copies of E. coil declined significantly from 1.78E8±8.7E6 and 4.12E8±5.9E6 copies mL -1 to 1.32E7±2.6E6 and 2.69E7±7.2E6 copies mL -1 , respectively, within 24h dynamic adsorption equilibrium process (ppathogenic bacteria and ARGs (tet, sul, erm, qnr, and ampC) indicated its great efficiency to purify landfill leachates. This study demonstrated that sulfate-calcined eggshells can be an environmentally-friendly and highly efficient bioadsorbent to the management of reducing dissemination risk of pathogen and ARGs in landfill leachate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Atmospheric pressure plasma assisted calcination by the preparation of TiO2 fibers in submicron scale

    Science.gov (United States)

    Medvecká, Veronika; Kováčik, Dušan; Zahoranová, Anna; Černák, Mirko

    2018-01-01

    Atmospheric pressure plasma assisted calcination by the preparation of TiO2 submicron fibers as a low-temperature alternative to the conventional thermal annealing was studied. A special type of dielectric barrier discharge was used for plasma treatment of hybrid titanium butoxide/polyvinylpyrrolidone (Ti(Bu)/PVP) fibers prepared by forcespinning to decompose and oxidize the base polymer and precursor. The obtained fibers were characterized by changes in chemical bonds on the surface using Fourier Transform Infrared Spectroscopy (FTIR), chemical composition by using Energy-Dispersive X-Ray Spectroscopy (EDX), X-ray Photoelectron Spectroscopy (XPS). The morphology of fibers was investigated by Scanning Electron Microscopy (SEM). A significant decrease of organic components was reached by short plasma exposure times less than 1 h. The obtained fibers exhibit a high surface porosity without degradation of the fibrous structure. The results obtained indicate that atmospheric pressure plasma assisted calcination can be a viable low-temperature, energy- and time-saving alternative or pre-treatment method for the conventional high-temperature thermal calcination.

  17. Effect of calcination temperature on formaldehyde oxidation performance of Pt/TiO2 nanofiber composite at room temperature

    Science.gov (United States)

    Xu, Feiyan; Le, Yao; Cheng, Bei; Jiang, Chuanjia

    2017-12-01

    Catalytic oxidation at room temperature over well-designed catalysts is an environmentally friendly method for the abatement of indoor formaldehyde (HCHO) pollution. Herein, nanocomposites of platinum (Pt) and titanium dioxide (TiO2) nanofibers with various phase compositions were prepared by calcining the electrospun TiO2 precursors at different temperatures and subsequently depositing Pt nanoparticles (NPs) on the TiO2 through a NaBH4-reduction process. The phase compositions and structures of Pt/TiO2 can be easily controlled by varying the calcination temperature. The Pt/TiO2 nanocomposites showed a phase-dependent activity towards the catalytic HCHO oxidation. Pt/TiO2 containing pure rutile phase showed enhanced activity with a turnover frequency (TOF) of 16.6 min-1 (for a calcination temperature of 800 °C) as compared to those containing the anatase phase or mixed phases. Density functional theory calculation shows that TiO2 nanofibers with pure rutile phase have stronger adsorption ability to Pt atoms than anatase phase, which favors the reduction of Pt over rutile phase TiO2, leading to higher contents of metallic Pt in the nanocomposite. In addition, the Pt/TiO2 with rutile phase possesses more abundant oxygen vacancies, which is conducive to the activation of adsorbed oxygen. Consequently, the Pt/rutile-TiO2 nanocomposite exhibited better catalytic activity towards HCHO oxidation at room temperature.

  18. Calcined Eggshell Waste for Mitigating Soil Antibiotic-Resistant Bacteria/Antibiotic Resistance Gene Dissemination and Accumulation in Bell Pepper.

    Science.gov (United States)

    Ye, Mao; Sun, Mingming; Feng, Yanfang; Li, Xu; Schwab, Arthur P; Wan, Jinzhong; Liu, Manqiang; Tian, Da; Liu, Kuan; Wu, Jun; Jiang, Xin

    2016-07-13

    The combined accumulation of antibiotics, heavy metals, antibiotic-resistant bacteria (ARB)/antibiotic resistance genes (ARGs) in vegetables has become a new threat to human health. This is the first study to investigate the feasibility of calcined eggshells modified by aluminum sulfate as novel agricultural wastes to impede mixed contaminants from transferring to bell pepper (Capsicum annuum L.). In this work, calcined eggshell amendment mitigated mixed pollutant accumulation in bell pepper significantly, enhanced the dissipation of soil tetracycline, sulfadiazine, roxithromycin, and chloramphenicol, decreased the water-soluble fractions of antibiotics, and declined the diversity of ARB/ARGs inside the vegetable. Moreover, quantitative polymerase chain reaction analysis detected that ARG levels in the bell pepper fruits significantly decreased to 10(-10) copies/16S copies, indicating limited risk of ARGs transferring along the food chain. Furthermore, the restoration of soil microbial biological function suggests that calcined eggshell is an environmentally friendly amendment to control the dissemination of soil ARB/ARGs in the soil-vegetable system.

  19. Effect of calcinations temperature on the luminescence intensity and fluorescent lifetime of Tb3+-doped hydroxyapatite (Tb-HA nanocrystallines

    Directory of Open Access Journals (Sweden)

    Hairong Yin

    2017-06-01

    Full Text Available Hydroxyapatite luminescent nanocrystallines doped with 6 mol.% Tb3+ (Tb-HA were prepared via chemical deposition method and calcined at different temperature, and the effects of calcinations temperature on the luminescence intensity and fluorescent lifetime were studied. TEM image of Tb-HA revealed that the shape of nanocrystallines changed from needle-like to short rod-like and sphere-like with the increase of calcinations temperature; while the particles sizes decreased from 190 nm to 110 nm. The crystallinity degree increased. The typical emission peaks attributed to Tb3+ ions were observed in emission spectra of 6 mol.% Tb-HA under 378 nm excitation. The luminescent intensity of Tb-HA, which showed the fluorescence quenching, firstly enhanced and then decreased at 700 °C; while the fluorescent lifetime increased firstly and then decreased after 600 °C. Furthermore, the ratio of intensity between 545 nm and 490 nm corresponding to electric-dipole and magnetic-dipole transition (IR: IO increases firstly and then decreases, which revealed that the proportion of substitute type and site of Ca2+ ions by Tb3+ ions were helpful to realize the substitute process and functional structure design.

  20. Oxidative desulfurization of benzothiophene and thiophene with WOx/ZrO2 catalysts: Effect of calcination temperature of catalysts

    International Nuclear Information System (INIS)

    Hasan, Zubair; Jeon, Jaewoo; Jhung, Sung Hwa

    2012-01-01

    Highlights: ► Oxidative desulfurization was studied with WO x /ZrO 2 calcined at different temp. ► The importance of the phases of zirconia and tungsten oxide was suggested. ► The catalyst was analyzed thoroughly with Raman and XRD techniques. ► The importance of electron density on S was confirmed with the kinetics of oxidation. - Abstract: Oxidative desulfurization (ODS) of model fuel containing benzothiophene (BT) or thiophene (Th) has been carried out with WO x /ZrO 2 catalyst, which was calcined at various temperatures. Based on the conversion of BT in the model fuel, it can be shown that the optimum calcination temperature of WO x /ZrO 2 catalyst is around 700 °C. The most active catalyst is composed of tetragonal zirconia (ZrO 2 ) with well dispersed polyoxotungstate species and it is necessary to minimize the contents of the crystalline WO 3 and monoclinic ZrO 2 for a high BT conversion. The oxidation rate was interpreted with the first-order kinetics, and it demonstrated the importance of electron density since the kinetic constant for BT was higher than that for Th even though the BT is larger than Th in size. A WO x /ZrO 2 catalyst, treated suitably, can be used as a reusable active catalyst in the ODS.

  1. Effects of Calcination Temperature on Preparation of Boron-Doped TiO2 by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Wenjie Zhang

    2012-01-01

    Full Text Available Boron-doped TiO2 photocatalyst was prepared by a modified sol-gel method. Being calcinated at temperatures from 300°C to 600°C, all the 3% B-TiO2 samples presented anatase TiO2 phase, and TiO2 crystallite sizes were calculated to be 7.6, 10.3, 13.6, and 27.3 nm, respectively. The samples were composed of irregular particles with rough surfaces in the size range within 3 μm. Ti atoms were in an octahedron skeleton and existed mainly in the form of Ti4+, while the Ti-O-B structure was the main boron existing form in the 3% B-TiO2 sample. When calcination temperature increased from 300°C to 600°C, specific surface area decreased sharply from 205.6 m2/g to 31.8 m2/g. The average pore diameter was 10.53 nm with accumulative pore volume of 0.244 mL/g for the 3% B-TiO2 sample calcinated at 400°C, which performed optimal photocatalytic degradation activity. After 90 min of UV-light irradiation, degradation rate of methyl orange was 96.7% on the optimized photocatalyst.

  2. Behavior of radioactive iodine and technetium in the spray calcination of high-level waste

    International Nuclear Information System (INIS)

    Knox, C.A.; Farnsworth, R.K.

    1981-08-01

    The Remote Laboratory-Scale Waste Treatment Facility (RLSWTF) was designed and built as a part of the High-Level Waste Immobilization Program (now the High-Level Waste Process Development Program) at the Pacific Northwest Laboratory. In this facility, which is installed in a radiochemical cell, small volumes of radioactive liquid wastes can be solidified, the process off gas can be analyzed, and the methods for decontaminating this off gas can be tested. Initial operations were completed with nonradioactive, simulated waste solutions (Knox, Siemens and Berger 1981). The first radioactive operations in this facility were performed with a simulated, commercial waste composition containing tracer levels of 99 Tc and 131 I. This report describes the facility and test operations and presents the results of the behavior of 131 I and 99 Tc during solidification of radioactive liquid wastes. During the spray calcination of commercial high-level liquid waste spiked with 99 Tc and 131 I, there was a 0.3 wt% loss of particulates, a 0.15 wt% loss of 99 Tc and a 31 wt% loss of 131 I past the sintered-metal filters. These filters and a venturi scrubber were very efficient in removing particulates and 99 Tc from the off-gas stream. Liquid scrubbers were not efficient in removing 131 I, as 25% of the total lost went to the building off-gas system. Therefore, solid adsorbents will be needed to remove iodine. For all future RLSWTF operations where iodine is present, a silver zeolite adsorber will be used

  3. Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

    International Nuclear Information System (INIS)

    Yoon, Seyoon; Moon, Juhyuk; Bae, Sungchul; Duan, Xiaonan; Giannelis, Emmanuel P.; Monteiro, Paulo M.

    2014-01-01

    This study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g −1 and 257 mg g −1 , respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol −1 or 121 mg g −1 ), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries. - Highlights: • We examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. • CLDH capacity to bind chloride ions in the hydrated cement paste is determined. • We model chloride adsorption by CLDH through the cement matrix. • CLDH reforms the layered structure with ion adsorption in the cement matrix

  4. Factors influencing the removal of fluoride from aqueous solution by calcined Mg-Al-CO{sub 3} layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Lv Liang [Key Laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Box 98, 15 Bei San Huan Dong Lu, Chao Yang District, Beijing 100029 (China); West Branch of Zhejiang University of Technology, Zhejiang 324006 (China); He Jing [Key Laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Box 98, 15 Bei San Huan Dong Lu, Chao Yang District, Beijing 100029 (China); Wei Min [Key Laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Box 98, 15 Bei San Huan Dong Lu, Chao Yang District, Beijing 100029 (China); Evans, D.G. [Key Laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Box 98, 15 Bei San Huan Dong Lu, Chao Yang District, Beijing 100029 (China); Duan Xue [Key Laboratory of Science and Technology of Controllable Chemical Reactions, Ministry of Education, Beijing University of Chemical Technology, Box 98, 15 Bei San Huan Dong Lu, Chao Yang District, Beijing 100029 (China)]. E-mail: duanx@mail.buct.edu.cn

    2006-05-20

    Layered double hydroxides (LDH) calcined at different temperatures (denoted as CLDH) have been demonstrated to recover their original layered structure in the presence of appropriate anions. In the light of this so-called 'memory effect', a study of removal of fluoride from aqueous solution by calcined Mg-Al-CO{sub 3}-LDH has been carried out. The LDH calcined at 500 deg. C had the highest capacity of removal of fluoride ion, because of retention of its intrinsic structure. The CLDH with an Mg/Al ratio of 2 has a remarkable ability to adsorb anions. The adsorption loading is higher for the calcined Mg-Al-LDH than for calcined Zn-Al and Ni-Al-LDH. The influence of varying the conditions for removal of fluoride, such as the pH of aqueous solution, the initial fluoride concentration, the dosage of adsorbent, and temperature on removal of fluoride have been investigated. The influence of co-existing anions in fluoride aqueous solution indicates that the percentage of removal of fluoride increased in order PO{sub 4} {sup 3-} < Cl{sup -} {approx} SO{sub 4} {sup 2-} < Br{sup -} << NO{sub 3} {sup -}. It was found that maximum removal of fluoride from aqueous solutions was obtained in 6 h at pH 6.0 with an initial concentration of 50 mg/L, and that the retention of fluoride ions by the CLDH material was 98% or higher. The residual fluoride concentration was found to be 0.4 mg/L with an initial concentration of 20 mg/L, which meets the national standard for drinking water quality. The Freundlich isotherm and Langmuir isotherm were used to fit the data of equilibrium experiments. The results of X-ray diffraction, FT-IR and TG-MS demonstrate that the adsorption phenomenon is accompanied by rehydration with concomitant uptake of fluoride ions to rebuild the initial layered structure.

  5. Synthesis of aluminum oxide by the polymer precursor method (Pechini) in 4: 1 ratio of citric acid: metal cation: calcination temperature effect

    International Nuclear Information System (INIS)

    Silva, M.C.; Lira, H.L.; Ribeiro, P.C.; Freitas, N.L.

    2014-01-01

    The technology field is nanopowders prominent in science since these materials fall in various sectors regarding their applications. This work aims at the synthesis of aluminum oxide by polymeric precursors in 4:1 ratio of citric acid:metal cation and evaluate the influence of calcination temperature on their structural and morphological characteristics. The samples after reaction were characterized by XRD and thermal analysis. After calcination 500-1200°C the samples were characterized by XRD, SEM and particle size distribution. The results showed that the variation of the calcination temperature is sufficient to achieve a same material with different structural and morphological characteristics. The most stable phase aluminum oxide arose only after calcination at 1100°C, below 900°C, the amorphous material appeared. As regards the morphology, the change was not as significant as compared to the structure. (author)

  6. Morphological Changes of Limestone Sorbent Particles during Carbonation/Calcination Looping Cycles in a Thermogravimetric Analyzer (TGA) and Reactivation with Steam

    KAUST Repository

    Wu, Y.; Blamey, J.; Anthony, E. J.; Fennell, P. S.

    2010-01-01

    Carbonation and calcination looping cycles were carried out on four limestones in a thermogravimetric analyzer (TGA). The CO2 carrying capacity of a limestone particle decays very quickly in the first 10 cycles, reducing to about 20% of its original

  7. Performance of Cobalt-Based Fischer-Tropsch Synthesis Catalysts Using Dielectric-Barrier Discharge Plasma as an Alternative to Thermal Calcination

    International Nuclear Information System (INIS)

    Bai Suli; Huang Chengdu; Lv Jing; Li Zhenhua

    2012-01-01

    Co-based catalysts were prepared by using dielectric-barrier discharge (DBD) plasma as an alternative method to conventional thermal calcination. The characterization results of N 2 -physisorption, temperature programmed reduction (TPR), transmission electron microscope (TEM), and X-ray diffraction (XRD) indicated that the catalysts prepared by DBD plasma had a higher specific surface area, lower reduction temperature, smaller particle size and higher cobalt dispersion as compared to calcined catalysts. The DBD plasma method can prevent the sintering and aggregation of active particles on the support due to the decreased treatment time (0.5 h) at lower temperature compared to the longer thermal calcination at higher temperature (at 500° C for 5 h). As a result, the catalytic performance of the Fischer-Tropsch synthesis on DBD plasma treated Co/SiO 2 catalyst showed an enhanced activity, C 5+ selectivity and catalytic stability as compared to the conventional thermal calcined Co/SiO 2 catalyst.

  8. Preparation and Characterization of Au/Pd Modified-TiO2 Photocatalysts for Phenol and Toluene Degradation under Visible Light—The Effect of Calcination Temperature

    Directory of Open Access Journals (Sweden)

    Anna Cybula

    2014-01-01

    Full Text Available Rutile loaded with Au/Pd nanoparticles was prepared using a water-in-oil microemulsion system of water/AOT/cyclohexane followed by calcination. The effect of calcination temperature (from 350 to 700°C on the structure of Au/Pd nanoparticles deposited at rutile matrix and the photocatalytic properties of Au/Pd-TiO2 was investigated in two model reactions (toluene degradation in gas phase and phenol degradation in aqueous phase. Toluene was irradiated over Au/Pd-TiO2 using light emitting diodes (LEDs, λmax⁡ = 415 nm. The sample 0.5 mol% Pd/TiO2 exhibited the highest activity under visible light irradiation in gas and aqueous phase reaction among all photocatalysts calcined at 350°C, while the sample modified only with gold nanoparticles showed the lowest activity. The Au/Pd-TiO2 sample calcinated at 350°C possesses the highest photocatalytic activity when degrading phenol under visible light, which is 14 times higher than that of the one calcinated at 450°C. It was observed that increasing temperature from 350 to 700°C during calcination step caused segregation of metals and finally resulted in photoactivity drop.

  9. Limestone calcination under calcium-looping conditions for CO2 capture and thermochemical energy storage in the presence of H2O: an in situ XRD analysis.

    Science.gov (United States)

    Valverde, Jose Manuel; Medina, Santiago

    2017-03-15

    This work reports an in situ XRD analysis of whether the calcination/carbonation behavior of natural limestone (CaCO 3 ) is affected by the addition of H 2 O to the calciner at a very low concentration under relevant Calcium-Looping (CaL) conditions for CO 2 capture in coal fired power plants (CFPP) and Thermochemical Energy Storage (TCES) in Concentrated Solar Power plants (CSP). Previous studies have demonstrated that the presence of steam in the calciner at a high concentration yields a significant increase in the reaction rate. However, a further undesired consequence is the serious deterioration of the CaO mechanical strength, which would lead to particle attrition and mass loss in any CaL process based on the use of circulating fluidized beds. The results presented in this manuscript on the time evolution of the wt% and crystallite size of the phases involved in the calcination/carbonation reactions indicate that the calcination rate is still notably increased by the presence of H 2 O at very low concentrations whereas the reactivity toward carbonation and crystal structure of the formed CaO are not essentially affected, which suggests that the CaO mechanical strength is not impaired. Thus, the benefit of using steam for calcination in the CaL process could be still retained while at the same time particle attrition would not be promoted.

  10. Radiant-heat spray-calcination process for the solid fixation of radioactive waste. Part 1, Non-radioactive pilot unit

    Energy Technology Data Exchange (ETDEWEB)

    Allemann, R.T.; Johnson, B.M. Jr.

    1960-11-14

    The fixation of radioactive waste in a stable solid media by means of calcination of these aqueous solutions has been the subject of considerable-effort throughout the U. S. Atomic Energy Commission and by atomic energy organizations in other countries. Several methods of doing this on a continuous or semi-continuous basis have been devised, and a fev have been demonstrated to be feasible for the handling of non-radioactive, or low-activity, simulated wastes. Notable among methods currently under development are: (a) batch-operated pot calcination of waste generated from reprocessing stainless steel clad fuel elements (Darex process) and Purex waste, (b) combination rotary kiln and ball mill calcination of aluminum nitrate (TBP-25 and Redox process), and (c) fluidized bed calcination of TBP-25 and Purex wastes. Although a considerable amount of engineering experience has been obtained on the calcination of dissolved salts in a fluidized bed, and the other methods have been the subjects of a great deal of study, none of them have been developed to-the extent which would rule out the desirability of further investigation of other possible methods of calcination.

  11. Obtaining a pozzolanic addition from the controlled calcination of paper mill sludge. Performance in cement matrices

    Directory of Open Access Journals (Sweden)

    San José, J. T.

    2006-09-01

    Full Text Available Mineralogically, the paper mill sludge consists essentially of calcite, kaolinite, talc and other philosilicates (illite, chlorite. When such sludge is subjected to controlled thermal treatment, its kaolinite component may be transformed into metakaolin, yielding a product with high pozzolanic reactivity. This study was designed to analyze a number of scientific questions around the production of pozzolanic additions via controlled thermal activation of paper mill sludge and to evaluate the performance of such additions when included in a cement matrix. The findings show that paper mill waste activation is optimal when the sludge is calcined for 2 hours at 700 ºC in the 700-800 ºC interval. A comparative study between the cement made with the new addition and a commercial cement (CEM I-42.5R used as a reference led to highlight the scientific and technical viability of this waste as a cementing secondary material.Los lodos de destintado del papel están constituidos,mineralógicamente, por calcita, caolinita, talco y otros filosilicatos (ilita, clorita. Cuando al lodo se le somete aun tratamiento térmico controlado, la caolinita puede transformarse en metacaolín, dando origen a un producto de alta reactividad puzolánica.El objeto de este trabajo es analizar diferentes aspectos científicos relativos al proceso de obtención de una adiciónpuzolánica a partir de la activación térmica controlada de lodos de destintado del papel, así como evaluar el comportamiento de la nueva adición cuando se incorpora en una matriz de cemento. Los resultados obtenidos ponen de manifiesto la recomendación de utilizar 700 ºC durante 2 horas de permanencia en el horno, como condiciones más óptimas para activar los residuos de lodos de papel en el intervalo 700-800 ºC. Del estudio comparativo del cemento elaborado con la nueva adición con respecto a un cemento comercial (CEM I-42,5R, se puede destacar la viabilidad científica y técnica de

  12. Adsorption of a cationic dye (Yellow Basic 28 ontothe calcined mussel shells: Kinetics, Isotherm and Thermodynamic Parameters

    Directory of Open Access Journals (Sweden)

    Imane EL Ouahabi

    2015-11-01

    Full Text Available The aim of this study is to valorise the mussel shells and evaluate the adsorption capacity of calcined mussel shells for the cationic dyes.  The adsorbent was characterized by DRX, FTIR, BET and SEM, respectively. The adsorption of Yellow Basic28 on calcined mussel shells was investigated using the parameters such as concentrations (10-50mg/L, pH (3-10, ionic strength (0-2 mol / L and temperature (288 - 318 °C.  The adsorption rate data were analysed according to the first and second-order kinetic models.  The adsorption kinetics was found to be best represented by the pseudo-second-order kinetic model.  The experimental isotherm data were analyzed using Langmuir, Freundlich, Temkin, Elovich and Dubinin–Radushkevich isotherm equations on the dye-adsorbent system. The experimental data yielded excellent fits with Freundlich isotherm equation (R² = 0.966. It was indicative of the heterogeneity of the adsorption sites on the CMS particles.  Various thermodynamic parameters such as enthalpy of adsorption ΔH°, free energy change ΔG°and entropy ΔS° were estimated.  The positive value of ΔH°(30.321 kJ/mol and negative values of ΔG° (from -5.392 to -2.873 kJ/mol show the process is endothermic and spontaneous.  The negative value of entropy ΔS° (-87.172 J/mol K suggest the decreased randomness at the solid-liquid interface during the adsorption of dyes onto calcined mussel shells.

  13. Influences of air calcination and steam activation on microstructure and photocatalytic activity of continuous TiO2 fibers

    International Nuclear Information System (INIS)

    You, Yang; Zhang, Shiying; Xu, Difa

    2013-01-01

    Graphical abstract: Display Omitted Highlights: ► Effects of air calcination and steam activation on TiO 2 fibers were studied. ► The photocatalytic activity was evaluated by degradation of formaldehyde. ► Steam activation promoted the anatase–rutile phase transformation. ► Steam activation decreased grain size and increased special surface area. ► Steam activation improved photocatalytic activity of TiO 2 fibers. -- Abstract: Effects of air calcination and steam activation, on phase transformation, microstructure and photocatalytic activity of continuous TiO 2 fibers prepared by sol–gel method were studied. The fibers were characterized by XRD, SEM, and N 2 adsorption–desorption. The photocatalytic activity was evaluated by photocatalytic degradation of formaldehyde. Results showed that 100% rutile fibers heat-treated in air and steam were obtained at 800 °C and 600 °C, respectively. The anatase grain sizes and special surface areas of the fibers heat-treated at 500 °C in air and steam were 31.6 nm, 22.7 nm, 26.7 m 2 /g and 32.3 m 2 /g, respectively. The degradation rates of formaldehyde over the fibers heat-treated at 500 °C in air and steam were 92.3% and 98.6% after 14 h under UV irradiation, respectively. Compared with the air calcination, the steam activation promoted the anatase–rutile phase transformation, reduced the grain size, increased the special surface area, and improved photocatalytic activity of continuous TiO 2 fibers.

  14. Performance assessment of CO2 capture with calcination carbonation reaction process driven by coal and concentrated solar power

    International Nuclear Information System (INIS)

    Zhang, Xuelei; Liu, Yingguang

    2014-01-01

    Calcination carbonation reaction (CCR) process is regarded as a promising option for pulverized coal power plant to mitigate CO 2 emission. In this paper, concentrated solar power (CSP) substitutes for coal to supply part of the calcination energy in order to reduce the fossil fuel consumption associated with the calciner. A CCR process driven by coal and CSP is examined from the perspective of energy efficiency. This paper focuses on the parameters of heat recovery efficiency, CSP capacity, compression energy, air separation energy and recycled energy to determine the contribution of each to the overall energy penalty. In addition, the effects of heat recovery efficiency, CSP capacity, purge percentage and CO 2 capture efficiency on the co-driven case are analyzed through a sensitivity analysis. The results indicate that the thermal efficiency of integrating CCR co-driven process into an ultra-supercritical 1019 MW power plant is 35.37%, which means that the overall efficiency penalty is 9.63 percentage points. Moreover, the co-driven case reduces the fossil fuel consumption and the mass flow rate of fresh sorbent and circulation solids compared with coal-driven case. Increasing heat recovery efficiency and CSP efficiency can improve the co-driven case performance. - Highlights: • We examine a CCR process driven by coal and concentrated solar power simultaneously. • The contributors to the overall energy penalty are quantitatively identified. • Obvious coal-saving effect has been found in the co-driven system. • A sensitivity analysis is conducted to find the impact of key parameters

  15. Technology status of spray calcination--vitrification of high-level liquid waste for full-scale application

    International Nuclear Information System (INIS)

    Keeley, R.B.; Bonner, W.F.; Larson, D.E.

    1977-01-01

    Spray calcination and vitrification technology for stabilization of high-level nuclear wastes has been developed to the point that initiation of technology transfer to an industrial-sized facility could begin. This report discusses current process and equipment development status together with additional R and D studies and engineering evaluations needed. Preliminary full-scale process and equipment descriptions are presented. Technology application in a full-scale plant would blend three distinct maintenance design philosophies, depending on service life anticipated: (1) totally remote maintenance with limited viewing and handling equipment, (2) totally remote maintenance with extensive viewing and handling equipment, and (3) contact maintenance

  16. The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on adsorption of Cr (VI) from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Lili [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China); Ma Wei, E-mail: chmawv@yahoo.com [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China); Han Mei; Cheng Zihong [College of Chemistry, Dalian University of Technology, Dalian, Liaoning 116023 (China)

    2011-02-15

    Research highlights: {yields} The reconstruction processes of CH-Mg/Al and CH-Mg/Al/Fe were fast and efficient, but the adsorption of Cr (VI) on CH-Mg/Al/Fe reached equilibrium faster. {yields} The removal mechanism involved not only intercalation but also adsorption on external surface of the layers and interlayer anion exchange. {yields} The existence of Fe3{sup +} in Mg/Al calcined hydrotalcite led to the interlayer anion exchange more difficult and it is affected equilibrium amount of Cr (VI) adsorption. - Abstract: The influence of ferric iron in calcined nano-Mg/Al hydrotalcite on removal of Cr (VI) from aqueous solution was studied from aspects of structure characteristics, adsorption properties and mechanism discussions. The calcined hydrotalcites (CH-Mg/Al and CH-Mg/Al/Fe) were obtained by thermal decomposition of their corresponding precursors and characterized by XRD, TEM, pH{sub PZC} and FTIR. The adsorption properties were studied as a function of pH, initial Cr (VI) concentration and contact time. The results showed that the nature of adsorption is endothermic and spontaneous for both CH-Mg/Al and CH-Mg/Al/Fe, but the thermodynamic parameter value changes revealed the addition of Fe{sup 3+} is disadvantage to adsorption process and the theoretical saturated adsorption capacity decreased by approximately 10.2 mg/g at tested temperatures. The removal mechanism involved not only intercalation but adsorption on external surface of the layers and interlayer anion exchange for both CH-Mg/Al and CH-Mg/Al/Fe. Furthermore, the results also indicated that intercalation accounts for a large proportion during removal process whatever for CH-Mg/Al, or for CH-Mg/Al/Fe. Additionally, the replacement of Al{sup 3+} by Fe{sup 3+} in CH-Mg/Al led to the interlayer anion exchange more difficult. On the basis of the results, it is concluded that the existence of ferric iron in calcined Mg/Al hydrotalcite is unfavorable to removal of Cr (VI) from aqueous solution.

  17. Arsenic removal from aqueous solutions using Fe3O4-HBC composite: effect of calcination on adsorbents performance.

    Directory of Open Access Journals (Sweden)

    Shams Ali Baig

    Full Text Available The presence of elevated concentration of arsenic in water sources is considered to be health hazard globally. Calcination process is known to change the surface efficacy of the adsorbent. In current study, five adsorbent composites: uncalcined and calcined Fe3O4-HBC prepared at different temperatures (400°C and 1000°C and environment (air and nitrogen were investigated for the adsorptive removal of As(V and As(III from aqueous solutions determining the influence of solution's pH, contact time, temperature, arsenic concentration and phosphate anions. Characterizations from FTIR, XRD, HT-XRD, BET and SEM analyses revealed that the Fe3O4-HBC composite at higher calcination temperature under nitrogen formed a new product (fayalite, Fe2SiO4 via phase transformation. In aqueous medium, ligand exchange between arsenic and the effective sorbent site ( = FeOOH was established from the release of hydroxyl group. Langmuir model suggested data of the five adsorbent composites follow the order: Fe3O4-HBC-1000°C(N2>Fe3O4-HBC (uncalcined>Fe3O4-HBC-400°C(N2>Fe3O4-HBC-400°C(air>Fe3O4-HBC-1000°C(air and the maximum As(V and As(III adsorption capacities were found to be about 3.35 mg g(-1 and 3.07 mg g(-1, respectively. The adsorption of As(V and As(III remained stable in a wider pH range (4-10 using Fe3O4-HBC-1000°C(N2. Additionally, adsorption data fitted well in pseudo-second-order (R2>0.99 rather than pseudo-first-order kinetics model. The adsorption of As(V and As(III onto adsorbent composites increase with increase in temperatures indicating that it is an endothermic process. Phosphate concentration (0.0l mM or higher strongly inhibited As(V and As(III removal through the mechanism of competitive adsorption. This study suggests that the selective calcination process could be useful to improve the adsorbent efficiency for enhanced arsenic removal from contaminated water.

