WorldWideScience

Sample records for alkaline coal ash

  1. Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash

    International Nuclear Information System (INIS)

    Highlights: ? Incinerator fly ash (IFA) is added to an alkali activated coal fly ash (CFA) matrix. ? Means of stabilizing the incinerator ash for use in construction applications. ? Concrete made from IFA, CFA and IFA-CFA mixes was chemically characterized. ? Environmentally friendly solution to IFA disposal by reducing its toxicity levels. - Abstract: Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA’s Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson’s ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases even below the reporting limit. The leachable Chromium was reduced from 0.153 down to 0.0045 mg/L, Arsenic from 0.256 down to 0.132 mg/L, Selenium from 1.05 down to 0.29 mg/L, Silver from 0.011 down to .001 mg/L, Barium from 2.06 down to 0.314 mg/L and Mercury from 0.007 down to 0.001 mg/L. Although the leachable Cd exhibited an increase from 0.49 up to 0.805 mg/L and Pd from 0.002 up to 0.029 mg/L, these were well below the maximum limits of 1.00 and 5.00 mg/L, respectively.

  2. Environmental risks of farmed and barren alkaline coal ash landfills in Tuzla, Bosnia and Herzegovina

    International Nuclear Information System (INIS)

    The disposal of coal combustion residues (CCR) has led to a significant consumption of land in the West Balkan region. In Tuzla (Bosnia and Herzegovina) we studied previously soil-covered (farmed) and barren CCR landfills including management practises, field ageing of CCR and the transfer of trace elements into crops, wild plants and wastewaters. Soil tillage resulted in mixing of cover soil with CCR. Medicago sativa showed very low Cu:Mo ratios (1.25) which may cause hypocuprosis in ruminants. Total loads of inorganic pollutants in the CCR transport water, but not pH (?12), were below regulatory limits of most EU countries. Arsenic concentrations in CCR transport water were -1 whereas reductive conditions in an abandoned landfill significantly enhanced concentrations in leachates (44 ?g l-1). The opposite pattern was found for Cr likely due to large initial leaching of CrVI. Public use of landfills, including farming, should be based on a prior risk assessment due to the heterogeneity of CCR. - Uncontrolled farming and tillage of previously soil-covered coal ash landfills resulted in exposure of ash on the surface

  3. RECLAMATION OF ALKALINE ASH PILES

    Science.gov (United States)

    The objective of the study was to develop methods for reclaiming ash disposal piles for the ultimate use as agricultural or forest lands. The ashes studied were strongly alkaline and contained considerable amounts of salts and toxic boron. The ashes were produced from burning bit...

  4. Environmental risks of farmed and barren alkaline coal ash landfills in Tuzla, Bosnia and Herzegovina

    Energy Technology Data Exchange (ETDEWEB)

    Dellantonio, A.; Fitz, W.J.; Custovic, H.; Repmann, F.; Schneider, B.U.; Grunewald, H.; Gruber, V.; Zgorelec, Z.; Zerem, N.; Carter, C.; Markovic, M.; Puschenreiter, M.; Wenzel, W.W. [University for Natural Resources & Applied Life Science, Vienna (Austria)

    2008-06-15

    The disposal of coal combustion residues (CCR) has led to a significant consumption of land in the West Balkan region. In Tuzla (Bosnia and Herzegovina) we studied previously soil-covered (farmed) and barren CCR landfills including management practises, field ageing of CCR and the transfer of trace elements into crops, wild plants and wastewaters. Soil tillage resulted in mixing of cover soil with CCR. Medicago sativa showed very low Cu:Mo ratios (1.25) which may cause hypocuprosis in ruminants. Total loads of inorganic pollutants in the CCR transport water, but not pH (similar to 12), were below regulatory limits of most EU countries. Arsenic concentrations in CCR transport water were < 2 {mu} g l{sup -1} whereas reductive conditions in an abandoned landfill significantly enhanced concentrations in leachates (44 {mu} g l{sup -1}). The opposite pattern was found for Cr likely due to large initial leaching of CrVI. Public use of landfills, including farming, should be based on a prior risk assessment due to the heterogeneity of CCR.

  5. Ash Microspheres for Coal Burning

    International Science & Technology Center (ISTC)

    Estimation of perspectives for ash microspheres production at coal burning thermal power stations , development of methods for their quality certification. Creation of a database for ash microspheres in Russian Federation.

  6. Classification of pulverized coal ash

    International Nuclear Information System (INIS)

    The leachability of fifty different pulverized coal ashes from utilities in the Netherlands, Federal Republic of Germany and Belgium has been studied. Five different ashes were analyzed according to the complete standard leaching test and the results were published earlier. The examination of a wide variety of ashes under a wide range of pH and Liquid to Solid ratio (LS) conditions creates the possibility of identifying systematic trends in fly ash leaching behaviour and to identify the mechanisms controlling release. 16 figs., 2 tabs., 3 app., 25 refs

  7. Coal Ash Contains High Levels of Radioactivity

    Science.gov (United States)

    ... gov/medlineplus/news/fullstory_154590.html Coal Ash Contains High Levels of Radioactivity: Study End product from ... FRIDAY, Sept. 11, 2015 (HealthDay News) -- Coal ash contains levels of radioactivity that raise concern about the ...

  8. Sorption of aqueous phosphorus onto bituminous and lignitous coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Yan Jinying; Kirk, Donald W. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada); Jia, Charles Q. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada)], E-mail: cqjia@chem-eng.toronto.edu; Liu Xinan [College of Chemical Engineering, Chongqing University, Chongqing (China)

    2007-09-05

    Aiming at the development of a phosphorus removal technology for waste water, phosphate (PO{sub 4}{sup 3-}) retention behavior of bituminous and lignitous coal ashes was investigated using a batch reactor. Ash samples, including fresh and weathered fly and bottom ashes, were studied for their sorption isotherms and reversibility. Fly ashes had a much higher phosphate retention capacity (4000-30,000 mg P/kg) than bottom ashes (15-600 mg P/kg). Lignitous coal ashes were more capable of retaining phosphate than bituminous coal ashes. The retention process was largely irreversible, and the irreversibility increased with the increase in the retention capacity. Weathering enlarged the retention capacity of the bituminous bottom ash, but substantially lowered that of the fly ash, likely due to the difference in the weather-induced changes between the fly and bottom ashes. Sorption isotherms of fly ashes were found to be adequately represented by the Langmuir model while those of bottom ashes fitted better to the Freundlich model. Concentrations of Ca{sup 2+} and PO{sub 4}{sup 3-} in the aqueous phase were measured at the end of sorption and desorption experiments, and were compared with solubilities of three calcium phosphate minerals. The aqueous solutions were saturated or super-saturated with respect to tricalcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}) and hydroxyapatite (Ca{sub 5}(PO{sub 4}){sub 3}OH), and slightly under-saturated with respect to amorphous calcium phosphate. It is concluded that precipitation of calcium phosphate is the predominant mechanism for phosphate retention by coal ash under the conditions studied. There is a strong and positive correlation between alkalinity and phosphate sorption capacity. Consequently, acid neutralization capacity (ANC) can be used as an indicator of phosphate sorption capacity of coal ashes.

  9. Promoting effect of various biomass ashes on the steam gasification of low-rank coal

    International Nuclear Information System (INIS)

    Highlights: • Biomass ash was utilized to promote gasification of low rank coal. • Promoting effect of biomass ash highly depended on AAEM content in the ash. • Stability of the ash could be improved by maintaining AAEM amount in the ash. • Different biomass ash could have completely different catalytic activity. - Abstract: Application of biomass ash as a catalyst to improve gasification rate is a promising way for the effective utilization of waste ash as well as for the reduction of cost. Investigation on the catalytic activity of biomass ash to the gasification of low rank coal was performed in details in the present study. Ashes from 3 kinds of biomass, i.e. brown seaweed/BS, eel grass/EG, and rice straw/RS, were separately mixed with coal sample and gasified in a fixed bed downdraft reactor using steam as the gasifying agent. BS and EG ashes enhanced the gas production rate greater than RS ash. Higher catalytic activity of BS or EG ash was mainly attributed to the higher content of alkali and alkaline earth metal (AAEM) and lower content of silica in it. Higher content of silica in the RS ash was identified to have inhibiting effect for the steam gasification of coal. Stable catalytic activity was remained when the amount of AAEM in the regenerated ash was maintained as that of the original one

  10. The handling of coal, ash, limestone & gypsum

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    Eight papers are presented on handling coal, ash, limestone and gypsum, covering: their physical and flow properties; predicting flow problems; design of hoppers, bunkers, bins and silos; handling limestone and gypsum at FGD plants; lessons learned at the Drax power station; quality control of utilization of fly ash; predicting wear lives of pneumatic conveyor pipe bends; and practical problems of transporting PFA. All the papers have been abstracted separately on the IEA Coal Research CD-ROM.

  11. Phase transformation of high alkaline ash residue on the process of sintering and fusion

    Energy Technology Data Exchange (ETDEWEB)

    Yu Hai-miao; Cao Xin-yu; Zhou Jun-hu; Cen Ke-fa [Tongji University, Shanghai (China). College of Mechanical Engineering

    2007-12-15

    Black liquor coal slurry was studied to investigate the phase transformation of high alkaline ash residue on the process of sintering and fusion. After incineration at low temperature, the produced ash particle size falls into the range of 38.5 -74.0 {mu}m. The ash was used to measure the sintering rate. XRD phase analysis and SEM analysis were used to analyze the sintered ash. The results show that highly alkaline ash residues are highly sintered and fusible, which is due to the rich formation of compounds with low fusion temperature such as nosean, hauyne, nepheline, Glauber's salt etc. The phase transforming process of sodium-based compound in the alkaline ash residues is as follows: nosean (Na{sub 8}Al{sub 6}Si{sub 6}O{sub 24}SO{sub 4}), Glauber's salt (Na{sub 2}SO{sub 4}) {yields} nosean, nepheline (Na{sub 6}KAl{sub 7}Si{sub 9}O{sub 32}) {yields} hauyne (K{sub 1.6}Ca{sub 2.4}Na{sub 4.32)(Al{sub 6}Si{sub 6}O{sub 24})(SO{sub 4}){sub 1.52}), nepheline (NaAlSiO{sub 4}). 11 refs., 3 figs., 2 tabs.

  12. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  13. Characterization of sintered coal fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    M. Erol; S. Kucukbayrak; A. Ersoy-Mericboyu [Istanbul Technical University, Istanbul (Turkey). Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty

    2008-06-15

    Can, Catalagzi, Seyitomer and Afsin-Elbistan thermal power plant fly ashes were used to investigate the sintering behavior of fly ashes. For this purpose, coal fly ash samples were sintered to form ceramic materials without the addition of any inorganic additives or organic binders. In sample preparation, 1.5 g of fly ash was mixed in a mortar with water. Fly ash samples were uniaxially pressed at 40 MPa to achieve a reasonable strength. The powder compacts were sintered in air. X-ray diffraction analysis revealed that quartz (SiO{sub 2}), mullite (Al{sub 6}Si{sub 2}O{sub 13}), anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}), gehlenite (Ca{sub 2}Al{sub 2}SiO{sub 7}) and wollastonite (CaSiO{sub 3}) phases occurred in the sintered samples. Scanning electron microscopy investigations were conducted on the sintered coal fly ash samples to investigate the microstructural evolution of the samples. Different crystalline structures were observed in the sintered samples. The sintered samples were obtained having high density, low water adsorption and porosity values. Higher Al{sub 2}O{sub 3} + SiO{sub 2} contents caused to better properties in the sintered materials. 19 refs., 5 figs., 4 tabs.

  14. Use of coal ash for agriculture

    Energy Technology Data Exchange (ETDEWEB)

    Suganuma, H. [CRIEPI, Abiko-shi (Japan). Dept. of Biology

    1996-08-01

    When coal ash reclaimed land is used for agriculture, soil dressing is needed. Depth of soil dressing depend upon the kind of crop root systems. For example, when shallow rooted crops, such as cabbage, spinach and other leaf vegetables, were cultivated, more than 20 cm depth of soil dressing was needed. While deep rooted crops, such as radish, potato and other root vegetables, were cultivated, more than 30 cm depth of soil dressing was needed. When coal ash was used for soil amendment, the growth and development of crops were stimulated, and qualities of products were improved, because the physical, chemical and biological properties of soils were improved by the applications. The amount of coal ash application to the soil was determined based on the soil texture and the species. The soil texture influences the buffer action of soil, while each of the species had different absorption patterns for mineral elements. A potassium silicate fertilizer and a compound fertilizer were developed using coal ash. 16 refs., 1 fig., 3 tabs.

  15. pH-dependent leaching of dump coal ash - retrospective environmental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, A.; Djordjevic, D. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

    2009-07-01

    Trace and major elements in coal ash particles from dump of 'Nikola Tesla A' power plant in Obrenovac near Belgrade (Serbia) can cause pollution, due to leaching by atmospheric and surface waters. In order to assess this leaching potential, dump ash samples were subjected to extraction with solutions of decreasing pH values (8.50, 7.00, 5.50, and 4.00), imitating the reactions of the alkaline ash particles with the possible alkaline, neutral, and acidic (e.g., acid rain) waters. The most recently deposited ash represents the greatest environmental threat, while 'aged' ash, because of permanent leaching on the dump, was shown to have already lost this pollution potential. On the basis of the determined leachability, it was possible to perform an estimation of the acidity of the regional rainfalls in the last decades.

  16. Ash transformation during co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn; Sander, Bo; Junker, Helle

    2007-01-01

    Co-firing straw with coal in pulverized fuel boilers can cause problems related to fly ash utilization, deposit formation, corrosion and SCR catalyst deactivation due to the high contents of Cl and K in the ash. To investigate the interaction between coal and straw ash and the effect of coal quality on fly ash and deposit properties, straw was co-fired with three kinds of coal in an entrained flow reactor. The compositions of the produced ashes were compared to the available literature data to f...

  17. Coal Ash Corrosion Resistant Materials Testing

    Energy Technology Data Exchange (ETDEWEB)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2003-08-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a reasonably high alkali content, thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was well within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that the aggressive alkali-iron-trisulfate constituent was present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. This report provides the results of the evaluation of Test Section C, including the samples that remained in the Test Section for the full exposure period as well as those that were removed early. The analysis of Test Section C followed much the same protocol that was employed in the assessment of Test Section A. Again, the focus was on determining and documenting the relative corrosion rates of the candidate materials. The detailed results of the investigation are included in this report as a series of twelve appendices. Each appendix is devoted to the performance of one of the candidate alloys. The table below summarizes metal loss rate for the worst case sample of each of the candidate materials for both Test Sections A and C. The body of this report compares these for all of the samples in the test section. The 'Coal Ash Corrosion Resistant Materials Testing Program' is being conducted by The Babcock & Wilcox Company (B&W), the U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) at Reliant Energy's Niles plant in Niles, Ohio to provide full-scale, in-situ testing of recently developed boiler superheater materials. Fireside corrosion is a key issue for improving efficiency of new coal fired power plants and improving service life in existing plants. In November 1998, B&W began development of a system to permit testing of advanced tube materials at metal temperatures typical of advanced supercritical steam temperatures (1100 F and higher) in a boiler exhibiting coal ash corrosive conditions. Several materials producers including Oak Ridge National Laboratory (ORNL) contributed advanced materials to the project. In the spring of 1999 a system consisting of three identical sections, each containing multiple segments of twelve different materials, was installed. The sections are cooled by reheat steam, and are located just above the furnace entrance in Niles Unit No.1, a 110 MWe unit firing high sulfur Ohio coal. In November 2001 the first section was removed for thorough metallurgical evaluation after 29 months of operation. The second section was removed in August of 2003. Its evaluation has been completed and is the subject of this report. The final section remains in service and is expected to be removed in the spring of 2005. This paper describes the program; its importance, the design, fabrication, installation and operation of the test system, materials utilized, and experience to date. This report briefly reviews the results of the evaluation of the first section and then presents the results of the evaluation of the second section.

  18. Physical and biological studies of coal and oil fly ash.

    OpenAIRE

    Fisher, G. L.; McNeill, K L; Prentice, B A; McFarland, A R

    1983-01-01

    Studies were performed to compare the physical and chemical characteristics and the in vitro macrophage cytotoxicity of oil and coal fly ash. Sampling methodology was developed to collect size-fractionated particulate matter from the smokestack of either a coal-fired or an oil-fired power plant. Morphological studies demonstrated particle heterogeneity, although most coal fly ash particles appeared to be spherical. Oil fly ash contained two major morphologies; nonopaque amorphous particles an...

  19. Ash transformation during co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt

    2007-01-01

    Co-firing straw with coal in pulverized fuel boilers can cause problems related to fly ash utilization, deposit formation, corrosion and SCR catalyst deactivation due to the high contents of Cl and K in the ash. To investigate the interaction between coal and straw ash and the effect of coal quality on fly ash and deposit properties, straw was co-fired with three kinds of coal in an entrained flow reactor. The compositions of the produced ashes were compared to the available literature data to find suitable scaling parameters that can be used to predict the composition of ash from straw and coal co-firing. Reasonable agreement in fly ash compositions regarding total K and fraction of water soluble K was obtained between co-firing in an entrained flow reactor and full-scale plants. Capture of potassium and subsequent release of HCl can be achieved by sulphation with SO2 and more importantly, by reaction with Al and Si in the fly ash. About 70-80% K in the fly ash appears as alumina silicates while the remainder K is mainly present as sulphate. Lignite/straw co-firing produces fly ash with relatively high Cl content. This is probably because of the high content of calcium and magnesium in lignite reacts with silica so it is not available for reaction with potassium chloride. Reduction of Cl and increase of S in the deposits compared to the fly ashes could be attributed to sulphation of the deposits.

  20. Effect of chemical composition of coal ash on readings of radioisotope ash meters

    International Nuclear Information System (INIS)

    About 150 radioisotope ash meters, the readings of which are mostly used for operational control of processing operations, have been introduced at coal mining and coal processing facilities of the USSR. In addition to the significant advantages of these instruments (contactless instruments, speed, good representativeness of control), operation has also detected a number of series shortcomings, the principal one of which can be considered the effect of changes in ash composition on the measurement results. Since operation of nearly all radioisotope ash meters is based on the connection between effective atomic number of coal Z and its ash content, the distribution of light aluminosilicates and heavy ash-forming compounds of calcium and iron in the ash leads to changes of Z that are not correlated with ash content and, as a result, a significant error in control. Analysis of the effect of chemical composition of the coal ash on the readings of radioisotope ash meters was carried out on the basis of data from introduction and operation at the concentration plant of the Neryungrinsk Open-Pit Mine of the Yakutskugol Production Association of instruments to control coal ash content on line (RKTP-2) using the intensity of backscattered low-energy (60 keV) radiation as a function of ash content of the coal. The method of preliminary analysis of data on ash composition of coal proposed by the authors provides for evaluating the nonuniformity of the obtained data set, determination of the minimal admissible number of calibrations from the standpoint of measurement error and finally establishment of the optimal sensitivity to ash content corresponding to these calibration

  1. Multitechnique multielemental analysis of coal and fly ash

    International Nuclear Information System (INIS)

    The coal sample is first ashed with high temperature ashing or with RF plasma low temperature ashing. The coal ash or fly ash can be analyzed for major ash elements by fusing with lithium tetraborate in an automatic fusion device, the Claisse Fluxer. The ash samples are also dissolved in a Parr bomb in a mixture of aqua regia and HF. Subsequently, the solutions are analyzed for eight major (Al, Ca, Fe, K, Mg, Na, Si, and Ti) and 20 trace elements (As, B, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, P, Pb, Sb, Se, Sr, U, V, and Zn) by inductively coupled plasma emission spectroscopy. Mercury in coal and fly ash is determined on a separate aliquot by the cold vapor atomic absorption technique. Fluorine and chlorine in the samples are determined by fusing with Na2CO3 and Eschka mixture, respectively, and then measuring the two ions in solution with specific ion electrodes. Oxygen in the samples can be determined rapidly and nondestructively by 14-MeV neutron activation analysis. These methods have been tested by analyzing several NBS coal and fly ash standards with good accuracy and reproducibility. 10 tables

  2. Application of zeolitised coal fly ashes to the depuration of liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Emilia Otal; Luis F. Vilches; Natalia Moreno; Xavier Querol; Jose Valea; Constantino Fernandez-Pereira [Universidad de Sevilla, Seville (Spain). Dpto. Ingenieria Quimica y Ambiental, E.S. Ingenieros Industriales

    2005-08-01

    In this study, the application of some zeolitised fly ashes and synthetic zeolites to the decontamination of the leachate produced in a municipal solid waste (MSW) treatment plant and to the liquid waste from a pig farm was analyzed. Thus, the reduction of organic matter (BOD and COD), ammonium and total nitrogen, phosphorus and metals contents after a zeolite treatment was evaluated. Several synthetic zeolites were tested: some commercial zeolites and other synthetic zeolites and zeolitised ashes obtained after a coal fly ash alkaline hydrothermal process. Two forms of contact between the zeolitic material and the liquid waste were tested: in a stirred tank and in a column. In addition, other variables determined were the amount of zeolite and the residence time. The results showed that zeolites, especially zeolitised fly ash, clearly produced a strong reduction in the leachate nitrogen and phosphorus content. 14 refs., 1 fig., 9 tabs.

  3. Mössbauer Studies of Thermal Power Plant Coal and Fly Ash

    Science.gov (United States)

    Taneja, S. P.

    Iron-57 Mössbauer spectroscopic studies were carried out at room temperature on samples of coal, slag (bottom ash) and mechanical ash collected from Bhatinda (India) thermal power plant. Hyperfine parameters such as isomer shift, quadrupole splitting and total internal magnetic field of 57Fe nuclei were used to characterize various iron-bearing minerals. The observed parameters indicate the presence of pyrite, siderite and ankerite in coal sample while magnetic fractions of mechanical ash and slag samples show the formation of hematite and Al-substituted magnesio-ferrite. The non-magnetic fraction of slag ash shows the dominance of Fe2+ phases while that of mechanical ash demonstrates the formation of both Fe2+ and Fe3+ phases. These findings are compared with Mössbauer and magnetic susceptibility studies on fly ash samples of Panipat (India) thermal power plant reported earlier.

  4. Coal mineral transformations - effects on boiler ash behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Wigley, F.; Williamson, J. [Imperial College of science, Technology and Medicine, London (United Kingdom). Dept. of Materials

    2005-03-01

    This project was undertaken to provide UK boiler designers and operators with an improved knowledge of the combustion characteristics of coals for which they had little combustion experience. The study placed particular emphasis on the effects that a wider range of coal minerals and mineral matter distributions might have on the many aspects of boiler operation. These ranged from coal grinding for pulverised coal combustion, to combustion behaviour, levels of unburned carbon in ash, precipitator performance, gaseous and particulate emissions, and the slagging and fouling characteristics of the ash. 26 refs., 3 figs., 14 tabs., 3 apps.

  5. Composting coal ash with poultry litter for topsoil manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, H.L.; Carr, L.E.; Biermann, E.K.; Christiana, G.A.; Udinskey, J.R. [University of Maryland, College Park, MD (United States). Dept. of Biological Resources Engineering

    1996-12-31

    This paper describes the progress of studies using coal ash mixed with organic byproducts in a compost process as a means of converting ash to a desirable commercial product. Mixtures of fly and bottom ash, broiler chicken littler manure, sawdust and pine bark were successfully composted during the winter of 1994. The recipes and compost procedures for production of the manufactured soils are described. The physical, biological and chemical properties of the manufactured soils are being studied and the initial results presented.

  6. Mutagenicity of filtrates from respirable coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Chrisp, C.E.; Fisher, G.L.; Lammert, J.E.

    1978-01-06

    Incubation of histidine-requiring auxotrophs of the bacterium Salmonella typhimurium with cyclohexane-, saline-, and serum-soluble surface components of respirable fly ash particles produced an increased number of revertants in two frameshift tester strains. The results are consistent with the hypothesis that both organic and inorganic mutagens are present in coal fly ash.

  7. Beneficiation of coal pond ash by physical separation techniques.

    Science.gov (United States)

    Lee, Sung-Joo; Cho, Hee-Chan; Kwon, Ji-Hoe

    2012-08-15

    In this study, investigations to develop a beneficiation process for separating coal pond ash into various products were undertaken. To this end, coal pond ash samples with different particle size ranges were tested in terms of their washability characteristics in a float-and-sink analysis. It was found that coal pond ash was heterogeneous in nature consisting of particles that varied in terms of their size and composition. However, it can be made more homogenous using a gravity separation method. Therefore, the possibility of separating coal pond ash was tested on standard equipment typically used for gravity concentration. To increase the separation efficiency, coal ash was separated according to the size of the particles and each size fraction was tested using equipment appropriate for the corresponding sizes. A hindered-settling column and a shaking table were tested for their ability to treat the 1.19 × 0.074 mm size fraction, and a Falcon concentrator was evaluated for its ability to treat the -0.074 mm size fraction. The results showed that various marketable products, such as lightweight aggregate, sand and high-carbon fuel, can be recovered from coal pond ash using simple physical separation techniques. PMID:22484657

  8. Environmentally friendly use of non-coal ashes in Sweden.

    Science.gov (United States)

    Ribbing, C

    2007-01-01

    The Swedish Thermal Engineering Research Institute (Värmeforsk) initiated an applied research program "Environmentally friendly use of non-coal ashes", in 2002. The program aims at increasing knowledge on the by-products of energy production and their application. The goal of formulating technical and environmental guidelines and assessments is a major point of the program, which is supported by about forty authorities and private organisations. The programme has been divided into four areas: recycling of ashes to forests, geotechnical applications, use in landfilling, and environmental aspects and chemistry. Among all results obtained, the following progress is shown: *Evidence for the positive effects of spreading ashes on forest growth. *A proposal for environmental guidelines on the utilisation of ashes in construction. *A handbook for using non-coal fly ashes in unpaved roads. *Technical and environmental assessments of MSWI bottom ashes in road construction. *Development of the use of ashes with municipal wastewater sludge as a cover for landfills and mine tailings. *Use of ashes from bio-fuels in concrete and replacement of cement in stoop mining. *A method to classify those by-products from combustion that have mirror entries in the EWC as a hazardous or non-hazardous compound. The Ash Programme has also made it possible to increase knowledge on ashes as valuable materials, on quality assurance and on markets for recovered materials. PMID:17521898

  9. Coal Ash Corrosion Resistant Materials Testing

    Energy Technology Data Exchange (ETDEWEB)

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2007-12-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that, due to excessive wastage, certain tube samples needed to be removed and replaced in order to ensure that Test Sections B and C would have a chance of remaining in the boiler for their intended exposure period. These suspect tube samples were replaced and the two remaining test sections were put back into service. The tube samples that were removed from Test Sections B and C were set aside for later analysis at the end of the planned exposure period. Test Sections B and C were again examined approximately six months later. At that time, measured wall thickness losses raised concerns about additional tube samples. These suspect samples were also removed, set aside for later analysis, and replaced. The test sections then went back into service until the end of the second exposure period, which was concluded in May 2003 when, due to evidence of excessive wastage, the valves were opened increasing cooling steam flow and thereby effectively stopping corrosion. In August 2003, Test Sections B and C were removed for closer examination. Section C had experienced about 42 months of service at the desired team temperature set point with 28.5 months at temperature at full temperature. Additional suspect samples were removed from Test Section B, then, it was re-installed into the boiler (at the location originally occupied by Section C), where it remained in service until the end of the program. Due to this removal history, the samples from Test Section B had a total service duration that varied from a minimum of 15.5 months (for samples that performed poorly) to 37 months for samples the survived for the full intended service exposure for Section B. The figure below shows a schematic of Test Section B and indicates the length of service exposure for different locations. This report provides the results of the evaluation of Test Section B, including the samples that remained in the Test Section for the full exposure period as well as those that were removed early. This report also is intended to compare and summarize the results for all three test sections. The analysis of T

  10. Gamma isotopic analysis of the coals and ashes from coal fired power plants of Turkey

    International Nuclear Information System (INIS)

    Gamma-isotopic analysis of the ashes produced by the combustion of lignite in power stations of Turkey together with the parent coal samples was performed with the aim to estimate its potential adverse impacts on human health. Gamma-isotopic analysis indicated that all samples contained 226Ra (coal samples: 89-148 Bq kg-1; ash samples: 15-26 Bq kg-1), 238U (coal samples: 2-4 ?g g-1; ash samples: 9-33 ?g g-1), 232Th (coal samples: 1-9 ?g g-1; ash samples: 8-12?g g-1), and 40K (coal samples: 26-67 Bq kg-1; ash samples: not detected). 134Cs and 137Cs have not been found in the samples. (author)

  11. Utilization of Coal Fly Ash as CO Gas Adsorbent

    Directory of Open Access Journals (Sweden)

    Ayu Lasryza

    2012-10-01

    Full Text Available This research focused on coal fly ash fabricated as CO adsorbent. Coal fly ash having grain size of 325 mesh was characterized by XRF, XRD and SEM-EDX. Physical activation was done at temperatures of 5000C, 5200C, 5400C, 5600C, 5800C and 6000C. Chemical activation was undertaken by mixing between fly ash and NaOH with mass ratio of 1: 1.2 with subsequent heating at 7500C for 1 h and followed by washing the specimens until pH=7. The samples were dried at 1000C for 1 h. The major constituents of unactivated coal fly ash are Fe, Ca, K, Si and Al in the form of quatz and anorthite. The chemical activation led to reduce the amount of quartz or increase the amount of anorthite. Physical activation does not affect the amount of minerals. Surface area of coal fly ash with physical activation at temperature 5400C and chemical activation is 32.444 m²/g (BET.doi: http://dx.doi.org/10.12777/ijwr.2.2.2012.13-15 [ How to cite this article: Sawitri, D., & Lasryza, A. (2012. Utilization of Coal Fly Ash as CO Gas Adsorbent. International Journal of Waste Resources (IJWR, 2(2, 13-15. doi: http://dx.doi.org/10.12777/ijwr.2.2.2012.13-15

  12. Growth and elemental accumulation by canola on soil amended with coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Yunusa, I.A.M.; Manoharan, V.; DeSilva, D.L.; Eamus, D.; Murray, B.R.; Nissanka, S.P. [University of Technology Sydney, Sydney, NSW (Australia)

    2008-05-15

    To explore the agronomic potential of an Australian coal fly ash, we conducted two glasshouse experiments in which we measured chlorophyll fluorescence, CO{sub 2} assimilation (A), transpiration, stomatal conductance, biomass accumulation, seed yield, and elemental uptake for canola (Brassica napus) grown on soil amended with an alkaline fly ash. In Experiment 1, application of up to 25 Mg/ha of fly ash increased A and plant weight early in the season before flowering and seed yield by up to 21%. However, at larger rates of ash application A, plant growth, chlorophyll concentration, and yield were all reduced. Increases in early vigor and seed yield were associated with enhanced uptake of phosphorus (P) by the plants treated with fly ash. Fly ash application did not influence accumulation of B, Cu, Mo, or Zn in the stems at any stage of plant growth or in the seed at harvest, except Mo concentration, which was elevated in the seed. Accumulation of these elements was mostly in the leaves, where concentrations of Cu and Mo increased with any amount of ash applied while that of B occurred only with ash applied at 625 Mg/ha. In Experiment 2, fly ash applied at 500 Mg/ha and mixed into the whole 30 cm soil core was detrimental to growth and yield of canola, compared with restricting mixing to 5 or 15 cm depth. In contrast, application of ash at 250 Mg/ha with increasing depth of mixing increased A and seed yield. We concluded that fly ash applied at not more than 25 Mg/ha and mixed into the top 10 to 15 cm of soil is sufficient to obtain yield benefits.

  13. Remediação de drenagem ácida de mina usando zeólitas sintetizadas a partir de cinzas leves de carvão Remediation of acid mine drainage using zeolites synthesized from coal fly ash

    OpenAIRE

    Denise Alves Fungaro; Juliana de Carvalho Izidoro

    2006-01-01

    Zeolitic material was synthesized from coal fly ashes (baghouse filter fly ash and cyclone filter fly ash) by hydrothermal alkaline activation. The potential application of the zeolitic product for decontamination of waters from acid mine drainage was evaluated. The results showed that a dose of 30 g L-1 of zeolitic material allowed the water to reach acceptable quality levels after treatment. Both precipitation and cation-exchange processes accounted for the reduction in the pollutant concen...

  14. Utilisation of coal ash to improve acid soil

    Directory of Open Access Journals (Sweden)

    Shigeru Kato

    2004-09-01

    Full Text Available The study on utilization of coal ash to improve acid soil was carried out in a greenhouse at the Land Development Regional Office 1, Pathum Thani Province, Central Thailand, from January-May 2003. Fly ash mixture (fly ash plus gypsum and lime at the proportion 5:4:1 and clinker ash mixture (clinker ash plus gypsum and lime at the proportion 5:4:1 were used as soil amendments at varying rates i.e., 0, 6.25,12.5, 18.75 and 25 t/ha to improve the soil. The aim of this study was to determine the effect of application of coal ash on acid soil and the growth of a vegetable (Chinese kale. Chinese kale cultivars were planted in a randomized complete block design with three replications. Pak Chong soil series (Ultisols was used as the growth medium. Twenty-day-old seedlings were transplanted in 270 pots (two plants per pot containing acid soil with different treatments of coal ash mixture which were as follows: 1 control, 2 fly ash mixture 6.25 t/ha, 3 fly ash mixture 12.5 t/ha, 4 fly ash mixture 18.75 t/ha, 5 fly ash mixture 25 t/ha, 6 clinker ash mixture 6.25 t/ha, 7 clinker ash mixture 12.5 t/ha, 8 clinker ash mixture 18.75 t/ha and 9 clinker ash mixture 25 t/ha. Chemical fertilizers were applied at the rate of 250 kg/ha using a grade of 15-15-15 of N, P and K, respectively. Plants were harvested 40 days after transplanting. Among the treatments, application of fly ashmixture at a rate of 25t/ha (4t/rai substantially increased soil pH up to 5.7. Fly ash was found more effective than clinker ash in increasing soil pH. The highest yield of Chinese kale was also obtained when fly ash mixture was applied at a rate of 25 t/ha followed by fly ash mixture at 18.75 t/ha and clinker ash mixture at 18.75 t/ha with an average yield per plant of 4.980, 3.743 and 3.447 grams, respectively. It can be concluded that the application of coal ash mixture, either fly- or clinker ash, at 18.75-25 t/ha (3-4 t/rai was the most effective in terms of plant yield. The use of coal ash mixture increased cation exchange capacity, base saturationpercentage and Ca, Mg and S contents in the soil as well as plant uptake of N. The concentrations of heavy metals in the soil (Cd, As, Co, Cr, Cu, Hg, Ni, Pb and Zn were found to be within permissible levels while Cd, Cr and Ni in the plants were at critical levels for health.

  15. Use of lignite fly ash as an additive in alkaline stabilisation and pasteurisation of wastewater sludge

    Energy Technology Data Exchange (ETDEWEB)

    Kocaer, F.O.; Alkan, U.; Baskaya, H.S. [Uludag University, Bursa (Turkey). Faculty of Engineering & Architecture

    2003-10-01

    The possibility of using lignite fly ash in low doses for reducing the pathogen levels in wastewater sludge was investigated. The results showed that using fly ash alone in doses of 40%,80% and 120% (on a dry weight basis), did not produce an alkaline environment for an efficient removal of pathogens. However, using fly ash in conjunction with the minimum amount of quicklime may act as an effective way of fecal coliform removal in both alkaline stabilisation and pasteurisation processes. It was shown that using fly ash in doses of 80% and 120% in alkaline stabilisation and pasteurisation processes prevented the pH decays and regrowth of pathogens during 60 days of storage period. The results of the study confirmed that alkaline pasteurisation process produces a product which is more resistant to pH decays and regrowth of fecal coliforms compared to that of alkaline stabilisation. Consequently, the overall results of this study indicated that the minimum lime and fly ash dosages required to generate a Class B biosolid were 10-15% and 80%, respectively. On the other hand, heating sludge to 50{degree}C prior to the addition of 10-15% quicklime and 80% fly ash followed by further heating to 70{degree}C and then sustaining at this temperature for 30 minutes were sufficient to generate a Class A biosolid.

  16. Chemical speciation of vanadium in coal bottom Ash

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Firat; Aydin, Isil; Hamamci, Candan [Science Faculty, Chemistry Department, Dicle University, Diyarbakir (Turkey); Saydut, Abdurrahman [Engineering Faculty, Mining Engineering Department, Dicle University, Diyarbakir (Turkey); Gunduz, Beniz [Science Faculty, Chemistry Department, Selcuk University, Konya (Turkey)

    2012-04-15

    Chemical speciation of vanadium is important to understand the true nature of this element in the environment as well as its biochemical pathways. Sample pretreatment, preparation, and chemical speciation methods were applied for vanadium in coal bottom ash here. Two-stage microwave acid digestion was used to preparation of samples. Determination of vanadium was performed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Speciation of vanadium was carried out using a seven-step sequential extraction procedure of the coal bottom ash each releasing species of vanadium: Water soluble, exchangeable, carbonate, reducible, oxidizable, sulfide, and residual fractions. Total vanadium concentration in the coal bottom ash is 701 mg kg{sup -1} d.w. The most abundant form of vanadium in coal bottom ash is residual fraction of vanadium (196 mg kg{sup -1} d.w.). Relative abundances of the remaining vanadium fractions in coal bottom ash are as follows: Reducible (176 mg kg{sup -1} d.w.) > sulfide (176 mg kg{sup -1} d.w.) > carbonate (85 mg kg{sup -1} d.w.) > oxidizable (50 mg kg{sup -1} d.w.) > water soluble (10.6 mg kg{sup -1} d.w.) > exchangeable (9.0 mg kg{sup -1} d.w.). (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. COAL-FIRED UTILITY BOILERS: SOLVING ASH DEPOSITION PROBLEMS; TOPICAL

    International Nuclear Information System (INIS)

    The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems

  18. Characteristic of elements in coal bottom ash and fly ash by instrumental neutron activation analysis (INAA)

    International Nuclear Information System (INIS)

    Coal-fired power plant and industrial stacks that using coal produce solid waste such as bottom ash and fly ash. Determination of elements in these wastes qualitatively and quantitatively is usually the first step taken for subsequent evaluation of the associated environmental and biological risks. In this study, the determination of trace elements in bottom ash and fly ash by instrumental neutron activation analysis was carried out. The samples were irradiated at rabbit facility in G.A. Siwabessy reactor with neutron flux ~ 1013 n.cm-2.s-1, and then counted by HPGe spectrometer gamma detector. The validation of method was performed by characterization of standard reference material (SRM) 1633b coal fly ash from National Institute of Standards and Technology (NIST). Some elements such as Al, As, Ce, Co, Cr, Cs, Fe, K, La, Mn, Na, Sc, Sm, Ti and V were detected in both samples. The concentration of environmentally toxic elements, As and Cr in bottom ash were 6.24 and 137.4 mg/kg, whereas in fly ash were 6.37 and 39.0 mg/kg respectively. Arsenic concentrations had been over the standard value based on PP no.85/1999. (author)

  19. Measurement of soot and char in pulverized coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Veranth, J.M.; Fletcher, T.H.; Pershing, D.W.; Sarofim, A.F. [University of Utah, Salt Lake City, UT (USA). Dept. of Chemical and Fuels Engineering

    2000-07-01

    The unburned carbon in the fly ash produced by low-NOx pulverized coal combustion has been shown by electron microscopy to be a mixture of porous coal char particles and aggregates of submicron particles, which are thought to be soot. The carbon is bimodally distributed with large soot aggregates mixed with the char in the particles larger than 10{mu}m and dispersed soot found with the submicron particles. A method for determining the mass of soot and char by liquid-suspension gravity separation was used with both laboratory-scale and power plant fly ash samples. For low-NOx staged, pilot-scale combustion of bituminous coal the soot in the furnace exit ash was estimated to be 0.2-0.6% of the fuel carbon, which was about 35% of the total unburned carbon. 23 refs., 5 figs., 3 tabs.

  20. Influence of Coal Blending on Ash Fusibility in Reducing Atmosphere

    Directory of Open Access Journals (Sweden)

    Mingke Shen

    2015-05-01

    Full Text Available Coal blending is an effective way to organize and control coal ash fusibility to meet different requirements of Coal-fired power plants. This study investigates three different eutectic processes and explains the mechanism of how coal blending affects ash fusibility. The blended ashes were prepared by hand-mixing two raw coal ashes at five blending ratios, G:D = 10:90 (G10D90, G:D= 20:80 (G20D80, G:D = 30:70 (G30D70, G:D = 40:60 (G40D60, and G:D = 50:50 (G50D50. The samples were heated at 900 °C, 1000 °C, 1100 °C, 1200 °C, and 1300 °C in reducing atmosphere. XRD and SEM/EDX were used to identify mineral transformations and eutectic processes. The eutectic processes were finally simulated with FactSage. Results show that the fusion temperatures of the blended ashes initially decrease and then increase with the blending ratio, a trend that is typical of eutectic melting. Eutectic phenomena are observed in D100, G10D90, and G30D70 in different degrees, which do not appear in G100 and G50D50 for the lack of eutectic reactants. The main eutectic reactants are gehlenite, magnetite, merwinite, and diopside. The FactSage simulation results show that the content discrepancy of merwinite and diopside in the ashes causes the inconsistent eutectic temperatures and eutectic degrees, in turn decrease the fusion temperature of the blended ash and then increase them with the blending ratio.

  1. Is coal ash and slag any useful or unloaded wastes?

    International Nuclear Information System (INIS)

    It is well known that all types of coal, like most materials found in nature, contain trace quantities of the naturally occurring primordial radionuclides (uranium and thorium families and potassium-40). Therefore, the combustion of coal results in partitioning of radionuclides included in the non-combustible mineral matter, between the bottom ash and fly ash, and in the release into the environment of large amounts of coal ash. Emissions from thermal power stations in gaseous and particulate form contain radioisotopes arising from the uranium and thorium series as well as from 40K. They are discharged into the environment causing changes in the natural radiation background and radiation exposures to the population. The continued releases of these materials to environment may result in a buildup in the air, water and soil of the radionuclides, particularly radium-226. There will be an increase of the basic radiation rate in the neighborhood area of these plants and consequently relatively higher exposure of the local population to radiation. Coal burning is, therefore, one of the sources of technologically enhanced exposure to humans from natural radionuclides (1,2,3,4,5,6). Coal based thermal power plants constitute about 35% of quantum of energy supply in Romania. In view of the importance of coal for energy supply in Romania, we were interested in knowing possible uses of the resulting wastes and minimize the following harmful consequences of coal burning

  2. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    2006-01-01

    In this literature report is provided a status for the present knowledge level on ash properties when co-firing coal and biomass. The fly ash formed in boilers using co-firing of coal and straw do have a large influence on ash deposit formation, boiler corrosion, fly ash utilization and operation of flue gas cleaning equipment. This survey includes discussions on the inorganic constituents transformation during straw and coal combustion, alkali-ash and alkali sulfur reactions, a survey of power ...

  3. Synthesis of high ion exchange zeolites from coal fly ash

    OpenAIRE

    Querol Carceller, Xavier

    2007-01-01

    This study focuses on the synthesis at a pilot plant scale of zeolitic material obtained from the coal fly ashes of the Teruel and Narcea power plants in Spain. After the optimisation of the synthesis parameters at laboratory scale, the Teruel and Narcea fly ashes were selected as low and high glass fly ashes. The pilot plant scale experiments were carried out in a 10 m3 reactor of Clariant SA (Barcelona, Spain). The results allowed obtaining 1.1 and 2.2 tonnes of zeolitic material with 40 an...

  4. Synthesis of high ion exchange zeolites from coal fly ash

    OpenAIRE

    Ayora, Carlos; Querol, Xavier; Moreno, N.; Alastuey, Andrés; Juan Mainar, Roberto; Andrés Gimeno, José Manuel; López Soler, Ángel; Medinaceli, Alejandro; Valero, Antonio

    2007-01-01

    This study focuses on the synthesis at a pilot plant scale of zeolitic material obtained from the coal fly ashes of the Teruel and Narcea power plants in Spain. After the optimisation of the synthesis parameters at laboratory scale, the Teruel and Narcea fly ashes were selected as low and high glass fly ashes. The pilot plant scale experiments were carried out in a 10 m3 reactor of Clariant SA (Barcelona, Spain). The results allowed obtaining 1.1 and 2.2 tonnes of zeolitic materia...

  5. Studies on the leaching and weathering processes of coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Liem, H.; Sandstroem, M.; Wallin, T.; Carne, A.; Blomqvist, L.; Thurenius, B.; Rydevik, U.; Moberg, P.O.

    1983-05-01

    The Swedish State Power Board has commissioned the Department of Inorganic Chemistry, the Department of Analytical Chemistry at The Royal Institute of Technology (KTH) and Scandiaconsult to make research studies within the project KHM 322 which is part of the Coal-Health-Environment project. Within the project KHM 322 we made leaching studies on the following types of coal combustion residues: fly ashes, bottom ashes, scrubber sludge, used bed material, other materials. Masspectrometric analysis show the ashes to contain about fifty elements. Coal ashes, scrubber sludge and used bed material contain considerable amounts of pH-buffering substances which will give the leachate a strong basic reaction (ph=9-13). Oil ashes give on the other hand an acid reaction (ph=2) when coming in contact with water. For a given type of coal the alcalinity of the fly ash is equal or greater than the corresponding bottom ash. The metal leaching from the different types of ashes has been compared for the metals, chromium, cobolt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium and lead, under the same leaching conditions. The leaching of the metal was found to increase with pH for pH<=2 and ph>=9, to decrease with pH for 2 < pH < 6 and its minimum value at pH around 6 to 7. The effects for pH > 2 can be explained by solubility and complex formation equilibria. To study the effects ofleaching time on the metal leaching a set of long term experiments were carried out on some fly ashes and one bottom ash. For part of the ashes the leaching was carried out for up to 6 months with several changes of leachate and with leachate of different pH values. The pH of the leachate was found to reach quickly the equilibrium value and that the value then remained constant as long as there were pH buffering substances left in the ashes.

  6. Community views about the health and exposure of children living near a coal ash storage site.

    Science.gov (United States)

    Zierold, Kristina M; Sears, Clara G

    2015-04-01

    Coal ash, a waste product generated from burning coal, is composed of small particles comprised of highly toxic elements. Coal ash particles contain heavy metals such as arsenic, lead, and mercury, as well as polyaromatic hydrocarbons and radioactive elements. Most coal ash is stored in landfills and ponds, often located in close proximity to low income communities. Currently, there are no federal regulations governing the storage and transport of coal ash; however the Environmental Protection Agency proposed a coal ash rule in 2010, which could designate coal ash as a hazardous waste. This is the first article to assess community impact from coal ash storage, by exploring parents' perceptions of their children's health and its relationship to chronic exposure to coal ash. This was a community-based study involving four neighborhoods adjacent to a large coal ash storage facility. Focus groups were conducted with community members and the transcripts were analyzed to identify themes regarding children's health, children's exposure to coal ash, and behaviors done to protect children from exposure. The majority of parents (85 %) reported that their children suffered from health conditions; specifically respiratory and emotional and behavioral disorders. Parents highlighted ways in which their children were exposed to coal ash, although many felt they were constantly exposed just by living in the area. Parents felt strongly that exposure to coal ash from the landfill is affecting the health and well-being of their children. Some parents attempted protective behaviors, but most parents felt helpless in reducing children's exposure. PMID:25204532

  7. Properties of Concrete using Tanjung Bin Power Plant Coal Bottom Ash and Fly Ash

    Directory of Open Access Journals (Sweden)

    Abdulhameed Umar Abubakar

    2012-11-01

    Full Text Available Coal combustion by-products (CCPs have been around since man understood that burning coal generates electricity, and its utilization in concrete production for nearly a century. The concept of sustainable development only reawaken our consciousness to the huge amount of CCPs around us and the need for proper reutilization than the current method of disposal which has  severe consequences both to man and the environment. This paper presents the result of utilization of waste from thermal power plants to improve some engineering properties of concrete. Coal bottom ash (CBA and fly ash were utilized in partial replacement for fine aggregates and cement respectively. The results of compressive strength at 7, 28, 56 & 90 days curing are presented because of the pozzolanic reaction. Other properties investigated include physical properties, fresh concrete properties and density. The results showed that for a grade 35 concrete with a combination of CBA and fly ash can produce 28 day strength above 30 MPa.

  8. Study of the correlation between the coal calorific value and coal ash content using X-ray fluorescence analysis

    Science.gov (United States)

    Bolortuya, D.; Zuzaan, P.; Gustova, M. V.; Maslov, O. D.

    2013-12-01

    In this paper we have studied the possibility of determining the chemical elements in coal samples using X-ray fluorescence analysis and have found a relationship between the coal calorific value and its ash content with the coal moisture accounting. The amount of coal ash can be determined by the content of the basic chemical elements, such as Si, Sr, Fe, and Ca. It was concluded that the calorific value of coal can be estimated from the ash content in coal without the calorimetric measurements. These correlation coefficients were calculated for coal from several coal mines in Mongolia. The results are in good agreement with the results of chemical analysis.

  9. Long-term evaluation of coal fly ash and mine tailings co-placement: a site-specific study.

    Science.gov (United States)

    Yeheyis, Muluken B; Shang, Julie Q; Yanful, Ernest K

    2009-10-01

    This study presents the results of a laboratory investigation conducted to evaluate the efficiency of coal fly ash to control the formation of acid mine drainage (AMD) from mine waste. Site-specific materials, coal fly ash from Atikokan Thermal Generating Station and mine tailings from Musselwhite mine, were mixed at different proportions for the investigation of the drainage chemistry and the optimal mix using static testing (acid-base accounting) and kinetic (column) testing. The acid-base accounting (ABA) results indicated that the fly ash possessed strong alkaline (neutralization) potential (NP) and could be used in the management of reactive mine tailings, thus ensuring prevention of AMD in the long-term. Column tests conducted in the laboratory to further investigate long-term performance of fly ash in the neutralization and prevention of acid mine drainage from tailings similarly showed that mixing fly ash with mine tailings reduces dissolution of many heavy metals from tailings by providing alkalinity to the system. It was found that a fly ash to tailings mass ratio equal to or greater than 15% can effectively prevent AMD generation from Musselwhite mine tailings in the co-placement approach. PMID:19744768

  10. Combustion characteristics of high ash coal in a pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kurose, R.; Ikeda, M.; Makino, H. [Central Research Institute of Electric Power Industry (CRIEPI), Yokosuka-shi (Japan). Chemical Energy Engineering Department, Yokosuka Research Laboratory

    2001-08-10

    The influences of ash content on pulverized coal combustion characteristics are experimentally and numerically studied under a staged combustion condition. The stage combustion ratio (the ratio of air volume of the staged combustion air to the total air) is 0 to 30%, and the coals tested are the three high ash coals with different ash contents of 36, 44 and 53 wt%, which were separated using the flotation method. The results show that as the ash content increases, gas temperature decreases and O{sub 2} consumption and NOx formation becomes slow near the burner. Also, the increase of the ash content leads to the increase in NOx concentration and unburned carbon fraction at the furnace exit. The reasons being, for the high ash coal, the large heat capacity of the ash and the covering of combustible matter suppress combustibility with ash during the char oxidation. The numerical simulations designed to match the experimental setup for the staged combustion show that the numerical results are in general agreement with the measurements. 14 refs., 13 figs., 2 tabs.

  11. Alkaline leaching of coal by the mechanochemical treatment

    Directory of Open Access Journals (Sweden)

    Turèániová ¼udmila

    1998-09-01

    Full Text Available The possibility of application of a new process GACL (Grinding and Aqueous Caustic Leaching for the reduction of mineral components in the brown coal Nováky was tested. The simultaneous grinding and chemical leaching enable us to extract 41 % total sulphur, 95 % arsenic and to reduce the ash content to 43 %. The process proceeds at the atmospheric pressure, temperature 90oC and in diluted NaOH solutions (5 %.

  12. Alkaline leaching of coal by the mechanochemical treatment

    OpenAIRE

    Turèániová ¼udmila; Balá? Peter

    1998-01-01

    The possibility of application of a new process GACL (Grinding and Aqueous Caustic Leaching) for the reduction of mineral components in the brown coal Nováky was tested. The simultaneous grinding and chemical leaching enable us to extract 41 % total sulphur, 95 % arsenic and to reduce the ash content to 43 %. The process proceeds at the atmospheric pressure, temperature 90oC and in diluted NaOH solutions (5 %).

  13. Revegetation of a coal fly ash - reject landfill

    Energy Technology Data Exchange (ETDEWEB)

    Danker, R.; Adriano, D.C.; Barton, C.; Punshon, T.

    2001-07-01

    Coal-fired power plants dispose of coal fly ash in landfills worldwide. More than 100 million metric tons of fly ash are produced annually in the United States alone and continued worldwide reliance on coal may pose a significant environmental risk. Ecologists at the Savannah River Site (SRS) near Aiken, South Caroline have found high levels of metals in animals exposed to coal fly ash and coal reject from coal burning at their own facility and suspect the problem is widespread. Recent studies have shown that selenium may cause morphological deformities in bullfrog tadpoles and further research into this problem is required. This study began in June 2000 and involved an outdoor tank mesocosm that replicated a coal fly ash basin field study at SRS to find ways to minimize the infiltration rate of water into the substrate. With time, the water becomes acidic leachate from the oxidation of pyrite and significantly damages adjacent ecosystems. Leachate samples were measured for pH and electroconductivity. The levels of various trace elements in the leachate were also discussed. One way to minimize the volume of leachate is to revegetate the area in order to optimize evapotranspiration. The vegetation also acts as a buffer to organic metabolites from root activities and plant decay. Many improvement materials were added in the field to promote the buffering capacity and to improve the physical properties of the substrate. Results indicated that pH has increased since the inception of the study. The biosolid plus topsoil plus surfactant treatment seems to be an effective method for increasing the buffering capacity. The most effective treatment for inducing the lowest electroconductivity values is the addition of topsoil plus surfactant. 1 ref., 2 figs.

  14. Radiometric determination of ash content in brown coal

    International Nuclear Information System (INIS)

    The possibilities of ash content determination in brown coal from the ''Turow'' strip mine, using a portable radioisotope X-ray fluorescence analyser have been investigated. Negative results were obtained when the characteristic radiation of iron was measured. Therefore, in further investigations the scattering of X-rays from 238Pu-source was applied. In this case a vanadium filter was used to eliminate fluorescent radiation of iron. The measurements were carried out on 30 coal samples of variable moisture, containing 13-45 per cent of ash. The experiments have shown that, with measurement times of about 1 min. the absolute standard error of ash content determination is about 2 per cent. (author)

  15. Conversion of different ash content brown coal in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Osipov, P.; Chernyavskiy, N.; Ryzhkov, A.; Remenuk, A. [Ural Federal Univ., Ekaterinburg (Russian Federation). Dept. of Thermal Power Plants; Dulienko, S. [National Academy of Science of Ukraine, Kiev (Ukraine). Coal Energy Technology Inst.

    2013-07-01

    Available equations used to determine combustion specific rate of coal-derived cokes describe the burning of carbon particles well enough but are not accurate in case of ash-containing coke particles combustion. This study is an attempt to account for the influence of both initial ash content and its increase in the course of carbon conversion in specific rate calculations. The results of experimental study of burn-out dynamics of Volchanskiy field (North Urals) brown coal and its coke with different ash content under conditions of fluidized bed combustion at impulse-type non-gradient reactor RSC-1 and dynamic installation Pyrolysis-M are summarized. Diffusion and heterogeneous (kinetic) components of carbon combustion rate are identified separately by using diffusion and kinetics equation with correction for carbon mass fraction in particles. Burning particle overheating values and heterogeneous combustion rate constants at different temperatures are estimated.

  16. Radiocesium Adsorption By Zeolitic Materials Synthesized From Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Remenárová Lucia

    2014-06-01

    Full Text Available Brown coal fly ash derived from the combustion of brown-coal in power plant ENO Nováky (Slovak Republic was used as raw material for synthesis of zeolitic materials ZM1 and ZM3 by hydrothermal alternation with 1M NaOH and 3M NaOH, respectively. Fly ash and synthesized products were characterized using XRF and SEM-EDX analysis. Subsequently, zeolitic materials were tested as sorbents to remove Cs+ ions from aqueous solutions using radiotracer technique. Sorption of cesium by both types of zeolitic materials obeys Langmuir adsorption isotherm model. The maximum sorption capacities Qmax at pH 6.0 calculated from Langmuir isotherm were 1203 ± 65 ?mol Cs+/ g for ZM1 and 1341 ± 66 ?mol Cs+/ g for ZM3. The results showed that alkali treated fly ash can be used as effective sorbent for radiocesium removal from contaminated solutions

  17. Leaching behaviour of elements from coal combustion fly ash : an overview

    OpenAIRE

    Izquierdo, Maria; Querol, Xavier

    2012-01-01

    Coal-based power generation produces over 750 Mt of coal ash per year globally, but under 50% of world production is utilised. Large amounts of fly ash are either stored temporarily in stockpiles, disposed of in ash landfills or lagooned. Coal ash is viewed as a major potential source of release of many environmentally sensitive elements to the environment. This paper encompasses over 90 publications on coal fly ash and demonstrates that a large number of elements are tightly bound to fly ash...

  18. Mode of occurrence of arsenic in feed coal and its derivative fly ash, Black Warrior Basin, Alabama

    Science.gov (United States)

    Zielinski, R.A.; Foster, A.L.; Meeker, G.P.; Brownfield, I.K.

    2007-01-01

    An arsenic-rich (As = 55 ppm) bituminous feed coal from the Black Warrior Basin, Alabama and its derivative fly ash (As = 230 ppm) were selected for detailed investigation of arsenic residence and chemical forms. Analytical techniques included microbeam analysis, selective extraction, and As K-edge X-ray absorption fine-structure (XAFS) spectroscopy. Most As in the coal is contained in a generation of As-bearing pyrite (FeS2) that formed in response to epigenetic introduction of hydrothermal fluids. XAFS results indicate that approximately 50% of the As in the coal sample occurs as the oxidized As(V) species, possibly the result of incipient oxidation of coal and pyrite prior to our analysis. Combustion of pyrite and host coal produced fly ash in which 95% of As is present as As(V). Selective extraction of the fly ash with a carbonate buffer solution (pH = 10) removed 49% of the As. A different extraction with an HCl-NH2OH mixture, which targets amorphous and poorly crystalline iron oxides, dissolved 79% of the As. XAFS spectroscopy of this highly acidic (pH = 3.0) fly ash indicated that As is associated with some combination of iron oxide, oxyhydroxide, or sulfate. In contrast, a highly alkaline (pH = 12.7) fly ash from Turkey shows most As associated with a phase similar to calcium orthoarsenate (Ca3(AsO4)2). The combined XAFS results indicate that fly ash acidity, which is determined by coal composition and combustion conditions, may serve to predict arsenic speciation in fly ash.