  18. Arsenic removal from aqueous solutions using Fe3O4-HBC composite: effect of calcination on adsorbents performance.

    Science.gov (United States)

    Baig, Shams Ali; Sheng, TianTian; Sun, Chen; Xue, XiaoQin; Tan, LiSha; Xu, XinHua

    2014-01-01

    The presence of elevated concentration of arsenic in water sources is considered to be health hazard globally. Calcination process is known to change the surface efficacy of the adsorbent. In current study, five adsorbent composites: uncalcined and calcined Fe3O4-HBC prepared at different temperatures (400°C and 1000°C) and environment (air and nitrogen) were investigated for the adsorptive removal of As(V) and As(III) from aqueous solutions determining the influence of solution's pH, contact time, temperature, arsenic concentration and phosphate anions. Characterizations from FTIR, XRD, HT-XRD, BET and SEM analyses revealed that the Fe3O4-HBC composite at higher calcination temperature under nitrogen formed a new product (fayalite, Fe2SiO4) via phase transformation. In aqueous medium, ligand exchange between arsenic and the effective sorbent site ( = FeOOH) was established from the release of hydroxyl group. Langmuir model suggested data of the five adsorbent composites follow the order: Fe3O4-HBC-1000°C(N2)>Fe3O4-HBC (uncalcined)>Fe3O4-HBC-400°C(N2)>Fe3O4-HBC-400°C(air)>Fe3O4-HBC-1000°C(air) and the maximum As(V) and As(III) adsorption capacities were found to be about 3.35 mg g(-1) and 3.07 mg g(-1), respectively. The adsorption of As(V) and As(III) remained stable in a wider pH range (4-10) using Fe3O4-HBC-1000°C(N2). Additionally, adsorption data fitted well in pseudo-second-order (R2>0.99) rather than pseudo-first-order kinetics model. The adsorption of As(V) and As(III) onto adsorbent composites increase with increase in temperatures indicating that it is an endothermic process. Phosphate concentration (0.0l mM or higher) strongly inhibited As(V) and As(III) removal through the mechanism of competitive adsorption. This study suggests that the selective calcination process could be useful to improve the adsorbent efficiency for enhanced arsenic removal from contaminated water.

  19. Physical, Chemical and Structural Evolution of Zeolite-Containing Waste Forms Produced from Metakaolinite and Calcined HLW

    International Nuclear Information System (INIS)

    Grutzeck, Michael; Jantzen, Carol M.

    1999-01-01

    Natural and synthetic zeolites are extremely versatile materials. They can adsorb a variety of liquids and gases, and also take part in cation exchange reactions. Zeolites are easy to synthesize from a wide variety of natural and man made materials. One combination of starting materials that exhibits a great deal of promise is a mixture of metakaolinite and/or Class F fly ash and concentrated sodium hydroxide solution. Once these ingredients are mixed and cured at elevated temperatures, they react to form a hard, dense, ceramic-like material that contains significant amounts of crystalline tectosilicates (zeolites and feldspathoids). Zeolites have the ability to sequester ions in lattice positions or within their networks of channels and voids. As such they are nearly perfect waste forms, the zeolites can host alkali, alkaline earth and a variety of higher valance cations. In addition to zeolites, it has been found that the zeolites are accompanied by an alkali aluminosilicate hydrate matrix that is a host, not only to the zeolites, but to residual amounts of insoluble hydroxide phases as well. A previous publication has established the fact that a mixture of a calcined equivalent ICPP waste (sodium aluminate/hydroxide solution containing ∼3:1 Na:Al) and fly ash and/or metakaolinite could be cured at various temperatures to produce a monolith containing Zeolite A (80 C) or Na-P1 plus hydroxy sodalite (130 C) crystals dispersed in an alkali aluminosilicate hydrate matrix. Dissolution tests have shown these materials (so-called hydroceramics) to have superior retention for alkali, alkaline earth and heavy metal ions. The zeolitization process is a simple one. Metakaolinite and/or Class F fly ash is mixed with a caustic sodium-bearing calcine and enough water to make a thick paste. The paste is transferred to a metal canister and ''soaked'' for a few hours at 70-80 C prior to steam autoclaving the sample at ∼200 C for 6-8 hours. The waste form produced in this

  20. Determination of the Index of Consumption of Petroleum of the Calcining Kiln of the Ernesto Che Guevara Commander Undertaking

    Directory of Open Access Journals (Sweden)

    Yarilys Gaínza-Delgado

    2016-07-01

    Full Text Available This work presents the results obtained in carrying out the mass and energy balances in the calcining kiln of the company commander Ernesto Che Guevara, for determining the consumption index of petroleum used for obtaining nickel oxide through thermal decomposition of the basic nickel carbonate. It was shown that for a production of basic nickel carbonate of              12 t / h with 69% moisture, it is necessary to feed about 1100 kg / h of fuel, for an consumption index of 91.67 kg of fuel per ton of load.

  1. Synthesis of anatase nanopowders by sol-gel method and influence of temperatures of calcination to their photocatalitic properties

    Directory of Open Access Journals (Sweden)

    Golubović A.

    2015-01-01

    Full Text Available The titanium dioxide (TiO2 nanopowders were produced by sol-gel technique from tetrabutyl titanate as a precursor, varying the temperature оf calcination (from 500 to 550°C with the step of 10 °C. XRPD results have shown that all synthesized nanopowders are dominantly in anatase phase. The analysis of the shift and linewidth of the most intensive anatase Eg Raman mode confirmed the XRPD results and added the presence of small amount of highly disordered brookite phase in all samples. The analysis of pore structure from nitrogen sorption experimental data described all samples as mesoporous, with mean pore diameters in the range of 1.5 and 4.5 nm. Nanopowder properties have been related to the photocatalytic activity, tested in degradation of the textile dye (C.I. Reactive Orange 16. The sample calcined at temperature of 510°C showed the best photocatalytic performance. [Projekat Ministarstva nauke Republike Srbije, br. III45018 i br. OI171032

  2. Effects of Calcination Holding Time on Properties of Wide Band Gap Willemite Semiconductor Nanoparticles by the Polymer Thermal Treatment Method

    Directory of Open Access Journals (Sweden)

    Ibrahim Mustapha Alibe

    2018-04-01

    Full Text Available Willemite is a wide band gap semiconductor used in modern day technology for optoelectronics application. In this study, a new simple technique with less energy consumption is proposed. Willemite nanoparticles (NPs were produced via a water–based solution consisting of a metallic precursor, polyvinylpyrrolidone (PVP, and underwent a calcination process at 900 °C for several holding times between 1–4 h. The FT–IR and Raman spectra indicated the presence of metal oxide bands as well as the effective removal of PVP. The degree of the crystallization and formation of the NPs were determined by XRD. The mean crystallite size of the NPs was between 18.23–27.40 nm. The morphology, particle shape and size distribution were viewed with HR-TEM and FESEM analysis. The willemite NPs aggregate from the smaller to larger particles with an increase in calcination holding time from 1–4 h with the sizes ranging between 19.74–29.71 nm. The energy values obtained from the experimental band gap decreased with increasing the holding time over the range of 5.39 eV at 1 h to at 5.27 at 4 h. These values match well with band gap obtained from the Mott and Davis model for direct transition. The findings in this study are very promising and can justify the use of these novel materials as a potential candidate for green luminescent optoelectronic applications.

  3. Production of U3O8 by uranyl formate precipitation and calcination in a full-scale pilot facility

    International Nuclear Information System (INIS)

    Kendrick, L.S.; Wilson, W.A.; Mosley, W.C.

    1984-08-01

    The uranyl formate process for the production of U 3 O 8 with a controlled particle size has been extensively studied on a laboratory scale. Based on this study, a pilot-scale facility (the Uranyl Formate Facility) was built to investigate the key steps of the process on a larger scale. These steps were the precipitation of a uranyl formate monohydrate salt and the calcination of this salt to U 3 O 8 . Tests of the facility and process were conducted at conditions recommended by the laboratory-scale studies for a full-scale production facility. These tests demonstrated that U 3 O 8 of the required particle size for the PM process can be produced on a plant scale by the calcination of uranyl formate crystals. The performance of the U 3 O 8 produced by the uranyl formate process in fuel tube fabrication was also investigated. Small-scale extrusion tests of U 3 O 8 -Al cores which used the U 3 O 8 produced in the Uranyl Formate Facility were conducted. These tests demonstrated that the U 3 O 8 quality was satisfactory for the PM process

  4. Reactivation properties of carbide slag as a CO{sub 2} sorbent during calcination/carbonation cycles

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yingjie; Sun, Rongyue; Liu, Hongling; Lu, Chunmei [Shandong Univ., Jinan (China). School of Energy and Power Engineering

    2013-07-01

    The carbide slag from polyvinyl chloride production as industry hazardous wastes was proposed as CO{sub 2} sorbent at high temperature in calcium looping cycle. The cyclic CO{sub 2} capture behavior and the microstructure characteristics of the carbide slag as one of the typical calcium-based industrial wastes during the multiple calcination/carbonation cycles. Also, the comparisons between the carbide slag and the natural limestone in cyclic CO{sub 2} capture behavior were made. XRD analysis demonstrates that the predominating constituent of the carbide slag is Ca(OH){sub 2}. The carbonation temperature ranging from 650 to 700 C is favourable to cyclic carbonation of the carbide slag. The cyclic carbonation conversions of the carbide slag is lower than that of the limestone before a certain time, but the situation is converse after that time in a thermogravimetric analyzer. The carbide slag has better cyclic CO{sub 2} capture capacity. The carbonation conversion of the carbide slag retains 0.28 after 100 calcination/carbonation cycles, while the two limestones achieve 0.08 and 0.14 respectively at the same reaction conditions in a dual fixed-bed reactor. The microstructure of the carbide slag by SEM reveals the reason why it possesses better CO{sub 2} capture capacity.

  5. Carbothermic reduction of electric arc furnace dust and calcination of waelz oxide by semi-pilot scale rotary furnace

    Directory of Open Access Journals (Sweden)

    Morcali M.H.

    2012-01-01

    Full Text Available The paper gives a common outline about the known recycling techniques from electric arc furnace dusts and describes an investigation of a pyrometallurgical process for the recovery of zinc and iron from electric arc furnace dusts (EAFD. In the waelz process, the reduction of zinc and iron from the waste oxides using solid carbon (lignite coal was studied. In the reduction experiments; temperature, time and charge type (powder and pellet were investigated in detail. It was demonstrated that zinc and iron recovery (% increases with increasing temperature as well as time. Pelletizing was found to be a better method than using the powder as received for the zinc recovery and iron conversion (. In the calcination (roasting process, crude zinc oxide, which evaporated from non-ferric metals were collected as condensed product (crude waelz oxide, was heated in air atmosphere. Lead, cadmium as well as chlorine and other impurities were successfully removed from crude waelz oxide by this method. In the calcination experiments; temperature and time are investigated in detail. It was demonstrated that zinc purification (% increases with increasing temperature. The highest zinc refining (% was obtained at 1200°C for 120 minutes. A kinetic study was also undertaken to determine the activation energy of the process. Activation energies were 242.77 kJ/mol for the zinc recovery with powder forms, 261.99 kJ/mol for the zinc recovery with pellet forms respectively. It was found that, initially, the reaction was chemically controlled.

  6. A comparative study of thermal calcination and an alkaline hydrolysis method in the isolation of hydroxyapatite from Thunnus obesus bone

    International Nuclear Information System (INIS)

    Venkatesan, Jayachandran; Ryu, BoMi; Thomas, Noel Vinay; Kim, Se Kwon; Qian Zhongji

    2011-01-01

    In the present study, hydroxyapatite (HAp) was isolated from Thunnus obesus bone using alkaline hydrolysis and thermal calcination methods. The obtained ceramic has been characterized by thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), powder x-ray diffraction analysis (XRD), field-emission scanning electron microscopy, energy-dispersive x-ray analysis, transmission electron microscopy (TEM), selected area diffraction analysis, cytotoxic analysis and cell proliferation analysis. The results indicate that there are significant differences between the ceramics and T. obesus bone. FT-IR and TGA results affirmed that the collagen and organic moieties have been eliminated by both the proposed methods. XRD results were in agreement with JCPDS data. TEM and selective area diffraction images have signified that the thermal calcination method produces good crystallinity with dimensions 0.3-1.0 μm, whereas the alkaline hydrolysis method produces nanostructured HAp crystals with 17-71 nm length and 5-10 nm width. Biocompatibility of HAp crystals was evaluated by cytotoxicity and cell proliferation with human osteoblast-like cell MG-63.

  7. A comparative study of thermal calcination and an alkaline hydrolysis method in the isolation of hydroxyapatite from Thunnus obesus bone

    Energy Technology Data Exchange (ETDEWEB)

    Venkatesan, Jayachandran; Ryu, BoMi; Thomas, Noel Vinay; Kim, Se Kwon [Department of Chemistry, Pukyong National University, Busan 608-737 (Korea, Republic of); Qian Zhongji, E-mail: sknkim@pknu.ac.kr [Marine Bioprocess Research Center, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2011-06-15

    In the present study, hydroxyapatite (HAp) was isolated from Thunnus obesus bone using alkaline hydrolysis and thermal calcination methods. The obtained ceramic has been characterized by thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), powder x-ray diffraction analysis (XRD), field-emission scanning electron microscopy, energy-dispersive x-ray analysis, transmission electron microscopy (TEM), selected area diffraction analysis, cytotoxic analysis and cell proliferation analysis. The results indicate that there are significant differences between the ceramics and T. obesus bone. FT-IR and TGA results affirmed that the collagen and organic moieties have been eliminated by both the proposed methods. XRD results were in agreement with JCPDS data. TEM and selective area diffraction images have signified that the thermal calcination method produces good crystallinity with dimensions 0.3-1.0 {mu}m, whereas the alkaline hydrolysis method produces nanostructured HAp crystals with 17-71 nm length and 5-10 nm width. Biocompatibility of HAp crystals was evaluated by cytotoxicity and cell proliferation with human osteoblast-like cell MG-63.

  8. Effects of La-Zn substituent and calcination temperature on the microstructure and magnetic properties of Sr-ferrites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiangcheng; Zhao, Zhang; Zhu, Boquan [Wuhan Univ. of Science and Technology (China). State Key Lab. of Refractories and Metallurgy

    2015-01-15

    In this study, La-Zn-substituted SrFe{sub 12}O{sub 19} ferrites were synthesized using the traditional ceramic process. The by-products of iron oxide scales from a steel plant were used as the main raw materials. The influence of the La-Zn substituent and the calcination temperature on the microstructure and magnetic properties of Sr{sub 1-x}La{sub x}Fe{sub 12-x}Zn{sub x}O{sub 19} ferrites was investigated. The results showed that with the increase in the x value, the crystalline lattice constant of the a- and c-axes and the cell volume decreased. There was no α-Fe{sub 2}O{sub 3} phase in the ferrites when the value of x was 0.3. The corresponding saturation magnetization (M{sub s}) and remnant magnetization (M{sub r}) values were, respectively, about 65 emu g{sup -1} and 39.5 emu g{sup -1}. Both values of M{sub s} and M{sub r} rise to the maximum value. When the calcination temperature was reduced from 1200 C to 1150 C, the average particle size decreased from 0.9 μm to 0.7 μm and M{sub s} remained at 65 emu g{sup -1}. However, the coercivity increased from 2690 Oe to 3100 Oe.

  9. Relevance of the Physicochemical Properties of Calcined Quail Eggshell (CaO as a Catalyst for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Leandro Marques Correia

    2017-01-01

    Full Text Available The CaO solid derived from natural quail eggshell was calcined and employed as catalyst to produce biodiesel via transesterification of sunflower oil. The natural quail eggshell was calcined at 900°C for 3 h, in order to modify the calcium carbonate present in its structure in CaO, the activity phase of the catalyst. Both precursor and catalyst were characterized using Hammett indicators method, X-ray fluorescence (XRF, X-ray diffraction (XRD, thermogravimetric analysis (TG/DTG, CO2 temperature-programmed desorption (CO2-TPD, X-ray photoelectronic spectroscopy (XPS, Fourier infrared spectroscopy (FTIR, scanning electron microscopy (SEM, N2 adsorption-desorption at −196°C, and distribution particle size. The maximum biodiesel production was of 99.00 ± 0.02 wt.% obtained in the following transesterification reaction conditions: XMR (sunflower oil/methanol molar ratio of 1 : 10.5 mol : mol, XCAT (catalyst loading of 2 wt.%, XTIME (reaction time of 2 h, stirring rate of 1000 rpm, and temperature of 60°C.

  10. Oxidative desulfurization of benzothiophene and thiophene with WOx/ZrO2 catalysts: effect of calcination temperature of catalysts.

    Science.gov (United States)

    Hasan, Zubair; Jeon, Jaewoo; Jhung, Sung Hwa

    2012-02-29

    Oxidative desulfurization (ODS) of model fuel containing benzothiophene (BT) or thiophene (Th) has been carried out with WO(x)/ZrO2 catalyst, which was calcined at various temperatures. Based on the conversion of BT in the model fuel, it can be shown that the optimum calcination temperature of WOx/ZrO2 catalyst is around 700 °C. The most active catalyst is composed of tetragonal zirconia (ZrO2) with well dispersed polyoxotungstate species and it is necessary to minimize the contents of the crystalline WO3 and monoclinic ZrO2 for a high BT conversion. The oxidation rate was interpreted with the first-order kinetics, and it demonstrated the importance of electron density since the kinetic constant for BT was higher than that for Th even though the BT is larger than Th in size. A WOx/ZrO2 catalyst, treated suitably, can be used as a reusable active catalyst in the ODS. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Electro-oxidation nitrite based on copper calcined layered double hydroxide and gold nanoparticles modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Cui Lin; Meng Xiaomeng; Xu Minrong; Shang Kun [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Ai Shiyun, E-mail: ashy@sdau.edu.cn [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China); Liu Yinping [College of Chemistry and Material Science, Shandong Agricultural University, Taian 271018, Shandong (China)

    2011-11-30

    Highlights: > A nitrite sensor fabricated based on copper calcined layered double hydroxides and gold nanoparticles modified electrode. > This sensor exhibited excellent electrocatalytic oxidation to nitrite. > This nitrite sensor exhibited very good analytical performance with low cost, convenient preparation and rapid detection. - Abstract: In this paper, a novel nitrite sensor was constructed based on electrodeposition of gold nanoparticles (AuNPs) on a copper calcined layered double hydroxide (Cu-CLDH) modified glassy carbon electrode. Electrochemical experiments showed that AuNPs/CLDH composite film exhibited excellent electrocatalytic oxidation activity with nitrite due to the synergistic effect of the Cu-CLDH with AuNPs. The fabricated sensor exhibited excellent performance for nitrite detection within a wide concentration interval of 1-191 {mu}M and with a detection limit of 0.5 {mu}M. The superior electrocatalytic response to nitrite was mainly attributed to the large surface area, minimized diffusion resistance, and enhanced electron transfer of the Cu-CLDH and AuNPs composition film. This platform offers a novel route for nitrite sensing with wide analytical applications and will supply the practical applications for a variety of simple, robust, and easy-to-manufacture analytical approaches in the future.

  12. Electro-oxidation nitrite based on copper calcined layered double hydroxide and gold nanoparticles modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Cui Lin; Meng Xiaomeng; Xu Minrong; Shang Kun; Ai Shiyun; Liu Yinping

    2011-01-01

    Highlights: → A nitrite sensor fabricated based on copper calcined layered double hydroxides and gold nanoparticles modified electrode. → This sensor exhibited excellent electrocatalytic oxidation to nitrite. → This nitrite sensor exhibited very good analytical performance with low cost, convenient preparation and rapid detection. - Abstract: In this paper, a novel nitrite sensor was constructed based on electrodeposition of gold nanoparticles (AuNPs) on a copper calcined layered double hydroxide (Cu-CLDH) modified glassy carbon electrode. Electrochemical experiments showed that AuNPs/CLDH composite film exhibited excellent electrocatalytic oxidation activity with nitrite due to the synergistic effect of the Cu-CLDH with AuNPs. The fabricated sensor exhibited excellent performance for nitrite detection within a wide concentration interval of 1-191 μM and with a detection limit of 0.5 μM. The superior electrocatalytic response to nitrite was mainly attributed to the large surface area, minimized diffusion resistance, and enhanced electron transfer of the Cu-CLDH and AuNPs composition film. This platform offers a novel route for nitrite sensing with wide analytical applications and will supply the practical applications for a variety of simple, robust, and easy-to-manufacture analytical approaches in the future.

  13. Influence of calcination temperature on the structure and morphology of HAp bioceramics; Influencia da temperatura de calcinacao na estrutura e morfologia de bioceramica de HAp

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, C.M.L.; Santos, P.T.A.; Rodrigues, P.A.; Costa, A.C.F.M. [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2012-07-01

    This study aimed to evaluate the influence of calcination temperature on the structure and morphology of samples of hydroxyapatite (HAp) synthesized by the wet method. For hydroxyapatite was used as precursor solutions of calcium hydroxide and phosphoric acid 1M solution of calcium hydroxide was stirred and heated to 80 ° C and then dropwise with a solution of phosphoric acid. After the liquid was evaporated without an oven at 110 ° C and sieved. The sample of PA as synthesized was submitted to calcination at 900 °C and 1100 °C / 2 hours. The samples as synthesized and after calcination were characterized by XRD, XRF, FTIR, SEM. The XRD showed the presence of phase hydroxyapatite for samples without calcining and both calcination temperatures studied. FTIR spectra showed bands group and PO{sub 4}{sup 3-}, CO{sub 3}{sup 2-}. Through the SEM micrograph, there is the formation of agglomerates in the form of porous flakes approximately spherical shape. (author)

  14. New DC conductivity spectra of Zn–Al layered double hydroxide (Zn–Al–NO3–LDH and its calcined product of ZnO phase

    Directory of Open Access Journals (Sweden)

    Abdullah Ahmed Ali Ahmed

    2017-05-01

    Full Text Available Zn–Al–NO3–LDH nanostructure was synthesized via the coprecipitation method at molar ratio Zn2+/Al3+ = 4 and pH = 7. The resultant sample was thermally treated at calcined temperatures of 50, 100, 150, 200, 250 and 300 °C. The layered structure of the Zn–Al–NO3–LDH samples was stable below the calcination temperature 200 °C as shown in powder X-ray diffraction (PXRD patterns of calcined samples. The calcination products showed a collapse of LDH structure and ZnO phase was formed at 200 °C and above. The dielectric spectroscopy of LDH was explained using anomalous low frequency dispersion (ALFD due to the low mobility of LDH carriers. The conductivity spectra of LDH can be theoretically described according to the effective phase within the calcination products of LDH. In the comparison with previously researches, this study presented higher values of DC conductivity for all studied samples.

  15. Evaluation of blends bauxite-calcination-method red mud with other industrial wastes as a cementitious material: Properties and hydration characteristics

    International Nuclear Information System (INIS)

    Zhang Na; Liu Xiaoming; Sun Henghu; Li Longtu

    2011-01-01

    Red mud is generated from alumina production, and its disposal is currently a worldwide problem. In China, large quantities of red mud derived from bauxite calcination method are being discharged annually, and its utilization has been an urgent topic. This experimental research was to evaluate the feasibility of blends red mud derived from bauxite calcination method with other industrial wastes for use as a cementitious material. The developed cementitious material containing 30% of the bauxite-calcination-method red mud possessed compressive strength properties at a level similar to normal Portland cement, in the range of 45.3-49.5 MPa. Best compressive strength values were demonstrated by the specimen RSFC2 containing 30% bauxite-calcination-method red mud, 21% blast-furnace slag, 10% fly ash, 30% clinker, 8% gypsum and 1% compound agent. The mechanical and physical properties confirm the usefulness of RSFC2. The hydration characteristics of RSFC2 were characterized by XRD, FTIR, 27 Al MAS-NMR and SEM. As predominant hydration products, ettringite and amorphous C-S-H gel are principally responsible for the strength development of RSFC2. Comparing with the traditional production for ordinary Portland cement, this green technology is easier to be implemented and energy saving. This paper provides a key solution to effectively utilize bauxite-calcination-method red mud.

  16. Hydrogen Production by Steam Reforming of Ethanol over Nickel Catalysts Supported on Sol Gel Made Alumina: Influence of Calcination Temperature on Supports.

    Science.gov (United States)

    Yaakob, Zahira; Bshish, Ahmed; Ebshish, Ali; Tasirin, Siti Masrinda; Alhasan, Fatah H

    2013-05-30

    Selecting a proper support in the catalyst system plays an important role in hydrogen production via ethanol steam reforming. In this study, sol gel made alumina supports prepared for nickel (Ni) catalysts were calcined at different temperatures. A series of (Ni/Al S.G. ) catalysts were synthesized by an impregnation procedure. The influence of varying the calcination temperature of the sol gel made supports on catalyst activity was tested in ethanol reforming reaction. The characteristics of the sol gel alumina supports and Ni catalysts were affected by the calcination temperature of the supports. The structure of the sol gel made alumina supports was transformed in the order of γ → (γ + θ) → θ-alumina as the calcination temperature of the supports increased from 600 °C to 1000 °C. Both hydrogen yield and ethanol conversion presented a volcano-shaped behavior with maximum values of 4.3 mol/mol ethanol fed and 99.5%, respectively. The optimum values were exhibited over Ni/Al S.G800 (Ni catalyst supported on sol gel made alumina calcined at 800 °C). The high performance of the Ni/Al S.G800 catalyst may be attributed to the strong interaction of Ni species and sol gel made alumina which lead to high nickel dispersion and small particle size.

  17. Effect of aluminum and silicon reactants and process parameters on glass-ceramic waste form characteristics for immobilization of high-level fluorinel-sodium calcined waste

    International Nuclear Information System (INIS)

    Vinjamuri, K.

    1993-06-01

    In this report, the effects of aluminum and silicon reactants, process soak time and the initial calcine particle size on glass-ceramic waste form characteristics for immobilization of the high-level fluorinel-sodium calcined waste stored at the Idaho Chemical Processing Plant (ICPP) are investigated. The waste form characteristics include density, total and normalized elemental leach rates, and microstructure. Glass-ceramic waste forms were prepared by hot isostatically pressing (HIPing) a pre-compacted mixture of pilot plant fluorinel-sodium calcine, Al, and Si metal powders at 1050 degrees C, 20,000 psi for 4 hours. One of the formulations with 2 wt % Al was HIPed for 4, 8, 16 and 24 hours at the same temperature and pressure. The calcine particle size range include as calcined particle size smaller than 600 μm (finer than -30 mesh, or 215 μm Mass Median Diameter, MMD) and 180 μm (finer than 80 mesh, or 49 μm MMD)

  18. Spring 2009 Semiannual (III.H. and I.U.) Report for the HWMA/RCRA Post-Closure Permit for the INTEC Waste Calcining Facility at the INL Site

    International Nuclear Information System (INIS)

    Boehmer, Ann M.

    2009-01-01

    The Waste Calcining Facility is located at the Idaho Nuclear Technology and Engineering Center. In 1999, the Waste Calcining Facility was closed under and approved Hazardous Waste Management Act/Resource Conservation and Recovery Act Closure plan. Vessels and spaces were grouted and then covered with a concrete cap. This permit sets forth procedural requirements for groundwater characterization and monitoring, maintenance, and inspections of the Waste Calcining Facility to ensure continued protection of human health and the environment.

  19. Spring 2009 Semiannual (III.H. and I.U.) Report for the HWMA/RCRA Post-Closure Permit for the INTEC Waste Calcining Facility at the INL Site

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, Ann M.

    2009-05-31

    The Waste Calcining Facility is located at the Idaho Nuclear Technology and Engineering Center. In 1999, the Waste Calcining Facility was closed under and approved Hazardous Waste Management Act/Resource Conservation and Recovery Act Closure plan. Vessels and spaces were grouted and then covered with a concrete cap. This permit sets forth procedural requirements for groundwater characterization and monitoring, maintenance, and inspections of the Waste Calcining Facility to ensure continued protection of human health and the environment.

  20. Hot isostatically-pressed aluminosilicate glass-ceramic with natural crystalline analogues for immobilizing the calcined high-level nuclear waste at the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Raman, S.

    1993-12-01

    The additives Si, Al, MgO, P 2 O 5 were mechanically blended with fluorinelsodium calcine in varying proportions. The batches were vacuum sealed in stainless steel canisters and hot isostatically pressed at 20,000 PSI and 1000 C for 4 hours. The resulting suite of glass-ceramic waste forms parallels the natural rocks in microstructural and compositional heterogeneity. Several crystalline phases ar analogous in composition and structure to naturally occurring minerals. Additional crystalline phases are zirconia and Ca-Mg borate. The glasses are enriched in silica and alumina. Approximately 7% calcine elements occur dissolved in this glass and the total glass content in the waste forms averages 20 wt%. The remainder of the calcine elements are partitioned into crystalline phases at 75 wt% calcine waste loading. The waste forms were tested for chemical durability in accordance with the MCC1-test procedure. The leach rates are a function of the relative proportions of additives and calcine, which in turn influence the composition and abundances of the glass and crystalline phases. The DOE leach rate criterion of less than 1 g/m 2 -day is met by all the elements B, Cs and Na are increased by lowering the melt viscosity. This is related to increased crystallization or devitrification with increases in MgO addition. This exploratory work has shown that the increases in waste loading occur by preferred partitioning of the calcine components among crystalline and glass phases. The determination of optimum processing parameters in the form of additive concentration levels, homogeneous blending among the components, and pressure-temperature stabilities of phases must be continued to eliminate undesirable effects of chemical composition, microstructure and glass devitrification

  1. 2.4. The kinetics of hydrochloric-acid decomposition of calcined concentrate of boron raw material of Ak-Arkhar Deposit

    International Nuclear Information System (INIS)

    Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

    2015-01-01

    Present article is devoted to kinetics of hydrochloric-acid decomposition of calcined concentrate of boron raw material of Ak-Arkhar Deposit. The experimental data of dependence of hydrochloric-acid decomposition of calcined boron raw material for boron oxide extraction on temperature (20-80 deg C) and process duration (15-60 min) were considered. It was defined that at temperature increasing the boron oxide extraction from borosilicate raw material increases from 24.1 till 86.8%. The constants of decomposition rate of boron raw material were calculated.

  2. The effect of calcination temperature on the performance of Co3O4-Bi2O3 as a heterogeneous catalyst of peroxymonosulfate

    Science.gov (United States)

    Zhang, Guangshan; Hu, Limin; Wang, Peng; Yuan, Yixing

    2017-11-01

    In this work, a time-saving microwave-assisted method for synthesis of Co3O4-Bi2O3 was reported. The synthesized Co3O4-Bi2O3 samples were characterized with different techniques to probe their crystalline structures and morphologies. The catalytic performances of synthesized Co3O4-Bi2O3 as peroxymonosulfate activator were evaluated by the degradation of bisphenol A. The effect of calcination temperature on Co3O4-Bi2O3 products was explored and the result showed that the sample calcined at 400 °C possessing superior catalytic activity.

  3. Self-assembled 3D flower-like Ni2+-Fe3+ layered double hydroxides and their calcined products

    International Nuclear Information System (INIS)

    Xiao Ting; Tang Yiwen; Jia Zhiyong; Li Dawei; Hu Xiaoyan; Li Bihui; Luo Lijuan

    2009-01-01

    This paper describes a facile solvothermal method to synthesize self-assembled three-dimensional (3D) Ni 2+ -Fe 3+ layered double hydroxides (LDHs). Flower-like Ni 2+ -Fe 3+ LDHs constructed of thin nanopetals were obtained using ethylene glycol (EG) as a chelating reagent and urea as a hydrolysis agent. The reaction mechanism and self-assembly process are discussed. After calcinating the as-prepared LDHs at 450 0 C in nitrogen gas, porous NiO/NiFe 2 O 4 nanosheets were obtained. This work resulted in the development of a simple, cheap, and effective route for the fabrication of large area Ni 2+ -Fe 3+ LDHs as well as porous NiO/NiFe 2 O 4 nanosheets.

  4. Effectiveness factors for a commercial steam reforming (Ni) catalyst and for a calcined dolomite used downstream biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J; Narvaez, I; Orio, A [Madrid Univ. (Spain). Dept. of Chem. Eng.

    1997-12-31

    A commercial steam reforming catalyst from BASF, the G1-25 S one, and a calcined dolomite, Norte-1, from Cantabria-Spain, have been used, once crushed and sieved to different particle fractions between 1.0 and 4.0 mm. The materials have been tested downstream small pilot biomass gasifiers, bubbling fluidized bed type, gasifying with air and with steam. The Thiele modulus and the effectiveness factor have been calculated at temperatures of 750-850 deg C. It is experimentally shown that diffusion control plays an important part when particle size is larger than ca. 0.5 mm. This has to be taken into account when comparing the quality of the solids for tar elimination. (author) (5 refs.)