  19. High fire resistance in blocks containing coal combustion fly ashes and bottom ash.

    Science.gov (United States)

    García Arenas, Celia; Marrero, Madelyn; Leiva, Carlos; Solís-Guzmán, Jaime; Vilches Arenas, Luis F

    2011-08-01

    Fire resistance recycled blocks, containing fly ash and bottom ash from coal combustion power plants with a high fire resistance, are studied in this paper by testing different compositions using Portland cement type II, sand, coarse aggregate and fly ash (up to 50% of total weight) and bottom ash (up to 30% of total weight). The fire resistance, physical-chemical (density, pH, humidity, and water absorption capacity), mechanical (compressive and flexural strength), and leaching properties are measured on blocks made with different proportions of fly ash and bottom ash. The standard fire resistance test is reproduced on 28cm-high, 18cm-wide and 3cm-thick units, and is measured as the time needed to reach a temperature of 180°C on the non-exposed surface of the blocks for the different compositions. The results show that the replacement of fine aggregate with fly ash and of coarse aggregate with bottom ash have a remarkable influence on fire resistance and cause no detriment to the mechanical properties of the product. Additionally, according to the leaching tests, no environmental problems have been detected in the product. These results lead to an analysis of the recycling possibilities of these by-products in useful construction applications for the passive protection against fire. PMID:21511456

  20. Composition, diagenetic transformation and alkalinity potential of oil shale ash sediments

    International Nuclear Information System (INIS)

    Oil shale is a primary fuel in the Estonian energy sector. After combustion 45-48% of the oil shale is left over as ash, producing about 5-7 Mt of ash, which is deposited on ash plateaus annually almost without any reuse. This study focuses on oil shale ash plateau sediment mineralogy, its hydration and diagenetic transformations, a study that has not been addressed. Oil shale ash wastes are considered as the biggest pollution sources in Estonia and thus determining the composition and properties of oil shale ash sediment are important to assess its environmental implications and also its possible reusability. A study of fresh ash and drillcore samples from ash plateau sediment was conducted by X-ray diffractometry and scanning electron microscopy. The oil shale is highly calcareous, and the ash that remains after combustion is derived from the decomposition of carbonate minerals. It is rich in lime and anhydrite that are unstable phases under hydrous conditions. These processes and the diagenetic alteration of other phases determine the composition of the plateau sediment. Dominant phases in the ash are hydration and associated transformation products: calcite, ettringite, portlandite and hydrocalumite. The prevailing mineral phases (portlandite, ettringite) cause highly alkaline leachates, pH 12-13. Neutralization of these leachates under natural conditions, by rainwater leaching/neutralization and slow transformation (e.g. carbonation) of the aforementioned unstable phases into more stable forms, takes, at best, hundreds or even hundreds of thousands of years.

  1. Study of the correlation between the coal calorific value and coal ash content using X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    In this paper we have studied the possibility of determining the chemical elements in coal samples using X-ray fluorescence analysis and have found a relationship between the coal calorific value and its ash content with the coal moisture accounting. The amount of coal ash can be determined by the content of the basic chemical elements, such as Si, Sr, Fe, and Ca. It was concluded that the calorific value of coal can be estimated from the ash content in coal without the calorimetric measurements. These correlation coefficients were calculated for several coal mines in Mongolia. The results are in good agreement with the results of chemical analysis

  2. Measurement of the ash content of coal

    International Nuclear Information System (INIS)

    An apparatus suitable for determining the noncombustible content of coal in railroad cars or other transportation containers consists of a neutron source, a detector of gamma rays of a predetermined energy characteristic of aluminum 28 and a readout device

  3. The use of coal fly ash for soil stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.H.; Brown, M.A.; Sorini, S.S.; Huntington, G.

    1991-12-01

    The objective of this work was to examine the potential use of Wyoming subbituminous coal fly ash materials for cementation of soil materials. Specimens made from Laramie River (LR) fly ash had higher unconfined compression strength and more brittleness than the Specimens made with Dave Johnston (DJ) fly ash. However, soil/DJ fly ash mixtures that were cured for 28 days had relatively good strengths without the brittleness that the LR specimens developed. These characteristics of the DJ fly ash may be important attributes for road stabilization applications. The detailed mineralogical evaluation provides some insight into which minerals may enhance development of strength in these materials. In general, selective dissolution of the soil/fly ash mixtures shows that many of the potentially toxic elements (e.g., B, Cr, Fe, Mn, Ni, Pb) are associated with the sulfide phase (HNO{sub 3} extractable) and with the residual material. In this study, the dynamics of elemental release from the element pools did not result in toxic conditions. The formation of colloidal material capable of mobilizing potentially toxic elements was not found in the soil/fly ash mixtures. Apparently, the high pH of the materials enhanced immobilization of the high molecular weight material.

  4. Production of ceramics from coal fly ash

    Directory of Open Access Journals (Sweden)

    Angjusheva Biljana

    2012-01-01

    Full Text Available Dense ceramics are produced from fly ash from REK Bitola, Republic of Macedonia. Four types of fly ash from electro filters and one from the collected zone with particles < 0.063 mm were the subject of this research. Consolidation was achieved by pressing (P= 133 MPa and sintering (950, 1000, 1050 and 11000C and heating rates of 3 and 100/min. Densification was realized by liquid phase sintering and solid state reaction where diopside [Ca(Mg,Al(Si,Al2O6] was formed. Ceramics with optimal properties (porosity 2.96±0.5%, bending strength - 47.01±2 MPa, compressive strength - 170 ±5 MPa was produced at 1100ºC using the heating rate of 10ºC/min.

  5. Environmental impact of coal ash on tributary streams and nearshore water or Lake Erie. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wood, K.G.

    1978-08-01

    The environmental impact of coal ash disposal at a landfill site in north-central Chautauqua County, New York was studied from June 1975 through July 1977. Water samples taken from wells, ponds, and streams at 67 sites were analyzed for specific conductance, pH, alkalinity, arsenic, calcium, cadmium, chloride, chromium, copper, iron, magnesium, manganese, potassium, selenium, sodium, sulfate and zinc. Evidence suggests that ponds at the landfill were high in Ca, Fe, Mg, Mn, and SO/sub 4/ compared to control pands. A stream adjacent to the site contained greater Mn (207 ug/1) and SO/sub 4/ (229 ppm) than control streams. Shallow alkaline test wells in the landfill had elevated As, Ca, and Se. Acid-neutral test wells had elevated As, Ca, Cr, Mg and Mn. Household wells in the vicinity of the landfill showed no evident contamination from the landfill. Average iron concentrations in the biota were tripled, and manganese concentrations doubled in biota affected by the coal ash dump. However, any effects of the disposal area on the distribution of the biota could not be separated from effects of varying environment factors such as water movements, substrate composition and food availability. No harmful effects could be demonstrated on the biota in the creek which flowed past the disposal area.

  6. Clay formation and metal fixation during weathering of coal fly ash

    International Nuclear Information System (INIS)

    The enormous and worldwide production of coal fly ash cannot be durably isolated from the weathering cycle, and the weathering characteristics of fly ash must be known to understand the long-term environmental impact. The authors studied the weathering of two coal fly ashes and compared them with published data from weathered volcanic ash, it's closest natural analogue. Both types of ash contain abundant aluminosilicate glass, which alters to noncrystalline clay. However, this study reveals that the kinetics of coal fly ash weathering are more rapid than those of volcanic ash because the higher pH of fresh coal fly ash promotes rapid dissolution of the glass. After about 10 years of weathering, the noncrystalline clay content of coal fly ash is higher than that of 250-year-old volcanic ash. The observed rapid clay formation together with heavy metal fixation imply that the long-term environmental impact of coal fly ash disposal may be less severe and the benefits more pronounced than predicted from previous studies on unweathered ash. Their findings suggest that isolating coal fly ash from the weathering cycle may be counterproductive because, in the long-term under conditions of free drainage, fly ash is converted into fertile soil capable of supporting agriculture

  7. Coal fly ash as a resource for rare earth elements.

    Science.gov (United States)

    Franus, Wojciech; Wiatros-Motyka, Ma?gorzata M; Wdowin, Magdalena

    2015-06-01

    Rare earth elements (REE) have been recognised as critical raw materials, crucial for many clean technologies. As the gap between their global demand and supply increases, the search for their alternative resources becomes more and more important, especially for the countries which depend highly on their import. Coal fly ash (CFA), which when not utilised is considered waste, has been regarded as the possible source of many elements, including REE. Due to the increase in the energy demand, CFA production is expected to grow, making research into the use of this material a necessity. As Poland is the second biggest coal consumer in the European Union, the authors have studied different coal fly ashes from ten Polish power plants for their rare earth element content. All the fly ashes have a broadly similar distribution of rear earth elements, with light REE being dominant. Most of the samples have REE content relatively high and according to Seredin and Dai (Int J Coal Geol 94: 67-93, 2012) classification can be considered promising REE raw materials. PMID:25613802

  8. Hierarchical zeolites from class F coal fly ash

    Science.gov (United States)

    Chitta, Pallavi

    Fly ash, a coal combustion byproduct is classified as types class C and class F. Class C fly ash is traditionally recycled for concrete applications and Class F fly ash often disposed in landfills. Class F poses an environmental hazard due to disposal and leaching of heavy metals into ground water and is important to be recycled in order to mitigate the environmental challenges. A major recycling option is to reuse the fly ash as a low-cost raw material for the production of crystalline zeolites, which serve as catalysts, detergents and adsorbents in the chemical industry. Most of the prior literature of fly ash conversion to zeolites does not focus on creating high zeolite surface area zeolites specifically with hierarchical pore structure, which are very important properties in developing a heterogeneous catalyst for catalysis applications. This research work aids in the development of an economical process for the synthesis of high surface area hierarchical zeolites from class F coal fly ash. In this work, synthesis of zeolites from fly ash using classic hydrothermal treatment approach and fusion pretreatment approach were examined. The fusion pretreatment method led to higher extent of dissolution of silica from quartz and mullite phases, which in turn led to higher surface area and pore size of the zeolite. A qualitative kinetic model developed here attributes the difference in silica content to Si/Al ratio of the beginning fraction of fly ash. At near ambient crystallization temperatures and longer crystallization times, the zeolite formed is a hierarchical faujasite with high surface area of at least 360 m2/g. This work enables the large scale recycling of class F coal fly ash to produce zeolites and mitigate environmental concerns. Design of experiments was used to predict surface area and pore sizes of zeolites - thus obviating the need for intense experimentation. The hierarchical zeolite catalyst supports tested for CO2 conversion, yielded hydrocarbons up to C9, a performance attesting the hierarchal pore structure. The preliminary techno-economic feasibility assessment demonstrates a net energy saving of 75% and cost saving of 63% compared to the commercial zeolite manufacturing process.

  9. Effect of coal ash disposal upon an unconfined alluvial system

    International Nuclear Information System (INIS)

    Fly and bottom ash from coal combustion has been disposed in four ash ponds in an alluvial valley. Three of the ash ponds are receiving ash and one was filled and closed. Twenty eight monitoring wells ranging in depth from 10 feet to 65 feet have been installed at the site to study groundwater flow and chemistry. Hydraulic heads are influenced by the stage of the Kentucky River, and the flow direction is vertical below the ash ponds and predominantly horizontal a short distance from the pond all the way to the river. Three different groundwater flow zones were observed and have unique water chemistry. The deep zone (near bedrock) has a low Eh ( 100) and lower concentrations of Fe and ammonia nitrogen, median sulfate concentration (114 mg/l), and arsenic is below detection limits. The shallow groundwater zone is through the closed out ash point and has higher concentrations of nearly all cations and anions, including sulfate (888 mg/l) and arsenic (exists as arsenite) at concentration of 0.9 mg/l, low Eh (< -100), and high pH. When shallow flow enters the alluvium, the sulfate are attenuated by sulfate reduction and this results in high bicarbonate values. Saturation indices (SI) as calculated by the geochemical model, MINTEQA2, indicate that deep and intermediate groundwater are unsaturated and shallow groundwater is at or near equilibrium with respect to calcite, dolomite, and gypsum

  10. Adsorption of herbicides on coal fly ash from aqueous solutions.

    Science.gov (United States)

    Singh, Neera

    2009-08-30

    Development of low cost adsorbent for pesticide retention is an important area of research in environmental sciences. The present study reports the sorption potential of coal fly ash, a waste from power stations, for removal of metribuzin, metolachlor and atrazine from water. Batch sorption method was used to study the sorption of herbicides from water. The amount of herbicides sorbed increased with increase in the amount of fly ash in the suspension. The maximum capacity of the fly ash to adsorb metribuzin, metolachlor and atrazine was found to be 0.20, 0.28 and 0.38 mg/g by Freundlich equation and 0.56, 1.0 and 3.33 mg/g by Langmuir equation. Freundlich adsorption equation better explained the results of herbicides sorption in fly ash as regression coefficient (R(2)) values were higher from Freundlich equation than the Langmuir equation. Adsorption isotherms were L-type suggesting that the herbicide sorption efficiency of fly ash depend on the initial concentration of herbicide in the solution and maximum removal of herbicide was observed at concentrations less than 10 microg/ml. The results of this study have implications in using the fly ash for removal of these herbicides from industrial and agricultural waste water and can find use as a material in the preparation of biobeds to minimize environmental contamination from pesticide use. PMID:19269091

  11. Reuse of ash coal in the formulation of mortars

    International Nuclear Information System (INIS)

    This paper aims to study the ash incorporation from the combustion of coal in fluidized bed boilers, in production of mortar, replacing part of cement. Specimens were prepared using Portland cement to the specifications CPII-E-32 of normal characteristics and classification of sand below 100 mesh. Blends in the 4:1 ratio, that is, 4 parts of aggregate to 1 part of cement, with insertion of ashes in the proportions 0, 10, 20, 30, 40 and 50%. The mortar was developed in mixing and casting was made in a mold of 5 cm x 10 cm. The behavior of compressive strength was evaluated after 28 days; the strength decreases with increasing percentage of ash. Additional analysis was carried out by X-ray diffraction, and it was found that the substitution of this waste can be successfully used in mortars with blends of up to 30%. (author)

  12. Mineralogy and chemistry of conventional and fluidised bed coal ashes

    Directory of Open Access Journals (Sweden)

    Sulovský P

    2002-03-01

    Full Text Available Coal combustion residues represent very abundant inorganic waste materials. The change from conventional combustion of powdered North Bohemian brown coal to its combustion in fluidised bed boilers in several Czech power and heating plants calls for detailed mineralogical and geochemical characterisation of the combustion residues. The main differences between fly ashes from both combustion systems result from different burning temperatures and differing systems of desulphurisation (coeval with combustion / post-combustion. Both these factors influence the chemical and phase compositions as well as the speciation of trace elements. The study further shows that the validity of the surface enrichment model (Linton et al. 1975 can be limited.

  13. JV Task 6 - Coal Ash Resources Research Consortium Research

    Energy Technology Data Exchange (ETDEWEB)

    Debra Pflughoeft-Hassett; Tera Buckley; Bruce Dockter; Kurt Eylands; David Hassett; Loreal Heebink; Erick Zacher

    2008-04-01

    The Coal Ash Resources Research Consortium{reg_sign} (CARRC{reg_sign}, pronounced 'cars') focuses on performing fundamental and applied scientific and engineering research emphasizing the environmentally safe, economical use of coal combustion by-products (CCBs). CARRC member organizations, which include utilities and marketers, are key to developing industry-driven research in the area of CCB utilization and ensuring its successful application. The U.S. Department of Energy is a partner in CARRC through the EERC Jointly Sponsored Research Program (JSRP), which provides matching funds for industrial member contributions and facilitates an increased level of effort in CARRC. CARRC tasks were designed to provide information on CCB performance, including environmental performance, engineering performance, favorable economics, and improved life cycle of products and projects. CARRC technical research tasks are developed based on member input and prioritization. CARRC special projects are developed with members and nonmembers to provide similar information and to support activities, including the assembly and interpretation of data, support for standards development and technology transfer, and facilitating product development and testing. CARRC activities from 1998 to 2007 included a range of research tasks, with primary work performed in laboratory tasks developed to answer specific questions or evaluate important fundamental properties of CCBs. CARRC topical reports were prepared on several completed tasks. Specific CARRC 1998B2007 accomplishments included: (1) Development of several ASTM International Standard Guides for CCB utilization applications. (2) Organization and presentation of training courses for CCB professionals and teachers. (3) Development of online resources including the Coal Ash Resource Center, Ash from Biomass in Coal (ABC) of cocombustion ash characteristics, and the Buyer's Guide to Coal-Ash Containing Products. In addition, development of expanded information on the environmental performance of CCBs in utilization settings included the following: (1) Development of information on physical properties and engineering performance for concrete, soil-ash blends, and other products. (2) Training of students through participation in CARRC research projects. (3) Participation in a variety of local, national, and international technical meetings, symposia, and conferences by presenting and publishing CCB-related papers.

  14. Radioactivity of coals and ash and slag wastes at coal-fired thermal power plants

    Science.gov (United States)

    Krylov, D. A.; Sidorova, G. P.

    2013-04-01

    This paper presents an analysis of published data on the content of radioactive nuclides in coals originating from various coal deposits, and in ash and slag wastes produced at coal-fired thermal power plants, as well as in fly ash emitted from thermal power plants into the atmosphere. Problems related to the use of coals with an elevated content of natural radionuclides (NRNs) and methods of their solution implemented at the Urtuyskoe coalfield are dealt with. Data on the analysis of Transbaikal coals for the NRN content, as well as weighted mean content of uranium and thorium in coals from the Siberian Region, are given. In order to reduce irradiation of plant personnel and the population of the areas where coal producers and coal-fired thermal power plants are located, it is necessary to organize very careful control of the NRN content in both coals and products of their combustion that are released into the environment. To solve the problem related to the control of radioactivity, the centralized approach and creation of a proper normative base are needed. Experience gained in developing the Urtuyskoe coalfield shows that it is possible to create an efficient system of coal quality control with respect to the radiation hygiene factor and provide protection of the environment and health of the population.

  15. Thermal expansion of slag and fly ash from coal gasification

    OpenAIRE

    Aineto, Mónica; Acosta, Anselmo; Rincón López, Jesús María; Romero, Maximina

    2006-01-01

    Integrated gasification in combined cycle (IGCC) is an electrical power generation system, which is characterized to be a clean coal technology different than conventional process in combustible treatment. IGCC process gives rise to inorganic solid wastes in the form of vitreous slag and fly ashes with singular thermal properties. The gasification of the fuel takes place at high temperature and pressure in reducing atmosphere. Under those conditions, gases such as H2, N2 or CO, which are the ...

  16. Solidification of municipal wastes incinerated residues by using coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, J. [CERCHAR, Mazingarbe (France)

    1999-07-01

    FBC is now widely used to burn low quality coals because of its ability to meet environmental regulations, especially where CO{sub 2} emissions are of concern. The technology is also promising for a number of other fuels, especially those having high chloride contents. The characteristics of any fuel depend strongly on the combustion technique and temperature. Thus, one would expect FBC ashes to be substantially different from ashes from conventional incinerators. This study looks at the characteristics of ashes (Municipal Waste Incineration Residues - MWIR) from municipal wastes, originated from various cities in Europe, and incinerated in FBC and classifical grate furnace facilities. Information is also provide on the heavy metal contents and leaching characteristics of the various MW1 residues. All the results are examined in light of possible utilization strategies and landfill regulations regarding the potential for co-disposal of incinerator ashes with coal derived residues from FBC boilers to render the monoliths inert and resistant against hazardous events that amy occurred during ultimate and definitive storage. 5 refs., 2 figs., 15 tabs.

  17. Mullitization of black coal fly ashes

    OpenAIRE

    Mária Kušnierová; Mária Praš?áková; Dalibor Matýsek; Vladimír ?ablík

    2011-01-01

    In this paper are presented the results of experiments focused on the study of thermal treatment influence of selected black coal flyashes from the heating plant in Kosice and the power plant in Vojany. The study was realized with original not pretreated samples.The obtained results confirmed that after the thermal treatment of both samples the phase’s change of material occurred. At 1050 °C,the decrease of amorphous phase was remarked, being transformed to the mullite and spinel. This inform...

  18. Evaluation and Treatment of Coal Fly Ash for Adsorption Application

    Directory of Open Access Journals (Sweden)

    Samson Oluwaseyi BADA

    Full Text Available Many researchers had investigated fly ash as an adsorbent for the uptake of organic compounds from petrochemical waste effluents. The availability, inexpensive and its adsorption characteristic had made it an alternative media for the removal of organic compounds from aqueous solution. The physical property of South African Coal Fly Ash (SACFA was investigated to determine its adsorption capability and how it can be improved. Chemical treatment using 1M HCl solution in the ratio of (1 g fly ash to (2 ml of acid was used and compared with untreated heat-treated samples. The chemically treated fly ash has a higher specific surface area of 5.4116 m2/g than the heat-treated fly ash with 2.9969 m2/g. More attention had to be given to the utilization of SACFA for the treatment of wastewaters containing organic compounds through the application of Liquid phase adsorption process that was considered as an inexpensive and environmentally friendly technology.

  19. Water Retention Characteristics of Porous Ceramics Produced from Waste Diatomite and Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Kae-Long Lin

    2013-07-01

    Full Text Available This study examines potential waste diatomite and coal fly ash reuse to prepare water absorption and retain porous ceramics. The operating conditions are constant pressure (5 MPa, sintering temperature (1000-1270°C, sintering time (2 h, waste diatomite containing coal fly ash at different proportions (0-20%, respectively. The porous ceramic samples containing coal fly ash show low thermal conductivity properties (0.278-0.349 W/mK, probably owing to the more pores than those in the concrete (1.458 W/mK. Water release (t1/2 value by the porous ceramic samples is decelerated by porous ceramic samples containing coal fly ash, due to the synergy effect of high water absorption by the coal fly ash and better than in the foamed glass material (4 h. Porous ceramic samples containing coal fly ash is highly promising for use in water absorption and retention applications.

  20. Low-level radiation in coals utilized and ashes produced at New York State electric utilities

    International Nuclear Information System (INIS)

    Eight coal-fired power plants in New York State were sampled for coal, fly ash and bottom ash. Samples were analyzed for uranium 238, uranium 235, uranium 234, thorium 232, thorium 230, radium 226, lead 210, polonium 210, radon 222. The leachate of six fly ash samples was analyzed for all of the above except radon 222. Some data on fly ash analysis are included

  1. Recycling of after-extraction-residues and fly ash through composting for amelioration of alkaline soil

    Energy Technology Data Exchange (ETDEWEB)

    Kumbhar, P.P.; Patil, Y.M.; Chavan, C.D. [and others] [North Maharashtra University, Jalgaon (India). School of Chemical Sciences

    2002-07-01

    Indiscriminate use of fertilizers and pesticides has transformed large areas of agriculturally fertile soils into alkaline soils. The paper discusses the feasibility of using after-extraction residues (AER) and fly ash for amelioration of alkali soils. The paper suggests that if AER and fly ash are added to the soil after preparing their composts in varying proportions, instead of being directly added to the soil, this will help improve soil texture, fertility and thus, the yield of agricultural produce. 8 refs., 4 tabs.

  2. Water Retention Characteristics of Porous Ceramics Produced from Waste Diatomite and Coal Fly Ash

    OpenAIRE

    Kae-Long Lin; Ju-Ying Lan

    2013-01-01

    This study examines potential waste diatomite and coal fly ash reuse to prepare water absorption and retain porous ceramics. The operating conditions are constant pressure (5 MPa), sintering temperature (1000-1270°C), sintering time (2 h), waste diatomite containing coal fly ash at different proportions (0-20%), respectively. The porous ceramic samples containing coal fly ash show low thermal conductivity properties (0.278-0.349 W/mK), probably owing to the more pores than those in the concre...

  3. Coal-ash Corrosion of Alloys for Combustion Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Purohit, A.; Rink, D.L.

    2003-04-22

    A program on coal-ash corrosion is being conducted at Argonne National Laboratory to evaluate the performance of several structural alloys in the presence of mixtures of synthetic coal ash, alkali sulfates, and alkali chlorides. Candidate alloys are also exposed in a small-scale coal-fired combustor at the National Energy Technology Laboratory in Pittsburgh. Experiments in the present program, which addresses the effects of deposit chemistry, temperature, and alloy chemistry on the corrosion response of alloys, were conducted at temperatures in the range of 575-800 C for time periods up to {approx}1850 h. Fe-base alloys selected for the study included HR3C, 310TaN, HR120, SAVE 25, NF709, modified 800, 347HFG, and HCM12A. In addition, 800H clad with Alloy 671 was included in several of the exposures. Ni-base alloys selected for the study included 600, 601, 617, 690, 625, 602CA, 214, 230, 45TM, HR 160, and 693. Data were obtained on weight change, scale thickness, internal penetration, microstructural characteristics of corrosion products, mechanical integrity of the scales, and cracking of scales. Results showed that the relationship of corrosion rates to temperature followed a bell-shaped curve for Fe-base alloys, with peak rates at {approx}725 C, but the rate itself was dependent on the alloy chemistry. Several Fe-base alloys showed acceptable rates in the sulfate-containing coal-ash environment; but NaCl in the deposit led to catastrophic corrosion at 650 and 800 C. Ni-base alloys generally exhibited less corrosion than the Fe-base alloys under similar exposure conditions; however, they were susceptible to localized corrosion in the form of pits.

  4. Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

    OpenAIRE

    Nabih K; Kada M.K.; Hmiri M.; Hamsi N.

    2014-01-01

    We focused our research on recycling industrial wastes, fly ash (F.A), bottom ash (B.A) and oil shale ash (S.A) in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class...

  5. Material and structural characterization of alkali activated low-calcium brown coal fly ash

    International Nuclear Information System (INIS)

    The waste low-calcium Czech brown coal fly ash represents a considerable environmental burden due to the quantities produced and the potentially high content of leachable heavy metals. The heterogeneous microstucture of the geopolymer Mn [-(Si-O)z-Al-O]n.wH2O, that forms during the alkaline activation, was examined by means of microcalorimetry, XRD, TGA, DSC, MIP, FTIR, NMR MAS (29Si, 27Al, 23Na), ESEM, EDS, and EBSD. The leaching of heavy metals and the evolution of compressive strength were also monitored. The analysis of raw fly ash identified a number of different morphologies, unequal distribution of elements, Fe-rich rim, high internal porosity, and minor crystalline phases of mullite and quartz. Microcalorimetry revealed exothermic reactions with dependence on the activator alkalinity. The activation energy of the geopolymerization process was determined as 86.2 kJ/mol. The X-ray diffraction analysis revealed no additional crystalline phases associated with geopolymer formation. Over several weeks, the 29Si NMR spectrum testified a high degree of polymerization and Al penetration into the SiO4 tetrahedra. The 23Na NMR MAS spectrum hypothesized that sodium is bound in the form of Na(H2O)n rather than Na+, thus causing efflorescence in a moisture-gradient environment. As and Cr6+ are weakly bonded in the geopolymer matrix, while excellent immobilization of Zn2+, Cu2+, Cd2+, and Cr3+ are reported.

  6. Material and structural characterization of alkali activated low-calcium brown coal fly ash.

    Science.gov (United States)

    Skvára, Frantisek; Kopecký, Lubomír; Smilauer, Vít; Bittnar, Zdenek

    2009-09-15

    The waste low-calcium Czech brown coal fly ash represents a considerable environmental burden due to the quantities produced and the potentially high content of leachable heavy metals. The heterogeneous microstucture of the geopolymer M(n) [-(Si-O)(z)-Al-O](n).wH(2)O, that forms during the alkaline activation, was examined by means of microcalorimetry, XRD, TGA, DSC, MIP, FTIR, NMR MAS ((29)Si, (27)Al, (23)Na), ESEM, EDS, and EBSD. The leaching of heavy metals and the evolution of compressive strength were also monitored. The analysis of raw fly ash identified a number of different morphologies, unequal distribution of elements, Fe-rich rim, high internal porosity, and minor crystalline phases of mullite and quartz. Microcalorimetry revealed exothermic reactions with dependence on the activator alkalinity. The activation energy of the geopolymerization process was determined as 86.2kJ/mol. The X-ray diffraction analysis revealed no additional crystalline phases associated with geopolymer formation. Over several weeks, the (29)Si NMR spectrum testified a high degree of polymerization and Al penetration into the SiO(4) tetrahedra. The (23)Na NMR MAS spectrum hypothesized that sodium is bound in the form of Na(H(2)O)(n) rather than Na(+), thus causing efflorescence in a moisture-gradient environment. As and Cr(6+) are weakly bonded in the geopolymer matrix, while excellent immobilization of Zn(2+), Cu(2+), Cd(2+), and Cr(3+) are reported. PMID:19303704

  7. Transformation of primary and secondary raw materials in zeolite containing products. Pt. 4. About the reactivity of the brown coal filter ash from the power plant Hagenwerder

    Energy Technology Data Exchange (ETDEWEB)

    Bergk, K.H.; Porsch, M.; Wolf, F.

    1986-11-01

    By a combination of acidic and alkaline treatments of the brown coal filter ash Hagenwerder it was tried to get informations about the reactivity of the different Al/sub 2/O/sub 3/ components. It was possible to obtain zeolite A-, zeolite P- and hydroxylsodalite-containing products from the solid residue of HCl treatment in a hydrothermal reaction with additional NaOH. In connection with results of zeolite formation from the untreated filter ash it was possible to estimate the content of metakaoline and mullite of the Hagenwerder filter ash.

  8. Remediação de drenagem ácida de mina usando zeólitas sintetizadas a partir de cinzas leves de carvão Remediation of acid mine drainage using zeolites synthesized from coal fly ash

    Directory of Open Access Journals (Sweden)

    Denise Alves Fungaro

    2006-07-01

    Full Text Available Zeolitic material was synthesized from coal fly ashes (baghouse filter fly ash and cyclone filter fly ash by hydrothermal alkaline activation. The potential application of the zeolitic product for decontamination of waters from acid mine drainage was evaluated. The results showed that a dose of 30 g L-1 of zeolitic material allowed the water to reach acceptable quality levels after treatment. Both precipitation and cation-exchange processes accounted for the reduction in the pollutant concentration in the treated waters.

  9. Remediação de drenagem ácida de mina usando zeólitas sintetizadas a partir de cinzas leves de carvão / Remediation of acid mine drainage using zeolites synthesized from coal fly ash

    Scientific Electronic Library Online (English)

    Denise Alves, Fungaro; Juliana de Carvalho, Izidoro.

    2006-07-01

    Full Text Available [...] Abstract in english Zeolitic material was synthesized from coal fly ashes (baghouse filter fly ash and cyclone filter fly ash) by hydrothermal alkaline activation. The potential application of the zeolitic product for decontamination of waters from acid mine drainage was evaluated. The results showed that a dose of 30 [...] g L-1 of zeolitic material allowed the water to reach acceptable quality levels after treatment. Both precipitation and cation-exchange processes accounted for the reduction in the pollutant concentration in the treated waters.

  10. Effect of coal ash on sonochemical degradation of phenol in water.

    Science.gov (United States)

    Nakui, H; Okitsu, K; Maeda, Y; Nishimura, R

    2007-02-01

    The influences of coal ash on the degradation of phenol in water were investigated under the stirring or ultrasonic irradiation conditions. Phenol solution (10mg/L, 100mL) was sonicated at 200 kHz and 200 W with or without coal ash (53-106 microm in particle size and concentration of 0.0-1.5 wt%). It was found that the sonochemical degradation of phenol in the presence of coal ash was faster than that in the absence of coal ash, and the optimum amount of coal ash was a maximum at 0.4-0.6 wt%. It was confirmed that the phenol degradation did not occur by the addition of hydrogen peroxide and nitric acid under the stirring conditions. The sonochemical degradation with coal ash was depressed by the addition of tertiary butyl alcohol as a radical scavenger. These results indicated that the coal ash accelerated the phenol degradation due to the increase in the amount of hydroxyl radicals under the ultrasonic irradiation. Since the coal ash used had a porous and uneven surface, which was observed by SEM, it was assumed that the coal ash led to the increase in the nucleation site for cavitation bubble due to its surface roughness. PMID:16737837

  11. Behavior of aluminum complexes in the altered coal and low temperature coal ashes.

    Czech Academy of Sciences Publication Activity Database

    Straka, Pavel

    2010-01-01

    Ro?. 7, ?. 4 (2010), s. 461-467. ISSN 1214-9705 R&D Projects: GA AV ?R IAA300460702 Institutional research plan: CEZ:AV0Z30460519 Keywords : aluminum complexes * altered coal * ash Subject RIV: DD - Geochemistry Impact factor: 0.452, year: 2010 www.irsm.cas.cz/?Lang=CZE&Menu=25,29,0,0

  12. The Use of Coal Bottom Ash In Hot Mix Asphalt

    Directory of Open Access Journals (Sweden)

    Charles Begyina Kodjo Nketsiah

    2015-05-01

    Full Text Available Bottom ash is a waste material from coal burnt to generate electric power. It is incombustible and non-biodegradable; hence, the best way to dispose it is by recycling rather than incineration and land filling. Past research on bottom ash in road building have focused mainly on embankment filling, sub-base and base courses; except boiler slag which has received much attention in Hot Mix Asphalt (HMA. Bottom ash from Tanjung Bin Power Station was thus investigated through laboratory testing to justify its use in HMA construction in Malaysia. This Paper analysed the data with regards to performance in HMA. In the Marshall Mix design, the material largely satisfied the Stability, Flow and Stiffness requirements which were comparable to that of conventional aggregates, although void contents were a bit higher. When blended with granite, all the parameters were met. Contrary to past suggestions that bottom ash in HMA consumes more bitumen, the 6.4% (51.20g Optimum Bitumen Content (OBC achieved in this study does not necessarily translate into high consumption, compared to OBC of 5.3% (59.63g in the case of granite. The HMA also proved to be highly resistant to moisture-induced damage and satisfied the minimum JKR specification for Static Uniaxial Load Strain. Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4  

  13. Investigation of the potential of coal combustion fly ash for mineral sequestration of CO2 by accelerated carbonation

    International Nuclear Information System (INIS)

    Mineral carbonation of alkaline waste materials is being studied extensively for its potential as a way of reducing the increased level of CO2 in the atmosphere. Carbonation converts CO2 into minerals which are stable over geological time scales. This process occurs naturally but slowly, and needs to be accelerated to offset the present rate of emissions from power plants and other emission sources. The present study attempts to identify the potential of coal fly ash as a source for carbon storage (sequestration) through ex-situ accelerated mineral carbonation. In the study, two operational parameters that could affect the reaction process were tested to investigate their effect on mineralization. Coal fly ash was mixed with water to different water-to-solid ratios and samples were carbonated in a pressure vessel at different initial CO2 pressures. Temperature was kept constant at 40 °C. According to the results, one ton of Hazelwood fly ash could sequester 7.66 kg of CO2. The pressure of CO2 inside the vessel has an effect on the rate of CO2 uptake and the water-to-solid ratio affects the weight gain after the carbonation of fly ash. The results confirm the possibility of the manipulation of process parameters in enhancing the carbonation reaction. - Highlights: ? Mineral sequestration CO2 by of coal fly ash is a slow process under ambient conditions. ? It can be accelerated by manipulating the process parameters inside a reactor. ? Initial CO2 pressure and water to solid mixing ratio inside the reactor are two of those operational parameters. ? According to the test results higher CO2 initial pressure gives higher on rates of CO2 sequestration. ? Water to fly ash mixing ratio effect on amount of CO2 sequestered into fly ash

  14. Prevention of trace and major element leaching from coal combustion products by hydrothermally-treated coal ash

    Energy Technology Data Exchange (ETDEWEB)

    Adnadjevic, B.; Popovic, A.; Mikasinovic, B. [University of Belgrade, Belgrade (Serbia). Dept. of Chemistry

    2009-07-01

    The most important structural components of coal ash obtained by coal combustion in 'Nikola Tesla A' power plant located near Belgrade (Serbia) are amorphous alumosilicate, alpha-quartz, and mullite. The phase composition of coal ash can be altered to obtain zeolite type NaA that crystallizes in a narrow crystallization field (SiO{sub 2}/Al{sub 2}O{sub 3}; Na{sub 2}O/SiO{sub 2}; H{sub 2}O/Na{sub 2}O ratios). Basic properties (crystallization degree, chemical composition, the energy of activation) of obtained zeolites were established. Coal ash extracts treated with obtained ion-exchange material showed that zeolites obtained from coal ash were able to reduce the amounts of iron, chromium, nickel, zinc, copper, lead, and manganese in ash extracts, thus proving its potential in preventing pollution from dump effluent waters.

  15. Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

    Directory of Open Access Journals (Sweden)

    Nabih K.

    2014-04-01

    Full Text Available We focused our research on recycling industrial wastes, fly ash (F.A, bottom ash (B.A and oil shale ash (S.A in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class C and possesses hydraulic and poozolanic properties. The crystalline phases constituting each ash were analysed by XRD. We observe in bottom ash the presence of quartz and mullite. The same crystals are found in fly ash with hematite and magnetite. Oil shale ash is composed of quartz, anhydrite, gehlenite, wollastonite and periclase. The microstructures of fly ash and bottom ash were studied using SEM. The bottom ash was composed respectively of fine particles that are generally irregularly shaped, their dimensions are between 5 and 28?m and of big particles(300 ?m. The EDX analysis coupled with an electronic microscope provided some information about the major elements that constitute our samples. The dehydrations of anhydrous and three days hydrated cement were examined by DSC. For hydrated cements we noticed endothermic peaks related to the dehydration of CSH, CH and decomposition of carbonates. The study of the mechanical properties of CPJ45 cement by adding different proportions of fly ash, bottom ash and oil shale ash helped clarifying the percentage of ash that leaded to improve the 28 days mechanical strength. The results show that the cements studied have their maximum mechanical resistance with the addition at 7% of fly ash or 10% of oil shale ash.

  16. Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer.

    Science.gov (United States)

    Chindaprasirt, Prinya; Rattanasak, Ubolluk

    2010-04-01

    In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na(2)SiO(3)) and 10M sodium hydroxide (NaOH) solutions at mass ratio of Na(2)SiO(3)/NaOH of 1.5 and curing temperature of 65 degrees C for 48h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers. PMID:19854038

  17. Utilization of blended fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash in geopolymer

    International Nuclear Information System (INIS)

    In this paper, synthesis of geopolymer from fluidized bed combustion (FBC) ash and pulverized coal combustion (PCC) fly ash was studied in order to effectively utilize both ashes. FBC-fly ash and bottom ash were inter-ground to three different finenesses. The ashes were mixed with as-received PCC-fly ash in various proportions and used as source material for synthesis of geopolymer. Sodium silicate (Na2SiO3) and 10 M sodium hydroxide (NaOH) solutions at mass ratio of Na2SiO3/NaOH of 1.5 and curing temperature of 65 deg. C for 48 h were used for making geopolymer. X-ray diffraction (XRD), scanning electron microscopy (SEM), degree of reaction, and thermal gravimetric analysis (TGA) were performed on the geopolymer pastes. Compressive strength was also tested on geopolymer mortars. The results show that high strength geopolymer mortars of 35.0-44.0 MPa can be produced using mixture of ground FBC ash and as-received PCC-fly ash. Fine FBC ash is more reactive and results in higher degree of reaction and higher strength geopolymer as compared to the use of coarser FBC ash. Grinding increases reactivity of ash by means of increasing surface area and the amount of reactive phase of the ash. In addition, the packing effect due to fine particles also contributed to increase in strength of geopolymers.

  18. Utilization of coal ash contributing to environment and power reduction. Sekitanbai no kankyo koken riyo to doryoku setsugen riyo no bun prime ya

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, M.. (Electric Power Development Co. Ltd., Tokyo (Japan))

    1991-09-30

    Some techniques relating to the contribution to surrounding environment and power reduction of utilizing techniques of coal ash which is produced at the rate of 500,000,000 tons/year in this world are explained. Almost all coal ash produced in Japan originates from pulverized coal firing and the utilizing areas are as follows: (1) resource preserving area including the application to the asphalt filler; (2) product substituting area including the cement substitution; (3) industrial waste processing area including the deodorant; (4) mixing area with industrial waste including the recycling one after mixing with industrial waste and mixing with mud; (5) land planting area including soil improver and culture medium pelletized with industrial waste; and (6) seabed planting area including the surface lining on sludge area in seabed. Further, the effective cases of representative applications are as follows: When coal ash is used as the filler for asphalt concrete, the effect is raised by pulverizing coal ash followed by repressing to the filler form. When coal ash is used as the cement substitute, the concrete deterioration is prevented by suppressing the alkaline aggregate reaction. 5 refs.. 5 figs., 1 tab.

  19. Mosses accumulate heavy metals from the substrata of coal ash

    Directory of Open Access Journals (Sweden)

    Vukojevi? Vanja

    2005-01-01

    Full Text Available Plants that are able to accumulate and tolerate extraordinarily high concentrations of heavy metals (hyperaccumulators can be used for phytoremediation (removal of contaminants from soils or phytomining (growing a crop of plants to harvest the metals. Two moss species, Bryum capillare Hedw. and Ceratodon purpureus Hedw., were tested as potential phytoremedies under in vivo conditions on a coal ash disposal site in the surroundings of Obrenovac (NW Serbia. The content of various heavy metals (iron, manganese zinc, lead, nickel, cadmium, and copper in the mosses and substrata were investigated over a period of three years. Iron and zinc were found to have the highest concentration in the mosses.

  20. Analysis of natural radionuclides in coal, slag and ash in coal-fired power plants in Serbia

    OpenAIRE

    Jankovi? M.M.; Todorovi? D.J.; Nikoli? J.D.

    2011-01-01

    The radioactivity monitoring in the “Nikola Tesla”, “Kolubara”, “Morava” and “Kostolac” coal-fired power plants was performed by the Radiation and Environmental Protection Laboratory, Vin?a Institute of nuclear sciences in the period 2003-2010. Monitoring included the analysis of soil, water, flying ash, slag, coal and plants. This paper presents the results of the radioactivity analysis of coal, ash and slag samples. Naturally occurring radionuclides 226Ra, 232Th, 40K, 235U, 238U, and ...

  1. Radon and thoron flux densities from some of NSW coal ash dams

    International Nuclear Information System (INIS)

    The use of coal as an energy source can cause some potential environmental and human health hazards associated with radionuclides mobilized by the coal fuel cycle. The objective of this study was to assess environmental significance of radon and thoron emissions from New South Wales coal ash storage dams operated by Pacific Power. To achieve this objective radon and thoron flux densities were measured from selected ash dams and mine spoil areas. It was found that: (i) ash dams currently in operation exhibit significantly lower flux densities than average values for Australian soils, and (ii ash dams under rehabilitation and mine spoils have flux densities comparable to Australian soil. 18 refs., 2 tabs

  2. Uranium extraction from the waste ash after burning the Mongolian coal

    International Nuclear Information System (INIS)

    The content of natural radionuclides, as well as possibility of uranium leaching from the brown coal ash of the Mongolian Thermal Power Plant, was determined. Instrumental Gamma Activation Analysis (IGAA) and X-Ray Fluorescence Analysis (RFA) for determination of the element contents were used. Leaching of uranium from the brown coal ash was carried out by the 8 M HNO3+HF (10%) mixture. Extraction of uranium from solution and separation from contiguous elements were carried out by ion-exchange resin. The natural radioelements 238U, 232Th and products of their decay were absent in the ash sample after leaching, which allows using the brown coal ash as building material

  3. Mineralogy and microstructure of sintered lignite coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Marina Ilic; Christopher Cheeseman; Christopher Sollars; Jonathan Knight [Faculty of Technology and Metallurgy, Belgrade (Yugoslavia)

    2003-02-01

    Lignite coal fly ash from the 'Nikola Tesla' power plant in Yugoslavia has been characterised, milled, compacted and sintered to form monolithic ceramic materials. The effect of firing at temperatures between 1130 and 1190{sup o}C on the density, water accessible porosity, mineralogy and microstructure of sintered samples is reported. This class C fly ash has an initial average particle size of 82 {mu}m and contains siliceous glass together with the crystalline phases quartz, anorthite, gehlenite, hematite and mullite. Milling the ash to an average particle size of 5.6 m, compacting and firing at 1170{sup o}C for 1 h produces materials with densities similar to clay-based ceramics that exhibit low water absorption. Sintering reduces the amount of glass, quartz, gehlenite and anhydrite, but increases formation of anorthite, mullite, hematite and cristobalite. SEM confirms the formation of a dense ceramic at 1170{sup o}C and indicates that pyroplastic effects cause pore formation and bloating at 1190{sup o}C. 23 refs., 6 figs., 2 tabs.

  4. Potential trace element emissions from the gasification of Illinois coals. [Duplicate determinations of 34 elements in coal and ash samples

    Energy Technology Data Exchange (ETDEWEB)

    Sather, N. F.; Swift, W. M.; Jones, J. R.; Beckner, J. L.; Addington, J. H.; Wilburn, R. L.

    1975-03-01

    Results of comprehensive trace element analyses of samples of Illinois No. 5 and No. 6 seam coals and the unquenched ashes obtained from gasification of these coals in a Lurgi reactor are reported and discussed. Areas where additional background information is needed for assessment of the environmental impact of trace element emissions from coal gasification are identified. (auth)

  5. JV Task 120 - Coal Ash Resources Research Consortium Research

    Energy Technology Data Exchange (ETDEWEB)

    Debra Pflughoeft-Hassett; Loreal Heebink; David Hassett; Bruce Dockter; Kurt Eylands; Tera Buckley; Erick Zacher

    2009-03-28

    The Coal Ash Resources Research Consortium{reg_sign} (CARRC{reg_sign}, pronounced 'cars') is the core coal combustion product (CCP) research group at the Energy & Environmental Research Center (EERC). CARRC focuses on performing fundamental and applied scientific and engineering research emphasizing the environmentally safe, economical use of CCPs. CARRC member organizations, which include utilities and marketers, are key to developing industry-driven research in the area of CCP utilization and ensuring its successful application. The U.S. Department of Energy is a partner in CARRC through the EERC Jointly Sponsored Research Program, which provides matching funds for industrial member contributions and facilitates an increased level of effort in CARRC. CARRC tasks were designed to provide information on CCP performance, including environmental performance, engineering performance, favorable economics, and improved life cycle of products and projects. CARRC technical research tasks are developed based on member input and prioritization. CARRC special projects are developed with members and nonmembers to provide similar information and to support activities, including the assembly and interpretation of data, support for standards development and technology transfer, and facilitating product development and testing. CARRC activities from 2007 to 2009 included a range of research tasks, with primary work performed in laboratory tasks developed to answer specific questions or evaluate important fundamental properties of CCPs. The tasks were included in four categories: (1) Environmental Evaluations of CCPs; (2) Evaluation of Impacts on CCPs from Emission Controls; (3) Construction and Product-Related Activities; and (4) Technology Transfer and Maintenance Tasks. All tasks are designed to work toward achieving the CARRC overall goal and supporting objectives. The various tasks are coordinated in order to provide broad and useful technical data for CARRC members. Special projects provide an opportunity for non-CARRC members to sponsor specific research or technology transfer consistent with CARRC goals. This report covers CARRC activities from January 2007 through March 2009. These activities have been reported in CARRC Annual Reports and in member meetings over the past 2 years. CARRC continues to work with industry and various government agencies with its research, development, demonstration, and promotional activities nearing completion at the time of submission of this report. CARRC expects to continue its service to the coal ash industry in 2009 and beyond to work toward the common goal of advancing coal ash utilization by solving CCP-related technical issues and promoting the environmentally safe, technically sound, and economically viable management of these complex and changing materials.

  6. Radioactivity in coal, ashes and selected wastewaters from Canadian coal-fired steam electric generating stations

    International Nuclear Information System (INIS)

    Coal is known to contain naturally occurring radioactive elements and there has been speculation that as a results, coal-fuelled power generation stations may be significant emitters of these substances. In this report, the subject of radioactivity is introduced. The kinds of radioactive substances which occur naturally in coal formations, the nature of their emissions and the existing information on their behaviour and their effects on environmental organisms are also reviewed. The results of an examination of levels of alpha, beta and gamma radiaton levels, and the substances which produce them in coals, fly ashes, bottom ashes and related wastewaters at six Canadian coal-fuelled power stations are presented. Difficulties in studies of this nature and the potential effects of these releases on organisms in the adjacent aquatic environment are discussed. Existing and potential technologies for the removal of these substances from wastewaters are examined. In general the releases in wastewaters from the six stations were found to be lower than those known to cause short-term or acute biological effects. The potential for long-term effects from such low-level releases could not be accurately assessed because of the paucity of information. A number of recommendations for: improvements in further studies of this nature; the further examination of the fate of naturally occurring radionuclides in the environment; and the determination of the long-term effects of low levels of naturally occurring radioactive substances on aquatic organisms, are made

  7. Adsorption of indigo carmine from aqueous solution using coal fly ash and zeolite from fly ash

    International Nuclear Information System (INIS)

    Coal fly ash, a waste generated at the Figueira coal-fired electric power plant located in Brazil, was used to synthesize zeolite by hydrothermal treatment with NaOH solution at 100 deg C for 24 h. The fly ash (FA) and this synthesized zeolite (ZM) that was characterized predominantly as hydroxy-sodalite were used as adsorbents for anionic dye indigo carmine from aqueous solutions. The samples were analyzed by instrumental neutron activation analysis (INAA) for the determination of As, Co, Fe, La, Mo, Na, Sb, Sc, Sm, Th, U and Zn. Effects of contact time and initial dye concentration were evaluated in the adsorption processes. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism for both the adsorbents. The Langmuir isotherm model provided the best correlation of the experimental data. The maximum adsorption capacity was found to be 1.48 mg L-1 for FA and 1.23 mg L-1 for ZM. Laboratory leaching and solubilization tests conducted to classify this ZM as if was a waste residue according to the Brazilian regulation classified it as a residue non-hazardous and non-inert. (author)

  8. Studying the melting behavior of coal, biomass, and coal/biomass ash using viscosity and heated stage XRD data

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Folkedahl, B.

    2006-01-01

    The use of biomass for power generation can result in significant economical and environmental benefits. The greenhouse emissions can be reduced as well as the cost of the produced electricity. However, ash-related problems, including slagging, agglomeration, and corrosion, can cause frequent unscheduled shutdowns, decreasing the availability and increasing the cost of the produced power. In addition, the fouling of the heat exchange surfaces reduces the system efficiency. In this work the melting and rheological properties of various biomass and biomass/ coal ash samples were studied by using a high-temperature rotational viscometer and a hot stage XRD. The produced data were used to calculate the operating temperature of a pilot-scale entrained flow reactor during the cocombustion of biomass/ coal samples in order to ensure the slag flow and to avoid corrosion of the walls due to liquid slag/metal interaction. Biomass ash proved to have significantly different melting behavior compared to that of the coal ash. Furthermore, the addition of biomass to coal ash led to lower viscosity and subsequently to higher stickiness of the produced ash particles. The melting behavior of the slag generated by the cocombustion tests appeared to be somewhat different compared to that of the laboratory-prepared ash samples. The heated stage XRD data provide useful information regarding the reactions among the various ash compounds and the phase transformations during the heating and cooling of the ash samples and helped the explanation of the produced viscosity curves.

  9. Natural radioactivity of coal and fly ash at the Nikola Tesla B TPP

    Directory of Open Access Journals (Sweden)

    Kisi? Dragica M.

    2013-01-01

    Full Text Available Serbian thermal power plants (TPPs produce siliceous fly ash from lignite in the quantity of approximately 6 million tons per year. The potential market for the use of fly ash is operational, but for the time being, only used by cement producers. Fly ash radioactivity could be one of the major points of concern when larger use of fly ash is planned, particularly in the Serbian construction industry. Radioactivity measurements have been conducted regularly for decades. This paper presents the results of a ten-year fly ash radioactivity measurements at the Nikola Tesla B TPP located in Obrenovac. In addition, the paper compares the natural radionuclides coal content data combusted by the Nikola Tesla B TPP boilers coming from the Kolubara Basin and ash created during coal combustion. Fly ash created in the Nikola Tesla TPPs boilers is characterised by the increased concentration of the natural radionuclides content compared to coal. This is the so-called technologically enhanced natural radioactivity (Technologically Enhanced Occurring Radioactive Material - TENORM of industrial waste, whereas the average specific activities: 232Th in coal amount to 25.2 Bq/kg, and in fly ash and coal 84.2 Bq/kg and 238U 38.3 Bq/kg, respectively. Following the obtained natural radionuclides content results it may be concluded that the Nikola Tesla B TPP ash may be disposed into the environment. Ash may be used also in the construction industry (civil engineering. In building construction applications, ash share as the additive to other building materials depends from its physical and chemical characteristics, as well as from the radionuclides activity: 266Ra, 232Th and 40K. Unlike the thermal power plants regularly (once a year testing the specific natural radionuclides activity in the combusted coal and boiler fly ash, Electric Power Industry of Serbia has not performed large-scale investigations of the natural radionuclides content in coal within the Kolubara Mining Basin. Natural radionuclides content in fly ash is compared to the combusted coal some 3 - 4 times higher and may present a limitation for applying ash in the construction industry. In view of the above, and considering the construction industry interests in using the Nikola Tesla B TPP ash, regular investigations of the natural radionuclides content in ash created in the thermal power plants should be carried out, together with the Kolubara Mining Basin coal combusted by the Nikola Tesla B TPP and other PE EPS thermal power plants. The current Kolubara Mining Basin coal characteristics investigation programme should be supplemented by the natural radionuclides content of the uranium (238U, 226Ra and thorium series (232Th and potassium 40 (40K.

  10. Design and testing controlled low-strength materials (CLSM) using clean coal ash

    Energy Technology Data Exchange (ETDEWEB)

    Naik, T.R.; Kraus, R.N. [Univ. of Wisconsin, Milwaukee, WI (United States); Sturzl, R.F. [Manitowoc Public Utilities, WI (United States); Ramme, B.W. [Wisconsin Electric Power Co., Milwaukee, WI (United States)

    1998-10-01

    The major objective of this project was to develop mixture proportions for controlled low-strength material (CLSM) using clean coal ash obtained from atmospheric fluidized bed combustion (AFBC). A clean coal ash is defined as the ash derived from SO{sub x} and NO{sub x} control technologies. The specific ashes used for this project were: (1) circulating fluidized bed boiler fly ash and bottom ash and (2) stoker-type boiler fly ash and bottom ash. These two coal ash samples were characterized for physical and chemical properties. Chemical properties and water leaching tests were also performed on the hardened CLSM. Many initial CLSM mixtures were developed by blending the two types of ash. Tests conducted on the final three selected CLSM mixtures included compressive strength, bleeding, setting and hardening, settlement, length change of hardened CLSM, permeability, mineralogy, and chemical water leach testing. Results show that acceptable CLSM material can be developed by blending the fluidized bed boiler ash with the stoker boiler ash. Recommendations for a pilot scale manufacturing application of the three CLSM mixtures were made based upon the lab test results.

  11. Determination of radioactive trace elements in ashes and fly-ashes from Brazilian coal-fired power plants

    International Nuclear Information System (INIS)

    The aim of this work was to apply a epithermal neutron activation technique to determine the uranium and thorium content in coal ashes and fly ashes from Brazilian coal-fired thermoelectric plants and to evaluate the contribution of these elements and their descendents to the environmental radioactivity. Brazil has adopted as short term policy the use of alcohol and coal as alternative sources of energy. With regard to coal, large deposits of this mineral are found in southern states but the serious problem of its utilization is the risk of environmental contamination which can reach dangerous levels because the industrial plants burn several million tons per year. Uranium and thorium contents, determined experimentally, are extrapolated for annual coal consumption and their amounts and the activity of the radium isotopes descendents released to the atmosphere are calculated. The significance of these values and problems in environmental pollution are discussed

  12. Rheology of fly ashes from coal and biomass co-combustion

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Frandsen, Flemming

    2010-01-01

    The presence of large amounts of alkali metals, chlorine and sulphur in most biomass fuels - compared to coal - can create serious ash-related problems such as deposition, agglomeration and/or corrosion. This paper discusses the viscosity characteristics of fly ash from the co-combustion of various coal/biomass blends in a pilot scale pf-boiler. The produced data provide information on the melting of the ash and its flow characteristics, as a function of temperature, which may be used to modify the temperature profile of the boiler in order to avoid slagging. Straw co-firing lowers the ash viscosity leading to higher stickiness of the ash particles. Wood co-firing has only minor effects, due to the composition of wood ash and the low percentage of wood in the coal/biomass blend.

  13. Measuring reactive pools of Cd, Pb and Zn in coal fly ash from the UK using isotopic dilution assays

    International Nuclear Information System (INIS)

    Highlights: ? Isotope dilution is a useful method to resolve the reactivity of Cd and Pb in ash. ? Only 0.3–3% of the total Pb and Zn and 4–13% of the total Cd in coal ash are labile. ? Fly ash weathering exerts little impact on the lability of Cd, Pb and Zn. ? A 0.05 M EDTA extraction can be used as a simple proxy for isotope dilution assays. - Abstract: Large volumes of coal fly ash are continually being produced and stockpiled around the world and can be a source of environmentally sensitive trace elements. Whilst leaching tests are used for regulatory purposes, these provide little information about the true geochemical behaviour and ‘reactivity’ of trace elements in coal ash because they are poorly selective. Isotope dilution (ID) assays are frequently used in soil geochemistry as a means of measuring the reactive pools of trace metals that are in equilibrium with soil pore waters. This paper examines the applicability of multi-element ID assays in measuring the labile or reactive pool of Cd, Pb and Zn in a range of fresh and weathered fly ash, where pH is generally much more alkaline than in soils. The method generally worked well using 0.0005 M EDTA as a background electrolyte as it provided robust analytical ICP-MS measurements as well as fulfilling the important principle of ID that non-labile metal should not be solubilised. Reactive pools were equivalent to 0.5–3% of the total Pb pool and 4–13% of the total Cd pool. For Zn, where samples had pH < 11.5, the reactive Zn pool varied between 0.3% and 2%; when fresh ash samples with pH > 11.5 were tested, the method failed as the spiked isotope appeared to be sorbed or precipitated. Ash weathering was found to exert little impact on the lability of Cd, Pb and Zn. Isotope dilution results were compared with 0.43 M HNO3 and 0.05 M EDTA extractions, these commonly being used as analogues of the ID assay, and concluded that these can be used as fast, cost-effective and simple proxies for the ID assays. Results suggest that ID methods can be used to enhance knowledge of trace element behaviour in fresh and weathered fly ash

  14. Application of dry separative methods for decreasing content the residues unburned coal and separation Fe from black coal flies ash

    Directory of Open Access Journals (Sweden)

    František Ka?avský

    2008-06-01

    Full Text Available Main obstacle using of fly ashes in building, that is its main consumer, is the residue of unburned coal; it is expressed of loss onignition - LOI. In present, the valid STN and EU standard limits the content of LOI to 3 – 5 %, in national conditions maximum 7 %.Application of processing technologies also has to assure utilization of fly ash that provides a possibility of complex utilizationof individual products obtained by modification.By means of corona separation, based on different conductivity of individual fly ash elements, it is possible to separate unburnedcoal particles. The fly ash sample from black coal burning in melting boiler that was deposited on fly ash deposit, content of LOIof dielectric particle 6,45 % at 61 % weight yield was achieved. In the samples taken from dry taking of fly ash the non-conductingproduct contained 7,72 % of LOI at 73 % of weight yield.

  15. Uranium content of coal ashes from Southern Brazil coal fueled power stations, by the fission track registration technique

    International Nuclear Information System (INIS)

    The feasibility of the application of the fission track registration technique for the determination of uranium in coal ashes was shown. The wet method was employed using as detector the Makrofol KG=10 ?m, manufactured by Bayer. The coal ashes were originated from coal-fueled power stations localized in Southern Brazil. The results obtained ranged from 10 to 27 mg U/kg. Since the total error variation was from 18,4% to 23,8%, the method used was considered excellent. The determination of the uranium content in coal ashes is of considerable interest in environmental control in power stations, in their vicinity and wherever these ashes are used or stored. The technique used is the work proved to be very appropriate for the purpose aimed at. (Author)

  16. Trace and major element pollution originating from coal ash suspension and transport processes.

    Science.gov (United States)

    Popovic, A; Djordjevic, D; Polic, P

    2001-04-01

    Coal ash obtained by coal combustion in the "Nikola Tesla A" power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. Considering concentrations of seven trace elements as well as five major elements in extracts from a total of 12 samples, it can be concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport. PMID:11341293

  17. Assessing the potential of coal ash and bagasse ash as inorganic amendments during composting of municipal solid wastes.

    Science.gov (United States)

    Mohee, Romeela; Boojhawon, Anuksha; Sewhoo, Babita; Rungasamy, Selven; Somaroo, Geeta D; Mudhoo, Ackmez

    2015-08-15

    This study investigates the potential of incorporating inorganic amendments such as coal and bagasse ashes in different composting mixes. 10 different composting mixes were assessed as follows: A-20% bagasse ash (BA) with unsorted municipal solid wastes (UMSW); B-40% BA with UMSW; C-UMSW; D-20% BA with sorted municipal solid wastes (SMSW); E-40% BA with SMSW; F-SMSW; G-20% coal ash (CA) with UMSW; H-40% CA with UMSW; I-20% CA with SMSW and J-40% CA with SMSW. The composting processes were carried out in rotary drum composters. Composting mixes D, F, G and I achieved a temperature above 55 °C for at least 3 days, with the following peak temperatures: D-62 °C, F-57 °C, G-62 °C and I-58 °C. D resulted in the highest average net Volatile solids (VS) degradation of 68.6% and yielded the highest average volume reduction of 66.0%. The final compost from D, G, I, C and F were within range for electrical conductivities (EC) (794-1770 ?S/cm) and pH (6.69-7.12). The ashes also helped in maintaining high average water holding capacities within the range of 183-217%. The C/N ratio of sorted wastes was improved by the addition of 20% coal ash and bagasse ash. Higher germination indices, above 0.8 were obtained for the ash-amended compost (D, G, I), indicating the feasibility and enhancement of using bagasse and coal ash as inorganic amendment in the composting process. Regarding heavy metals content, the chromium concentration for the composting mix G was found to be the highest whereas mixes D and I showed compliance with the MS (Mauritian Standards) 164 standards. PMID:26093343

  18. Reduction of metal leaching in brown coal fly ash using geopolymers

    International Nuclear Information System (INIS)

    Current regulations classify fly ash as a prescribed waste and prohibit its disposal in regular landfill. Treatment of the fly ash can reduce the leach rate of metals, and allow it to be disposed in less prescribed landfill. A geopolymer matrix was investigated as a potential stabilisation method for brown coal fly ash. Precipitator fly ash was obtained from electrostatic precipitators and leached fly ash was collected from ash disposal ponds, and leaching tests were conducted on both types of geopolymer stabilised fly ashes. The ratio of fly ash to geopolymer was varied to determine the effects of different compositions on leaching rates. Fourteen metals and heavy metals were targeted during the leaching tests and the results indicate that a geopolymer is effective at reducing the leach rates of many metals from the fly ash, such as calcium, arsenic, selenium, strontium and barium. The major element leachate concentrations obtained from leached fly ash were in general lower than that of precipitator fly ash. Conversely, heavy metal leachate concentrations were lower in precipitator fly ash than leached pond fly ash. The maximum addition of fly ash to this geopolymer was found to be 60 wt% for fly ash obtained from the electrostatic precipitators and 70 wt% for fly ash obtained from ash disposal ponds. The formation of geopolymer in the presence of fly ash was studied using 29Si MAS-NMR and showed that a geopolymer matrix was formed. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) imaging showed the interaction of the fly ash with the geopolymer, which was related to the leachate data and also the maximum percentage fly ash addition

  19. Reduction of metal leaching in brown coal fly ash using geopolymers.

    Science.gov (United States)

    Bankowski, P; Zou, L; Hodges, R

    2004-10-18

    Current regulations classify fly ash as a prescribed waste and prohibit its disposal in regular landfill. Treatment of the fly ash can reduce the leach rate of metals, and allow it to be disposed in less prescribed landfill. A geopolymer matrix was investigated as a potential stabilisation method for brown coal fly ash. Precipitator fly ash was obtained from electrostatic precipitators and leached fly ash was collected from ash disposal ponds, and leaching tests were conducted on both types of geopolymer stabilised fly ashes. The ratio of fly ash to geopolymer was varied to determine the effects of different compositions on leaching rates. Fourteen metals and heavy metals were targeted during the leaching tests and the results indicate that a geopolymer is effective at reducing the leach rates of many metals from the fly ash, such as calcium, arsenic, selenium, strontium and barium. The major element leachate concentrations obtained from leached fly ash were in general lower than that of precipitator fly ash. Conversely, heavy metal leachate concentrations were lower in precipitator fly ash than leached pond fly ash. The maximum addition of fly ash to this geopolymer was found to be 60wt% for fly ash obtained from the electrostatic precipitators and 70wt% for fly ash obtained from ash disposal ponds. The formation of geopolymer in the presence of fly ash was studied using 29Si MAS-NMR and showed that a geopolymer matrix was formed. X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) imaging showed the interaction of the fly ash with the geopolymer, which was related to the leachate data and also the maximum percentage fly ash addition. PMID:15511575

  20. Hazards from radioactivity of fly ash of Greek coal power plants (CPP)

    International Nuclear Information System (INIS)

    Fly ash and fine dispersion releases from coal combustion in Greek coal power plants were studied. Concentrations in the fly ash up to 20 pCi/g and 10 pCi/g were measured for 238U and 226Ra respectively (not in secular equilibrium). Risk from the fly ash derives from its escape in particulate form or fine dispersion and from its use as a substitute for cement in concrete. The new data indicate that coal power plants discharge relatively larger quantities of radioactive material into the atmosphere than nuclear power plants of comparable size, during normal operation. (H.K.)

  1. Automated semiquantitative direct-current-arc spectrographic analysis of eight argonne premium coal ash samples

    Science.gov (United States)

    Skeen, C.J.; Libby, B.J.; Crandell, W.B.

    1990-01-01

    The automated semiquantitative direct-current-arc spectre-graphic method was used to analyze 62 elements in eight Argonne Premium Coal Ash samples. All eight coal ash samples were analyzed in triplicate to verify precision and accuracy of the method. The precision for most elements was within ??10%. The accuracy of this method is limited to +50% or -33% because of the nature of the standard curves for each of the elements. Adjustments to the computer program were implemented to account for unique matrix interferences in these particular coal ash samples.

  2. Preparation and characterization of carbon-enriched coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, B.; Izquierdo, M.T.; Mayoral, M.C.; Bona, M.T.; Martinez-Tarazona, R.M. [CSIC, Zaragoza (Spain)

    2008-09-15

    Carbon-enriched fractions have been obtained from two coal fly ash (FA) samples. The FA came from two pulverized-coal fired power stations (Lada and Escucha, Spain) and were collected from baghouse filters. Sieving was used to obtain carbon-enriched fractions, which were further subjected to two beneficiation processes: acid demineralization using HCl and HF, and oil agglomeration using soya oil-water. Yield in weight after sieving, unburned carbon content, and several physicochemical characteristics, of the obtained fractions were used to compare the performance of the beneficiation methods. Low carbon concentration was obtained by sieving. particularly in the case of Escucha FA. However, after acid demineralization or oil agglomeration, fractions containing unburned carbon in a range of 63% to 68% were obtained. These fractions showed differences in mineral phase composition and distribution depending on the FA and oil the beneficiation method used. The textural properties of the obtained fractions varied as a function of their carbon content and the beneficiation method used. However, no significant differences in morphology of the carbonaceous particles were found

  3. Trace and major element pollution originating from coal ash suspension and transport processes

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, A.; Djordjevic, D.; Polic, P. [University of Belgrade, Belgrade (Yugoslavia). Faculty of Science, Dept. of Chemistry

    2001-07-01

    Coal ash obtained from Nikola Tesla A power plant in Obrenovac, near Belgrade, Yugoslavia, is mixed with water of the Sava river and transported to the dump. In order to assess pollution caused by leaching of some minor and major elements during ash transport through the pipeline, two sets of samples (six samples each) were subjected to a modified sequential extraction. The first set consisted of coal ash samples taken immediately after combustion, while the second set was obtained by extraction with river water, imitating the processes that occur in the pipeline. Samples were extracted consecutively with distilled water and a 1 M solution of KCl, pH 7, and the differences in extractability were compared in order to predict potential pollution. It is concluded that lead and cadmium do not present an environmental threat during and immediately after ash transport to the dump. Portions of zinc, nickel and chromium are released during the ash transport, and arsenic and manganese are released continuously. Copper and iron do not present an environmental threat due to element leaching during and immediately after the coal ash suspension and transport. On the contrary, these elements, as well as chromium, become concentrated during coal ash transport. Adsorbed portions of calcium, magnesium and potassium are also leached during coal ash transport.

  4. Adsorption of anionic dyes from aqueous solutions onto coal fly ash and zeolite synthesized from coal fly ash

    International Nuclear Information System (INIS)

    Coal fly ash, a waste generated in coal-fired electric power plant, was used to synthesize zeolite by hydrothermal treatment with NaOH solution. The fly ash (CL-2) and this synthesized zeolite (ZM-2) that was characterized as hydroxy-sodalite were used as adsorbents for anionic dyes indigo carmine (IC), and reactive orange 16 (RO16) from aqueous solutions. Effects of contact time, initial dye concentration, pH, adsorbent mass, and temperature were evaluated in the adsorption processes. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism. The thermodynamics parameters demonstrated that the adsorption was spontaneous for all adsorption processes. The enthalpy data confirmed the endothermic nature for all adsorption processes except for IC/ZM-2 system which was exothermic. The entropy data showed an increased disorder at the solid/solution interface during the adsorption for all systems except for IC/ZM-2 whose negative entropy value indicated a decreased disorder at the interface. The adsorption isotherms were closely fitted to the Langmuir linear equation. The maximum adsorption capacities were 1.48 mg/g for the IC/CL-2 system; 1.13 mg/g for IC/ZM-2; 0.96 mg/g for RO16/CL-2, and 1.14 mg/g for RO16/ZM-2 at room temperature. The desorption study carried out with water, with acid aqueous solutions, and with an alkali aqueous solution showed to be inefficient both for recovering the dyes and regenerating the adsorbents. (author)

  5. Durable power performance of a direct ash-free coal fuel cell

    International Nuclear Information System (INIS)

    Highlights: •Investigation of a direct carbon fuel cell (DCFC) using raw and ash-free coal fuels. •Enhanced durability of a DCFC performance using ash-free coal. •Comprehensive characterization of physicochemical properties of coals. •Development of an optimal design of the configuration of DCFC reactor. -- Abstract: We have investigated the comparable performance of raw and ash-free coal in the operation of a direct carbon fuel cell (DCFC). The various structural and morphological analyses using SEM, TEM, EDX, XPS, XRD, and TGA are carried out to study the distinct physicochemical properties of coals. Due to contained volatile organic compounds, raw coal generates about a two-fold higher fuel cell performance compare to ash-free coal below a reaction temperature of 750 °C. However, over a cell temperature of 900 °C, both of them reach a similar power density of 170 mW cm?2. In the long-term operation of a DCFC, we observe a distinctly more durable power performance using ash-free coal than that of raw coal

  6. Relations between ash-fusion characteristics and depositional environment for an Appalachian Basin coal seam

    International Nuclear Information System (INIS)

    This paper reports that ash-fusion characteristics of the Lower Kittanning seam (western Pennsylvania) can be related to environment of deposition. Non-slagging coals (coals with ashes that have ash-fusion temperatures [AFTs] in excess of 2,600 degrees F) are associated with fresh-water environments that occur toward the margins of the basin. Slagging coals (coals with ashes that melt at temperatures less than 2,000 degrees F) occur in the central part of the basin, in areas overlain by shales that have been interpreted to have formed in a brackish environment. Trend-surface analysis indicates that whereas strong basinal trends do exist, locally variability can modify regional trends. High ash-fusion coals are associated with high clay (primarily kaolinite) contents, whereas low-fusion coals are associated with high pyrite and marcasite (and to a lesser extent, siderite) contents. Bivariate analysis of these data shows highly significant negative correlations between AFT and Fe2O3, pyrite, and siderite. Positive correlations exist between AFT and SiO2, Al2O3, TiO2, MgO, and K2O. Illite and kaolinite also correlate positively with AFT. An understanding of the oxide and mineral composition of the ash and the depositional environment of the peat can therefore be useful in the prediction of ash-fusion characteristics

  7. Mercury capture by selected Bulgarian fly ashes: Influence of coal rank and fly ash carbon pore structure on capture efficiency

    Science.gov (United States)

    Kostova, I.J.; Hower, J.C.; Mastalerz, Maria; Vassilev, S.V.

    2011-01-01

    Mercury capture by fly ash C was investigated at five lignite- and subbituminous-coal-burning Bulgarian power plants (Republika, Bobov Dol, Maritza East 2, Maritza East 3, and Sliven). Although the C content of the ashes is low, never exceeding 1.6%, the Hg capture on a unit C basis demonstrates that the low-rank-coal-derived fly ash carbons are more efficient in capturing Hg than fly ash carbons from bituminous-fired power plants. While some low-C and low-Hg fly ashes do not reveal any trends of Hg versus C, the 2nd and, in particular, the 3rd electrostatic precipitator (ESP) rows at the Republika power plant do have sufficient fly ash C range and experience flue gas sufficiently cool to capture measurable amounts of Hg. The Republika 3rd ESP row exhibits an increase in Hg with increasing C, as observed in other power plants, for example, in Kentucky power plants burning Appalachian-sourced bituminous coals. Mercury/C decreases with an increase in fly ash C, suggesting that some of the C is isolated from the flue gas stream and does not contribute to Hg capture. Mercury capture increases with an increase in Brunauer-Emmett-Teller (BET) surface area and micropore surface area. The differences in Hg capture between the Bulgarian plants burning low-rank coal and high volatile bituminous-fed Kentucky power plants suggests that the variations in C forms resulting from the combustion of the different ranks also influence the efficiency of Hg capture. ?? 2010 Elsevier Ltd.

  8. Combined adsorption and oxidation mechanisms of hydrogen sulfide on granulated coal ash.

    Science.gov (United States)

    Asaoka, Satoshi; Hayakawa, Shinjiro; Kim, Kyung-Hoi; Takeda, Kazuhiko; Katayama, Misaki; Yamamoto, Tamiji

    2012-07-01

    Hydrogen sulfide is highly toxic to benthic organisms and may cause blue tide with depletion of dissolved oxygen in water column due to its oxidation. The purpose of this study is to reveal the combined adsorption and oxidation mechanisms of hydrogen sulfide on granulated coal ash that is a byproduct from coal electric power stations to apply the material as an adsorbent for hydrogen sulfide in natural fields. Sulfur species were identified in both liquid and solid phases to discuss removal mechanisms of the hydrogen sulfide with the granulated coal ash. Batch experiments revealed that hydrogen sulfide decreased significantly by addition of the granulated coal ash and simultaneously the sulfate ion concentration increased. X-ray absorption fine structure analyses showed hydrogen sulfide was adsorbed onto the granulated coal ash and successively oxidized by manganese oxide (III) contained in the material. The oxidation reaction of hydrogen sulfide was coupling with reduction of manganese oxide. On the other hand, iron containing in the granulated coal ash was not involved in hydrogen sulfide oxidation, because the major species of iron in the granulated coal ash was ferrous iron that is not easily reduced by hydrogen sulfide. PMID:22487226

  9. Use of FBC ash and ponded coal-ash in ready-mixed concrete[ACI SP-235

    Energy Technology Data Exchange (ETDEWEB)

    Naik, T.R.; Kraus, R.N.; Chun, Y.M. [Univ. of Wisconsin, Milwaukee, WI (United States). Center for By-Products Utilization; Botha, F.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

    2006-07-01

    Clean coal ash waste from coal-fired power stations is currently under-utilized, as are control technologies for reducing SOx and NOx emissions resulting from fluidized bed combustion (FBC). FBC ash is produced by an FBC boiler in which the coal and limestone mixture is fluidized during the combustion process to allow removal of sulfur gases. This study was conducted to find practical solutions for using the waste product to address environmental concerns and the issue of reduced landfill space. In particular, the study focused on developing a manufacturing technology for the use of FBC and wet-collected, low-lime, coarse coal-ash (WA) in ready-mixed concrete. Nine concrete mixtures and test specimens were made at a ready-mixed concrete plant in Peoria, Illinois. The properties of fresh concrete were tested along with compressive strength, splitting-tensile strength, flexural strength and abrasion resistance for non-entrained, non-air-entrained with high-range water-reducing admixture (HRWRA), and air-entrained admixture (AEA) concrete. The percentage of FBC ash ranged from 22 to 45 per cent in the non-air-entrained concrete and 17 to 27 per cent in the concrete containing AEA. Resistance to salt-scaling of the AEA concrete mixtures exposed to deicing chemicals was also examined. The study showed that the use of normal dosages of AEA was not effective in concrete made with FBC ash. The results also indicated that non-air-entrained concrete mixtures could successfully incorporate up to 22 per cent FBC ash to cementitious material ratio (ash/cm) and a blend of 34 per cent FBC ash/cm and 5 per cent WA/aggregate. Up to 45 per cent FBC ash/cm and 5 per cent of WA/aggregate could also be used in non-air-entrained concrete mixtures using HRWRA for general concrete construction, as could concrete mixtures containing AEA incorporating up to 17 per cent FBC ash/cm with blends of 27 per cent FBC ash/cm and 5 per cent WA/aggregate. 17 refs., 2 tabs., 10 figs.

  10. Alkaline mine drainage from metal sulphide and coal mines: examples from Svalbard and Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Banks, D.; Parnachev, V.P.; Frengstad, B. (and others) [Holymoor Consultancy, Chesterfield (United Kingdom)

    2002-10-01

    This paper presents previously unpublished data from coal mines of the Abakan-Chernogorsk region, Khakassia, Serbia, the coal miens of Longycarbyen, Svalbard, an Arctic archipelago and magnetite mines in the Sayan and Kuznetsk-Alatau Mountains of Siberia to illustrate the chemistry of alkaline mine drainage waters and to discuss the possible mechanisms involved in their generation. 19 refs., 2 figs., 5 tabs.

  11. Activation analysis of pit-coal ash content with the use of isotopic fast neutron source

    International Nuclear Information System (INIS)

    The neutron activation techniques of coal ash determination are briefly reviewed and a new version of activation analysis using fast neutrons from 239Pu-Be source and basing on the reactions 28Si(n,p)28Al and 27Al(n,p)27Mg is proposed. 72 samples of pit-coals with ash content ranging from 3 to 40% were measured. The linear calibration function between ash content and both, 1.78 MeV and 0.84 MeV, ?-ray counts was obtained. The precision (0.94% ash for 17% ash content) and accuracy (1.4%ash for the whole range) were evaluated. Comparison of the results with those of fluorescent-scattering methods is made. (author)

  12. Secondary Industrial Minerals from Coal Fly Ash and Aluminium Anodising Waste Solutions:

    OpenAIRE

    Nugteren, H.W.

    2010-01-01

    Minerals that are extracted from the earth’s crust to be directly used for their properties are called industrial minerals. This research shows that such minerals can also be produced from industrial residues, hence the name secondary industrial minerals. In this thesis coal fly ash is chosen as one of the industrial residues to work with. Since reuse of coal fly ash is restricted by its technical and environmental quality, the first approach was to improve its quality and thereby extend ...

  13. Task 5.9 use of coal ash in recycled plastics and composite materials. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, D.J.; Dockter, B.A.; Eylands, K.E.; Pflughoeft-Hassett, D.F.

    1995-11-01

    The goal of this research project by the Energy & Environmental Research Center (EERC) was to determine the potential for coal ash to serve as a {open_quotes}functional filler{close_quotes} in plastics and other composite materials, with special emphasis on recycled plastics. The term functional filler is intended to indicate that the material added to the plastic does more than take up space and extend the use of the polymer. Determining the functional filler potential of ash was not the only intent of this project, since another prime objective was to find a use for materials currently considered waste. The term functional filler also opened a door to the use of cenospheres, which are currently marketed and for which there is sufficient market demand that they do not fit the category of a waste even though they are a product of coal combustion. Cenospheres, hollow spherical ash particles, were selected because of their unique properties. Although they currently have commercial applications, the unique nature of these materials make them an excellent candidate for use as a functional filler in composites. The ability to produce a commercially viable product from waste streams and a recycled material is a positive step toward reducing solid waste. The first task, since there are numerous types of coal ash, was to select suitable ash types for use in this project. Three basic types of material were selected: fly ash, a bottom ash, and a unique form of coal ash known as cenospheres.

  14. Task 5.9 - use of coal ash in recycled plastics and composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Hassett, D.J.; Dockter, B.A.; Eylands, K.E.; Pflughoeft-Hassett, D.F.

    1995-07-01

    The goal of this research project by the Energy & Environmental Research Center (EERC) was to determine the potential for coal ash to serve as a {open_quote}functional filler{close_quotes} in plastics and other composite materials, with special emphasis on recycled plastics. The term functional filler is intended to indicate that the material added to the plastic does more than take up space and extend the use of the polymer. Determining the functional filler potential of ash was not the only intent of this project, since another prime objective was to find a use for materials currently considered waste. The term functional filler also opened a door to the use of cenospheres, which are currently marketed and for which there is sufficient market demand that they do not fit the category of a waste even though they are a product of coal combustion. Cenospheres, hollow spherical ash particles, were selected because of their unique properties. Although they currently have commercial applications, the unique nature of these materials make them an excellent candidate for use as a functional filler in composites. The ability to produce a commercially viable product from waste streams and a recycled material is a positive step toward reducing solid waste. The first task, since there are numerous types of coal ash, was to select suitable ash types for use in this project. Three basic types of material were selected: fly ash, a bottom ash, and a unique form of coal ash known as cenospheres.

  15. Radiological impact of coal ash from the power plants in Hong Kong

    International Nuclear Information System (INIS)

    Samples of coal, furnace bottom ash and pulverised fly ash were collected from the two electric companies in Hong Kong. The samples were collected over a period of 1 year and therefore they were representative of the annual consumption of coal as well as the annual production of the ash. Special procedures were taken to separately burn the coal bought from different places so that the origins of the ash samples are traceable. The radionuclide contents, radon emanating fraction and porosity of the samples were measured. Mathematical models were then used to evaluate the radiological hazard of the ash samples when used in the building industry. Both the ? and radon exposures due to the coal ash loaded concrete in buildings are not much different from that due to unloaded concrete. External ? dose rate and 222Rn concentration at the centre of an uncovered ash lagoon are estimated to be 0.165 ?Gy h-1 and 2.9 Bq m-3, respectively, again not much different from the local background. On the other hand, the committed effective dose due to inhalation of PFA of about 7.1 x 108 B ?S?, where B is the PFA loading in air, can be an important source of exposure if resuspension of ash particles is not properly controlled. (author)

  16. Evaluation of the ecological risks to terrestrial wildlife associated with a coal ash disposal site

    International Nuclear Information System (INIS)

    Between 1955 and 1989, coal ash was deposited within an impounded watershed on the Oak Ridge Reservation, creating the 3.6 ha-Filled Coal Ash Pond (FCAP). The site has subsequently become vegetated, providing habitat for wildlife. To evaluate the risks that metals in the ash may pose to wildlife, ash, surface water, small mammal, and vegetation samples were collected and metal residues were determined. Metal concentrations, As and Se in particular, were elevated in ash, surface water, plant foliage, and small mammals relative to reference materials. Estimates of metal exposures received from food, water, and ash consumption were calculated for short-tailed shrews, white-footed mice, white-tailed deer, red fox, and red-tailed hawks. While shrews and mice were assumed to reside exclusively at and receive 100% exposure from the site, exposure experienced by deer, fox, and hawks was assumed to be proportional to the size of the site relative to their home range. Because deer had been observed to consume ash presumably for it's high sodium content, exposure experienced by deer consuming ash to meet sodium requirements was also estimated. To assess the risk of coal ash to wildlife, exposure estimates were compared to body-size adjusted toxicity data for each metal. These comparisons suggest that metals at the site may be detrimental to reproduction and survivorship of mice, shrews, deer and fox; hawks do not appear to be at risk

  17. Development of bricks with incorporation of coal ash and sludge from water treatment plant

    International Nuclear Information System (INIS)

    Sludge from treatment water Brazilian plant station are, frequently, disposed and launched directly in the water bodies, causing a negative impact in the environment. Also, coal ashes is produced by burning of coal in coal-fired power stations and is the industrial solid waste most generated in southern Brazil: approximately 4 million tons/y. The efficient disposal of coal ashes is an issue due to its massive volume and harmful risks to the environment. The aim of this work was study the feasibility of incorporating these two industrial wastes in a mass used in the manufacture of ecological bricks. Samples of fly ashes from a cyclone filter from a coal-fired power plant located at Figueira County in Parana State, Brazil and waterworks sludge of Terra Preta County in Sao Paulo State, Brazil, were used in the study. Fly ash-sludge and fly ash-sludge-soil-cement bricks were molded and tested, according to the Brazilians Standards. The materials were characterized by physical-chemical analysis, X-ray diffraction, thermal analysis, morphological analysis, Fourier transform infrared spectroscopy and granulometric analysis. The results indicate that the waterworks sludge and coal ashes have potential to be used on manufacturing soil-cement pressed bricks according to the of Brazilians Standards NBR 10836/94. (author)

  18. MULTISTAGE CAUSTIC LEACHING DE-ASHING OF NIGERIAN LAFIA-OBI COAL

    Directory of Open Access Journals (Sweden)

    M. M. Chagga

    2011-12-01

    Full Text Available Fractions of the high ash Nigerian Lafia-Obi coal L±250 ground to pass the 250 ?m sieve in threestages were subjected to proximate/ash composition analyses, hot aqueous leaching de-ashingwith water and sodium carbonate in multiple stages and in a H2O-Na2CO3-H2O sequence (withinitial solution homogenization. The results obtained showed that ash contents percent of 24.60,14.70 and 24.07 were obtained for fractions L-250(1, L-250(2 and L+250(2; respectively asagainst 32.55% in the as-received coal. The ash reductions obtained translate to overall averageash removal of about 38.66% at the 19.90% ash content of the concentrates blend at a good 1:20ratio of reagent to coal. The study also showed that a three stage leaching in the sequence H2ONa2CO3-H2O (HSH produced a higher leaching rate than Na2CO3-H2O-H2O (SHH. The ash contentof the concentrates blend at 19.90% is lower than 23.80% required for coal blends for Indianstandard coking practice, but higher than the maximum of 10% upper limit for the conventionalcokemaking practice. The reduction in ash content obtained at the atmospheric pressure treatmentof Lafia-Obi coal was found to compare favourably with that of a high pressure elevated temperatureautoclave leaching of an Illinois coal. Binary blend formulation between the prime coking westernCanada coal and Lafia-Obi coal as-leached showed that inclusion of 16.63% of the latter wasprobable and this translates to reduction in cost per ton of about $23.67. A successful upgrade ofthe leaching route derived to industrial scale will make Lafia-Obi coal available as a blend componentfor economical cokemaking.

  19. Study of enhanced fine coal de-sulphurization and de-ashing by ultrasonic flotation

    Energy Technology Data Exchange (ETDEWEB)

    Wen-ze Kang; Hai-xin Xun; Jun-tao Chen [Heilongjiang Institute of Science and Technology, Harbin (China). School of Resource and Environment

    2007-09-15

    The feasibility of using ultrasound to enhance the performance of de-sulphurization and de-ashing during slime flotation was investigated. The Setaram C80 calorimeter, the contact angle gauge DCAT21 and an electrophoresis apparatus were used to study the surface nature of coal, pyrite and refuse before and after ultrasonic conditioning. The yield, ash and sulfur contents of equally sized coal slimes were also measured before and after ultrasonic conditioning. The results show that ultrasonic conditioning can drive the separation of pyrite and refuse from coal. After ultrasonic conditioning the hydrophobicity of coal and hydrophilicity of pyrite and refuse increase. The perfect index of flotation, the perfect index of de-sulphurization and the percentage of de-sulphurization increase by 22.51%, 25.36% and 2.49%, respectively. This study shows that ultrasonic conditioning can enhance the performance of de-sulphurization and de-ashing of coal flotation methods. 14 refs., 2 figs., 6 tabs.

  20. Effects of Sediment Containing Coal Ash from the Kingston Ash Release on Embryo-Larval Development in the Fathead Minnow, Pimephales promelas (Rafinesque, 1820)

    Energy Technology Data Exchange (ETDEWEB)

    Greeley Jr, Mark Stephen [ORNL; Elmore, Logan R [ORNL; McCracken, Kitty [ORNL; Sherrard, Rick [Tennessee Valley Authority (TVA)

    2014-01-01

    The largest environmental release of coal ash in U.S. history occurred in December 2008 with the failure of a retention structure at the Tennessee Valley Authority (TVA) Kingston Fossil Plant in East Tennessee. A byproduct of coal-burning power plants, coal ash is enriched in metals and metalloids such as selenium and arsenic with known toxicity to fish including embryonic and larval stages. The effects of contact exposure to sediments containing up to 78 % coal ash from the Kingston spill on the early development of fish embryos and larvae were examined in 7-day laboratory tests with the fathead minnow (Pimephales promelas). No significant effects were observed on hatching success, incidences of gross developmental abnormalities, or embryo-larval survival. Results suggest that direct exposures to sediment containing residual coal ash from the Kingston ash release may not present significant risks to fish eggs and larvae in waterways affected by the spill.

  1. Rheology of fly ashes from coal and biomass co-combustion

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Frandsen, Flemming

    2010-01-01

    The presence of large amounts of alkali metals, chlorine and sulphur in most biomass fuels - compared to coal - can create serious ash-related problems such as deposition, agglomeration and/or corrosion. This paper discusses the viscosity characteristics of fly ash from the co-combustion of various coal/biomass blends in a pilot scale pf-boiler. The produced data provide information on the melting of the ash and its flow characteristics, as a function of temperature, which may be used to modify ...

  2. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn; Sander, Bo; Junker, Helle

    2009-01-01

    The properties of the ash from co-firing of coal and straw have a large influence on boiler operation, flue gas cleaning equipment and appropriate utilization of the fly ash. A study on the fuel composition and local conditions influence on fly ash properties has been done by making entrained flow reactor experiments with co-firing of coal and straw, making mineral and alkali vapor laboratory reactor experiments and by developing a model of KCl reaction with kaolin. The results include correlati...

  3. Pipeline design for hydraulic backfilling of coal mines with use of fly ash and fly ash-bottom ash mixture at high concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Parida, A.; Panda, D.; Senapati, P..; Mishra, R.N. [Regional Research Laboratory (CSIR), Bhubaneswar (India)

    2003-07-01

    Design of pipelines to handle fly ash and fly ash-bottom ash mixtures at high concentrations for backfilling purpose is investigated. Fly ash and bottom ash samples from the Captive Power Plant, NALCO, Angul, Orissa, were mixed with water to form a thick homogenous vehicle with non-Newtonian behaviour. The slurry is for transport from the surface to underground coal mines. The concentration of the ash slurry is in the range of 60-65% by weight and the fraction of bottom ash in the mixture varies from 0 to 40%. The rheological parameters of the slurry which indicate pseudoplastic power law behaviour are used to evaluate the head loss in pipelines having diameters varying from 100 to 300 mm. The results indicate that at a particular concentration, the slurry head loss decreases with increasing fraction of bottom ash in the mixture. Thus addition of bottom ash has a beneficial effect in reducing head requirement. For the backfilling system, full-flow conditions have been considered and the effects of pipe diameter, solids weight concentration and bottom ash fraction on the H/L ratio are determined. Since the high concentration ash slurry can be conveniently transported under laminar flow conditions, the calculations have been carried out at laminar flow velocities of 0.4 m/sec to 2.0 m/sec. From the computed results, the design plots have been formulated which indicate the solids backfilling rates as a function of H/L ratio for different pipe sizes and transport velocities at a given solids concentration. 10 refs., 9 figs., 1 tab.

  4. Radiological significance of coal, slag and fly ash samples from the Eastern Black Sea region

    International Nuclear Information System (INIS)

    This work presents a study of natural radioactivity levels in coal and its combustion residues (fly ash and slag) used in the houses in Black Sea Region, Turkey. Coal, fly ash and slag samples were provided from different locations of the region and analyzed by gamma spectroscopy using a high-purity germanium detector (HPGe). Also, chemical analyses of these samples were carried out using energy dispersive X-ray fluorescence spectrometer. The mean 226Ra activity concentrations in coal, slag and fly ash were measured as 83, 99 and 38 Bq kg-1, respectively. The mean 232Th activity concentrations in coal, slag and fly ash were measured as 108, 113 and 50 Bq kg-1, respectively. The mean 40K activity concentrations in coal, slag and fly ash were found to be 366, 381 and 204 Bq kg-1, respectively. The potential radiological hazards associated to these materials were evaluated by calculating the radium equivalent activity (Raeq), the air absorbed gamma dose rate (D), the annual effective dose rate (AED), the external hazard index (Hex) and internal hazard index (Hin) and compared with the internationally accepted or reference values. The mean Raeq values of the coal, fly ash and slag samples were lower than the recommended maximum values 370 Bq kg-1 by the Organization for Economic Cooperation and Development (OECD). The overall mean outdoor terrestrial gamma air absorbed dose rate in coal, fly ash and slag samples are 119, 129 and 62 nGy h-1 and the corresponding outdoor annual effective doses are 0.60, 0.32 and 0.64 mSv y-1, which is higher than the worldwide average (0.07 mSv y-1), respectively. Moreover, the enrichment factors relative to the input coal are calculated for the radionuclide contents observed. Calculated enrichment factor values for 226Ra and 232Th were found 1.14 and 1.01, respectively. (orig.)

  5. Mineral sequestration of CO2 by aqueous carbonation of coal combustion fly-ash

    International Nuclear Information System (INIS)

    The increasing CO2 concentration in the Earth's atmosphere, mainly caused by fossil fuel combustion, has led to concerns about global warming. A technology that could possibly contribute to reducing carbon dioxide emissions is the in-situ mineral sequestration (long term geological storage) or the ex-situ mineral sequestration (controlled industrial reactors) of CO2. In the present study, we propose to use coal combustion fly-ash, an industrial waste that contains about 4.1 wt.% of lime (CaO), to sequester carbon dioxide by aqueous carbonation. The carbonation reaction was carried out in two successive chemical reactions, first, the irreversible hydration of lime. CaO + H2O ? Ca(OH)2 second, the spontaneous carbonation of calcium hydroxide suspension. Ca(OH)2 + CO2 ? CaCO3 + H2O A significant CaO-CaCO3 chemical transformation (approximately 82% of carbonation efficiency) was estimated by pressure-mass balance after 2 h of reaction at 30 deg. C. In addition, the qualitative comparison of X-ray diffraction spectra for reactants and products revealed a complete CaO-CaCO3 conversion. The carbonation efficiency of CaO was independent on the initial pressure of CO2 (10, 20, 30 and 40 bar) and it was not significantly affected by reaction temperature (room temperature '20-25', 30 and 60 deg. C) and by fly-ash dose (50, 100, 150 g). The kinetic data demonstrated that the initial rate of CO2 transfer was enhanced by carbonation process for our experiments. The precipitate calcium carbonate was characterized by isolated micrometric particles and micrometric agglomerates of calcite (SEM observations). Finally, the geochemical modelling using PHREEQC software indicated that the final solutions (i.e. after reaction) are supersaturated with respect to calcium carbonate (0.7 ? saturation index ? 1.1). This experimental study demonstrates that 1 ton of fly-ash could sequester up to 26 kg of CO2, i.e. 38.18 ton of fly-ash per ton of CO2 sequestered. This confirms the possibility to use this alkaline residue for CO2 mitigation

  6. Genesis of some tertiary Indian coals from the chemical composition of ash – a statistical approach: Part 1

    Indian Academy of Sciences (India)

    Arpita Sharma; Ananya Saikia; Puja Khare; B P Baruah

    2014-10-01

    In the present investigation, 37 numbers of high sulphur tertiary coal samples from Meghalaya, India have been studied on the basis of proximate and ash analysis. Various statistical tools like Bivariant Analysis, Principal Component Analysis (PCA) and Hierarchical Clustering Analysis (HCA), and also the geochemical indicators were applied to determine the dominant detrital or authigenic affinity of the ash forming elements in these coals. The genetic interpretation of coal as well as the coal ash has been carried out based on chemical compositions of high temperature ash (HTA) by using Detrital/Authigenic Index. X-Ray Diffraction (XRD) analysis was also carried out to study the mineralogy of the studied coal ashes. Both statistical tools and geochemical indicators have confirmed the detrital nature of these coals as well as the ash forming elements.

  7. Characteristics of ash composition of primary coals for cokemaking in China

    Energy Technology Data Exchange (ETDEWEB)

    Shizhuang Shi; Xueying Zhou; Feng Shi; Gang Shi [Wuhan University of Science and Technology, Wuhan (China)

    2007-07-01

    The ash content and ash composition of primary coals for cokemaking in China, including ferric oxide (Fe{sub 2}O{sub 3}), calcium oxide (CaO), magnesium oxide (MgO), potassium oxide (K{sub 2}O), sodium oxide (Na{sub 2}O), manganese oxide (MnO), barium oxide (BaO), silicon oxide (SiO{sub 2}), aluminum oxide (Al{sub 2}O{sub 3}) and titanium oxide (TiO{sub 2}) , was analyzed systematically. The analytical result shows that the ash content (ad) of coal for cokemaking in China is about 10%. The ash of the coal consists of silicon oxide (SiO{sub 2}) and aluminum oxide (Al{sub 2}O{sub 3}). SiO{sub 2} + Al{sub 2}O{sub 3} accounts for about 80% of the ash and 7.5% of the dry coal. The alkali content (K{sub 2}O + Na{sub 2}O) accounts for about 1.1% and the biggest more than 2% of the ash; and 0.1% and biggest more than 0.2% of dry coal. 9 refs., 2 figs., 2 tabs.

  8. Advanced research and technology: Direct utilization recovery of minerals from coal fly ash. Fossil energy program

    Science.gov (United States)

    Burnet, G.; Murtha, M. J.; Adelman, D. J.

    1980-12-01

    Methods for utilizing coal fly ash through processes for the extraction of alumina and titania, and for the separation and use of an iron-rich fraction are described. Research of the HiChlor process for the extraction of alumina and titania by high temperature chlorination of a fly ash reductant mixture is described. An engineering cost evaluation is presented for a centralized HiChlor processing facility to process the fly ash of several large coal fueled power stations. Investigations for a high temperature lime soda process for extraction of alumina from fly ash included the use of several types of quarry limestones and waste materials to replace the limestone and/or soda ash.

  9. On Mattering: A Coal Ash Flood and the Limits of Environmental Knowledge

    Directory of Open Access Journals (Sweden)

    Hatmaker, Susie

    2014-05-01

    Full Text Available This paper investigates the largest flood of coal ash in United States history as an event at once monumental and insignificant. It traces affective forces generative of both the ash, and its invisibility. In the moment of rupture, the ash flowed out of a large holding pond in a spill of layered sediments – each layer of particulate a temporary resting place for a forceful trajectory of matter spurned into motion elsewhere in space and time. This paper takes up the atemporal matter of this coal ash flood to ask: out of what movements and connections was the ash formed? How did this particular landscape change to accommodate its accumulation? What trajectories flowed into the pond, and what hidden memories sat buried in its mass? Drawing on ethnographic and archival research, this paper weaves together juxtaposed scenes that form (some of the backstory of this event, and invites a reconsideration of the practices of knowledge that helped condition it.

  10. Impact of coal fly ash addition on ash transformation and deposition in a full-scale wood suspension-firing boiler

    DEFF Research Database (Denmark)

    Wu, Hao; Bashir, Muhammad Shafique; Jensen, Peter Arendt; Glarborg, Peter; Sander, Bo

    2013-01-01

    Ash transformation and deposition during pulverized wood combustion in a full-scale power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was characterized by using an advanced deposit probe system at two boiler locations with flue gas temperatures of about 1300 C and 800 C, respectively. The mechanisms of ash transformation and deposit formation were elaborated through a detailed characterization of the collected deposit...

  11. Testing the application of portable scintillation unit HOU 22 SCS in determining ash content in coal

    International Nuclear Information System (INIS)

    Operating tests were conducted for determining the ash content of coal on the conveyor belt using a portable scintillation radiometric unit of the HOU22 SCS type. The apparatus operated on the principle of scattered gamma radiation from a 75Se source with an activity of 18 MBq. The detection probe 41 mm in diameter was mounted at the inlet of the coal flow onto the conveyor belt. The accuracy of determination of the ash content of undersize coal used for power production (grain size 0 to 10 mm) was +-4.4%. (B.S.)

  12. Solid and fly ash materials ofbrown coal power plants, their characteristics and utilisation

    Directory of Open Access Journals (Sweden)

    Kovács Ferenc

    2002-09-01

    Full Text Available coal-fired power plants, a significant amount of residues is produced, depending on the technical parameters of coal separation and firing equipment. A large quantity of solid and fly ash and, in the case of flue gas desulphurisation, REA gypsum and wash-water is produced. The quantity of residues depends primarily on the ash and sulphur content of the fuel.Coal has a significant role in energy production and represents a considerable quantity in electric energy generation. At the turn of the millenary, about 4 billion tones of black coal and 800 million tones of brown coal and lignite are produced in the world annually. Depending on the ash content of the coals ? it varies between 5-8% and 30-35% ?, the quantity of solid and fly ash produced by firing is 1.0-1.5 billion tones per year. The quantity of residues of this kind accumulated in the past amounts to 100 billion tones.As far as the residues of coal-fired power plants are concerned, the annual fuel demand of the power plants of the Rhenish brown coal basin, where the average ash content of lignite is 7% and the average sulphur content is 0.2-0.8%, is 1 Mt referred to a power plant capacity of 100 MW. 60-70 kt solid + fly ash and, in the case of flue gas desulphurisation, 12-15 kt of gypsum is produced annually, referred to a capacity of 100 MW. In the East German areas, after the reconstruction of power plants, 30-50 kt of fly ash and, because of the higher sulphur content, 25-30 kt of gypsum and 4-5000 m3 of wash-water is produced annually, referred to a capacity of 100 MW.The composition of Hungarian lignite is significantly different to that of Rhenish brown coal. The ash content and combustible sulphur content of domestic lignite is considerably higher. The ash content of lignite varies between 15 and 25%, the average is 20%. In Visonta, 160-200 tones of solid + fly ash is produced annually, referred to a power plant capacity of 100 MW. With the flue gas desulphuriser installed recently, one can expect a gypsum quantity of 40-60 kt/year, referred to a capacity of 100 MW.

  13. Characterization of bottom ashes from coal pulverized power plants to determine their potential use feasibility

    International Nuclear Information System (INIS)

    The disposal of coal by products represents environmental and economical problems around the world. Therefore, the reuse and valorisation of this waste has become an important issue in the last decades. While high-value construction products containing fly ash were developed and its use is actually totally accepted as an addition to cement, the use of the bottom ash as supplementary cementitious material has not been allow. This paper examines the chemical and physical properties of fly ashes and bottom ashes from two different coal power plants in order to compare them and analyse the potential feasibility of bottom ash as cement replacement. The mechanical properties of cement mortars made with different percentages of both ashes were also study. The results obtained showed similar chemical composition of both kinds of ashes. The compressive strength values of mortars with 10 % and 25 % of cement replacement (at 28 days) were above the limits established in European standards and there were not significant differences between fly ash and bottom ash from both origins. (Author)

  14. Characterization of bottom ashes from coal pulverized power plants to determine their potential use feasibility

    Energy Technology Data Exchange (ETDEWEB)

    Menendez, E.; Alvaro, A. M.; Argiz, C.; Parra, J. L.; Moragues, A.

    2013-07-01

    The disposal of coal by products represents environmental and economical problems around the world. Therefore, the reuse and valorisation of this waste has become an important issue in the last decades. While high-value construction products containing fly ash were developed and its use is actually totally accepted as an addition to cement, the use of the bottom ash as supplementary cementitious material has not been allow. This paper examines the chemical and physical properties of fly ashes and bottom ashes from two different coal power plants in order to compare them and analyse the potential feasibility of bottom ash as cement replacement. The mechanical properties of cement mortars made with different percentages of both ashes were also study. The results obtained showed similar chemical composition of both kinds of ashes. The compressive strength values of mortars with 10 % and 25 % of cement replacement (at 28 days) were above the limits established in European standards and there were not significant differences between fly ash and bottom ash from both origins. (Author)

  15. The evaluation of geopolymer properties prepared by alkali activation of black coal ashes with high content of loss on ignition

    OpenAIRE

    Michalíková Františka; Krinická Ivana; Kolesárová Miroslava; Sisol Martin; Praš?áková Mária

    2010-01-01

    The utilization of fly ashes in Slovakia is lower than in other countries and dumping of fly ashes prevails. The dumping changeschemical and phase composition of fly ashes and so it decreases possibilities for their utilization. Fly ashes are mainly used in buildingindustry, where the content of loss on ignition (LOI) is limited due to standards. Black coal fly ashes produced in Slovakia have a highcontent of loss on ignition – more than 20 % - so they straight utilization in building industr...

  16. Application of percolation model to ash formation process in coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ryoichi Kurose; Hisao Makino; Hiromitsu Matsuda; Akira Suzuki [Central Research Institute of Electric Power Industry (CRIEPI), Kanagawa (Japan). Energy Engineering Research Laboratory

    2004-08-01

    The percolation model, which can account for swelling due to devolatilization and ash agglomeration, is applied to the ash formation process in coal combustion, and its validity is examined by comparison with the experimental results obtained using the drop tube furnace facility (DTF). The characteristics of a burning coal particle, such as particle diameter and specific surface area, are investigated in detail. Newlands and Plateau coals with different fuel ratios and ash contents are tested. The ambient temperature is set at 850 or 1400{sup o}C, at which temperature fluidized-bed or pulverized coal combustion occurs. The relationship between particle temperature and conversion of coal required in the percolation model is obtained by performing a numerical simulation of a combustion field in the DTF. The results show that the characteristics of the burning coal particle obtained through the computations of the percolation model are generally in agreement with the experimental data. The particle diameter of Newlands coal with a higher fuel ratio and ash content is larger than that of Plateau coal in the char-combustion-dominant process. For both Newlands and Plateau coals, compared to the particle diameter of the lower ambient temperature case of 850{sup o}C, that of the higher ambient temperature case of 1400{sup o}C becomes small in the early stage of the char-combustion-dominant process, but becomes large afterward. These behaviors can be explained in terms of swelling due to devolatilization and ash agglomeration. 23 refs., 12 figs., 1 tab., 1 append.

  17. Geochemistry of ultra-fine and nano-compounds in coal gasification ashes: A synoptic view

    Energy Technology Data Exchange (ETDEWEB)

    Kronbauer, Marcio A. [Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre, RS (Brazil); Izquierdo, Maria [School of Applied Sciences, Cranfield University, Bedfordshire MK43 0AL (United Kingdom); Dai, Shifeng [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Waanders, Frans B. [School of Chemical and Minerals Engineering, North West University (Potchefstroom campus), Potchefstroom 2531 (South Africa); Wagner, Nicola J. [School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg (South Africa); Mastalerz, Maria [Indiana Geological Survey, Indiana University, Bloomington, IN 47405-2208 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Oliveira, Marcos L.S. [Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Taffarel, Silvio R.; Bizani, Delmar [Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); and others

    2013-07-01

    The nano-mineralogy, petrology, and chemistry of coal gasification products have not been studied as extensively as the products of the more widely used pulverized-coal combustion. The solid residues from the gasification of a low- to medium-sulfur, inertinite-rich, volatile A bituminous coal, and a high sulfur, vitrinite-rich, volatile C bituminous coal were investigated. Multifaceted chemical characterization by XRD, Raman spectroscopy, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS provided an in-depth understanding of coal gasification ash-forming processes. The petrology of the residues generally reflected the rank and maceral composition of the feed coals, with the higher rank, high-inertinite coal having anisotropic carbons and inertinite in the residue, and the lower rank coal-derived residue containing isotropic carbons. The feed coal chemistry determines the mineralogy of the non-glass, non-carbon portions of the residues, with the proportions of CaCO{sub 3} versus Al{sub 2}O{sub 3} determining the tendency towards the neoformation of anorthite versus mullite, respectively. Electron beam studies showed the presence of a number of potentially hazardous elements in nanoparticles. Some of the neoformed ultra-fine/nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of sulfides and sulfates. - Highlights: • Coal waste geochemisty can provide increased environmental information in coal-mining areas. • Oxidation is the major process for mineral transformation in coal ashes. • The electron bean methodology has been applied to investigate neoformed minerals.

  18. Geochemistry of ultra-fine and nano-compounds in coal gasification ashes: A synoptic view

    International Nuclear Information System (INIS)

    The nano-mineralogy, petrology, and chemistry of coal gasification products have not been studied as extensively as the products of the more widely used pulverized-coal combustion. The solid residues from the gasification of a low- to medium-sulfur, inertinite-rich, volatile A bituminous coal, and a high sulfur, vitrinite-rich, volatile C bituminous coal were investigated. Multifaceted chemical characterization by XRD, Raman spectroscopy, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS provided an in-depth understanding of coal gasification ash-forming processes. The petrology of the residues generally reflected the rank and maceral composition of the feed coals, with the higher rank, high-inertinite coal having anisotropic carbons and inertinite in the residue, and the lower rank coal-derived residue containing isotropic carbons. The feed coal chemistry determines the mineralogy of the non-glass, non-carbon portions of the residues, with the proportions of CaCO3 versus Al2O3 determining the tendency towards the neoformation of anorthite versus mullite, respectively. Electron beam studies showed the presence of a number of potentially hazardous elements in nanoparticles. Some of the neoformed ultra-fine/nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of sulfides and sulfates. - Highlights: • Coal waste geochemisty can provide increased environmental information in coal-mining areas. • Oxidation is the major process for mineral transformation in coal ashes. • The electron bean methodology has been applied to investigate neoformed minerals

  19. Effect of Total Ash Content and Coals Ash Composition on Coke Reactivity

    OpenAIRE

    Gulyaev, Vitaly; Barsky, Vadim; Gurevina, Natalya

    2009-01-01

    ????????????? ???????? ??? ????? ??????????? ????????? ??????? ?? ????????? ????????? ?????. ????????, ?? ??????? ??? ???????? ?? ???? ????????? ???????? ? ?????????? ??????? ?? ?? ????????? ???????? ??? ????????? ????????? ???????, ?? ??????????. ???????? ???? ??? ??????????? ??? ??????????? ??????????? ??????? ??????? ?? ??????? ???? ?????????? ???? ?, ?? ????????, ?? ????????? ????????? ?????.The article deals with the hypothesis of the influence of coals mineral co...

  20. RECLAMATION OF ALKALINE ASH PILES AND PROTECTION OF THEIR ENVIRONMENT AGAINST DUSTING

    Science.gov (United States)

    The objective of this study was to develop methods to reclaim and stabilize by vegetation fly ash and bottom ash from bituminous and lignite fired power plants. The ash had been transported from the power plant as a slurry and disposed of in ponds. Ashes from these power plants w...

  1. Full-scale ash deposition measurements at Avedøre Power Plant unit 2 during suspension-firing of wood with and without coal ash addition.

    DEFF Research Database (Denmark)

    Wu, Hao; Shafique Bashir, Muhammad

    2012-01-01

    The formation of deposits during suspension-firing of wood at Avedøre Power Plant unit 2 (AVV2) was studied by using an advanced deposit probe system. The tests were conducted both with and without coal ash addition, and at two different locations with flue gas temperatures of 1250-1300 oC and 750-800 oC respectively. The deposit formation process was studied quantitatively though the mass uptake data from the load-cell of the probe, while camera pictures were used to qualitatively verify the obtained mass uptake data and to explain the deposit buildup/shedding mechanisms. The collected deposits along with the fly ash and bottom ash from the plant were characterized extensively by SEM-EDS, ICP-OES/IC and XRD. Based on the results from the present work, the deposit formation and shedding mechanisms under different operational conditions were proposed and discussed. The influence of coal ash addition on deposit formation during wood suspension-firing at AVV2 was evaluated. It was revealed that the addition of coal fly ash could significantly influence the ash deposition/shedding behaviors and the deposit properties. The effect was evident at both measurement locations. At the location with a high flue gas temperature of 1250-1300 oC, although the addition of coal fly ash increased the differential deposit formation rate (DDF-rate) and the ash deposition propensity, the deposit removal frequency were considerably increased and the major shedding mechanism was changed from soot-blowing induced shedding to natural shedding. This implied that the deposits at high temperatures were more easily removable when coal ash was added. Besides, the amount of K2SO4 in the high-temperature deposits was considerably reduced when coal ash was added, which was probably favorable in order to minimize corrosion. At the location with a low flue gas temperature of 750-800 oC, the addition of coal fly ash reduced the ash deposition propensity and caused the formed deposits being easily removable. Moreover, the KCl and KOH/K2CO3 found in the low-temperature deposits without coal ash addition disappeared when coal ash was added, which was also favorable from a corrosion point of view.

  2. Effect of mixes made of coal bottom ash and fly ash on the mechanical strength and porosity of Portland cement

    Directory of Open Access Journals (Sweden)

    Argiz, C.

    2013-03-01

    Full Text Available New additions to the cement are needed to achieve a more sustainable and durable construction material. Within this context, bottom ashes can be used as a main constituent of Portland cements when it is mixed in an optimized proportion with fly ashes. The mechanical characteristics of standarized mortars made of mixes of pulverized coal combustion bottom and fly ashes are studied. The mortars were made of ordinary Portland cement (CEM I 42.5 N and mixes of bottom ashes with fly ashes in similar proportions to those of CEM II/A-V, CEM II/B-V and CEM IV/A (V. Summing up, it can be said that the utilization of bottom ashes mixed with fly ashes in replacement levels from 0% to 100% do not affect significantively on the mechanical caracteristics of the mortars considered in the present study which had an addition maximum content of 35%.

    La utilización de nuevas adiciones en el cemento es necesaria con el fin de obtener un material más sostenible y durable. En este sentido, las cenizas de fondo o cenicero de las centrales termoeléctricas de carbón se podrían reciclar siendo empleadas como un componente principal de los cementos Portland. Se han estudiado las propiedades mecánicas de unos morteros normalizados elaborados con mezclas de cenizas volantes con cenizas de fondo fabricados con unos porcentajes similares a los correspondientes de los CEM II/A-V, CEM II/B-V y CEM IV/A (V. En conclusión, la utilización de mezclas de cenizas de fondo o cenicero con cenizas volantes sustituyendo a éstas últimas entre el 0% y el 100%, no influye significativamente en el comportamiento mecánico de los morteros estudiados en los que el contenido máximo de adición ha sido del 35%, si bien afecta a determinados aspectos microestructurales, como la cantidad y distribución de poros capilares.

  3. Trophic structure and metal bioaccumulation differences in multiple fish species exposed to coal ash-associated metals

    Energy Technology Data Exchange (ETDEWEB)

    Otter, Ryan [Middle Tennessee State University; Bailey, Frank [Middle Tennessee State University; Fortner, Allison M [ORNL; Adams, Marshall [ORNL

    2012-01-01

    On December 22, 2008 a dike containing coal fly ash from the Tennessee Valley Authority Kingston Fossil Plant near Kingston Tennessee USA failed and resulted in the largest coal ash spill in U.S. history. Coal ash, the by-product of coal combustion, is known to contain multiple contaminants of concern, including arsenic and selenium. The purpose of this study was to investigate the bioaccumulation of arsenic and selenium and to identify possible differences in trophic dynamics in feral fish at various sites in the vicinity of the Kingston coal ash spill. Elevated levels of arsenic and selenium were observed in various tissues of largemouth bass, white crappie, bluegill and redear sunfish from sites associated with the Kingston coal ash spill. Highest concentrations of selenium were found in redear sunfish with liver concentrations as high as 24.83 mg/kg dry weight and ovary concentrations up to 10.40 mg/kg dry weight at coal ash-associated sites. To help explain the elevated selenium levels observed in redear sunfish, investigations into the gut pH and trophic dynamics of redear sunfish and bluegill were conducted which demonstrated a large difference in the gut physiology between these two species. Redear sunfish stomach and intestinal pH was found to be 1.1 and 0.16 pH units higher than in bluegill, respectively. In addition, fish from coal ash-associated sites showed enrichment of 15N & 13C compared to no ash sites, indicating differences in food web dynamics between sites. These results imply the incorporation of coal ash-associated compounds into local food webs and/or a shift in diet at ash sites compared to the no ash reference sites. Based on these results, further investigation into a broader food web at ash-associated sites is warranted.