  5. Thermal and catalytic cracking of ethylene in presence of CaO, MgO, zeolite and calcined dolomite

    Energy Technology Data Exchange (ETDEWEB)

    Taralas, G; Sjoestroem, K; Jaeraas, S; Bjoernbom, E [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Technology

    1994-12-31

    The subject of the present work is to study the effect of catalysts such as calcined dolomite (CaO.MgO), CaO (quicklime), MgO and Zeolite (EKZ-4) on the cracking of ethylene in the presence and absence of steam. N-heptane, toluene, naphthalene, thiophene have been some suitable model compounds for studies of the thermal and catalytic decomposition of tar. Previous results showed that the reaction scheme of the thermal decomposition of n-heptane was consistent with the high yield of ethylene observed in thermal decomposition of n-heptane. The effect of the reactor wall and the ferric impurities in the dolomite are also subjects of the research in this study. The results may also throw some additional light on the nature of the gas-phase thermal and catalytic reactions occurring in the use of dolomite as tar cracking catalysts. 28 refs

  6. Growth of thin film containing high density ZnO nanorods with low temperature calcinated seed layer

    Science.gov (United States)

    Panda, Rudrashish; Samal, Rudranarayan; Khatua, Lizina; Das, Susanta Kumar

    2018-05-01

    In this work we demonstrate the growth of thin film containing high density ZnO nanorods by using drop casting of the seed layer calcinated at a low temperature of 132 °C. Chemical bath deposition (CBD) method is used to grow the nanorods. X-ray diffraction (XRD) analysis and Field Emission Scanning Electron Microscopy (FESEM) are performed for the structural and morphological characterizations of the nanorods. The average diameter and length of nanorods are found to be 33 nm and 270 nm respectively. The bandgap of the material is estimated to be 3.2 eV from the UV-Visible absorption spectroscopy. The reported method is much more cost-effective and can be used for growth of ZnO nanorods for various applications.

  7. Effectiveness factors for a commercial steam reforming (Ni) catalyst and for a calcined dolomite used downstream biomass gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Corella, J.; Narvaez, I.; Orio, A. [Madrid Univ. (Spain). Dept. of Chem. Eng.

    1996-12-31

    A commercial steam reforming catalyst from BASF, the G1-25 S one, and a calcined dolomite, Norte-1, from Cantabria-Spain, have been used, once crushed and sieved to different particle fractions between 1.0 and 4.0 mm. The materials have been tested downstream small pilot biomass gasifiers, bubbling fluidized bed type, gasifying with air and with steam. The Thiele modulus and the effectiveness factor have been calculated at temperatures of 750-850 deg C. It is experimentally shown that diffusion control plays an important part when particle size is larger than ca. 0.5 mm. This has to be taken into account when comparing the quality of the solids for tar elimination. (author) (5 refs.)

  8. Study of the behavior of aggregate of calcined clay for use in permeable pavements for the city of Manaus

    International Nuclear Information System (INIS)

    Oliveira, M.S.; Vilela, P.A.T.; Araujo, V.S.

    2016-01-01

    Research on the production of ceramic aggregates and their use in paving in the country began in the 80’s in the search for an alternative material that could replace the pebble or crushed stone, studied the clay, considered an abundant mineral resource by virtue of being the predominant soil in this region and which were made synthetic calcinated clay aggregates (ASAC), for their application in permeable paving concrete motivated by the lack of permeable areas. The study consists of the characterization of materials for manufacture of concrete slabs permeable and the assessment of the effects of synthetic aggregate on its properties in fresh and hardened state. The ceramic bodies were subjected to tests of X-ray diffraction, determination of chemical composition and plasticity. The results indicate that the use of synthetic clusters is a viable alternative for the production of porous concrete. (author)

  9. Synthesis of zeolites Na-A and Na-X from tablet compressed and calcinated coal fly ash

    Science.gov (United States)

    Hu, Tao; Gao, Wenyan; Liu, Xin; Zhang, Yifu; Meng, Changgong

    2017-10-01

    Zeolites Na-A and Na-X are important synthetic zeolites widely used for separation and adsorption in industry. It is of great significance to develop energy-efficient routines that can synthesize zeolites Na-A and Na-X from low-cost raw materials. Coal fly ash (CFA) is the major residue from the combustion of coal and biomass containing more than 85% SiO2 and Al2O3, which can readily replace the conventionally used sodium silicate and aluminate for zeolite synthesis. We used Na2CO3 to replace the expensive NaOH used for the calcination of CFA and showed that tablet compression can enhance the contact with Na2CO3 for the activation of CFA through calcination for the synthesis of zeolites Na-A and Na-X under mild conditions. We optimized the control variables for zeolite synthesis and showed that phase-pure zeolite Na-A can be synthesized with CFA at reactant molar ratio, hydrothermal reaction temperature and reaction time of 1.3Na2O: 0.6Al2O3: 1SiO2: 38H2O at 80°C for 6 h, respectively, while phase-pure zeolite Na-X can be synthesized at 2.2Na2O: 0.2Al2O3: 1SiO2: 88H2O at 100°C for 8 h, respectively. The composition, morphology, specific surface area, vibration spectrum and thermogravimetry of synthesized Na-A and Na-X were further characterized.

  10. Molecular dynamics simulations of the effect of NaCl-doping on the calcination characteristics in desulfurization processes

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, T.; Kurita, N.; Naruse, I. [Toyohashi University of Technology, Toyohashi (Japan)

    2003-03-01

    Desulfurization performance of wasted seashells was found to be over twice as high as that of limestone, which was currently used as a desulfurizer in fluidized bed coal combustors. NaCl-doping into limestone was also found to be effective in improving the desulfurization efficiency. From X-ray diffraction (XRD) analyses of calcined seashell, limestone and NaCl-doped limestone, on the other hand, not only the calcined seashell but also the NaCl-doped limestone had strong peaks of CaO crystal, and those two materials also had high desulfurization activity. This improvement was hypothesized to be due to NaCl causing a change in the crystal structure of CaO. In order to elucidate the effect of NaCl addition on the CaO crystal structure in the incineration of CaCO{sub 3} the change of structures was simulated by means of molecular dynamics simulations of CaO. In the simulation one molecule of NaCl was exchanged into one molecule of CaO. A pair correlation functions and the distances between Ca and O atoms, which were obtained by the simulations, were compared with those from the crystal CaO. NaCl-doping affected the crystalization temperature of CaO. The crystallization temperature increased due to adding a little bit of NaCl. From the result of the pair correlation functions obtained in NaCl-doped CaO, the difference of the potential energy of NaCl from that of CaO seemed to contribute to the crystallization of the bulk of CaO. The simulation and experimental results obtained suggested that NaCl-doping contributed to crystallizing the CaO molecules.

  11. Cost Comparison for the Transfer of Select Calcined Waste Canisters to the Monitored Geologic Repository at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    Michael B. Heiser; Clark B. Millet

    2005-01-01

    This report performs a life-cycle cost comparison of three proposed canister designs for the shipment and disposition of Idaho National Laboratory high-level calcined waste currently in storage at the Idaho Nuclear Technology and Engineering Center to the proposed national monitored geologic repository at Yucca Mountain, Nevada. Concept A (2 x 10-ft) and Concept B (2 x 15-ft) canisters are comparable in design, but they differ in size and waste loading options and vary proportionally in weight. The Concept C (5.5 x 17.5-ft) canister (also called the ''super canister''), while similar in design to the other canisters, is considerably larger and heavier than Concept A and B canisters and has a greater wall thickness. This report includes estimating the unique life-cycle costs for the three canister designs. Unique life-cycle costs include elements such as canister purchase and filling at the Idaho Nuclear Technology and Engineering Center, cask preparation and roundtrip consignment costs, final disposition in the monitored geologic repository (including canister off-loading and placement in the final waste disposal package for disposition), and cask purchase. Packaging of the calcine ''as-is'' would save $2.9 to $3.9 billion over direct vitrification disposal in the proposed national monitored geologic repository at Yucca Mountain, Nevada. Using the larger Concept C canisters would use 0.75 mi less of tunnel space, cost $1.3 billion less than 10-ft canisters of Concept A, and would be complete in 6.2 years

  12. Limestone calcined clay cement as a low-carbon solution to meet expanding cement demand in emerging economies

    Directory of Open Access Journals (Sweden)

    Yudiesky Cancio Díaz

    Full Text Available This paper aims at assessing the return on investment and carbon mitigation potentials of five investment alternatives for the Cuban cement industry in a long-term horizon appraisal (15 years. Anticipated growing demand for cement, constrained supply and an urgent need for optimisation of limited capital while preserving the environment, are background facts leading to the present study. This research explores the beneficial contribution of a new available technology, LC3 cement, resulting from the combination of clinker, calcined clay and limestone, with a capacity of replacing up to 50% of clinker in cement. Global Warming Potential (GWP is calculated with Life Cycle Assessment method and the economic investment's payback is assessed through Return on Capital Employed (ROCE approach. Main outcomes show that projected demand could be satisfied either by adding new cement plants—at a high environmental impact and unprofitable performance— or by introducing LC3 strategy. The latter choice allows boosting both the return on investment and the production capacity while reducing greenhouse gas (GHG emissions up to 20–23% compared to business-as-usual practice. Overall profitability for the industry is estimated to overcome BAU scenario by 8–10% points by 2025, if LC3 were adopted. Increasing the production of conventional blended cements instead brings only marginal economic benefits without supporting the needed increase in production capacity. The conducted study also shows that, in spite of the extra capital cost required for the calcination of kaolinite clay, LC3 drops production costs in the range of 15–25% compared to conventional solutions. Keywords: Cement, Alternative, ROCE, CO2, LCA, Investment

  13. Intercalation behavior of amino acids into Zn-Al-layered double hydroxide by calcination-rehydration reaction

    International Nuclear Information System (INIS)

    Aisawa, Sumio; Kudo, Hiroko; Hoshi, Tomomi; Takahashi, Satoshi; Hirahara, Hidetoshi; Umetsu, Yoshio; Narita, Eiichi

    2004-01-01

    The intercalation of amino acids for the Zn-Al-layered double hydroxide (LDH) has been investigated by the calcination-rehydration reaction at 298K using mainly phenylalanine (Phe) as a guest amino acid. The Zn-Al oxide precursor prepared by the calcination of Zn-Al-carbonated LDH at 773K for 2h was used as the host material. The amount of Phe intercalated by the rehydration was remarkably influenced by the initial solution pH and reached ca. 2.7 times for anion exchange capacity (AEC) of the LDH at neutral and weak alkaline solutions, suggesting that Phe was intercalated as amphoteric ion form into the LDH interlayer. As Phe is intercalated for the LDH as monovalent anion in alkaline solution, the amount of Phe intercalated at pH 10.5 corresponded with AEC of the LDH. The solid products were found to have the expanded LDH structure, which confirmed that Phe was intercalated into the LDH interlayer as amphoteric ion or anion form. The basal spacing, d 003 , of the Phe/LDH was 1.58nm at pH 7.0 and 0.80nm at pH 10.5; two kinds of expansion suggested for Phe in the interlayer space as vertical (pH 7.0) and horizontal (pH 10.5) orientations. The intercalation behavior of various amino acids for the LDH was also found to be greatly influenced by the feature of the amino acid side-chain, namely, its carbon-chain length, structure and physicochemical property. In particular, α-amino acids possessing a hydrophobic or negative-charged side-chain were preferentially intercalated for the LDH

  14. Integrated photooxidative-extractive desulfurization system for fuel oil using Cu, Fe and Cu-Fe/TiO2 and eutectic based ionic liquids: Effect of calcination temperature and duration

    Science.gov (United States)

    Zaid, Hayyiratul Fatimah Mohd; Kait, Chong Fai; Mutalib, Mohamed Ibrahim Abdul

    2014-10-01

    Photocatalyts TiO2 doped with Cu, Fe and Cu-Fe metal at different calcination temperature and duration were successfully prepared and characterized. Photocatalytic oxidative desulfurization of model oil containing dibenzothiophene as the sulfur compound (100 ppm) using the prepared photocatalyst was investigated. The photocatalyst calcined at 500°C and duration of 1 h showed the best performance.

  15. Preparation of Calcined Zirconia-Carbon Composite from Metal Organic Frameworks and Its Application to Adsorption of Crystal Violet and Salicylic Acid

    Directory of Open Access Journals (Sweden)

    Zubair Hasan

    2016-03-01

    Full Text Available Zirconia-carbon (ZC composites were prepared via calcination of Zr-based metal organic frameworks, UiO-66 and amino-functionalized UiO-66, under N2 atmosphere. The prepared composites were characterized using a series of instrumental analyses. The surface area of the ZC composites increased with the increase of calcination temperature, with the formation of a graphite oxide phase observed at 900 °C. The composites were used for adsorptive removal of a dye (crystal violet, CV and a pharmaceutical and personal care product (salicylic acid, SA. The increase of the calcination temperature resulted in enhanced adsorption capability of the composites toward CV. The composite calcined at 900 °C exhibited a maximum uptake of 243 mg·g−1, which was much greater than that by a commercial activated carbon. The composite was also effective in SA adsorption (102 mg·g−1, and N-functionalization of the composite further enhanced its adsorption capability (109 mg·g−1. CV adsorption was weakly influenced by solution pH, but was more dependent on the surface area and pore volume of the ZC composite. Meanwhile, SA adsorption showed strong pH dependence, which implies an active role of electrostatic interactions in the adsorption process. Base-base repulsion and hydrogen bonding are also suggested to influence the adsorption of CV and SA, especially for the N-functionalized composite.

  16. Effect of Calcination Temperatures and Mo Modification on Nanocrystalline (γ-χ-Al2O3 Catalysts for Catalytic Ethanol Dehydration

    Directory of Open Access Journals (Sweden)

    Tharmmanoon Inmanee

    2017-01-01

    Full Text Available The mixed gamma and chi crystalline phase alumina (M-Al catalysts prepared by the solvothermal method were investigated for catalytic ethanol dehydration. The effects of calcination temperatures and Mo modification were elucidated. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption, transmission electron microscopy (TEM, and NH3-temperature programmed desorption (NH3-TPD. The catalytic activity was tested for ethylene production by dehydration reaction of ethanol in gas phase at atmospheric pressure and temperature between 200°C and 400°C. It was found that the calcination temperatures and Mo modification have effects on acidity of the catalysts. The increase in calcination temperature resulted in decreased acidity, while the Mo modification on the mixed phase alumina catalyst yielded increased acidity, especially in medium to strong acids. In this study, the catalytic activity of ethanol dehydration to ethylene apparently depends on the medium to strong acid. The mixed phase alumina catalyst calcined at 600°C (M-Al-600 exhibits the complete ethanol conversion having ethylene yield of 98.8% (at 350°C and the Mo-modified catalysts promoted dehydrogenation reaction to acetaldehyde. This can be attributed to the enhancement of medium to strong acid with metal sites of catalyst.

  17. Manufacture of barium hexaferrite (BaO3.98Fe2O3) from iron oxide waste of grinding process by using calcination process

    Science.gov (United States)

    Idayanti, N.; Dedi; Kristiantoro, T.; Mulyadi, D.; Sudrajat, N.; Alam, G. F. N.

    2018-03-01

    The utilization of iron oxide waste of grinding process as raw materials for making barium hexaferrite has been completed by powder metallurgy method. The iron oxide waste was purified by roasting at 800 °C temperature for 3 hours. The method used varying calcination temperature at 1000, 1100, 1200, and 1250 °C for 3 hours. The starting iron oxide waste (Fe2O3) and barium carbonate (BaCO3) were prepared by mol ratio of Fe2O3:BaCO3 from the formula BaO3.98Fe2O3. Some additives such as calcium oxide (CaO), silicon dioxide (SiO2), and polyvinyl alcohol (PVA) were added after calcination process. The samples were formed at the pressure of 2 ton/cm2 and sintered at the temperature of 1250 °C for 1 hour. The formation of barium hexaferrite compounds after calcination is determined by X-Ray diffraction. The magnetic properties were observed by Permagraph-Magnet Physik with the optimum characteristic at calcination temperature of 1250 °C with the induction of remanence (Br) = 1.38 kG, coercivity (HcJ) = 4.533 kOe, product energy maximum (BHmax) = 1.086 MGOe, and density = 4.33 g/cm3.

  18. Aqueous chemical route synthesis and the effect of calcination temperature on the structural and optical properties of ZnO nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohammad Ramzan Parra

    2014-10-01

    Full Text Available This article reports the controlled size of ZnO nanoparticles synthesized via simple aqueous chemical route without the involvement of any capping agent. The effect of different calcination temperatures on the size of the ZnO nanoparticles was investigated. X-ray diffraction (XRD results indicated that all the samples have crystalline wurtzite phase, and peak broadening analysis was used to evaluate the average crystallite size and lattice strain using Scherrer's equation and Williamson–Hall (W–H method. Morphology and elemental compositions were investigated using atomic force microscopy (AFM and scanning electron microscopy (SEM with energy-dispersive X-ray (EDX spectroscopy. The average crystallite size of ZnO nanoparticles estimated from Scherrer's formula and W–H analysis was found to increase with the increase in calcination temperature. These results were in good agreement with AFM results. Optical properties were investigated using UV–vis spectroscopy in diffused reflectance (DR mode, with a sharp increase in reflectivity at 375 nm and the material has a strong reflective characteristic after 420 nm at 500 °C calcination temperature. Furthermore, photoluminescence spectroscopic results revealed intensive ultraviolet (UV emission with reduced defect concentrations and a slight shifting in band gap energies with increased calcination temperature from 200 °C to 500 °C. This study suggests that the as-prepared ZnO nanoparticles with bandgap tunability might be utilized as window layer in optoelectronic devices.

  19. Removal of indigo carmine and green bezanyl-F2B from water using calcined and uncalcined Zn/Al + Fe layered double hydroxide

    Directory of Open Access Journals (Sweden)

    Hassiba Bessaha

    2017-06-01

    Full Text Available Layered double hydroxide Zn/(Al + Fe with a molar ratio of 3:(0.85 + 0.15, designated as ZAF-HT, was synthetized by co-precipitation. Its calcined product CZAF was obtained by heat treatment of ZAF-HT at 500°C. The calcined and uncalcined materials were used to remove the acid dyes indigo carmine (IC and green bezanyl-F2B (F2B from water in batch mode. The synthetized materials were characterized by X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller analysis, Fourier transform infra-red spectroscopy and thermogravimetric/differential thermal analysis. The sorption kinetic data fitted a pseudo-second-order model. The adsorbed amounts of the calcined material were much larger than ZAF-HT. The maximum adsorption capacity of CZAF was found to be 617.3 mg g−1 for IC and 1,501.4 mg g−1 for F2B. The isotherms showed that the removal of IC and F2B by ZAF-HT and CZAF could be described by a Langmuir model. The thermodynamic parameters were also calculated. The negative values of standard free energy ΔG° indicate the spontaneity of sorption process. The reuse of CZAF was studied for both dyes and the calcined material showed a good stability for four thermal cycles.

  20. Influence of calcination temperature on the morphology and energy storage properties of cobalt oxide nanostructures directly grown over carbon cloth substrates

    KAUST Repository

    Baby, Rakhi Raghavan

    2013-09-23

    Nanostructured and mesoporous cobalt oxide (Co3O4) nanowire in flower-like arrangements have been directly grown over flexible carbon cloth collectors using solvothermal synthesis for supercapacitor applications. Changes in the morphology and porosity of the nanowire assemblies have been induced by manipulating the calcination temperature (200–300 °C) of the one-dimensional (1-D) structures, resulting in significant impact on their surface area and pseudocapacitive properties. As the calcination temperature increases from 200 to 250 °C, the flower morphology gradually modifies to the point where the electrolyte could access almost all the nanowires over the entire sample volume, resulting in an increase in specific capacitance from 334 to 605 Fg−1, depending on the nanowire electrode morphology. The 300 °C calcination results in the breakdown of the mesoporous morphology and decreases the efficiency of electrolyte diffusion, resulting in a drop in pseudocapacitance after 300 °C. A peak energy density of 44 Wh kg−1 has been obtained at a power density of 20 kW kg−1 for the 250 °C calcined sample.

  1. Negative Effect of Calcination to Catalytic Performance of Coal Char-loaded TiO2 Catalyst in Styrene Oxidation with Hydrogen Peroxide as Oxidant

    Directory of Open Access Journals (Sweden)

    Mukhamad Nurhadi

    2018-01-01

    How to Cite: Nurhadi, M., Kusumawardani, R., Nur, H. (2018. Negative Effect of Calcination to Catalytic Performance of Coal Char-loaded TiO2 Catalyst in Styrene Oxidation with Hydrogen Peroxide as Oxidant. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 113-118 (doi:10.9767/bcrec.13.1.1171.113-118

  2. Comparison of the rotary calciner-metallic melter and the slurry-fed ceramic melter technologies for vitrifying West Valley high-level wastes

    International Nuclear Information System (INIS)

    Chapman, C.C.

    1983-01-01

    Two processes which are believed applicable and available for vitrification of West Valley's high-level (HLW) wastes were technically evaluated and compared. The rotary calciner-metallic melter (AVH) and the slurry-fed ceramic melter (SFCM) were evaluated under the following general categories: process flow sheet, remote operability, safety and environmental considerations, and estimated cost and schedules

  3. Influence of calcination temperature on the morphology and energy storage properties of cobalt oxide nanostructures directly grown over carbon cloth substrates

    KAUST Repository

    Baby, Rakhi Raghavan; Chen, Wei; Cha, Dong Kyu; Alshareef, Husam N.

    2013-01-01

    Nanostructured and mesoporous cobalt oxide (Co3O4) nanowire in flower-like arrangements have been directly grown over flexible carbon cloth collectors using solvothermal synthesis for supercapacitor applications. Changes in the morphology and porosity of the nanowire assemblies have been induced by manipulating the calcination temperature (200–300 °C) of the one-dimensional (1-D) structures, resulting in significant impact on their surface area and pseudocapacitive properties. As the calcination temperature increases from 200 to 250 °C, the flower morphology gradually modifies to the point where the electrolyte could access almost all the nanowires over the entire sample volume, resulting in an increase in specific capacitance from 334 to 605 Fg−1, depending on the nanowire electrode morphology. The 300 °C calcination results in the breakdown of the mesoporous morphology and decreases the efficiency of electrolyte diffusion, resulting in a drop in pseudocapacitance after 300 °C. A peak energy density of 44 Wh kg−1 has been obtained at a power density of 20 kW kg−1 for the 250 °C calcined sample.

  4. Structural, optical and morphological properties of post-growth calcined TiO{sub 2} nanopowder for opto-electronic device application: Ex-situ studies

    Energy Technology Data Exchange (ETDEWEB)

    Sathyaseelan, B., E-mail: bsseelan03@gmail.com [Dept of Physics, University College of Engineering Arni (A Constituent College of Anna University Chennai) Arni 632326, Tamil Nadu (India); Manikandan, E., E-mail: maniphysics@gmail.com [Central Research Laboratory, Sree Balaji Medical College & Hospital, Bharath University, BIHER, Chrompet, Chennai 600044, Tamil Nadu (India); UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); Lakshmanan, V. [Dept of Physics, A.C.T College of Engineering & Technology, Nelvoy 603107 Kancheepuram (Dt), Tamil Nadu (India); Baskaran, I. [Dept of Physics, Arignar Anna Government Arts College, Cheyyar 604407, Tamil Nadu (India); Sivakumar, K. [Dept of Physics, Anna University, Chennai 600025, Tamil Nadu (India); Ladchumananandasivam, Rasiah [Dept of Textile Engineering & Post Graduate Programme in Mechanical Engineering Centre of Technology, Federal University of Rio Grande do Norte, Natal (Brazil); Kennedy, J. [UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa); The MacDiarmid Institute for Advanced Materials and Nanotechnology, PO Box 600, Wellington (New Zealand); Maaza, M., E-mail: maaza@tlabs.ac.za [UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria (South Africa)

    2016-06-25

    Nanocrystalline TiO{sub 2} powders have been selectively prepared by the simple combustion reaction method using urea as a fuel. The crystalline powder was obtained using a silica basin heated directly on a hot plate at 500 °C until self-ignition occurred. After combustion process, the calcined products were obtained by heating the as-prepared powders for 1 h in air atmosphere at various sintering temperatures [500–900 °C]. The obtained nanopowder materials were systematically characterized by X-day diffraction (XRD), micro-Raman, UV–visible absorption (UV–vis), and Fourier transform infrared (FT-IR) spectroscopics. Powder XRD pattern shows the good agreement rutile phase structured TiO{sub 2} and the sharp diffraction peaks indicates good for crystallinity. The size of a symmetry of the nanoparticles have been measured with aid of a scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), and Brunauer, Emmett and Teller (BET) surface studies. The crystallinity of the powders was found to increase with respect to calcination temperatures. The average specific surface area of the particle was probed using gas adsorption–desorption measurements. Raman spectroscopy experiment was performed to ascertain the nature of TiO{sub 2} powder quality. UV–vis absorption spectra results showed the changes in the absorption edges of TiO{sub 2} report to increasing the calcinations temperatures. - Highlights: • TiO{sub 2} Nanocrystalline powders were prepared by simple combustion reaction method. • Calcined TiO{sub 2} nanopowder obtained by heating for 1 hr in air atmosphere at 500–900 °C. • Systematic characterization employed by XRD, micro-Raman, Optical, SEM, HRTEM. • The size symmetry of nanoparticles measured by electron microscopes BET methods. • Calcinations raises the crystallinity size enhanced for future opto-electronic devices.

  5. Effect of calcination temperature on the structural, optical and magnetic properties of pure and Fe-doped ZnO nanoparticles

    Directory of Open Access Journals (Sweden)

    Pal Singh Raminder Preet

    2016-06-01

    Full Text Available In the present study, pure ZnO and Fe-doped ZnO (Zn0.97Fe0.03O nanoparticles were synthesized by simple coprecipitation method with zinc acetate, ferric nitrate and sodium hydroxide precursors. Pure ZnO and Fe-doped ZnO were further calcined at 450 °C, 600 °C and 750 °C for 2 h. The structural, morphological and optical properties of the samples were characterized by X-ray diffractometer (XRD, scanning electron microscope (SEM, energy dispersive spectroscopy (EDS and UV-Vis absorption spectroscopy. The X-ray diffraction studies revealed that the as-synthesized pure and doped ZnO nanoparticles have hexagonal wurtzite structure. The average crystallite size was calculated using Debye-Scherrer’s formula. The particle size was found to be in nano range and increased with an increase in calcination temperature. SEM micrographs confirmed the formation of spherical nanoparticles. Elemental compositions of various elements in pure and doped ZnO nanoparticles were determined by EDX spectroscopy. UV-Vis absorption spectra showed red shift (decrease in band gap with increasing calcination temperature. Effect of calcination on the magnetic properties of Fe-doped ZnO sample was also studied using vibrating sample magnetometer (VSM. M-H curves at room temperature revealed that coercivity and remanent polarization increase with an increase in calcination temperature from 450 °C to 750 °C, whereas reverse effect was observed for magnetization saturation.

  6. Increased photocatalytic activity of NiO and ZnO in photodegradation of a model drug aqueous solution: Effect of coupling, supporting, particles size and calcination temperature

    Energy Technology Data Exchange (ETDEWEB)

    Derikvandi, Hadis [Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Iran (Iran, Islamic Republic of); Young Researchers and Elite Club, Shahreza Branch, Islamic Azad University, Shahreza (Iran, Islamic Republic of); Nezamzadeh-Ejhieh, Alireza, E-mail: arnezamzadeh@iaush.ac.ir [Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Iran (Iran, Islamic Republic of); Young Researchers and Elite Club, Shahreza Branch, Islamic Azad University, Shahreza (Iran, Islamic Republic of); Razi Chemistry Research Center (RCRC), Shahreza Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2017-01-05

    Highlights: • Increased photoactivity of hybridized/supported NiO-ZnO whit respect to monocomponent one. • Strong dependence of photocatalytic activity of NiO-ZnO to calcination temperature. • Calcination temperature varied the crystallite forms of the semiconductors. • Red shifts in band gaps of the supported coupled semiconductors whit respect to monocomponent one. - Abstract: Mechanically ball-mill prepared clinoptilolite nanoparticles (NC) were used for increasing photocatalytic activity of NiO and ZnO as alone and binary systems. The semiconductors were supported onto the zeolite during calcination of Ni(II)-Zn(II)-exchanged NC at different calcinations temperatures. XRD, FTIR, SEM-EDX, X-ray mapping, DRS, TEM and BET techniques were used for characterization of the samples. The calcined catalysts at 400 °C for 4 h showed the best photocatalytic activity for metronidazole (MNZ) in aqueous solution. The mole ratio of ZnO/NiO affected the photodegradation efficiency because activity of the coupled catalysts depends to the both e/h production and electron scavenging processes. In the used system, NiO acted as e/h production source and ZnO as an electron sink. Red shifts in band gaps of the supported coupled semiconductors was observed whit respect to monocomponent one, confirming formation of nanoparticles of the semiconductors onto the zeolitic bed. The best activities were obtained for the NiO{sub 1.3}–ZnO{sub 1.5}/NC (NZ-NC) and NiO{sub 0.7}–ZnO{sub 4.3}/NC (NZ{sub 3}-NC) catalysts at pH 3, 1.2 g L{sup −1} of the catalysts and 1 g L{sup −1} of MNZ.

  7. Facile synthesis of both needle-like and spherical hydroxyapatite nanoparticles: Effect of synthetic temperature and calcination on morphology, crystallite size and crystallinity

    International Nuclear Information System (INIS)

    Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G.; Premalal, E.V.A.; Herath, H.M.T.U.; Mahalingam, S.; Edirisinghe, M.; Rajapakse, R.P.V.J.; Rajapakse, R.M.G.

    2014-01-01

    Synthetic hydroxyapatite (HA) nanoparticles, that mimic natural HA, are widely used as biocompatible coatings on prostheses to repair and substitute human bones. In this study, HA nanoparticles are prepared by precipitating them from a precursor solution containing calcium sucrate and ammonium dihydrogen orthophosphate, at a Ca/P mole ratio of 1.67:1, at temperatures, ranging from 10 °C to 95 °C. A set of products, prepared at different temperatures, is analyzed for their crystallinity, crystallite size, morphology, thermal stability and composition, by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopic techniques, while the other set is analyzed after calcining the respective products, soon after their synthesis, for 3 h, at 700 °C. The as-prepared products, after 2 h of drying, without any calcination, are not crystalline, but they grow very slowly into needle-like morphologies, as they are ripened with time. The percentage crystallinity of the final products increases from 15% to 52%, with increasing the preparative temperature. The calcined samples always produce spherical nanoparticles of essentially the same diameter, between 90 nm and 100 nm, which does not change due to aging and preparative temperatures. Therefore, the same method can be utilized to synthesize both spherical and needle-like nanoparticles of hydroxyapatite, with well-defined sizes and shapes. The ability to use readily available cheap raw materials, for the synthesis of such well-defined crystallites of hydroxyapatite, is an added advantage of this method, which may be explored further for the scaling up of the procedures to suit to industrial scale synthesis of such hydroxyapatite nanoparticles. - Highlights: • Hydroxyapatite nanoparticles are synthesized using a simple precipitation method. • Both needle-like and spherical hydroxyapatite nanoparticles are synthesized. • The prepared

  8. Facile synthesis of both needle-like and spherical hydroxyapatite nanoparticles: Effect of synthetic temperature and calcination on morphology, crystallite size and crystallinity

    Energy Technology Data Exchange (ETDEWEB)

    Wijesinghe, W.P.S.L.; Mantilaka, M.M.M.G.P.G. [Department of Chemistry, Faculty of Science, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Post-graduate Institute of Science, P.O. Box: 25, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Premalal, E.V.A. [Department of Materials Science, Shizuoka University, Johoku, Naka-ku Hamamatsu, 432-8011 (Japan); Herath, H.M.T.U. [Department of Medical Laboratory Science, Faculty of Allied Health Sciences, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Mahalingam, S.; Edirisinghe, M. [Department of Mechanical Engineering, University College London, London WC1E 7JE (United Kingdom); Rajapakse, R.P.V.J. [Department of Veterinary Pathobiology, Faculty of Veterinary, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Rajapakse, R.M.G., E-mail: rmgr@pdn.ac.lk [Department of Chemistry, Faculty of Science, University of Peradeniya, Peradeniya 20400 (Sri Lanka); Post-graduate Institute of Science, P.O. Box: 25, University of Peradeniya, Peradeniya 20400 (Sri Lanka)

    2014-09-01

    Synthetic hydroxyapatite (HA) nanoparticles, that mimic natural HA, are widely used as biocompatible coatings on prostheses to repair and substitute human bones. In this study, HA nanoparticles are prepared by precipitating them from a precursor solution containing calcium sucrate and ammonium dihydrogen orthophosphate, at a Ca/P mole ratio of 1.67:1, at temperatures, ranging from 10 °C to 95 °C. A set of products, prepared at different temperatures, is analyzed for their crystallinity, crystallite size, morphology, thermal stability and composition, by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopic techniques, while the other set is analyzed after calcining the respective products, soon after their synthesis, for 3 h, at 700 °C. The as-prepared products, after 2 h of drying, without any calcination, are not crystalline, but they grow very slowly into needle-like morphologies, as they are ripened with time. The percentage crystallinity of the final products increases from 15% to 52%, with increasing the preparative temperature. The calcined samples always produce spherical nanoparticles of essentially the same diameter, between 90 nm and 100 nm, which does not change due to aging and preparative temperatures. Therefore, the same method can be utilized to synthesize both spherical and needle-like nanoparticles of hydroxyapatite, with well-defined sizes and shapes. The ability to use readily available cheap raw materials, for the synthesis of such well-defined crystallites of hydroxyapatite, is an added advantage of this method, which may be explored further for the scaling up of the procedures to suit to industrial scale synthesis of such hydroxyapatite nanoparticles. - Highlights: • Hydroxyapatite nanoparticles are synthesized using a simple precipitation method. • Both needle-like and spherical hydroxyapatite nanoparticles are synthesized. • The prepared

  9. Continuous plutonium(IV) oxalate precipitation, filtration, and calcination process. [From product streams from Redox, Purex, or Recuplex solvent extraction plants

    Energy Technology Data Exchange (ETDEWEB)

    Beede, R L

    1956-09-27

    A continuous plutonium (IV) oxalate precipitation, filtration, and calcination process has been developed. Continuous and batch decomposition of the oxalate in the filtrates has been demonstrated. The processes have been demonstrated in prototype equipment. Plutonium (IV) oxalate was precipitated continuously at room temperature by the concurrent addition of plutonium (IV) nitrate feed and oxalic acid into the pan of a modified rotary drum filter. The plutonium (IV) oxalate was calcined to plutonium dioxide, which could be readily hydrofluorinated. Continuous decomposition of the oxalate in synthetic plutonium (IV) oxalate filtrates containing plutonium (IV) oxalate solids was demonstrated using co-current flow in a U-shaped reactor. Feeds containing from 10 to 100 g/1 Pu, as plutonium (IV) nitrate, and 1.0 to 6.5 M HNO/sub 3/, respectively, can be processed. One molar oxalic acid is used as the precipitant. Temperatures of 20 to 35/sup 0/C for the precipitation and filtration are satisfactory. Plutonium (IV) oxalate can be calcined at 300 to 400/sup 0/C in a screw-type drier-calciner to plutonium dioxide and hydrofluorinated at 450 to 550/sup 0/C. Plutonium dioxide exceeding purity requirements has been produced in the prototype equipment. Advantages of continuous precipitation and filtration are: uniform plutonium (IV) oxalate, improved filtration characteristics, elimination of heating and cooling facilities, and higher capacities through a single unit. Advantages of the screw-type drier-calciner are the continuous production of an oxide satisfactory for feed for the proposed plant vibrating tube hydrofluorinator, and ease of coupling continuous precipitation and filtration to this proposed hydrofluorinator. Continuous decomposition of oxalate in filtrates offers advantages in decreasing filtrate storage requirements when coupled to a filtrate concentrator. (JGB)

  10. In Situ IR Characterization of CO Interacting with Rh Nanoparticles Obtained by Calcination and Reduction of Hydrotalcite-Type Precursors

    Directory of Open Access Journals (Sweden)

    F. Basile

    2011-01-01

    Full Text Available Supported Rh nanoparticles obtained by reduction in hydrogen of severely calcined Rh/Mg/Al hydrotalcite-type (HT phases have been characterized by FT-IR spectroscopy of adsorbed CO [both at room temperature (r.t. and nominal liquid nitrogen temperature] and Transmission Electron Microscopy (TEM. The effect of reducing temperature has been investigated, showing that Rh crystal size increases from 1.4 nm to 1.8 nm when the reduction temperature increases from 750°C to 950°C. The crystal growth favours the formation of bridged CO species and linear monocarbonyl species with respect to gem-dicarbonyl species; when CO adsorbs at r.t., CO disproportionation occurs on Rh and it accompanies the formation of RhI(CO2. The role of interlayer anions in the HT precursors to affect the properties of the final materials has been also investigated considering samples prepared from silicate-instead of carbonate-containing precursors. In this case, formation of RhI(CO2 and CO disproportionation do not occur, and this evidence is discussed in terms of support effect.

  11. PHYSICAL, CHEMICAL, AND STRUCTURAL EVOLUTION OF ZEOLITE-CONTAINING WASTE FORMS PRODUCED FROM METAKAOLINITE AND CALCINED HLW

    International Nuclear Information System (INIS)

    Pareizs, J. M.; Jantzenm, C.M.

    2000-01-01

    Natural and synthetic zeolites are extremely versatile materials. They can adsorb a variety of liquids and gases, and also take part in cation exchange reactions. Zeolites have the ability to sequester ions in lattice positions or within their networks of channels and voids. The zeolites can host alkali, alkaline earth and a variety of higher valance cations. As such they may be a viable alternative for immobilization of low activity waste (LAW) salts and calcines. The process for synthesizing zeolites is well documented for pure starting materials. A reactive aluminosilicate is reacted with an alkaline hydroxide at low temperature (<300 C) to form a zeolite. Processing time and temperature and specific reactants determine the type of zeolite formed. Zeolites are easy to make, and can be synthesized from a wide variety of natural and man made materials. However, relatively little is known about the process if one of the starting materials is a poorly characterized complex mixture of oxides (waste) containing nearly every element in the periodic table. The purpose of this work is to develop a clearer understanding of the advantages and limitations of producing a zeolite waste form from radioactive waste. Dr. M. W. Grutzeck at the Pennsylvania State University is investigating the production of a zeolite waste form using nonradioactive simulants. Dr. C. M. Jantzen and J. M. Pareizs at the Savannah River Technology Center will use the results from simulant work as a starting point for producing a zeolite waste form from an actual Savannah River Site radioactive waste stream

  12. Hydration mechanism and leaching behavior of bauxite-calcination-method red mud-coal gangue based cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Na; Li, Hongxu [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction, University of Science and Technology Beijing, Beijing 100083 (China); Liu, Xiaoming, E-mail: liuxm@ustb.edu.cn [School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Rare and Precious Metals Green Recycling and Extraction, University of Science and Technology Beijing, Beijing 100083 (China)

    2016-08-15

    Highlights: • Nanocrystalline regions in size of ∼5 nm were found in the amorphous C-A-S-H gel. • A hydration model was proposed to clarify the hydration mechanism. • The developed cementitious materials are environmentally acceptable. - Abstract: A deep investigation on the hydration mechanism of bauxite-calcination-method red mud-coal gangue based cementitious materials was conducted from viewpoints of hydration products and hydration heat analysis. As a main hydration product, the microstructure of C-A-S-H gel was observed using high resolution transmission electron microscopy. It was found that the C-A-S-H gel is composed of amorphous regions and nanocrystalline regions. Most of regions in the C-A-S-H gel are amorphous with continuous distribution, and the nanocrystalline regions on scale of ∼5 nm are dispersed irregularly within the amorphous regions. The hydration heat of red mud-coal gangue based cementitious materials is much lower than that of the ordinary Portland cement. A hydration model was proposed for this kind of cementitious materials, and the hydration process mainly consists of four stages which are dissolution of materials, formation of C-A-S-H gels and ettringite, cementation of hydration products, and polycondensation of C-A-S-H gels. There are no strict boundaries among these four basic stages, and they proceed crossing each other. Moreover, the leaching toxicity tests were also performed to prove that the developed red mud-coal gangue based cementitious materials are environmentally acceptable.

  13. Rietveld profile analysis of calcined AlPO/sub 4/-11 using pulsed neutron powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, J.W. Jr.; Pluth, J.J.; Smith, J.V.

    1988-08-01

    Aluminium phosphate, AlPO/sub 4/, M/sub r/=121.95, orthorhombic, Icmm (disordered Al, P), Icm2 (ordered Al, P), a=13.5333(8), b=18.4845(10), c=8.3703(4) A, V=2094 A/sup 3/, Z=20, D/sub x/=1.93 g cm/sup -3/, T approx. = 295 K, R/sub wp/=0.031, R/sub F//sup 2/=0.109 (Icmm) and R/sub wp/=0.027, R/sub F//sup 2/=0.058 (Icm2) for 1017 independent reflections. Sample calcined at 873 K and dehydrated at 573 K. Time-of-flight neutron powder diffraction data were taken on the GPPD diffractometer at the Argonne National Laboratory Intense Pulsed Neutron Source. The structure was refined by Rietveld profile analysis in the range d=0.86-3.91 A in two space groups: Icmm assuming no ordering of Al and P, and Icm2 assuming strict alternation of Al and P on tetrahedral nodes. (orig./BHo).

  14. Palm oil biodiesel synthesized with potassium loaded calcined hydrotalcite and effect of biodiesel blend on elastomer properties

    Energy Technology Data Exchange (ETDEWEB)

    Trakarnpruk, Wimonrat; Porntangjitlikit, Suriya [Petrochemistry and Polymer Science, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330 (Thailand)

    2008-07-15

    Biodiesel was prepared from palm oil by transesterification with methanol in the presence of 1.5%K loaded-calcined Mg-Al hydrotalcite. Fatty acid methyl esters content of 96.9% and methyl ester yield of 86.6% were achieved using a 30:1 methanol to oil molar ratio at 100{sup o}C for 6 h and 7 wt% catalyst. The biodiesel was characterized and its impact on elastomer properties was evaluated. The compatibility of B10 diesel blend (10% biodiesel) with six types of elastomers commonly found in fuel systems (NBR, HNBR, NBR/PVC, acrylic rubber, co-polymer FKM, and terpolymer FKM) were investigated. The physical properties of elastomers after immersion in tested fuels (for 22, 670, and 1008 h at 100{sup o}C) were measured according to American Society of Testing and Materials (ASTM). These include swelling (mass change and volume change), hardness, tensile and elongation, as well as the dynamic mechanical property. The results showed that properties of NBR, NBR/PVC and acrylic rubber were affected more than other elastomers. This is due to the absorption and dissolving of biodiesel by rubber in these samples. Co-polymer FKM and terpolymer FKM which are fluoroelastomers show little property change. (author)

  15. Feasibility analysis of As(III) removal in a continuous flow fixed bed system by modified calcined bauxite (MCB)

    International Nuclear Information System (INIS)

    Bhakat, P.B.; Gupta, A.K.; Ayoob, S.

    2007-01-01

    This study examine the feasibility of As(III) removal from aqueous environment by an adsorbent, modified calcined bauxite (MCB) in a continuous flow fixed bed system. MCB exhibited excellent adsorption capacity of 520.2 mg/L (0.39 mg/g) with an adsorption rate constant 0.7658 L/mg h for an influent As(III) concentration of 1 mg/L. In a 2 cm diameter continuous flow fixed MCB bed, a depth of only 1.765 cm was found necessary to produce effluent As(III) concentration of 0.01 mg/L, from an influent of 1 mg/L at a flow rate of 8 mL/min. Also, bed heights of 10, 20, and 30 cm could treat 427.85, 473.88 and 489.17 bed volumes of water, respectively, to breakthrough. A reduction in adsorption capacity of MCB was observed with increase in flow rates. The theoretical service times evaluated from bed depth service time (BDST) approach for different flow rates and influent As(III) concentrations had shown good correlation with the corresponding experimental values. The theoretical breakthrough curve developed from constantly mixed batch reactor (CMBR) isotherm data also correlated well with experimental breakthrough curve

  16. Hydration mechanism and leaching behavior of bauxite-calcination-method red mud-coal gangue based cementitious materials

    International Nuclear Information System (INIS)

    Zhang, Na; Li, Hongxu; Liu, Xiaoming

    2016-01-01

    Highlights: • Nanocrystalline regions in size of ∼5 nm were found in the amorphous C-A-S-H gel. • A hydration model was proposed to clarify the hydration mechanism. • The developed cementitious materials are environmentally acceptable. - Abstract: A deep investigation on the hydration mechanism of bauxite-calcination-method red mud-coal gangue based cementitious materials was conducted from viewpoints of hydration products and hydration heat analysis. As a main hydration product, the microstructure of C-A-S-H gel was observed using high resolution transmission electron microscopy. It was found that the C-A-S-H gel is composed of amorphous regions and nanocrystalline regions. Most of regions in the C-A-S-H gel are amorphous with continuous distribution, and the nanocrystalline regions on scale of ∼5 nm are dispersed irregularly within the amorphous regions. The hydration heat of red mud-coal gangue based cementitious materials is much lower than that of the ordinary Portland cement. A hydration model was proposed for this kind of cementitious materials, and the hydration process mainly consists of four stages which are dissolution of materials, formation of C-A-S-H gels and ettringite, cementation of hydration products, and polycondensation of C-A-S-H gels. There are no strict boundaries among these four basic stages, and they proceed crossing each other. Moreover, the leaching toxicity tests were also performed to prove that the developed red mud-coal gangue based cementitious materials are environmentally acceptable.

  17. Physical, chemical, and structural evolution of zeolite-containing waste forms produced from metakaolinite and calcined HLW

    International Nuclear Information System (INIS)

    Pareizs, J.M.

    2000-01-01

    Natural and synthetic zeolites are extremely versatile materials. They can adsorb a variety of liquids and gases, and also take part in cation exchange reactions. Zeolites have the ability to sequester ions in lattice positions or within their networks of channels and voids. The zeolites can host alkali, alkaline earth and a variety of higher valence cations. As such they may be a viable alternative for immobilization of low activity waste (LAW) salts and calcines. The process for synthesizing zeolites is well documented for pure starting materials. A reactive aluminosilicate is reacted with an alkaline hydroxide at low temperature to form a zeolite. Processing time and temperature and specific reactants determine the type of zeolite formed. Zeolites are easy to make, and can be synthesized from a wide variety of natural and man made materials. However, relatively little is known about the process if one of the starting materials is a poorly characterized complex mixture of oxides (waste) containing nearly every element in the periodic table. The purpose of this work is to develop a clearer understanding of the advantages and limitations of producing a zeolite waste form from radioactive waste. Dr. M. W. Grutzeck at the Pennsylvania State University is investigating the production of a zeolite waste form using non-radioactive simulants. Dr. C. M. Jantzen and J. M. Pareizs at the Savannah River Technology Center will use the results from simulant work as a starting point for producing a zeolite waste form from an actual Savannah River Site radioactive waste stream

  18. Influence of calcination temperature in pozolanicity of gray sugar cane bagasse; Influencia da temperatura de calcinacao na pozolanicidade da cinza de bagaco de cana-de-acucar (CBCA))

    Energy Technology Data Exchange (ETDEWEB)

    Santos, T.A.; Argolo, R.A.; Andrade, H.M.C.; Ribeiro, D.V., E-mail: tiagoassuncao@hotmail.com [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil)

    2016-07-01

    BCA (Sugar Cane Bagasse) is burned in boilers in the process of electricity cogeneration causing the generation of CBCA (Gray Sugar Cane Bagasse), which is the final residue of sucroalcooeira industry. Currently, several studies seek alternative materials that can replace Portland cement, promoting discussions on the use of pozzolanic materials in cementitious matrices. Thus, this research seeks to analyze the pozzolanicity the CBCA, obtained by calcining the residue at different temperatures, to be determined by TG / DTG and DTA tests. For analysis of pozzolanicity these ashes were used electrical conductivity techniques, chemical titration NP EN 196-5, chapelle modified NBR 15895/2010 and the IAP method (Activity Index pozzolanic NBR:5752). The results obtained during the study demostraramm no difference between the ash calcined at temperatures of 500 ° C, 600 ° C and 700 ° C. (author)

  19. Superb adsorption capacity of hierarchical calcined Ni/Mg/Al layered double hydroxides for Congo red and Cr(VI) ions

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Chunsheng [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); College of Environmental & Safety Engineering, Changzhou University, Changzhou 213164 (China); Zhu, Xiaofeng [College of Environmental & Safety Engineering, Changzhou University, Changzhou 213164 (China); Zhu, Bicheng; Jiang, Chuanjia; Le, Yao [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Yu, Jiaguo, E-mail: jiaguoyu@yahoo.com [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China); Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2017-01-05

    Highlights: • Ni/Mg/Al layered double hydroxides (NMA-LDHs) synthesized. • NMA-LDHs with hierarchically hollow microsphere structure. • Calcined NMA-LDHs have large adsorption capacities for CR and Cr(VI) ions. - Abstract: The preparation of hierarchical porous materials as catalysts and sorbents has attracted much attention in the field of environmental pollution control. Herein, Ni/Mg/Al layered double hydroxides (NMA-LDHs) hierarchical flower-like hollow microspheres were synthesized by a hydrothermal method. After the NMA-LDHs was calcined at 600 °C, NMA-LDHs transformed into Ni/Mg/Al layered double oxides (NMA-LDOs), which maintained the hierarchical flower-like hollow structure. The crystal phase, morphology, and microstructure of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy elemental mapping, Fourier transform infrared spectroscopy, and nitrogen adsorption−desorption methods. Both the calcined and non-calcined NMA-LDHs were examined for their performance to remove Congo red (CR) and hexavalent chromium (Cr(VI)) ions in aqueous solution. The maximum monolayer adsorption capacities of CR and Cr(VI) ions over the NMA-LDOs sample were 1250 and 103.4 mg/g at 30 °C, respectively. Thermodynamic studies indicated that the adsorption process was endothermic in nature. In addition, the addition of coexisting anions negatively influenced the adsorption capacity of Cr(VI) ions, in the following order: CO{sub 3}{sup 2−} > SO{sub 4}{sup 2−} > H{sub 2}PO{sub 4}{sup −} > Cl{sup −}. This work will provide new insight into the design and fabrication of advanced adsorption materials for water pollutant removal.

  20. Choice of precipitant and calcination temperature of precursor for synthesis of NiCo2O4 for control of CO-CH4 emissions from CNG vehicles.

    Science.gov (United States)

    Trivedi, Suverna; Prasad, Ram

    2018-03-01

    Compressed natural gas (CNG) is most appropriate an alternative of conventional fuel for automobiles. However, emissions of carbon-monoxide and methane from such vehicles adversely affect human health and environment. Consequently, to abate emissions from CNG vehicles, development of highly efficient and inexpensive catalysts is necessary. Thus, the present work attempts to scan the effects of precipitants (Na 2 CO 3 , KOH and urea) for nickel cobaltite (NiCo 2 O 4 ) catalysts prepared by co-precipitation from nitrate solutions and calcined in a lean CO-air mixture at 400°C. The catalysts were used for oxidation of a mixture of CO and CH 4 (1:1). The catalysts were characterized by X-ray diffractometer, Brunauer-Emmett-Teller surface-area, X-ray photoelectron spectroscopy; temperature programmed reduction and Scanning electron microscopy coupled with Energy-Dispersive X-Ray Spectroscopy. The Na 2 CO 3 was adjudged as the best precipitant for production of catalyst, which completely oxidized CO-CH 4 mixture at the lowest temperature (T 100 =350°C). Whereas, for catalyst prepared using urea, T 100 =362°C. On the other hand the conversion of CO-CH 4 mixture over the catalyst synthesized by KOH limited to 97% even beyond 400°C. Further, the effect of higher calcination temperatures of 500 and 600°C was examined for the best catalyst. The total oxidation of the mixture was attained at higher temperatures of 375 and 410°C over catalysts calcined at 500 and 600°C respectively. Thus, the best precipitant established was Na 2 CO 3 and the optimum calcination temperature of 400°C was found to synthesize the NiCo 2 O 4 catalyst for the best performance in CO-CH 4 oxidation. Copyright © 2017. Published by Elsevier B.V.

  1. ICPP calcined solids storage facility closure study. Volume II: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    This document contains Volume II of the Closure Study for the Idaho Chemical Processing Plant Calcined Solids Storage Facility. This volume contains draft information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the four options described in Volume I: (1) Risk-Based Clean Closure; NRC Class C fill, (2) Risk-Based Clean Closure; Clean fill, (3) Closure to landfill Standards; NRC Class C fill, and (4) Closure to Landfill Standards; Clean fill.

  2. ICPP calcined solids storage facility closure study. Volume II: Cost estimates, planning schedules, yearly cost flowcharts, and life-cycle cost estimates

    International Nuclear Information System (INIS)

    1998-02-01

    This document contains Volume II of the Closure Study for the Idaho Chemical Processing Plant Calcined Solids Storage Facility. This volume contains draft information on cost estimates, planning schedules, yearly cost flowcharts, and life-cycle costs for the four options described in Volume I: (1) Risk-Based Clean Closure; NRC Class C fill, (2) Risk-Based Clean Closure; Clean fill, (3) Closure to landfill Standards; NRC Class C fill, and (4) Closure to Landfill Standards; Clean fill

  3. Formation of Rosette-Shaped Cd(II) Thiolate Coordination Polymer in Aqueous Solution and Conversion to CdS by Calcination

    International Nuclear Information System (INIS)

    Han, Sung June; Lee, Myung Han; Jeon, Young Jin

    2010-01-01

    We have synthesized rosette-shaped Cd-MSA CPs by a reaction between Cd(II) ions and MSA in aqueous solution and calcined the obtained CPs to obtain CdS microstructures. Upon calcination, the morphology of the CPs does not undergo any significant change, but the particle diameter decreases by 74%. This indicates that our strategy can be used for the synthesis of CPs from other metal thiolates as well. We expect this strategy to be suitable for the preparation of important metal chalcogenide nanostructures and microstructures that can be used in future applications. Coordination polymers (CPs) have attracted considerable attention because of their potential applications in gas storage, catalysis, ion exchange, separation, biomedicine, etc. For use in the above mentioned applications, the structure and morphology of these CPs have been controlled by judicious choice of metals, ligands, and reaction conditions. Recently, Oh and coworkers have reported that CPs can be successfully converted into metal oxides by calcination without causing any significant change in their morphology

  4. Electrochemical performance of LiV3O8 micro-rod at various calcination temperatures as cathode materials for lithium ion batteries

    Science.gov (United States)

    Noerochim, Lukman; Ginanjar, Edith Setia; Susanti, Diah; Prihandoko, Bambang

    2018-04-01

    Lithium vanadium oxide (LiV3O8) has been successfully synthesized by hydrothermal method followed by calcination via the reaction of Lithium hydroxide (LiOH) and ammonium metavanade (NH4VO3). The precursors were heated at hydrothermal at 200 °C and then calcined at different calcination temperature in 400, 450, and 500 °C. The characterization by X-ray diffraction (XRD) and scanning electron microscope (SEM) is indicated that LiV3O8 micro-rod have been obtained by this method. The cyclic voltammetry (CV) result showed that redox reaction occur in potential range between 2.42 - 3.57 V for the reduction reaction and oxidation reaction in potential range between 2.01 V-3.69 V. The highest result was obtained for sample 450 °C with specific discharge capacity of 138 mA/g. The result showed that LiV3O8 has a promising candidate as a cathode material for lithium ion batteries.

  5. Treatment of Oily Wastewater by the Optimization of Fe2O3 Calcination Temperatures in Innovative Bio-Electron-Fenton Microbial Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jung-Chen Wu

    2018-03-01

    Full Text Available Due to the fact that Iron oxide (Fe2O3 is known to have a good effect on the photochemical reaction of catalysts, an investigation in this study into the enhancement of the degradation performance of bio-electro-Fenton microbial fuel cells (Bio-E-Fenton MFCs was carried out using three photocatalytic cathodes. These cathodes were produced at different calcination temperatures of Fe2O3 ranging from 500 °C to 900 °C for realizing their performance as photo catalysts within the cathodic chamber of an MFC, and they were compared for their ability to degrade oily wastewater. Results show that a suitable temperature for the calcination of iron oxide would have a significantly positive effect on the performance of Bio-E-Fenton MFCs. An optimal calcination temperature of 500 °C for Fe2O3 in the electrode material of the cathode was observed to produce a maximum power density of 52.5 mW/m2 and a chemical oxygen demand (COD degradation rate of oily wastewater (catholyte of 99.3% within one hour of operation. These novel findings will be useful for the improvement of the performance and applications of Bio-E-Fenton MFCs and their future applications in the field of wastewater treatment.

  6. Effect of calcination temperature on the photocatalytic activity of TiO2 powders prepared by co-precipitation of TiCl3

    International Nuclear Information System (INIS)

    Yudoyono, Gatut; Ichzan, Nur; Zharvan, Vicran; Daniyati, Rizqa; Santoso, Hadi; Indarto, Bachtera; Pramono, Yono Hadi; Zainuri, Mochamad; Darminto

    2016-01-01

    The adsorption of basic dye methylene blue (MB) onto titanium dioxide (titania) powder that were prepared by coprecipitation method of TiCl 3 and NH 4 OH as iniatial material with different calcination temperature was studied to examine the photocatalytic activity. Synthesis process carried out by the solution pH was adjusted to be 8. Effect of calcination temperature on the titania powder were characterized with Differential Scanning Calorimetry/Thermogravimetry (DSC/TG), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). The result of TG and XRD showed that the NH 4 Cl decomposed between 235-372°C. The XRD result showed that the anatase TiO 2 only contained a single phase when the calcination temperature of the precursor at 800°C, and over which it began to grow rutile phase. The influence of synthesis condition on the photocatalytic activity of TiO 2 powder was determined by the photodegradation of MB dye under UV light.

  7. Effect of calcination temperature on the crystallite growth of cerium oxide nano-powders prepared by the co-precipitation process

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jian-Chih [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Chen, Wen-Cheng [School of Dentistry, College of Dental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan (China); Tien, Yin-Chun [Department of Orthopaedics, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan (China); Shih, Chi-Jen, E-mail: cjshih@kmu.edu.t [Department of Fragrance and Cosmetics Science, Kaohsiung Medical University, 100 Shi-Chuan1st Road, Kaohsiung 80708, Taiwan (China)

    2010-04-30

    Cerium oxide nanocrystallites were synthesized by a co-precipitation process at a relatively low temperature, using cerium (III) nitrate as the starting material in a water solution with pH in the range of 8-9. The effect of calcination temperature on the crystallite growth of cerium oxide nano-powders was investigated by X-ray diffraction, transmission electron microscopy and electron diffraction. The crystallization temperature of the cerium oxide powders was estimated to be about 273 K, by XRD analysis. When calcined at temperatures from 473 to 1273 K, face-centered cubic phase crystallization was observed by XRD. The crystallite size of the cerium oxide increased from 12.0 to 48 nm as the calcining temperature increased from 473 to 1273 K, in the pH range 8-9. The activation energy for the growth of cerium oxide nanoparticles was found to have very low values of 17.5 kJ/mol for pH = 8 and 16.0 kJ/mol for pH = 9.

  8. Competitive adsorption characteristics of fluoride and phosphate on calcined Mg-Al-CO{sub 3} layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Peng [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Zheng, Hong, E-mail: zhengh@cugb.edu.cn [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Wang, Chong; Ma, Hongwen; Hu, Jianchao; Pu, Yubing; Liang, Peng [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer The influences of pH, contact time and order of addition of the anions were obtained. Black-Right-Pointing-Pointer The kinetic data were found to fit very well the pseudo second-order kinetic model. Black-Right-Pointing-Pointer Data of equilibrium experiments were fitted well to Langmuir isotherm. Black-Right-Pointing-Pointer The competitive monolayer adsorption capacities obviously decreased. Black-Right-Pointing-Pointer ATR-FTIR proofs of competitive adsorption were obtained. - Abstract: With synthetic wastewater, competitive adsorption characteristics of fluoride and phosphate on calcined Mg-Al-CO{sub 3} layered double hydroxides (CLDH) were investigated. A series of batch experiments were performed to study the influence of various experimental parameters, such as pH, contact time, and order of addition of the anions on the competitive adsorption of fluoride and phosphate on CLDH. It was found that the optimal pH is around 6 and it took 24 h to attain equilibrium when fluoride and phosphate were simultaneous added. The order of addition of anions influenced the adsorption of fluoride and phosphate on CLDH. The kinetic data were analyzed using the pseudo first-order and pseudo second-order models and they were found to fit very well the pseudo second-order kinetic model. Data of equilibrium experiments were fitted well to Langmuir isotherm and the competitive monolayer adsorption capacities of fluoride and phosphate were found to be obviously lower than those of single anion at 25 Degree-Sign C. The results of X-ray diffraction, Scanning Electron Microscopy with energy-dispersive X-ray analyses, and ATR-FTIR demonstrate that the adsorption mechanism involves the rehydration of mixed metal oxides and concomitant intercalation of fluoride and phosphate ions into the interlayer to reconstruct the initial LDHs structure.

  9. Thermal and mechanical properties of NaOH treated hemp fabric and calcined nanoclay-reinforced cement nanocomposites

    International Nuclear Information System (INIS)

    Hakamy, A.; Shaikh, F.U.A.; Low, I.M.

    2015-01-01

    Highlights: • Fabrication of nanoclay and hemp fabric-reinforced cement composites. • The optimum nanoclay and hemp fabric content is 1.0 and 6.9 wt.% respectively. • Surface-treated hemp fabric-reinforced cement composites demonstrated better mechanical properties. • Surface modification of hemp fabric was effective in improving the hemp fabric-cement matrix adhesion. - Abstract: Cement nanocomposites reinforced with hemp fabrics and calcined nanoclay (CNC) have been fabricated and investigated. CNC is prepared by heating nanoclay (Cloisite 30B) at 900 °C for 2 h. The influences of CNC dispersion on the mechanical properties and thermal properties of these composites have been characterized in terms of porosity, density, water absorption, flexural strength, fracture toughness, impact strength and thermal stability. The microstructure is investigated using Quantitative X-ray Diffraction Analysis (QXDA) and High Resolution Transmission Electron Microscopy (HRTEM). The effects of alkali (NaOH) treatment of hemp fabric on the mechanical properties of hemp fabric-reinforced cement composites with different fabric contents of 4.5, 5.7, 6.9 and 8.1 wt% are also investigated. Results show that the optimum hemp fabric content is 6.9 wt% (i.e. 6 fabric layers). Results also indicated that physical, mechanical and thermal properties were enhanced due to the addition of CNC into the cement matrix and the optimum content of CNC was 1 wt%. The treated hemp fabric-reinforced nanocomposites containing 1 wt% CNC exhibited the highest flexural strength, fracture toughness, impact strength and thermal stability by virtue of good fibre–matrix interface. This environmentally friendly nanocomposite can be used for various construction applications such as ceilings and roofs

  10. Impact of natural and calcined starfish (Asterina pectinifera) on the stabilization of Pb, Zn and As in contaminated agricultural soil.

    Science.gov (United States)

    Lim, Jung Eun; Sung, Jwa Kyung; Sarkar, Binoy; Wang, Hailong; Hashimoto, Yohey; Tsang, Daniel C W; Ok, Yong Sik

    2017-04-01

    Metal stabilization using soil amendments is an extensively applied, economically viable and environmentally friendly remediation technique. The stabilization of Pb, Zn and As in contaminated soils was evaluated using natural starfish (NSF) and calcined starfish (CSF) wastes at different application rates (0, 2.5, 5.0 and 10.0 wt%). An incubation study was conducted over 14 months, and the efficiency of stabilization for Pb, Zn and As in soil was evaluated by the toxicity characteristic leaching procedure (TCLP) test. The TCLP-extractable Pb was reduced by 76.3-100 and 91.2-100 % in soil treated with NSF and CSF, respectively. The TCLP-extractable Zn was also reduced by 89.8-100 and 93.2-100 % in soil treated with NSF and CSF, respectively. These reductions could be associated with the increased metal adsorption and the formation of insoluble metal precipitates due to increased soil pH following application of the amendments. However, the TCLP-extractable As was increased in the soil treated with NSF, possibly due to the competitive adsorption of phosphorous. In contrast, the TCLP-extractable As in the 10 % CSF treatment was not detectable because insoluble Ca-As compounds might be formed at high pH values. Thermodynamic modeling by visual MINTEQ predicted the formation of ettringite (Ca 6 Al 2 (SO 4 ) 3 (OH) 12 ·26H 2 O) and portlandite (Ca(OH) 2 ) in the 10 % CSF-treated soil, while SEM-EDS analysis confirmed the needle-like structure of ettringite in which Pb was incorporated and stabilized in the 10 % CSF treatment.