  4. Nano-mineralogical investigation of coal and fly ashes from coal-based captive power plant (India): An introduction of occupational health hazards

    International Nuclear Information System (INIS)

    Coal derived nano-particles has been received much concern recently around the world for their adverse effects on human health and the environment during their utilization. In this investigation the mineral matter present in some industrially important Indian coals and their ash samples are addressed. Coal and fly ash samples from the coal-based captive power plant in Meghalaya (India) were collected for different characterization and nano-mineralogy studies. An integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS analysis, and Mössbauer spectroscopy were used to know their extent of risks to the human health when present in coal and fly ash. The study has revealed that the coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals in lesser quantities were found to be present in the coal fly ash. Fly ash carbons were present as chars. Indian coal fly ash also found to contain nanominerals and ultrafine particles. The coal-fired power plants are observed to be the largest anthropogenic source of Hg emitted to the atmosphere and expected to increase its production in near future years. The Multi Walled Carbon Nano-Tubes (MWCNTs) are detected in our fly ashes, which contains residual carbonaceous matter responsible for the Hg capture/encapsulation. This detailed investigation on the inter-relationship between the minerals present in the samples and their ash components will also be useful for fulfilling the clean coal technology principles. - Highlights: • We research changes in the level of ultrafine and nanoparticles about coal–ash quality. • Increasing dates will increase human health quality in this Indian coal area. • Welfare effects depend on ex-ante or ex-post assumptions about quality information

  5. Nano-mineralogical investigation of coal and fly ashes from coal-based captive power plant (India): An introduction of occupational health hazards

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcos L.S. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Development Department of Touristic Opportunities, Catarinense Institute of Environmental Research and Human Development – IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Marostega, Fabiane; Taffarel, Silvio R. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Saikia, Binoy K. [Coal Chemistry Division, CSIR-North East Institute of Science and Technology, Jorhat 785006 (India); Waanders, Frans B. [School of Chemical and Minerals Engineering, North West University (Potchefstroom campus), Potchefstroom 2531 (South Africa); DaBoit, Kátia [Environmental Science and Nanotechnology Department, Institute of Environmental Research and Human Development – IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Baruah, Bimala P. [Coal Chemistry Division, CSIR-North East Institute of Science and Technology, Jorhat 785006 (India); and others

    2014-01-01

    Coal derived nano-particles has been received much concern recently around the world for their adverse effects on human health and the environment during their utilization. In this investigation the mineral matter present in some industrially important Indian coals and their ash samples are addressed. Coal and fly ash samples from the coal-based captive power plant in Meghalaya (India) were collected for different characterization and nano-mineralogy studies. An integrated application of advanced characterization techniques such as X-ray diffraction (XRD), High Resolution-Transmission Electron microscopy (HR-TEM)/(Energy Dispersive Spectroscopy) EDS/(selected-area diffraction pattern) SAED, Field Emission-Scanning Electron Microscopy (FE-SEM)/EDS analysis, and Mössbauer spectroscopy were used to know their extent of risks to the human health when present in coal and fly ash. The study has revealed that the coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals in lesser quantities were found to be present in the coal fly ash. Fly ash carbons were present as chars. Indian coal fly ash also found to contain nanominerals and ultrafine particles. The coal-fired power plants are observed to be the largest anthropogenic source of Hg emitted to the atmosphere and expected to increase its production in near future years. The Multi Walled Carbon Nano-Tubes (MWCNTs) are detected in our fly ashes, which contains residual carbonaceous matter responsible for the Hg capture/encapsulation. This detailed investigation on the inter-relationship between the minerals present in the samples and their ash components will also be useful for fulfilling the clean coal technology principles. - Highlights: • We research changes in the level of ultrafine and nanoparticles about coal–ash quality. • Increasing dates will increase human health quality in this Indian coal area. • Welfare effects depend on ex-ante or ex-post assumptions about quality information.

  6. Ecological risk assessment for residual coal fly ash at Watts Bar Reservoir, Tennessee.

    Science.gov (United States)

    Carriker, Neil E; Jones, Daniel S; Walls, Suzanne J; Stojak, Amber R

    2015-01-01

    The Tennessee Valley Authority conducted a Baseline Ecological Risk Assessment (BERA) for the Kingston Fossil Plant ash release site to evaluate potential effects of residual coal ash on biota in Watts Bar Reservoir, Tennessee. The BERA was in response to a release of 4.1 million m(3) of coal ash on December 22, 2008. It used multiple lines of evidence to assess risks for 17 different ecological receptors to approximately 400000?m(3) of residual ash in the Emory and Clinch rivers. Here, we provide a brief overview of the BERA results and then focus on how the results were used to help shape risk management decisions. Those decisions included selecting monitored natural recovery for remediation of the residual ash in the Emory and Clinch rivers and designing a long-term monitoring plan that includes adaptive management principles for timely adjustment to changing conditions. This study demonstrates the importance of site-specific ecological data (e.g., tissue concentrations for food items, reproductive data, and population data) in complex ecological risk assessments. It also illustrates the value of the US Environmental Protection Agency's (USEPA) data quality objectives process in building consensus and identifying multiple uses of results. The relatively limited adverse effects of this likely worst-case scenario for ash-related exposures in a lotic environment provide important context for the USEPA's new coal combustion residue disposal rules. PMID:25346032

  7. Laser Induced Breakdown Spectroscopy application for ash characterisation for a coal fired power plant

    International Nuclear Information System (INIS)

    The aim of this work was to apply the LIBS technique for the analysis of fly ash and bottom ash resulting from the coal combustion in a coal fired power plant. The steps of presented LIBS analysis were pelletizing of powdered samples, firing with laser and spectroscopic detection. The analysis 'on tape' was presented as an alternative fast sampling approach. This procedure was compared with the usual steps of normalized chemical analysis methods for coal which are coal calcination, fluxing in high temperature plasma, dilution in strong acids and analyzing by means of ICP-OES and/or AAS. First, the single pulse LIBS approach was used for determination and quantification of elemental content in fly ash and bottom ash on the exit of the boiler. For pellet preparation, ash has to be mixed with proper binder to assure the sample resistance. Preparation of the samples (binder selection and pressing/pelletizing conditions) was determined and LIBS experimental conditions optimized. No preparation is necessary in 'on tape' sampling. Moreover, double-pulse approach in orthogonal reheating configuration was applied to enhance the repeatability and precision of the LIBS results and to surpass the matrix effect influencing the calibration curves in case of some elements. Obtained results showed that LIBS responses are comparable to the normalized analytical methods. Once optimized the experimental conditions and features, application of LIBS may be a promising technique for combustion process control even in on-line mode.

  8. Thermal properties of insulating material prepared from coal fly ash and asphalt

    International Nuclear Information System (INIS)

    Coal power plants are producing ash in enormous quantity as fly ash and bottom ash, whenever coal is combusted. Lakhra Coal Power Plant produces waste of solid fossil fuel and lime stone. Due to the silica, alumina and iron oxide it is good to be used in cement preparation and land filling. In this study a new application is identified, which is more useful and beneficial. This paper presents the results carried out investigating the insulating material prepared from the coal fly ash and asphalt by using the simple unit operations of sizing the materials. At melting temperature of the asphalt sieved fly ash is mixed with it to produce complex heavy sludge. Two samples of different ratios from the rapidly solidifying insulating material were prepared in the molding press at 200 psi pressure. Arm-field heat conduction apparatus HT-l was applied to test its thermal properties. Thermal properties of the material were observed to be heat resistant with mean thermal conductivity at 10 watt 0.8949 w/m-K for Sample No.1 and 0.91886 w/m-K for Sample No.2; whereas the mean thermal resistances calculated were 30.4 I 65m/sup 2/-K/w and 29.6234m/sup 2/-K/w, respectively. The results obtained during this study are satisfactory and we hope that the insulation material prepared would be used in Pakistan in building constructions for heat resistance and insulation purposes. (author)

  9. MULTISTAGE CAUSTIC LEACHING DE-ASHING OF NIGERIAN LAFIA-OBI COAL

    OpenAIRE

    M. M. Chagga; A. A. Afonja; S. A. IBITOYE; Adeleke, A. A.

    2011-01-01

    Fractions of the high ash Nigerian Lafia-Obi coal L±250 ground to pass the 250 ?m sieve in threestages were subjected to proximate/ash composition analyses, hot aqueous leaching de-ashingwith water and sodium carbonate in multiple stages and in a H2O-Na2CO3-H2O sequence (withinitial solution homogenization). The results obtained showed that ash contents percent of 24.60,14.70 and 24.07 were obtained for fractions L-250(1), L-250(2) and L+250(2); respectively asagainst 32.55% in the as-receive...

  10. Radiometric determination of ash content of coal with variable chemical composition

    International Nuclear Information System (INIS)

    The first part of the paper contains a review of the well knows radiometric methods of determining the ash content of coal, as well as the techniques for overcoming interferences due to variations of iron content. The advantages of the intrinsic compensation method with the use of 238Pu source, are shown. The experimental results concerning the other sources of errors, in particular grain size and water content effects, are presented. Precision, accuracy and possibilities of applying suggested method for rapid control of the ash content of coal in industry, are discussed. (author)

  11. Nuclear techniques for analysis of coal for calorific value, ash and moisture

    International Nuclear Information System (INIS)

    This bibliography includes references on nuclear techniques for analysis of coal for calorific value, ash and moisture content. As the search was directed particularly towards measurement of the ash content of coal using x- and gamma-ray methods, references covering only ?-ray techniques have been placed in a separate section. References from Chemical Abstracts prior vol.62 (1965) do not cite the language of the original article. The language of the original has been given for all other articles not in English. (author)

  12. [Leaching of Rare Earth Elements from Coal Ashes Using Acidophilic Chemolithotrophic Microbial Communities].

    Science.gov (United States)

    Muravyov, M I; Bulaev, A G; Melamud, V S; Kondrat'eva, T F

    2015-01-01

    A method for leaching rare earth elements from coal ash in the presence of elemental sulfur using communities of acidophilic chemolithotrophic microorganisms was proposed. The optimal parameters determined for rare element leaching in reactors were as follows: temperature, 45 degrees C; initial pH, 2.0; pulp density, 10%; and the coal ash to elemental sulfur ratio, 10 : 1. After ten days of leaching, 52.0, 52.6, and 59.5% of scandium, yttrium, and lanthanum, respectively, were recovered. PMID:26263628

  13. Elemental composition of coal fly ash: Malta coal power station in the Mpumalanga province in South Africa case study using nuclear and related analytical techniques

    International Nuclear Information System (INIS)

    Epithermal neutron activation analysis along with ICP-OES, LA ICP-MS, and XRF were used to determine the elemental composition of coal fly ash from the Malta coal power station in the Mpumalanga province of South Africa. A total of 54 major, trace and rare-earth elements were obtained by the four analytical techniques. The results were compared and the discrepancies discussed to show the merits and drawbacks of each of the techniques. It was shown that the elemental content of this particular coal fly ash is of the same order as the NIST standard reference material Coal Fly Ash 1633b

  14. Analysis of natural radionuclides in coal, slag and ash in coal-fired power plants in Serbia

    Directory of Open Access Journals (Sweden)

    Jankovi? M.M.

    2011-01-01

    Full Text Available The radioactivity monitoring in the “Nikola Tesla”, “Kolubara”, “Morava” and “Kostolac” coal-fired power plants was performed by the Radiation and Environmental Protection Laboratory, Vin?a Institute of nuclear sciences in the period 2003-2010. Monitoring included the analysis of soil, water, flying ash, slag, coal and plants. This paper presents the results of the radioactivity analysis of coal, ash and slag samples. Naturally occurring radionuclides 226Ra, 232Th, 40K, 235U, 238U, and 210Pb as well as the man-made radionuclide 137Cs were determined by gamma spectrometry using HPGe detector. The concentrations of pairs of radionuclides were statistically tested to determine the correlation between them. Based on the obtained results, health effect due to the activity of these radionuclides was estimated via radium equivalent (Raeq, external hazard index (Hex, external gamma absorbed dose rate ( and annual effective dose.

  15. Conceptual flow sheets development for coal conversion plant coal handling-preparation and ash/slag removal operations

    Energy Technology Data Exchange (ETDEWEB)

    1979-07-01

    This report presents 14 conceptual flow sheets and major equipment lists for coal handling and preparation operations that could be required for future, commercial coal conversion plants. These flow sheets are based on converting 50,000 tons per day of clean coal representative of the Pittsburgh and Kentucky No. 9 coal seams. Flow sheets were used by Union Carbide Corporation, Oak Ridge National Laboratory, in a survey of coal handling/preparation equipment requirements for future coal conversion plants. Operations covered in this report include run-of-mine coal breaking, coarse coal cleaning, fine coal cleaning, live storage and blending, fine crushing (crushing to top sizes ranging from 1/4-inch to 20 mesh), drying, and grinding (70 percent minus 200 mesh). Two conceptual flow sheets and major equipment lists are also presented for handling ash or granulated slag and other solid wastes produced by nine leading coal conversion processes. These flow sheets provide for solid wastes transport to an environmentally acceptable disposal site as either dry solids or as a water slurry.

  16. Estabilização de solo contaminado com zinco usando zeólitas sintetizadas a partir de cinzas de carvão Stabilization of zinc-contamined soil using zeolites synthesized from coal ashes

    Directory of Open Access Journals (Sweden)

    Denise Alves Fungaro

    2004-08-01

    Full Text Available The effect of synthetic zeolites on stabilizing Zn-contaminated soil using 0.01 mol L-1 CaCl2 leaching solution in batch experiments was investigated. The zeolites were synthesized from coal ash by hydrothermal treatment with alkaline solution. The additive enhanced the sorption capacity of the soil and reduced leaching. Zinc leaching was reduced by more than 80% using a minimum of 10% additive. The higher cation exchange capacity of the zeolite/soil mixtures and higher pH were responsible for stabilizing Zn in soil. The poly(2-aminobenzenesulfonic acid-coated mercury thin-film electrode was used for the determination of zinc.

  17. Impact of coal fly ash addition on ash transformation and deposition in a full-scale wood suspension-firing boiler

    DEFF Research Database (Denmark)

    Wu, Hao; Bashir, Muhammad Shafique

    2013-01-01

    Ash transformation and deposition during pulverized wood combustion in a full-scale power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was characterized by using an advanced deposit probe system at two boiler locations with flue gas temperatures of about 1300 C and 800 C, respectively. The mechanisms of ash transformation and deposit formation were elaborated through a detailed characterization of the collected deposits and fly ashes. The results implied that during pulverized wood combustion, the formation of deposits at the location with high flue gas temperatures was characterized by a slow and continuous growth of deposits followed by the shedding of a large layer of deposits, while at the location with low flue gas temperature the deposit formation started with a slow build-up and the amount of deposits became almost constant after a few hours. The formed deposits, especially those at the location with low flue gas temperatures, contained a considerable amount of K2SO4, KCl, and KOH/K2CO3. With the addition of a large amount (about 4 times of the mass flow of wood ash) of coal fly ash to the boiler, these alkali species were effectively removed both in the fly ash and in the deposits. Although the ash deposition rate at the location with high flue gas temperature was increased with coal fly ash addition, the removability of the deposits was significantly improved, resulting in a more frequent shedding of the deposits. Overall, the results from this work suggest that coal fly ash can be an effective additive to minimize the possible ash deposition and corrosion problems during suspension-firing of wood. © 2013 Elsevier Ltd. All rights reserved.

  18. Suspension-firing of wood with coal ash addition: Probe measurements of ash deposit build-up at Avedøre Power Plant (AVV2)

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt

    2012-01-01

    This report is about full-scale probe measurements of deposit build-up and removal conducted at the Avedøreværket Unit 2, a 800 MWth suspension boiler, firing wood and natural gas with the addition of coal ash. Coal ash was used as an additive to capture potassium (K) from wood-firing. Investigations of deposit formation rate were made by use of an advanced online ash deposition/shedding probe. Quantification of ash deposition and shedding was made via deposit mass uptake signals obtained from the deposit probe. The influence of coal ash, flue gas temperature, probe surface temperature and boiler load on ash deposition propensity was investigated. Results of ash deposition propensity showed increasing trend with increasing flue gas temperature. Video monitoring revealed that the deposits formed were not sticky and could be easily removed, and even at very high flue gas temperatures (> 1350 oC), deposit removal through surface melting was not identified. SEM-EDS analysis of the deposits showed significant presence of Ca, Al and Si, indicating that a significant amount of K has been captured by coal ash to form deposits rich in calcium-aluminum-silicates, and possible release of Cl to the gas phase as HCl(g). Effect of boiler operational parameters on gas emissions has also been investigated.

  19. Ash transformation in suspension fired boilers co-firing coal and straw

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt; Jensen, Anker Degn

    2009-01-01

    To study the influence of local conditions on the reaction between gaseous KCl and kaolin or coal fly ash experiments were done on CHECs electrically heated entrained flow reactor, which can simulate the local conditions in suspension fired boilers. The experimental results were compared with model calculations to support the interpretation. The extent of the reaction between KCl vapor and coal minerals was evaluated by the amount of formed water insoluble potassium in the product. The effects o...

  20. Evaluation of interactions between soil and coal fly ash leachates using column percolation tests.

    Science.gov (United States)

    Tsiridis, V; Petala, M; Samaras, P; Sakellaropoulos, G P

    2015-09-01

    The aim of this work was the assessment of the environmental impact of different origin fly ashes with regard to their final disposal. The experimental procedure included the performance of single column tests and column tests of fly ash and soil in series. The appraisal of the potential environmental hazards was implemented using physicochemical analyses and bioassays. Two different fly ash samples were examined, one fly ash produced from the combustion of sub-bituminous coal (CFA) and one fly ash produced from the combustion of lignite (LFA). Single column percolation tests were performed according to NEN 7343 protocol, while fly ash/soil experiments were conducted incorporating slight modifications to this protocol. The study focused on the release of metals Ba, Cr, Cu, Mo, Se and Zn and the ecotoxic behavior of leachates on crustacean Daphnia magna and bacteria Vibrio fischeri. The infiltration of the leachates of both fly ashes through soil affected considerably their leaching profile. The transport of Cu and Zn was facilitated by the dynamic leaching conditions and influenced by the pH of the leachates. Moreover, the release and bioavailability of Cr, Cu and Zn was probably altered during the infiltration experiments and organisms' response was not always correlated with the concentration of metals. Nevertheless, the results are signalling that possible manipulations and final disposal of fly ash should be considered when environmental threats are investigated. PMID:26087643

  1. Organic sulfur removal from coal by electrolysis in alkaline media

    Energy Technology Data Exchange (ETDEWEB)

    Wapner, P.G.; Lalvani, S.B.; Awad, G.

    1988-03-01

    Coal slurries were electrolysed in a basic electrolyte (1M NaOH) in a batch reactor. Platinum gauze electrodes were employed which were separated by a porous teflon frit that confined coal particles to the anode compartment. A three-electrode potentiostatic technique was used to measure rates of reaction. The amount of sulfur removed was found to be strongly dependent on the electrode potential applied. Over 60% of the total sulfur content can be removed by electrolysis. Moreover, it appears higher cell potentials promote organic sulfur removal (70% at 1.8 to 2.0 V), while lower cell potentials promote pyritic sulfur removal (85% at 1.2 to 1.4 V). In addition, hydrogen gas was observed to be produced at the cathode at about half the potential required for conventional water electrolysis, with current efficiencies higher than 96%. The anodic current, and reaction rates increased monotonically with temperature. An apparent activation energy of 12.05 kcal/mol was calculated for coal oxidation in 1M NaOH solution at an applied potential of 1.2 V versus SCE. 11 refs., 7 figs., 6 tabs.

  2. An Evaluation on the Physical and Chemical Composition of Coal Combustion Ash and Its Co-Placement with Coal-Mine Waste Rock

    OpenAIRE

    Budi Sulistianto; Rudy S. Gautama; Candra Nugraha; Kikuo Matsui; Hideki Shimada; Takashi Sasaoka; Ginting J. Kusuma

    2012-01-01

    In the last few decades, the utilization of coal to generate electricity was rapidly increasing. Consequently, the production of coal combustion ash (CCA) as a by-product of coal utilization as primary energy sources was increased. The physical and geochemical characteristics of CCA were site-specific which determined by both inherent coal-source quality and combustion condition. This study was intended to characterize the physical, chemical and mineralogical properties of a coal-combustion a...

  3. Selenium bioaccumulation in fish exposed to coal ash at the Tennessee Valley Authority Kingston spill site.

    Science.gov (United States)

    Mathews, Teresa J; Fortner, Allison M; Jett, R Trent; Morris, Jesse; Gable, Jennifer; Peterson, Mark J; Carriker, Neil

    2014-10-01

    In December 2008, 4.1 million cubic meters of coal ash were released into the Emory and Clinch Rivers by the Tennessee Valley Authority Kingston Fossil Plant. Coal ash contains several contaminants, including the bioaccumulative metalloid selenium (Se). Because Se is predominantly accumulated in aquatic organisms through dietary rather than aqueous exposure, tissue-based toxicity thresholds for Se are currently being considered. The proposed threshold concentrations range between 4??g/g and 9??g/g Se (dry wt.) in whole body fish, with a proposed fillet threshold of 11.8??g/g. In the present study, the authors examined the spatial and temporal trends in Se bioaccumulation and examined the relationship between the Se content in fillets and in whole bodies of fish collected around the Kingston spill site to determine whether Se bioaccumulation was a significant concern at the ash spill site. Whereas Se concentrations in fish (whole bodies and fillets) were elevated at sampling locations affected by the Kingston ash spill relative to reference locations, concentrations do not appear to be above risk thresholds and have not been increasing over the 5-yr period since the spill. These findings are not only relevant to guiding the human health and ecological risk assessments at the Kingston ash spill site, but because of current national discussions on appropriate guidelines for Se in fish as well for the disposal of coal combustion wastes, the results are also relevant to the general understanding of Se bioaccumulation in contaminated water bodies. PMID:24943719

  4. Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health

    Directory of Open Access Journals (Sweden)

    J. Marvin Herndon

    2015-08-01

    Full Text Available The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1 Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2 Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1 the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test and identical variances (F-test; and (2 the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.

  5. A method of measuring the ash content of coal in moving wagons

    International Nuclear Information System (INIS)

    A method has been developed to determine the ash content of coal in moving wagons. It is based on an observed correlation between aluminium content and ash and on measurement of the aluminium content by neutron activation analysis using a 252Cf source. The effects of varying a number of important operational parameters which affect neutron flux distributions within the coal have been studied theoretically using Monte Carlo computer techniques. These parameters include ash content, water content, bulk density, the design of the source mounting and the source-detector separation. The effect of variations in wagon speed has also been studied. The results show the technique to be operationally viable and provide valuable data for the design of a working system. Experimental investigations using samples which are both small and large compared with neutron range have been carried out to confirm the theoretical results. They provide additional data on the effects of source-to-coal and detector-to-coal spacing and on the overall accuracy of the method. No additional error was detectable over and above that imposed by the ash-aluminium correlation. (author)

  6. Cobalt(II) removal from synthetic wastewater by adsorption on South African coal fly ash

    Scientific Electronic Library Online (English)

    Evans T., Musapatika; Maurice S., Onyango; Ochieng, Aoyi.

    2010-10-01

    Full Text Available Advanced wastewater-treatment techniques such as adsorption are essential in the removal of non-biodegradable toxic wastes from water. In this study, the use of South African coal fly ash, an industrial byproduct, has been investigated as a potential replacement for the current costly adsorbents use [...] d for removing heavy metals from wastewater. We utilised coal fly ash for the adsorption of cobalt(II) ions from synthetic petrochemical wastewater and characterised its performance. A two-level three-factor full-factorial design was successfully employed for experimental design and analysis of the results. The combined effects of pH, initial concentration and adsorbent dose on cobalt(II) removal were assessed using response surface methodology. Although the focus was on removal of cobalt(II), the adsorption was carried out in the presence of phenol and other heavy metal ions using the batch technique. The applicability of the Freundlich and Langmuir models to the equilibrium data was tested. Consequently, the equilibrium data was found to conform more favourably to the Freundlich isotherm than to the Langmuir isotherm; in this case, the coal fly ash had a maximum adsorption capacity of 0.401 mg/g for cobalt(II). We conclude that South African coal fly ash, as a natural, abundant and low-cost adsorbent, might be a suitable local alternative for elimination of cobalt(II) from aqueous solutions.

  7. Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health.

    Science.gov (United States)

    Herndon, J Marvin

    2015-08-01

    The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1) Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2) Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA) filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1) the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test) and identical variances (F-test); and (2) the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction. PMID:26270671

  8. Trace elements in lake sediment, macrozoobenthos, and fish near a coal ash disposal basin

    Science.gov (United States)

    Hatcher, Charles O.; Ogawa, Roann E.; Poe, Thomas P.; French, John R. P., III

    1992-01-01

    Samples of lake sediment, macrozoobenthos, and fish were collected during 1983 and 1984 near a coal ash disposal basin situated on the western shoreline of Lake Erie. Neutron activation analysis was used to determine if potentially toxic trace elements were present in higher concentrations at stations near the basin than at reference stations a few kilometers away.

  9. Improved leaching test methods for environmental assessment of coal ash and recycled materials used on construction

    Science.gov (United States)

    Changes in air pollution control at coal-fired power plants will result in lower emissions of mercury and other pollutants. Fly ash, flue gas desulfurization gypsum, and other air pollution control residues are used in agricultural, commercial, and engineering applications. Resea...

  10. Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

    Directory of Open Access Journals (Sweden)

    BORISLAV GRUBOR

    2003-02-01

    Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

  11. Leaching characteristics of coal and fly ash from Parichha Thermal Power Plant, Jhansi, U.P. (India)

    International Nuclear Information System (INIS)

    Nearly 73% of India's total installed power generation capacity is thermal based power plants, 90% of its coal-based thermal power plants. Coal-based thermal power plants produce approximately 100 million tones of fly ash annually. Indian coal is of poor quality with high ash contents (35-50%) and low calorific value (? 15 MJ/Kg). This results in higher coal consumption for each MW power. Power generation in India has increased 1362 MW in 1947 to about 1,38,251 MW in March 2009. India is worlds sixth largest energy consumer, accounting for 3.4% of global energy consumption. More than 80 Coal-based thermal power plants is producing 73,492.38 MW (53.15%) while 14,581.71 MW(10.54%) by Gas-based thermal power plants, 1,201.75 MW (0.069%) by Diesel-based thermal power plants, 10,175 MW (7.35%) by Wind power, 34,680.76 MW (25.08%) by Hydroelectric power and 4,120 MW (2.90%) by Nuclear power reactors. The use of coal in power generation has led to increasing environmental problems associated not only with gaseous emissions but also with the disposal of ash residues. In particular, the use of low quality coals with high ash content results in huge quantities of both fly ash and bottom ash to be disposed off. An important problem related to coal ash disposal is the heavy metal content of the residue. In this regard, experimental results of numerous studies indicate that toxic trace metals may leach when coal and fly ash come into contact with water. In this study, coal and fly ash samples obtained from Parichha Thermal Power plant, located about 25 km from Jhansi at Parichha in Jhansi of Uttar Pradesh, and were subjected to toxicity tests, namely, Toxicity Characteristic Leaching Procedure (TCLP) of the U.S. Environment Protection Agency (USEPA). (author)

  12. Assessment of ecotoxicological risks of element leaching from pulvarized coal ashes.

    OpenAIRE

    Jenner, H.A.

    1995-01-01

    This thesis describes the consequences of the disposal of the combustion residues of coal, especially the uptake of elements from such residues and their effects on various organisms. The effects on benthic organisms in fresh and in seawater are considered in the first two parts. The third part looks at the uptake of elements from coal residues and their effect on the growth of plants and worms.The central theme is the combustion residue known as pulverized fuel ash (PFA), or 'flyash'. Coal i...

  13. The Effect of Microwave Energy on Grindability of a Turkish High-Ash Coal

    OpenAIRE

    O. Y. Toraman; M.S. Del?balta

    2012-01-01

    In the present study, the effect of microwave energy on grindability of high-ash (46.39%) and sulphur (3.99%) Turkish coal has been investigated. Coal samples (-9.52+3.18 mm) was treated by microwave at a frequency of 2.45 GHz with different power levels (0.48-0.64-0.80 kW) and residence times (30-150 s.). In order to determine the crushing/grinding resistance of low ranked lignite coal samples treated by microwave oven, the Impact Strength Index (ISI) test was applied for each treat...

  14. PREFERENTIAL PARTITIONING OF PAHS AND PCBS TO COAL FLY ASH

    Science.gov (United States)

    It has long been known that fly ash has a significant capacity for the adsorption of several classes of anthropogenic pollutants, including toxic metals, nutrients and organic compounds. This adsorption capacity has been utilized by wastewater treatment plants for the removal of ...

  15. Coal fly ash utilization: Low temperature sintering of wall tiles

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, N.; Sharma, P.; Pashkov, G.L.; Voskresenskaya, E.N.; Amritphale, S.S.; Baghel, N.S. [CSIR, Bhopal (India). Regional Research Laboratory

    2008-07-01

    We present here a study of the sintering of fly ash and its mixture with low alkali pyrophyllite in the presence of sodium hexa meta phosphate (SHMP), a complex activator of sintering, for the purpose of wall the manufacturing. The sintering of fly ash with SHMP in the temperature range 925-1050{sup o}C produces tiles with low impact strength; however, the incremental addition of low alkali pyrophyllite improves impact strength. The impact strength of composites with {ge} 40% (w/w) pyrophyllite in the fly ash-pyrophyllite mix satisfies the acceptable limit (19.6 J/m) set by the Indian Standards Institute for wall tiles. Increasing the pyrophyllite content results in an increase in the apparent density of tiles, while shrinkage and water absorption decrease. The strength of fly ash tiles is attributed to the formation of a silicophosphate phase; in pyrophyllite rich tiles, it is attributed to the formation of a tridymite-structured T-AlPO{sub 4} phase. Scanning electron micrographs show that the reinforcing rod shaped T-AlPO{sub 4} crystals become more prominent as the pyrophyllite content increases in the sintered tiles.

  16. Coal fly ash utilization: Low temperature sintering of wall tiles

    International Nuclear Information System (INIS)

    We present here a study of the sintering of fly ash and its mixture with low alkali pyrophyllite in the presence of sodium hexa meta phosphate (SHMP), a complex activator of sintering, for the purpose of wall tile manufacturing. The sintering of fly ash with SHMP in the temperature range 925-1050 deg. C produces tiles with low impact strength; however, the incremental addition of low alkali pyrophyllite improves impact strength. The impact strength of composites with ?40% (w/w) pyrophyllite in the fly ash-pyrophyllite mix satisfies the acceptable limit (19.6 J/m) set by the Indian Standards Institute for wall tiles. Increasing the pyrophyllite content results in an increase in the apparent density of tiles, while shrinkage and water absorption decrease. The strength of fly ash tiles is attributed to the formation of a silicophosphate phase; in pyrophyllite rich tiles, it is attributed to the formation of a tridymite-structured T-AlPO4 phase. Scanning electron micrographs show that the reinforcing rod shaped T-AlPO4 crystals become more prominent as the pyrophyllite content increases in the sintered tiles

  17. Melting Behavior of ashes from the co-combustion of coal and straw

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Frandsen, Flemming

    2007-01-01

    Straw may be used today as a substitute fuel to lower the greenhouse gas emissions from traditional coalfired power plants and provide green-based electricity. It may also provide an alternative source of income to the local farmers helping the developed countries to support sustainable development. The use of straw as a co-firing feedstock in traditional coal-fired plants is associated with operational problems, such as deposition, agglomeration, and/or corrosion, mainly because of the higher amounts of alkali metals and chlorine in straw compared to coal. This may lead to unscheduled shutdowns and costly repairs, increasing the operational costs and the cost of the produced power. In this paper, the melting characteristics of several ash fractions sampled from different parts of a pilot-scale pulverized fuel (PF) boiler operating with different coal/straw mixtures is determined by measuring the ash viscosity using a high-temperature rotational viscometer. The produced data provide information on the meltingof the ash material, its flow characteristics, and the rates of crystallization and recrystallization, as a function of the temperature. This information may be used to modify the temperature profile in the different parts of the boiler to reduce the deposition of the ash material. The results show that the straw in the co-combustion mixture changes the viscosity characteristics of the produced ash fractions. The viscosity of the different ash fractions is lowered, as the percentage of straw in the cocombustion mixture increases, and leads to higher stickiness of the produced ash particles at lower temperatures.

  18. Production of novel ceramic materials from coal fly ash and metal finishing wastes

    Energy Technology Data Exchange (ETDEWEB)

    Little, M.R.; Adell, V.; Cheeseman, C.R. [Centre for Environmental Control and Waste Management, Department of Civil and Environmental Engineering, Skempton Building, Imperial College London, London SW7 2AZ (United Kingdom); Boccaccini, A.R. [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2BP (United Kingdom)

    2008-09-15

    Fly ash from coal fired power stations is a potential raw material for the production of ceramic tiles, bricks and blocks. Previous work has demonstrated that the addition of metals can significantly alter fly ash sintering. Metal finishing produces problematic waste filter cakes and sludges that are increasingly difficult to dispose of to landfill. The objective of this research was to investigate the effect of selected metal finishing wastes on the properties of sintered fly ash. A 10 wt.% addition of dried metal finishing sludge obtained from the phosphate bath at a tri-cationic phosphating operation significantly reduced the sintering temperature for maximum density by approximately 75 C. The addition of the phosphate bath sludge also reduced leaching of As, to the extent that fly ash ceramics containing this waste would be classified as inert. Potential industrial applications for these novel waste-derived ceramic materials are discussed. (author)

  19. Feasibility of fly ash-based composite coagulant for coal washing wastewater treatment

    International Nuclear Information System (INIS)

    Highlights: ? Coal washing wastewater was analyzed. ? Several fly ash-based composite coagulants were prepared to treat coal washing wastewater. ? The effluent with the high COD and SS removal was obtained after treatment. - Abstract: In this study, several fly ash (FA)-based composite coagulants, leached by hydrochloric acid, were prepared to treat coal washing wastewater. The concentrations of Al3+ and Fe2+/Fe3+ in the leachates and coagulants were analyzed, and optimal experimental conditions, including coagulant dosage and initial pH, were determined using various analytical techniques (scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction (XRD), X-ray fluorescence (XRF), particle-size analysis, zeta potential, pH and conductivity measurements). A suspended solids (SS) and chemical oxygen demand (COD) removal efficiency from the effluent treated by one of the coagulants reached 99.61% and 96.48%, respectively, at dosages of 10 g l?1 (initial pH of 9, adjusted by CaO). This indicates that the coagulant was an effective agent for coal washing wastewater treatment, and that the leached Al3+ and Fe3+ and introduced Ca2+ may have improved the coagulation process. Analysis of the dry sludge composition and slurry particle size distribution of the coal washing wastewater showed that charged colloidal particles and the fine particle distribution in the coal washing wastewater make the wastewater treatment a difficult process. Results from this study could provide a novel approach for the treatment of coal washing wastewater and coal fly ash utilization.

  20. Changes in growth characters and nutrient acquisition of guava (psidium guajava l.) in response to coal ash

    International Nuclear Information System (INIS)

    Coal ash management would remain a great concern all over the world. Several studies proposed that there is an ample scope for safe utilization of coal ash as a soil ameliorant that may improve physical, chemical and biological properties of the soil and is a source of readily available plant micro and macro nutrient. With this concept a pot culture experiment was carried out in the eastern ghat high land zone of Odisha, India under open condition in the nursery. Different levels of coal ash and soil mixture were used in different combinations to check their effect on the physio-morphological and biochemical parameters of guava. The study on the effect of varying levels of coal ash on guava revealed that the combination of 50:50 and 25:75 coal ash and soil mixture increased the seed germination, seedling characteristics, biomass, vegetative growth and chlorophyll content of the seedlings. The increase in growth traits was attributed to increase in nutrient acquisition of plants grown under above combinations. On contrary 100% coal ash in the growing medium reduced seed germination, seedling vigour, growth and biomass per plant. The leaf nutrient status of N, P, K, Ca, Mg, S and the micro nutrients Zn, Mn, B, Mo, Fe and Cu were found to be higher in the treatments having higher proportion of coal ash in the growing medium than other treatments and the lowest was recorded in control ( no coal ash). The findings suggest that application of coal ash in certain proportion is beneficial in terms of growth parameters and nutrient acquisition in guava. (author)

  1. Predicting Water Quality Problems Associated with Coal Fly Ash Disposal Facilities Using a Trace Element Partitioning Study

    Science.gov (United States)

    Bhattacharyya, S.; Donahoe, R. J.; Graham, E. Y.

    2006-12-01

    For much of the U.S., coal-fired power plants are the most important source of electricity for domestic and industrial use. Large quantities of fly ash and other coal combustion by-products are produced every year, the majority of which is impounded in lagoons and landfills located throughout the country. Many older fly ash disposal facilities are unlined and have been closed for decades. Fly ash often contains high concentrations of toxic trace elements such as arsenic, boron, chromium, molybdenum, nickel, selenium, lead, strontium and vanadium. Trace elements present in coal fly ash are of potential concern due to their toxicity, high mobility in the environment and low drinking water MCL values. Concern about the potential release of these toxic elements into the environment due to leaching of fly ash by acid rain, groundwater or acid mine drainage has prompted the EPA to develop national standards under the subtitle D of the Resource Conservation and Recovery Act (RCRA) to regulate ash disposal in landfills and surface impoundments. An attempt is made to predict the leaching of toxic elements into the environment by studying trace element partitioning in coal fly ash. A seven step sequential chemical extraction procedure (SCEP) modified from Filgueiras et al. (2002) is used to determine the trace element partitioning in seven coal fly ash samples collected directly from electric power plants. Five fly ash samples were derived from Eastern Bituminous coal, one derived from Western Sub-bituminous coal and the other derived from Northern Lignite. The sequential chemical extraction procedure gives valuable information on the association of trace elements: 1) soluble fraction, 2) exchangeable fraction, 3) acid soluble fraction, 4) easily reducible fraction, 5) moderately reducible fraction, 6) poorly reducible fraction and 7) oxidizable organics/sulfide fraction. The trace element partitioning varies with the composition of coal fly ash which is influenced by the type of coal burned. Preliminary studies show that in some fly ash samples, significant amounts of As, B, Mo, Se, Sr and V are associated with the soluble and exchangeable fraction, and thus would be highly mobile in the environment. Lead, on the other hand, is mainly associated with the amorphous Fe and Mn oxide fractions and would be highly immobile in oxidizing conditions, but mobile in reducing conditions. Ni and Cr show different associations in different fly ash samples. In most fly ash samples, significant amounts of the trace elements are associated with more stable fractions that do not threaten the environment. The study of trace element partitioning in coal fly ash thus helps us to predict their leaching behavior under various conditions.

  2. Coal fly ash-slag-based geopolymers: Microstructure and metal leaching

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, Maria, E-mail: mariaizq@ija.csic.es [Institute of Earth Sciences ' Jaume Almera' -CSIC, Lluis Sole Sabaris s/n 08028 Barcelona (Spain); Querol, Xavier [Institute of Earth Sciences ' Jaume Almera' -CSIC, Lluis Sole Sabaris s/n 08028 Barcelona (Spain); Davidovits, Joseph [Cordi-Geopolymere, Espace Creatis, Z.A. Bois de la Chocque 02100 Saint-Quentin (France); Antenucci, Diano [Institut Scientifique de Service Public (ISSeP) 200, rue du Chera, B-4000 Liege (Belgium); Nugteren, Henk [Delft University of Technology, Faculty of Applied Sciences, DelftChemTech, Particle Technology Group, Julianalaan 136, 2628 BL Delft (Netherlands); Fernandez-Pereira, Constantino [University of Seville, School of Industrial Engineering, Department of Chemical and Environmental Engineering, Camino de los Descubrimientos s/n, 41092 Seville (Spain)

    2009-07-15

    This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilise a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

  3. Coal fly ash-slag-based geopolymers: Microstructure and metal leaching

    International Nuclear Information System (INIS)

    This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilise a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.

  4. Coal fly ash-slag-based geopolymers: microstructure and metal leaching.

    Science.gov (United States)

    Izquierdo, Maria; Querol, Xavier; Davidovits, Joseph; Antenucci, Diano; Nugteren, Henk; Fernández-Pereira, Constantino

    2009-07-15

    This study deals with the use of fly ash as a starting material for geopolymeric matrices. The leachable concentrations of geopolymers were compared with those of the starting fly ash to evaluate the retention of potentially harmful elements within the geopolymer matrix. Geopolymer matrices give rise to a leaching scenario characterised by a highly alkaline environment, which inhibits the leaching of heavy metals but may enhance the mobilization of certain oxyanionic species. Thus, fly ash-based geopolymers were found to immobilize a number of trace pollutants such as Be, Bi, Cd, Co, Cr, Cu, Nb, Ni, Pb, Sn, Th, U, Y, Zr and rare earth elements. However, the leachable levels of elements occurring in their oxyanionic form such as As, B, Mo, Se, V and W were increased after geopolymerization. This suggests that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation. PMID:19118943

  5. Mixtures of coal ash and compost as substrates for highbush blueberry

    Energy Technology Data Exchange (ETDEWEB)

    Black, B.L.; Zimmerman, R.H. [ARS, Beltsville, MD (USA). USDA Henry A Wallace Beltsville Agriculture Research Center, Fruit Lab.

    2002-07-01

    Bottom ash from a coal-fired power plant and two composts were tested as components of soil-free media and as soil amendments for growing highbush blueberry (Vaccinium corymbosum L.). Combinations of ash and compost were compared to Berryland sand, and Manor clay loam, and compost amended Manor clay loam. The pH of all treatment media was adjusted to 4.5 with sulfur at the beginning of the experiment. In 1997, plants of 'Bluecrop' and 'Sierra' were planted in 15-dm{sup 3} pots containing the pH-adjusted treatment media. The first substantial crop was harvested in 1999. At the end of the 1999 season, one half of the plants were destructively harvested for growth analysis. The remaining plants were cropped again in 2000. Yield and fruit size data were collected in both seasons, and leaf and fruit samples were collected in 1999 for elemental analysis. The presence of coal ash or composted biosolids in the media had no detrimental effect on leaf or fruit elemental content. Total growth and yield of both cultivars was reduced in clay loam soil compared to Berryland sand, whereas growth and yield of plants in coal ash-compost was similar to or exceeded that of plants in Berryland sand.

  6. Glass Ceramics Composites Fabricated from Coal Fly Ash and Waste Glass

    International Nuclear Information System (INIS)

    Great quantities of coal ash are produced in thermal power plants which present a double problem to the society: economical and environmental. This waste is a result of burning of coal at temperatures between 1100-14500C. Fly ash available as fine powder presents a source of important oxides SiO2, Al2O3, Fe2O3, MgO, Na2O, but also consist of small amount of ecologically hazardous oxides such as Cr2O3, NiO, MnO. The combination of the fly ash with waste glass under controlled sintering procedure gave bulk glass-ceramics composite material. The principle of this procedure is presented as a multi barrier concept. Many researches have been conducted the investigations for utilization of fly ash as starting material for various glass–ceramics production. Using waste glass ecologically hazardous components are fixed at the molecular level in the silicate phase and the fabricated new glass-ceramic composites possess significantly higher mechanical properties. The aim of this investigation was to fabricate dense glass ceramic composites using fly ash and waste glass with the potential for its utilization as building material

  7. Hydrothermal synthesis of belite cement from coal fly ashes with various CaO content

    International Nuclear Information System (INIS)

    This paper summarizes the results of hydrothermal synthesizing belite cement from reactive mixtures consisting of two waste kinds (bottom ash and fly ash) from fluidized brown coal combustion in Slovakian power plant and CaO (analytical grade reagent) addition with CaO/SiO2 molar ratio of 2 in rotating autoclave under various conditions (175 a 200 grad C; 2 and 4 hours; water and 0.2 and 0.5 % NaOH solution). Changes in structure and phase composition of hydrothermally synthesized belite precursors and subsequent calcinated products were compared with those of starting mixtures. Based on XRD diffraction patterns and infrared spectra of pre-treatment products, the formation of the new profiles corresponding to CSH and ?-C2SH phases with low degree of ordering as belite precursors after hydrothermal treatment was confirmed. Optimal conditions of hydrothermal treatment of reactive mixtures were 200 grad C and 4 hours in water. Different phase composition of products before and after calcination depends upon waste quality and precursor's synthesis conditions. Optimal calcination temperature in term of product quality to belite in precursors prepared by hydrothermal treatment of reactive mixture based on fly ash is 800 grad C because gehlenite as cement hydration retarder isn't formed at this temperature. Evaluation of phase composition in hydrothermally treated products of reactive mixtures showed that bottom ash with high CaO content fixed in anhydrite form (44.1 %) as a very stable compound is not suitable as raw material for synthesizing belite phase whereas coal fly ash with low CaO content in anhydrite form (4.2 %) and its hydrothermal treatment in combination with subsequent heating offer opportunities for the utilization of coal fly ash as raw material for belite production. (authors)

  8. Suppression of fine ash formation in pulverized coal flames. Final technical report, September 30, 1992--January 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kramlich, J.C.; Chenevert, B.; Park, Jungsung; Hoffman, D.A.; Butcher, E.K.

    1996-07-19

    Coal ash, and particularly fine fly ash, remain one of the principal practical and environmental problems in coal-based power generation. In particular, submicron aerosols are identified with direct inhalation risk. Submicron ash is thought to arise from mineral vaporization during char combustion, followed by nucleation, condensation and coagulation to yield an aerosol. While aerosols are predominantly made out of volatile alkali minerals, they also can include refractory oxides that are chemically reduced to more volatile forms within the char particle and vaporized. Most of the ash of size greater than 1 {mu}m is generated by agglomeration of mineral as the char particle bums out. These two principal mechanisms are thought to account for most of the ash generated in coal combustion. Previous research has shown that various forms of coal treatment can influence the yields of fine ash from combustion. The research reported here investigates various forms of treatment, including physical coal cleaning, aerodynamic sizing, degree of grinding, and combinations of these on both aerosol yields and on yields of fine residual ash (1-4 {mu}m). The work also includes results from the combustion of artificial chars that include individual mineral elements. This research shows that these various forms of coal treatment can significantly change ash characteristics. While none of the treatments affected the bulk of the residual ash size distribution significantly, the yield of the ash aerosol mode (d<0.5 {mu}m) and fine residual ash mode (1-4 {mu}m) are changed by the treatments.

  9. Nitric Oxide Removal From Flue Gases By Carbon-enriched Coal Fly Ash

    OpenAIRE

    Begoña Rubio; Maria Teresa Izquierdo

    2013-01-01

    The aim of this work is to evaluate the characteristics of activated and non-activated carbon obtained from carbon-enriched coal fly ashes (CECFA) from two different power stations to be used in the low temperature reduction of NO from stack gases. Carbon-rich fractions were obtained by mechanical sieving of fly ashes and by oil agglomeration. Activation of some samples was carried out in steam at 900ºC in order to develop porosity onto the samples. The obtained activated and non-activated sa...

  10. Mercury capture by native fly ash carbons in coal-fired power plants

    OpenAIRE

    Hower, James C.; Senior, Constance L.; Suuberg, Eric M.; Hurt, Robert H; Wilcox, Jennifer L.; Olson, Edwin S.

    2010-01-01

    The control of mercury in the air emissions from coal-fired power plants is an on-going challenge. The native unburned carbons in fly ash can capture varying amounts of Hg depending upon the temperature and composition of the flue gas at the air pollution control device, with Hg capture increasing with a decrease in temperature; the amount of carbon in the fly ash, with Hg capture increasing with an increase in carbon; and the form of the carbon and the consequent surface area of the carbon, ...

  11. Hydrothermal Synthesis of Zeolite from Coal Class F Fly Ash. Influence of Temperature

    Directory of Open Access Journals (Sweden)

    Goñi, S.

    2010-06-01

    Full Text Available The influence of temperature of alkaline hydrothermal treatment on the conversion in zeolite of Spanish coal low calcium-fly ash (ASTM class F is presented in this work. Zeolite Na-P1 gismondine type (Na6Al6Si10O32.12H2O was formed at the temperature of 100ºC, which transformed in zeolite; analcime-C type (Na(Si2AlO6H2O and sodalite (1.08 Na2O.Al2O3.1.68SiO2.1.8H2O at 200ºC together with traces of tobermorite-11Å (Ca5(OH2Si6O16.4H2O. At this temperature the 100% of the fly ash reaction was allowed. An equivalent study was carried out in water as reference. The zeolite conversion of the fly ash was characterized by X ray diffraction (XRD, FT infrared (FTIR spectroscopy, surface area (BET-N2 and thermal analyses.

    En este trabajo se presenta el papel que juega la temperatura durante el tratamiento hidrotermal en medio alcalino para convertir una ceniza volante de bajo contenido en cal (clase F, según la norma ASTM en zeolita. Durante este tratamiento a la temperatura de 100ºC se forma Zeolita Na-P1 tipo gismondina (Na6Al6Si10O32.12H2O; al elevar la temperatura a 200ºC, dicha zeolita se transforma en zeolita Analcima C (Na(Si2AlO6H2O y en fase sodalita (1.08 Na2O.Al2O3.1.68SiO2.1.8H2O junto con trazas de tobermorita-11Å (Ca5(OH2Si6O16.4H2O. A esta temperatura y en estas condiciones se ha conseguido un 100% de reacción. Un estudio equivalente se ha llevado a cabo empleando agua como medio de referencia. La conversión de ceniza volante en zeolita se ha caracterizado mediante técnicas, como difracción de Rayos X (DRX, espectroscopia infrarroja por transformada de Fourier (FTIR y análisis térmico (TG/ATD; así mismo los cambios en el área superficial se han llevado a cabo mediante la técnica BET-N2.

  12. Effects of inhaled coal fly ash on lung biochemistry and function in guinea pigs

    International Nuclear Information System (INIS)

    The ultrafine fraction of particles produced during the combustion of coal are the most difficult to remove with control devices and are retained longest in the atmosphere. Combustion of a high-sulfur coal, such as Illinois No. 6, produces a significant quantity of sulfuric acid, most of which is absorbed to the surface of those particles smaller than 1 ?m in diameter. Particles smaller than 0.05 ?m in diameter, moreover, consist largely of sulfuric acid; since these particles penetrate to the deepest regions of the lung, exposure to coal fly ash can result in the administration of large doses of acid to the alveolar tissues. Using a combustion system that generates coal fly ash similar to that collected in flue gas, guinea pigs were exposed for 2 h to aerosols produced from Illinois No. 6 (mean aerodynamic diameter 0.2 ?m) at concentrations of 5 and 20 mg/m3. The animals were lavaged at 24 h post-exposure and levels of dehydrogenase (LDH), ?-glucuronidase (?-GC), and protein were compared to those of control animals. After 24 h, no changes in levels of LDH and ?-GC were seen in the lavage fluid from both high-dose and low-dose animals. Slight, but statistically significant elevations in protein concentration were measured in the high-dose exposure group. The total cell number in the lavage fluid was also found exposure group. The total cell number in the lavage fluid was also found to be exchanged following both exposures. It was previously found that exposure to 5 mg/M3 of Illinois No. 6 fly ash results in immediate reductions in pulmonary diffusing capacity (DLco), total lung capacity (TLC), and vital capacity, and that both DLco and TLC values are not completely restored to normal 96 h post-exposure. These results suggest that the alterations in pulmonary function resulting from exposure to acidic coal fly ash are not accompanied by major inflammatory changes in lavage fluid

  13. Experimental study of fly ash of Lakhra coal power plant in RCC beams

    International Nuclear Information System (INIS)

    Of the various industrial by-products, fly ash, a finely divided mineral residue generated from the combustion of pulverized coal in power plants, is the most abundant. Its utilization as mineral admixture in cement concrete transforms a costly liability into an economical proposition. Further more, the costs and environmental problems associated with its disposal are minimized or eliminated. This study comprises on RCC beams made with ordinary Portland cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of present study, total 27 RCC beams were made. Among 27 beams, 3 beams were made with normal concrete, 12 beams were made by replacing 25, 50, 75 and 100% of fine aggregate by fly ash and 12 beams were made by replacing 10, 25, 50, and 75% of cement by fly ash. The study of these beams was carried out in terms of Load deflection, ultimate strength, crack pattern and failure mode. By analyzing the test results, it was observed that the beams made by replacing 75% of fine aggregate by fly ash with 4 and 6 stirrups has shown less deflection and higher ultimate load carrying capacity whereas the beams made by replacing 50 and 75% of-cement by fly ash have given inferior behaviour in comparison to the beam made by ordinary portland cement concrete. (author)

  14. Investigations of the solidifying process of ash slurries from Belchatow coal

    Energy Technology Data Exchange (ETDEWEB)

    Giergiczny, Z.; Michniewicz, E. (Instytut Mineralnych Materialow Budowlanych, Opole (Poland))

    1991-01-01

    Discusses properties of fly ash from combustion of brown coal from the Belchatow surface mines, as well as hardening of fly ash slurries. Fly ash from Belchatow is characterized by a high content of calcium oxides (including free calcium oxides), silicon oxides and aluminium oxides as well as relatively high sulfur trioxide content. Content of calcium oxides ranges from 6.5% to 28.8%. With increasing calcium oxide content in the fly ash, content of free calcium oxides also increases and silica content declines. Mechanical properties (compression strength) of hardened fly ash mixed with water were measured after 7 and 28 days. Effects of weathering, moisture content and temperature on fly ash compression strength were analyzed. Evaluations showed that a high content of free calcium oxide negatively influences compression strength of the samples. This phenomenon could be controlled by the use of additives. Sample compression strength was increased by an alkali environment, by reducing contact with carbon dioxide from the air and by preventing sample dehydration. 8 refs.

  15. Experimental study on the rheological behaviour of coal ash slurries

    Directory of Open Access Journals (Sweden)

    Assefa K.M.

    2015-12-01

    Full Text Available Extensive experimental investigations were carried out to evaluate the rheological behaviour of fly ash (FA slurry without and with the addition of bottom ash (BA and BA slurry without and with the addition of FA. The FA slurries exhibited Bingham behaviour at solid mass concentrations ranging from 60–65% and mixing proportions from 10– 40%. A substantial reduction in yield stress was observed except for mixing proportion of 40% on which the yield stress and viscosity were increased drastically for all solid concentrations. Hence, it can be concluded that the yield stress and viscosity of FA slurry were very much influenced by adding BA up to the mixing proportion of 30%. The rheological behaviour of BA slurries with and without the addition of FA in proportions of 10–50% was investigated and exhibited Newtonian behaviours for solid mass concentrations ranging from 30–50% without and with the addition of FA. The viscosity increases with increasing the solid concentrations and proportion of FA. Based on these experimental data, a correlation was developed to predict the relative viscosity of BA slurries as a function of solid volume fraction and FA mass proportion of 0–50% and the RMSE and R2 values showed good agreement between the experimental and the predicted data.

  16. EVALUATION OF THE EFFECTS OF COAL FLY ASH AMENDMENTS ON THE TOXICITY OF A CONTAMINATED MARINE SEDIMENT

    OpenAIRE

    Burgess, Robert M; Perron, Monique M.; Friedman, Carey L.; Suuberg, Eric M.; Pennell, Kelly G.; Cantwell, Mark G.; Pelletier, Marguerite C.; Ho, Kay T.; Serbst, Jonathan R.; Ryba, Stephan A.

    2009-01-01

    Approaches for cleaning-up contaminated sediments range from dredging to in situ treatment. In the present report, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7 d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ash...

  17. Effects of fluxing agents on gasification reactivity and gas composition of high ash fusion temperature coal

    Directory of Open Access Journals (Sweden)

    Zhao Ruifang

    2015-01-01

    Full Text Available A Na-based fluxing agent Na2O (NBFA and a composite fluxing agent (mixture of CaO and Fe2O3 with mass ratio of 3:1, CFA for short were used to decrease the ash fusion temperature of the Dongshan and Xishan coal from Shanxi of China and make these coal meet the requirements of the specific gasification process. The main constituents of the fluxing agents used in this study can play a catalyst role in coal gasification. So it is necessary to understand the effect of fluxing agents on coal gasification reactivity and gas composition. The results showed that the ash fusion temperature of the two coal used decreased to the lowest point due to the eutectic phenomenon when 5 wt% of CFA or NBFA was added. Simultaneously, the gas molar ratio of H2/CO changed when CFA was added. A key application was thus found where the gas molar ratio of H2/CO can be adjusted by controlling the fluxing agent amount to meet the synthetic requirements for different chemical products.

  18. Relative availability of selected trace elements from coal fly ash and Lake Michigan sediment

    Energy Technology Data Exchange (ETDEWEB)

    Alberts, J. J.; Burger, J.; Kalhorn, S.; Seils, C.; Tisue, T.

    1977-01-01

    The concentration of greater than 1 ..mu..m coal fly ash particles in Lake Michigan surface waters was found to be 10/sup 5/ to 10/sup 6/ per liter. With an expected residence time of one year, this concentration implies a flux to the sediment of 10/sup 6/ to 10/sup 7/ particles/cm/sup 2//yr, or about 10/sup -6/ to 10/sup -5/ g/cm/sup 2//yr. The release of trace elements from fly ash and sediment has been studied using Chelex-100 resin to simulate leaching at high dilutions in natural media. Mn, Pb and Zn, but not Fe, are released more readily from Lake Michigan sediment than from fly ash.

  19. Removal of toxic and alkali/alkaline earth metals during co-thermal treatment of two types of MSWI fly ashes in China.