  11. Characterizing the correlation between dephosphorization and solution pH in a calcined water treatment plant sludge.

    Science.gov (United States)

    Zhou, Zhenming; Liu, Qidi; Li, Shuwen; Li, Fei; Zou, Jing; Liao, Xiaobin; Yuan, Baoling; Sun, Wenjie

    2018-04-26

    This study focused on characterizing the correlation between the dephosphorization process of calcined water treatment plant sludge (C-WTPS) and the solution initial pH in batch experiments. The specific aim was to illustrate the effect of different initial pH on the adsorption and desorption of phosphorous in C-WTPS. In addition, the effects of solution initial pH on the release of ammonia nitrogen and total organic carbon (TOC) from C-WTPS and the change of pH after adsorption were also investigated. The results demonstrated that the initial pH significantly influenced the adsorption of phosphorus on C-WTPS. When initial pH was increased from 3 to 10, the phosphorous absorption capacity reduced by 76.5%. Especially, when the initial pH reached to 11, the phosphorus adsorption capacity became a negative value, indicating that C-WTPS released phosphorus into the solution. The addition of C-WTPS to the solution had little impact on the initial pH of the solution. The absorbed phosphorous on C-WTPS was relatively stable in the pH range of 3 to 10. Nevertheless, when the solution pH was higher than 11, it can be easily released into the solution. Furthermore, by comparison with WTPS, C-WTPS released less ammonia nitrogen and TOC into the solution and adsorbed more phosphorus from the solution in the experimental pH range. Therefore, C-WTPS is more suitable to serve as a cost-effective sorbent for phosphorus removal.

  12. Role of Mg{sub x}Ca{sub 1−x}CO{sub 3} on the physical–chemical properties and cyclic CO{sub 2} capture performance of dolomite by two-step calcination

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ke; Han, Dongtai, E-mail: handongtai@cumt.edu.cn; Zhao, Pengfei, E-mail: zhaopfcumt@163.com; Hu, Xiumeng; Yin, Zeguang; Wu, Di

    2015-08-20

    Highlights: • Two-step calcination treated dolomite sorbent was prepared and characterized. • An intermediate phase (Mg{sub x}Ca{sub 1−x}CO{sub 3}) was observed by TG and XRD results. • Mg-calcite hindered the de-mixing of Ca and Mg. • Smaller grains, larger specific surface area and pore volume were obtained. • This favorable structure resulted in a high and stable CO{sub 2} capture performance. - Abstract: Two-step calcination (CO{sub 2} and N{sub 2} atmospheres) was used to modify the microstructure of natural dolomite for high-temperature CO{sub 2} capture. Two other one-step calcinations (CO{sub 2} or N{sub 2} atmosphere) were provided for comparison. Different morphological characterizations (thermal decomposition, phase composition, morphology, and nitrogen adsorption) were performed, followed by an analysis of 30 carbonation/calcination cycles in a fixed bed reactor. During primary calcination in a CO{sub 2} atmosphere, an intermediate phase (Mg{sub x}Ca{sub 1−x}CO{sub 3}) was observed by TG and XRD results, which hindered the de-mixing of CaO and MgO in the secondary calcination in a N{sub 2} atmosphere. Therefore, two-step calcination produced smaller grains (CaO: 45.2 nm; MgO: 32.6 nm), larger specific surface area (21.08 m{sup 2}/g) and pore volume (0.082 cm{sup 3}/g) and uniform distribution of CaO and MgO, which resulted in a higher and more stable uptake of CO{sub 2} compared to the results from one-step calcinations.

  13. Influence of calcination temperature on Cd{sub 0.3}Co{sub 0.7}Fe{sub 2}O{sub 4} nanoparticles: Structural, thermal and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Ch.Venkata, E-mail: cvrphy@gmail.com [School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do 712-749 (Korea, Republic of); PrabhakarVattikuti, S.V. [School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do 712-749 (Korea, Republic of); Ravikumar, R.V.S.S.N. [Department of Physics, Acharya Nagarjuna University, AP 522510 (India); Moon, Sang Jun, E-mail: nanobiomems@dgist.ac.kr [Cybernetics Laboratory, Daegu Gyeongbuk Institute of Science and Technology (DGIST) (Korea, Republic of); Shim, Jaesool, E-mail: jshim@ynu.ac.kr [School of Mechanical Engineering, Yeungnam University, 214-1, Dae-dong, Gyeongsan-si, Gyeongsangbuk-do 712-749 (Korea, Republic of)

    2015-11-15

    Cadmium substituted cobalt ferrite nanoparticles are synthesis using the chemical method. The as-prepared ferrite nanoparticles are calcinated at 300 °C and 600 °C respectively. The samples are studied using; Powder XRD, SEM with EDX, TEM, FT-IR, TG-DTA and vibrating sample magnetometer (VSM) in order to study the calcination temperature effect on structural, morphological and magnetic properties. The magnetic properties, like saturation magnetization and coercivity increases with increasing the calcination temperature. This enhancement is attributed to the transition from amulti-domain to a single-domain nature. The absorption bands observed at 588 cm{sup −1} (ν{sub 1}) and 440 cm{sup −1} (ν{sub 2}) are attributed to the vibrations of tetrahedral and octahedral complexes. The TG-DTA curves reveal the thermal stability of the prepared ferrite nanoparticles. The calcination temperature influences the magnetic properties, surface morphology and crystalline size. - Highlights: • Cd{sub 0.3}Co{sub 0.7}Fe{sub 2}O{sub 4} nanoparticles synthesized using the chemical co-precipitation. • The magnetization, coercivity values increases with increasing the calcination temperature. • The calcination temperature influences the magnetic properties and crystallite size. • The FTIR spectra results confirmed the vibrations of tetrahedral and octahedral complexes.

  14. Rheology and zeta potential of cement pastes containing calcined silt and ground granulated blast-furnace slag

    Directory of Open Access Journals (Sweden)

    Safi, B.

    2011-09-01

    Full Text Available This study aimed to analyse the re-use of dam silt as a supplementary binder for self-compacting concrete (SCC. When burnt, silt becomes more reactive because the kaolin it contains is converted into metakaolin. Portland cement, calcined or burnt silt and ground granulated blast furnace slag were used in this research. Cement pastes were prepared with blends containing two or three of these materials. The replacement ratio for burnt silt in both cases was 10 % and 20 % by cement weight and the ratio for the slag was a constant 30 % by weight of the blend. Rheological and zeta potential tests were conducted to evaluate paste electrokinetics and rheological behaviour. The findings showed that burnt silt is apt for use as an addition to cement for SCC manufacture.

    En el presente trabajo se ha analizado la posibilidad de utilizar los lodos procedentes de embalses como adición en la fabricación del hormigón autocompactante (HAC. Con la calcinación, estos materiales se vuelven más reactivos debido a la transformación en metacaolín, del caolín que forma parte de su composición. Las materias primas empleadas en esta investigación son: cemento Pórtland, lodos de embalse calcinados y escorias granuladas de horno alto. Se prepararon pastas de cemento con mezclas que contenían dos o tres de estos materiales. El porcentaje de reemplazo de los lodos calcinados osciló entre el 10 y el 20 % en peso del cemento, mientras que el de la escoria fue del 30 % en peso de la mezcla. Se llevaron a cabo ensayos reológicos y de potencial zeta para evaluar el comportamiento electrocinético y reológico de las distintas pastas. De acuerdo con los resultados obtenidos, una vez calcinados, los lodos de embalse son aprovechables como adición al cemento con destino a la preparación de HAC.

  15. Effect of metal ratio and calcination temperature of chromium based mixed oxides catalyst on FAME density from palm fatty acid distillate

    Science.gov (United States)

    Wan, Z.; Fatimah, S.; Shahar, S.; Noor, A. C.

    2017-09-01

    Mixed oxides chromium based catalysts were synthesized via sol-gel method for the esterification of palm fatty acid distillate (PFAD) to produce fatty acid methyl ester (FAME). The reactions were conducted in a batch reactor at reaction temperature of 160 °C for 4 h and methanol to PFAD molar ratio of 3:1. The effects of catalyst preparation conditions which are the mixed metal ratio and calcination temperature were studied. The various metal ratio of Cr:Mn (1:0, 0:1, 1:1, 1:2 and 2:1) and Cr:Ti (0:1, 1:1, 1:2 and 2:1) resulted in FAME density ranges from 1.041 g/cm3 to 0.853 g/cm3 and 1.107 g/cm3 to 0.836 g/cm3, respectively. The best condition catalyst was found to be Cr:Ti metal ratio of 1:2 and Cr:Mn metal ratio of 1:1. The calcination temperature of the mixed oxides between 300 °C to 700°C shows effect on the FAME density obtained in the reaction. The calcination at 500°C gave the lowest FAME density of 0.836 g/cm3 and 0.853 g/cm3 for Cr:Ti and Cr:Mn mixed oxides, respectively. The density of FAME is within the value range of the biodiesel fuel property. Thus, mixed oxides of Cr-Ti and Cr-Mn have good potentials as heterogeneous catalyst for FAME synthesis from high acid value oils such as PFAD.

  16. Facile synthesis of both needle-like and spherical hydroxyapatite nanoparticles: effect of synthetic temperature and calcination on morphology, crystallite size and crystallinity.

    Science.gov (United States)

    Wijesinghe, W P S L; Mantilaka, M M M G P G; Premalal, E V A; Herath, H M T U; Mahalingam, S; Edirisinghe, M; Rajapakse, R P V J; Rajapakse, R M G

    2014-09-01

    Synthetic hydroxyapatite (HA) nanoparticles, that mimic natural HA, are widely used as biocompatible coatings on prostheses to repair and substitute human bones. In this study, HA nanoparticles are prepared by precipitating them from a precursor solution containing calcium sucrate and ammonium dihydrogen orthophosphate, at a Ca/P mole ratio of 1.67:1, at temperatures, ranging from 10°C to 95°C. A set of products, prepared at different temperatures, is analyzed for their crystallinity, crystallite size, morphology, thermal stability and composition, by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopic techniques, while the other set is analyzed after calcining the respective products, soon after their synthesis, for 3h, at 700°C. The as-prepared products, after 2h of drying, without any calcination, are not crystalline, but they grow very slowly into needle-like morphologies, as they are ripened with time. The percentage crystallinity of the final products increases from 15% to 52%, with increasing the preparative temperature. The calcined samples always produce spherical nanoparticles of essentially the same diameter, between 90 nm and 100 nm, which does not change due to aging and preparative temperatures. Therefore, the same method can be utilized to synthesize both spherical and needle-like nanoparticles of hydroxyapatite, with well-defined sizes and shapes. The ability to use readily available cheap raw materials, for the synthesis of such well-defined crystallites of hydroxyapatite, is an added advantage of this method, which may be explored further for the scaling up of the procedures to suit to industrial scale synthesis of such hydroxyapatite nanoparticles. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Oxidative desulfurization of benzothiophene and thiophene with WO{sub x}/ZrO{sub 2} catalysts: Effect of calcination temperature of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Zubair; Jeon, Jaewoo [Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Jhung, Sung Hwa, E-mail: sung@knu.ac.kr [Department of Chemistry and Green-Nano Materials Research Center, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer Oxidative desulfurization was studied with WO{sub x}/ZrO{sub 2} calcined at different temp. Black-Right-Pointing-Pointer The importance of the phases of zirconia and tungsten oxide was suggested. Black-Right-Pointing-Pointer The catalyst was analyzed thoroughly with Raman and XRD techniques. Black-Right-Pointing-Pointer The importance of electron density on S was confirmed with the kinetics of oxidation. - Abstract: Oxidative desulfurization (ODS) of model fuel containing benzothiophene (BT) or thiophene (Th) has been carried out with WO{sub x}/ZrO{sub 2} catalyst, which was calcined at various temperatures. Based on the conversion of BT in the model fuel, it can be shown that the optimum calcination temperature of WO{sub x}/ZrO{sub 2} catalyst is around 700 Degree-Sign C. The most active catalyst is composed of tetragonal zirconia (ZrO{sub 2}) with well dispersed polyoxotungstate species and it is necessary to minimize the contents of the crystalline WO{sub 3} and monoclinic ZrO{sub 2} for a high BT conversion. The oxidation rate was interpreted with the first-order kinetics, and it demonstrated the importance of electron density since the kinetic constant for BT was higher than that for Th even though the BT is larger than Th in size. A WO{sub x}/ZrO{sub 2} catalyst, treated suitably, can be used as a reusable active catalyst in the ODS.

  18. The Influence of Using Fe2O3 Additive Materials of the Calcine Coke's Pellet to Physical Characteristic Product Graphitization at the Temperature 1500 oC

    International Nuclear Information System (INIS)

    Kasilani NS; Tunjung I; Triyono

    2002-01-01

    The pellet's consisted of two size particles calcine coke's are 2 O 3 (0.5%; 0.75% and 1% from total weight) and tar pith, heated, to shaped and pressed into 27 KN. Pellet's baked at 1500 o C temperature with variated time, were tried to characteristic of the resistivity, the density and the hardness. The heated to changed the demention, phases and deformation. At the 1% additive material's of 2-1 code's and 60 minutes roasted, are reached the resistivity 0.597 Ω-cm, the densities 1.182 g/ml, the hardness 17.6 kg/mm 2 . (author)

  19. The Synergistic Effect of Nitrogen Dopant and Calcination Temperature on the Visible-Light-Induced Photoactivity of N-Doped TiO2

    Directory of Open Access Journals (Sweden)

    Yao-Tung Lin

    2013-01-01

    Full Text Available The synergistic effect of nitrogen content and calcinations temperature on the N-doped TiO2 catalysts prepared by sol-gel method was investigated. The phase and structure, chemical state, optical properties, and surface area/pore distribution of N-doped TiO2 were characterized using X-ray diffraction spectrometer, high-resolution transmission electron microscope, X-ray photoelectron spectroscopy, UV-vis diffusion reflectance spectroscopy, and Brunauer-Emmett-Teller specific surface area. Finding showed that the photocatalytic activity of N-doped TiO2 was greatly enhanced compared to pure TiO2 under visible irradiation. N dopants could retard the transformation from anatase to rutile phase. Namely, N-doping effect is attributed to the anatase phase stabilization. The results showed nitrogen atoms were incorporated into the interstitial positions of the TiO2 lattice. Ethylene was used to evaluate the photocatalytic activity of samples under visible-light illumination. The results suggested good anatase crystallization, smaller particle size, and larger surface are beneficial for photocatalytic activity of N-doped TiO2. The N-doped TiO2 catalyst prepared with ammonia to titanium isopropoxide molar ratio of 2.0 and calcinated at 400°C showed the best photocatalytic ability.

  20. Synthesis-microstructure-performance relationship of layered transition metal oxides as cathode for rechargeable sodium batteries prepared by high-temperature calcination.

    Science.gov (United States)

    Xie, Man; Luo, Rui; Lu, Jun; Chen, Renjie; Wu, Feng; Wang, Xiaoming; Zhan, Chun; Wu, Huiming; Albishri, Hassan M; Al-Bogami, Abdullah S; El-Hady, Deia Abd; Amine, Khalil

    2014-10-08

    Research on sodium batteries has made a comeback because of concern regarding the limited resources and cost of lithium for Li-ion batteries. From the standpoint of electrochemistry and economics, Mn- or Fe-based layered transition metal oxides should be the most suitable cathode candidates for affordable sodium batteries. Herein, this paper reports a novel cathode material, layered Na1+x(Fey/2Niy/2Mn1-y)1-xO2 (x = 0.1-0.5), synthesized through a facile coprecipitation process combined with subsequent calcination. For such cathode material calcined at 800 °C for 20 h, the Na/Na1+x(Fey/2Niy/2Mn1-y)1-xO2 (x = 0.4) electrode exhibited a good capacity of 99.1 mAh g(-1) (cycled at 1.5-4.0 V) and capacity retention over 87% after 50 cycles. Optimization of this material would make layered transition metal oxides a strong candidate for the Na-ion battery cathode.

  1. Transesterification of edible, non-edible and used cooking oils for biodiesel production using calcined layered double hydroxides as reusable base catalysts.

    Science.gov (United States)

    Sankaranarayanan, Sivashunmugam; Antonyraj, Churchil A; Kannan, S

    2012-04-01

    Fatty acid methyl esters (FAME) were produced from edible, non-edible and used cooking oils with different fatty acid contents by transesterification with methanol using calcined layered double hydroxides (LDHs) as solid base catalysts. Among the catalysts, calcined CaAl2-LDH (hydrocalumite) showed the highest activity with >90% yield of FAME using low methanol:oil molar ratio (<6:1) at 65 °C in 5 h. The activity of the catalyst was attributed to its high basicity as supported by Hammett studies and CO(2)-TPD measurements. The catalyst was successfully reused in up to four cycles. Some of the properties such as density, viscosity, neutralization number and glycerol content of the obtained biodiesel matched well with the standard DIN values. It is concluded that a scalable heterogeneously catalyzed process for production of biodiesel in high yields from a wide variety of triglyceride oils including used oils is possible using optimized conditions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Morphological Changes of Limestone Sorbent Particles during Carbonation/Calcination Looping Cycles in a Thermogravimetric Analyzer (TGA) and Reactivation with Steam

    KAUST Repository

    Wu, Y.

    2010-04-15

    Carbonation and calcination looping cycles were carried out on four limestones in a thermogravimetric analyzer (TGA). The CO2 carrying capacity of a limestone particle decays very quickly in the first 10 cycles, reducing to about 20% of its original uptake capacity after 10 cycles for the four limestones studied in this work, and it decreases further to 6-12% after 50 cycles. A new steam reactivation method was applied on the spent sorbent to recover the loss of reactivity. The steam reactivation of multi-cycled samples was conducted at atmospheric pressure. Steam reactivation for 5 min at 130 °C of particles that had undergone 10 cycles resulted in an immediate increase (by 45-60% points) in carrying capacity. The morphological changes of limestone particles during the cycling and steam reactivation were studied using both an optical microscope and scanning electron microscopy (SEM). The diameters of limestone particles shrank by about 2-7% after 10 carbonation/calcination cycles, and the particle diameters swelled significantly (12-22% increase) after steam reactivation. These size changes are important for studies of attrition and mathematical modeling of carbonation. © 2010 American Chemical Society.

  3. Effect of the heat curing on strength development of self-compacting mortars containing calcined silt of dams and Ground Brick Waste

    Directory of Open Access Journals (Sweden)

    B. Safi

    2013-01-01

    Full Text Available The strength development of self-compacting mortars (SCM containing calcined silt (CS and ground brick waste (GWB was investigated. The variables are the nature of addition (CS and GWB in the binder and the heat curing at different temperatures (20 ºC and 60 ºC at 7 and 14 days of curing. Two temperatures 20 and 60 ºC were applied to samples with intermediate levels (depending on the drying method applied to precast for 18 hours in total. In this study, a Portland cement (CEMII, Calcined silt (750 ºC for 5 hours, ground waste brick, were used in the binders of SCM. The results show that the compressive strength to 14 days of mortars, increases with annealing (60 ºC compared to that measured at 20 ºC. Also, values of compressive strength of mortars at 14 days that are close to those obtained without 28 days curing treatment. Indeed, a strength gain of about 20.5% and 27.3% was obtained respectively for the SCM with GWB and the SCM with CS. However, a small change in mass recorded for both types of mortars.

  4. Investigation of the possibility of copper removal from industrial leachate by raw and calcined phosphogypsum: D-optimal and Taguchi designs

    International Nuclear Information System (INIS)

    Mesci, Basak; Turan, Nurdan Gamze; Ozgonenel, Okan

    2012-01-01

    In the present study, the removal of Cu(II) was evaluated by raw and calcined phosphogypsum (PG) as an industrial product. The role of experimental factors on the removal of Cu(II) was examined by using D-optimal and Taguchi designs. The experimental factors and their related levels were selected as initial pH of 3-6-8, adsorbent content of 5, 10, and 25 g L -1 , contact time of 5, 10, and 20 min, and temperature of 20, 40, and 60 C. The results are evaluated by ANOVA test to extract important experimental factors and their levels. The performances of the suggested factorial designs were then compared and regression models that took into account the significant main and interaction effects were suggested. Taguchi design was found as a reliable solution with less number of experiments for adsorption studies with the optimized values. The resultant removal efficiency is calculated as 78.34%. The results revealed that calcined PG is an appropriate adsorbent for Cu(II) removal from leachate of industrial waste. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Study the effect of calcination temperature on physical and magnetic properties of bare Cobalt nanoparticles and that coated with silica shell

    International Nuclear Information System (INIS)

    Arabi, H.; Pourarian, F.; Chahkandinejad, R.

    2012-01-01

    In this paper, in order to investigate the effect of calcination temperature on the structural and magnetic properties of cobalt nanoparticles, samples have been prepared by Co-precipitation method at different calcination temperature. Cobalt nanoparticles have been prepared by Co-precipitation method at room temperature using hydrazine as reducing in ethanol hydrazine alkaline environment. This agent reduces cobalt salts to Cobalt nanoparticles in FCC and HCP phases. Phase analysis and investigation of Structural properties of the samples using X-ray diffraction patterns (XRD) confirm the formation of hexagonal phases of Co nanoparticles. Transmission electron microscopy was used for determining the size and shape morphology of nanoparticles. Magnetic properties of these nanoparticles have been investigated using a Vibrating sample magnetometer. The results indicate that these nanoparticles are ferromagnetic at room temperature. In addition, in this paper Co nanoparticles coated with silica shell have been prepared by the wet chemical method. Transmission electron microscopy images showed the cobalt core with average diameter of 17-20 nm coated by a silica shell with thickness of 5-7 nm. Hysteresis Loop of these Co nanoparticles coated by silica shell illustrates 16.9 emu/gr for saturation magnetization at 10000 (Oe), which is much less than that of Cobalt nanoparticles

  6. Brandon mathematical model describing the effect of calcination and reduction parameters on specific surface area of UO{sub 2} powders

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Nguyen Trong; Thuan, Le Ba [Institute for Technology of Radioactive and Rare Elements (ITRRE), 48 Lang Ha, Dong Da, Ha Noi (Viet Nam); Van Khoai, Do [Micro-Emission Ltd., 1-1 Asahidai, Nomi, Ishikawa, 923-1211 (Japan); Lee, Jin-Young, E-mail: jinlee@kigam.re.kr [Convergence Research Center for Development of Mineral Resources (DMR), Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 305-350 (Korea, Republic of); Jyothi, Rajesh Kumar, E-mail: rkumarphd@kigam.re.kr [Convergence Research Center for Development of Mineral Resources (DMR), Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon, 305-350 (Korea, Republic of)

    2016-06-15

    Uranium dioxide (UO{sub 2}) powder has been widely used to prepare fuel pellets for commercial light water nuclear reactors. Among typical characteristics of the powder, specific surface area (SSA) is one of the most important parameter that determines the sintering ability of UO{sub 2} powder. This paper built up a mathematical model describing the effect of the fabrication parameters on SSA of UO{sub 2} powders. To the best of our knowledge, the Brandon model is used for the first time to describe the relationship between the essential fabrication parameters [reduction temperature (T{sub R}), calcination temperature (T{sub C}), calcination time (t{sub C}) and reduction time (t{sub R})] and SSA of the obtained UO{sub 2} powder product. The proposed model was tested with Wilcoxon's rank sum test, showing a good agreement with the experimental parameters. The proposed model can be used to predict and control the SSA of UO{sub 2} powder.

  7. The influence of calcination temperatures on the acid-based properties and catalytic activity for the 1,3-butadiene synthesis from ethanol/acetaldehyde mixture

    Science.gov (United States)

    Gao, Meixiang; Jiang, Haoxi; Zhang, Minhua

    2018-05-01

    The influences of the calcination temperature on the catalysts' acid-based properties and catalytic activity for the 1,3-butadiene synthesis from ethanol are investigated. The results show that the 2 wt% ZrO2/Nano-SiO2 calcined at 773 K shows the best performance with the selectivity of 93.18% and conversion of 58.52% when reacted at 593 K, a WHSV of 1.8 h-1 and 3.5:1 volume ratio ethanol-to-acetaldehyde in an atmospheric fixed-bed reactor. Prepared catalysts were characterized by N2 adsorption-desorption, XRD, temperature-programmed desorption of NH3 and CO2, FTIR spectroscopy of adsorbed pyridine and CO2. Based on the relationship between the catalyst activity and its properties, the fact can be presumed that the formation and strength of Zrsbnd Osbnd Si bond determines the acid-based properties of the catalyst. In addition, moderate-intensity weak acid-basic sites are more suitable for ethanol conversion to BD with the amount of acid and basic sites as close as possible.

  8. To study the effect of calcinations durations and temperature on optical and structural properties of MgO-CuO nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Rajesh, E-mail: rkkaushik06@gmail.com [Deptt. of Physics, M.D. University, Rohtak-124001, Haryana (India); Deptt. of Physics,Vaish College of Engineering, Rohtak-124001, Haryana (India); Praveen,; Sharma, Ashwani; Parmar, R.; Dahiya, S. [Deptt. of Physics, M.D. University, Rohtak-124001, Haryana (India); Kishor, N. [Deptt. of Physics, Central University of Haryana (India)

    2016-05-06

    The MgO-CuO nanocomposites has been synthesized by a sol-gel techniques based on precursor polyvinyl alcohol (PVA). In this work appropriate concentration of cupric nitrate, Magnisium nitrate and PVA are mixed with 50:50 ethanol water followed by heated to 80°C to form a homogeneous gel solution. The obtained gel was slowly heated at 100°C to evaporate the solvent to form a hard homogeneous gel. The hard gel was calcinated at temperature 600°C for 4 hrs and 6 hrs thereafter, crushed the material in agate-motar so that it is converted into fine powder form. The prepared nanocomposites have been characterized using X-Ray Diffraction (XRD), FTIR, UV-VIS spectroscopy, SEM etc. The size of MgO-CuO nanocomposites heated at 600°C for 4 hours and 6 hours evaluated by Debye Scherrer formula are 17.1 nm and 21.2 nm respectively and results show that Size of MgO-CuO nanocomposites increases with increase of calcinations durations. IR spectra is also used to determine purity of samples. Absorption spectra confirm the synthesis of nanomaterials. SEM images give the indication of morphology of the nanocomposites.

  9. Particle morphology and magnetic properties of Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19} powder calcined conventionally and by microwave heating

    Energy Technology Data Exchange (ETDEWEB)

    Kanagesan, S., E-mail: kanagu1980@gmail.com [Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia); Hashim, M. [Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia); Physics Department, Faculty of Science, Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia); Jesurani, S. [Department of Physics, Jeyaraj Annapackium College for Women, Periyakulam 625601, Tamil Nadu (India); Kalaivani, T. [Center for material science and Nano Devices, Department of Physics, SRM University, Kattankulathur 603203, Tamil Nadu (India); Ismail, I.; Shafie, M.S.E. [Materials Synthesis and Characterization Laboratory (MSCL), Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, Serdang 43400, Selangor (Malaysia)

    2012-12-05

    Highlights: Black-Right-Pointing-Pointer Synthesis of Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19} by sol-gel technique. Black-Right-Pointing-Pointer Crystallization temperature is reduced to 900 Degree-Sign C due to the addition of D-Fructose. Black-Right-Pointing-Pointer Results of conventional and microwave calcined samples are reported. - Abstract: Barium strontium hexaferrite (Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19}-BSF) has been prepared by sol-gel process involving use of D-Fructose as a fuel. The prepared precursor was calcined in two different calcinations techniques conventional and microwave furnace. X-ray powder diffraction studies confirmed the formation of single phase Ba{sub 0.5}Sr{sub 0.5}Fe{sub 12}O{sub 19}. HR-SEM results show the morphology of the particles is hexagonal structures in platelet form. The average particle size of conventionally calcined BSF powder is 100-250 nm and that of microwave calcined powder is 30-100 nm. The broad hysteresis loop reveals that powder is well crystallized and exhibits hard magnetic properties.

  10. Influence of Zn/Fe Molar Ratio on Optical and Magnetic Properties of ZnO and ZnFe2O4 Nanocrystal as Calcined Products of Layered Double Hydroxides

    Directory of Open Access Journals (Sweden)

    Abdullah Ahmed Ali Ahmed

    2014-01-01

    Full Text Available The coprecipitation method has been used to synthesize layered double hydroxide (Zn-Fe-LDH nanostructure at different Zn2+/Fe3+ molar ratios. The structural properties of samples were studied using powder X-ray diffraction (PXRD. LDH samples were calcined at 600°C to produce mixed oxides (ZnO and ZnFe2O4. The crystallite size of mixed oxide was found in the nanometer scale (18.1 nm for ZnFe2O4 and 43.3 nm for ZnO. The photocatalytic activity of the calcination products was investigated using ultraviolet-visible-near infrared (UV-VIS-NIR diffuse reflectance spectroscopy. The magnetic properties of calcined LDHs were investigated using a vibrating sample magnetometer (VSM. The calcined samples showed a paramagnetic behavior for all Zn2+/Fe3+ molar ratios. The effect of molar ratio on magnetic susceptibility of the calcined samples was also studied.

  11. Effects of calcining temperature on photocatalysis of g-C{sub 3}N{sub 4}/TiO{sub 2} composites for hydrogen evolution from water

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Ailan, E-mail: elainqal@163.com; Xu, Xinmei; Xie, Haolong; Zhang, Yangyu; Li, Yuyu; Wang, Junxian

    2016-08-15

    Highlights: • TiO{sub 2} promotes melon to form at 400 °C, whereas it forms at 500 °C for only melamine. • The highest photocatalytic activity was achieved when calcination was performed at 400 °C. • Coordinated N−Ti−N bonds were formed in MA/TiO{sub 2} (400) and disappeared at high temperature. • The surface area decreased and the pore size increased with increasing of temperature. • Only MA/TiO{sub 2} (400) has a narrower band gap than pure g-C{sub 3}N{sub 4}. - Abstract: A composite of graphitic carbon nitride and TiO{sub 2} (g-C{sub 3}N{sub 4}/TiO{sub 2}) with enhanced photocatalytic hydrogen evolution capacity was achieved by calcining melamine and TiO{sub 2} sol-gel precursor. Characterization results reveal that heating temperature had a great influence on the structure, surface area and properties of the composites. Compared with the polycondensation of pure melamine, the presence of TiO{sub 2} precursor can promote the formation of melon at a low temperature. The highest photocatalytic activity of g-C{sub 3}N{sub 4}/TiO{sub 2}(400) was achieved when the calcination was performed at 400 °C, exhibiting H{sub 2} production rate of 76.25 μmol/h under UV–vis light irradiation (λ > 320 nm) and 35.44 μmol/h under visible light irradiation (λ > 420 nm). The highest photocatalytic performance of g-C{sub 3}N{sub 4}/TiO{sub 2}(400) can be attributed to: (1) the strong UV–vis light absorption due to the narrow bandgap caused by synergic effect of TiO{sub 2} and g-C{sub 3}N{sub 4}, (2) high surface area and porosity, (3) the effective separation of photo-generated electron-holes owing to the favorable heterojunction between TiO{sub 2} and g-C{sub 3}N{sub 4}.

  12. Volatility of ruthenium-106, technetium-99, and iodine-129, and the evolution of nitrogen oxide compounds during the calcination of high-level, radioactive nitric acid waste

    International Nuclear Information System (INIS)

    Rimshaw, S.J.; Case, F.N.; Tompkins, J.A.