    Science.gov (United States)

    Yu, Jie; Qiao, Yu; Jin, Limei; Ma, Chuan; Paterson, Nigel; Sun, Lushi

    2015-12-01

    This study aims to vaporize heavy metals and alkali/alkaline earth metals from two different types of fly ashes by thermal treatment method. Fly ash from a fluidized bed incinerator (HK fly ash) was mixed with one from a grate incinerator (HS fly ash) in various proportions and thermally treated under different temperatures. The melting of HS fly ash was avoided when treated with HK fly ash. Alkali/alkaline earth metals in HS fly ash served as Cl-donors to promote the vaporization of heavy metals during thermal treatment. With temperature increasing from 800 to 900°C, significant amounts of Cl, Na and K were vaporized. Up to 1000°C in air, less than 3% of Cl and Na and less than 5% of K were retained in ash. Under all conditions, Cd can be vaporized effectively. The vaporization of Pb was mildly improved when treated with HS fly ash, while the effect became less pronounced above 900°C. Alkali/alkaline earth metals can promote Cu vaporization by forming copper chlorides. Comparatively, Zn vaporization was low and only slightly improved by HS fly ash. The low vaporization of Zn could be caused by the formation of Zn2SiO4, ZnFe2O4 and ZnAl2O4. Under all conditions, less than 20% of Cr was vaporized. In a reductive atmosphere, the vaporization of Cd and Pb were as high as that in oxidative atmosphere. However, the vaporization of Zn was accelerated and that of Cu was hindered because the formation of Zn2SiO4, ZnFe2O4 and ZnAl2O4 and copper chloride was depressed in reductive atmosphere. PMID:26303652

  20. Application of multivariate linear regression for determination of ash content in coal by XRF analysis

    International Nuclear Information System (INIS)

    Measurements of excited and backscattered fluorescence radiation intensity were applied for ash content determination in coal samples. An Si(Li) detector and low energy X- and gamma ray sources 55Fe, 109Cd, 238Pu, 241Am were used. The measurement facility, consisting of an argon filled proportional counter and a 238Pu radiation source, was tested and compared with other radioanalytical methods for ash content determination. The evaluation of results was based on the Snedecor F test and the analysis of the rootmean square of estimate. The best results were obtained when 55Fe source was used. In the multivariate linear regression independent variables SiK?, CaK? and backscattered radiation intensities have been selected as variables that are best related with content in coal. (author)

  1. Synthesis and characterization of zeolite material from coal ashes modified by surfactant

    International Nuclear Information System (INIS)

    Coal ash was used as starting material for zeolite synthesis by means of hydrothermal treatment. The surfactant-modified zeolite (SMZ) was prepared by adsorbing the cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) on the external surface of the zeolite from coal ash. The zeolite structure stability was monitored during the characterization of the materials by FTIR, XDR and SEM. The structural parameters of surfactant-modified zeolite are very close to that of corresponding non-modified zeolite which indicates that the crystalline nature of the zeolite remained intact after required chemical treatment with HDTMA-Br molecules and heating treatment for drying. The most intense peaks in the FTIR spectrum of HDTMA-Br were observed in SMZ spectrum confirming adsorption of surfactant on zeolites. (author)

  2. Lognormal distribution of natural radionuclides in freshwater ecosystems and coal-ash repositories

    International Nuclear Information System (INIS)

    This study summarizes and analyses data for natural radionuclides, 40K, 226 Ra and 'Th, measured by gamma spectrometry in water samples, sediments and coal-ash samples collected from regional freshwater ecosystems and near-by coal-ash repositories during the last decade, 1986-1996, respectively. The frequency plots of natural radionuclide data, for which the hypothesis of the regional scale log normality was accepted, exhibited single population groups with exception of 226Ra and232Th data for waters. Thus the presence of break points in the frequency distribution plots indicated that 226Ra and 232Th data for waters do not come from a single statistical population. Thereafter the hypothesis of log normality was accepted for the separate population groups of 226 Ra and '-32 Th in waters. (authors)

  3. Arsenic and copper stabilisation in a contaminated soil by coal fly ash and green waste compost.

    Science.gov (United States)

    Tsang, Daniel C W; Yip, Alex C K; Olds, William E; Weber, Paul A

    2014-09-01

    In situ metal stabilisation by amendments has been demonstrated as an appealing low-cost remediation strategy for contaminated soil. This study investigated the short-term leaching behaviour and long-term stability of As and Cu in soil amended with coal fly ash and/or green waste compost. Locally abundant inorganic (limestone and bentonite) and carbonaceous (lignite) resources were also studied for comparison. Column leaching experiments revealed that coal fly ash outperformed limestone and bentonite amendments for As stabilisation. It also maintained the As stability under continuous leaching of acidic solution, which was potentially attributed to high-affinity adsorption, co-precipitation, and pozzolanic reaction of coal fly ash. However, Cu leaching in the column experiments could not be mitigated by any of these inorganic amendments, suggesting the need for co-addition of carbonaceous materials that provides strong chelation with oxygen-containing functional groups for Cu stabilisation. Green waste compost suppressed the Cu leaching more effectively than lignite due to the difference in chemical composition and dissolved organic matter. After 9-month soil incubation, coal fly ash was able to minimise the concentrations of As and Cu in the soil solution without the addition of carbonaceous materials. Nevertheless, leachability tests suggested that the provision of green waste compost and lignite augmented the simultaneous reduction of As and Cu leachability in a fairly aggressive leaching environment. These results highlight the importance of assessing stability and remobilisation of sequestered metals under varying environmental conditions for ensuring a plausible and enduring soil stabilisation. PMID:24859701

  4. An investigation of radon exhalation rate and estimation of radiation doses in coal and fly ash samples

    Energy Technology Data Exchange (ETDEWEB)

    Mahur, A.K.; Kumar, R.; Mishra, M.; Sengupta, D.; Prasad, R. [Aligarh Muslim University, Aligarh (India)

    2008-03-15

    Coal is a technologically important material used for power generation. Its cinder (fly ash) is used in the manufacturing of bricks, sheets, cement, land filling etc. Coal and its by-products often contain significant amounts of radionuclides, including uranium which is the ultimate source of the radioactive gas radon. Burning of coal and the subsequent atmospheric emission cause the redistribution of toxic radioactive trace elements in the environment. In the present study, radon exhalation rates in coal and fly ash samples from the thermal power plants at Kolaghat (W.B.) and Kasimpur (U.P.) have been measured using sealed Can technique having LR-115 type II detectors. The activity concentrations of U-238, Th-232, and K-40 in the samples of Kolaghat power station are also measured. It is observed that the radon exhalation rate from fly ash samples from Kolaghat is higher than from coal samples and activity concentration of radionuclides in fly ash is enhanced after the combustion of coal. Fly ash samples from Kasimpur show no appreciable change in radon exhalation. Radiation doses from the fly ash samples have been estimated from radon exhalation rate and radionuclide concentrations.

  5. Photosynthetic pigment concentrations, gas exchange and vegetative growth for selected monocots and dicots treated with two contrasting coal fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    Yunusa, I.A.M.; Burchett, M.D.; Manoharan, V.; DeSilva, D.L.; Eamus, D.; Skilbeck, C.G. [University of Technology Sydney, Sydney, NSW (Australia). Dept. of Environmental Science

    2009-07-15

    There is uncertainty as to the rates of coal fly ash needed for optimum physiological processes and growth. In the current study we tested the hyothesis that photosynthetic pigments concentrations and CO{sub 2} assimilation (A) are more sensitive than dry weights in plants grown on media amended with coal fly ash. We applied the Terrestrial Plant Growth Test (Guideline 208) protocols of the Organization for Economic Cooperation and Development (OECD) to monocots (barley (Hordeum vulgare) and ryegrass (Secale cereale)) and dicots (canola (Brasica napus), radish (Raphanus sativus), field peas (Pisum sativum), and lucerne (Medicago sativa)) on media amended with fly ashes derived from semi-bituminous (gray ash) or lignite (red ash) coals at rates of 0, 2.5, 5.0, 10, or 20 Mg ha(-1). The red ash had higher elemental concentrations and salinity than the gray ash. Fly ash addition had no significant effect on germination by any of the six species. At moderate rates ({<=}10 Mg ha{sup -1}) both ashes increased (P < 0.05) growth rates and concentrations of chlorophylls a and b, but reduced carotenoid concentrations. Addition of either ash increased A in radish and transpiration in barley. Growth rates and final dry weights were reduced for all of the six test species when addition rates exceeded 10 Mg ha{sup -1} for gray ash and 5 Mg ha{sup -1} for red ash. We concluded that plant dry weights, rather than pigment concentrations and/or instantaneous rates of photosynthesis, are more consistent for assessing subsequent growth in plants supplied with fly ash.

  6. Characterization of bottom ashes from coal pulverized power plants to determine their potential use feasibility

    Directory of Open Access Journals (Sweden)

    Menéndez, E.

    2013-12-01

    Full Text Available The disposal of coal by products represents environmental and economical problems around the world. Therefore, the reuse and valorisation of this waste has become an important issue in the last decades. While high-value construction products containing fly ash were developed and its use is actually totally accepted as an addition to cement, the use of the bottom ash as supplementary cementitious material has not been allow. This paper examines the chemical and physical properties of fly ashes and bottom ashes from two different coal power plants in order to compare them and analyse the potential feasibility of bottom ash as cement replacement. The mechanical properties of cement mortars made with different percentages of both ashes were also study. The results obtained showed similar chemical composition of both kinds of ashes. The compressive strength values of mortars with 10 % and 25 % of cement replacement (at 28 days were above the limits established in European standards and there were not significant differences between fly ash and bottom ash from both origins.La eliminación de subproductos del carbón supone problemas ambientales y económicos en todo el mundo por lo que la reutilización y valorización de los mismos se ha convertido en un tema importante en las últimas décadas. Mientras que las cenizas volantes se han utilizado en aplicaciones de alto valor y se han desarrollado productos de construcción en los que se ha utilizado esta ceniza como adición al cemento, no se ha sido permitido la utilización de la ceniza de fondo como en cementos. Este artículo examina las propiedades químicas y físicas de las cenizas volantes y de fondo procedentes de dos centrales termoeléctricas con el objetivo de compararlas y analizar la potencial utilización de la ceniza de fondo como adición al cemento. Se han estudiado también las propiedades mecánicas de morteros de cemento fabricados con distintos porcentajes de ambas cenizas como sustitución del cemento. Los resultados obtenidos mostraron que las ambos tipos de cenizas tenían una composición química similar. Los valores de resistencia a compresión a 28 días de los morteros con un 10 % y 25 % de porcentaje de sustitución estaban dentro de los límites permitidos en la normativa Europea y no había diferencias significativas entre las cenizas volantes y de fondo procedentes de ambas centrales térmicas.

  7. The Character of Dual Site Adsorbent on Coal Fly Ash Toward Benzene Adsorption

    Directory of Open Access Journals (Sweden)

    Widi Astuti

    2014-10-01

    Full Text Available Large quantities of coal fly ash (CFA are produced during combustion of coal in the production of electricity. Most of this ash has not been widely used. CFA is mainly composed of some oxides including Al2O3 and SiO2 having active site and unburnedcarbon as a mesopore that enables it to act as a dual site adsorbent. To get different characters of dual site, CFA was sieved using 150 mesh size, heated at 400oC and reactedwith sodium hydroxide solution. Furthermore, CFA was used as adsorbent of benzene in aqueous solutions. Equilibrium data were evaluated by single site and dual site isotherm models. It can be concluded that single site model yielded excellent fit with equilibrium data of benzene. The values of maximum concentration of adsorbate in solid surface (C?m and Langmuir constant (KL are affected by [Si+Al]/C ratio in CFA. The increase of [Si+Al]/C ratio causes a decrease of qm and KL values.Keywords : coal fly ash, adsorption, benzene

  8. Bibliographic review on organic compounds in coal ash; Etude bibliographique sur les composes organiques dans les cendres de charbon

    Energy Technology Data Exchange (ETDEWEB)

    Soreau, S.

    1996-12-31

    Production of ash by conventional fossil-fuel power plants is more closely watched by plant operators, due to the increase environmental regulatory constraints. A number of studies have been conducted in recent years to improve understanding of the physical and chemical characteristics of ash in relation to the fuels, equipment and operating conditions of the plants. The purpose of this study was to establish a bibliographical summary of the various families of organic compounds found in coal ash, and on their concentrations, their conditions of formation and adsorption on ash and their possible impact on the environment. In particular, we examined pollutants targeted by current regulations or regulations now being drawn up with respect to combustion installations. The study revealed the presence of a high number of organic compounds in coal ash. Many aliphatics, monocyclic aromatics and carbonyls are found, as well as heavier compounds which have become a matter of concern to scientists and public authorities in recent years because of their toxicity: polycyclic aromatic hydrocarbons (PAHs) and dioxins and furans (PCDDs and PCDFs). Their generally low concentrations can vary from a few pg/g to several dozen {mu}g/g. Among these compounds, dioxins and furans are found in the lowest concentrations, close to the thresholds of detection (pg/g). PAHs, most of which are non-carcinogenic, are normally found in concentrations from a few ng/g to a few hundred ng/g in the case of fly ash. These concentrations are often lower than those found in the ground and in fly ash from municipal incinerators. Furthermore coal bottom ash contains PAH concentrations which can exceed those found in coal fly ash by 2 orders of magnitude. It is difficult to analyze the environmental impact of such compounds, due to the lack of data on leaching. Most often, the authors agree that the risk that the organic compounds in coal ash will endanger the environmental are limited. (author) 58 refs.

  9. Radon exhalation of cementitious materials made with coal fly ash: Part 2 - testing hardened cement-fly ash pastes

    International Nuclear Information System (INIS)

    Increased interest in measuring radionuclides and radon concentrations in fly ash (FA), cement and other components of building products is due to the concern about health hazards of naturally occurring radioactive materials (NORM). The paper focuses on studying the influence of FA on radon exhalation rate (radon flux) from cementitious materials. In the previous part of the paper the state of the art was presented, and the experiments for testing raw materials, Portland cement and coal fly ash, were described. Since the cement and FA have the most critical role in the radon release process relative to other concrete constituents (sand and gravel), and their contribution is dominant in the overall radium content of concrete, tests were carried out on cement paste specimens with different FA contents, 0-60% by weight of the binder (cement+FA). It is found that the dosage of FA in cement paste has a limited influence on radon exhalation rate, if the hardened material is relatively dense. The radon flux of cement-FA pastes is lower than that of pure cement paste: it is about ?3 mBq m-2 s-1 for cement-FA pastes with FA content as high as 960 kg m-3

  10. Evaluation of the effects of coal fly ash amendments on the toxicity of a contaminated marine sediment

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, R.M.; Perron, M.M.; Friedman, C.L.; Suuberg, E.M.; Pennell, K.G.; Cantwell, M.G.; Pelletier, M.C.; Ho, K.T.; Serbst, J.R.; Ryba, S.A. [US EPA, Narragansett, RI (USA). Office for Research and Development

    2009-01-15

    Approaches for cleaning up contaminated sediments range from dredging to in situ treatment. In this study, we discuss the effects of amending reference and contaminated sediments with coal fly ash to reduce the bioavailability and toxicity of a field sediment contaminated with polycyclic aromatic hydrocarbons (PAHs). Six fly ashes and a coconut charcoal were evaluated in 7-d whole sediment toxicity tests with a marine amphipod (Ampelisca abdita) and mysid (Americamysis bahia). Fly ashes with high carbon content and the coconut charcoal showed proficiency at reducing toxicity. Some of the fly ashes demonstrated toxicity in the reference treatments. It is suspected that some of this toxicity is related to the presence of ammonia associated with fly ashes as a result of postoxidation treatment to reduce nitrous oxide emissions. Relatively simple methods exist to remove ammonia from fly ash before use, and fly ashes with low ammonia content are available. Fly ashes were also shown to effectively reduce overlying water concentrations of several PAHs. No evidence was seen of the release of the metals cadmium, copper, nickel, or lead from the fly ashes. A preliminary 28-d polychaete bioaccumulation study with one of the high-carbon fly ashes and a reference sediment was also performed. Although preliminary, no evidence was seen of adverse effects to worm growth or lipid content or of accumulation of PAHs or mercury from exposure to the fly ash. These data show fly ashes with high carbon content could represent viable remedial materials for reducing the bioavailability of organic contaminants in sediments.

  11. Ash transformation in suspension fired boilers co-firing coal and straw : Final report, PSO-Eltra 4766

    DEFF Research Database (Denmark)

    Zheng, Yuanjing; Jensen, Peter Arendt

    2009-01-01

    The properties of the ash from co-firing of coal and straw have a large influence on boiler operation, flue gas cleaning equipment and appropriate utilization of the fly ash. A study on the fuel composition and local conditions influence on fly ash properties has been done by making entrained flow reactor experiments with co-firing of coal and straw, making mineral and alkali vapor laboratory reactor experiments and by developing a model of KCl reaction with kaolin. The results include correlations that can be used to estimate the speciation of potassium in the fly ash when co-firing straw and bituminous coal. The laboratory experiments indicated which mineral types and local conditions that provide the most efficient binding of potassium to species with a high melting point, and where a simultaneous release of chlorine as gaseous HCl takes place.

  12. Deposit formation in a full-scale pulverized wood-fired power plant with and without coal fly ash addition

    DEFF Research Database (Denmark)

    Wu, Hao; Shafique Bashir, Muhammad

    2013-01-01

    Ash transformation and deposition in a pulverized wood-fired power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was investigated by using an advanced deposit probe system at two different boiler locations with flue gas temperatures of ~1300oC and ~800oC, respectively. It was found that during pulverized wood combustion, the deposit formation at the hightemperature location was characterized by a slow and continuous growth of deposits followed by the shedding of a large layer of deposits, while the deposit formation at the low-temperature location showed a slow initial build-up and a stable mass of deposits after approximately 1-5 h. The deposits collected during pulverized wood combustion contained a considerable amount of K2SO4, KCl, and KOH/K2CO3. With the addition of coal fly ash (~4 times of the mass flow of wood ash) to the boiler, these alkali species were effectively removed both in the fly ash and in the deposits, and a morefrequent shedding of the deposits was observed. The results imply that coal fly ash can be an effective additive to reduce ash deposition and corrosion problems in a pulverized wood-fired boiler.

  13. Removal of heavy metals from wastewater using functionalized coal fly ashes

    International Nuclear Information System (INIS)

    Complete text of publication follows. Among inorganic pollutants, heavy metal ions are very toxic and carcinogenic in nature. The presence of heavy metals in the aquatic environment has been of the greatest concern because of their toxicity even at very low concentrations. Therefore, the removal of the toxic metal ions prior to supplying water for drinking, bathing, etc is very important. Nonetheless, the removal of the toxic metal ions from water is a very difficult task due to the high cost of treatment methods. Adsorption is by far the most versatile and widely used method for this purpose. In this study, attempts have been made to develop a low-cost adsorbent using coal fly ashes, a waste byproduct of the coal fire industry, for the removal of arsenic, aluminium, cadmium, zinc, copper, iron, lead, manganese and nickel from wastewater. After applying a washing step to the coal fly ashes, functionalized fly ash surfaces were accomplished by using several organic compounds. The effect of several parameters (contact time, temperature, time that the ashes remain functionalized, concentration of the heavy metals, solution pH) on the adsorption process was stated. Several equilibrium and kinetics treatments were also carried out, also resulting that the adsorption process was found to be exothermic in nature. Retention studies were characterised by SEM/ED-XRS, FT-IR, Raman spectrometry and electrothermal atomic absorption spectrometry (ETAAS). The optimised retention system was applied to develop an analytical procedure for the retention of low concentrations of lead in wastewater and determination by ETAAS.

  14. Relationship between ash content and R{sub 70} self-heating rate of Callide Coal

    Energy Technology Data Exchange (ETDEWEB)

    Beamish, B. Basil; Blazak, Darren G. [School of Engineering, The University of Queensland, St Lucia, Qld 4072 (Australia)

    2005-10-17

    Borecore samples from the Trap Gully pit at Callide have been assessed using the R{sub 70} self-heating test. The highest R{sub 70} self-heating rate value was 16.22 {sup o}C/h, which is consistent with the subbituminous rank of the coal. R{sub 70} decreases significantly with increasing mineral matter content, as defined by the ash content of the coal. This effect is due to the mineral matter in the coal acting as a heat sink. A trendline equation has been fitted to the borecore data from the Trap Gully pit: R{sub 70}=0.0029xash{sup 2}-0.4889xash+20.644, where all parameters are on a dry-basis. This relationship can be used to model the self-heating hazard of the pit, both vertically and laterally. (author)

  15. Distributional Fate of Elements during the Synthesis of Zeolites from South African Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Pieter W. Du Plessis

    2014-04-01

    Full Text Available The synthesis of zeolites from South African coal fly ash has been deemed a viable solution to the growing economical strain caused by the disposal of ash in the country. Two synthesis routes have been studied thus far namely the 2-step method and the fusion assisted process. Fly ash contains several elements originating from coal which is incorporated in the ash during combustion. It is vital to determine the final destination of these elements in order to unveil optimization opportunities for scale-up purposes. The aim of this study was to perform a material balance study on both synthesis routes to determine the distributional fate of these elements during the synthesis of zeolites. Zeolites were first synthesized by means of the two synthesis routes. The composition of all raw materials and products were determined after which an overall and elemental balance were performed. Results indicated that in the 2-step method almost all elements were concentrated in the solid zeolite product while during the fusion assisted route the elements mostly report to the solid waste. Toxic elements such as Pb, Hg, Al, As and Nb were found in both the supernatant waste and washing water resulting from each synthesis route. It has also been seen that large quantities of Si and Al are wasted in the supernatant waste. It is highly recommended that the opportunity to recycle this liquid waste be investigated for scale-up purposes. Results also indicate that efficiency whereby Si and Al are extracted from fused ash is exceptionally poor and should be optimized.

  16. Investigation and measurement of ash content of coal in Zirab coal Mine-Iran using dual energy ?-ray and x-ray fluorescence methods

    International Nuclear Information System (INIS)

    Coal with low ash content has an important role in the coal and steel industry. There are different methods to measure the ash content. The conventional method which is used in most coal mines of Iran, is to burn the coal and measure the remaining ash. A new method has been recently developed at Nuclear Research Center of Iran, which works on the basis of the ob sorption of the dual energy ?-ray by coal. In this paper we present the results obtained from coal mine Zirab, Central Alborz, Iranto which we have applied this method, and compared the results with those obtained by the conventional method. In addition, the chemical components of the coal samples from six layers of this mine was obtained by X-ray fluorescence. We have found that for SiO2, Al2O3, TiO2, Na2O and K2O there exists a linear relationship between these components and the ash content, but such a relationship was not obtained for Fe2O3, Ca O, SO3 and Mg O

  17. Ash fouling monitoring and key variables analysis for coal fired power plant boiler

    Directory of Open Access Journals (Sweden)

    Shi Yuanhao

    2015-01-01

    Full Text Available Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process, artificial neural networks (ANN are used to optimize the boiler soot-blowing model and mean impact values method is utilized to determine a set of key variables. The validity of the models has been illustrated in a real case-study boiler, a 300MW Chinese power station. The results on same real plant data show that both models have good prediction accuracy, while the ANN model II has less input parameters. This work will be the basis of a future development in order to control and optimize the soot-blowing of the coal-fired power plant utility boilers.

  18. Characterization and catalytic activities of faujasites synthesized by using coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.; Oumi, Y.; Sano, T.; Yamana, K. [Industrial Technology Research Institute, Kanazawa (Japan). Chemical & Food Dept, Ceramic Section

    2001-11-01

    Coal combustion by-product fly ash was converted selectively into faujasite (Y type) zeolite and was used as a catalytic material. Fused fly ash powder and supernatant were used in the synthesis of Y type zeolite. The prepared Na-Y zeolites were characterized and ion-exchanged followed by calcination to obtain H-Y. The catalytic properties of the solid obtained were evaluated using cumene cracking and compared with those of commercially available (standard) zeolites. It was found that most of the Si and Al components in the fly ash could be effectively transformed into Y type zeolite in the presence of seeds but not the mineral phase, such as mullite. Moreover, the supernatant of the fused powder solution can produce purer faujasites and the sediment can be reused to generate solution for the further preparation of zeolites. Investigation by NMR demonstrated that fusion plays an important role in enhancing the hydrothermal conditions for zeolite synthesis. The H-Y zeolite derived from the supernatant of fly ash solution shows excellent cracking activity compared to that of standard.

  19. Growth responses of selected freshwater algae to trace elements and scrubber ash slurry generated by coal-fired power plants

    Energy Technology Data Exchange (ETDEWEB)

    Vocke, R.W.

    1979-01-01

    The development and implementation of standard toxicity tests is a necessity if consistent and reliable data are to be obtained for water quality criteria. The adapted EPA AAPBT is an ideal static algal toxicity test system. The algal test medium has a chemical composition similar to natural unpolluted waters of low ionic strength. It is appropriate to use MATC water quality criteria when assessing the potential impact of pollutants generated by coal-fired power stations because these energy-generated pollutants typically enter aquatic systems in small quantities over long periods. The MATC water quality criteria are estimates of trace element and SASE levels, based on the most sensitive alga investigated, that will not cause significant changes in naturally-functioning algal populations. These levels are 0.016f mg L/sup -1/ As(V), 0.001 mg L/sup -1/ Cd(II), 0.004 mg L/sup -1/ Hg(II), 0.006 mg L/sup -1/ Se(VI), and 0.344% SASE. To provide viable working water quality criteria, an extrapolation from the laboratory to the natural environment must be made. Therefore, those oxidation states of the trace elements were selected which are the dominant states occurring in natural, unpolluted, slightly alkaline freshwaters. It must be pointed out that these MATC values are based on algal responses to single toxicants and no allowance is made for synergistic, additive, or antagonistic relationships which could occur in natural aquatic systems. Additionally, natural chelation may influence toxicity. The highly toxic nature of potential pollutants from coal-fired generating plants emphasizes the need for minimizing stack effluent pollutants and retaining scrubber ash slurry for proper disposal in an effort to maintain trace elements in concentration ranges compatible with naturally-functioning ecosystems.

  20. Multivariate calibration in the radioisotope measurements of ash content in coal

    International Nuclear Information System (INIS)

    Multivariate calibration models developed for the radioisotope gauges designed for the measurement of the ash content in coal were investigated. The models were computed using the full spectra of the Am-241 ?-rays scattered back and forward from the coal sample, as well as the spectra of X-ray fluorescence with back scattered radiation of Pu-238 source. The spectra of scattered ?-rays were registered with the scintillation detector whereas for detection of X-rays the proportional counter was used. Calibration set contained 43 coal samples from four mines and the ash content ranged from 4 to 78%. The linear and non-linear partial least square (PLS) models were investigated and compared with multiple linear regression (MLR) models. It was found that the lowest value of root mean square error of cross validation was obtained for the non-linear PLS model in the case of the spectra of scattered ?-rays and for the linear PLS model with preliminary data processing in the case of the XRF spectra. (author)

  1. An urgent need for an EPA standard for disposal of coal ash

    International Nuclear Information System (INIS)

    EPA, the White House, and electric utilities are stalled in a struggle over a proposed new rule on coal ash disposal. Although this rule is long overdue, EPA now stands on the cusp of bringing forward a landmark decision that could benefit aquatic resources in the USA for decades to come and also set an important regulatory leadership example for the international community to follow. However, multi-million dollar wildlife losses are continuing to pile up as things stall in Washington. In this commentary I use a newly reported example, Wildlife Damage Case 23, to further illustrate serious flaws in the National Pollutant Discharge Elimination System that EPA's new rule can address. Case 23 provides additional impetus for EPA and the White House to move swiftly and decisively to end surface impoundment disposal of coal ash and the associated toxic impacts to wildlife. - Wildlife poisoning from coal combustion waste shows how regulatory policy is influenced by politics and industry rather than prudent decisions based on credible scientific investigation

  2. Investigation on the high-temperature flow behavior of biomass and coal blended ash.

    Science.gov (United States)

    Xu, Jie; Yu, Guangsuo; Liu, Xia; Zhao, Feng; Chen, Xueli; Wang, Fuchen

    2014-08-01

    The high-temperature flow behavior of biomass (straw) and coal blended ash was studied. The variation of viscosity and the temperature of critical viscosity with different straw content were investigated. It is found that the straw ash with high viscosity is unsuitable for directly gasification and the 20% straw content sample can effectively decrease the viscosity. The solid phase content and mineral matters variation calculated by FactSage demonstrate the change of viscosity. In addition, the network theory illustrates that the Si-O-Si bond decreases to improve the viscosity of 20% straw content sample. The variation of mineral matters in XRD analysis validates the change of viscosity. Furthermore, the temperature of critical viscosity and lowest operation temperature reach the minimum when the straw content is 20%. Hysteresis between heating and cooling process of the sample with 20% straw content is more obvious than that of the samples with 40% and 80% straw content. PMID:24951936

  3. Environmental impacts of the Tennessee Valley Authority Kingston coal ash spill. 1. Source apportionment using mercury stable isotopes.

    Science.gov (United States)

    Bartov, Gideon; Deonarine, Amrika; Johnson, Thomas M; Ruhl, Laura; Vengosh, Avner; Hsu-Kim, Heileen

    2013-02-19

    Mercury stable isotope abundances were used to trace transport of Hg-impacted river sediment near a coal ash spill at Harriman, Tennessee, USA. ?(202)Hg values for Kingston coal ash released into the Emory River in 2008 are significantly negative (-1.78 ± 0.35‰), whereas sediments of the Clinch River, into which the Emory River flows, are contaminated by an additional Hg source (potentially from the Y-12 complex near Oak Ridge, Tennessee) with near-zero values (-0.23 ± 0.16‰). Nominally uncontaminated Emory River sediments (12 miles upstream from the Emory-Clinch confluence) have intermediate values (-1.17 ± 0.13‰) and contain lower Hg concentrations. Emory River mile 10 sediments, possibly impacted by an old paper mill has ?(202)Hg values of -0.47 ± 0.04‰. A mixing model, using ?(202)Hg values and Hg concentrations, yielded estimates of the relative contributions of coal ash, Clinch River, and Emory River sediments for a suite of 71 sediment samples taken over a 30 month time period from 13 locations. Emory River samples, with two exceptions, are unaffected by Clinch River sediment, despite occasional upstream flow from the Clinch River. As expected, Clinch River sediment below its confluence with the Emory River are affected by Kingston coal ash; however, the relative contribution of the coal ash varies among sampling sites. PMID:23157719

  4. Environmental, physical and structural characterisation of geopolymer matrixes synthesised from coal (co-)combustion fly ashes.

    Science.gov (United States)

    Alvarez-Ayuso, E; Querol, X; Plana, F; Alastuey, A; Moreno, N; Izquierdo, M; Font, O; Moreno, T; Diez, S; Vázquez, E; Barra, M

    2008-06-15

    The synthesis of geopolymer matrixes from coal (co-)combustion fly ashes as the sole source of silica and alumina has been studied in order to assess both their capacity to immobilise the potentially toxic elements contained in these coal (co-)combustion by-products and their suitability to be used as cement replacements. The geopolymerisation process has been performed using (5, 8 and 12 M) NaOH solutions as activation media and different curing time (6-48 h) and temperature (40-80 degrees C) conditions. Synthesised geopolymers have been characterised with regard to their leaching behaviour, following the DIN 38414-S4 [DIN 38414-S4, Determination of leachability by water (S4), group S: sludge and sediments. German standard methods for the examination of water, waste water and sludge. Institut für Normung, Berlin, 1984] and NEN 7375 [NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials. Determination of leaching of inorganic components with the diffusion test. Netherlands Normalisation Institute, Delft, 2004] procedures, and to their structural stability by means of compressive strength measurements. In addition, geopolymer mineralogy, morphology and structure have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that synthesised geopolymer matrixes were only effective in the chemical immobilisation of a number of elements of environmental concern contained in fly ashes, reducing (especially for Ba), or maintaining their leachable contents after the geopolymerisation process, but not for those elements present as oxyanions. Physical entrapment does not seem either to contribute in an important way, in general, to the immobilisation of oxyanions. The structural stability of synthesised geopolymers was mainly dependent on the glass content of fly ashes, attaining at the optimal activation conditions (12 M NaOH, 48 h, 80 degrees C) compressive strength values about 60 MPa when the fly ash glass content was higher than 90%. PMID:18006153

  5. Environmental, physical and structural characterisation of geopolymer matrixes synthesised from coal (co-)combustion fly ashes

    International Nuclear Information System (INIS)

    The synthesis of geopolymer matrixes from coal (co-)combustion fly ashes as the sole source of silica and alumina has been studied in order to assess both their capacity to immobilise the potentially toxic elements contained in these coal (co-)combustion by-products and their suitability to be used as cement replacements. The geopolymerisation process has been performed using (5, 8 and 12 M) NaOH solutions as activation media and different curing time (6-48 h) and temperature (40-80 oC) conditions. Synthesised geopolymers have been characterised with regard to their leaching behaviour, following the DIN 38414-S4 [DIN 38414-S4, Determination of leachability by water (S4), group S: sludge and sediments. German standard methods for the examination of water, waste water and sludge. Institut fuer Normung, Berlin, 1984] and NEN 7375 [NEN 7375, Leaching characteristics of moulded or monolithic building and waste materials. Determination of leaching of inorganic components with the diffusion test. Netherlands Normalisation Institute, Delft, 2004] procedures, and to their structural stability by means of compressive strength measurements. In addition, geopolymer mineralogy, morphology and structure have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that synthesised geopolymer matrixes were only effective in the chemical immobilisation of a number of elements of environmental concern contained in fly ashes, reducing (especially for Ba), or maintaining their leachable contents after the geopolymerisation process, but not for those elements present as oxyanions. Physical entrapment does not seem either to contribute in an important way, in general, to the immobilisation of oxyanions. The structural stability of synthesised geopolymers was mainly dependent on the glass content of fly ashes, attaining at the optimal activation conditions (12 M NaOH, 48 h, 80 oC) compressive strength values about 60 MPa when the fly ash glass content was higher than 90%

  6. Health and environmental impacts of increased generation of coal ash and FGD sludges. Report to the Committee on Health and Ecological Effects of Increased Coal Utilization.

    Science.gov (United States)

    Santhanam, C J; Lunt, R R; Johnson, S L; Cooper, C B; Thayer, P S; Jones, J W

    1979-12-01

    This paper focuses on the incremental impacts of coal ash and flue gas desulfurization (FGD) wastes associated with increased coal usage by utilities and industry under the National Energy Plan (NEP). In the paper, 1985 and 2000 are the assessment points using the baseline data taken from the Annual Environmental Analysis Report (AEAR, September 1977). In each EPA region, the potential mix of disposal options has been broadly estimated and impacts assessed therefrom. In addition, future use of advanced combustion techniques has been taken into account. The quantities of coal ash and FGD wastes depend on ash and sulfur content of the coal, emission regulations, the types of ash collection and FGD systems, and operating conditions of the systems and boiler. The disposal of these wastes is (or will be) subject to Federal and State regulations. The one key legal framework concerning environmental impact on land is the Resource Conservation and Recovery Act (RCRA). RCRA and related Federal and State laws provide a sufficient statutory basis for preventing significant adverse health and environmental impacts from coal ash and FGD waste disposal. However, much of the development and implementation of specific regulations lie ahead. FGD wastes and coal ash and FGD wastes are currently disposed of exclusively on land. The most common land disposal methods are inpoundments (ponds) and landfills, although some mine disposal is also practiced. The potential environmental impacts of this disposal are dependent on the characteristics of the disposal site, characteristics of the coal ash and FGD wastes, control method and the degree of control employed. In general, the major potential impacts are ground and surface water contamination and the "degradation" of large quantities of land. However, assuming land is available for disposal of these wastes, control technology exists for environmentally sound disposal. Because of existing increases in coal use, the possibility of significant environmental impacts, both regionally and nationally, exists regardless of whether the NEP scenario develops or not. Existing baseline data indicate that with sound control technology and successful development and implementation of existing regulatory framework, regional scale impacts are likely to be small; however, site-specific impacts could be significant and need to be evaluated on a case-by-case basis. Both Federal and privately-funded programs are developing additional data and information on disposal of FGD sludges and coal ash. Continuation of these programs will provide additional vital information in the future. However, further information in several areas if desirable: further data on levels of radionuclides and trace metals in these wastes: studies on biological impacts of trace metals; and completion of current and planned studies on disposal problems associated with advanced combustion techniques like fluid bed combustion. PMID:540614

  7. Radiological characterization of the coal ash and slag from Kastel Gomilica, Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Lovrencic, I.; Orescanin, V.; Barisic, D.; Mikelic, L.; Rozmaric Macefat, M.; Lulic, St. [Rudjer Boskovic Institute, Zagreb (Croatia); Pavlovic, G. [Zagreb Univ., Faculty of Science, Dept. of Mineralogy and Petrography (Croatia)

    2006-07-01

    objective of this study was radiological characterization of slag and ash produced in a thermo electric unit of the former 'Adriavinil' chemical factory as a by-product of coal combustion and deposited in the Kastel Gomilica region, Croatia. The waste material was deposited in the 'old' regulated and the 'new' unregulated part of the depot. 33 samples were analyzed to obtain a preliminary data on the present state of the new unregulated part of the depot. Activities of the selected radionuclides (40 K, 232 Th, 235 U and 226 Ra) were measured using gamma-spectrometry method. 238 U activity was calculated from the assumed natural 235 U /238 U activity ratio. It is found that there is a dependence of the activities of the selected radionuclides on the activities of the coal used for energy production in the power unit. The content of 232 Th, 226 Ra and 238 U in slag and ash increased several times during the combustion process. Investigated slag and ash showed a significant variability in their activities of selected radionuclides due to a different origin of coal used in the thermoelectric unit of the factory. The waste material was characterized by high activity of naturally occurring 238 U, 235 U and 226 Ra. 226 Ra and 238 U activities were up to 50 times higher than their average activities characteristic for surrounding soils developed on flysch sediments. 40 K and 232 Th showed no elevation compared to soil activities. Mineralogical analysis has been made as well. (authors)

  8. Characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption

    Science.gov (United States)

    Lu, Y.; Rostam-Abadi, M.; Chang, R.; Richardson, C.; Paradis, J.

    2007-01-01

    Nine fly ash samples were collected from the particulate collection devices (baghouse or electrostatic precipitator) of four full-scale pulverized coal (PC) utility boilers burning eastern bituminous coals (EB-PC ashes) and three cyclone utility boilers burning either Powder River Basin (PRB) coals or PRB blends,(PRB-CYC ashes). As-received fly ash samples were mechanically sieved to obtain six size fractions. Unburned carbon (UBC) content, mercury content, and Brunauer-Emmett-Teller (BET)-N2 surface areas of as-received fly ashes and their size fractions were measured. In addition, UBC particles were examined by scanning electron microscopy, high-resolution transmission microscopy, and thermogravimetry to obtain information on their surface morphology, structure, and oxidation reactivity. It was found that the UBC particles contained amorphous carbon, ribbon-shaped graphitic carbon, and highly ordered graphite structures. The mercury contents of the UBCs (Hg/UBC, in ppm) in raw ash samples were comparable to those of the UBC-enriched samples, indicating that mercury was mainly adsorbed on the UBC in fly ash. The UBC content decreased with a decreasing particle size range for all nine ashes. There was no correlation between the mercury and UBC contents of different size fractions of as-received ashes. The mercury content of the UBCs in each size fraction, however, generally increased with a decreasing particle size for the nine ashes. The mercury contents and surface areas of the UBCs in the PRB-CYC ashes were about 8 and 3 times higher than UBCs in the EB-PC ashes, respectively. It appeared that both the particle size and surface area of UBC could contribute to mercury capture. The particle size of the UBC in PRB-CYC ash and thus the external mass transfer was found to be the major factor impacting the mercury adsorption. Both the particle size and surface reactivity of the UBC in EB-PC ash, which generally had a lower carbon oxidation reactivity than the PRB-PC ashes, appeared to be important for the mercury adsorption. ?? 2007 American Chemical Society.

  9. Sequential leaching behaviour of some elements during chemical treatment of ceramic censorship from coal fly ash

    International Nuclear Information System (INIS)

    The extractable contents of Ca, Cr, Cu, Fe, Mg, Mn, Ni, Pb, and Zn were determined using a six-stage sequential leaching procedure to isolate: (1) water-soluble; (2) slightly changed organic matter; (3) carbonate; (4) Fe-Mn oxides; (5) glass and silicates; and (6) char fractions; of ceramic cenospheres (CCs) recovered from coal fly ash (FA). The leaching behaviour and modes of occurrence of the above-listed elements in CCs are discussed. The results show that this improved sequential leaching procedure applied on well characterized chemically and mineralogically CCs is promising and could be successfully used. (authors)

  10. Use of coal ash for enhancing biocrust development in stabilizing sand dunes

    Science.gov (United States)

    Zaady, Eli; Katra, Itzhak; Sarig, Shlomo

    2015-04-01

    In dryland environments, biocrusts are considered ecosystem engineers since they play significant roles in ecosystem processes. In the successional pathway of crust communities, the new areas are colonized after disturbance by pioneers such as filamentous cyanobacteria - Microcoleus spp. This stage is followed by colonization of green algae, mosses, and lichens. Aggregation of soil granules is caused by metabolic polysaccharides secreted by cyanobacteria and green algae, gluing the soil particles to form the crust layer. It was suggested that incorporating dust into the biocrusts encourages the growth of cyanobacteria, leading to a strengthening of the biocrusts' cohesion. Moreover, biocrusts cover a larger portion of the surface when the soil contains finer particles, and it was observed that at least 4-5% of clay and silt is required to support a measurable biocrust. While natural and undisturbed sand dunes are generally stabilized by biocrusts in the north-western Negev desert, stabilization of disturbed and movable sand dunes is one of the main problems in this desertified land, as in vast areas in the world. Daily breezes and seasonal wind storms transport sand particles to populated and agricultural areas causing damages to field crops and livelihood. Moving sand dunes consist of relatively coarse grains (250-2000 ?m) with a low percent of clay and silt. This phenomenon negatively affects cyanobacterial colonization rate, even in relatively wet desert areas (100-250 mm rainfalls). In order to face the problem it was suggested to enrich the dune surface by using coal fly-ash. The research was conducted in two stages: first, examining the feasibility in Petri-dishes in laboratory conditions and in Experimental Aeolian Greenhouse conditions. The results showed that adding coal fly-ash and biocrust inoculum increased aggregate stability, penetration resistance and shear strength, as opposed to the control-sand plot. Using mobile wind-tunnel simulations, sand fluxes in the experimental plots under different wind speeds (5 to 9 m s-2) showed significant differences in favor of the treatment of coal fly-ash + biocrusts inoculum, compared to the controls (sand, sand + biocrusts and sand + coal fly-ash).

  11. Mineral sequestration of CO2 by aqueous carbonation of coal combustion fly-ash

    OpenAIRE

    Montes-Hernandez, G.; Perez-Lopez, R.; Renard, F.; Nieto, J.-M.; Charlet, L.

    2008-01-01

    The increasing CO2 concentration in the Earth's atmosphere, mainly caused by fossil fuel combustion, has led to concerns about global warming. A technology that could possibly contribute to reducing carbon dioxide emissions is the in-situ mineral sequestration (long term geological storage) or the ex-situ mineral sequestration (controlled industrial reactors) of CO2. In the present study, we propose to use coal combustion fly-ash, an industrial waste that contains about 4.1 wt.% of lime (CaO)...

  12. Study of Remediation of Soil Contamined with Heavy Metals by Coal Fly Ash

    OpenAIRE

    Jan Kalembkiewicz; El?bieta Sitarz-Palczak

    2012-01-01

    The labile fraction of heavy metals in soils is the most important for toxicity for plants. Thus it is crucial to reduce this fraction in contamined soils to decrease the negative effect of heavy metals. In an experiment, the effects of two additives on the labile fractions of Cu, Mn and Zn were investigated in a soil contamined during long-term application. The additive used was the coal fly ash. The treated soil was further enriched with heavy metals and allowed to age at room temperature f...

  13. Presumption of use for fly ash in alkali activation

    International Nuclear Information System (INIS)

    In recent years, increasingly comes fly ash from energy industry into the forefront of many research institutes. This is due mainly by effort to take advantage of a huge quantity of fly ash and transform it into a promising material that could replace the natural resources. One of the newest areas dealing with the use of fly ash is alkaline activation, which can bring a whole new perspective on this material and its use. Due to mineralogical composition of coal can be used residues of aluminosilicate, which are contained in fly ash. An important factor is the nature of the present crystalline aluminosilicates, which is determined by the parameters of the combustion process and largely decides the reactivity of fly ash. Therefore, in this article will be described the main prerequisites for the utilization of fly ash in alkaline alkalinisation, and these assumptions will be confronted with a sample of fly ash utilized for alkali activation. (Authors)

  14. Evaluation of radioactivity levels of coal, slag and fly ash samples used in Giresun province of Turkey

    International Nuclear Information System (INIS)

    In present work natural radionuclides activities (236Ra, 232Th and 40K) of the different types of coal, slag and fly ash samples used in Giresun province (Eastern Black Sea region of Turkey) were measured by using gamma-ray spectrometry. These samples were collected as homogeneously and separately around Giresun province. The mean activity concentrations of 226Ra, 232Th and 40K radionuclides in coal, slag and fly ash samples were found as 107, 67 and 440 Bg.Kg-1 for coal; 59, 25 and 268 Bg.kg-1 for slag and 136, 60 and 417 Bg.kg-1 for fly ash samples, respectively. To estimate health effect due to the aforementioned radionuclides, absorbed dose rates and annual effective doses have been calculated. These values were evaluated and compared with the internationally recommended values

  15. Measurement of radon activity, exhalation rate and radiation dose in fly ash and coal samples from NTPC, Badarpur, Delhi, India

    International Nuclear Information System (INIS)

    In the present study radon activities and exhalation rates from fly ash and coal samples from NTPC (National Thermal Power Corporation) situated at Badarpur, Delhi, India, have been measured. 'Sealed Can Technique' using LR-115 type II track detectors was employed. In fly ash samples, radon activity has been found to vary from 400.0 ± 34.7 to 483.9 ± 38.1Bqm-3 with an average value of 447.1 ± 36.6 Bqm-3 and in coal samples, radon activity has been found to vary from 504.0 ± 39.0 to 932.1 ± 52.9 Bqm-3 with an average value of 687.2 ± 45.2 Bqm-3. Radon exhalation rate from coal is found to be higher than radon exhalation rate from its ash products, whereas the opposite is expected. Indoor inhalation exposure (radon) effective dose has also been estimated. (author)

  16. Coal fly ash effluent affects the distributions of Brachionus calyciflorus sibling species.

    Science.gov (United States)

    Zhang, Gen; Xi, Yi-Long; Xue, Ying-Hao; Xiang, Xian-Ling; Wen, Xin-Li

    2015-02-01

    Fly ash, a coal combustion residue of thermal power plants and a source of multiple pollutants, has been recognized as an environmental hazard all over the world. Although it is known that fly ash effluent affects density, diversity and distribution of rotifers in drainage systems and receiving water bodies, the effect of fly ash effluent on the distributions of highly similar rotifer species remains unknown. In this study, the mtDNA COI genes of 90 individuals in Brachionus calyciflorus complex from Lake Hui (as a fly ash discharge water pond) and other two neighboring lakes (Lake Fengming and Lake Tingtang) were sequenced and analyzed, and the responses in selected life table demographic parameters (life expectancy at hatching, net reproductive rate, intrinsic rate of population increase and proportion of sexual offspring) of different rotifer populations to fly ash effluent were investigated. Overall, 72 mtDNA haplotypes were defined, and were split into two clades by the phylogenetic trees. The divergence of COI gene sequences between the two clades ranged from 11.8% to17.8%, indicating the occurrence of two sibling species (sibling species I and sibling species II). Sibling species I distributed in all the three lakes, showing strong capabilities for dispersal and colonization, which were supported by its higher level of gene flow (2.60-4.04) between the populations from Lake Hui and each of the other two lakes, longer life expectancy at hatching (101.6-148.2 h), and higher net reproductive rate (4.4-16.4 offspring/female) and intrinsic rate of population increase (0.60-0.98/d) when cultured in aerated tap water and fly ash effluent. Sibling species II distributed in both Lake Tingtang and Lake Fengming, showing that its dispersal existed between the two lakes. Considering that the distance between Lake Hui and Lake Fengming is shorter than that between Lake Tingtang and Lake Fengming, sibling species II is able to disperse at least from Lake Fengming to Lake Hui. The restricted distribution of sibling species II in Lake Hui might be attributed to its lower intrinsic rate of population increase (0.34-0.39/d) when cultured in aerated tap water and fiy ash effluent, which might be further lowered by the lower algal food level and quality in Lake Hui. PMID:25463854

  17. Development of a modeling approach to predict ash formation during co-firing of coal and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Doshi, V. [School of Engineering, Monash University Sunway Campus, Jalan Lagoon Selatan, Bandar Sunway, Selangor (Malaysia); Vuthaluru, H.B. [Curtin University of Technology, Kent Street, Bentley 6104, Perth, Western Australia (Australia); Korbee, R. [HRL Technology, Ipswich, Queensland (Australia); Kiel, J.H.A. [ECN Biomass, Coal and Environmental Research, P.O. Box 1, 1755 ZG Petten (Netherlands)

    2009-09-15

    The scope of this paper includes the development of a modelling approach to predict the ash release behaviour and chemical composition of inorganics during co-firing of coal and biomass. In the present work, an advanced analytical method was developed and introduced to determine the speciation of biomass using pH extraction analysis. Biomass samples considered for the study include wood chips, wood bark and straw. The speciation data was used as an input to the chemical speciation model to predict the behaviour and release of ash. It was found that the main gaseous species formed during the combustion of biomass are KCl, NaCl, K{sub 2}SO{sub 4} and Na{sub 2}SO{sub 4}. Calculations of gas-to-particle formation were also carried out to determine the chemical composition of coal and biomass during cooling which takes place in the boiler. It was found that the heterogeneous condensation occurring on heat exchange surfaces of boilers is much more than homogeneous condensation. Preliminary studies of interaction between coal and biomass during ash formation process showed that Al, Si and S elements in coal may have a 'buffering' effect on biomass alkali metals, thus reducing the release of alkali-gases which act as precursors to ash deposition and corrosion during co-firing. The results obtained in this work are considered to be valuable and form the basis for accurately determining the ash deposition during co-firing. (author)

  18. The influence of coal bottom ash and tincal (boron mineral) additions on the physical and microstructures of ceramic bodies

    Energy Technology Data Exchange (ETDEWEB)

    Bayca, S.U.; Batar, T.; Sayin, E.; Solak, O.; Kahraman, B. [Celal Bayar University, Manisa (Turkey). Soma Vocational School

    2008-07-01

    In this paper, the influence of coal bottom ash and tincal additions on the physical properties and microstructures of the standard wall tile body composition was investigated. Water absorption, fang strength, dry and fired shrinkage tests of the incorporated ceramic bodies and reference body were done. Microstructures of sintered tiles were analyzed using a scanning electron microscope (SEM). The results show that tincal additions to the ceramic body improved the physical properties of the tiles. As a result, tincal can be used as a flux material in the ceramic bodies due to its favorable effects on the water absorption and fired strength. The results revealed that bottom ash can be used in the ceramic tile body composition. When bottom ash was used in the ceramic industry, environmental hazards of bottom ash are inhibited. Furthermore, bottom ash is transformed to an economic product.

  19. Deposit formation in a full-scale pulverized wood-fired power plant with and without coal fly ash addition

    DEFF Research Database (Denmark)

    Wu, Hao; Shafique Bashir, Muhammad; Jensen, Peter Arendt; Sander, Bo; Glarborg, Peter

    2013-01-01

    Ash transformation and deposition in a pulverized wood-fired power plant boiler of 800 MWth were studied with and without the addition of coal fly ash. The transient ash deposition behavior was investigated by using an advanced deposit probe system at two different boiler locations with flue gas temperatures of ~1300oC and ~800oC, respectively. It was found that during pulverized wood combustion, the deposit formation at the hightemperature location was characterized by a slow and continuous gro...

  20. Method for increasing -SiC yield on solid state reaction of coal fly ash and activated carbon powder

    Indian Academy of Sciences (India)

    Sulardjaka; Jamasri; M W Wildan; Kusnanto

    2011-07-01

    A novel process for increasing -SiC yield on solid state reaction of coal fly ash and micro powder activated carbon powder has been proposed. -SiC powder was synthesized at temperature 1300°C for 2 h under vacuum condition with 1 l/min argon flow. Cycling synthesis process has been developed for increasing -SiC yield on solid state reaction of coal fly ash and activated carbon powder. Synthesized products were analyzed by XRD with Cu-K radiation, FTIR spectrometer and SEM fitted with EDAX. The results show that the amount of relative -SiC is increased with the number of cycling synthesis.

  1. Use of the flying ashes of the coal in the synthesis of zeolitic material with interchange properties of ammonium ion

    International Nuclear Information System (INIS)

    In this research W and F zeolites are synthesized from analytical reagents and from coal fly ash as a source of aluminum and silicon. The primary goal with the synthesis of these materials is to show the possibility of their economic production and their potential application in ammonium removal from aquaculture water and wastewater. The results show that zeolites W and F can be obtained readily from the coal fly ashes almost with the same synthesis parameters as when pure analytical reagents are used for the same purpose. Their ammonium ion exchange capacity indicates that zeolites from both types of sources, behave similarly

  2. Adsorptive removal of various phenols from water by South African coal fly ash

    Scientific Electronic Library Online (English)

    JH, Potgieter; SO, Bada; SS, Potgieter-Vermaak.

    2009-01-01

    Full Text Available South African coal fly ash (SACFA) was used to effectively remove phenol, 2-nitrophenol and 4-nitrophenol from wastewater. The rate of adsorption follows first-order kinetics before attaining equilibrium with the sorption rate (Kad) obtained being the highest for 4-nitrophenol (p-nitrophenol) (7.0 x [...] 10³/h), followed by phenol (1.2 x 10³/h) and 2-nitrophenol (o-nitrophenol) (1.0 x 10³/h). Batch studies were performed to evaluate the adsorption process, and it was found that the Freundlich isotherm effectively fits the experimental data for the adsorbates better than the Langmuir model, with the fly ash having the highest adsorption capacity of 6.51 X 10-2 mg/g for 4-nitrophenol, 6.00 x 10-2 mg/g for 2-nitrophenol and 6.31 x10-2 mg/g for phenol. The fly ash was found to adsorb 90.2% of phenol, 88.9% of 2-nitrophenol and 92.6% of 4-nitrophenol at an initial concentration of 20 mg/?. The desorption studies suggested that the desorption of 4-nitrophenol was the most difficult of the three adsorbates to be desorbed. The desorption efficiency was 17.9% for phenol, 18.8% for 2-nitrophenol and 10.2% for 4-nitrophenol. This work proved that SACFA can be used as an efficient adsorbent material for removal of phenol from water and wastewater.

  3. Flue gas desulfurization gypsum and coal fly ash as basic components of prefabricated building materials.

    Science.gov (United States)

    Telesca, Antonio; Marroccoli, Milena; Calabrese, Daniela; Valenti, Gian Lorenzo; Montagnaro, Fabio

    2013-03-01

    The manufacture of prefabricated building materials containing binding products such as ettringite (6CaO·Al2O3·3SO3·32H2O) and calcium silicate hydrate (CSH) can give, in addition to other well-defined industrial activities, the opportunity of using wastes and by-products as raw materials, thus contributing to further saving of natural resources and protection of the environment. Two ternary mixtures, composed by 40% flue gas desulfurization (FGD) gypsum or natural gypsum (as a reference material), 35% calcium hydroxide and 25% coal fly ash, were submitted to laboratory hydrothermal treatments carried out within time and temperature ranges of 2h-7days and 55-85°C, respectively. The formation of (i) ettringite, by hydration of calcium sulfate given by FGD or natural gypsum, alumina of fly ash and part of calcium hydroxide, and (ii) CSH, by hydration of silica contained in fly ash and residual lime, was observed within both the reacting systems. For the FGD gypsum-based mixture, the conversion toward ettringite and CSH was highest at 70°C and increased with curing time. Some discrepancies in the hydration behavior between the mixtures were ascribed to differences in mineralogical composition between natural and FGD gypsum. PMID:23219474

  4. Alkaline hydrothermal zeolites synthesized from high SiO{sub 2} and Al{sub 2}O{sub 3} co-disposal fly ash filtrates

    Energy Technology Data Exchange (ETDEWEB)

    Vernon S. Somerset; Leslie F. Petrik; Richard A. White; Michael J. Klink; David Key; Emmanuel I. Iwuoha

    2005-12-01

    A co-disposal reaction was used wherein fly ash (FA) was reacted with acid mine drainage (AMD), to collect filtrates for zeolite synthesis. Raw fly ash as well as fly ash leached with HCl were subjected to the same alkaline hydrothermal zeolite synthesis conditions, as for the co-disposal filtrates, in order to evaluate the zeolitic material obtained. The Si and Al contents of the fly ash (FA) filtrates were used as precursor species for the alkaline hydrothermal conversion of the fly ash filtrates into zeolites. These filtrates were then analysed by XRF spectrometry for quantitative determination of SiO{sub 2} and Al{sub 2}O{sub 3}. The (SiO{sub 2})/(Al{sub 2}O{sub 3}) ratio obtained in the filtrates range from 1.4 to 2.5. The (SiO{sub 2})/(Al{sub 2}O{sub 3}) ratio was used to predict whether the fly ash filtrates could successfully be converted into faujasite zeolitic material by the adopted synthesis procedures. If the (SiO{sub 2})/(Al{sub 2}O{sub 3}) ratio is higher than 1.5 in the co-disposal filtrates, it favours the formation of faujasite. The zeolite synthesis included an alkaline fusion of the co-disposal filtrates, followed by aging for 8 hours and hydrothermal conversion by crystallisation at 100{sup o}C. Different variables were investigated during the synthesis of zeolite to ascertain their influence on the end product. These variables include adding different amounts of deionised water to the FA-related starting material, using different compositions of FA related starting material and different FA:NaOH ratios in fusing the starting material. 15 refs., 3 figs., 2 tabs.

  5. Biosynthesis of titanium dioxide nanoparticles using a probiotic from coal fly ash effluent

    Energy Technology Data Exchange (ETDEWEB)

    Babitha, S; Korrapati, Purna Sai, E-mail: purnasaik.clri@gmail.com

    2013-11-15

    Graphical abstract: - Highlights: • Metal resistant probiotic species was isolated from coal fly ash effluent site. • Uniform sized anatase form of TiO{sub 2} nanoparticles were synthesized using Propionibacterium jensenii. • Diffraction patterns confirmed the anatase – TiO{sub 2} NPs with average size <80 nm. • TiO{sub 2} nanoparticle incorporated wound dressing exhibits better wound healing. - Abstract: The synthesis of titanium dioxide nanoparticle (TiO{sub 2} NP) has gained importance in the recent years owing to its wide range of potential biological applications. The present study demonstrates the synthesis of TiO{sub 2} NPs by a metal resistant bacterium isolated from the coal fly ash effluent. This bacterial strain was identified on the basis of morphology and 16s rDNA gene sequence [KC545833]. The physico-chemical characterization of the synthesized nanoparticles is completely elucidated by energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM, SEM). The crystalline nature of the nanoparticles was confirmed by X-RD pattern. Further, cell viability and haemolytic assays confirmed the biocompatible and non toxic nature of the NPs. The TiO{sub 2} NPs was found to enhance the collagen stabilization and thereby enabling the preparation of collagen based biological wound dressing. The paper essentially provides scope for an easy bioprocess for the synthesis of TiO{sub 2} NPs from the metal oxide enriched effluent sample for future biological applications.

  6. Recycling of Coal Fly Ash for the Fabrication of Porous Mullite/Alumina Composites

    Directory of Open Access Journals (Sweden)

    Kyu H. Kim

    2014-08-01

    Full Text Available Coal fly ash with the addition of Al2O3 was recycled to produce mullite/alumina composites and the camphene-based freeze casting technique was processed to develop a controlled porous structure with improved mechanical strength. Many rod-shaped mullite crystals, formed by the mullitization of coal fly ash in the presence of enough silicate, melt. After sintering at 1300–1500 °C with the initial solid loadings of 30–50 wt.%, interconnected macro-sized pore channels with nearly circular-shaped cross-sections developed along the macroscopic solidification direction of camphene solvent used in freeze casting and a few micron-sized pores formed in the walls of the pore channels. The macro-pore size of the mullite/alumina composites was in the range 20–25 ?m, 18–20 ?m and 15–17 ?m with reverse dependence on the sintering temperature at 30, 40 and 50 wt.% solid loading, respectively. By increasing initial solid loading and the sintering temperature, the sintered porosity was reduced from 79.8% to 31.2%, resulting in an increase in the compressive strength from 8.2 to 80.4 MPa.

  7. New fertilizer utilizing coal ash. ; Extragreen chemical fertilizer. Sekitanbai wo riyoshita shinhiryo. ; Extra green kasei hiryo

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This paper describes the results of culturing tests on different kinds of vegetables using the Extragreen fertilizer (a new fertilizer) that utilizes coal ash. The new fertilizer consists of aqueous phosphoric acid solution mixed uniformly with such fertilizer materials as nitrogen, phosphoric acid and potassium, and then mixed with coal ash so that it solidifies naturally. As a result of comparative discussions with fertilizers having been used by farmers, the use of the new fertilizer resulted in yield increase by 10% to several ten percent in cabbage, white radish, taro, and Chinese yam, and several percent to 10% in Chinese cabbage and paddy rice. With regard to quality, leaf vegetables such as cabbage had slow fresh weight reduction rate after harvest, with long lasting freshness. Root vegetables such as white radish, potato, Chinese yam, and sweet potato had their sweetness increased and their colors retained fresher, raising their commercial value. The present fertilizer showed a trend of reducing such continuous cropping injuries (soil diseases) as the root-knot disease in cabbage, the powder scab in potato, and the brown rots and root rots in Chinese yam. 5 figs.

  8. Effect of ultrasound energy on the zeolitization of chemical extracts from fused coal fly ash.

    Science.gov (United States)

    Bukhari, Syed Salman; Rohani, Sohrab; Kazemian, Hossein

    2016-01-01

    This paper investigates the effects of ultrasound (UTS) energy at different temperatures on the zeolitization of aluminosilicate constituents of coal fly ash. UTS energy irradiated directly into the reaction mixture utilizing a probe immersed into the reaction mixture, unlike previously reported works that have used UTS baths. Controlled synthesis was also conducted at constant stirring and at the same temperatures using conventional heating. The precursor reaction solution was obtained by first fusing the coal fly ash with sodium hydroxide at 550°C followed by dissolution in water and filtration. The synthesized samples were characterized by XRF, XRD, SEM and TGA. The crystallinity of crystals produced with UTS assisted conversion compared to conventional conversion at 85°C was twice as high. UTS energy also reduced the induction time from 60min to 40min and from 80min to 60min for reaction temperatures of 95°C and 85°C, respectively. Prolonging the UTS irradiation at 95°C resulted in the conversion of zeolite-A crystals to hydroxysodalite, which is a more stable zeolitic phase. It was found that at 85°C coupled with ultrasound energy produced the best crystalline structure with a pure single phase of zeolite-A. It has been shown that crystallization using UTS energy can produce zeolitic crystals at lower temperatures and within 1h, dramatically cutting the synthesis time of zeolite. PMID:26384882

  9. Determining the effects of waste coal ash on landfill radon levels. Master`s thesis

    Energy Technology Data Exchange (ETDEWEB)

    Krysiak, R.S.

    1995-12-01

    Coal contains trace amounts of the primary radionuclides K-40, and elements of the 4n (Th-232), 4n+2 (U-238), and 4n+3 (U-235) series, including Rn-220 and Rn-222. The purpose of this research was to determine the effects of landfilled coal ash on one specific aspect of technologically enhanced natural radiation, radon levels. Soil samples were collected from the ash landfill at Wright Patterson AFB and from several background locations, analyzed using gamma spectroscopy, and the Ra-226 activities compared. The landfill Ra-226 activity (4.78 + or - 1.58 pCi/g) was 2.95 times higher than background (1.62 + or - 0.04 pCi/g). Estimated outdoor and indoor radon emanation at the landfill are predicted to be enhanced by the same factor compared to background. Additionally, the indoor radon concentration calculated in a hypothetical structure built on the landfill (11.48 pCi/l) was above the Environmental Protection Agency`s action level of 4.0 pCi/l.

  10. Biosynthesis of titanium dioxide nanoparticles using a probiotic from coal fly ash effluent

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Metal resistant probiotic species was isolated from coal fly ash effluent site. • Uniform sized anatase form of TiO2 nanoparticles were synthesized using Propionibacterium jensenii. • Diffraction patterns confirmed the anatase – TiO2 NPs with average size 2 nanoparticle incorporated wound dressing exhibits better wound healing. - Abstract: The synthesis of titanium dioxide nanoparticle (TiO2 NP) has gained importance in the recent years owing to its wide range of potential biological applications. The present study demonstrates the synthesis of TiO2 NPs by a metal resistant bacterium isolated from the coal fly ash effluent. This bacterial strain was identified on the basis of morphology and 16s rDNA gene sequence [KC545833]. The physico-chemical characterization of the synthesized nanoparticles is completely elucidated by energy dispersive X-ray analysis (EDAX), Fourier transform infrared spectroscopy (FTIR) and transmission and scanning electron microscopy (TEM, SEM). The crystalline nature of the nanoparticles was confirmed by X-RD pattern. Further, cell viability and haemolytic assays confirmed the biocompatible and non toxic nature of the NPs. The TiO2 NPs was found to enhance the collagen stabilization and thereby enabling the preparation of collagen based biological wound dressing. The paper essentially provides scope for an easy bioprocess for the synthesis of TiO2 NPs from the metal oxide enriched effluent sample for future biological applications

  11. Elaboration of new ceramic microfiltration membranes from mineral coal fly ash applied to waste water treatment.

    Science.gov (United States)

    Jedidi, Ilyes; Saïdi, Sami; Khemakhem, Sabeur; Larbot, André; Elloumi-Ammar, Najwa; Fourati, Amine; Charfi, Aboulhassan; Salah, Abdelhamid Ben; Amar, Raja Ben

    2009-12-15

    This work aims to develop a new mineral porous tubular membrane based on mineral coal fly ash. Finely ground mineral coal powder was calcinated at 700 degrees C for about 3 h. The elaboration of the mesoporous layer was performed by the slip-casting method using a suspension made of the mixture of fly-ash powder, water and polyvinyl alcohol (PVA). The obtained membrane was submitted to a thermal treatment which consists in drying at room temperature for 24 h then a sintering at 800 degrees C. SEM photographs indicated that the membrane surface was homogeneous and did not present any macrodefects (cracks, etc...). The average pore diameter of the active layer was 0.25 microm and the thickness was around 20 microm. The membrane permeability was 475 l/h m(2) bar. This membrane was applied to the treatment of the dying effluents generated by the washing baths in the textile industry. The performances in term of permeate flux and efficiency were determined and compared to those obtained using a commercial alumina microfiltration membrane. Almost the same stabilised permeate flux was obtained (about 100 l h(-1)m(-2)). The quality of permeate was almost the same with the two membranes: the COD and color removal was 75% and 90% respectively. PMID:19699033

  12. The chemical composition of tertiary Indian coal ash and its combustion behaviour – a statistical approach: Part 2

    Indian Academy of Sciences (India)

    Arpita Sharma; Ananya Saikia; Puja Khare; D K Dutta; B P Baruah

    2014-08-01

    In Part 1 of the present investigation, 37 representative Eocene coal samples of Meghalaya, India were analyzed and their physico-chemical characteristics and the major oxides and minerals present in ash samples were studied for assessing the genesis of these coals. Various statistical tools were also applied to study their genesis. The datasets from Part 1 used in this investigation (Part 2) show the contribution of major oxides towards ash fusion temperatures (AFTs). The regression analysis of high temperature ash (HTA) composition and initial deformation temperature (IDT) show a definite increasing or decreasing trend, which has been used to determine the predictive indices for slagging, fouling, and abrasion propensities during combustion practices. The increase or decrease of IDT is influenced by the increase of Fe2O3, Al2O3, SiO2, and CaO, respectively. Detrital-authigenic index (DAI) calculated from the ash composition and its relation with AFT indicates Sialoferric nature of these coals. The correlation analysis, Principal Component Analysis (PCA), and Hierarchical Cluster Analysis (HCA) were used to study the possible fouling, slagging, and abrasion potentials in boilers during the coal combustion processes. A positive relationship between slagging and heating values of the coal has been found in this study.

  13. Waste Minimization Protocols for the Process of Synthesizing Zeolites from South African Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Leslie F. Petrik

    2013-04-01

    Full Text Available Production of a high value zeolite from fly ash has been shown to be an avenue for the utilization of South African fly ash which presently constitutes a huge disposal problem. The synthesis of zeolites Na-P1 and analcime on a micro-scale has been successful and preliminary investigation shows that scale-up synthesis is promising. However, the post-synthesis supernatant waste generated contains high levels of NaOH that may constitute a secondary disposal problem. A waste minimization protocol was developed to reduce the volume of waste generated with a view to enhancing the feasibility of the scale synthesis. Series of experiments were conducted in 100 mL jacketed batch reactors. Fly ash was reacted with 5 Mol NaOH on a 1:1 mass basis during the aging step, followed by hydrothermal treatment in which ultrapure water was added to the slurry. This study shows that by re-introducing the supernatant waste into the experiments in such a way that it supplies the required reagent (NaOH for the zeolite synthesis, zeolite Na-P1 and analcime can be synthesized. It also shows that the synthesis process can be altered to allow up to 100% re-use of the supernatant waste to yield high value zeolitic products. This study effectively constructed two protocols for the minimization of waste generated during the synthesis of zeolites from South African coal fly ash. This result could be used to establish a basis for legal and environmental aspects involved in the commission of a full-scale plant synthesizing zeolites NaP1 and analcime.

  14. In situ borehole determination of ash content of coal using gamma-gamma and neutron-gamma techniques

    International Nuclear Information System (INIS)

    During the past decade, borehole logging technology based on nuclear geophysics has found wide application in the Australian coal-mining industry. In response to the need for further improved accuracy in coal ash measurements, the Commonwealth Scientific and Industrial Research Organization, Division of Mineral Physics, has developed two new alternative techniques, which are both spectrometric. The spectrometric gamma-gamma technique is based on the existence of a simple correlation between the ash content and the equivalent atomic number and density of coal. The technique is spectrometric in that it records and uses the count rates in several windows of the backscatter spectrum. These count rates and their selected ratios describe the changes in spectral shape which are due to ash content variations. The spectrometric neutron-gamma method is suitable where the probe responses are required for specific elemental contents. Consequently, the method tolerates larger variations in ash composition for accurate measurement than does the gamma-gamma method. Both methods have been tested at several coal deposits in New South Wales and Queensland. For both techniques, RMS deviations between nuclear assay and chemical analysis are typically 2% ash in the range 5 to 40% ash. Both techniques are currently undergoing commercial development under the name of SIROLOG. The SIROLOG technology is designed to accommodate logging speeds up to 4m.min-1. However, the gamma-gamma probe uses gamma-ray sources of strength two orders of magnitude smaller than that of sources used in commercial probes. The logging system provides information on ash content in 5 cm intervals if required, although the vertical resolution of the probes is 30-35 cm. (author)

  15. Slag and ash chemistry after high-calcium lignite combustion in a pulverized coal-fired power plant

    OpenAIRE

    Papastergios, Georgios; Fernandez-Turiel, J. L.; Georgakopoulos, Andreas; Gimeno, D.

    2007-01-01

    More than 73% of the electrical power requirements of Greece are generated in lignite-fired power plants. Greece is the thirteenth largest coal and the fifth largest lignite producer in the world. The lack of domestic high-rank coals makes necessary to use low quality lignite for power generation in Greece. These lignites are characterized by a high water and ash content and a low calorific value. The low quality of such lignites generates important technical and environmental ...

  16. Coal fly ash interaction with environmental fluids: Geochemical and strontium isotope results from combined column and batch leaching experiments

    International Nuclear Information System (INIS)

    Highlights: ? Element release during fly ash extraction experiments controlled by mineralogy. ? Strontium isotopes in fly ash are not homogenized during coal combustion. ? Element correlations with 87Sr/86Sr indicate chemically resistant silicate phase. ? Sr isotopes can uniquely identify fly ash fluids leaking into the environment. - Abstract: The major element and Sr isotope systematics and geochemistry of coal fly ash and its interactions with environmental waters were investigated using laboratory flow-through column leaching experiments (sodium carbonate, acetic acid, nitric acid) and sequential batch leaching experiments (water, acetic acid, hydrochloric acid). Column leaching of Class F fly ash samples shows rapid release of most major elements early in the leaching procedure, suggesting an association of these elements with soluble and surface bound phases. Delayed release of certain elements (e.g., Al, Fe, Si) signals gradual dissolution of more resistant silicate or glass phases as leaching continues. Strontium isotope results from both column and batch leaching experiments show a marked increase in 87Sr/86Sr ratio with continued leaching, yielding a total range of values from 0.7107 to 0.7138. For comparison, the isotopic composition of fluid output from a fly ash impoundment in West Virginia falls in a narrow range around 0.7124. The experimental data suggest the presence of a more resistant, highly radiogenic silicate phase that survives the combustion process and is leached after the more soluble minerals are removed. Strontium isotopic homogenization of minerals in coal does not always occur during the combustion process, despite the high temperatures encountered in the boiler. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic composition of fly ash could be distinguishable from other sources and is a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and ground waters

  17. Study of ashes from municipal wastes incinerated in classical grate boilers and FBC units. Solidification of MWIR with FBC coal ashes for disposal

    Energy Technology Data Exchange (ETDEWEB)

    Blondin, J. [Centre d`Etudes et de Recherches du Charbon, Mazingarbe (France); Iribarne, A.P. [Univ. of Toronto, Ontario (Canada). Dept. of Chemical Engineering and Applied Chemistry; Anthony, E.J. [CANMET, Ottawa, Ontario (Canada). Energy Technology Centre

    1997-12-31

    FBC is now widely used to burn low quality coals because of its ability to meet environmental regulations, especially where SO{sub 2} emissions are of concern. The technology is also promising for a number of other fuels, especially those having high chloride contents. The characteristics of any fuel depend strongly on the combustion technique and temperature. Thus, FBC ashes would be expected to be substantially different from grate incinerator ashes. This study looks at the characteristics of ashes (MWIR) from municipal wastes, originated from various cities in Europe, and incinerated in FBC and classical grate furnace facilities. Information is also provided on the heavy metal contents and leaching characteristics of the various MWI residues. All the results are examined in light of possible utilization strategies and landfill regulations regarding the potential for co-disposal of incinerator ashes with coal derived residues from FBC boilers to render the monoliths inert and resistant against hazardous events that may occur during ultimated and definitive storage.

  18. ANN-GA based optimization of a high ash coal-fired supercritical power plant

    International Nuclear Information System (INIS)

    Highlights: ? Neuro-genetic power plant optimization is found to be an efficient methodology. ? Advantage of neuro-genetic algorithm is the possibility of on-line optimization. ? Exergy loss in combustor indicates the effect of coal composition on efficiency. -- Abstract: The efficiency of coal-fired power plant depends on various operating parameters such as main steam/reheat steam pressures and temperatures, turbine extraction pressures, and excess air ratio for a given fuel. However, simultaneous optimization of all these operating parameters to achieve the maximum plant efficiency is a challenging task. This study deals with the coupled ANN and GA based (neuro-genetic) optimization of a high ash coal-fired supercritical power plant in Indian climatic condition to determine the maximum possible plant efficiency. The power plant simulation data obtained from a flow-sheet program, 'Cycle-Tempo' is used to train the artificial neural network (ANN) to predict the energy input through fuel (coal). The optimum set of various operating parameters that result in the minimum energy input to the power plant is then determined by coupling the trained ANN model as a fitness function with the genetic algorithm (GA). A unit size of 800 MWe currently under development in India is considered to carry out the thermodynamic analysis based on energy and exergy. Apart from optimizing the design parameters, the developed model can also be used for on-line optimization when quick response is required. Furthermore, the effect of various coals on the thermodynamic performance of the optimized power plant is also determined.

  19. The bonding of heavy metals on nitric acid-etched coal fly ashes functionalized with 2-mercaptoethanol or thioglycolic acid

    International Nuclear Information System (INIS)

    Coal fly ash is a waste by-product of the coal fire industry, which generates many environmental problems. Alternative uses of this material would provide efficient solutions for this by-product. In this work, nitric acid-etched coal fly ash labelled with 2-mercaptoethanol or thioglycolic acid was assessed for retention of Al(III), As(III), Cu(II), Cd(II), Fe(III), Mn(II), Hg(II), Ni(II), Pb(II) and Zn(II) ions. The bonding characteristics between the organic compounds with the solid support, as well as with the metal ions, were evaluated using various surface analytical techniques. Visualization of the organically-functionalized coal fly ash particle was possible using scanning electron microscopy (SEM), while the elemental composition of the functionalized material, before and after retention of the metal ions, was obtained by energy dispersive (ED)-X ray spectrometry (XRS) and electrothermal atomic absorption spectrometry (ETAAS). Fourier transform infrared (FT-IR) spectrometry and Raman spectrometry were used to obtain information about the functional groups. It was found that some metal(oid) ions (As, Ni, Pb, Zn) were coordinated through the mercaptan group, while other metal(oid)s (Al, Cd, Cu, Fe, Hg, Mn) were apparently bonded to oxygen atoms. A low-cost and effective solid phase retention system for extraction of heavy metals from aqueous solutions was thus developed. - Graphical abstract: Nitric acid-etched coal fly ash labelled with 2-mercaptoethanol or thioglycolic acid was intended for the retention of heavy metals. The bonding characteristics between the organic compounds with the solid support, as well as with the metal ions, were evaluated using surface analytical techniques. - Highlights: • Coal fly ashes were organically-functionalized. • Organically-functionalized coal fly ashes were spectrometrically characterized. • Organically-functionalized coal fly ashes can be used as an effective solid sorbent for metal(oid)s. • This retention system provides a very promising future in designing effluent treatment systems

  20. Determination of sulfur in coal and ash slurry by high-resolution continuum source electrothermal molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nakadi, Flávio V.; Rosa, Lilian R.; Veiga, Márcia A.M.S. da, E-mail: mamsveiga@ffclrp.usp.br

    2013-10-01

    We propose a procedure for the determination of sulfur in coal slurries by high resolution continuum source electrothermal molecular absorption spectrometry. The slurry, whose concentration is 1 mg mL{sup ?1}, was prepared by mixing 50 mg of the sample with 5% v/v nitric acid and 0.04% m/v Triton X-100 and was homogenized manually. It sustained good stability. The determination was performed via CS molecular absorption at 257.592 nm, and the optimized vaporization temperature was 2500 °C. The accuracy of the method was ensured by analysis of certified reference materials SRM 1632b (trace elements in coal) and SRM 1633b (coal fly ash) from the National Institute of Standards and Technology, using external calibration with aqueous standards prepared in the same medium and used as slurry. We achieved good agreement with the certified reference materials within 95% confidence interval, LOD of 0.01% w/w, and RSD of 6%, which confirms the potential of the proposed method. - Highlights: • HR-CS ET MAS as a technique to determine sulfur in coal and ash • Utilization of (coal and coal fly ash) slurry as a sample preparation • Simple and fast method, which uses external calibration with aqueous standards without chemical modifier.

  1. Ancillary operations in coal preparation instrumentation on-line low cost sulfur and ash analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Malito, M.L.

    1991-07-01

    A program of design, fabrication, and field testing of an on-line sulfur and ash analyzer was undertaken by The Babcock Wilcox Company. The analyzer is intended for use on coal slurry streams such as those found at coal cleaning facilities. The analyzer design consists of a sample preparation and delivery system (SPAD) and an inductively coupled plasma atomic emission spectrometer (ICP-AES). The program consisted of the following major tasks: Selection and screening of delivery systems; Design of the analyzer system; Fabrication of SPAD system; Field testing of the SPAD system; and Laboratory ICP testing of field collected samples. The field testing was conducted at CQ Inc., (Homer City, Pa. pilot plant). Testing was completed without taking the ICP to the field, since the analysis of coal slurry by ICP had been demonstrated during the delivery system screening tests and the field tests were aimed primarily at demonstrating the performance of the SPAD system. Although the ICP was not deployed to the field, the subsequent laboratory testing of field collected samples simulated the performance of the entire system. 16 refs., 103 figs., 38 tabs.

  2. Determination of selected elements in whole coal and in coal ash from the eight argonne premium coal samples by atomic absorption spectrometry, atomic emission spectrometry, and ion-selective electrode

    Science.gov (United States)

    Doughten, M.W.; Gillison, J.R.

    1990-01-01

    Methods for the determination of 24 elements in whole coal and coal ash by inductively coupled argon plasma-atomic emission spectrometry, flame, graphite furnace, and cold vapor atomic absorption spectrometry, and by ion-selective electrode are described. Coal ashes were analyzed in triplicate to determine the precision of the methods. Results of the analyses of NBS Standard Reference Materials 1633, 1633a, 1632a, and 1635 are reported. Accuracy of the methods is determined by comparison of the analysis of standard reference materials to their certified values as well as other values in the literature.

  3. Alkaline hydrothermal conversion of fly ash precipitates into zeolites 3: The removal of mercury and lead ions from wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Vernon Somerset; Leslie Petrik; Emmanuel Iwuoha [University of the Western Cape, Bellville (South Africa). Sensor Research Laboratory, Department of Chemistry

    2008-04-15

    In this paper, the utilisation of zeolites synthesised from fly ash (FA) and related co-disposal filtrates as low-cost adsorbent material were investigated. When raw FA and co-disposal filtrates were subjected to alkaline hydrothermal zeolite synthesis, the zeolites faujasite, sodalite and zeolite A were formed. The synthesised zeolites were explored to establish its ability to remove lead and mercury ions from aqueous solution in batch experiments, to which various dosages of the synthesised zeolites were added. The test results indicated that when increasing synthesised zeolite dosages of 5-20 g/L were added to the acid mine drainage (AMD) wastewater, the concentrations of lead and mercury in the wastewater were reduced accordingly. The lead concentrations were reduced from 3.23 to 0.38 and 0.17 {mu}g/kg, respectively, at an average pH of 4.5, after the addition of raw FA zeolite and co-disposal filtrate zeolite to the AMD wastewater. On the other hand, the mercury concentration was reduced from 0.47 to 0.17 {mu}g/kg at pH=4.5 when increasing amounts of co-disposal filtrate zeolite were added to the wastewater. The experimental results had shown that the zeolites synthesised from the co-disposal filtrates were effective in reducing the lead and mercury concentrations in the AMD wastewater by 95% and 30%, respectively.

  4. Determination of selenium by ICP-MS and HG-ICP-MS in coal, fly ashes and sorbents used for flue gas cleaning

    OpenAIRE

    Díaz Somoano, Mercedes; López Antón, María Antonia; Martínez Tarazona, María Rosa

    2004-01-01

    The determination of selenium in solid materials related with the use of coal for energy production was evaluated by two methods; ICP-MS and HG-ICP-MS. Coals, fly ashes and various solids used as sorbents in gas cleaning processes (kaolin, limestone, alumina, metal oxide mixtures and activated carbons), were the materials analysed. In several of these materials, selenium could be determined by either method with similar results. However in coal, fly ashes and some activated carbons, the use o...

  5. Characterization of coal fly ash nanoparticles and induced oxidative DNA damage in human peripheral blood mononuclear cells

    Energy Technology Data Exchange (ETDEWEB)

    Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A. [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Ali, Al-Yousef Sulaiman [Department of Medical Laboratory Sciences, College of Applied Medical Science, University of Dammam, P.O. Box 1683, Hafr Al Batin-31991 (Saudi Arabia); Musarrat, Javed, E-mail: musarratj1@yahoo.com [Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Department of Agricultural Microbiology, Faculty of Agricultural Sciences, AMU, Aligarh202002 (India)

    2012-10-15

    The nano-sized particles present in coal fly ash (CFA) were characterized through the X-ray diffraction (XRD), transmission and scanning electron microscopy (TEM, SEM), atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) analyses. The XRD data revealed the average crystallite size of the CFA nanoparticles (CFA-NPs) as 14 nm. TEM and SEM imaging demonstrated predominantly spherical and some polymorphic structures in the size range of 11 to 25 nm. The amount of heavy metal associated with CFA particles ({mu}g/g) were determined as Fe (34160.0 {+-} 1.38), Ni (150.8 {+-} 0.78), Cu (99.3 {+-} 0.56) and Cr (64.0 {+-} 0.86). However, the bioavailability of heavy metals in terms of percent release was in the order as Cr > Ni > Cu > Fe in CFA-dimethyl sulfoxide (DMSO) extract. The comet and cytokinesis blocked micronucleus (CBMN) assays revealed substantial genomic DNA damage in peripheral blood mononuclear (PBMN) cells treated with CFA-NPs in Aq and DMSO extracts. About 1.8 and 3.6 strand breaks per unit of DNA were estimated through alkaline unwinding assay at 1:100 DNA nucleotide/CFA ppm ratios with the Aq and DMSO extracts, respectively. The DNA and mitochondrial damage was invariably greater with CFA-DMSO extract vis-a-vis -Aq extract. Generation of superoxide anions (O{sub 2} Bullet {sup -}) and intracellular reactive oxygen species (ROS) through metal redox-cycling, alteration in mitochondrial potential and 8-oxodG production elucidated CFA-NPs induced oxidative stress as a plausible mechanism for CFA-induced genotoxicity. -- Highlights: Black-Right-Pointing-Pointer CFA consists of spherical crystalline nanoparticles in size range of 11-25 nm. Black-Right-Pointing-Pointer Alkaline unwinding assay revealed single-strandedness in CFA treated ctDNA. Black-Right-Pointing-Pointer CFA nanoparticles exhibited the ability to induce ROS and oxidative DNA damage. Black-Right-Pointing-Pointer Comet and CBMN assays revealed DNA and chromosomal breakage in PBMN cells. Black-Right-Pointing-Pointer CFA-NPs resulted in mitochondrial membrane damage in PBMN cells.

  6. MCM-41 SYNTHESIZED FROM COAL FLY ASH AS A CATALYST IN THE PRODUCTION OF BIODIESEL USING PALM OIL.

    Directory of Open Access Journals (Sweden)

    M.R. DESHPANDE

    2013-05-01

    Full Text Available Coal fly ash was used to synthesize MCM-41 by alkali fusion followed by hydro- thermal treatment and was characterized using various techniques viz. XRD, SEM, FTIR, BET method for surface area measurement etc. The synthesis conditions were optimized to obtain highly crystalline MCM-41 with utmost BETsurface area 1102m2/g with high purity. The crystalline nature of the prepared MCM-41 was found to change with fusion temperature and a maximum value was obtained at 5500 C. The cost of synthesized MCM-41 was projected to be very few as compared to that of commercial MCM-41.This work presents the results of transesterification reaction using palm oil as feedstock with methanol and coal fly ash (CFA catalyst derived to produce methyl esters (biodiesel.The fly ash based catalyst was prepared using the wet impregnation procedure with different loadings of potassium. This was characterized by powder X-ray diffraction (XRD, SEM etc

  7. Research and development of coal ash off-belt bulk analyzer based on PGNAA technique using neutron source

    International Nuclear Information System (INIS)

    IAEA-RCA/RAS on NCS project have been operating from 2001 brought a new conception and approach about application of nuclear and nucleonic techniques in member states. Through 4 cycle of projects (RAS/8/089, RAS/8/094, RAS/8/099 and RAS/8/107), by a step-by-sep technical transfer, higher level on later phase, this technical transfer way has corrected disadvantages and opened new applications, helps the member states from passive receiving to active joining into higher level of technical development for particular application, in each member state. A regional demonstration centre has been set up in Hanoi - Vietnam, to train personnel from around the RCA region in the use of this instrumentation. The centre in Hanoi has been set a coal ash determination instruments using back-scattered gamma and coal ash logging instrument using PGNAA methods. In 2008, through project RAS/8/107, IAEA has aided a neutron generator and Vietnam had a responsibility to develop Ash content Bulk Analysis by PGNAA. Prompt gamma neutron activation analysis technique (PGNAA) is one among advanced techniques over the world. Advantages of this technique are fast analysis, good accuracy, sample process is not required, no influences of measurement environment and analysis of almost elements in the periodic table. Based on this issue, project Research and development of PGNAA coal ash analyser using neutron generator, carried out since 9/2009, finished in 9/2011 have achieved the first achievements in fast coal ash determination. Developed Ash content Bulk Analysis by PGNAA has following technical parameters: result of coal ash determined has absolute error less than 1%; uses Cf-252 neutron source with neutron flux of 0.85 x 106 n/s; uses BGO detector with size of 51 x 51mm, 2000 channels of ADC; analysis time is 600 s; mass of analysed coal sample is 700 kg; PC connected via USB interface on Window XP; neutron dose and gamma dose around the instruments are less than allowed doses in IAEA safety standards (allowed dose for radiation personnel is 5 ?Sv/h). The project has created out following procedures: procedure of coal ash analysis, procedure for calibration of ash content, procedure for processing of standard samples; user manual is also written. This Ash content Bulk Analysis by PGNAA system is using in laboratory, and its is needed to study and to improve more, to analyse not only ash content of coal buts also element contents and other parameters, such as moisture, volatiles content and so on of the coal; it is also needed to open new capability of measurements for other object (cement, soil), and changing the design to be a field an in-situ instrument. It is emphasized to improve this system and technique, step-by-step, to make it suitable for strict requirements of industry in industrialize-modernize process of Vietnam. By revealed advantages of PGNAA technique, this kind of system should be developed and improved to catch the fast development of automation in industry. (author)

  8. Amelioration of coal fly ash used as cereal crops growth media by sphagnum peat moss and soil

    OpenAIRE

    Bilski J. et al.

    2012-01-01

    Coal fly ash (FA) has a potential to be used as a soil amendment for growing plants. Toxicity of heavy metals present in FY, FA high salinity, and high pH of coal FA may potentially restrict or even prevent plant growth on the media with high concentration of FA. Sphagnum peat moss (SPM) shows a potential to ameliorate coal FA based plant media by improving the texture of such media, making media less harder, decreasing high pH of the media, and potentially binding heavy metals present in FA....

  9. Major, minor, and trace element composition of coal and fly ash, as determined by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    A highly sensitive instrumental neutron activation analysis (INAA) technique can determine 30 to 40 elements in coal and fly ash including Sb, As, Se, Hg, Zn, and V which are elements of environmental concern. This multi-element capability makes possible the detailed chemical analysis of coal and combustion products. A comparison to National Bureau of Standards--Environmental Protection Agency fuel standards shows that a high degree of accuracy and precision is attainable, allowing tentative conclusions to be drawn as to the origin of certain elements in the coal and their fate during combustion. (U.S.)

  10. Application and feasibility of coal fly ash and scrap tire fiber as wood wall insulation supplements in residential buildings

    International Nuclear Information System (INIS)

    Each year, nearly 55% of the fly ash (FA) produced by coal burning power plants in the United States is disposed of in landfills and ash ponds, while the amount of recycled fiber from scrap tires that is beneficially used in end-user markets is virtually negligible. This paper presents the results of a study carried out to investigate whether it might be possible to increase the thermal efficiency of a light-frame residential structure through addition of a fly ash-scrap tire fiber composite to traditional fiberglass insulation in light-frame wood residential construction. This type of construction represents more than 80% of the building stock in North America. The results of this study suggest that the fly ash-scrap tire fiber composite provides a sustainable supplement to traditional insulation that not only increases the efficiency of traditional insulation but can also help significantly reduce the environmental issues associated with disposal of these waste products. (author)

  11. Remoção de íons Zn2+, Cd2+ e Pb2+ de soluções aquosas usando compósito magnético de zeólita de cinzas de carvão Removal of Zn2+, Cd2+ e Pb2+ ions from aqueous solutions by magnetic composite of zeolite from coal ashes

    OpenAIRE

    Denise Alves Fungaro; Mitiko Yamaura; José Eduardo Alves Graciano

    2010-01-01

    For this study, magnetic composite of zeolite-magnetite was prepared by mixing magnetite nanoparticles suspension with synthetic zeolite. The nanoparticles in suspension were synthesized by precipitating iron ions in a NaOH solution. The zeolite was synthesized from coal fly ash by alkaline hydrothermal treatment. The magnetic composite was characterized by XDR, SEM, magnetization measurements, IR, and BET surface area. Batch tests were carried out to investigate the adsorption of metal ions ...

  12. Uranium in coal and fly ash: Abundance, forms, and environmental significance

    International Nuclear Information System (INIS)

    The purpose of this report is to summarize recent studies within the US Geological Survey (USGS) that further define the abundance, form, and leachability of uranium in coal and fly ash. Uranium was chosen from the hazardous air pollutant elements because the application of fission-track radiography provided some unique observations of the spatial distribution of uranium on a microscopic scale. Radiation-based measurements of uranium abundance by low energy gamma-ray spectrometry also provided informative determinations of long-lived uranium decay products of environmental concern, i.e. 226Ra and 210Pb. Accurate determinations of the distribution, abundance, and leachability of uranium have broad applicability as a basis for comparison with other less mobile actinide elements such as Th, and with other hazardous air pollutant elements that may share some similar chemical properties

  13. Synthesis and characterization of zeolite from coal ashes modified by cationic surfactant

    International Nuclear Information System (INIS)

    Zeolite synthesized from coal fly ash was modified with different concentrations (2 and 20 mmol.L-1) of hexadecyltrimethylammonium bromide (HDTMA-Br). The Non-Modified Zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) were characterized by X-ray fluorescence spectrometry, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, thermogravimetric analysis, among others. The SMS presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of NMZ. A decrease in surface area was observed for SMZ as compared to NMZ indicating zeolite surface coverage with HDTMA-Br molecules. The crystalline nature of the zeolite remained intact after adsorption of surfactant and heating for drying. FTIR analysis indicated that there were no significant changes in the structure of the zeolite after adsorption of surfactant. (author)

  14. [Affine magnetic sorbents supported on coal ash microspheres for recombinant protein isolation].

    Science.gov (United States)

    Frank, L A; Borisova, V V; Vereshchagina, T A; Fomenko, E V; Anshits, A G; Gitel'zon, I I

    2009-01-01

    The results of the development and utilization of an affine magnetic sorbent with Ni2+ ions immobilized on coal ash microspheres are reported. The applicability of the material in the isolation of Histag proteins is demonstrated by examples of the recombinant green fluorescent protein from Clytia gregarium and the Ca2+ regulated photoprotein obelin from Obelia longissima. The specific sorption capacity of the sorbent was 2-7 mg/cm3 for medium-size proteins (20-30 kDa). The particles are suitable for chromatography with the presence of chaotropic agents and EDTA. They are easy to manipulate as isolation of a target protein takes 30-35 min. On one hand, the elevated affinity of the sorbent to proteins rich in native histidines may result in a high degree of irreversible sorption; on the other hand, it allows isolation of such proteins without the introduction of artificial polyhistidine tracts. PMID:19382714

  15. Nano-crystal glass-ceramics obtained from high alumina coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Fei Peng; Kai-ming Liang; An-min Hu [Tsinghua University, Beijing (China). Department of Materials Science and Engineering

    2005-03-01

    Glass has been obtained by melting high alumina coal fly ash with fluxing additives. A thermal treatment was employed to convert the obtained glass into nano-crystal glass-ceramics. X-ray diffraction (XRD) patterns show that the main crystalline phases in both the glass-ceramics are anorthite (CaAl{sub 2}Si{sub 2}O{sub 8}) and wollastonite (CaSiO{sub 3}). The crystals are homogeneously dispersed within the parent glass. The average crystal size is below 200 nm. Physical and mechanical properties, such as density, thermal expansion coefficient, hardness, and bending strength, of the glass have been examined and the corresponding microstructures are discussed. The results demonstrate that the glass-ceramics have potential for a wide range of construction applications. 18 refs., 8 figs., 3 tabs.

  16. Nano-crystal glass-ceramics obtained by crystallization of vitrified coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Fei Peng; Kaiming Liang; Anmin Hu; Hua Shao [Tsinghua University, Beijing (China). Department of Material Science and Engineering

    2004-10-01

    Glass has been obtained by melting coal fly ash from a power plant in North China with Na{sub 2}O+CaO and BaO+CaO as fluxing additives. A thermal treatment was employed to convert the obtained glass to nano-crystal glass-ceramics. X-ray diffraction patterns show that the main crystalline phase in both the glass-ceramics is wollastonite (CaSiO{sub 3}). The crystals are homogeneously dispersed within the parent glass. The average crystal size is below 300 nm, and varies according to heat treatment process used. Physical and mechanical properties, such as density, thermal expansion coefficient, hardness, and bending strength, of the two glasses have been examined and the corresponding microstructures are discussed. The results demonstrate that both glass-ceramics have potential for a wide range of construction application. 14 refs., 5 figs., 3 tabs.

  17. Experimental study of the powder abrasion characteristics of materials used for coal ash pneumatic transport pipes

    Energy Technology Data Exchange (ETDEWEB)

    Mori, T.; Ono, H.; Nishiyama, Y.; Takase, T.

    1985-01-01

    In order to clarify the powder abrasion characteristics of the materials used for coal ash pneumatic transport pipes, sand blasting type apparatus was employed in a series of tests designed to provide a close simulation of the conditions encountered in actual pneumatic transport pipeline systems. Regarding the materials used in straight runs of pipe, it was found that the resistance of a low-carbon steel to powder abrasion was roughly the same as that of medium carbon steel. In other words, it is thought that material hardness has relatively little effect on wear resistance when the hardness of the abrasive powder is very much greater than that of the material. Regarding the materials used for curved sections of pipe, the powder abrasion observed on borided materials was very much less than that seen on high chromium cast iron. It was also confirmed that the effectiveness of boriding is dependent on the thickness of the boride layer. 11 references.

  18. SO{sub 2} adsorption on type Y zeolites synthesized from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Roberto Juan; M. Teresa Izquierdo; Begona Rubio; Carmen Ruiz [Instituto de Carboquimica (CSIC), Zaragoza (Spain)

    2007-07-01

    Zeolite Y was prepared from commercial zeolite building materials, following verified procedures. On the other hand, coal combustion fly ash was used as a source of silica to prepare zeolite Y, using pure chemicals as a source of alumina. Both materials were exhaustively characterized by chemical analysis, X-ray diffraction, N{sub 2} adsorption and scanning electron microscopy The SO{sub 2} adsorption experiments in this work were carried out at 100{sup o}C of temperature, under constant atmospheric temperature and spatial velocity of 1015 h{sup -1}. SO{sub 2} removal capacity of fresh samples is high, decreasing to an almost constant value after some cycles of adsorption/desorption. 6 refs., 7 figs., 3 tabs.

  19. Chemical and technological characteristics of middle-Miocene brown coal from the Lyskow region and ashes from its combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ciuk, E. (Panstwowy Instytut Geologiczny, Warsaw (Poland))

    1990-02-01

    Evaluates properties of brown coal from the Lyskow deposit, situated to the south of Tuchola. The seam is situated at depths from 28.5 to 30.6 m and is 2.1 m thick. The coal has a carbon content of 60.14% and hydrogen content of 4.89% and is characterized by a volatile matter content of 61.76%, sulfur content of 0.64%, calorific value of 8,599 kJ/kg and ash content of 15.99%. Coal from the Lyskow deposit is characterized as power coal (due to a high xylite content of about 54.28% it cannot be classified as suitable for briquetting). Silica, calcium oxides and sulfur trioxide predominate in ashes. Content of iron and aluminium oxides is low. Ashes from coal combustion are characterized by a low melting point. Slag buildup on the heating elements of a boiler used for its combustion is characterized as low. 7 refs.

  20. Survey and conceptual flow sheets for coal conversion plant handling-preparation and ash/slag removal operations

    Energy Technology Data Exchange (ETDEWEB)

    Zapp, F.C.; Thomas, O.W.; Silverman, M.D.; Dyslin, D.A.; Holmes, J.M.

    1980-03-01

    This study was undertaken at the request of the Fossil Fuel Processing Division of the Department of Energy. The report includes a compilation of conceptual flow sheets, including major equipment lists, and the results of an availability survey of potential suppliers of equipment associated with the coal and ash/slag operations that will be required by future large coal conversion plant complexes. Conversion plant flow sheet operations and related equipment requirements were based on two representative bituminous coals - Pittsburgh and Kentucky No. 9 - and on nine coal conversion processes. It appears that almost all coal handling and preparation and ash/slag removal equipment covered by this survey, with the exception of some coal comminution equipment, either is on hand or can readily be fabricated to meet coal conversion plant capacity requirements of up to 50,000 short tons per day. Equipment capable of handling even larger capacities can be developed. This approach appears to be unjustified, however, because in many cases a reasonable or optimum number of trains of equipment must be considered when designing a conversion plant complex. The actual number of trains of equipment selected will be influenced by the total requied capacity of the complex, the minimum on-line capacity that can be tolerated in case of equipment failure, reliability of specific equipment types, and the number of reactors and related feed injection stations needed for the specific conversion process.

  1. Nitric Oxide Removal from Flue Gases by Carbon-enriched Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    Begoña Rubio

    2013-04-01

    Full Text Available The aim of this work is to evaluate the characteristics of activated and non-activated carbon obtained from carbon-enriched coal fly ashes (CECFA from two different power stations to be used in the low temperature reduction of NO from stack gases. Carbon-rich fractions were obtained by mechanical sieving of fly ashes and by oil agglomeration. Activation of some samples was carried out in steam at 900ºC in order to develop porosity onto the samples. The obtained activated and non-activated samples were characterised by several techniques and their nitric oxide removal capacity at a low temperature using ammonia as a reducing agent was evaluated (gas conditions: 150 ºC, 1000 µL/L  NO, 1200 µL/L  NH3 , 60 mL/L O2, Ar as balance. CECFA obtained only by sieving had carbon content varying from 1 %   to 47 %, and NO reduction levels varying from 3 % to 29%. CECFA L2A and E2A, obtained by sieving, agglomeration and further activation, contained 66 % and 57 % of carbon respectively, and their NO conversion was 36 % and 48%. BET surface areas of CECFA samples before activation were in all cases below 20 m2/g. In the case of activated samples, L2A and E2A the surface area increased to 217 and 395 m2/g respectively. In all cases, and comparing samples with the same carbon content, CECFA coming from Escucha demonstrated higher NO conversion capacity. The obtained results show that carbon content, surface area and parent coal type are the main parameters that influence the NO removal capacity of the obtained CECFA.DOI: http://dx.doi.org/10.5755/j01.erem.63.1.2823

  2. Carbonation of brine impacted fractionated coal fly ash: implications for CO2 sequestration.

    Science.gov (United States)

    Nyambura, Muriithi Grace; Mugera, Gitari Wilson; Felicia, Petrik Leslie; Gathura, Ndungu Patrick

    2011-03-01

    Coal combustion by-products such as fly ash (FA), brine and CO(2) from coal fired power plants have the potential to impact negatively on the environment. FA and brine can contaminate the soil, surface and ground water through leaching of toxic elements present in their matrices while CO(2) has been identified as a green house gas that contributes significantly towards the global warming effect. Reaction of CO(2) with FA/brine slurry can potentially provide a viable route for CO(2) sequestration via formation of mineral carbonates. Fractionated FA has varying amounts of CaO which not only increases the brine pH but can also be converted into an environmentally benign calcite. Carbonation efficiency of fractionated and brine impacted FA was investigated in this study. Controlled carbonation reactions were carried out in a reactor set-up to evaluate the effect of fractionation on the carbonation efficiency of FA. Chemical and mineralogical characteristics of fresh and carbonated ash were evaluated using XRF, SEM, and XRD. Brine effluents were characterized using ICP-MS and IC. A factorial experimental approach was employed in testing the variables. The 20-150 ?m size fraction was observed to have the highest CO(2) sequestration potential of 71.84 kg of CO(2) per ton of FA while the >150 ?m particles had the lowest potential of 36.47 kg of CO(2) per ton of FA. Carbonation using brine resulted in higher degree of calcite formation compared to the ultra-pure water carbonated residues. PMID:20970918

  3. Bioaccumulation of selenium from coal fly ash and associated environmental hazards in a freshwater fish community

    International Nuclear Information System (INIS)

    Bioaccumulation of Se by fish from Pigeon River and Pigeon Lake, Michigan, which receive inputs of Se from a coal fly-ash disposal facility, was studied to assess potential hazards of Se toxicity to fish and wildlife. Se concentrations in fish from sites receiving Se inputs from fly ash disposal ponds were significantly greater than concentrations in fish from upstream sites, which were near normal background concentrations. Se bioaccumulation differed substantially among fish species, especially in the most contaminated site, where whole-body Se concentrations for the five species analyzed ranged from 1.4 to 3.8 microg/g (wet wt.). The top predator in the community, northern pike (Esox lucius), had Se concentrations less than those in likely prey species. Among lower-order consumers, Se concentrations were greater in limnetic species (spottail shiner, Notropis hudsonius, and yellow perch, Perca flavescens), than in benthic species (white sucker, Catostomus commersoni, and rock bass, Ambloplites rupestris). Se concentrations in tissues of fish from the lower Pigeon River and Pigeon Lake approached, but did not exceed lowest observable effect concentrations (LOAECs) for Se in tissues of sensitive fish species. However, Se concentrations in several fish species exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals, suggesting that consumption of fish in these areas may pose a hazard to piscivorous wildlife

  4. The Swedish Ash Programme 2002-2008. Biomass, wastes, peat - any solid fuel but coal

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem, Henrik; Herbert, Roger

    2009-07-15

    In Sweden, producers of combustion residues have since 2002 implemented a collaborative applied RandD programme aimed at the utilisation of combustion residues (ash). The fuels are biomass, wastes, peat - any solid fuel but coal. In this report, the main lines of the programme are described: Covers for landfills and mine tailings; Civil works, e.g. road-buildings, where both geotechnical and environmental questions have been addressed; Cement and concrete applications; Compensating soils for removing biomass and the mineral nutrients in the biomass. The emphasis of the Programme is on environmental questions, even if technical questions have been treated. The time perspective in this context is much longer than the 3-5 years that are usual in an applied RandD programme, i.e. decades after ash has been placed on a site, e.g. in a road, or spread to forest soil. New test fields have been created in the programme and old test fields have been evaluated in order to gather available information

  5. Trace elements in lake sediments, macrozoobenthos and fish near a coal ash disposal basin

    Energy Technology Data Exchange (ETDEWEB)

    Hatcher, C.O.; Ogawa, R.E.; Poe, T.P.; French, J.R.P. (National Fisheries Research Center-Great Lakes, Ann Arbor, MI (USA). US Fish and Wildlife Service)

    1992-09-01

    Samples of lake sediment, macrozoobenthos, and fish were collected during 1983 and 1984 near a coalash disposal basin situated on the western shoreline of Lake Erie. Neutron activation analysis was used to determine if potentially toxic trace elements were present in higher concentrations at stations near the basin than at reference stations a few kilometres away. Of the 29 trace elements examined, arsenic and cobalt were significantly (p [lt] 0.05) more concentrated in sediment nearest the coal ash basin except in spring, when little or no difference was detected. Arsenic and bromine were significantly higher in oligochaetes and chironomids taken from proximal stations than in those taken from reference stations. Selenium, bromine, cobalt, nickel, and chromium were higher in young-of-the year brown bullheads taken nearer the disposal basin in fall 1983. Selenium was higher in adult spottail shiners taken at the proximal station in spring 1984, and bromine was higher in yearling white bass from the proximal station in fall 1983 and 1984. None of the trace elements was higher in adult yellow perch or adult brown bullheads at any time. Fewer spottail shiners and yearling white bass were caught close to the disposal basin than far away, which may indicate avoidance by these fish of increased concentrations of trace elements contained within the ash effluent.

  6. Evaluation of Some Parameters in Relation to Hydraulic Stowing of Pond Ash in Underground Coal Mines: A Prototype Study

    Science.gov (United States)

    Mishra, D. P.; Das, S. K.

    2015-04-01

    Various parameters in relation to hydraulic stowing of pond ash such as rate of water drainage from the pond ash, water absorption by the pond ash, percentage of stowing and percentage of void were evaluated using a mine goaf model stowed with pond ash slurries of five concentrations varying from 45 to 65 % at 5 % increment to identify the suitable slurry concentration for effective stowing in underground coal mines. The study revealed that the rate of water drainage from the stowed pond ash is highest during the initial 15 min of stowing and it gradually decreases with time. Also, it was observed that the percentages of water absorption by the pond ash and stowing increase with the increment of slurry concentration. It was concluded that pond ash slurries of higher concentrations such as 60 and 65 %, which yield better results in terms of higher stowing percentage in the 1st phase of stowing itself and higher water absorption, may be considered appropriate for stowing.

  7. Coal Ash Aerosol in East Asian Outflow as a Source for Oceanic Deposition of Iron and Other Metals

    Science.gov (United States)

    Anderson, J. R.; Hua, X.

    2008-12-01

    While ocean deposition of East Asian dust is given significant emphasis as a source of biologically-active trace elements, iron in particular, dust events are episodic and highly seasonal. There is, however, a constant source of aerosol that is chemically similar to dust (albeit amorphous in structure rather than crystalline) in the ash particles emitted from many hundreds of coal-fired power plants that are sited along the entire coastal region of China and Korea. The emission controls on these facilities vary widely and, in even cases of state-of-the-art emission controls, the secondary release of ash can be significant. There are of course even more small industrial and household sources of coal combustion emissions, in most cases with little or no emissions controls. Ash from a modern coal-fired power facility in Korea has been examined chemically and morphologically with electron microscopic techniques. As is characteristic of all such facilities, two principal types of ash are present: (1) flyash, silicate glass spheres that are emitted with the smoke and removed by electrostatic precipitators; and (2) bottom ash, "clinkers" and noncombustible material sticking to the furnace walls that are mixed with water and ground after cooling, then removed as a slurry to a dumping area. In addition, iron sulfide (pyrite) is a common constituent of coal and provides both a source of sulfur dioxide gas and also molten iron spherical particles in the ash. The iron spheres then are rapidly oxidized upon cooling. Bottom ash is a more complex material than flyash in that it contains more iron and other trace metals, plus it contains varying amounts of uncombusted carbon. The post-combustion handling of bottom ash can lead to significant emissions despite the fact that little or none goes out the stack. The iron oxide spheres can also be emitted by this secondary method. The concentrations of ash can be very high in close proximity to power plants (PM10 of several hundred micrograms per cubic meter of air) and traces of these aerosols have been found in the ACE-Asia and PACDEX experiments above the Sea of Japan, the Yellow Sea and across the width of the North Pacific.

  8. The effects of alkaline dosage and Si/Al ratio on the immobilization of heavy metals in municipal solid waste incineration fly ash-based geopolymer.

    Science.gov (United States)

    Zheng, Lei; Wang, Wei; Shi, Yunchun

    2010-04-01

    The present research explored the application of geopolymerization for the immobilization and solidification of municipal solid waste incineration (MSWI) fly ash. The influence of alkaline activator dosage and Si/Al molar ratio on the compressive strength and microstructure of MSWI fly ash-based geopolymer was investigated. A geopolymer with the highest strength was identified to occur at an intermediate alkaline activator dosage and Si/Al ratio, and the optimal Na/MSWI fly ash and Si/Al molar ratio was close to 2.8 mol kg(-1) and 2.0, respectively. IR spectra showed that higher alkaline activator dosage enhanced the structural disruption of the original aluminosilicate phases and a higher degree of polymerization of the geopolymer networks. At low Si/Al ratio, there was an increasing number of tetrahedral Al incorporating into the silicate backbone. As the Na/MSWI fly ash ratio increased, the microstructure changed from containing large macropores to more mesopores and micropores, indicating that more geopolymers are formed. Furthermore, the pore volume distribution of geopolymers was observed to shift to larger pores as the Si/Al ratio increased, which suggests that the soluble silicon content serves to reduce the amount of geopolymers. Heavy metal leaching was successfully elucidated using the first-order reaction/reaction-diffusion model. Combining the results from the microstructure of samples with the kinetic analysis, the immobilization mechanism of Cr, Cu, and Zn was inferred in this study. The methodologies described could provide a powerful set of tools for the systematic evaluation of element release from geopolymers. PMID:20304461

  9. Determination of uranium concentrations and its activity ratios in coal and fly ash from Philippine coal-fired thermal power plants using ICP-MS and TIMS

    International Nuclear Information System (INIS)

    The specific activity of 238U as a technologically enhanced naturally occurring radioactive material (TENORM) in feed coal, bottom and fly ash samples from four major coal-fired thermal power plants in the Philippines have been measured using high-resolution gamma-ray spectroscopy system equipped with a high-purity germanium (HPGe) detector. The uranium concentration has been determined from same samples using inductively coupled plasma mass spectrometry (ICP-MS). There was a good correlation between the measured uranium using both methods and has been estimated to be 0.98. Uranium from coal, bottom and fly ash samples were chemically separated and activity ratio (234U/238U) and 235U/238U ratio was measured using a thermal ionization mass spectrometer (TIMS). The highest concentration of uranium was found in fly ash and lowest was for feed coal. Uranium isotopic composition plays an important role in studying its biogeochemical behavior and is a good tracer on the sources of uranium in the environment. (orig.)

  10. Identification of admixture for pelletization and strength enhancement of sintered coal pond ash aggregate through statistically designed experiments

    International Nuclear Information System (INIS)

    Highlights: • Sintered aggregate using pond ash from lignite and bituminous coal source. • Identification of admixtures and its dosage through design of experiments. • Clay, bentonite and kaolinite as binders enhance the strength of aggregate. • Use of calcium hydroxide with clay binder enhanced pelletization efficiency. • Use of borax with clay binders enhanced the strength of aggregate. - Abstract: Statistically designed experiments using Response Surface Methodology have been undertaken to identify the parameters influencing manufacturing process and properties of aggregate using coal pond ash (generated from bituminous and lignite coal sources). Based on the preliminary studies, Ca(OH)2 and borax have been identified as pelletization and strength enhancing admixture respectively. Pelletization efficiency of bituminous and lignite pond ash increased with an increase in binder and Ca(OH)2 dosage to 20–98% and 50–98% respectively, with proportionate quantity of water. Sintering has been used as a hardening method with temperature range of 900 °C and 1100 °C for a duration range of 45–120 min. Phase composition and sintered microstructure of aggregate has been reported using X-ray diffraction and scanning electron microscopy respectively. The ten percent fines value of aggregate with clay binder was 5.5 tonne as against a value of 4.5 tonne with aggregate with bentonite binder. Among the binders studied, bentonite resulted in high volume utilization of pond ash, i.e. up to 88%

  11. Use of zeolitised coal fly ash for landfill leachate treatment: A pilot plant study

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Y.; Otal, E.; Vilches, L.F.; Vale, J.; Querol, X.; Pereira, C.F. [University of Seville, Seville (Spain)

    2007-07-01

    Treatment of municipal solid waste (MSW) landfill leachate generally results in low percentages of nutrient removal due to the high concentration and accumulation of refractory compounds. For this reason, individual physical, chemical and biological processes have been used for the treatment of raw landfill leachate and sometimes for the mixture of domestic wastewater and landfill leachate. In this work, the possibility of treating landfill leachate was tested in a bench-scale pilot plant by a two-step method combining adsorption and coagulation-flocculation. Zeolite synthesized from coal fly ash, a by-product of coal-fired power stations, was used in this study both as a decantation aid reagent and as an adsorbent of COD and NH{sub 4}-N. The coagulation-flocculation step was performed by the use of aluminium sulphate and a polyelectrolyte (ACTIPOL A-401). The leachate was collected directly from a storage unit of the organic fraction of MSW, before it was composted. For this reason the raw leachate was diluted before treatment. The sludge was recirculated to enhance the removal efficiency of nutrients as well as to optimize flocculant saving and to decrease sludge production. The results showed that it is possible to remove 43%, 53% and 82% of COD, NH{sub 4}-N, and suspended solids, respectively. Therefore, this method may be an alternative for ammonium removal, as well as a suitable pre- or post-treatment step, in combination with other processes in order to meet regulatory limits.

  12. Reproduction and hatchling performance in freshwater turtles associated with a remediated coal fly-ash spill.

    Science.gov (United States)

    Steen, David A; Van Dyke, James U; Jackson, Brian P; Hopkins, William A

    2015-04-01

    In 2008 an impoundment retaining wall failed at the Tennessee Valley Authority's coal burning plant in Kingston, Tennessee, releasing large quantities of coal-fly ash into the Emory River. Following extensive remediation of the spill, we captured (in 2011 and 2012) gravid turtles of multiple species in three rivers (two impacted and one reference) within the vicinity of the spill to determine whether there was evidence of the spill influencing reproduction. There was little evidence that river of origin affected reproductive output, hatching success, hatchling size, or hatchling locomotor performance. Although hatching success and hatchling righting ability of pond sliders, Trachemys scripta, was higher in our reference river than in the Emory or Clinch River, respectively, these differences could not be attributed to differences in individual element concentrations in turtle tissues and effect sizes were relatively small. For example, hatching success was reduced by 11% in the spill zone compared to the reference river, an effect that is unlikely substantial enough to influence local population dynamics in light of turtle life history. Our results suggest that residual contamination that remains in the Emory-Clinch system after its remediation poses low risk of excessive element exposure and limited adverse reproductive effects to freshwater turtles. Future monitoring could reveal whether the observed reduction in hatching success gradually attenuates with time, or whether any long-term effects of chronic exposure to low-level contamination emerge over time. PMID:25682257

  13. Temperature effect on the pressure drop across the cake of coal gasification ash formed on a ceramic filter

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Liang, Y.; Sakong, K.M.; Choi, J.H.; Bak, Y.C. [Gyeongsang National University, Jinju (Republic of Korea). Dept. of Biology & Chemical Engineering

    2008-01-15

    In order to predict the pressure drop across the cake of coal gasification (CG) ash formed on ceramic filter, an empirical equation was developed taking into account several factors, such as the face velocity, ash load, shape factor and size of particles, and especially the operating temperature. The hot air stream of well classified fine particles of CG ash was simulated as the syngas derived from the coal gasification process. The pressure drop behavior and cleaning efficiency of the filter were carefully investigated within the temperature range from room temperature to 673 K. The pressure drop across the ash cake was dominantly governed by the air viscosity, which increased with temperature. It was well expressed by the previously reported-empirical equation (J.H. Choi, Y.C. Bak, H.J. Jang, J.H. Kim, and J.H. Kim, Korean J. Chern. Eng., 21(3) (2004) 726.) with the modification of the viscosity term in the equation for different temperatures. The residual pressure drop rate across the ash cake also increased while the cleaning efficiency of the ceramic filter decreased as temperature increased.