    1980-02-01

    The nitrate anion is the predominant constituent in all high-level nuclear wastes. Formic acid reacts with the nitrate anion to yield noncondensable, inert gases (N 2 or N 2 O), which can be scrubbed free of 106 Ru, 129 I, and 99 Tc radioactivities prior to elimination from the plant by passing through HEPA filters. Treatment of a high-level authentic radioactive waste with two moles of formic acid per mole of nitrate anion leads to a low RuO 4 volatility of about 0.1%, which can be reduced to an even lower level of 0.007% on adding a 15% excess of formic acid. Without pretreatment of the nitrate waste with formic acid, a high RuO 4 volatility of approx. 35% is observed on calcining a 4.0 N HNO 3 solution in quartz equipment at 350 0 C. The RuO 4 volatility falls to approx. 1.0% on decreasing the initial HNO 3 concentration to 1.0 N or lower. It is postulated that thermal denitration of a highly nitrated ruthenium complex leads to the formation of volatile RuO 4 , while decarboxylation of a ruthenium-formate complex leads to the formation of nonvolatile RuO 2 . Wet scrubbing with water is used to remove RuO 4 from the off-gas stream. In all glass equipment, small amounts of particulate RuO 2 are formed in the gas phase by decomposition of RuO 4 . The 99 Tc volatility was found to vary from 0.2 to 1.4% on calcining HNO 3 and HCOOH (formic acid) solutions over the temperature range of 250 to 600 0 C. These unexpectedly low volatilities of 99 Tc are correlated to the high thermal stability limits of various metal pertechnetates and technetates. Iodine volatilities were high, varying from a low of 30% at 350 0 C to a high of 97% at 650 0 C. It is concluded that with a proper selection of pretreatment and operating conditions the 106 Ru and 99 Tc activities can be retained in the calcined solid with recycle of the wet scrubbing solution

  13. Preparation of a sup(99m) Tc generator for use in nuclear medicine, using calcinated (10000C) alumina as an adsorber for 99Mo

    International Nuclear Information System (INIS)

    Gasiglia, H.T.; Enoshita, M.

    1980-12-01

    The preparation of 99 sup(m) Tc generator using calcinated (1000 0 C) alumina as adsorber for 99 Mo is described. The adsorption of 99 Mo and the elution of 99 sup(m) Tc were studied. When the generator is autoclaved (30 minutes, 121 0 C), after the loading of 99 Mo, elution yields of 99 sup(m) Tc fall to the half if compared whith generators not autoclaved. However, by autoclaving 99 Mo loading solution and alumina column separately and than preparing the generator, 80% elution yields of 99 sup(m) Tc were obtained. The contamination of the generator by microorganism is avoided when the loading of the 99 Mo is carried out in a hot-cell under UV ligth. The radioactive, radiochemical, chemical and microbiological purity criteria were examined for 99 sup(m) Tc solutions. The generator is considered safe for medical purposes. (Author) [pt

  14. Design and performance of a 100-kg/h, direct calcine-fed electric-melter system for nuclear-waste vitrification

    International Nuclear Information System (INIS)

    Dierks, R.D.

    1980-11-01

    This report describes the physical characteristics of a ceramic-lined, joule-heated glass melter that is directly connected to the discharge of a spray calciner and is currently being used to study the vitrification of simulated nuclear-waste slurries. Melter performance characteristics and subsequent design improvements are described. The melter contains 0.24 m 3 of glass with a glass surface area of 0.76 m 2 , and is heated by the flow of an alternating current (ranging from 600 to 1200 amps) between two Inconel-690 slab-type electrodes immersed in the glass at either end of the melter tank. The melter was maintained at operating temperature (900 to 1260 0 C) for 15 months, and produced 62,000 kg of glass. The maximum sustained operating period was 122 h, during which glass was produced at the rate of 70 kg/h

  15. Calcination and solid state reaction of ceramic-forming components to provide single-phase superconducting materials having fine particle size

    Science.gov (United States)

    Balachandran, Uthamalingam; Poeppel, Roger B.; Emerson, James E.; Johnson, Stanley A.

    1992-01-01

    An improved method for the preparation of single phase, fine grained ceramic materials from precursor powder mixtures where at least one of the components of the mixture is an alkali earth carbonate. The process consists of heating the precursor powders in a partial vacuum under flowing oxygen and under conditions where the partial pressure of CO.sub.2 evolved during the calcination is kept to a very low level relative to the oxygen. The process has been found particularly suitable for the preparation of high temperature copper oxide superconducting materials such as YBa.sub.2 Cu.sub.3 O.sub.x "123" and YBa.sub.2 Cu.sub.4 O.sub.8 "124".

  16. Water-n-BuOH solvothermal synthesis of ZnAl-LDHs with different morphologies and its calcined product in efficient dyes removal.

    Science.gov (United States)

    Huang, Gailing; Sun, Yingying; Zhao, Chencong; Zhao, Yifei; Song, Zhaoyuan; Chen, Junli; Ma, Shulan; Du, Junping; Yin, Zhigang

    2017-05-15

    In this study, water-n-BuOH mixed solvents were used to synthesize the ZnAl-layered double hydroxides (ZnAl-LDHs) via hydrothermal method. The XRD, FT-IR, SEM, ICP and CHN analyses revealed that the type of intercalated anions, the layer Zn/Al ratios, and morphologies of the LDHs depended on the ratio of V(water)/V(n-BuOH) in the mixed solvents. When the ratio of V(water)/V(n-BuOH) is 3 or 0.3, the as-prepared LDHs had 3D "silk flowers" (ZnAl-LDH-3) or "Sedimentary rock" morphology (ZnAl-LDH-0.3). Adsorption properties of dyes on calcined LDHs were studied. Compared with ZnAl-LDO-0.3 and ZnAl-LDO-w (calcined from the LDHs obtained in pure water), ZnAl-LDO-3 showed much better adsorption efficiency for anionic dyes thanks to its much larger BET-specific surface area. The sorption kinetics for dyes was appropriately described by the pseudo-second-order model and sorption isotherms can be fitted more satisfactorily by the Langmuir model. With the increasing concentrations of dyes from 10mg/L to 400mg/L, the maximum absorption capacities of ZnAl-LDO-3 were 1540mg/g (2.21mmol/g) for congo red, 1153mg/g (3.52mmol/g) for methyl orange and 390mg/g (0.63mmol/g) for active red (X-3B), respectively. The adsorption dyes onto the external surface is still the main mechanism for LDO adsorbents. The ZnAl-LDO-3 was a potential adsorbent for dyeing wastewater treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Fabrication and characterization of ZnO nanowires array electrodes with high photocurrent densities: Effects of the seed layer calcination time

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yi-Jing; Liu, Ching-Fang; Hu, Chi-Chang, E-mail: cchu@che.nthu.edu.tw; Kuo, Jen-Hou; Boddula, Rajender

    2017-03-01

    In this work, we demonstrate that vertically grown ZnO nanowire (NW) arrays of the wurzite phase were successfully fabricated on fluorine doped tin oxide (FTO) substrates via a hydrothermal method. The coating of a seed layer onto the FTO substrates was found to favor the growth of a uniform ZnO NWs array which shows saturation in the photocurrent density with a relatively low potential bias. Furthermore, prolonging the calcination time of the seed layer makes the ZnO NWs behave the better charge separation and improve the photo-electrochemical performance. Under the irradiation at a 75 mW cm{sup −2} from a simulated sunlight source, the ZnO NWs array electrode prepared from the seed layer with calcination at 350 °C for 5 h shows a saturated photocurrent density of 514 μA cm{sup −2} and a maximum half-cell solar-to-hydrogen (HC-STH) efficiency of 0.26% was obtained at 0.6 V versus reversible hydrogen electrode (RHE) in neutral electrolyte. - Highlights: • The seed layer annealing time strongly influences the textural and photo-activity of ZnO NWs. • The average diameter and density of ZnO NWs were controlled to 47–70 nm and 46–70 NWs μm{sup −2}, respectively. • ZnO NWs show promising application potential in solar-electrocatalytic water splitting under potential bias. • The ZnO NWs with SL annealing time = 5 h achieve the highest HC-STH efficiency of 0.26% at 0.6 V.

  18. Alizarin red S dye removal from contaminated water on calcined [Mg/Al, Zn/Al and MgZn/Al]-LDH

    Science.gov (United States)

    Aissat, Miloud; Hamouda, Sara; Benhadria, Naceur; Chellali, Rachid; Bettahar, Noureddine

    2018-05-01

    The waste water rejected by the textile industries is loaded with organic dyes, responsible for the high color present in the effluents. Some dyes and / or their degradation products could be carcinogenic and may have mutagenic properties. The rapid growth of the global economy has caused many environmental problems with a huge pollution problem. The abuse use of chemicals product is an environmental toxicological problem. The consequences can be serious for water resources. In this perspective, our study comes to participate with new means of depollution using new materials with interesting properties in the treatment of pollution. Among these materials, LDHs whose synthesis is easy and inexpensive can be a tool in the treatment of water Polluted [1]. Our contribution consists in using HDL as a means of sorption of dyes which are considered as polluting agents of waters especially for the industry textile. This study considers the removal of the Alizarine Red S (AR) from water on calcined MgAl,ZnAL and MgZnAL-layered double hydroxides. The different LDH was prepared by copreprecipation method. The materials was obtained for molar ratios R =2 for the different LDH. The carbonated layered Calcination of these solids leads to the formation of mixed oxides which have the property of being able to be regenerated by adsorbing new anionic entities. Adsorbents and adsorption products were characterized by physicochemical techniques. The structural characterization of the material was carried out by X-ray diffraction, infrared spectroscopy (FTIR). Dosages of the polluted solutions were monitored by UV-Visible spectrometry.

  19. MoO3/SiO2-ZrO2 Catalyst: Eeffect of Calcination Temperature on Physico-chemical Properties and Activities in Nitration of Toluene

    Directory of Open Access Journals (Sweden)

    Sunil Madhavrao Kemdeo

    2012-12-01

    Full Text Available 12 wt % molybdena was deposited over 1:1 silica zirconia mixed oxide support and the resultant catalyst was calcined between the 500 to 700 oC range of temperature. The samples were characterized by XRD, FT-IR, BET, SEM, NH3-TPD and pyridine adsorbed FT-IR techniques.  Nitration of toluene was studied as a model reaction over the prepared catalysts and parameters like effect of reaction temperature, effect of various solvents, catalyst reusability are studied. It was found that conversion of toluene varies with the presence of Brönsted acid sites over the catalyst surface and para-nitrotoulene selectivity is associated with pore size of the catalyst. Over the same catalysts, nitration was extended for some other aromatics. Avoid of sulfuric acid in the present process is an interesting concern in view of green chemistry. Copyright © 2012 by BCREC UNDIP. All rights reservedKeywords: MoO3/SiO2-ZrO2; SO2-ZrO2; NH3-TPD; Nitration; ortho-nitro tolueneReceived: 19th May 2012, Revised: 24th May 2012, Accepted: 26th May 2012[How to Cite: S.M. Kemdeo. (2012. MoO3/SiO2-ZrO2 Catalyst: Effect of Calcination Temperature on Physico-chemical Properties and Activities in Nitration of Toluene. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (2: 92-104. doi:10.9767/bcrec.7.2.3521.92-104] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3521.92-104 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/3521] | View in 

  20. Controlled synthesis of MoO3 microcrystals by subsequent calcination of hydrothermally grown pyrazine–MoO3 nanorod hybrids and their photodecomposition properties

    International Nuclear Information System (INIS)

    Rajagopal, S.; Nataraj, D.; Khyzhun, O.Y.; Djaoued, Yahia; Robichaud, Jacques; Kim, Chang-Koo

    2013-01-01

    We present our results on successful synthesis of pyrazine–MoO 3 nanorod hybrids by using pyrazine and MoO 3 nanorods. On the first stage, MoO 3 nanorods were grown hydrothermally and, on the second stage, their mixture with pyrazine was again involved in a hydrothermal reaction to produce organic–inorganic hybrids. To understand the growth mechanism of the hybrids we varied time and temperature of the hydrothermal process. Intercalation of pyrazine was confirmed through X-ray diffraction analysis, X-ray photoelectron spectroscopy, X-ray emission spectroscopy, scanning electron microscopy methods. Upon calcinations, pyrazine was deintercalated, i.e. removed from the MoO 3 hybrid system, and the MoO 3 nanorods were found to bind together resulting in formation of MoO 3 microslabs with increased surface area. Photodecomposition performance of the MoO 3 nanorods, pyrazine–MoO 3 hybrids and MoO 3 microcrystals was studied against Procion Red MX-5B textile dye. A high photodecomposition performance was found to decrease when going from MoO 3 nanorods to MoO 3 microcrystal and, further, to pyrazine–MoO 3 hybrids. - Graphical abstract: Display Omitted - Highlights: • High aspect ratio MoO 3 nanorods were prepared through a new hydrothermal method. • Hybrids of pyrazine–MoO 3 were formed by intercalating pyrazine into MoO 3 nanorods. • Intercalation of pyrazine was confirmed in X-ray spectroscopic analysis. • After calcinations, MoO 3 crystal was retained by binding MoO 3 nanorods together. • High photodegradation performance was noticed from MoO 3 nanorods

  1. Estudio de la adición de arcillas calcinadas en la durabilidad de hormigones Study of the addition of calcined clays in the durability of concrete

    Directory of Open Access Journals (Sweden)

    Rancés Castillo Lara

    2011-01-01

    conveniente para el hormigón ante la posible acción de diferentes mecanismos de degradación.Currently economical and environmental advantages of cement clinker replacement by other supplementary cementious materials are well known. For example calcined clays, such as metakaolin, have drawn special attention during recent years. It is well known that these admixtures added to mortars and concretes improve mechanical strength as well as durability. The purpose of this study is to evaluate the behavior of physical-mechanical properties and durability in micro-concretes, by employing calcinated and grinded clays as replacement material, by 30% of ordinary Portland cement (OPC. Therefore, clay soil was employed, which is mainly composed by low-purity-kaolin mineral, so as to obtain calcined clays to be used as supplementary cementious minerals. Best results for compressive strength at 28 days were obtained by sedimentary calcined clays, which have higher content of kaolin mineral thanks to a purification process by means of raw material sedimentation conducted on this admixture only. Nevertheless, capillary water absorption tests delivered best results for calcined clay soil, which finesse is quite high. Lower values showed by this admixture, as much for capillary porosity and sorptivity, revealed there was a predominance of compaction and impermeability phenomena achieved by cementious matrix using such fine material, over the effect of puzzolanic reaction. Micro-structure studies on C-S-H gel, employing energy dispersive x-ray (EDX technique, demonstrated that the use of calcined clays as replacement of RPC favors the creation of quite stable hydration products, mainly monosulfos of hemicabo and monocarbo types, which is convenient for concrete against possible deterioration actions from different mechanisms.

  2. Multivariate optimization of process parameters in the synthesis of calcined Ca‒Al (NO3) LDH for defluoridation using 3(3) factorial, central composite and Box-Behnken design.

    Science.gov (United States)

    Ghosal, Partha S; Gupta, Ashok K; Sulaiman, Ayoob

    2016-01-01

    Response surface methodology was applied for the first time in the optimization of the preparation of layered double hydroxide (LDH) for defluoridation. The influence of three vital process parameters (viz. pH, molar ratio and calcination temperature) in the synthesis of the adsorbent 'Calcined Ca‒Al (NO3) LDH' was thoroughly examined to maximize its fluoride scavenging potential. The process parameters were optimized using the 3(3) factorial, face centered central composite and Box-Behnken designs and a comparative assessment of the methods was conducted. The maximum fluoride removal efficiency was achieved at a calcination temperature of approximately 500ºC; however, the efficiency decreased with increasing pH and molar ratio. The outcome of the comparative assessment clearly delineates the case specific nature of the models. A better predictability over the entire experimental domain was obtained with the 3(3) factorial method, whereas the Box-Behnken design was found to be the most efficient model with lesser number of experimental runs. The desirability function technique was performed for optimizing the response, wherein face centered central composite design exhibited a maximum desirability. The calcined Ca‒Al (NO3) LDH, synthesized under the optimum conditions, demonstrated the removal efficiencies of 95% and 99% for the doses of 3 g L(-1) and 5 g L(-1), respectively.

  3. Comparative evaluation of glasses reprocessing and reversible conditioning of calcinates; Evaluation comparative de la reprise des verres et du conditionnement reversible des calcinats

    Energy Technology Data Exchange (ETDEWEB)

    Boen, R

    2000-01-15

    Fission products and minor actinides separated during the spent fuel reprocessing treatment are industrially vitrified on-line and thus confined inside a glass matrix with admittedly durability properties. In the framework of the feasibility of a reversible conditioning, this document examines first the possible alternative ways of conditioning and storage of calcinates before vitrification, which may simplify the reversibility aspect. Such a conditioning must be compatible with the storage process, with a possible extraction of actinides and long-lived fission products, and with the vitrification process if no extraction is performed. Calcinates are pulverulent and comprise an important soluble fraction, a proportion of nitrates of about 30%, and release a high thermal power (17 kW/m{sup 3}) combined to a low thermal conductivity (0.1 to 0.15 W.m{sup -1} k{sup -1}). Among the different foreseeable solutions (denitration, mixing with another material, with or without compacting, dissolution inside another material..), the dissolution inside a borate seems to be the most acceptable with respect to the safety, feasibility and vitrification aspects. The thermal aspect of the storage remains complex as a specific container is necessary. In a second part, this report analyzes the possibility to re-extract back the long-lived radionuclides from vitrified wastes. The different possible ways to destroy the glass structure and to transfer the fission products and minor actinides in an aqueous solution compatible with an hydrometallurgical separation process are explored. Two processes are foreseeable: a low temperature dissolution process which requires a preliminary crushing and the handling of huge amounts of acids, and a both high and low temperature process which comprises the following steps: melting, fractionation by water tempering, addition of Na{sub 2}O or sodium tetraborate to make it sensible to hot leaching, separation of fission products and minor actinides

  4. Influence of calcinable cylinders cast in cobalt-chromium alloy on the passivity of implant-supported frameworks = Influência de cilindros calcináveis fundidos em cobalto-cromo na passividade de próteses implanto-suportadas

    Directory of Open Access Journals (Sweden)

    Triches, Diego Fernandes

    2009-01-01

    Full Text Available Objetivo: Este trabalho avaliou a influência da utilização de cilindros calcináveis no grau de passividade de infra-estruturas que simulam uma prótese parcial fixa de três elementos sobre dois implantes. Metodologia: Foram utilizados dois implantes de hexágono externo de 3,75 mm×10 mm, com seus respectivos pilares intermediários, fixados numa base de aço, formando o modelomestre. A partir disto, foram fabricadas dez infra-estruturas em liga de cobalto-cromo através da técnica de fundição por indução. Foram criados dois grupos: Grupo 1 utilizando cilindros pré-usinados para a fabricação de cinco infra-estruturas; Grupo 2 cinco infra-estruturas fundidas com cilindros de plástico calcináveis. Para avaliação da passividade foram utilizados extensômetros colados na região oclusal e cervical do pôntico das infra-estruturas. A medição foi realizada no momento do aperto do segundo parafuso protético com torque de 10Ncm. Os dados foram analisados pelo teste t de Student (a=0,05. Resultados: As médias (desvio-padrão dos grupos foram de 39,16 (24,74 mV/V no Grupo 1 e 43,76 (21,13 mV/V no Grupo 2. Não houve diferença estatisticamente significante entre os grupos (P=0,815. Conclusão: Considerando-se as limitações deste trabalho, sugere-se que o uso de cilindros calcináveis obtém o mesmo grau de passividade que o uso de cilindros pré-usinados

  5. Hydrogen-Rich Gas Production by Sorption Enhanced Steam Reforming of Woodgas Containing TAR over a Commercial Ni Catalyst and Calcined Dolomite as CO2 Sorbent

    Directory of Open Access Journals (Sweden)

    Vincenzo Naso

    2013-07-01

    Full Text Available The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR and CH4 and to produce pure H2 by means of a CO2 sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolomite (CaO/MgO. The bed material simultaneously acts as reforming catalyst and CO2 sorbent. The experimental investigations have been carried out in a fixed bed micro-reactor rig using a slipstream from the gasifier to evaluate gas cleaning and upgrading options. The reforming/sorption tests were carried out at 650 °C while regeneration of the sorbent was carried out at 850 °C in a nitrogen environment. Both combinations of catalyst and sorbent are very effective in TAR and CH4 removal, with conversions near 100%, while the simultaneous CO2 sorption effectively enhances the water gas shift reaction producing a gas with a hydrogen volume fraction of over 90%. Multicycle tests of reforming/CO2 capture and regeneration were performed to verify the stability of the catalysts and sorbents to remove TAR and capture CO2 during the duty cycle.

  6. Industrial fluorosis of farm animals in England, attributable to the manufacture of bricks, the calcining of ironstone, and to enamelling processes

    Energy Technology Data Exchange (ETDEWEB)

    Blakemore, F; Bosworth, T J; Green, H H

    1948-01-01

    An account is given of the occurrence in England of fluorosis in farm animals arising from industrial contamination of pasture due to the manufacture of bricks, the calcining of ironstone, and the fumes from a color and enamel factory. It is shown that the contamination of vegetation is entirely superficial and not due to fluorine compounds carried down into the soil by rain. The origin of the aerial fluorine is discussed in relation to the industrial processes involved, and extent of damage related to distance from source and direction of prevailing wind. A map showing levels of pasture contamination (7 ppm to 90 ppm) is given, and this is discussed in relation to the severity of clinical symptoms in animals. Considerable differences were observed in regard to susceptibility of different classes of stock. Urinary analysis was found to be a convenient way of diagnosing fluorosis, especially in sub-clinical cases where no dental signs or obvious skeletal changes were present. By correlating urinary excretion with fluorine values on rib bone removed surgically in an animal taken away from the source of fluorine ingestion, it was found that about half of the original skeletal fluorine still remained after eight months and that, although marked clinical improvement occurred quite soon, urinary values remained far above normal (13 ppm) in equilibrium with the very slow change of bone values in the later stages of skeletal reconstruction.

  7. Transition metal modified and partially calcined inorganic-organic pillared clays for the adsorption of salicylic acid, clofibric acid, carbamazepine, and caffeine from water.

    Science.gov (United States)

    Cabrera-Lafaurie, Wilman A; Román, Félix R; Hernández-Maldonado, Arturo J

    2012-11-15

    Pharmaceutical and Personal Care Products (PPCPs) are considered emerging contaminants, and their efficient removal from water is going to be a challenging endeavor. Microporous adsorbent materials, including pillared clays, could offer a potential solution if tailored properly. Although pillared clays have been employed previously for the removal of organics, the effective removal of PPCPs will only be possible if their surface and textural properties are manipulated from the bottom-up. This work presents the use of modified inorganic-organic pillared clays (IOCs) for the adsorption of salicylic acid, clofibric acid, carbamazepine, and caffeine. The IOCs have been modified with Co(2+), Cu(2+), or Ni(2+) to induce complexation-like adsorbate-adsorbent interactions at ambient conditions, in an attempt to provide an efficient and yet reversible driving force in the sub-ppm concentration range. Furthermore, the IOCs were partially calcined to increase effective surface area by an order of magnitude while preserving some hydrophobicity. In general, the Ni(2+) IOCs exhibited the greatest interaction with salicylic and clofibric acids, respectively, while the Co(2+) adsorbents excelled at adsorbing caffeine at low concentrations. All of the metal-modified IOCs showed comparable adsorption capacities for the case of carbamazepine, probably due to the lack of availability of particular functional groups in this adsorbate. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Stabilization of Pb²⁺ and Cu²⁺ contaminated firing range soil using calcined oyster shells and waste cow bones.

    Science.gov (United States)

    Moon, Deok Hyun; Cheong, Kyung Hoon; Khim, Jeehyeong; Wazne, Mahmoud; Hyun, Seunghun; Park, Jeong-Hun; Chang, Yoon-Young; Ok, Yong Sik

    2013-05-01

    Pb(2+) and Cu(2+) contamination at army firing ranges poses serious environmental and health risks to nearby communities necessitating an immediate and prompt remedial action. In this study, a novel mixture of calcined oyster shells (COSs) and waste cow bones (WCBs) was utilized to immobilize Pb(2+) and Cu(2+) in army firing range soils. The effectiveness of the treatment was evaluated based on the Korean Standard leaching test. The treatment results showed that Pb(2+) and Cu(2+) immobilization in the army firing range soil was effective in significantly reducing Pb(2+) and Cu(2+) leachability upon the combined treatment with COS and WCB. A drastic reduction in Pb(2+) (99%) and Cu(2+) leachability (95%) was obtained as compared to the control sample, upon treatment with 5 wt.% COS and 5 wt.% WCB. The combination treatment of COS and WCB was more effective for Pb immobilization, than the treatment with COS or WCB alone. The 5 wt.% COS alone treatment resulted in 95% reduction in Cu(2+) leachability. The SEM-EDX results suggested that Pb(2+) and Cu(2+) immobilization was most probably associated with the formation of ettringite, pozzolanic reaction products and pyromorphite-like phases at the same time. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Ni/Fe and Mg/Fe layered double hydroxides and their calcined derivatives: preparation, characterization and application on textile dyes removal

    Directory of Open Access Journals (Sweden)

    Rachid Elmoubarki

    2017-07-01

    Full Text Available In this study, Mg/Fe and Ni/Fe layered double hydroxides (LDHs with molar ratio (M2+/Fe3+ of 3 and intercalated with carbonate ions were synthesized by co-precipitation method. The as-synthesized materials and their calcined products (CLDHs were characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FT-IR, thermo-gravimetric and differential thermal analyses (TGA–DTA, transmission electron microscopy coupled with energy dispersive X-ray spectroscopy (TEM-EDX, inductively coupled plasma (ICP and elemental chemical analysis CHNSO. The materials were used as adsorbents for the removal availability of textile dyes from aqueous solution. Methylene blue (MB and malachite green (MG, representative of cationic dyes, and methyl orange (MO representative of anionic dyes were used as model molecules. Adsorption experiments were carried out under different parameters such as contact time, temperature, initial dyes concentration and solution pH. Experimental results indicate that CLDHs had much higher adsorption capacities compared to LDHs. Adsorption kinetic data fitted well the pseudo-second order kinetic model. The process was spontaneous, endothermic for cationic dyes and exothermic for the anionic dye. Equilibrium sorption data fitted the Langmuir model instead of Freundlich model.

  10. Prevention of the growth of algae and protests in water treated with a calcinated sand; Ceramics seihin ni yoru suisochu no soruinado no hassei boshi

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, K.; Kakita, Y. [Fukuoka University, Fukuoka (Japan). Faculty of Pharmaceutical Science; Tanaka, A.; Yamasaki, K.; Masamoto, H.; Nakahara, S. [Fukuoka University, Fukuoka (Japan). Faculty of Engineering; Egashira, K. [Kyudenko Corp., Fukuoka (Japan)

    1995-07-10

    A commercial calcinated sand, Cleansand-205 (abbr. Kls-205 : a silica sand coated by a special procedure with a mixture of the oxides of Si, Al, Ti, and Ag), was tested for its ability to inhibit the growth of algae in a laboratory (batch-system) experiment. The growth of algae in water taken from a domestic gold fish basin was inhibited almost completely by about 5% (w/v) of Kls-205, under the conditions where fairly amounts of both nitrogen and phosphorus were present. However, Kls-205 (5%) showed little inhibition on algae which had already abundantly grown, and did not suppress further growth. The abilities of Kls-205 to adsorb nitrogen, phosphorus and carbon dioxide required for the growth and photosynthesis of algae were weak. The amounts of beta- and gamma-radiation and harmful heavy metal ions were the same levels as those from non-treated natural water. The dissolution of any antialgal substances and the generation of active oxygens were not observed. The possible role of Ag and/or its oxide with oligodynamie in inhibiting the growth of algae by Kls-205 was discussed. 15 refs., 4 figs., 2 tabs.

  11. Effect of the calcining temperature on the porosity of the titanium dioxide powders obtained by Polymeric Precursor Method; Efeito da temperatura de calcinacao na porosidade de pos de dioxido de titanio obtidos pelo Metodo dos Precursores Polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Silva, D.W.; Granado, S.R.; Ciola, R.A.; Cavalheiro, A.A., E-mail: douglas_levis@hotmail.com [Universidade Estadual de Mato Grosso do Sul (CPTREN/UEMS), Navirai, MS (Brazil). Centro de Pesquisas Tecnologicas em Recursos Naturais

    2011-07-01

    Ceramics materials obtained by Polymeric Precursor Method exhibit mechanisms of the pore formation and elimination dependents on the decomposition kinetics of the residual organic matter of the polyester. The mechanism of pore elimination seems to occur by disrupting of the wall among the pores because it leads to the consequent pore coalescence and increasing in pore volume, which posses higher pore diameters. In this case, it was observed that the porosity decreasing occurs by pore wall moving after that the residual organic matter is eliminated from the pore inside. The pore diameter associated to the highest volume desorption occurred for the material obtained after calcining at 450°C is approximately 1,7 nm, what seems to be related to the amorphous carbon accumulated inside the pores, once that the pore volume decreases more effectively for the material obtained by calcining at 550°C, making the maximum volume situates at 2,0 nm. (author)

  12. Effect of calcination temperature on the structure and performance of CeO{sub x}–MnO{sub x}/TiO{sub 2} nanoparticles for the catalytic combustion of chlorobenzene

    Energy Technology Data Exchange (ETDEWEB)

    He, Fei; Chen, Yong; Zhao, Pei; Liu, Shantang, E-mail: anliu123@hotmail.com [Wuhan Institute of Technology, Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemistry and Environmental Engineering (China)

    2016-05-15

    In this study, MnO{sub x}/TiO{sub 2}, CeO{sub x}/TiO{sub 2}, and CeO{sub x}–MnO{sub x}/TiO{sub 2} catalysts were prepared by the homogeneous precipitation method. The effect of calcination temperature on the structure and catalytic performance of CeO{sub x}–MnO{sub x}/TiO{sub 2} mixed oxide catalyst in the catalytic combustion of chlorobenzene was investigated. The samples were characterized by X-ray diffraction, nitrogen adsorption–desorption, transmission electron microscopy, Raman spectra, hydrogen temperature-programmed reduction, and X-ray photoelectron spectroscopy. The results indicate that calcination significantly affect the activity of the prepared catalysts. When calcined at a low temperature such as 400 °C, Ce, and Mn species form a solid solution of MnCeO{sub x} in the catalyst, thus locating the O atoms in a perturbed chemical surrounding in the catalysts. This increases the mobility of the O atoms during the reaction, probably contributing to the highest catalytic activity of CeO{sub x}–MnO{sub x}/TiO{sub 2} among all the tested catalysts. However, a further increase in the calcination temperature decreased the performance of the catalyst for the catalytic combustion of chlorobenzene. This is probably because of a reduction in surface chemisorbed oxygen concentration, a decrease in the interface area between metal oxides and MnCeO{sub x} caused by the isolation of MnO{sub x} or CeO{sub 2} from MnCeO{sub x}, and a decrease in the specific surface area of CeO{sub x}–MnO{sub x}/TiO{sub 2} catalyst due to the sintering of catalyst.Graphical Abstract.

  13. Effect of calcination temperature on the H{sub 2}O{sub 2} decomposition activity of nano-crystalline Co{sub 3}O{sub 4} prepared by combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf, M.Th. [Chemistry Department, Faculty of Science, Assiut University, 71516 Assiut (Egypt); Abu-Zied, B.M., E-mail: babuzied@aun.edu.eg [Chemistry Department, Faculty of Science, Assiut University, 71516 Assiut (Egypt); Mansoure, T.H. [Chemistry Department, Faculty of Science, Assiut University, 71516 Assiut (Egypt)

    2013-06-01

    Cobalt oxide nano-particles were prepared by combustion method using urea as a combustion fuel. The effects of calcination temperature, 350–1000 °C, on the physicochemical, surface and catalytic properties of the prepared Co{sub 3}O{sub 4} nano-particles were studied. The products were characterized by thermal analyses (TGA and DTA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. Textural features of the obtained catalysts were investigated using nitrogen adsorption at −196 °C. X-ray diffraction confirmed that the resulting oxide was pure single-crystalline Co{sub 3}O{sub 4} nano-particles. Transmission electron microscopy indicating that, the crystallite size of Co{sub 3}O{sub 4} nano-crystals was in the range of 8–34 nm. The catalytic activities of prepared nano-crystalline Co{sub 3}O{sub 4} catalysts were tested for H{sub 2}O{sub 2} decomposition at 35–50 °C temperature range. Experimental results revealed that, the catalytic decomposition of H{sub 2}O{sub 2} decreases with increasing the calcination temperature. This was correlated with the observed particle size increase accompanying the calcination temperature rise.

  14. Effects of calcination temperature on phase formation and particle size of Zn{sub 2}Nb{sub 34}O{sub 87} powder synthesized by solid-state reaction

    Energy Technology Data Exchange (ETDEWEB)

    Amonpattaratkit, Penphitcha, E-mail: p.amonpattaratkit@gmail.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Ananta, Supon, E-mail: suponananta@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-05-15

    The solid-state mixed oxide method via a rapid vibro-milling technique was explored for the preparation of single-phase Zn{sub 2}Nb{sub 34}O{sub 87} nanopowders. Phase formation of zinc niobate was investigated as a function of calcination temperature by using a combination of thermogravimetric/differential thermal analyzer (TG/DTA) and X-ray diffraction (XRD) techniques. Morphology, particle size and chemical composition of the powders were determined by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) technique. The obtained results clearly revealed the influences of calcination temperature on phase formation and particle size of Zn{sub 2}Nb{sub 34}O{sub 87} nanopowder. - Highlights: ► Single phase Zn{sub 2}Nb{sub 34}O{sub 87} was firstly prepared by solid-state mixed oxide method via a rapid vibro-milling technique. ► The influences of calcination temperature on phase formation and particle size were investigated. ► Zn{sub 2}Nb{sub 34}O{sub 87} powders were characterized by TG–DTA, XRD, SEM and EDX.

  15. Preparation and properties of Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} by spray-drying and post-calcining method

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bo; Li, Xinhai, E-mail: yangbo@csu.edu.cn; Guo, Huajun; Wang, Zhixing; Xiao, Wei

    2015-09-15

    Highlights: • The spray-drying method is a simple and energy-saving method to prepare LATP. • The compounds with single phase structure of LATP were synthesized at 700–900 °C. • The ionic conductivity of the prepared LATP was maximized at 0.622 mS cm{sup −1} at 800 °C. - Abstract: Solid state electrolyte Li{sub 1.3}Al{sub 0.3}Ti{sub 1.7}(PO{sub 4}){sub 3} is synthesized by spray-drying and post-calcining method. X-ray diffraction is employed to characterize the powders calcined in the range of 700–900 °C for 2 h, which indicates powders are well crystallized. FTIR shows trivalent cation Al{sup 3+} is substituted by Ti{sup 4+}. The composite material appears as 2–5 μm spherical particle. TG–DTA results confirm that the thermal decomposition of precursors obtained by spray-drying method occurred at lower temperature compares with solid phase synthesis method and sol–gel method. The ionic conductivity of the pellets reaches a maximum of 0.622 mS cm{sup −1} at calcining temperature of 800 °C.

  16. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaoming [State Key Laboratory of Advanced Metallurgy, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhang, Na [Green Construction Materials and Circulation Economy Center, Architectural Design and Research Institute of Tsinghua University Co., Ltd., Beijing 100084 (China); Yao, Yuan, E-mail: yuanyaocas@163.com [School of Engineering and Computer Science, University of the Pacific, Stockton, CA 95211 (United States); Sun, Henghu; Feng, Huan [School of Engineering and Computer Science, University of the Pacific, Stockton, CA 95211 (United States)

    2013-11-15

    Highlights: • Al{sup IV} and Al{sup VI} both exist in the hydration products. • Increase of Ca/Si ratio promotes the conversion from [AlO{sub 4}] to [AlO{sub 6}]. • Polymerization degree of [SiO{sub 4}] in the hydration products declines. -- Abstract: In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, {sup 27}Al MAS NMR and {sup 29}Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si + Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al{sup IV} and Al{sup VI}, but mainly in the form of Al{sup VI}. Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO{sub 4}] to [AlO{sub 6}] and inhibits the combination between [AlO{sub 4}] and [SiO{sub 4}] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO{sub 4}] in the hydration products declines.

  17. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials.

    Science.gov (United States)

    Liu, Xiaoming; Zhang, Na; Yao, Yuan; Sun, Henghu; Feng, Huan

    2013-11-15

    In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, (27)Al MAS NMR and (29)Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si+Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al(IV) and Al(VI), but mainly in the form of Al(VI). Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO4] to [AlO6] and inhibits the combination between [AlO4] and [SiO4] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO4] in the hydration products declines. Published by Elsevier B.V.

  18. Micro-structural characterization of the hydration products of bauxite-calcination-method red mud-coal gangue based cementitious materials

    International Nuclear Information System (INIS)

    Liu, Xiaoming; Zhang, Na; Yao, Yuan; Sun, Henghu; Feng, Huan

    2013-01-01

    Highlights: • Al IV and Al VI both exist in the hydration products. • Increase of Ca/Si ratio promotes the conversion from [AlO 4 ] to [AlO 6 ]. • Polymerization degree of [SiO 4 ] in the hydration products declines. -- Abstract: In this research, the micro-structural characterization of the hydration products of red mud-coal gangue based cementitious materials has been investigated through SEM-EDS, 27 Al MAS NMR and 29 Si MAS NMR techniques, in which the used red mud was derived from the bauxite calcination method. The results show that the red mud-coal gangue based cementitious materials mainly form fibrous C-A-S-H gel, needle-shaped/rod-like AFt in the early hydration period. With increasing of the hydration period, densification of the pastes were promoted resulting in the development of strength. EDS analysis shows that with the Ca/Si of red mud-coal gangue based cementitious materials increases, the average Ca/Si and Ca/(Si + Al) atomic ratio of C-A-S-H gel increases, while the average Al/Si atomic ratio of C-A-S-H gel decreases. MAS NMR analysis reveals that Al in the hydration products of red mud-coal gangue based cementitious materials exists in the forms of Al IV and Al VI , but mainly in the form of Al VI . Increasing the Ca/Si ratio of raw material promotes the conversion of [AlO 4 ] to [AlO 6 ] and inhibits the combination between [AlO 4 ] and [SiO 4 ] to form C-A-S-H gel. Meanwhile, the polymerization degree of [SiO 4 ] in the hydration products declines

  19. Effect of hexagonal boron nitride and calcined petroleum coke on friction and wear behavior of phenolic resin-based friction composites

    International Nuclear Information System (INIS)

    Yi Gewen; Yan Fengyuan

    2006-01-01

    Calcined petroleum coke (CPC) and hexagonal boron nitride (h-BN) were used as the friction modifiers to improve the friction and wear properties of phenolic resin-based friction composites. Thus, the composites with different relative amounts of CPC and h-BN as the friction modifiers were prepared by compression molding. The hardness and bending strength of the friction composites were measured. The friction and wear behaviors of the composites sliding against cast iron at various temperatures were evaluated using a pin-on-disc test rig. The worn surfaces and wear debris of the friction composites were analyzed by means of scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. It was found that the hybrid of the two friction modifiers was effective to significantly decrease the wear rate and stabilize the friction coefficient of the friction composites at various temperatures by forming a uniform lubricating and/or transferred film on the rubbing surfaces. The uniform and durable transfer films were also able to effectively diminish the direct contact between the friction composite and the cast iron counterpart and hence prevent severe wear of the latter as well. The effectiveness of the hybrid of CPC and h-BN in improving the friction and wear behavior of the phenolic resin-based friction modifiers could be attributed to the complementary action of the 'low temperature' lubricity of CPC and the 'high temperature' lubricity of h-BN. The optimum ratio of the two friction modifiers CPC and h-BN in the friction composites was suggested to be 1:1, and the corresponding friction composite showed the best friction-reducing and antiwear abilities

  20. Fall 2010 Semiannual (III.H. and I.U.) Report for the HWMA/RCRA Post Closure Permit for the INTEC Waste Calcining Facility and the CPP 601/627/640 Facility at the INL Site

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, Ann

    2010-11-01

    The Waste Calcining Facility is located at the Idaho Nuclear Technology and Engineering Center. In 1999, the Waste Calcining Facility was closed under an approved Hazardous Waste Management Act/Resource Conservation and Recovery Act (HWMA/RCRA) Closure Plan. Vessels and spaces were grouted and then covered with a concrete cap. The Idaho Department of Environmental Quality issued a final HWMA/RCRA post-closure permit on September 15, 2003, with an effective date of October 16, 2003. This permit sets forth procedural requirements for groundwater characterization and monitoring, maintenance, and inspections of the Waste Calcining Facility to ensure continued protection of human health and the environment. The post closure permit also includes semiannual reporting requirements under Permit Conditions III.H. and I.U. These reporting requirements have been combined into this single semiannual report, as agreed between the Idaho Cleanup Project and Idaho Department of Environmental Quality. The Permit Condition III.H. portion of this report includes a description and the results of field methods associated with groundwater monitoring of the Waste Calcining Facility. Analytical results from groundwater sampling, results of inspections and maintenance of monitoring wells in the Waste Calcining Facility groundwater monitoring network, and results of inspections of the concrete cap are summarized. The Permit Condition I.U. portion of this report includes noncompliances not otherwise required to be reported under Permit Condition I.R. (advance notice of planned changes to facility activity which may result in a noncompliance) or Permit Condition I.T. (reporting of noncompliances which may endanger human health or the environment). This report also provides groundwater sampling results for wells that were installed and monitored as part of the Phase 1 post-closure period of the landfill closure components in accordance with HWMA/RCRA Landfill Closure Plan for the CPP-601 Deep

  1. Effects of Li source and calcination temperature on the electrochemical properties of LiNi{sub 0.5}Co{sub 0.2}Mn{sub 0.3}O{sub 2} lithium-ion cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Ji-Zhou [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, No. 29 Yudao Street, Nanjing 210016 (China); Zhou, Fei, E-mail: fzhou@nuaa.edu.cn [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, No. 29 Yudao Street, Nanjing 210016 (China); Wang, Chuan-Bao; Yang, Xiao-Yan [State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, No. 29 Yudao Street, Nanjing 210016 (China); Zhai, Hai-Fa; Li, Hui [Materials Science and Engineering Department, National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Li, Jun-Xiu; Tang, Zhou; Zhang, Shi-Qin [Jiangsu Cobalt Nickel Metal Co., Ltd. (KLK), Taixing 225404 (China)

    2013-03-25

    Highlights: ► Instead of ammonia, oxalic acid was used as chelating agent to prepare the hydroxide precursor. ► Effects of Li source and calcination temperature on physical and electrochemical properties were investigated. ► LiCO{sub 3} was considered as a more suitable Li source, compared with LiNO{sub 3}. ► The optimal calcination temperature was considered to be 850 °C. ► This sample exhibited excellent discharge capacity, cycle stability and rate capability. -- Abstract: Spherical Ni{sub 0.5}Co{sub 0.2}Mn{sub 0.3}(OH){sub 2} precursor was prepared via co-precipitation method using oxalic acid as chelating agent. And layered structure Li(Ni{sub 0.5}Co{sub 0.2}Mn{sub 0.3})O{sub 2} cathode materials were synthesized by calcining the mixture of different lithium salts and hydroxide precursor (Ni{sub 0.5}Co{sub 0.2}Mn{sub 0.3})(OH){sub 2} at the temperatures ranged from 800 to 900 °C. The effects of the Li source and calcination temperature on physical and electrochemical properties of the electrode samples were deeply investigated. And Li{sub 2}CO{sub 3} is considered to be the suitable Li source for the synthesis of Li[Ni{sub 0.5}Co{sub 0.2}Mn{sub 0.3}]O{sub 2}. The results also show the sample calcined at 850 °C gives the highest integrated intensity ratio I{sub (003)}/I{sub (104)}, indicating that this sample has the lowest amount of cation mixing. At the same time, this sample shows excellent electrochemical properties, such as the largest initial discharge capacity of 176 mAh g{sup −1} at 0.1 C, best cycle stability of about 100% at 0.2 C and highest rate capability.

  2. Synthesis of aluminum oxide by the polymer precursor method (Pechini) in 4: 1 ratio of citric acid: metal cation: calcination temperature effect; Sintese do oxido de aluminio pelo metodo dos precursores polimericos (Pechini) na relacao 4:1 de acido citrico: cation metalico: efeito da temperatura de calcinacao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.C.; Lira, H.L.; Ribeiro, P.C.; Freitas, N.L., E-mail: mirelecsilva@hotmail.com [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2014-07-01

    The technology field is nanopowders prominent in science since these materials fall in various sectors regarding their applications. This work aims at the synthesis of aluminum oxide by polymeric precursors in 4:1 ratio of citric acid:metal cation and evaluate the influence of calcination temperature on their structural and morphological characteristics. The samples after reaction were characterized by XRD and thermal analysis. After calcination 500-1200°C the samples were characterized by XRD, SEM and particle size distribution. The results showed that the variation of the calcination temperature is sufficient to achieve a same material with different structural and morphological characteristics. The most stable phase aluminum oxide arose only after calcination at 1100°C, below 900°C, the amorphous material appeared. As regards the morphology, the change was not as significant as compared to the structure. (author)

  3. Process for calcining a material

    International Nuclear Information System (INIS)

    Ross, D.R.

    1981-01-01

    This invention is directed to a method and an apparatus to heat certain particles. These certain particles are heated to make them more desirable. In the heating of these particles, it is often desirable to expand the particles to make a light-weight aggregate. The light-weight aggregate may be used in making a building material or the like. In carrying out the process of heating these particles, there is used air for combustion of the combustible fuel and only a minimum of air for carrying of the particles or expansion of the particles

  4. Production of BaAl_2O_4 doped with Eu"3"+ in low temperature: research of the influence of the synthesis route, temperature and calcination time in the optical properties

    International Nuclear Information System (INIS)

    Gomes, Manasses Almeida

    2017-01-01

    In this work, the synthesis condition (complexing agent and temperature and time of calcination) were studied aiming to produce BaAl_2O_4 samples in the ferroelectric hexagonal phase. Pure and Eu"3"+ - doped samples were produced and its luminescent properties were investigated. BaAl_2O_4 was prepared using several thermal treatment conditions, via an alternative sol-gel route, using coconut water or PVA as the complexing agents. The sample production at 600 °C/5h is quite interesting, since to date the lowest calcination temperatures found in the literature was 650 ° C using reagents with high degree of toxicity DTA / TG measurements indicated a possible start of the crystallization of the material at approximately 600 ° C, and the X-ray powder diffraction (XRD) confirm the formation of the desired phase of the calcined barium aluminate at that temperature. The results of the Rietveld refinements showed the occurrence of secondary phase in the samples produced at 600 ° C / 5h, presenting 5% of phase Ba(NO_3)_2, while single phase was found for samples calcined at 1200 ° C for 2 and 5h. Analysis of the diffractogram by the Scherrer equation showed smaller crystallite size for samples calcified at 600 °C/5h, but apparently with a lower degree of crystallinity than the sample prepared at 1200 ° C/ 2 and 5h. The photoluminescence measurements showed that the emission spectra of the samples have great dependence on the times, temperatures and complexing agents used. In particular, samples calcined at 600 ° C have very different characteristics with regard to the probabilities of emissions associated with Eu"3"+ when compared with samples produced at higher temperatures. Differences observed in the spectra of samples produced via different complexing agents are possibly due to defects created in the materials by impurities present in the coconut water. Samples produced using PVA present sites with higher symmetry, which was evidenced by a lower relative emission

  5. Effects of calcining temperatures of Eu{sup 2+} and Dy{sup 3+} ion-codoped calcia-alumina binary compounds on their phase transition and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Chen-Jui, E-mail: cjliang@fcu.edu.tw; Siao, Hao-Yi

    2017-06-01

    In this study, phase evolution as a function of calcining temperature in calcia-alumina binary compound phosphors was examined to interpret their luminescence properties. The binary compounds were prepared through a coprecipitation method employing potassium carbonate as the precipitant to obtain precursors with a high-precision stoichiometric composition for the calcination. The results indicate that the morphology, surface properties, and infrared transmittance of the prepared phosphors were affected by the calcining temperature. X-ray diffraction analysis results enabled identification of Ca{sub 12}Al{sub 14}O{sub 33}, CaAl{sub 2}O{sub 4}, and CaAl{sub 4}O{sub 7} phase transitions at various calcining temperatures. The amount of the CaAl{sub 2}O{sub 4} phase increased with the calcining temperature within the range of 700–1060 °C. The Ca{sub 12}Al{sub 14}O{sub 33} and CaAl{sub 4}O{sub 7} phases exhibited trends opposite to that of the CaAl{sub 2}O{sub 4} phase. When the calcining temperature reached 980 °C, the CaAl{sub 2}O{sub 4} phase (60.5%) was determined to be the main phase in the structure, and excellent emission intensity at an emission band of 449 nm was observed as a result of the complete substitution of Eu{sup 2+} for Ca{sup 2+}. The emission intensity corresponding to Eu{sup 2+} 4f{sup 6}5d{sup 1} → 4f{sup 7} decreased slightly when the temperature reached 1060 °C because of more monoclinic reciprocal CaAl{sub 4}O{sub 7} phase (81.5%) formation, causing the transfer of some Eu{sup 2+} to Eu{sup 3+}, during which strong photoluminescence spectra of Eu{sup 3+5}D{sub 0} → {sup 7}F{sub j} (j = 0, 1, 2, 3, 4) within the wavelength range of 570–720 nm were observed. Because the strong photoluminescence spectra of the Eu{sup 2+} and Eu{sup 3+} emissions were together within the wavelength range of 449–720 nm in this phosphor, the photoluminescence was white light. One moderately intense emission band in the infrared region was observed and

  6. Potential rare-earth modified CeO{sub 2} catalysts for soot oxidation. Part III. Effect of dopant loading and calcination temperature on catalytic activity with O{sub 2} and NO + O{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, K.; Bueno-Lopez, A.; Makkee, M.; Moulijn, J.A. [Catalysis Engineering, DelftChemTech, Delft University of Technology, Julianalaan 136, NL 2628 BL Delft (Netherlands)

    2007-09-26

    CeO{sub 2} and CeReO{sub xy} catalysts are prepared by the calcination at different temperatures (y = 500-1000 C) and having a different composition (Re = La{sup 3+} or Pr{sup 3+/4+}{sub ,} 0-90 wt.%). The catalysts are characterised by XRD, H{sub 2}-TPR, Raman, and BET surface area. The soot oxidation is studied with O{sub 2} and NO + O{sub 2} in the tight and loose contact conditions, respectively. CeO{sub 2} sinters between 800-900 C due to a grain growth, leading to an increased crystallite size and a decreased BET surface area. La{sup 3+} or Pr{sup 3+/4+} hinders the grain growth of CeO{sub 2} and, thereby, improving the surface catalytic properties. Using O{sub 2} as an oxidant, an improved soot oxidation is observed over CeLaO{sub xy} and CePrO{sub xy} in the whole dopant weight loading and calcination temperature range studied, compared with CeO{sub 2}. Using NO + O{sub 2}, the soot conversion decreased over CeLaO{sub xy} catalysts calcined below 800 C compared with the soot oxidation over CeO{sub 2y}. CePrO{sub xy}, on the other hand, showed a superior soot oxidation activity in the whole composition and calcination temperature range using NO + O{sub 2}. The improvement in the soot oxidation activity over the various catalysts with O{sub 2} can be explained based on an improvement in the external surface area. The superior soot oxidation activity of CePrO{sub xy} with NO + O{sub 2} is explained by the changes in the redox properties of the catalyst as well as surface area. CePrO{sub xy}, having 50 wt.% of dopant, is found to be the best catalyst due to synergism between cerium and praseodymium compared to pure components. NO into NO{sub 2} oxidation activity, that determines soot oxidation activity, is improved over all CePrO{sub x} catalysts. (author)

  7. Study of the calcination temperature in samples of calcium phosphate synthesized by the method of direct way; Estudo da temperatura de calcinacao em amostras de fosfatos de calcio sintetizadas pelo metodo de via direta

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M.G.; Santos, P.T.A.; Costa, A.C.F.M, E-mail: patyquimica@hotmail.com [Universidade Federal de Campina Grande (DEMA/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais

    2012-07-01

    The use of phosphates in bioceramics have attracted the interest of many researchers, especially when it is in the Ca / P = 1.67, which allows the obtention of the hydroxyapatite. This work aims to investigate different calcination temperatures on the structural and morphological characteristics of samples of calcium phosphates synthesized by the method of direct way, aiming for hydroxyapatite as a major phase. For this purpose, we used the calcium hydroxide and phosphoric acid in the Ca / P = 1.67. The samples were calcined at temperatures of 600, 700, 800, 900, 1000, 1100, 1200 and 1350°C/2h, and characterized by XRD, FTIR and Size Distribution. The XRD showed that 600-800°C, the major phase is the tricalcium phosphate, 900-1100°C, there is a phase calcium pyrophosphate. And at 1200 and 1350 ° C, there is a phase monetite. The infrared spectrum showed the characteristic vibrations of calcium phosphates in all conditions studied. It was observed from the results of FTIR presence of bands of the P-OH group and HPO{sub 4}{sup 2-}, PO{sub 4}{sup 3}, for all temperatures studied. The highest average size of agglomerates of 108.05 mM was observed for the temperature of 1100 ° C. (author)

  8. Tailored temperature window of CuO{sub x}/WO{sub x}–ZrO{sub 2} for NO{sub x} reduction via adjusting the calcination temperature of WO{sub x}–ZrO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Si, Zhichun, E-mail: si.zhichun@sz.tsinghua.edu.cn [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Wu, Xiaodong [State Key Laboratory of New Ceramics and Fine Process, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Yangtze Delta Region Institute of Tsinghua University, Zhejiang 314000 (China); Weng, Duan, E-mail: duanweng@tsinghua.edu.cn [State Key Laboratory of New Ceramics and Fine Process, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Ma, Ziran; Ma, Jing [State Key Laboratory of New Ceramics and Fine Process, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-02-15

    WO{sub x}–ZrO{sub 2} support was calcined at various temperatures for obtaining controllable activity of copper catalysts for NO{sub x} reduction by ammonia. The temperature window of copper catalyst for over 80% NO{sub x} conversion shifts from 180–300 to 230–350 °C by elevating the calcination temperature of WO{sub x}–ZrO{sub 2} support from 500 to 600 °C, due to the increased Brønsted acidity and reduced structure and electronic interactions between copper oxides and tungsten oxides arising from the polymerization of WO{sub x} clusters on surface of support. Calcining WO{sub x}–ZrO{sub 2} support at 700 °C leads to the reduced redox property of copper oxides on the Cu–O–W interface and the formation of bulk-like CuO, results in a low activity of catalyst. - Graphical abstract: The temperature window of catalyst for over 80% NO{sub x} conversion shifts from 180-300 °C to 230–350 °C by elevating the calcination temperature of WO{sub x}–ZrO{sub 2} support from 500 °C to 600 °C. Highlights: ► The temperature window of catalyst is tailored by calcining the support. ► The mechanisms of tailoring the temperature window of catalyst are discussed. ► The polymerization of WO{sub x} leads to the increased Brønsted acidity of catalysts. ► The CuO{sub x}/WO{sub x} interactions are reduced by elevating calcination temperature of support.

  9. Volatility of ruthenium during vitrification operations on fission products. part 1. nitric solutions distillation concentrates calcination. part 2. fixation on a steel tube. decomposition of the peroxide; Volatilite du ruthenium au cours des operations de vitrification des produits de fission. 1. partie distillation des solutions nitriques calcination des concentrats 2. partie fixation sur un tube d'acier decomposition du peroxyde

    Energy Technology Data Exchange (ETDEWEB)

    Ortins de Bettencourt, A; Jouan, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    During vitrification of fission product solutions, a high percentage of the ruthenium initially present in these solutions in the form of nitrosyl-ruthenium nitrates is volatilized with the production of the peroxide which itself is decomposed to ruthenium dioxide. The aim of this work has been to study the volatility of the ruthenium during the vitrification processes. During the distillation of the nitric solutions, we have studied in particular the influence on the volatility of the temperature , of the chemical form in which the ruthenium is introduced, of the bubbling of a gas through the solution, of the nitric concentration and of the nitrate concentration. During the calcination, we have observed the influence of the temperature, of the time, of the flow rate and of the nature of the carrier gas, as well as of the action of the ruthenium bi-oxide and the iron oxide on the volatility of the ruthenium. Part 2. This report deals with the study of the thermal decomposition of ruthenium peroxide, RuO{sub 4}, and its deposition on steel tubing. After a brief bibliographic review of the various properties of this substance, a study is made, in the first part, of its deposition on a steel tube. In order to do this, we pass a gas current containing RuO{sub 4} marked with {sup 106}Ru through a stainless steel tube subjected to a temperature gradient which decreases in the direction of the gas flow. The temperature at which RuO{sub 4} is deposited or is fixed on the tube is determined and the influence of the flow rate on this deposit is studied. In the second part, an attempt has been made to study by a static method the kinetics of the decomposition reaction of ruthenium peroxide to give the dioxide: RuO{sub 4} {yields} RuO{sub 2} + O{sub 2}. To do this, we have tried to introduce gaseous RuO{sub 4} into a container placed in an electric oven, and to follow the reaction by {gamma} counting. (author) [French] Au cours de la vitrification des solutions de produits de

  10. Volatility of ruthenium during vitrification operations on fission products. part 1. nitric solutions distillation concentrates calcination. part 2. fixation on a steel tube. decomposition of the peroxide; Volatilite du ruthenium au cours des operations de vitrification des produits de fission. 1. partie distillation des solutions nitriques calcination des concentrats 2. partie fixation sur un tube d'acier decomposition du peroxyde

    Energy Technology Data Exchange (ETDEWEB)

    Ortins de Bettencourt, A.; Jouan, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    During vitrification of fission product solutions, a high percentage of the ruthenium initially present in these solutions in the form of nitrosyl-ruthenium nitrates is volatilized with the production of the peroxide which itself is decomposed to ruthenium dioxide. The aim of this work has been to study the volatility of the ruthenium during the vitrification processes. During the distillation of the nitric solutions, we have studied in particular the influence on the volatility of the temperature , of the chemical form in which the ruthenium is introduced, of the bubbling of a gas through the solution, of the nitric concentration and of the nitrate concentration. During the calcination, we have observed the influence of the temperature, of the time, of the flow rate and of the nature of the carrier gas, as well as of the action of the ruthenium bi-oxide and the iron oxide on the volatility of the ruthenium. Part 2. This report deals with the study of the thermal decomposition of ruthenium peroxide, RuO{sub 4}, and its deposition on steel tubing. After a brief bibliographic review of the various properties of this substance, a study is made, in the first part, of its deposition on a steel tube. In order to do this, we pass a gas current containing RuO{sub 4} marked with {sup 106}Ru through a stainless steel tube subjected to a temperature gradient which decreases in the direction of the gas flow. The temperature at which RuO{sub 4} is deposited or is fixed on the tube is determined and the influence of the flow rate on this deposit is studied. In the second part, an attempt has been made to study by a static method the kinetics of the decomposition reaction of ruthenium peroxide to give the dioxide: RuO{sub 4} {yields} RuO{sub 2} + O{sub 2}. To do this, we have tried to introduce gaseous RuO{sub 4} into a container placed in an electric oven, and to follow the reaction by {gamma} counting. (author) [French] Au cours de la vitrification des solutions de produits de

  11. Study of the behavior of aggregate of calcined clay for use in permeable pavements for the city of Manaus; Estudo do comportamento de agregado sintetico de argila calcinada para uso em pavimentos permeaveis para a cidade de Manaus

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.S.; Vilela, P.A.T.; Araujo, V.S., E-mail: oliveirasmichelle@gmail.com [Universidade do Estado do Amazonas (UEAM), AM (Brazil)

    2016-07-01

    Research on the production of ceramic aggregates and their use in paving in the country began in the 80’s in the search for an alternative material that could replace the pebble or crushed stone, studied the clay, considered an abundant mineral resource by virtue of being the predominant soil in this region and which were made synthetic calcinated clay aggregates (ASAC), for their application in permeable paving concrete motivated by the lack of permeable areas. The study consists of the characterization of materials for manufacture of concrete slabs permeable and the assessment of the effects of synthetic aggregate on its properties in fresh and hardened state. The ceramic bodies were subjected to tests of X-ray diffraction, determination of chemical composition and plasticity. The results indicate that the use of synthetic clusters is a viable alternative for the production of porous concrete. (author)

  12. The Effect of Process Condition and SiO2 as Catalyst for the Density and the Resistivity of the Calcine Coke and Tar Pitch Mixed Pellet as 900 oC Baking Product

    International Nuclear Information System (INIS)

    Tundjung lndrati Y; Imam Dahroni; Kasilani Noor Sayekti

    2002-01-01

    The experiment of the baking condition effect and SiO 2 as catalyst have been done. Graphite turbo static be produced by baking of the mixed pellet ( Calcine Coke, Tar Pitch (32%) and SiO 2 as catalyst). The baking have been done on the inert atmospherics (argon : 2 l/hour) and the heating rate 10 o C/minute. The baking condition and catalyst was affected for density and resistivity. There was little bit density change with densification phenomena. The graphite resistivity was more decrease with the increasing of heating and the longer baking time. The baking condition for produce turbo static graphite with resistivity 2100 Ωμm and density 1.4 gram/cm 3 was 900 o C, 3 hours for baking time and optimal adding catalyst SiO 2 0.5 %. (author)

  13. An ingenious strategy of preparing TiO2/g-C3N4 heterojunction photocatalyst: In situ growth of TiO2 nanocrystals on g-C3N4 nanosheets via impregnation-calcination method

    Science.gov (United States)

    Zhang, Guanghui; Zhang, Tianyong; Li, Bin; Jiang, Shuang; Zhang, Xia; Hai, Li; Chen, Xingwei; Wu, Wubin

    2018-03-01

    An ingenious method was employed to design and fabricate the TiO2/g-C3N4 heterojunction photocatalysts in this study. The thermal oxidation etching of g-C3N4 nanosheets and the in situ growth of TiO2 nanocrystal on the surface of g-C3N4 nanosheets were completed simultaneously by the calcination process. The g-C3N4 nanosheets played a crucial role in regulating and assembling the structures and morphologies of TiO2. Furthermore, the thickness and content of g-C3N4, and the crystallinity of TiO2 in TiO2/g-C3N4 composites could be regulated and controlled by the calcination temperature. Among the resultant TiO2/g-C3N4 samples, the TiO2/g-C3N4 sample with 41.6 wt% g-C3N4 exhibited the highest photocatalytic activity. It could degrade almost all MO molecules under visible light irradiation within 3 h. Moreover, it displayed higher visible light photocatalytic performance for degrading MO solution than pure g-C3N4 and D-TiO2. The synergistic effect between TiO2 and g-C3N4 makes significant contributions to the enhancement of the visible light photocatalytic activity. In addition, the favorable photocatalytic performance of TiO2/g-C3N4 nanocomposites is also attributed to the porous structures and uniform morphologies, and large surface area. Furthermore, the resultant TiO2/g-C3N4 exhibits excellent photocatalytic stability. Radical trapping experiments indicated that rad O2- and h+ were the main reactive species during the photodegradation process under visible light irradiation. Hopefully, the results can offer new design and strategy for preparing other g-C3N4-based nanocomposites for environmental and energy applications.

  14. Single and multi-component adsorption of salicylic acid, clofibric acid, carbamazepine and caffeine from water onto transition metal modified and partially calcined inorganic-organic pillared clay fixed beds.