  14. The occurrence of hazardous volatile elements and nanoparticles in Bulgarian coal fly ashes and the effect on human health exposure

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luis F.O., E-mail: lfsoliveira@univates.br [Centro Universitario Univates, Pro Reitoria de Pesquisa Estensao e Pos Graduacao, Programa de Pos Graduacao Ambiente e Desenvolvimento (Brazil); Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); DaBoit, Katia [Department of Environmental Medicine, Catarinense Institute of Environmental Research and Human Development - IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Sampaio, Carlos H. [Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Goncalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre - RS (Brazil); Jasper, Andre [Centro Universitario Univates, Pro Reitoria de Pesquisa Estensao e Pos Graduacao, Programa de Pos Graduacao Ambiente e Desenvolvimento (Brazil); Andrade, Maria L. [Department of Plant Biology and Soil Science, University of Vigo, 36310 Vigo (Spain); Kostova, Irena J. [Sofia University ' St. Kliment Ohridski' , Department of Geology, Paleontology and Fossil Fuels, 15, Tzar Osvoboditel Blvd., 1000 Sofia (Bulgaria); and others

    2012-02-01

    Low-rank, high-mineral matter Bulgarian coals were studied using a variety of chemical, optical, and electron beam methods. The larger fly ash carbon phases include charred carbons in contrast to coked carbons present in the fly ashes of bituminous-coal-derived fly ashes. Nanoscale carbons include multi-walled carbon nanotubes (MWCNTs) encapsulating Hg, Se, and As, among other elements. In addition to the glass which dominates the fly ash, relatively coarse 'rock fragments', consisting of an unmelted to partially melted core surrounded by a glassy rim, are present in the fly ash. Nano-scale minerals can contain hazardous elements and, along with metal-bearing multiwalled nanotubes, can be a path for the entry of hazardous particles into the lungs and other organs. Highlights: Black-Right-Pointing-Pointer We model Bulgarian power plants which have regulated minerals nanoparticles can contain hazardous elements. Black-Right-Pointing-Pointer We study changes in the level of information about nanominerals importance and the effect on human health exposure. Black-Right-Pointing-Pointer Increasing information will increase quality if power plants procedures are similar.

  15. Effective utilization of waste ash from MSW and coal co-combustion power plant-Zeolite synthesis

    International Nuclear Information System (INIS)

    The solid by-product from power plant fueled with municipal solid waste and coal was used as a raw material to synthesize zeolite by fusion-hydrothermal process in order to effectively use this type of waste material. The effects of treatment conditions, including NaOH/ash ratio, operating temperature and hydrothermal reaction time, were investigated, and the product was applied to simulated wastewater treatment. The optimal conditions for zeolite X synthesis were: NaOH/ash ratio = 1.2:1, fusion temperature = 550 deg. C, crystallization time = 6-10 h and crystallization temperature = 90 deg. C. In the synthesis process, it was found that zeolite X tended to transform into zeolite HS when NaOH/ash ratio was 1.8 or higher, crystallization time was 14-18 h, operating temperature was 130 deg. C or higher. The CEC value, BET surface area and pore volume for the synthesized product at optimal conditions were 250 cmol kg-1, 249 m2 g-1 and 0.46 cm3 g-1 respectively, higher than coal fly ash based zeolite. Furthermore, when applied to Zn2+ contaminated wastewater treatment, the synthesized product presented larger adsorption capacity and bond energy than coal fly ash based zeolite, and the adsorption isotherm data could be well described by Langmuir and Freundlich isotherm models. These results demonstrated that the special type of co-combustion ash from power plant is suitable for synthesizing high quality zeolite, and the products are suitable for heavy metal removal from wastewater

  16. Notes on the Potential for the Concentration of Rare Earth Elements and Yttrium in Coal Combustion Fly Ash

    Directory of Open Access Journals (Sweden)

    James C. Hower

    2015-06-01

    Full Text Available Certain Central Appalachian coals, most notably the Fire Clay coal with a REY-enriched volcanic ash fall tonstein, are known to be enriched in rare earth elements. The Fire Clay tonstein has a greater contribution to the total coal + parting REY than would be inferred from its thickness, accounting for about 20%–35% of the REY in the coal + parting sequence. Underground mining, in particular, might include roof and floor rock and the within-seam partings in the mined product. Beneficiation, necessary to meet utility specifications, will remove some of the REY from the delivered product. In at least one previously published example, even though the tonstein was not present in the Fire Clay coal, the coal was enriched in REY. In this case, as well as mines that ship run-of-mine products to the utility, the shipped REY content should be virtually the same as for the mined coal. At the power plant, however, the delivered coal will be pulverized, generally accompanied by the elimination of some of the harder rock, before it is fired into the boiler. Overall, there are a wide range of variables between the geologic sample at the mine and the power plant, any or all of which could impact the concentration of REY or other critical materials in the coal combustion products.

  17. Composition and sintering characteristics of ashes from co-firing of coal and biomass in a laboratory-scale drop tube furnace

    International Nuclear Information System (INIS)

    In this study ash Ts (sintering temperature) is proposed as an index to evaluate deposition propensity during coal and biomass co-firing. The experiments were carried out in a drop-tube furnace and the resulting ash samples were collected. Ts of the ash samples was measured with a pressure-drop sintering device. The chemical compositions and mineral phase characteristics of the ashes were also analyzed using ICP (inductively coupled plasma), SEM (scanning electron microscope) and XRD (X-ray diffraction), respectively. Ts decreased with increasing the mass ratio of biomass to coal with a non-linear relationship. The straw showed a more significant effect on the ash sintering temperature than the sawdust. The limitation of contents in the fuel blends should be 15% and 50% for straw and sawdust, respectively. SEM analysis indicated that biomass promoted ash deposition by accelerating the formation of neck between ash particles. Transformations of the mineral matter to lower sintering temperatures during co-firing had occurred. - Highlights: • We studied the impact of biomass types and content on ash sintering from co-firing. • The relationship between ash sintering temperature and B:A ratio was established. • The introduction of biomass promoted the ash sintering behavior. • We studied the law for transformation of elemental compositions during co-firing. • Coal–biomass blends should be limited to 15% for straw and 50% for sawdust

  18. Chemical, microbial and physical properties of manufactured soils produced by co-composting municipal green waste with coal fly ash.

    Science.gov (United States)

    Belyaeva, O N; Haynes, R J

    2009-11-01

    Increasing proportions of coal fly ash were co-composted with municipal green waste to produce manufactured soil for landscaping use. Only the 100% green waste treatment reached a thermophilic composting phase (50 degrees C) which lasted for 6 days. The 25% and 50% ash treatments reached 36-38 degrees C over the same period while little or no self-heating occurred in the 75% and 100% ash treatments. Composted green waste had a low bulk density and high total and macro-porosity. Addition of 25% ash to green waste resulted in a 75% increase in available water holding capacity. As the proportions of added ash in the composts increased, the organic C, soluble C, microbial biomass C, basal respiration and activities of beta-glucosidase, L-asparaginase, alkali phosphatase and arylsulphatase enzymes in the composted products all decreased. It could be concluded that addition of fly ash to green waste at a proportion higher than 25% did not improve the quality parameters of manufactured soil. PMID:19539464

  19. Chemical, microbial and physical properties of manufactured soils produced by co-composting municipal green waste with coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Belyaeva, O.N.; Haynes, R.J. [University of Queensland, St Lucia, Qld. (Australia)

    2009-11-15

    Increasing proportions of coal fly ash were co-composted with municipal green waste to produce manufactured soil for landscaping use. Only the 100% green waste treatment reached a thermophilic composting phase ({ge} 50{sup o}C) which lasted for 6 days. The 25% and 50% ash treatments reached 36-38{sup o}C over the same period while little or no self-heating occurred in the 75% and 100% ash treatments. Composted green waste had a low bulk density and high total and macro-porosity. Addition of 25% ash to green waste resulted in a 75% increase in available water holding capacity. As the proportions of added ash in the composts increased, the organic C, soluble C, microbial biomass C, basal respiration and activities of beta-glucosidase, L-asparaginase, alkali phosphatase and arylsulphatase enzymes in the composted products all decreased. It could be concluded that addition of fly ash to green waste at a proportion higher than 25% did not improve the quality parameters of manufactured soil.

  20. The evaluation of geopolymer properties prepared by alkali activation of black coal ashes with high content of loss on ignition

    Directory of Open Access Journals (Sweden)

    Michalíková Františka

    2010-11-01

    Full Text Available The utilization of fly ashes in Slovakia is lower than in other countries and dumping of fly ashes prevails. The dumping changeschemical and phase composition of fly ashes and so it decreases possibilities for their utilization. Fly ashes are mainly used in buildingindustry, where the content of loss on ignition (LOI is limited due to standards. Black coal fly ashes produced in Slovakia have a highcontent of loss on ignition – more than 20 % - so they straight utilization in building industry is not possible. The current possibility fortheir utilization is in geopolymer synthesis. Products with 28-day compression strength of 35.7 MPa and 180-day compression strengthof 55.0 MPa were obtained by alkali activation of fly ashes with 23.25 % LOI with 8 wt% Na2O and their next hardening in temperatureof 80 °C during 6 hours. Products have a great frost-resistance and aggressive environments resistance (NaCl a H2SO4 solutions.

  1. The evaluation of geopolymer properties prepared by alkali activation of black coal ashes with high content of loss on ignition

    International Nuclear Information System (INIS)

    The utilization of fly ashes in Slovakia is lower than in other countries and dumping of fly ashes prevails. The dumping changes chemical and phase composition of fly ashes and so it decreases possibilities for their utilization. Fly ashes are mainly used in building industry, where the content of loss on ignition (LOI) is limited due to standards. Black coal fly ashes produced in Slovakia have a high content of loss on ignition - more than 20 % - so they straight utilization in building industry is not possible. The current possibility for their utilization is in geopolymer synthesis. Products with 28-day compression strength of 35.7 MPa and 180-day compression strength of 55.0 MPa were obtained by alkali activation of fly ashes with 23.25 % LOI with 8 wt % Na2O and their next hardening in temperature of 80 grad C during 6 hours. Products have a great frost-resistance and aggressive environments resistance (NaCl a H2SO4 solutions). (authors)

  2. Full-scale ash deposition measurements at Avedøre Power Plant unit 2 during suspension-firing of wood with and without coal ash addition

    DEFF Research Database (Denmark)

    Wu, Hao; Shafique Bashir, Muhammad; Jensen, Peter Arendt

    2012-01-01

    The formation of deposits during suspension-firing of wood at Avedøre Power Plant unit 2 (AVV2) was studied by using an advanced deposit probe system. The tests were conducted both with and without coal ash addition, and at two different locations with flue gas temperatures of 1250-1300 oC and 750-800 oC respectively. The deposit formation process was studied quantitatively though the mass uptake data from the load-cell of the probe, while camera pictures were used to qualitatively verify the ob...

  3. Coal fly ash-containing sprayed mortar for passive fire protection of steel sections

    Directory of Open Access Journals (Sweden)

    Vilches, L. F.

    2005-09-01

    Full Text Available The present article addresses the possible use of coal fly ash as the chief component of sprayed mortars to fireproof steel structures. A pilot wet-mix gunning rig was specifically designed and built to spray different pastes on to sheet steel and sections with different surface/volume ratios. After gunning, the specimens were placed in a furnace and subjected to standard fire resistance testing. Product fire resistance was calculated from the test results. The mortar used in this study, with a high fly ash content, was found to have acceptable mechanical properties as well as afire resistance potential comparable to those of commercial passive fire protection products.

    En este artículo se estudia el posible uso de las cenizas volantes procedentes de la combustión del carbón como constituyente principal de morteros que pueden ser proyectados sobre estructuras metálicas, para protegerlas contra el fuego. Con objeto de estudiar el proceso de proyección, se ha construido una planta piloto de gunitado por vía húmeda. La pasta se ha proyectado sobre placas metálicas y perfiles metálicos con diferentes relaciones superficie/volumen. Tras el gunitado, las probetas proyectadas se colocan en un horno y se someten a un programa de calentamiento según la norma de resistencia al fuego. A partir de los datos obtenidos se ha podido realizar una estimación de la resistencia al fuego del producto. Los resultados muestran que el material proyectado usado en este estudio, que contiene una alta proporción de cenizas volantes, tiene unas propiedades mecánicas aceptables y unas características potenciales de resistencia al fuego comparables a las de otros productos comerciales utilizados en la protección pasiva contra el fuego.

  4. Weathering behaviour of overburden-coal ash blending in relation to overburden management for acid mine drainage prevention in coal surface mine

    International Nuclear Information System (INIS)

    Potentially acid forming (PAF) materials are encapsulated with non-acid forming materials (NAF) in order to prevent acid mine drainage (AMD) in surface coal mines. NAF compaction techniques with fly and bottom ashes from coal-fired power plants are used in mines with limited amounts of NAF materials. This study investigated the weathering behaviour of blended overburden and coal combustion ash in laboratory conditions. Free draining column leach tests were conducted on different blending schemes. The weathering process was simulated by spraying the samples with de-ionized water once per day. The leachates were then analyzed using X-ray diffraction and fluorescence analyses in order to identify the mineral composition of the samples over a 14 week period. Results of the study indicated that the weathering process plays a significant role in controlling infiltration rates, and may increase the capability of capping materials to prevent infiltration into PAF materials. Fly- and bottom-ash additions improved the performance of the encapsulation materials. 3 refs., 4 tabs., 2 figs.

  5. Reuse of ash coal in the formulation of mortars; Reaproveitamento de cinzas de carvao mineral na formulacao de argamassas

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, J.S.; Souza, C.A.G.; Souza, J.A.S., E-mail: jacilene_s@yahoo.com.br, E-mail: celioag@ufpa.br, E-mail: jass@ufpa.br [Programa de Pos Graduacao em Engenharia Quimica, Universidade Federal do Para, UFPA/PPEQ, Belem, PA (Brazil)

    2012-04-15

    This paper aims to study the ash incorporation from the combustion of coal in fluidized bed boilers, in production of mortar, replacing part of cement. Specimens were prepared using Portland cement to the specifications CPII-E-32 of normal characteristics and classification of sand below 100 mesh. Blends in the 4:1 ratio, that is, 4 parts of aggregate to 1 part of cement, with insertion of ashes in the proportions 0, 10, 20, 30, 40 and 50%. The mortar was developed in mixing and casting was made in a mold of 5 cm x 10 cm. The behavior of compressive strength was evaluated after 28 days; the strength decreases with increasing percentage of ash. Additional analysis was carried out by X-ray diffraction, and it was found that the substitution of this waste can be successfully used in mortars with blends of up to 30%. (author)

  6. Possibilities of utilization of fly ash from the black coal Power Engineering of the U. S. Steel Košice

    Directory of Open Access Journals (Sweden)

    Františka Michalíková

    2005-11-01

    Full Text Available The paper presents modes of a direct utilization of the fly ash by-product of the combustion of black power coal in the slag - bottom boilers of the Division Plant Power Engineering ( DP PE of the U. S. Steel Košice ( next USSK . The properties of fly ash limit its use in metallurgy and foundry industry. The fly ash is directly utilizable in the metallurgical industry as a component of powder cover mixtures and insulation inserts, heat insulation parts and exothermical mixtures. The most important components in the mixtures are light micro spheres – cenospheres and heavy micro spheres – plerospheres. The micro spheres significantly improve properties of the powder cover mixtures.

  7. Multielement determination of Chinese standard reference material - coal fly-ash by mono-standard neutron activation analysis

    International Nuclear Information System (INIS)

    Mono-standard neutron activation analysis (MS-NAA) is applied to the determination of 23 elements (Ag, Al, As, Ba, Ce, Co, Cr, Cs, Fe, Hf, K, La, Mg, Mn, Na, Rb, Sb, Sm, Sr, Ta, Ti, V and Yb) in Chinese Standard Reference Material-Coal Fly-Ash. The accuracy of the MS-NAA procedure is checked by analyzing the U.S. NBS Standard Reference Materials: Coal (SRM-1632a), Urgan Particulate (SRM-1648), Orchard Leaves (SRM-1571) and Italy Reference Material Mail Air Dust

  8. The determination of natural radioactive elements U, Th and other main, trace elements in coal and fly ash of sixty one coal-fired plants in China by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    The majority of power plants in China are coal-fired power plants. It is important to determine the natural radioactive elements and main, trace elements in coal and its combustion products for the appreciation of the environmental effects of the burning of coal and for the comprehensive utilization of fly ash as renewable resource. The natural radioactive elements U, Th and thirty six main, trace elements in coal and fly ash of sixty one coal-fired plants in China are determined by INAA using monostandard method. Au, Co and Au, Mn are chosen as neutron flux monitor for long time irradiation and short time irradiation respectively. Results for SRM 1632a (coal) and SRM 1633a (fly ash) agree well with the certified value of NBS. Some use of analysis results are introduced. (author)

  9. The Impact of Coal Combustion Fly Ash Used as a Supplemental Cementitious Material on the Leaching of Constituents from Cements and Concretes

    Science.gov (United States)

    The objective of this report is to compare the leaching of portland cement-based materials that have been prepared with and without coal combustion fly ash to illustrate whether there is evidence that the use of fly ash in cement and concrete products may result in increased leac...

  10. Analysis of coal fly ash by k0-based internal monostandard neutron activation analysis (IM-NAA)

    International Nuclear Information System (INIS)

    Two Coal Fly Ash samples (CFA) were analyzed by k0-based internal mono standard neutron activation analysis (IM-NAA) method utilizing in-situ relative detection efficiency. The relative concentration of the elements present in the CFA samples were determined by IM-NAA with respect to scandium. The fitted insitu relative detection efficiency ratio was in good agreement with the measured ratio and it was within ±4%. The IM-NAA method was validated by analyzing IAEA reference materials (RMs)1633b coal fly ash and 1646? Estuarine Sediment. The ?-score values at 95% confidence level for most of the elements in RMs were within ±2 and the % deviations for the elements determined by IM-NAA method with the certified values for RMs were within 8%, validates the IM-NAA method. (author)

  11. Gypsum amendment to soil can reduce selenium uptake by alfalfa grown in the presence of coal fly ash

    International Nuclear Information System (INIS)

    Experiments in the field and greenhouse were conducted in the presence of coal fly ash to determine whether gypsum can reduce Se concentration in alfalfa (Medicago sativa L.). In the field experiment, conducted at a coal fly ash landfill, 11.2 t ha-1 gypsum was applied to soil as a top dressing to test the effect of gypsum in reducing selenium (Se) concentration in aboveground plant tissue. There were four treatment combinations of gypsum over a two year period, 1990, and 1991: (0, 0), (0, 11.2) (11.2, 0) and (11.2, 11.2). In 1991, the Se concentration was lower in alfalfa grown with gypsum, regardless of whether the gypsum was applied in both years or in only one year, indicating that the effect of gypsum application in the first year persisted into the second year. Since there was no increase in aboveground biomass with added gypsum, differences in Se concentration reflect a competitive interaction between S and Se. In the greenhouse experiment, 12 soil treatments were tested: three levels of fly ash (0, 10 and 20%) in combination with each of four levels of gypsum (0, 2.5, 5 and 7.5%). The Se concentration in alfalfa grown in 10% fly ash declined linearly with increasing gypsum dose, resulting in a reduction in Se concentration of 0.04 ± 0.02 ?g g-1 for each 1% gypsum added for the first harvest and 0.06 ± 0.03 ?g g-1 for each 1% gypsum added in the second harvest. Based on these results, gypsum may prove useful as a management tool to reduce the uptake of Se by plants growing on coal fly ash landfills

  12. Arsenic remediation of drinking water using iron-oxide coated coal bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    MATHIEU, JOHANNA L.; GADGIL, ASHOK J.; ADDY, SUSAN E.A.; KOWOLIK, KRISTIN

    2010-06-01

    We describe laboratory and field results of a novel arsenic removal adsorbent called 'Arsenic Removal Using Bottom Ash' (ARUBA). ARUBA is prepared by coating particles of coal bottom ash, a waste material from coal fired power plants, with iron (hydr)oxide. The coating process is simple and conducted at room temperature and atmospheric pressure. Material costs for ARUBA are estimated to be low (~;;$0.08 per kg) and arsenic remediation with ARUBA has the potential to be affordable to resource-constrained communities. ARUBA is used for removing arsenic via a dispersal-and-removal process, and we envision that ARUBA would be used in community-scale water treatment centers. We show that ARUBA is able to reduce arsenic concentrations in contaminated Bangladesh groundwater to below the Bangladesh standard of 50 ppb. Using the Langmuir isotherm (R2 = 0.77) ARUBA's adsorption capacity in treating real groundwater is 2.6x10-6 mol/g (0.20 mg/g). Time-to-90percent (defined as the time interval for ARUBA to remove 90percent of the total amount of arsenic that is removed at equilibrium) is less than one hour. Reaction rates (pseudo-second-order kinetic model, R2>_ 0.99) increase from 2.4x105 to 7.2x105 g mol-1 min-1 as the groundwater arsenic concentration decreases from 560 to 170 ppb. We show that ARUBA's arsenic adsorption density (AAD), defined as the milligrams of arsenic removed at equilibrium per gram of ARUBA added, is linearly dependent on the initial arsenic concentration of the groundwater sample, for initial arsenic concentrations of up to 1600 ppb and an ARUBA dose of 4.0 g/L. This makes it easy to determine the amount of ARUBA required to treat a groundwater source when its arsenic concentration is known and less than 1600 ppb. Storing contaminated groundwater for two to three days before treatment is seen to significantly increase ARUBA's AAD. ARUBA can be separated from treated water by coagulation and clarification, which is expected to be less expensive than filtration of micron-scale particles, further contributing to the affordability of a community-scale water treatment center.

  13. Hard Coal Fly Ash and Silica-Effect of Fine Particulate Matter Deposits on Brassica chinensis

    Directory of Open Access Journals (Sweden)

    Christian Ulrichs

    2009-01-01

    Full Text Available Problem statement: One focus in recent atmospheric pollution research is on fine Particle Matter (PM, especially as result of increasing traffic and anthropogenic activity in urban areas. Here, the impact on animal and human health has been in the center of many studies. Despite the fact that PM depositions can affect plants on the long term, there are only few studies about the impact on plants conducted. Approach: Therefore we studied the impact of PM on plants, using naturally occurring silica dusts (diatomaceous earth and hard Coal Fly Ash (CFA from burning processes. Dusts were applied onto Brassica chinensis L. using a simple duster (covering upper leaf surfaces or electrostatically (covering leaf upper and -underside. Results: Main components of the tested CFA are SO42-, K, Ca and NH4+. The pH value of eluates was found to be around 9.5 in CFA and 5.7 in silica. B. chinensis was insensitive towards the high pH and showed no growth reduction when grown in silica or CFA substrate. PM deposition on leaf surfaces results through shading in a reduced photosynthetic activity. The reduction is relatively higher at higher light intensities. Photosynthesis stays reduced after removal of silica PM from leaf surfaces. We assume that stomata get cloaked by small particles and that silica absorbs lipids from the epicuticle resulting in a general stress reaction. Smaller sized silica particles resulted in a higher reduction of CO2-absorption. Next to particle size is the photosynthesis negatively correlated with exposure time for silica PM. The chlorophyll fluorescence data indicate that dust-covered leaves exhibited significantly lower quantum yield of PS II and a reduced quantum efficiency of PS II and therefore supported the gas exchange data. Conclusion: Reduced photosynthetic performance would be expected to reduce growth and productivity of B. chinensis. In contrast to silica hard coal fly ash showed only a reduction of photosynthesis through shading but did not have any long time effects after washing them off.

  14. OPTIMISATION OF COPPER AND ZINC IONS REMOVAL FROM AQUEOUS SOLUTION BY COAL FLY ASH AS AN ADSORBENT

    OpenAIRE

    MOYO ,M; MUGUNI, L; NYAMUNDA, B.C

    2012-01-01

    Rapid urbanization and industrialization of our world has led to accumulation of enormous number of contaminants in our environment. Heavy metal ions hold a superlative position in that list and are responsible for contaminating soil, air and water in many parts of the world. Adsorption technology is emerging as a sustainable effective solution. The possibility of using Coal fly ash as an alternative adsorbent for divalent metal ions (Zn2+, Cu2+) removal from simulated solutions was studied. ...

  15. Immobilization of Heavy Metals in Polluted Soils by the Addition of Zeolitic Material Synthesized from Coal Fly Ash.

    OpenAIRE

    Moreno, Natalia; Querol, Xavier; Alastuey, Andrés; García-Sánchez, A.; López Soler, Ángel; Ayora, Carles

    2001-01-01

    The use of zeolitic material synthesized from coal fly ash for the immobilization of pollutants in contaminated soils was investigated in experimental fields at the Doñana toxic spill (South of Spain). This area was flooded with a high heavy metal pyrite slurry in April 1998. Although reclamation activities were carried out very fast, a residual pyrite slurry mixed with soil accounted for relatively high leachable levels of potentially toxic elements such as Zn, Pb, As, Cu, Sb,...

  16. OPTIMISATION OF COPPER AND ZINC IONS REMOVAL FROM AQUEOUS SOLUTION BY COAL FLY ASH AS AN ADSORBENT

    Directory of Open Access Journals (Sweden)

    MOYO ,M

    2012-04-01

    Full Text Available Rapid urbanization and industrialization of our world has led to accumulation of enormous number of contaminants in our environment. Heavy metal ions hold a superlative position in that list and are responsible for contaminating soil, air and water in many parts of the world. Adsorption technology is emerging as a sustainable effective solution. The possibility of using Coal fly ash as an alternative adsorbent for divalent metal ions (Zn2+, Cu2+ removal from simulated solutions was studied. The coal fly ash was characterised by Brunauer Emmet Teller (BET, X-ray diffraction (XRD, X-ray Fluorescence Spectroscopy (XRF and Fourier transforminfrared (FT-IR. Optimum adsorption conditions were determined as a function of pH, adsorbent dosage and contact time for Zn2+ and Cu2+ removal. The adsorption of metal ions was found to be pH dependant.Equilibrium data fitted well to the Freundlich model with R2 values as 0.9932, 0.9971 for Cu2+, Zn2+, respectively. The study showed that disposed coal fly ash could be used as an efficient adsorbent material for the removal of metal ions from aqueous solution.

  17. Formation process of Na-X zeolites from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, H.; Matsumura, S.; Hino, R. [Shimane University, Shimane (Japan). Faculty of Science & Engineering

    2004-03-01

    In order to synthesize Na-X zeolite from coal fly ash (Fa), Fa was pretreated under stirring condition at various temperatures of 20-50{sup o}C for 72 h and then aged at 85{sup o}C for a given period with NaOH solutions. The resulting materials were characterized by various means. When Fa was aged for 72 h without pretreatment, species P were formed. As the pretreating temperature raised from 20 to 50{sup o}C, the degree of crystallinity of faujasite increased, while that of species P decreased. The faujasite species formed was identified as Na-X zeolite with molar ratio SiO{sub 2}/Al{sub 2}O{sub 3} = 2.4. When Fa was pretreated at 50{sup o}C and aged for 60 h, the only species formed was Na-X zeolite. Increasing the pretreating temperature up to 50{sup o}C results in the increase of Si{sup 4+} and Al{sup 3+} concentrations in the treating solution by dissolution of amorphous material in Fa. With the conditions used, the crystalline phase, such as alpha-quartz and mullite, was poorly dissolved during the treatment. Hence, the higher pretreating temperature would give the uniform nucleation and crystal growth of Na-X zeolite during the aging.

  18. Synthesis of Zeolite from Coal Fly Ash: Its Application as Water Sorbent

    Directory of Open Access Journals (Sweden)

    Prasert Pavasant

    2010-03-01

    Full Text Available Coal fly ash (CFA was used as raw material for zeolite synthesis by fusion method. In detail, it was mixed with NaOH (with ratio of 2.25 and treated under various temperatures. Synthesized zeolite was characterized using various techniques i.e. X-rayfluorescence (XRF, X-ray diffraction (XRD, and BET surface area analysis. It was found that the surface area of synthesized zeolite were in the range of 49.407-69.136 m2/g depending on the preparing condition, compared to the surface area of CFA about 17.163 m2/g. In addition, according to the XRD result, it was proven that the form of zeolite was Sodium Aluminum Silicate Hydrate (1.08Na2O.Al2O3.1.68SiO2.1.8H2O. The synthesized zeolite was then applied as water sorbent to remove water from ethanol solution (95%. The testing results revealed that the optimal fusion temperature was 450.C, which provided maximum percentage of water removal from ethanol solution (from 95% ethanol to 99.25% ethanol. For comparison, commercial-grade molecular sieve was also tested and was found to increase ethanol concentration from 95% to 99.61%. Hence, it is concluded that our synthesized zeolite provides comparable performance to the commercial-grade molecular sieve.

  19. Coal fly ash supported nZnO for the sorption of triphenyltin chloride/

    Directory of Open Access Journals (Sweden)

    Ayanda Olushola S.

    2015-03-01

    Full Text Available A laboratory study was performed to study the effects of various operating factors, viz. adsorbent dose, contact time, solution pH, stirring speed, initial concentration and temperature on the adsorption of triphenyltin chloride (TPT onto coal fly ash supported nZnO (CFAZ. The adsorption capacity increases with increase in the adsorbent amount, contact time, pH, stirring speed and initial TPT concentration, and decrease with increase in the solution temperature. The adsorption data have been analyzed by Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R adsorption models to determine the mechanistic parameters associated with the adsorption process while the kinetic data were analyzed by pseudo first-order, pseudo second-order, Elovich, fractional power and intraparticle diffusivity kinetic models. The thermodynamic parameters of the process were also determined. The results of this study show that 0.5 g of CFAZ was able to remove up to 99.60% of TPT from contaminated natural seawater at 60 min contact time, stirring speed of 200 rpm and at a pH of 8. It was also found that the equilibrium and kinetic data fitted better to Freundlich and pseudo second-order models, respectively. It can therefore be concluded that CFAZ can be effectively used for shipyard process wastewater treatment

  20. Natural radioactivity of coal and fly ash at the Nikola Tesla B TPP

    OpenAIRE

    Kisi? Dragica M.; Mileti? Saša R.; Radonji? Vladimir D.; Radanovi? Sanja B.; Filipovic Jelena Z.; Gržeti? Ivan A.

    2013-01-01

    Serbian thermal power plants (TPPs) produce siliceous fly ash from lignite in the quantity of approximately 6 million tons per year. The potential market for the use of fly ash is operational, but for the time being, only used by cement producers. Fly ash radioactivity could be one of the major points of concern when larger use of fly ash is planned, particularly in the Serbian construction industry. Radioactivity measurements have been conducted regularly ...

  1. Co-combustion of pulverized coal and solid recovered fuel in an entrained flow reactor- General combustion and ash behavior

    DEFF Research Database (Denmark)

    Wu, Hao; Glarborg, Peter

    2011-01-01

    Co-combustion of a bituminous coal and a solid recovered fuel (SRF) was carried out in an entrained flow reactor, and the influence of additives such as NaCl, PVC, ammonium sulphate, and kaolinite on co-combustion was investigated. The co-combustion experiments were carried out with SRF shares of 7.9 wt.%, 14.8 wt.% and 25 wt.%, respectively. The effect of additives was evaluated by maintaining the share of secondary fuel (mixture of SRF and additive) at 14.8 wt.%. The experimental results showed that the fuel burnout, NO and SO2 emission in co-combustion of coal and SRF were decreased with increasing share of SRF. The majority of the additives inhibited the burnout, except for NaCl which seemed to have a promoting effect. The impact of additives on NO emission was mostly insignificant, except for ammonium sulphate which greatly reduced the NO emission. For SO2 emission, it was found that all of the additives increased the S-retention in ash. Analysis of the bulk composition of fly ash from different experiments indicated that the majority of S and Cl in the fuels were released to gas phase during combustion, whereas the K and Na in the fuels were mainly retained in ash. When co-firing coal and SRF, approximately 99 wt.% of the K and Na in fly ash was present in water insoluble form such as aluminosilicates or silicates. The addition of NaCl, PVC, and ammonium sulphate generally promoted the vaporization of Na and K, resulting in an increased formation of water soluble alkalis such as alkali chlorides or sulphates. The vaporization degree of Na and K was found to be correlated during the experiments, suggesting an interaction between the vaporization of Na and K during pulverized fuel combustion. By collecting deposits on an air-cooled probe during the experiments, it was found that the ash deposition propensity in co-combustion was decreased with increasing share of SRF. The addition of NaCl and PVC significantly increased the ash deposition propensity, whereas the addition of ammonium sulphate or kaolinite showed a slight reducing effect. The chlorine content in the deposits generally implied a low corrosion potential during co-combustion of coal and SRF, except for the experiments with NaCl or PVC addition.

  2. Report of base consolidation promotion survey of overseas coal import in FY 1993. Feasibility survey of effective utilization of coal ash; 1993 nendo kaigaitan yunyu kiban seibi sokushin chosa. Sekitanbai yuko riyo jigyo no feasibility chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    This report describes the effective utilization of coal ash discharged from general industry (general industry ash) as improving material of construction waste soil and deodorant for poultry industry. Coal ash is characterized by the pozzolan and self-hardening properties which are not shown in soil and sand. Coal ash having a large amount of free CaO in its composition has stronger such properties. Coal ash generated from fluidized bed combustor which is a kind of combustor of coal contains a large amount of free CaO, especially, resulting in the stronger such properties. On the other hand, coal ash has water and oil absorbing property due to its porous structure. To utilize these properties, the improving material of soft construction waste soil and deodorant for poultry industry have been selected. As a result of laboratory and field tests for the former, it was found that sufficient supporting force can be obtained. Since the protection of powder splash is required at the site, a humidification system has been developed, which can protect the splash by the humidification of 5%. The price between 500 and 1,000 yen/ton is suitable for the improving material of construction waste soil. The maximum price of the deodorant for poultry industry is 10 yen/kg. 14 refs., 40 figs., 49 tabs.

  3. The leaching behaviour and geochemical fractionation of trace elements in hydraulically disposed weathered coal fly ash.

    Science.gov (United States)

    Nyale, Sammy M; Eze, Chuks P; Akinyeye, Richard O; Gitari, Wilson M; Akinyemi, Segun A; Fatoba, Olanrewaju O; Petrik, Leslie F

    2014-01-01

    A five-step sequential extraction (SE) procedure was used to investigate the leaching behaviour and geochemical partitioning of the trace elements As, Zn, Pb, Ni, Mo, Cr and Cu in a 20-year-old fly ash (FA) dump. The weathered FA, which was hydraulically co-disposed with salt laden brine in slurry form (FA: brine ratio of 1:5), was analyzed and compared with fresh FA. The weathered FA samples were collected from three cores, drilled at a coal-fired power station in the Republic of South Africa while the fresh FA sample was collected from the hoppers in the ash collection system at the power station. The FA samples were sequentially leached using: ultrapure water; ammonium acetate buffer solution (pH 7); ammonium acetate buffer solution (pH 5); hydroxylamine hydrochloride in nitric acid (pH 2) and finally the residues were digested using a combination of HClO4: HF: HNO3 acids. Digestion of as received (unleached) FA samples was also done using a combination of HClO4: HF: HNO3 acids in order to determine the total metal content. The trace element analysis was done using ICP-OES (Varian 710-ES). The SE procedure revealed that the trace elements present in the fresh FA and the weathered FA samples obtained from the three cores could leach upon exposure to different environmental conditions. The trace elements showed continuous partitioning between five geochemical phases i.e., water soluble fraction, exchangeable fraction, carbonate fraction, Fe and Mn fraction and residual fraction. Although the highest concentration of the trace elements (ranging 65.51%-86.34%) was contained in the residual fraction, a considerable amount of each trace element (ranging 4.42%-27.43%) was released from the labile phases (water soluble, exchangeable and carbonate fractions), indicating that the trace species readily leach from the dumped FA under environmental conditions thus pose a danger to the receiving environment and to groundwater. PMID:24171424

  4. Microsphere zeolite materials derived from coal fly ash cenospheres as precursors to mineral-like aluminosilicate hosts for {sup 135,137}Cs and {sup 90}Sr

    Energy Technology Data Exchange (ETDEWEB)

    Vereshchagina, Tatiana A., E-mail: tatiana@icct.ru [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, 50/24 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Vereshchagin, Sergei N., E-mail: snv@icct.ru [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, 50/24 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Shishkina, Nina N., E-mail: ninash@icct.ru [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, 50/24 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Vasilieva, Nataly G., E-mail: vng@icct.ru [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, 50/24 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Solovyov, Leonid A., E-mail: leosol@icct.ru [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, 50/24 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Anshits, Alexander G., E-mail: anshits@icct.ru [Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, 50/24 Akademgorodok, Krasnoyarsk 660036 (Russian Federation); Department of Chemistry, Siberian Federal University, 79 Svobodnyi Avenue, Krasnoyarsk 660041 (Russian Federation)

    2013-06-15

    Hollow microsphere zeolite materials with a bilayered zeolite/glass crystalline shell bearing NaP1 zeolite were synthesized by the hydrothermal treatment of coal fly ash cenospheres (Si/Al = 2.7) in an alkaline medium. Cs{sup +} and/or Sr{sup 2+} forms of zeolitized cenospheres with the different Cs{sup +} and/or Sr{sup 2+} loading were prepared by the ion exchange from nitrate solutions. The resulted (Cs,Na)P1, (Sr,Na)P1 and (Cs,Sr,Na)P1 bearing microsphere zeolites were converted to glass ceramics by heating at 900–1000 °C. The differential scanning calorimetry and quantitative phase analysis were used to monitor the solid-phase transformation of the initial and ion exchanged zeolite materials. It was established that the final solidified forms of Cs{sup +} and/or Sr{sup 2+} are glass–crystalline ceramic materials based on pollucite–nepheline, Sr-feldspar–nepheline and Sr-feldspar–pollucite composites including ?60 wt.% of the major host phases (pollucite, Sr-feldspar) and 10–20 wt.% of glass. The {sup 137}Cs leaching rate of 4.1 × 10{sup ?7} g cm{sup ?2} day{sup ?1} was determined for the pollucite glass–ceramic according to Russian State Standard (GOST) No. 52126 P-2003 (7 day, 25 °C, distilled water)

  5. Microsphere zeolite materials derived from coal fly ash cenospheres as precursors to mineral-like aluminosilicate hosts for 135,137Cs and 90Sr

    International Nuclear Information System (INIS)

    Hollow microsphere zeolite materials with a bilayered zeolite/glass crystalline shell bearing NaP1 zeolite were synthesized by the hydrothermal treatment of coal fly ash cenospheres (Si/Al = 2.7) in an alkaline medium. Cs+ and/or Sr2+ forms of zeolitized cenospheres with the different Cs+ and/or Sr2+ loading were prepared by the ion exchange from nitrate solutions. The resulted (Cs,Na)P1, (Sr,Na)P1 and (Cs,Sr,Na)P1 bearing microsphere zeolites were converted to glass ceramics by heating at 900–1000 °C. The differential scanning calorimetry and quantitative phase analysis were used to monitor the solid-phase transformation of the initial and ion exchanged zeolite materials. It was established that the final solidified forms of Cs+ and/or Sr2+ are glass–crystalline ceramic materials based on pollucite–nepheline, Sr-feldspar–nepheline and Sr-feldspar–pollucite composites including ?60 wt.% of the major host phases (pollucite, Sr-feldspar) and 10–20 wt.% of glass. The 137Cs leaching rate of 4.1 × 10?7 g cm?2 day?1 was determined for the pollucite glass–ceramic according to Russian State Standard (GOST) No. 52126 P-2003 (7 day, 25 °C, distilled water)

  6. Synthesis of zeolite from Italian coal fly ash: Differences in crystallization temperature using seawater instead of distilled water

    International Nuclear Information System (INIS)

    In this study Italian coal fly ash was converted into several types of zeolite in laboratory experiments with temperatures of crystallization ranging from 35 up to 90 deg. C. Distilled and seawater were used during the hydrothermal synthesis process in separate experiments, after a pre-treatment fusion with NaOH. The results indicate that zeolites could be formed from different kind of Italian coal fly ash at low temperature of crystallization using both distilled and seawater. SEM data and the powder patterns of X-ray diffraction analysis show that faujasite, zeolite ZK-5 and sodalite were synthesized when using both distilled and seawater; zeolite A crystallized only using distilled water. In particular the experiments indicate that the synthesis of zeolite X and zeolite ZK-5 takes place at lower temperatures when using seawater (35 and 45 deg. C, respectively). The formation of sodalite is always competitive with zeolite X which shows a metastable behaviour at higher temperatures (70-90 deg. C). The chemical composition of the fly ash source could be responsible of the differences on the starting time of synthesized zeolite with distilled water, in any case our data show that the formation of specific zeolites takes place always at lower temperatures when using seawater.

  7. Evaluation of lignin and cellulose contributions to low-rank coal formation by alkaline cupric oxide oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Hayatsu, R.; Botto, R.E.; Scott, R.G.; McBeth, R.L.; Winans, R.E.

    1986-06-01

    Oxidation with alkaline cupric oxide has been combined with solid-state /sup 13/C NMR spectroscopy to evaluate the cellulose and lignin input to the formation of low rank coals. Model studies carried out on lignin-cellulose mixtures, carbonified cellulose, synthetic coals and synthetic humic acids (melanoidins) have established m-hydroxybenzoic acid as a source indicator for cellulose. This product has been found specifically in the oxidation of bio- and geo-macromolecules containing cellulose and/or thermally altered cellulosic material and is chemically distinct from the characteristic oxidation products of lignin-derived materials. Systematic changes in the distribution of the major oxidation products from lignin provide a chemical fingerprint which, in general, can be utilized to trace the thermal history of the sample. Analysis of two lignite coals from the northern hemisphere has demonstrated their predominantly lignitic origin. On the other hand, a Victorian brown coal (pale lithotype) sample is shown to contain a significant amount of highly transformed carbohydrate materials which are presumably incorporated into the macromolecular structure as humic acid derivatives. 36 references.

  8. Restoration of drastically eroded land using coal fly ash and poultry biosolid

    Energy Technology Data Exchange (ETDEWEB)

    Punshon, Tracy; Adriano, Domy C.; Weber, John T. [The University of Georgia, Savannah River Ecology Laboratory, Drawer E 29808 , SC Aiken (United States)

    2002-09-16

    A 3-year field study was conducted at a 12 ha soil-borrow area adjacent to the Columbia Metropolitan Airport, South Carolina to investigate the restorative effects of co-application of coal fly ash (FA) and a poultry biosolid (PB). FA was applied at 0, 22, 280, 560 and 1120 Mg (tonne) ha{sup -1}, and PB at 5 and 10 Mg ha{sup -1}. The area was seeded with erosion-control species Atlantic Coastal panic grass (Panicum amarum var amarum L.), sericea (Lespedeza cuneata var. appalow [Dumont] G. Don.) and weeping love grass (Eragrostis curvula Wolf.). Plant biomass and elemental composition were analyzed in sequential harvests. Soil and groundwater quality characteristics including pH, EC and elemental composition were also monitored throughout the study. In addition, the effect of amendments on the water holding capacity and bulk density of the soil was investigated. Amendment addition significantly increased plant biomass production by a maximum of 26% using 1120 Mg ha{sup -1} FA and 10 Mg ha{sup -1} PB. Application of the highest rate of FA significantly increased the plant tissue concentrations of Mn, As, Se and B. Soil pH was initially increased from 4.6 to 6.1 by amendments. Soil salinity was increased in the initial year only. Amended soils had higher concentrations of Ca, Mg, P and K, higher organic matter content and water holding capacity than unamended soil. Concentrations of plant-essential trace elements (B, Cu and Zn) that were marginally deficient in the unamended eroded soil increased to within typical soil concentrations following amendment with FA and PB. Groundwater quality was unaffected throughout the study. The co-application of FA and PB successfully promoted the revegetation of the eroded borrow area with no apparent adverse environmental side effects.

  9. Potential Use of Malaysian Thermal Power Plants Coal Bottom Ash in Construction

    Directory of Open Access Journals (Sweden)

    Abdulhameed Umar Abubakar

    2012-11-01

    Full Text Available As Malaysia focuses its attention to the call for a “greener” culture, so did the engineers and those in the scientific community especially the construction industry who is a major contributor to the depletion of green house gases. The engineering and construction community has now taken up the challenge for the use of “green and recycled by-products” in construction. One of those by-products is the Coal Bottom Ash (CBA from thermal power plants that faces an increasing production running into hundreds of thousand tonnes in Malaysia alone, and its method of disposal is relegated to landfills alone with no other commercial usage. The construction industry is now forced to rethink on the utilization of the industrial by-products as supplementary materials due to the continuous depletion of natural aggregates in construction. A significant amount of research has been conducted elsewhere on CBA to ascertain its pozzolanic activity, compressive strength in concrete and mortar, durability, water absorption characteristics and density, in order to ensure its usage as a construction material. In this paper, a critical review of the strength characteristics of concrete and mortar as influenced by CBA as partial replacement of fine aggregate is presented based on the available information in the published literatures. Diverse physical and chemical properties of CBA from different power plants in Malaysia are also presented. The influence of different types, amounts and sources of CBA on the strength and bulk density of concrete is discussed. The setting time, workability and consistency as well as the advantages and disadvantages of using CBA in construction materials are also highlighted. An effective utilization of CBA in construction materials will significantly reduce the accumulation of the by-products in landfills and thus reduce environmental pollution.

  10. Coal fly ash as raw material for the manufacture of geopolymer-based products.

    Science.gov (United States)

    Andini, S; Cioffi, R; Colangelo, F; Grieco, T; Montagnaro, F; Santoro, L

    2008-01-01

    In this work coal fly ash has been employed for the synthesis of geopolymers. Two different systems with silica/alumina ratios stoichiometric for the formation of polysialatesiloxo (PSS, SiO2/Al2O3=4) and polysialatedisiloxo (PSDS, SiO2/Al2O3=6) have been prepared. The alkali metal hydroxide (NaOH or KOH) necessary to start polycondensation has been added in the right amount as concentrated aqueous solution to each of the two systems. The concentration of each alkali metal solution has been adjusted in order to have the right liquid volume to ensure constant workability. The systems have been cured at four different temperatures (25, 40, 60, and 85 degrees C) for several different times depending on the temperature (16-672 h at 25 degrees C; 72-336 h at 40 degrees C; 16-120 h at 60 degrees C and 1-6h at 85 degrees C). The products obtained in the different experimental conditions have been submitted to the quantitative determination of the extent of polycondensation through mass increase and loss on ignition, as well as to qualitative characterization by means of FT-IR spectroscopy. Furthermore, physico-structural and mechanical characterization has been carried out through microscopic observations and the determination of unconfined compressive strength, elasticity modulus, apparent density, porosity and specific surface area. The results have indicated that the systems under investigation are suited for the manufacture of pre-formed building blocks at room temperature. PMID:17382528

  11. Properties of geopolymer from circulating fluidized bed combustion coal bottom ash

    International Nuclear Information System (INIS)

    Research highlights: ? Dry cured geopolymers exhibit a heterogeneous and porous gel matrix. ? The Si/Na atomic ratio of the main reaction product (N-A-S-H gel) is close to 1. ? Low Si/Na ratio (0.5) correspond to a more crystalline stage of the N-A-S-H gel. ? N-A-S-H gel has small pores which facilitate the escape of moisture when it is heated. ? N-A-S-H gel became more amorphous, attaining higher Si/Al ratio of 4.54 at 800 deg. C. - Abstract: Compressive strength, atomic ratios and microstructure of geopolymer mortars (GM) made from circulating fluidized bed combustion (CFBC) coal bottom ash (CBA) were investigated to observe the effect of air curing at ambient temperature (AC) at 20 deg. C and 90% RH, dry curing (DC) at 80 deg. C and 40% RH for 20 h. The 28-d compressive strength of GM exposed to AC (GM-AC) and DC (GM-DC) were 26.23 and 24.14 MPa, respectively. The Si/Na atomic ratio of the main reaction product (N-A-S-H gel) was close to 1. Geopolymer gel (apparently crystalline) having low Si/Na ratio (0.5) may correspond to a more advanced or developed stage of the aluminosilicate gel. It was observed that the geopolymerization was completed before the N-A-S-H gel formed when Si/Na ratio of GM is close to 2. The color of the GM changed from pink to grey and the structure became denser with almost no pores, when the temperature increased from 400 to 800 deg. C. The N-A-S-H gel became more amorphous due to the sintering reactions attaining Si/Al and Si/Na ratios of 4.54 and 0.98, respectively.

  12. INFLUENCE OF THE CHEMICAL AND MINERALOGYCAL ASH COMPOSITION OF COAL BLENDS FOR PCI IN THE BEHAVIOR OF FUSIBILITY AND VISCOSITY AT HIGH TEMPERATURES

    Directory of Open Access Journals (Sweden)

    Maria Luisa Formoso Ghigg

    2012-06-01

    Full Text Available Some aspects of permeability deterioration in blast furnace process at high rates of pulverized coal injection are not well known yet. At operational practice variations in the ash quality of injected coals can affect the furnace performance. Previous work has investigated the behavior of individual coals ash at high temperatures in relation to the chemical and mineralogical compositions. This work aimed to assess this behavior for coal blends. Four coals and seven blends were selected and ashed at 800-850°C. The samples were analyzed by X-ray fluorescence and X-ray diffraction techniques and ASTM ash fusion (AFT and viscosity tests were performed. Ash containing high contents of Si and Al showed higher fusion temperatures and higher viscosity at 1500°C, due mainly to the higher content of Mullite and to the low basicity, while those presenting significant contents of Fe, Ca and S had lower fusion temperatures and lower viscosity, due to the higher content of Anorthite and/or to the higher basicity.

  13. Evaluating risks to wildlife from coal fly ash incorporating recent advances in metals and metalloids risk assessment.

    Science.gov (United States)

    Meyer, Carolyn B; Schlekat, Tamar H; Walls, Suzanne J; Iannuzzi, Jacqueline; Souza, Marcy J

    2015-01-01

    Current scientific advances in metal and metalloid risk assessment were applied to evaluate risk to aquatic and riparian wildlife species potentially impacted by residual coal fly ash after cleanup of an unprecedented large ash release into an aquatic environment-the first assessment of its kind. Risk was evaluated using multiple lines of evidence (LOE), including 1) tissue-based risk assessment of inorganic concentrations in piscivorous and insectivorous bird eggs and raccoon organs, 2) deterministic and probabilistic diet-based risk estimates for 10 receptors species, 3) raccoon health metrics, and 4) tree swallow nest productivity measures. Innovative approaches included use of tissue-based toxicity reference values (TRVs), adjustment of bioavailability in the dietary uptake models (using sequential metal extractions in sediment), partitioning chemical species into uptake compartments (e.g., prey gut, nongut, sediment), incorporating uncertainty in both modeled dose and dietary TRVs, matching TRVs to chemical forms of constituents, and pairing these LOEs with reproductive success or health status of sensitive receptor species. The weight of evidence revealed that risk to wildlife from residual ash was low and that risk, though low, was most pronounced for insectivorous birds from exposure to Se and As. This information contributes to the debate surrounding coal combustion residue regulations prompted by this ash release. Because of the responsible party's proactive approach of applying state-of-the-art methods to assess risk using several LOEs that produced consistent results, and because of their inclusion of the regulating agencies in decisions at every step of the process, the risk assessment results were accepted, and an effective approach toward cleanup protective of the environment was quickly implemented. This study highlights the value of using multiple LOEs and the latest scientific advances to assist in timely decision making to obtain an effective remedy for an emergency spill. PMID:25158048

  14. Use of solid waste for chemical stabilization: Adsorption isotherms and {sup 13}C solid-state NMR study of hazardous organic compounds sorbed on coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Netzel, D.A.; Lane, D.C.; Rovani, J.F.; Cox, J.D.; Clark, J.A.; Miknis, F.P.

    1993-09-01

    Adsorption of hazardous organic compounds on the Dave Johnston plant fly ash is described. Fly ash from Dave Johnston and Laramie River power plants were characterized using elemental, x-ray, and {sup 29}Si NMR; the Dave Johnston (DJ) fly ash had higher quartz contents, while the Laramie River fly ash had more monomeric silicate anions. Adsorption data for hydroaromatics and chlorobenzenes indicate that the adsorption capacity of DJ coal fly ash is much less than that of activated carbon by a factor of >3000; but it is needed to confirm that solid-gas and solid-liquid equilibrium isotherms can indeed be compared. However, for pyridine, pentachlorophenol, naphthalene, and 1,1,2,2-tetrachloroethane, the DJ fly ash appears to adsorb these compounds nearly as well as activated carbon. {sup 13}C NMR was used to study the adsorption of hazardous org. cpds on coal fly ash; the nuclear spin relaxation times often were very long, resulting in long experimental times to obtain a spectrum. Using a jumbo probe, low concentrations of some hazardous org. cpds could be detected; for pentachlorophenol adsorbed onto fly ash, the chemical shift of the phenolic carbon was changed. Use of NMR to study the adsorption needs further study.

  15. Comparison of lime and fly ash as amendments to acidic coal mine refusej growth responses and trace-element uptake of two grasses

    Energy Technology Data Exchange (ETDEWEB)

    Jasrow, J. D.; Zimmerman, C. A.; Dvorak, A. J.; Hinchman, R. R.

    1979-10-01

    Two commonly used revegetation species, Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and Lincoln smooth brome (Bromus inermis Leyss.) were grown for 60 days in pots containing coarse coal mine refuse (referred to as gob, pH = 3.5) that was amended with lime or alkaline fly ash. Both species were also grown in pots containing a silt-loam surface soil as a control. Morphological growth parameters were measured over time; dry weights and shoot:root ratios were determined at harvest. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn in the plant shoots were determined by atomic absorption spectrophotometry. Plant growth of both species was not as good on either lime- or fly ash-amended gob as it was on surface soil. Although plant height and length of the longest lead were not significantly different (p > 0.10) at the end of the experiment for plants grown on the two amended-gob substrates, parameters giving an indication of plant vigor (i.e., number of leaves and stems, width of the longest lead, and biomass) were significantly greater (p < 0.01) for plants grown on lime-amended gob than for those grown on fly ash-amended gob. Significant (p < 0.05) differences in the tissue concentrations of Cd, Co, Fe, Hg, Mn, Pb, V, and Zn were found among the plants grown on the three substrates. Except for Hg and Pb, these elements were higher in plants grown on at least one of the amended-gob substrates than in plants grown on surface soil. Significant substrate differences were not observed for Al, As, Cr, Cu, Ni, and Se. The tissue concentrations of some elements - notably Al, Cu, Fe, Mn, V, and Zn - were high enough in plants from one or more of the substrates to either approach or exceed concentrations that have been reported to be associated with toxic effects in some plant species.

  16. Why is Coal Ash of Concern and How to Assess Potential Impacts

    Science.gov (United States)

    EPA's new test methods - the leaching environmental assessment framework (LEAF) are discussed including how they have been used to evaluate fly ash and scrubber residues. Work to evaluate high-volume encapsulated use of fly ash in cementitious material is also described.

  17. Immobilization of chromate from coal fly ash leachate using an attenuating barrier containing zero-valent iron

    DEFF Research Database (Denmark)

    Astrup, Thomas; Stipp, S. L. S.; Christensen, Thomas Højlund

    2000-01-01

    The purpose of this investigation was (i) to test the effectiveness of a barrier engineered to remove Cr(VI) from leachates of higher pH and salinity typical of coal burning ashes and (ii) to determine which geochemical processes control Cr immobilization. Laboratory column and batch desorption experiments show that a barrier composed of sand, Fe(0), and bentonite irreversibly immobilizes Cr. Concentrations fall from 25 mg Cr L-1 in the leachate to below detection limits (0.0025 mg Cr L-1) and s...

  18. Synthesis of zeolite-P from coal fly ash derivative and its utilisation in mine-water remediation

    OpenAIRE

    Leslie F. Petrik; Gillian Balfour; Annabelle Ellendt; Wilson M. Gitari; Viswanath R.K. Vadapalli

    2010-01-01

    Solid residues resulting from the active treatment of acid mine drainage with coal fly ash were successfully converted to zeolite-P under mild hydrothermal treatment conditions. Scanning electron microscopy showed that the zeolite-P product was highly crystalline. The product had a high cation exchange capacity (178.7 meq / 100 g) and surface area (69.1 m2/g) and has potential application in waste-water treatment. A mineralogical analysis of the final product identified...

  19. JV Task 5 - Evaluation of Residual Oil Fly Ash As A Mercury Sorbent For Coal Combustion Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Robert Patton

    2006-12-31

    The mercury adsorption capacity of a residual oil fly ash (ROFA) sample collected form Florida Power and Light Company's Port Everglades Power Plant was evaluated using a bituminous coal combustion flue gas simulator and fixed-bed testing protocol. A size-segregated (>38 {micro}g) fraction of ROFA was ground to a fine powder and brominated to potentially enhance mercury capture. The ROFA and brominated-ROFA were ineffective in capturing or oxidizing the Hg{sup 0} present in a simulated bituminous coal combustion flue gas. In contrast, a commercially available DARCO{reg_sign} FGD initially adsorbed Hg{sup 0} for about an hour and then catalyzed Hg{sup 0} oxidation to produce Hg{sup 2+}. Apparently, the unburned carbon in ROFA needs to be more rigorously activated in order for it to effectively capture and/or oxidize Hg{sup 0}.