    Science.gov (United States)

    Cabrera-Lafaurie, Wilman A; Román, Félix R; Hernández-Maldonado, Arturo J

    2015-01-23

    Fixed-beds of transition metal (Co(2+), Ni(2+) or Cu(2+)) inorganic-organic pillared clays (IOCs) were prepared to study single- and multi-component non-equilibrium adsorption of a set of pharmaceutical and personal care products (PPCPs: salicylic acid, clofibric acid, carbamazepine and caffeine) from water. Adsorption capacities for single components revealed that the copper(II) IOCs have better affinity toward salicylic and clofibric acid. However, multi-component adsorption tests showed a considerable decrease in adsorption capacity for the acids and an unusual selectivity toward carbamazepine depending on the transition metal. This was attributed to a combination of competition between PPCPs for adsorption sites, adsorbate-adsorbate interactions, and plausible pore blocking caused by carbamazepine. The cobalt(II) IOC bed that was partially calcined to fractionate the surfactant moiety showcased the best selectivity toward caffeine, even during multi-component adsorption. This was due to a combination of a mildly hydrophobic surface and interaction between the PPCP and cobalt(II). In general, the tests suggest that these IOCs may be a potential solution for the removal of PPCPs if employed in a layered-bed configuration, to take care of families of adsorbates in a sequence that would produce sharpened concentration wavefronts. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Effect of calcination temperature on microstructure and magnetic properties of Ni{sub 0.5}Zn{sub 0.25}Cu{sub 0.25} Fe{sub 2}O{sub 4} nanoparticles synthesized by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Pransisco, Prengki, E-mail: prengkipransisco@gmail.com, E-mail: afza@petronas.com.my; Shafie, Afza, E-mail: prengkipransisco@gmail.com, E-mail: afza@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Guan, Beh Hoe, E-mail: beh.hoeguan@petronas.com.my

    2014-10-24

    This paper examines the effect of calcination process on the structural and magnetic properties material nanostructure composite of Ni{sub 0Ð}œ‡{sub 5}Zn{sub 0Ð}œ‡{sub 25}Cu{sub 0.25} Fe{sub 2}O{sub 4} ferrites. The samples were successfully prepared by sol-gel method at different calcination temperature, which are 600°C, 700°C, 800°C and 900°C. Morphological investigation, average crystallite size and microstructure of the material were examined by using X-ray diffraction (XRD) and confirmed by high resolution transmission electron microscope (HRTEM) and field emission scanning electron microscope (FESEM). The effects of calcination temperature on the magnetic properties were calculated by using vibrating sample magnetometer (VSM). The XRD result shows single-phase cubic spinel structure with interval average size 5.9-38 nm, and grain size microstructure of the material was increasing with temperature increases. The highest magnetization saturation was reached at a temperature 800°C with value 53.89 emu/g, and the value coercive force (Hc) was inversely with the grain size.

  16. Efeito da argila calcinada sobre a durabilidade de argamassas reforçadas com fibras curtas de sisal Effect of calcined clay on aging of sisal short fiber reinforced mortar

    Directory of Open Access Journals (Sweden)

    João de Farias Filho

    2010-10-01

    Full Text Available O interesse pelo uso de fibras vegetais como reforço de matrizes, à base de cimento, tem crescido em todo o mundo nos últimos anos, sendo limitado pela baixa durabilidade das fibras no meio alcalino. Com o tempo, as fibras podem mineralizar devido à migração de hidróxido de cálcio (CH da matriz para o lúmen e paredes das fibro-células. Procurou-se consumir, no presente estudo, o CH livre utilizando-se resíduo de tijolo moído e metacaulinita em substituição parcial, de 20 e 40% em peso, do cimento portland. Compósitos com fibras de sisal e matrizes cimento-pozolana foram submetidos a ensaios de resistência a flexão, após 28 dias de cura em água, 135 e 180 dias de envelhecimento natural e após 94 ciclos de molhagem e secagem. Os resultados indicaram que é possível consumir todo o CH da matriz, o que resultou na manutenção da tenacidade inicial do compósito e no aumento da sua resistência a flexão após exposição natural ou ciclos de molhagem e secagem.In the last few years a growing interest in the use of sisal fibers as reinforcement in cement based composites has been observed. However, the main concern for its use is related with the durability of the fibers in the alkaline water of concrete as they can mineralize due to the migration of calcium hydroxide to the fiber lumen and cell walls. In this study, the alkalinity of the matrix was reduced using metakaolin and crushed waste calcined clay bricks as cement replacement. The percentage of cement replacement ranged from 20 to 40% on weight basis. Flexural tests were carried out in the composites after 28 days of cure in water, 135 and 180 days of ageing in the open air and after 94 cycles of wetting and drying. These results indicated that the mixture with cement replacement consumed all calcium hydroxide and kept the toughness over time.

  17. Potencialidades da metacaolinita e do tijolo queimado moído como substitutos parciais do cimento Portland Potentialities of metakaolin and crushed waste calcined clay brick as partial replacement of Portland cement

    Directory of Open Access Journals (Sweden)

    João de Farias Filho

    2000-12-01

    Full Text Available Avalia-se, neste trabalho, a potencialidade do uso da metacaolinita e dos resíduos de produção de tijolos cerâmicos queimados finamente moídos, como substitutos parciais do cimento Portland. Os materiais foram caracterizados física, química e mineralogicamente, além de determinado o índice de atividade pozolânica com cimento Portland. A evolução da resistência a compressão e a flexão das argamassas foi avaliada até as idades de, respectivamente, 365 e 208 dias. As porcentagens de substituição do cimento Portland, em peso, pelos materiais pozolânicos, variaram de 20 a 50%, enquanto o fator água/cimento variou de 0,37 a 0,45. Os resultados obtidos indicaram que a metacaolinita e o tijolo moído queimado possuem elevada atividade pozolânica e que a resistência a compressão, aos 28 dias, das argamassas mistas, foi superior à das argamassas de cimento Portland para os níveis de substituição e fatores água/cimento estudados. Um modelo matemático para predição da resistência à compressão das argamassas mistas é proposto com base em um desenho fatorial de experimentos.This paper evaluates the potentiality of metakaolin and crushed waste fired clay brick as cement replacement materials. They were characterised physically, chemically and mineralogically and their activity with Portland cement determined. The influence of the partial replacement of Portland cement on the development of compressive and flexural strength was evaluated until the age of, respectively, 365 and 208 days. The percentage of cement replacement, in weight, ranged from 20 to 50%, whereas the water/cement ratio ranged from 0.37 to 0.45. The results obtained show that the metakaolin and crushed calcined clay brick presented a good pozolanic activity and that the compressive strength of the blended mortars after 28 days of cure was higher than that observed for the reference Portland cement for all levels of cement replacement and water/cement ratio. A

  18. Radiant-Heat Spray Calcination Studies; Calcination par Pulverisation et Chauffage Radiant; 0418 0421 0421 041b 0415 0414 041e 0412 0410 041d 0418 042f 041d 0410 041a 0410 041b 042c 0426 0418 041d 0410 0422 041e 0420 0410 0425 0424 041e 0420 0421 0423 041d 041e 0427 041d 041e 0413 041e 0422 0418 041f 0410 0421 041d 0410 0413 0420 0415 0412 0410 041d 0418 0415 041c 0422 0415 041f 041b 041e 0412 042b 041c 0418 0417 041b 0423 0427 0415 041d 0418 0415 041c ; Estudios de Calcinacion por Pulverizacion y Calentamiento Radiante

    Energy Technology Data Exchange (ETDEWEB)

    Allemann, R. T.; Moore, R. L.; Upson, U. L. [Hanford Laboratories General Electric Co., Richland, WA (United States)

    1963-02-15

    The radiant-heat spray calcination process for conversion of liquid wastes to solids is described and the design of a one-gallon-per-hour spray calcination unit coupled with a small melt pot, capable of being run separately as a pot calciner, is discussed. The units were designed to test the feasibility of the calcination process with actual Purex plant waste in terms of the process as a unit operation, off-gas treatment, fission-product behaviour, condensate and calcined waste characteristics. The entire system was made to fit into an available 7-1/2 ft x 15 ft x 15 ft tall, manipulator-equipped, shielded cell which is also described. Included in the design discussion are: the resistance heating of the spray calciner column, thermal insulation of the column, spray nozzle, method of nozzle replacement, induction heating of the melt pot, radioactivity scanner for the pot, off-gas processing system including condenser, scrubber and filters, off-gas sampling device, liquid sampling device, wash-down system, feed system, instrumentation and control methods. The experience gained in operating the calciners and associated equipment is discussed. Experimental results presented show the effectiveness of off-gas decontamination and behaviour of gross chemical constituents and some specific fission products. (author) [French] Les auteurs etudient le procede de calcination par pulverisation et chauffage radiant utilise pour transformer les dechets liquides en solides; ils decrivent notamment une installation de calcination par pulverisation (d'une capacite de 1 gallon par heure) accouplee a un petit creuset que l'on peut utiliser separement comme creuset de calcination. Cet ensemble- a ete concu pour etudier la possibilite de calciner des dechets reels resultant du traitement Purex, en tenant compte des facteurs suivants: operations dans un seul appareil, traitement des gaz d'echappement, comportement des produits de fission, caracteristiques du condense et des dechets

  19. Potencialidades de um caulim calcinado como material de substituição parcial do cimento portland em argamassas Potentialities of a calcined kaolin as material of partial replacement of portland cement in mortars

    Directory of Open Access Journals (Sweden)

    Marilia P. de Oliveira

    2006-06-01

    Full Text Available A utilização de argilas calcinadas na forma de metacaulinita, como material pozolânico para argamassas e concretos, tem recebido atenção considerável nos últimos anos. Este trabalho objetivou avaliar o desempenho mecânico de argamassas, nas quais foi utilizado um caulim calcinado proveniente do Estado da Paraíba, como material de substituição parcial do cimento Portland. Utilizaram-se duas finuras do caulim: passando nas peneiras ABNT 200 (0,074 mm e 325 (0,044 mm e calcinados nas temperaturas de 700, 800 e 900 ºC pelo tempo de 2 h. As amostras foram caracterizadas através de análise química, análise térmica diferencial, difração de raios-X e área específica. Obteve-se o índice de atividade pozolânica com a cal e o cimento Portland. O percentual de substituição adotado foi de 0, 10, 20, 30 e 40%. A relação aglomerante: areia foi de 1:1,5 e a relação água/aglomerante fixada igual 0,4. O efeito da substituição parcial do cimento na argamassa foi avaliado através da resistência à compressão simples, nas idades de 7, 28 e 90 dias. As argamassas estudadas apresentaram resistência superior em relação à da referência, até o nível de 30% de substituição.The use of burnt clays, in the metakaolin form, as pozzolanic material for mortars and concretes has received a remarkable attention in the last years. This paper aimed to evaluate the mechanical property of mortars, in which a calcined kaolin originating from the State of Paraiba, was used as partial cement replacement material. Two finess of the kaolin were used: ABNT 200 (0.074 mm and 325 (0.044 mm and burnt at temperatures of 700, 800 and 900 ºC for a period of 2 h. Both materials were characterized by chemical analysis, differential thermal analysis, X-ray diffraction, specific area tests. The pozolanic activity index was obtanied using lime and cement Portland. The amounts of replacement were 10, 20, 30 and 40%, besides the reference mortar. The binder

  20. Production of BaAl{sub 2}O{sub 4} doped with Eu{sup 3+} in low temperature: research of the influence of the synthesis route, temperature and calcination time in the optical properties; Producao do BaAl{sub 2}O{sub 4} dopado com Eu{sup 3+} em baixa temperatura: investigacao da influencia da rota de sintese, temperatura e tempo de calcinacao nas propriedades opticas

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Manasses Almeida

    2017-07-01

    In this work, the synthesis condition (complexing agent and temperature and time of calcination) were studied aiming to produce BaAl{sub 2}O{sub 4} samples in the ferroelectric hexagonal phase. Pure and Eu{sup 3+} - doped samples were produced and its luminescent properties were investigated. BaAl{sub 2}O{sub 4} was prepared using several thermal treatment conditions, via an alternative sol-gel route, using coconut water or PVA as the complexing agents. The sample production at 600 °C/5h is quite interesting, since to date the lowest calcination temperatures found in the literature was 650 ° C using reagents with high degree of toxicity DTA / TG measurements indicated a possible start of the crystallization of the material at approximately 600 ° C, and the X-ray powder diffraction (XRD) confirm the formation of the desired phase of the calcined barium aluminate at that temperature. The results of the Rietveld refinements showed the occurrence of secondary phase in the samples produced at 600 ° C / 5h, presenting 5% of phase Ba(NO{sub 3}){sub 2}, while single phase was found for samples calcined at 1200 ° C for 2 and 5h. Analysis of the diffractogram by the Scherrer equation showed smaller crystallite size for samples calcified at 600 °C/5h, but apparently with a lower degree of crystallinity than the sample prepared at 1200 ° C/ 2 and 5h. The photoluminescence measurements showed that the emission spectra of the samples have great dependence on the times, temperatures and complexing agents used. In particular, samples calcined at 600 ° C have very different characteristics with regard to the probabilities of emissions associated with Eu{sup 3+} when compared with samples produced at higher temperatures. Differences observed in the spectra of samples produced via different complexing agents are possibly due to defects created in the materials by impurities present in the coconut water. Samples produced using PVA present sites with higher symmetry, which was

  1. Continuous Calcination of High-Level Radioactive Wastes by Means of a Rotary-Ball Kiln; Calcination Continue de Dechets de Haute Activite dans un Four Rotatif a Billes; 041d 0415 041f 0420 0415 0420 042b 0412 041d 041e 0415 041a 0410 041b 042c 0426 0418 041d 0418 0420 041e 0412 0410 041d 0418 0415 0412 042b 0421 041e 041a 041e 0410 041a 0422 0418 0412 041d 042b 0425 041e 0422 0425 041e 0414 041e 0412 0412 041e 0412 0420 0410 0429 0410 042e 0429 0415 0419 0421 042f 0428 0410 0420 041e 0412 041e 0419 041f 0415 0427 0418 ; Calcinacion Continua de Desechos de Elevada Radiactividad en un Horno de Bolas Rotatorio

    Energy Technology Data Exchange (ETDEWEB)

    Regan, W. H.; Hatch, L. P.; Domish, R. F. [Brookhaven National Laboratory, Upton, Long Island, NY (United States)

    1963-02-15

    The calcination of high-level, high salt content, aqueous wastes to convert the bulk salts to stable solid form offers important advantages in ultimate waste disposal, namely, major reduction in waste volume and general simplification of long-range waste-storage problems. Among the types of wastes commonly considered for calcination are those produced in the aqueous reprocessing of aluminium alloy and zirconium-alloy fuels and in the reprocessing of fuels clad with stainless steel or having stainless-steel matrices. Decomposition of the bulk salts thus involved, namely, aluminium nitrate, zirconium fluoride and ferric nitrate to their respective oxides introduces a number of serious operations problems many of which stem from the formation of highly radioactive solids with substantial proportions in the small, or low micron, range. One promising type of calciner, which is under development at the Brookhaven National Laboratory operates on the principle of a rotary-ball kiln. Basically, the unit consists of a slowly rotating horizontal tube or kiln externally heated by means of electric resistance heaters. Feed is introduced into the kiln by means of a distribution nozzle and falls on a hot, shallow bed of metal balls, which aid in heat transfer and prevent the formation of large agglomerates during calcination. The calcined solids overflow from the discharge end of the kiln into a powder receiver. The calciner is designed for continuous operation, to give good transfer of heat to the interior of the kiln and to reduce problems of controlling radioactive dust to a bare minimum. Since no non-condensable gases are added to the system, excellent dust control is accomplished by direct condensation of off-gases followed by passing the small non-condensable portion through a scrubber and absolute filter. An engineering scale calciner has been constructed at Brookhaven and is at present being used to carry out equipment and process development studies. The rotary kiln is 8

  2. Calcination of Radioactive Waste in Molten Sulphur; Calcination de Dechets Radioactifs dans le Soufre Fondu; 041a 0410 041b 042c 0426 0418 041d 0418 0420 041e 0412 0410 041d 0418 0415 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 042b 0425 041e 0422 0425 041e 0414 041e 0412 0412 0420 0410 0421 041f 041b 0410 0412 041b 0415 041d 041d 041e 0419 0421 0415 0420 0415 ; Calcinacion de Desechos Radiactivos en Azufre Fundido

    Energy Technology Data Exchange (ETDEWEB)

    Winsche, W. E.; Davis, Jr., M. W.; Goodlett, Jr., C. B.; Occhipinti, E. S.; Webster, D. S. [E.I. Du Pont de Nemours and Co., Aiken, SC (United States)

    1963-02-15

    The Savannah River Laboratory is developing a novel process based on the unique properties of sulphur for converting radioactive wastes to a solid form of low solubility for ''ultimate'' disposal. In this process the aqueous acidic wastes are reacted with molten sulphur at 150 Degree-Sign C so that the water and volatile acids are driven off and the chemical compounds present in the waste are calcined and/or chemically reduced. The resulting sulphur-waste slurry is then heated at 400 to 444 Degree-Sign C for from 1 to 5 hr to drive off sulphuric acid and residual water and further calcine and/or reduce the chemical compounds in the sulphur-waste slurry. In these steps the molten sulphur serves as a heat-transfer medium, prevents the entrainment of the radioactive solids in the steam and reaction gases and eliminates the volatilization of radioactive ruthenium by preventing the formation of the tetroxide. Laboratory scale runs with concentrated high activity waste as feed (1.3 x 10{sup 9} {gamma} c/(min)(ml), 2.0M Al(N0{sub 3}){sub 3}, and 1.5M HNO{sub 3}) have shown that only one part in approximately 100 000 parts of the activity in the feed is carried overhead in the off-gas in these process steps. After the completion of the high-temperature treatment, the sulphur-waste slurry is cooled to 120-150 Degree-Sign C and transferred as a liquid to the final containment system where it is allowed to solidify. Although it is our intent to protect the containment system against the action of water, the resistance of the solidified sulphur- waste slurry to the action of water has been used as a measure of the effectiveness of this process. Small cylinders of the solidified slurry have been prepared from simulated wastes containing Al (NO{sub 3}){sub 3} or dissolved stainless-steel nitrates with tracer levels of Sr and Cs, and for concentrated high-activity waste containing Al(NO{sub 3}s){sub 3}. These cylinders have been exposed to water over extended periods of time

  3. Design of a Hot Pilot-Plant Facility for Demonstrating the Pot-Calcination Process; Installation Pilote de Haute Activite pour la Demonstration du Procede De Calcination En Pot; 041a 041e 041d 0421 0422 0420 0423 041a 0426 0418 042f 0413 041e 0420 042f 0427 0415 0419 041e 041f 042b 0422 041d 041e 0419 0423 0421 0422 0410 041d 041e 0412 041a 0418 0414 041b 042f 0414 0415 041c 041e 041d 0421 0422 0420 0410 0426 0418 0418 041f 0420 041e 0426 0415 0421 0421 0410 041a 0410 041b 042c 0426 0418 041d 0418 0420 041e 0412 0410 041d 0418 042f 0412 0422 0418 0413 041b 042f 0425 ; Construccion de una Instalacion Experimental de Evevada Actividad para el Proceso de Calcinacion en Crisol

    Energy Technology Data Exchange (ETDEWEB)

    Buckham, J. A. [Phillips Petroleum Company, Idaho Chemical Processing Plant, Idaho Falls, ID (United States)

    1963-02-15

    A facility has been designed for demonstrating the pot-calcination process with full-level wastes from processing aluminium alloy fuels, from Darex or electrolytic processing of stainless-steel fuels and from Purex processes. This facility will also permit the determination of procedures require a for economical production of low-porosity, relatively non-leachable materials by the addition of suitable reagents to the wastes fed to the calciner. The pot-calcination process, consisting of concentration by evaporation and thermal decomposition in situ in pots which also serve as the final disposal containers, was evolved at the Oak Ridge National Laboratory and developed there in radioactive bench-scale and non-radioactive pilot-plant scale studies. The radioactive demonstration unit will permit identification and solution of operational and control problems connected with the calciner or its closely associated feed preparation and condensate clean-up systems; many of these problems are associated with self-heating and the volatility of fission products. This unit will permit determination of pot loading and density, leachability, melting point, volatile material content, heat release and thermal conductivity of the calcine. Also to be determined are transient calcine temperature distributions, fission-product behaviour during calcination, de-entrainment obtained in the various parts of the system, decontamination achieved on all liquid and gaseous effluent streams, need for venting of stored pots, optimum means of remotely sealing the pots, and methods required for production of a minimum volume of non-condensible off-gas. This facility will employ nominal full-scale pots 8 and 12 inches in diameter and 8 feet long. A unique evaporator design was evolved to permit operation either with close-coupled continuous feed preparation or with bath feed preparation. Provisions were made to circumvent possible explosions due to organic material in feed solutions and other

  4. Synthesis, characterization and comparison of Li{sub 1,05}M{sub 0,02}Mn{sub 1,98}O{sub 4} (M = Al{sup 3+} or + Ga{sup 3+}) obtained by calcination in muffle and microwave; Sintese, caracterizacao e comparacao dos Li{sub 1,05}Mn{sub 1,98}M{sub 0,02}O{sub 4} (M= Al{sup 3+} ou GA{sup 3+}) obtidos por calcinacao em mufla e microondas

    Energy Technology Data Exchange (ETDEWEB)

    Santana, L.K.; Canobre, S.C.; Amaral, F.A., E-mail: fabioamaral@yahoo.com.br [Universidade Federal de Uberlandia (UFU), MG (Brazil). Instituto de Quimica. Laboratorio de Armazenamento de Energia e Tratamento de Efluentes

    2014-07-01

    Due to the economic and environmental importance of using LiMn{sub 2}O{sub 4} as cathode batteries, the goal of this work was to synthesize LiMn{sub 2}O{sub 4} doped and undoped, comparing methods of calcination kiln and microwave. The precursors were obtained by Pechini method. The resulting samples were structurally characterized by XRD, morphology by SEM and area by B.E.T. XRD results were compared to card JCPDS 35-0782 regarding the pure LiMn{sub 2}O{sub 4}. The DRX results indicate that the calcination furnace was more efficient for obtaining doped oxides. However, the use of microwave was effective for rapid attainment of non-doped spinel close to those found for the pure spinel structural features. The surface area values confirm the existence of clusters and particles with nanometric features. Oxides synthesized in both procedures showed small, organized and highly crystalline particles, demonstrating the efficiency of the methodology and Pechini methods of calcination compared. (author)

  5. Fluidization Characteristics of Dolomite and Calcined Dolomite Particles

    Czech Academy of Sciences Publication Activity Database

    Hartman, Miloslav; Trnka, Otakar; Svoboda, Karel

    2000-01-01

    Roč. 55, č. 24 (2000), s. 6269-6274 ISSN 0009-2509 R&D Projects: GA AV ČR IAA4072711; GA ČR GA203/98/0101 Institutional research plan: CEZ:AV0Z4072921 Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.053, year: 2000

  6. Plasma Spraying of Silica-Rich Calcined Clay Shale

    Czech Academy of Sciences Publication Activity Database

    Dubský, Jiří; Chráska, Tomáš; Pala, Zdeněk; Nevrlá, Barbara; Chráska, Pavel

    2014-01-01

    Roč. 23, č. 4 (2014), s. 732-741 ISSN 1059-9630 R&D Projects: GA ČR GAP107/12/1922; GA ČR(CZ) GAP108/12/1872 Institutional support: RVO:61389021 Keywords : clay shale * crystallinity * grain size * mullite * water stabilized plasma * x-ray diffraction Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.344, year: 2014 http://link.springer.com/article/10.1007%2Fs11666-014-0076-3

  7. Crystallinity and shape of crushed calcined coke particles

    International Nuclear Information System (INIS)

    Fecioru, M.; Petrescu, M.; Georgeoni, P.

    1993-01-01

    The particle eccentricity is a very important property of the petroleum coke in determining the anisotropy of the properties of the final graphite and it affects the manner in which its properties change in the specific applications. (orig.)

  8. Crystallinity and shape of crushed calcined coke particles

    Energy Technology Data Exchange (ETDEWEB)

    Fecioru, M. (DACIA Synthetic Diamonds Factory, Bucharest (Romania)); Petrescu, M. (DACIA Synthetic Diamonds Factory, Bucharest (Romania) Polytechnic Inst., Bucharest (Romania)); Georgeoni, P. (DACIA Synthetic Diamonds Factory, Bucharest (Romania))

    1993-11-01

    The particle eccentricity is a very important property of the petroleum coke in determining the anisotropy of the properties of the final graphite and it affects the manner in which its properties change in the specific applications. (orig.).

  9. Modeling of flash calcination process during clay activation

    International Nuclear Information System (INIS)

    Borrajo Perez, Ruben; Gonzalez Bayon, Juan Jose; Sanchez Rodriguez, Andy A.

    2011-01-01

    Pozzolanic activity in some materials can be increased by means of different processes, among them, thermal activation is one of the most promising. The activation process, occurring at high temperatures and velocities produces a material with better characteristics. In the last few years, high reactivity pozzolan during cure's early days has been produced. Temperature is an important parameter in the activation process and as a consequence, the activation units must consider temperature variation to allow the use of different raw materials, each one of them with different characteristics. Considering the high prices of Kaolin in the market, new materials are being tested, the clayey soil, which after a sedimentation process produces a clay that has turned out to be a suitable raw material, when the kinetics of the pozzolanic reaction is considered. Additionally, other material with higher levels of kaolin are being used with good results. This paper is about the modeling of thermal, hydrodynamics and dehydroxilation processes suffering for solids particles exposed to a hot gas stream. The models employed are discussed; the velocity and temperature of particles are obtained as a function of carrier gas parameters. The calculation include the heat losses and finally the model predict the residence time needed for finish the activation process. (author)

  10. Fluidized-bed calciner with combustion nozzle and shroud

    International Nuclear Information System (INIS)

    Wielang, J.A.; Palmer, W.B.; Kerr, W.B.

    1977-01-01

    A nozzle employed as a burner within a fluidized bed is coaxially enclosed within a tubular shroud that extends beyond the nozzle length into the fluidized bed. The open-ended shroud portion beyond the nozzle end provides an antechamber for mixture and combustion of atomized fuel with an oxygen-containing gas. The arrangement provides improved combustion efficiency and excludes bed particles from the high-velocity, high-temperature portions of the flame to reduce particle attrition. 4 claims, 2 figures

  11. Introduction. Aluminium production on electrolytic cells with calcined anodes

    International Nuclear Information System (INIS)

    Galushkin, N.V.

    1995-01-01

    This chapter presents the monograph content, which includes the description of physicochemical processes in aluminium electrolytic cells, and mechanism of electrolytic aluminium obtaining. The short description of aluminium electrolytic cells construction is presented in this book as well.

  12. Efecto de la concentración de SO2 en las reacciones de calcinación y sulfatación de calcáreos en reactores de lecho fluidizado. // Effect of the SO2 concentration in the calcinations and sulfatation reactions in a fluidized bed reactor.

    Directory of Open Access Journals (Sweden)

    J. E. Lindo Samaniego

    2008-01-01

    Full Text Available Fue realizado un estudio sobre el efecto de las concentraciones de SO2 en la absorción por calcáreo en hornos de LechoFluidizado. Para observar la influencia del SO2 en los parámetros de diferentes procesos físicos y químicos fueron creadosambientes para cuatro concentraciones diferentes de SO2 : 500, 1000, 2000 y 4000 ppm. Se utilizaron dos tipos decalcáreos: Dolimitico-DP y el Calcítico-CI. El Lecho Fluidizado Burbujeante utilizado tiene 160 mm de diámetro interno yfue fluidizado con aire a la temperatura de 850 °C, con una concentración de SO2 deseada. Como material del lecho fueutilizada la arena de cuarzo (99,9% con diámetro de 385 μm y de masa aproximadamente 3,0 kg. El calcáreo fueadicionado en dosificación de 50 g con el reactor ya pre-calentado. Las variaciones de las concentraciones de SO2, CO2,CO, O2 y las descargas, fueron monitoreadas continuamente a la salida del ciclón que fue utilizado para la retención de lapartícula fina. Para esos dados se desarrolló un programa en LabView. El modelo matemático escogido posibilitó ladeterminación de la conversión.Palabras claves: Lecho fluidizado, dióxido de azufre, absorción de azufre, calcáreo , reactor de lechofluidizado.___________________________________________________________________________Abstract.A Study of the effect of the concentrations of SO2 in its absorption by limestones in fluidized bed furnaces wasconducted. For the determination of the SO2 influence on the different physical and chemical parameters of process,such as calcinations and sulfatation four different atmospheres were used in the reator with concentrations of SO2 of500, 1000, 2000 and 4000 ppm. Two types of limestones were used: Dolomite-DP and Calcitic-CI. The bench scalebubbling fluidized bed reactor had a 160 mm internal diameter and was fluidized with air at 850 °C containing therequired concentration of SO2. Bed material was quartz sand (99,9% , with 385 μm diameter and approximately

  13. Mechanistic approach for the kinetics of the decomposition of nitrous oxide over calcined hydrotalcites

    Energy Technology Data Exchange (ETDEWEB)

    Dandl, H.; Emig, G. [Lehrstuhl fuer Technische Chemie I, Erlangen (Germany)

    1998-03-27

    A highly active catalyst for the decomposition of N{sub 2}O was prepared by the thermal treatment of CoLaAl-hydrotalcite. For this catalyst the reaction rate was determined at various partial pressures of N{sub 2}O, O{sub 2} and H{sub 2}O in a temperature range from 573K to 823K. The kinetic simulation resulted in a mechanistic model. The energies of activation and rate coefficients are estimated for the main steps of the reaction

  14. Formulation Efforts for Direct Vitrification of INEEL Blend Calcine Waste Simulate: Fiscal Year 2000

    International Nuclear Information System (INIS)

    Crum, Jarrod V; Vienna, John D; Peeler, David K

    2001-01-01

    The TFA uses a systematic process for developing its annual program that draws from the tanks science and technology development needs expressed by the five DOE tank waste sites. TFA's annual program development process is iterative and involves the following steps: Collection of site needs; Needs analysis; Development of technical responses and initial prioritization; Refinement of the program for the next fiscal year; Formulation of the Corporate Review Budget (CRB); Preparation of Program Execution Guidance (PEG) for the next FY Revision of the Multiyear Program Plan (MYPP). This document describes the outcomes of the first phase of this process, from collection of site needs to the initial prioritization of technical activities. The TFA received site needs in October- December 2000. A total of 170 site needs were received, an increase of 30 over the previous year. The needs were analyzed and integrated, where appropriate. Sixty-six distinct technical responses were drafted and prioritized. In addition, seven strategic tasks were approved to compete for available funding in FY 2002 and FY 2003. Draft technical responses were prepared and provided to the TFA Site Representatives and the TFA User Steering Group (USG) for their review and comment. These responses were discussed at a March 15, 2001, meeting where the TFA Management Team established the priority listing in preparation for input to the DOE Office of Science and Technology (OST) budget process. At the time of publication of this document, the TFA continues to finalize technical responses as directed by the TFA Management Team and clarify the intended work scopes for FY 2002 and FY 2003

  15. Effect of calcination conditions of pork bone sludge on behaviour of ...

    Indian Academy of Sciences (India)

    †The Alfred Meissner Higher School of Dental Engineering and Humanities, Sloneczna 2, 43-450 Ustron, Poland .... immersion in SBF depends on structure and composition of .... X-ray diffraction method with the use of Philips X'Pert.

  16. Extraction of magnesium from calcined dolomite ore using hydrochloric acid leaching

    Science.gov (United States)

    Royani, Ahmad; Sulistiyono, Eko; Prasetiyo, Agus Budi; Subagja, Rudi

    2018-05-01

    Magnesium is widely used in varieties industrial sector. Dolomite is one source of magnesium besides seawater. The extraction of magnesium from dolomite ores can be done by leaching process. In this work, the dolomite leaching to extract magnesium by hydrochloric acid was investigated. The leaching experiments were performed in a spherical glass batch reactor having a capacity of 1000 ml. The effects of the stirring speed, acid concentration, reaction temperature and liquid-solid ratio for each reaction time of 1; 2; and 3 h on the Mg leaching have been evaluated. 5 ml of solution sample were collected from the leached solutions, then it was filtered prior to analysis by ICP OES. The experimental results show that the magnesium extraction increases along with the increase of acid concentration, liquid-solid ratio and temperature. The optimum conditions for magnesium extraction were achieved at temperature 75 °C, extraction time 3 h, the HCl concentration of 2 M, the liquid-solid ratio 20 ml/g and stirring speed of 400 rpm. At this condition 98, 82 % of magnesium were extracted from dolomite. The conclusion obtained from this leaching process is that the magnesium can be extracted from dolomite by using hydrochloric acid solutions.

  17. Catalytic Reduction of Nitrous Oxide with Carbon Monoxide over Calcined Co–Mn–Al Hydrotalcite

    Czech Academy of Sciences Publication Activity Database

    Pacultová, K.; Obalová, L.; Kovanda, F.; Jirátová, Květa

    2008-01-01

    Roč. 137, 2-4 (2008), s. 358-389 ISSN 0920-5861 R&D Projects: GA ČR(CZ) GA106/05/0366 Institutional research plan: CEZ:AV0Z40720504 Keywords : nitrous oxide * carbon monoxide * mixed oxide catalysts Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.004, year: 2008