  20. Chemical characterization of bottom ashes generated during combustion of a Colombian mineral coal in a thermal power plant

    International Nuclear Information System (INIS)

    Bottom ashes generated during combustion of a mineral coal from Colombia were characterized by X-ray fluorescence spectrometry and X-ray diffraction. The interest in this particular coal is due to the fact that it will be used by a thermal power plant in Ceara, Northeastern Brazil, where it could produce over 900 tons of different residues/combustion products every day. Results from Xray fluorescence allowed identification and quantification of elements present in the sample: silicon (59,17%), aluminum (13,17%), iron (10,74%), potassium (6,11%), titanium (2,91%), calcium (4,97%), sulphur (0,84%) and others (2,09%). The X-ray diffraction revealed patterns from silica, mullite, calcium sulphate and hydrated sodium. Results obtained so far indicate that the material is a potential raw-material for use in the formulation of ceramic components (author)

  1. Natural radioactivity of ground waters and soil in the vicinity of the ash repository of the coal-fired power plant. Nikola Tesla A in Obrenovac, Yugoslavia

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, Z.; Madic, M.; Vukovic, D. [Institute of Nuclear Sciences Vinca, Belgrade (Yugoslavia)

    1996-11-01

    Radioactivity of U, Th and {sup 40}K has been investigated in the vicinity of the ash repository of coal-fired Nikola Tesla A power plant in Obrenovac (Yugoslavia). Using alpha and gamma spectrometry, luminescence spectrophotometry, it was found that the ash repository is a source of radionuclides of the uranium and thorium series; and these radionuclides were found in the ground water up to a distance of several hundred metres. The influence of the repository on the soil radioactivity was minimal.

  2. Mobility and Transport of Inorganic Species in Weathered Hydraulic Disposed Coal Fly Ash: An Insight from Geochemical Fractionation and Statistical Evaluation

    OpenAIRE

    S. A. Akinyemi; O.I. Ojo; W. M. Gitari; A. Akinlua; O. O. Fatoba; L. F. Petrik

    2012-01-01

    A large volume of coal fly ash generated through combustion process has raised environmental concerns due to possible release of potentially toxic species to the surface and groundwater systems. The chemical partitioning and mobility of elements in the hydraulic disposed ash dump was investigated using modified sequential extraction scheme. The geochemical distribution of the investigated elements in 33 drilled core samples was determined by x-ray fluorescence and inductively coupled...

  3. On the pollution of fly coal ashes issued from the thermal power plants

    International Nuclear Information System (INIS)

    Coals in different steps of carbonization for the inorganic mass were investigated using UV-spectroscopy, Instrumental Neutron Activation Analysis and for Uranium the fission fragments track methods. It has been concluded that the toxic and radioactive elements are more concentrated in lower carbonized coals than in higher ones, i.e. pit coals. (Author)

  4. A proposal to evaluate radioactivity of cement containing coal fly ash from China national standard. 'Limits of radionuclides in building materials'

    International Nuclear Information System (INIS)

    This paper is a proposal to evaluate radioactivity of coal fly ash used in cement according the national standard titled 'Limits of radionuclides in building materials'. Because concrete includes cement and nature materials with low radioactivity, we propose that the limits of radionuclides in cement contained coal fly ash can be two times relaxed than that of this national standard, and the limit of the internal exposure index on cement may be unnecessary. There is no obviously increase of the Rn-222 exhalation rate from aerated concrete block when the radium content is similar to that of common concrete block. (author)

  5. Flue gas desulfurization using fly ash alkali derived from Western coals. Final report, July 1975--June 1977

    Energy Technology Data Exchange (ETDEWEB)

    Ness, H.M.; Sondreal, E.A.; Murad, F.Y.; Vig, K.S.

    1977-07-01

    The report gives results of tests investigating the use of Western coal fly ash for scrubbing SO/sub 2/ from power plant flue gas, on a 130-scfm pilot scrubber at the Grand Forks (ND) Energy Research Center and on a 5000-acfm pilot scrubber at the Milton R. Young Generating Station (Center, ND). Tests of the 130-scfm unit were designed to investigate the effects of increased sodium concentration on SO/sub 2/ removal and rate of scaling. Parameters investigated included liquid-to-gas ratios (L/G), stoichiometric ratios (CaO/SO/sub 2/), and sodium concentration. Results indicate increased SO/sub 2/ removal and decreased rate of scaling as sodium concentration increases. Tests of the 5000-acfm unit generated design and operating data for a full-scale 450 MW fly ash alkali scrubber to be constructed at the same Station. Results indicate that sufficient SO/sub 2/ can be removed to meet NSPS requirements, using only fly ash alkali when burning 0.75% sulfur lignite.

  6. Analytical model for erosion behaviour of impacted ?y-ash particles on coal-?red boiler components

    Indian Academy of Sciences (India)

    S K Das; K M Godiwalla; S P Mehrotra; K K M Sastry; P K Dey

    2006-10-01

    Fly ash particles entrained in the ?ue gas from boiler furnaces in coal-?red power stations can cause serious erosive wear on steel surfaces along the ?ow path. Such erosion can signi?cantly reduce the operational life of the boiler components. A mathematical model embodying the mechanisms of erosion on behaviour, has been developed to predict erosion rates of coal-?red boiler components at different temperatures. Various grades of steels used in fabrication of boiler components and published data pertaining to boiler ?y ash have been used for the modelling. The model incorporates high temperature tensile properties of the target metal surface at room and elevated temperatures and has been implemented in an user-interactive in-house computer code (EROSIM–1), to predict the erosion rates of various grades of steel. Predictions have been found to be in good agreement with the published data. The model is calibrated with plant and experimental data generated from a high temperature air-jet erosion-testing facility. It is hoped that the calibrated model will be useful for erosion analysis of boiler components.

  7. Practical use technology of coal ash (Poz-O-Tec); Sekitanbai no yuko riyo gijutsu (POZ-O-TEC)

    Energy Technology Data Exchange (ETDEWEB)

    Konno, K. [Center for Coal Utilization, Japan, Tokyo (Japan); Saito, Y. [Mitsui Mining Co. Ltd., Tokyo (Japan); Nagaya, Y. [Mitsui Construction Co. Ltd., Tokyo (Japan)

    1996-09-01

    In order to utilize more effectively coal ash whose generation amount is increasing year after year, studies have been made on a technology to manufacture and utilize a high-strength substance solidified under normal temperature by utilizing hydration reaction of pozzolan system (Poz-O-Tec). The study works have been done as a subsidy operation of the Agency of Natural Resources and Energy, and were completed in fiscal 1995. Poz-O-Tec is a wet powder made of coal ash and stack gas desulfurization sludge (gypsum) added and mixed with lime and an adequate amount of water, which solidifies by hydration as pozzolan does. The same method as used for ordinary sands may be used as the basic application method. Because this is the material whose strength increases after construction, thickness of construction may be reduced smaller than in constructions using soils and sands. Test constructions of about sixty cases have been carried out to date, typically represented in use as a road bed material, banking, and a base material for water-barrier gutters. High-strength solid material which is stable under normal temperature may be obtained by adjusting calcium content. As a result of its effectiveness in practical use having been verified, a certificate of technological judgment has been issued for the material by the Civil Engineering Research Center. 3 refs., 11 figs., 2 tabs.

  8. Separation of unburned carbon from coal fly ash through froth flotation; Sekitanbai no shisshiki datsutanso gijutsu kaihatsu shiken

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, T. [Center for Coal Utilization, Japan, Tokyo (Japan); Murakami, T. [The Coal Mining Research Center, Japan, Tokyo (Japan)

    1996-09-01

    Coal ash tends to become containing more unburned carbon and porous substances depending on conditions of combustion, whose adverse effects to products due to water adsorbability, absorbability and color tones create obstacles in its utilization. Therefore, research and development works have been progressed on wet type carbon removing technology which is characterized in that coal is pulverized to preferable degrees and subjected to flotation. This paper reports the results obtained during fiscal 1995. The results may be summarized as follows: as a result of the comparison test on a column flotation machine and an FW type flotation machine of machine stirring type, the former machine showed better flotation efficiency; several methods were investigated on crushing as a treatment prior to flotation, whereas a mixer with greater circumferential speed and a homo mixer showed the highest efficiency; strength of the impact to the flotation efficiency was found to decrease in the order of pulp concentration > pretreatment time > collector addition ratio; and as a result of the evaluation on refined ash as a cement admixture and carbons as fuel, possibilities were found in them for practical application. 16 figs., 2 tabs.

  9. NOx removal in SCR process by Cu and Fe exchanged type Y zeolites synthesized from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    M. Teresa Izquierdo; Roberto Juan; A. Isabel Casbas; Begona Rubio; Carmen Ruiz [Instituto de Carboquimica, CSIC, Zaragoza (Spain)

    2009-07-01

    This investigation was undertaken to determine and evaluate the NOx removal capacity of ion-exchanged zeolite Y obtained from Spanish coal fly ash. Coal combustion fly ash was chosen as a source of silicon to prepare zeolite Y following verified procedures, using pure chemicals as a source of aluminium. Zeolite Y was exchanged either with Cu{sup 2+} or Fe{sup 2+} to obtain two different catalysts for the selective catalytic reduction of NOx from flue gas. Zeolite-Fe(II) was transformed into zeolite-Fe(III) by air heating. Materials were exhaustively characterized by chemical analysis, X-ray diffraction, N{sub 2} adsorption and Scanning Electron Microscopy. Zeolitic materials were shaped as monoliths to be tested as SCR catalysts. The SCR experiments in this work were carried out at different operation conditions: temperatures ranging from 50-350{sup o}C and spatial velocity of 1015 h{sup -1}. NO removal capacity of both exchanged zeolites is high, even when water vapour is present in the flue gas. The temperatures needed to reach high NOx conversion are different, depending on the exchanged ion. 16 refs., 8 figs., 2 tabs.

  10. Immobilization of chromate from coal fly ash leachate using an attenuating barrier containing zero-valent iron

    DEFF Research Database (Denmark)

    Astrup, Thomas; Stipp, S. L. S.

    2000-01-01

    The purpose of this investigation was (i) to test the effectiveness of a barrier engineered to remove Cr(VI) from leachates of higher pH and salinity typical of coal burning ashes and (ii) to determine which geochemical processes control Cr immobilization. Laboratory column and batch desorption experiments show that a barrier composed of sand, Fe(0), and bentonite irreversibly immobilizes Cr. Concentrations fall from 25 mg Cr L-1 in the leachate to below detection limits (0.0025 mg Cr L-1) and solution pH increases by about two units. Solid-phase analytical techniques such as SEM, EDS, XPS, and TOFSIMS were used to characterize the barrier material prior to and after exposure to the Cr leachate. In the barrier material, Cr(III) was found associated with Fe(III)-oxides, as separate Cr oxides and as a Ca,Cr phase, probably Cachromite, CaCr2O4. The attenuating barrier can be an alternative to traditional liners and leachate collection systems at coal ash storage and disposal sites.

  11. Removal of sulfuric acid mist from lead-acid battery plants by coal fly ash-based sorbents.

    Science.gov (United States)

    Shu, Yuehong; Wei, Xiangyu; Fang, Yu; Lan, Bingyan; Chen, Hongyu

    2015-04-01

    Sorbents from coal fly ash (CFA) activated by NaOH, CaO and H2O were prepared for H2SO4 mist removal from lead-acid battery plants. The effects of parameters including temperature, time, the ratios of CFA/activator and water/solid during sorbent preparation were investigated. It is found that the synthesized sorbents exhibit much higher removal capacity for H2SO4 mist when compared with that of raw coal fly ash and CaO except for H2O activated sorbent and this sorbent was hence excluded from the study because of its low capacity. The H2SO4 mist removal efficiency increases with the increasing of preparation time length and temperature. In addition, the ratios of CFA/activator and water/solid also impact the removal efficiency, and the optimum preparation conditions are identified as: a water/solid ratio of 10:1 at 120 °C for 10h, a CFA:CaO weight ratio of 10:1, and a NaOH solution concentration of 3 mol/L. The formation of rough surface structure and an increased surface area after NaOH/CaO activation favor the sorption of H2SO4 mist and possible sorption mechanisms might be electrostatic attractions and chemical precipitation between the surface of sorbents and H2SO4 mist. PMID:25603301

  12. Studies of coal ash sintering in lignite combustion; Untersuchungen zum Sinterverhalten von Kohleaschen bei der Braunkohlenverfeuerung

    Energy Technology Data Exchange (ETDEWEB)

    Neuroth, Markus; Schreck, Thomas [RWE Power AG, Niederaussem (Germany). PNR-MM; Simmat, Ralf [Forschungsgemeinschaft Feuerfest e.V., Bonn (Germany); Nover, Georg [Bonn Univ. (Germany). Steinmann Inst.; Mueller, Michael [FZ Juelich (Germany). Inst. fuer Energieforschung IEF2; Muhammadieh, Muhammad [TU Bergakademie Freiberg (Germany); Bonn, Bernhard [FuelConsult GmbH, Essen (Germany)

    2011-07-01

    In a coordinated action of several specialised laboratories a number of different experimental and calculation methods were employed in order to evaluate the sintering temperature of ash from lignites and lignite blends on identical samples. Some of the tested methods have not been employed so far for this purpose and are not yet optimised for measurement on ash samples. In some cases consistent results were obtained which correspond fairly well with experience from boiler operation. (orig.)

  13. A scanning electron microscopy study of ash, char, deposits and fuels from straw combustion and co-combustion of coal and straw

    Energy Technology Data Exchange (ETDEWEB)

    Sund Soerensen, H.

    1998-07-01

    The SEM-study of samples from straw combustion and co-combustion of straw and coal have yielded a reference selection of representative images that will be useful for future comparison. The sample material encompassed potential fuels (wheat straw and grain), bottom ash, fly ash and deposits from straw combustion as well as fuels (coal and wheat straw), chars, bottom ash, fly ash and deposits from straw + coal co-combustion. Additionally, a variety of laboratory ashes were studied. SEM and CCSEM analysis of the samples have given a broad view of the inorganic components of straw and of the distribution of elements between individual ash particles and deposits. The CCSEM technique does, however, not detect dispersed inorganic elements in biomass, so to get a more complete visualization of the distribution of inorganic elements additional analyses must be performed, for example progressive leaching. In contrast, the CCSEM technique is efficient in characterizing the distribution of elements in ash particles and between ash fractions and deposits. The data for bottom ashes and fly ashes have indicated that binding of potassium to silicates occurs to a significant extent. The silicates can either be in the form of alumino-silicates or quartz (in co-combustion) or be present as straw-derived amorphous silica (in straw combustion). This process is important for two reasons. One is that potasium lowers the melting point of silica in the fly ash, potentially leading to troublesome deposits by particle impaction and sticking to heat transfer surfaces. The other is that the reaction between potassium and silica in the bottom ash binds part of the potassium meaning that it is not available for reaction with chlorine or sulphur to form KCl or K{sub 2}SO{sub 4}. Both phases are potentially troublesome because they can condense of surfaces to form a sticky layer onto which fly ash particles can adhere and by inducing corrosion beneath the deposit. It appears that in the studied full-scale experiment of co-combustion of coal and straw, the straw-derived silica were preferentially incorporated in the fly ash relative to the bottom ash. The analyzed deposits from straw-fired CHP's have shown that in the furnace condensation of KCl is important for formation of the initial layer, whereas building of the outer loose part of the deposit is dominated by particle impaction. Additionally, particle impaction is a more prominent process in the furnace compared to what is the case in the superheater region. Potassium was observed to react with sulphur preferentially to chlorine and silicate-compounds during low-temperature (550 deg C) laboratory ashing of a mixture of wheat straw and bituminous coal from MKS3. A similar effect was, however, not observed in full scale fly ashes from MKS3 in which potassium to a high extent have reacted with alumino-silicates to form K-Al silicates. However, potassium sulphates are present in deposits formed during co-combustion at MKS1, especially in the convective pass. (au)

  14. Studying the melting behavior of coal, biomass, and coal/biomass ash using viscosity and heated stage XRD data

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Folkedahl, B.; Dam-Johansen, Kim; Hurley, J.

    2006-01-01

    The use of biomass for power generation can result in significant economical and environmental benefits. The greenhouse emissions can be reduced as well as the cost of the produced electricity. However, ash-related problems, including slagging, agglomeration, and corrosion, can cause frequent unscheduled shutdowns, decreasing the availability and increasing the cost of the produced power. In addition, the fouling of the heat exchange surfaces reduces the system efficiency. In this work the melti...

  15. X-ray powder diffraction-based method for the determination of the glass content and mineralogy of coal (co)-combustion fly ashes

    Energy Technology Data Exchange (ETDEWEB)

    O. Font; N. Moreno; X. Querol; M. Izquierdo; E. Alvarez; S. Diez; J. Elvira; D. Antenucci; H. Nugteren; F. Plana; A. Lopez; P. Coca; F.G. Pena [Institute of Environmental Assessment and Water Research (IDA-CSIC), Barcelona (Spain)

    2010-10-15

    The relevance of Al-Si glass in a number of fly ash applications, such as use as a pozzolanic material, zeolite synthesis, and geopolymer production, necessitated research towards investigation of methods for an easy and consistent determination of the glass content in this coal (co)-combustion by-products. A glass standard-addition X-ray powder diffraction (XRD)-based method is proposed in this study as an alternative to the non straightforward procedure of conventional methods for determining the amorphous components, mainly by difference of the total mass and the addition of quantified crystalline species. A >99% Al-Si glass slag sample was selected as a standard for glass. A number of glass standard/fly ash mixtures were performed on Fluidized Bed Combustion (FBC) and pulverized coal combustion (PCC) fly ashes and subsequently analyzed by XRD. The method provides results closer to quantitative proportions of the Al-Si amorphous material of this (co)-combustion by-product, with a range of values <3% when compared with those obtained by the conventional Reference Intensity Method (RIM) method, demonstrating suitability and consistence of the procedure. The mineralogy of FBC and PCC fly ash was also investigated using the RIM method. The occurrence and proportions of the crystalline components in fly ash are in line with the combustion technology and their inherent operational parameters, especially the (co)-combustion temperature. The FBC fly ash shows the highest content of relic phases from feed coal (quartz, illite, calcite, and feldspars) and lower contents of amorphous components. The PCC fly ash are characterized by the highest proportions of mullite and Al-Si glass and low contents of quartz an other relict phases. The occurrence and distribution of anhydrite and Fe-oxide species appears to be related to the content of Ca and Fe in the feed fuels, showing slightly higher contents in FBC than in PCC fly ash. 26 refs., 3 figs., 5 tabs.

  16. Characteristics of hopanoid hydrocarbons in ambient PM10 and motor vehicle emissions and coal ash in Taiyuan, China.

    Science.gov (United States)

    Han, Feng; Cao, Junji; Peng, Lin; Bai, Huiling; Hu, Dongmei; Mu, Ling; Liu, Xiaofeng

    2015-10-01

    Hopanoid hydrocarbon content in ambient particulate matter (PM) of less than or equal to 10 ?m aerodynamic diameter (PM10) was sampled at seven sites representative of different functional districts, and measured by gas chromatography-mass spectrometry. 17?(H),21?(H)-hopane (C30??) and 17?(H),21?(H)-30-norhopane (C29??) were dominant in all samples. Hopanes in motor vehicle emissions from various fuel-type engines (gasoline, diesel and natural gas) and coal ash were qualitatively measured, and the amount of C30?? was about two to three times greater than that of C29??. Distinct seasonal variations (winter/summer differences) were observed at higher concentrations (45.54-108.29 ng/m(3)) of total hopanes in winter and lower (2.59-28.26 ng/m(3)) in summer. There were also clear spatial variations of hopanes in Taiyuan, with samples with greater hopane concentrations in downtown areas, but less in summer. The spatial distribution reversed in winter. Distributions and relative abundances of selected hopanes from PM10 and source emissions indicated that in summer, vehicle exhaust was the dominant fossil fuel combustion source (C30?? was >C29??), and that the contribution of coal combustion was slightly greater at suburban sites. However, the contribution of coal combustion sources increased significantly at all sites in winter, especially in suburban areas, where C29?? exceeded C30??. Hopanoid indexes revealed a classification of vehicle exhaust and coal combustion emissions in PM10. The results imply that during rapid urbanization, it is crucial to strengthen the construction of infrastructure such as central heating in new city districts and to increase the use of natural gas instead of residential coal burning. PMID:26362677

  17. Relationship between selenium body burdens and tissue concentrations in fish exposed to coal ash at the Tennessee Valley Authority Kingston spill site

    Energy Technology Data Exchange (ETDEWEB)

    Mathews, Teresa J [ORNL; Fortner, Allison M [ORNL; Jett, Robert T [ORNL; Peterson, Mark J [ORNL; Carriker, Neil [Tennessee Valley Authority (TVA); Morris, Jesse G [ORNL; Gable, Jennifer [Environmental Standards, Inc.

    2014-01-01

    In December 2008, 4.1 million m3 of coal ash were released into the Emory and Clinch Rivers by the Tennessee Valley Authority (TVA) Kingston Fossil Plant. Coal ash contains several contaminants, including the bioaccumulative metalloid selenium (Se). Because Se is predominantly accumulated in aquatic organisms through dietary, rather than aqueous exposure, tissue-based toxicity thresholds for Se are currently being considered. The proposed threshold concentrations range between 4-9 g/g Se (dry wt.) in whole body fish, with a proposed fillet threshold of 11.8 g/g. In the present study we examined the spatial and temporal trends in Se bioaccumulation and examined the relationship between the Se content in fillets and in whole bodies of fish collected around the Kingston spill site to determine whether Se bioaccumulation was a significant concern at the ash spill site. While Se concentrations in fish (whole bodies and fillets) were elevated at sampling locations affected by the Kingston ash spill relative to reference locations, concentrations do not appear to be above risk thresholds and have not been increasing over the five year period since the spill. Our results are not only relevant to guiding the human health and ecological risk assessments at the Kingston ash spill site, but because of current national discussions on appropriate guidelines for Se in fish as well for the disposal of coal combustion wastes, our results are also relevant to the general understanding of Se bioaccumulation in contaminated water bodies.

  18. Adsorption of anionic dyes from aqueous solutions onto coal fly ash and zeolite synthesized from coal fly ash; Adsorcao de corantes anionicos de solucao aquoso em cinza leve de carvao e zeolita de cinza leve de carvao

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Terezinha Elizabeth Mendes de

    2010-07-01

    Coal fly ash, a waste generated in coal-fired electric power plant, was used to synthesize zeolite by hydrothermal treatment with NaOH solution. The fly ash (CL-2) and this synthesized zeolite (ZM-2) that was characterized as hydroxy-sodalite were used as adsorbents for anionic dyes indigo carmine (IC), and reactive orange 16 (RO16) from aqueous solutions. Effects of contact time, initial dye concentration, pH, adsorbent mass, and temperature were evaluated in the adsorption processes. The kinetics studies indicated that the adsorption followed the pseudo-second order kinetics and that surface adsorption and intraparticle diffusion were involved in the adsorption mechanism. The thermodynamics parameters demonstrated that the adsorption was spontaneous for all adsorption processes. The enthalpy data confirmed the endothermic nature for all adsorption processes except for IC/ZM-2 system which was exothermic. The entropy data showed an increased disorder at the solid/solution interface during the adsorption for all systems except for IC/ZM-2 whose negative entropy value indicated a decreased disorder at the interface. The adsorption isotherms were closely fitted to the Langmuir linear equation. The maximum adsorption capacities were 1.48 mg/g for the IC/CL-2 system; 1.13 mg/g for IC/ZM-2; 0.96 mg/g for RO16/CL-2, and 1.14 mg/g for RO16/ZM-2 at room temperature. The desorption study carried out with water, with acid aqueous solutions, and with an alkali aqueous solution showed to be inefficient both for recovering the dyes and regenerating the adsorbents. (author)

  19. Experimental investigation into compression properties of integrated coal gasification combined cycle fly ashes on a ceramic filter

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.H.; Bak, Y.C.; Jang, H.J.; Kim, J.F.; Kim, J.H. [Gyeongsang National University, Jinju (Republic of Korea). Dept. of Chemical Engineering & ERI

    2004-05-01

    The compression properties of IGCC (integrated coal gasification combined cycle) fly ash cake on a ceramic filter were carefully investigated under well-controlled conditions. Overall cake porosity and pressure drop of dust cake of three different particles of geometric mean diameters of 3.7, 6.2, and 12.1 {mu}m, and dynamic shape factors of 1.37, 1.57 and 1.65, respectively, were investigated, at face velocities of 0.02-0.06 m/s. Overall cake porosity was strongly dependent on face velocity, mass load, and particle size. The expressions for overall cake porosity, considering the compression effect, and pressure drop across the dust cake were developed with good agreement with experimental results.

  20. Ancillary operations in coal preparation instrumentation on-line low cost sulfur and ash analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Malito, M.L.

    1991-07-01

    The purpose of this document is to define the testing to be performed on field collected coal slurry samples by ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy). A total of 20 samples (8 from an Upper Freeport coal and 12 from an Oklahoma coal) are to be analyzed in triplicate for the elements S, Si, Al, Fe, Ca, and Mg. For each of the two coal slurry types (Upper Freeport and Oklahoma), a container of slurry labeled calibration'' has been prepared. These calibration slurries may be used to get the system tuned'' (note that the volume of the field collected slurries is relatively small and cannot be used to tune'' the system). The calibration slurries were made from the slurry collected from the drain from the second sampling stage during the field testing.

  1. Synthesis of Zeolites Na-P1 from South African Coal Fly Ash: Effect of Impeller Design and Agitation

    Directory of Open Access Journals (Sweden)

    Leslie Petrik

    2013-05-01

    Full Text Available South African fly ash has been shown to be a useful feedstock for the synthesis of some zeolites. The present study focuses on the effect of impeller design and agitation rates on the synthesis of zeolite Na-P1 which are critical to the commercialization of this product. The effects of three impeller designs (4-flat blade, Anchor and Archimedes screw impellers and three agitation speeds (150, 200 and 300 rpm were investigated using a modified previously reported synthesis conditions; 48 hours of ageing at 47 °C and static hydrothermal treatment at 140 °C for 48 hours. The experimental results demonstrated that the phase purity of zeolite Na-P1 was strongly affected by the agitation rate and the type of impeller used during the ageing step of the synthesis process. Although zeolite Na-P1 was synthesized with a space time yield (STY of 15 ± 0.4 kg d?1m?3and a product yield of 0.98±0.05 g zeolites/g fly ash for each impeller at different agitation speeds, zeolite formation was assessed to be fairly unsuccessful in some cases due the occurrence of undissolved mullite and/or the formation of impurities such as hydroxysodalite with the zeolitic product. This study also showed that a high crystalline zeolite Na-P1 can be synthesized from South African coal fly ash using a 4-flat blade impeller at an agitation rate of 200 rpm during the ageing step at 47 °C for 48 hours followed by static hydrothermal treatment at 140 °C for 48 hours.

  2. Cenizas de carbón sedimentadas: su efecto puzolánico en clinker Portland / Sedimental coal ashes: its pozzolanic effects in Portland cement clinker

    Scientific Electronic Library Online (English)

    M.A., Trezza; A.E., Crozes; A.N., Scian.

    Full Text Available Las centrales termoeléctricas generan una gran cantidad de residuos sólidos como producto de la combustión del carbón, conocidos como cenizas. Existen dos tipos de cenizas: volantes - de tamaño muy fino -, que son arrastradas por la corriente de humos de los sistemas de eliminación de partículas y, [...] - las sedimentadas - más gruesas, que se funden y se aglomeran acumulándose en el fondo del horno o en los tubos de las calderas. Intentando resolver factores técnico-económicos y ecológicos al mismo tiempo, en este trabajo presentamos los resultados obtenidos de la incorporación de un 20% en peso de cenizas sedimentadas (Cs) como adición activa al cemento Portland. Se estudia la potencial puzolanidad de la adición y se muestran resultados de seguimiento de la hidratación a temprana edad, variación de color y resistencia mecánica del material compuesto obtenido por molienda conjunta del clinker portland y el material residual. Abstract in english The power plants generate a large amount of solid waste, known as ash, as a product of combustion of coal. There are two types of ash: fly - very fine in size- which are carried by the flow of smoke removal systems, and sedimentary particles -coarse particles - which are melted and agglomerated accu [...] mulated in the bottom of the furnace or in the boiler tubes. Trying to resolve technical-economic and ecologic factors at the same time, this work presents the results of adding a 20% weight of sediment ash (Cs) as an active addition to the Portland cement. The potential pozzolanity of the addition is studied and it is shown proceeding of the hydration at early age, color variation and mechanical strength of the composite material obtained by grinding together Portland clinker with the residual material.

  3. Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents - 1. Hematological and population level assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lohner, T.W.; Reash, R.J.; Willet, V.E.; Rose, L.A. [American Electrical Power Co., Columbus, OH (United States). Environmental Services Dept.

    2001-07-01

    Sunfish were collected from coal ash effluent-receiving streams and Ohio River watershed reference sites to assess the effects of exposure to low-level selenium concentrations. Selenium, copper, and arsenic concentrations were statistically higher in tissue samples from exposed fish than in reference fish. Leukopenia, lymphocytosis, and neutropenia were evident in exposed fish and were indicative of metal exposure and effect. White blood cell counts and percent lymphocyte values were significantly correlated with liver selenium concentrations. Plasma protein levels were significantly lower in exposed fish than in fish from the Ohio River, indicating that exposed fish may have been nutritionally stressed. Condition factors for fish from the ash pond-receiving streams were the same as, or lower than, those of fish from the reference sites. There was no evidence that the growth rate of fish in the receiving streams differed from that of fish in the reference streams. Despite liver selenium concentrations which exceeded reported toxicity thresholds and evidence of significant hematological changes, there were no significant differences in fish condition factors, liver-somatic indices, or length-weight regressions related to selenium.

  4. Synthesis of zeolite-P from coal fly ash derivative and its utilisation in mine-water remediation

    Directory of Open Access Journals (Sweden)

    Leslie F. Petrik

    2010-05-01

    Full Text Available Solid residues resulting from the active treatment of acid mine drainage with coal fly ash were successfully converted to zeolite-P under mild hydrothermal treatment conditions. Scanning electron microscopy showed that the zeolite-P product was highly crystalline. The product had a high cation exchange capacity (178.7 meq / 100 g and surface area (69.1 m2/g and has potential application in waste-water treatment. A mineralogical analysis of the final product identified zeolite-P, as well as mullite and quartz phases, which indicated incomplete dissolution of the fly ash feedstock during the ageing step. Further optimisation of the synthesis conditions would be required to attain complete utilisation of the feedstock. The zeolite-P was tested for decontamination potential of circumneutral mine water. High removal efficiency was observed in the first treatment, but varied for different contaminants. The synthesised zeolite-P exhibited a high efficiency for the removal of heavy metal cations, such as aluminium, iron, manganese, zinc, copper and nickel, from contaminated mine water, even with repeated use. For potassium, calcium, strontium and barium, the removal was only efficient in the first treatment and decreased rapidly with subsequent treatments, indicating preferential adsorption of the other metals. A continuous release of sodium was observed during decontamination experiments, which decreased with subsequent treatments, confirming that sodium was the main exchangeable charge-balancing cation present in the zeolite-P product.

  5. Self-cementitious properties of fly ashes from CFBC boilers co-firing coal and high-sulphur petroleum coke

    International Nuclear Information System (INIS)

    Self-cementitious properties of fly ash from circulating fluidized bed combustion boiler co-firing coal and high-sulphur petroleum coke (CPFA) were investigated. CPFA was self-cementitious which was affected by its fineness and chemical compositions, especially the contents of SO3 and free lime (f-CaO). Higher contents of SO3 and f-CaO were beneficial to self-cementitious strength; the self-cementitious strength increases with a decrease of its 45 ?m sieve residue. The expansive ratio of CPFA hardened paste was high because of generation of ettringite (AFt), which was influenced by its water to binder ratio (W/A), curing style and grinding of the ash. The paste cured in water had the highest expansive ratio, and grinding of CPFA was beneficial to its volume stability. The hydration products of CPFA detected by X-ray diffraction (XRD) and scanning electron microscopy (SEM) were portlandite, gypsum, AFt and hydrated calcium silicate (C-S-H)

  6. Synthesis of zeolite-P from coal fly ash derivative and its utilisation in mine-water remediation

    Scientific Electronic Library Online (English)

    Viswanath R.K., Vadapalli; Wilson M., Gitari; Annabelle, Ellendt; Leslie F., Petrik; Gillian, Balfour.

    2010-06-01

    Full Text Available Solid residues resulting from the active treatment of acid mine drainage with coal fly ash were successfully converted to zeolite-P under mild hydrothermal treatment conditions. Scanning electron microscopy showed that the zeolite-P product was highly crystalline. The product had a high cation excha [...] nge capacity (178.7 meq / 100 g) and surface area (69.1 m²/g) and has potential application in waste-water treatment. A mineralogical analysis of the final product identified zeolite-P, as well as mullite and quartz phases, which indicated incomplete dissolution of the fly ash feedstock during the ageing step. Further optimisation of the synthesis conditions would be required to attain complete utilisation of the feedstock. The zeolite-P was tested for decontamination potential of circumneutral mine water. High removal efficiency was observed in the first treatment, but varied for different contaminants. The synthesised zeolite-P exhibited a high efficiency for the removal of heavy metal cations, such as aluminium, iron, manganese, zinc, copper and nickel, from contaminated mine water, even with repeated use. For potassium, calcium, strontium and barium, the removal was only efficient in the first treatment and decreased rapidly with subsequent treatments, indicating preferential adsorption of the other metals. A continuous release of sodium was observed during decontamination experiments, which decreased with subsequent treatments, confirming that sodium was the main exchangeable charge-balancing cation present in the zeolite-P product.

  7. Ecological risk assessment for residual coal fly ash at Watts Bar Reservoir, Tennessee: Limited alteration of riverine-reservoir benthic invertebrate community following dredging of ash-contaminated sediment.

    Science.gov (United States)

    Buys, David J; Stojak, Amber R; Stiteler, William; Baker, Tyler F

    2015-01-01

    Benthic invertebrate communities were assessed after the December 2008 release of approximately 4.1 million m(3) coal fly ash from a disposal dredge cell at the Tennessee Valley Authority (TVA) Kingston Fossil Plant on Watts Bar Reservoir in Roane County, Tennessee, USA. Released ash filled the adjacent embayments and the main channel of the Emory River, migrating into reaches of the Emory, Clinch, and Tennessee Rivers. Dredging was completed in summer 2010, and the benthic community sampling was conducted in December 2010. This study is part of a series that supported an Ecological Risk Assessment for the Kingston site. Benthic invertebrate communities were sampled at transects spread across approximately 20 miles of river that includes both riverine and reservoirlike conditions. Community composition was assessed on a grab sample and transect basis across multiple cross-channel transects to gain an understanding of the response of the benthic community to a fly ash release of this magnitude. This assessment used invertebrate community metrics, similarity analysis, geospatial statistics, and correlations with sediment chemistry and habitat. The community composition was reflective of a reservoir system, with dominant taxa being insect larva, bivalves, and aquatic worms. Most community metric results were similar for ash-impacted areas and upstream reference areas. Variation in the benthic community was correlated more with habitat than with sediment chemistry or residual ash. Other studies have reported that a benthic community can take several years to a decade to recover from ash or ash-related constituents. Although released ash undoubtedly had some initial impacts on the benthic community in this study, the severity of these effects appears to be limited to the initial smothering of the organisms followed by a rapid response and the initial start of recovery postdredging. PMID:25158124

  8. Utilisation of different types of coal fly ash in the production of ceramic tiles

    Directory of Open Access Journals (Sweden)

    Kockal, N. U.

    2012-10-01

    Full Text Available The influence of varying proportions of different types of fly ash (used in place of feldspar and different sintering temperatures on the sintered properties of ceramic tile bodies was evaluated. The results indicated that sintering ceramic tiles with a high fly ash content at a high temperature caused a decrease in the properties because of bloating. The ceramic samples containing a higher amount of fly ash that were sintered at low temperature exhibited lower water absorption, larger shrinkage and strength because of the densification observed also in microstructural investigation.

    Se ha evaluado la influencia de la proporción de diferentes tipos de cenizas volantes (en lugar de feldespato y diferentes temperaturas de sinterización en las propiedades de soportes cerámicos. Los resultados indicaron que las composiciones con un alto contenido de cenizas volantes provocaron una disminución en las propiedades de las piczas cocidas a alta temperatura como consecuencia del hinchamiento. Las composiciones con una mayor cantidad de cenizas sinterizadas a baja temperatura mostraron una menor absorción de agua, mayor contracción y resistencia mecánica debido a la densificación como también se observó en la investigación microestructural.

  9. A comparison between alkaline and decomplexing reagents to extract humic acids from low rank coals

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, D.; Cegarra, J.; Abad, M. [CSIC, Madrid (Spain). Centro de Edafologia y Biologia Aplicada del Segura

    1996-07-01

    Humic acids (HAs) were obtained from two low rank coals (lignite and leonardite) by using either alkali extractants (0.1 M NaOH, 0.1 M KOH or 0.25 M KOH) or solutions containing Na{sub 4}P{sub 2}O{sub 7} (0.1 M Na{sub 4}P{sub 2}O{sub 7} or 0.1 M NaOH/Na{sub 4}P{sub 2}O{sub 7}). In both coals, the greatest yields were obtained with 0.25 M KOH and the lowest with the 0.1 M alkalis, whereas the extractions based on Na{sub 4}P{sub 2}O{sub 7} yielded intermediate values and were more effective on the lignite. Chemical analysis showed that the leonardite HAs consisted of molecules that were less oxidized and had fewer functional groups than the HAs released form the lignite. Moreover, the HAs extracted by reagents containing Na{sub 4}P{sub 2}O{sub 7} exhibited more functional groups than those extracted with alkali, this effect being more apparent in lignite because of its greater cation exchange capacity. Gel permeation chromatography indicated that the leonardite HAs contained a greater proportion of higher molecular size compounds than the lignite HAs, and that both solutions containing Na{sub 4}P{sub 2}O{sub 7} released HAs with a greater proportion of smaller molecular compounds from the lignite than did the alkali extractants. 16 refs., 3 figs., 2 tabs.

  10. Investigations of the surface tension of coal ash slags under gasification conditions; Untersuchungen zur Oberflaechenspannung von Kohleschlacken unter Vergasungsbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Melchior, Tobias

    2011-10-26

    In the context of CO{sub 2}-emission-induced global warming, greenhouse gases resulting from the production of electricity in coal-fired power plants gain increasing attention. One possible way to reduce such emissions is to gasify coal instead of burning it. The corresponding process is referred to as Integrated Gasification Combined Cycle and allows for the separation of CO{sub 2} before converting a synthesis gas into electrical energy. However, further improvements in efficiency and availability of this plant technology are needed to render the alternative generation of electricity sensible from an economic point of view. One corresponding approach introduces hot gas cleaning facilities to the gasification plant which guarantee a removal of slag particles from the synthesis gas at high temperatures. The development of such filters depends on the availability of data on the material properties of the coal ash slags to be withdrawn. In this respect, the surface tension is a relevant characteristic. Currently, the surface tension of real coal ash slags as well as of synthetic model systems was measured successfully by means of the sessile drop and the maximum bubble pressure method. With regard to the sessile drop technique, those experiments were conducted in a gasification-like atmosphere at temperatures of up to 1500 C. Furthermore, the pressure inside the experimental vessel was raised to 10 bar in order to allow for deriving the influence of this variable on the surface tension. In contrast, maximum bubble pressure trials were realised at atmospheric pressure while the gas atmosphere assured inert conditions. For performing sessile drop measurements, a corresponding apparatus was set up and is described in detail in this thesis. Three computer algorithms were employed to calculate surface tensions out of the photos of sessile drops and their individual performance was evaluated. A very good agreement between two of the codes was found while the third one produces heavily scattering output. The measurement arrangement was run in an almost fully automated fashion which resulted in an immense amount of obtained surface tension data. Maximum bubble pressure experiments were conducted at the University of Osaka, Japan, on selected real ash samples. Due to a far longer time required for determining bubble pressures in comparison to taking drop pictures, only a small number of temperatures could be studied abroad. The results show the surface tension to be in the range from 200 mN/m to 500 mN/m which is in accordance with data taken from the literature. While three discrete temperature intervals of particular slag behaviour could be identified in sessile drop experiments, results of maximum bubble pressure trials suggest the surface tension to be lower under inert conditions compared to a reducing atmosphere. The outcomes generated in Japan additionally show a better agreement to surface tensions forecasted by model calculations. Fe{sub 2}O{sub 3} being considered to have a pronounced influence on slag characteristics is made responsible for such observations. As soon as pressure is applied, the surface tension is found to decrease significantly. In order to visualise the data obtained by means of the sessile drop technique, regression functions were employed that can be implemented into future design calculations on hot gas cleaning facilities. (orig.)

  11. ICP-AES determination of rare earth elements in coal fly ash samples of thermal power stations: assessment of possible recovery and environmental impact of rare earth elements

    International Nuclear Information System (INIS)

    Accurate determination of rare earth elements (REEs) in ashes of thermal power plants is important in the current scenario due to its economic value, and the pollution caused if they are released in to the environment. Their toxicity to living organisms now gaining importance in international community, and some investigation shows it causes retardation in plant growth. In coal based thermal stations huge quantity of coal used annually as a fuel and lakhs of tones of waste is generated in the form of ashes. Therefore studies were carried out on three aspects - fairly rapid and accurate ICP-AES determination REEs in coal fly ash samples using addition technique, a preliminary acid leaching studies on coal received from three different fired thermal power stations using hydrochloric acid at pH 1 and 2, and quantify the REEs leached, and economic recovery of REEs using di-(2-ethylhexyl) phosphoric acid solvent extraction process or precipitation hydroxides using dilute ammonia solution. The standard addition method of REEs determination using rate and reproducible values, besides the analysis is fast compared to the ion exchange separation of REEs followed by the ICP-AES determination. (author)

  12. Composition and morphology of fly ash from fluidized bed combustion of brown coal.

    Czech Academy of Sciences Publication Activity Database

    Sýkorová, Ivana; Smolík, Ji?í; Schwarz, Jaroslav; Kerkkonen, O.; Ku?era, Jan; Havránek, Vladimír

    Essen : P+W Druck und Verlag GmbH, Essen Germany Deutsche Wissenschaftliche Gesellschaft für Erdöl und Kohle, 1997 - (Ziegler, A.; Heek, K.; Klein, J.; Wanzl, W.), s. 1187-1190 ISBN 3-931850-22-6. [International Conference on Coal Science /9./. Essen (DE), 07.09.1997-12.09.1997] R&D Projects: GA ?R GA104/95/0653

  13. Composition and morphology of fly ash from fluidized bed of brown coal.

    Czech Academy of Sciences Publication Activity Database

    Ku?era, Jan; Smolík, J.; Schwarz, J.; Kerkkonen, O.; Sýkorová, I.; Havránek, Vladimír

    Essen : Deutsche Wissenschaftliche Geselschaft für Erdöl and Erdgas und Kohle, 1997 - (Zeigler, A.; van Heek, K.; Klein, J.; Wanzl, W.), s. 1187-1190 ISSN 1433-9013. [International Conference on Coal Science /9./. Essen (DE), 07.10.1997-12.10.1997] Subject RIV: DN - Health Impact of the Environment Quality

  14. Hydraulic activity of belite cement from class C coal fly ash. Effect of curing and admixtures

    Directory of Open Access Journals (Sweden)

    Guerrero, A.

    2006-09-01

    Full Text Available The effect of curing method and a water-reducing additive on the hydraulic activity of high lime content (ASTM type C fly ash belite cement (FABC-2-W is reported. A class C fly ash was subjected to hydrothermal treatment and subsequent calcination to synthesize FABC. Hydraulic activity was evaluated in the cement paste over 180 days from the physically bound water content as determined by thermogravimetric analysis and the degree of hydration, in turn found with X-ray diffraction (XRD analysis. Mechanical strength, porosity and pore size distribution were also studied in equivalent mortar samples.En este trabajo se discute la influencia del tipo de curado y de un aditivo reductor de la demanda de agua en la actividad hidráulica de un cemento belítico de cenizas volantes de alto contenido en cal denominado (CBCV-2-A. Este cemento ha sido sintetizado por una ruta húmeda hidrotermal con posterior calcinación, empleando ceniza volante de alto contenido en cal (ASTM tipo C como materia prima. La actividad hidráulica se ha estudiado en la pasta de cemento, durante un periodo de 180 días, por medio del contenido de agua combinada, determinada por análisis termogravimétrico, y el grado de hidratación por difracción de rayos X (DRX. La resistencia mecánica y la porosidad total y distribución de tamaño de poro se han estudiado en probetas equivalentes de mortero

  15. A new model to estimate CO2 coal gasification kinetics based only on parent coal characterization properties

    International Nuclear Information System (INIS)

    Highlights: • A mathematical model to predict gasification rate and residence time was proposed. • Gasification rate is affected mainly by micropore surface area and alkaline content. • Residence time for coal gasification can be predicted without a kinetic model. • Surface area based on carbon content is an important parameter in kinetic analysis. • The model can predict the kinetic of coal blends in any ash composition range. - Abstract: A new mathematical model is proposed for the estimation of CO2 gasification kinetics of different rank coals and ash contents. There are no previous reports on the determination of the conversion rate or even residence time of CO2 or steam gasification based on coal characterization and for a wide range of ash content. This new approach can be used to infer the residence time and other parameters required for reactor design and operation optimization of newly mined coals or coal mixtures used as feedstock. The coal micropore surface area and the alkaline content determined by the ash composition were proved to be the most significant variables influencing the gasification rate. These variables were correlated to formulate a semi-empirical expression based on the Arrhenius equation. An equation to infer residence time, independent of the kinetic model, is also presented. The new equation is important in understanding the catalytic effect of the alkaline content in the temperature range where the chemical reaction is the controlling step. It can also be used as the corresponding term of the chemical reaction in a gas–solid kinetic model when working at higher temperatures. This new approach is valid, if there is not loss of alkali and alkaline earth metals due to sublimation or melting, which results in a glassy slag structure. The proposed model has direct industrial application in simulation of gasifiers’ performance with the knowledge of only coal characterization properties

  16. Ash particulate formation from pulverized coal under oxy-fuel combustion conditions.

    Science.gov (United States)

    Jia, Yunlu; Lighty, JoAnn S

    2012-05-01

    Aerosol particulates are generated by coal combustion. The amount and properties of aerosol particulates, specifically size distribution and composition, can be affected by combustion conditions. Understanding the formation of these particles is important for predicting emissions and understanding potential deposition. Oxy-fuel combustion conditions utilize an oxygen-enriched gas environment with CO(2). The high concentration of CO(2) is a result of recycle flue gas which is used to maintain temperature. A hypothesis is that high CO(2) concentration reduces the vaporization of refractory oxides from combustion. A high-temperature drop-tube furnace was used under different oxygen concentrations and CO(2) versus N(2) to study the effects of furnace temperature, coal type, and gas phase conditions on particulate formation. A scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) were utilized for particle size distributions ranging from 14.3 nm to 20 ?m. In addition, particles were collected on a Berner low pressure impactor (BLPI) for elemental analysis using scanning electron microscopy and energy dispersive spectroscopy. Three particle size modes were seen: ultrafine (below 0.1 ?m), fine (0.1 to 1.0 ?m), and coarse (above 1 ?m). Ultrafine mass concentrations were directly related to estimated particle temperature, increasing with increasing temperature. For high silicon and calcium coals, Utah Skyline and PRB, there was a secondary effect due to CO(2) and the hypothesized reaction. Illinois #6, a high sulfur coal, had the highest amount of ultrafine mass and most of the sulfur was concentrated in the ultrafine and fine modes. Fine and coarse mode mass concentrations did not show a temperature or CO(2) relationship. (The table of contents graphic and abstract graphic are adapted from ref 27.). PMID:22468843

  17. Melting Behavior of ashes from the co-combustion of coal and straw

    DEFF Research Database (Denmark)

    Arvelakis, Stelios; Frandsen, Flemming

    2007-01-01

    Straw may be used today as a substitute fuel to lower the greenhouse gas emissions from traditional coalfired power plants and provide green-based electricity. It may also provide an alternative source of income to the local farmers helping the developed countries to support sustainable development. The use of straw as a co-firing feedstock in traditional coal-fired plants is associated with operational problems, such as deposition, agglomeration, and/or corrosion, mainly because of the higher a...

  18. Natural rain - induced element leaching from coal ASH; La pluie naturelle - lixiviation d'element de la cendre de charbon

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, A.; Djordjevic, D.; Polic, P. [Belgrade Univ., Dept. of Chemistry, IChTM, Chemistry Center, Belgrade (Yugoslavia)

    2000-07-01

    Six composite samples of coal ash from power plants 'Nikola Tesla' A and B, located in the vicinity of Obrenovac, near Belgrade (Yugoslavia), were subjected to extraction with 1 M acetate solution, pH 5.5, in order to imitate possible leaching of the ash by natural acidic rain. Seven trace and five major elements have been examined, and the obtained amounts were in the range from 0.003 {+-} 0.001 ppm (Cd), to 117 {+-} 27 ppm (Ca), dry ash basis. Though some of the concentrations were higher than allowed by domestic and international regulations it can be concluded that neither of the examined elements represents a serious threat for the environment (at least for the conditions applied in this experiment). Also, both magnesium and iron are carriers of copper, chromium and arsenic, while cadmium is associated with magnesium and manganese. Calcium and manganese are beside magnesium and iron, scavengers of arsenic. (authors)

  19. PURIFICATION AND ENRICHMENT OF BIOGAS IN ASH-WATER MIXTURE

    Directory of Open Access Journals (Sweden)

    Andrzej Brudniak

    2014-10-01

    Full Text Available Biogas, produced in an aerobic digestion process, is a mixture of gases, and that is why its inexpensive and effective valorisation is essential. Research on this process is necessary in order to use biogas as a renewable energy source. The aim of this thesis is to present methods of biogas purification and enrichment in the fly ash - water mixture, that is generated on the base of fly ash produced during burning coal in power industry. Experience presented that the fly ash absorbs CO2 and H2S, even in conventional conditions. The absorption efficiency depends not only on the chemical composition of the ash but also on its physical properties. There was also a strong neutralization of alkaline waste combustion.

  20. Synthesis and characterization of zeolite material from coal ashes modified by surfactant; Sintese e caracterizacao de material zeolitico de cinzas de carvao modificado por surfactante

    Energy Technology Data Exchange (ETDEWEB)

    Fungaro, D.A., E-mail: dfungaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (CQMA/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente; Borrely, S.I. [Instituto de Pesquisas Energeticas e Nucleares (CTR/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes

    2010-07-01

    Coal ash was used as starting material for zeolite synthesis by means of hydrothermal treatment. The surfactant-modified zeolite (SMZ) was prepared by adsorbing the cationic surfactant hexadecyltrimethylammonium bromide (HDTMA-Br) on the external surface of the zeolite from coal ash. The zeolite structure stability was monitored during the characterization of the materials by FTIR, XDR and SEM. The structural parameters of surfactant-modified zeolite are very close to that of corresponding non-modified zeolite which indicates that the crystalline nature of the zeolite remained intact after required chemical treatment with HDTMA-Br molecules and heating treatment for drying. The most intense peaks in the FTIR spectrum of HDTMA-Br were observed in SMZ spectrum confirming adsorption of surfactant on zeolites. (author)

  1. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  2. Pyrite thermochemistry, ash agglomeration, and char fragmentation during pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Akan-Etuk, A.; Diaz, R.; Niksa, S.

    1991-10-01

    The objective of the present work is to introduce an experimental program that will eventually lead to time-resolved iron ash composition over the technological operating domain. The preceding literature survey suggests two important stipulations on any such experimental program. The first stipulation is that good control must be established over the operating conditions, to accurately quantify their effects. The other is that data must be obtained rapidly, to thoroughly cover the important operating domain. This work presents a series of studies that has characterized the desulfurization of pyrite during the early stages of combustion. An experimental system was established and used to monitor the effects of oxygen, temperature, and residence time on the evolution of condensed phase products of the combustion of pure pyrite. (VC)

  3. Anodic performance in lithium-ion batteries of graphite-like materials prepared from anthracites and unburned carbon concentrates from coal combustion fly ashes

    OpenAIRE

    Cameán Martínez, Ignacio; García Suárez, Ana Beatriz; Ramos Alonso, Alberto; Cuesta Pedrayes, Nuria

    2013-01-01

    [EN] The electrochemical performance as anodes for lithium-ion batteries of graphite-like materials that were prepared from anthracites and unburned carbon concentrates from coal combustion fly ashes by high temperature treatment was investigated by galvanostatic cycling of lithium test cells. Some of the materials prepared have provided reversible capacities up to ~ 310 mA h g-1 after 50 discharge/ charge cycles. These values are similar to those of oil-derived graphite (petroleum coke being...

  4. Impact of Coal Fly Ash Addition on Combustion Aerosols (PM2.5) from Full-Scale Suspension-Firing of Pulverized Wood

    DEFF Research Database (Denmark)

    Damø, Anne Juul; Wu, Hao; Frandsen, Flemming; Glarborg, Peter; Sander, Bo

    2014-01-01

    The formation of combustion aerosols was studied in an 800 MWth suspension-fired power plant boiler, during combustion of pulverized wood pellets with and without addition of coal fly ash as alkali capture additive. The aerosol particles were sampled and characterized by a low-pressure cascade impactor (LPI), and elemental composition and particle morphology was studied by electron microscopy methods (SEM/EDS and TEM/EDS). During pulverized wood combustion, the mass-load of submicrometer particl...

  5. Development of bricks with incorporation of coal ash and sludge from water treatment plant; Desenvolvimento de tijolos com incorporacao de cinzas de carvao e lodo provenientes de estacao de tratamento de agua

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Mauro Valerio da

    2011-07-01

    Sludge from treatment water Brazilian plant station are, frequently, disposed and launched directly in the water bodies, causing a negative impact in the environment. Also, coal ashes is produced by burning of coal in coal-fired power stations and is the industrial solid waste most generated in southern Brazil: approximately 4 million tons/y. The efficient disposal of coal ashes is an issue due to its massive volume and harmful risks to the environment. The aim of this work was study the feasibility of incorporating these two industrial wastes in a mass used in the manufacture of ecological bricks. Samples of fly ashes from a cyclone filter from a coal-fired power plant located at Figueira County in Parana State, Brazil and waterworks sludge of Terra Preta County in Sao Paulo State, Brazil, were used in the study. Fly ash-sludge and fly ash-sludge-soil-cement bricks were molded and tested, according to the Brazilians Standards. The materials were characterized by physical-chemical analysis, X-ray diffraction, thermal analysis, morphological analysis, Fourier transform infrared spectroscopy and granulometric analysis. The results indicate that the waterworks sludge and coal ashes have potential to be used on manufacturing soil-cement pressed bricks according to the of Brazilians Standards NBR 10836/94. (author)

  6. Best management practices plan for the Chestnut Ridge-Filled Coal Ash Pond at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    The Chestnut Ridge Filled Coal Ash Pond (FCAP) Project has been established to satisfy Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements for the Chestnut Ridge Operable Unit 2. FCAP is on Chestnut Ridge, approximately 0.5 miles south of the Y-12 Plant. A 62-foot high earthen dam across Upper McCoy Branch was constructed in 1955 to create a pond to serve as a settling basin for fly and bottom ashes generated by burning coal at the Y-12 Steam Plant. Ash from the steam was mixed with water to form a slurry and then pumped to the crest of Chestnut Ridge and released through a large pipe to flow across the Sluice Channel area and into the pond. The ash slurry eventually overtopped the dam and flowed along Upper McCoy Branch to Rogers Quarry. The purpose of this document is to provide a site-specific Best Management Practices (BMP) Plan for construction associated with environmental restoration activities at the FCAP Site

  7. On the use of electrical resistivity methods in monitoring infiltration of salt fluxes in dry coal ash dumps in Mpumalanga, South Africa

    Scientific Electronic Library Online (English)

    Innocent, Muchingami; Jacobus, Nel; Yongxin, Xu; Gideon, Steyl; Kelley, Reynolds.

    Full Text Available One of the principal environmental concerns relating to coal combustion waste disposal is the potential for groundwater contamination from salt fluxes and trace elements that may be leached into the underlying groundwater system. Since changes in moisture and salt concentrations usually provide cont [...] rasts in electrical properties against the host media, electrical resistivity methods can be used to monitor ingression of solute plumes as well as to detect any preferential flow paths within the ash medium. In this study, 2D electrical resistivity tomography was used to monitor brine (10% NaCl) water ingression through the unsaturated zone of a dry coal ash dump at a power station, Mpumalanga, South Africa. This was after the initial laboratory determination of the relation between electrical resistivity and moisture/salt content for the ash dump. The results showed that infiltration plume progression was more pronounced in the vertical direction, suggesting that moisture movement is mainly due to gravitational pull. There was no evidence of preferential flow within the ash medium, although the different infiltration rates for different sites suggested different permeability within the unsaturated zone.

  8. Impairment of soil health due to fly ash-fugitive dust deposition from coal-fired thermal power plants.

    Science.gov (United States)

    Raja, R; Nayak, A K; Shukla, A K; Rao, K S; Gautam, Priyanka; Lal, B; Tripathi, R; Shahid, M; Panda, B B; Kumar, A; Bhattacharyya, P; Bardhan, G; Gupta, S; Patra, D K

    2015-11-01

    Thermal power stations apart from being source of energy supply are causing soil pollution leading to its degradation in fertility and contamination. Fine particle and trace element emissions from energy production in coal-fired thermal power plants are associated with significant adverse effects on human, animal, and soil health. Contamination of soil with cadmium, nickel, copper, lead, arsenic, chromium, and zinc can be a primary route of human exposure to these potentially toxic elements. The environmental evaluation of surrounding soil of thermal power plants in Odisha may serve a model study to get the insight into hazards they are causing. The study investigates the impact of fly ash-fugitive dust (FAFD) deposition from coal-fired thermal power plant emissions on soil properties including trace element concentration, pH, and soil enzymatic activities. Higher FAFD deposition was found in the close proximity of power plants, which led to high pH and greater accumulation of heavy metals. Among the three power plants, in the vicinity of NALCO, higher concentrations of soil organic carbon and nitrogen was observed whereas, higher phosphorus content was recorded in the proximity of NTPC. Multivariate statistical analysis of different variables and their association indicated that FAFD deposition and soil properties were influenced by the source of emissions and distance from source of emission. Pollution in soil profiles and high risk areas were detected and visualized using surface maps based on Kriging interpolation. The concentrations of chromium and arsenic were higher in the soil where FAFD deposition was more. Observance of relatively high concentration of heavy metals like cadmium, lead, nickel, and arsenic and a low concentration of enzymatic activity in proximity to the emission source indicated a possible link with anthropogenic emissions. PMID:26450689

  9. Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

    Directory of Open Access Journals (Sweden)

    Lindiane Bieseki

    2012-01-01

    Full Text Available Zeolite A was synthesized using the coal ash from Siderópolis/RS - Brazil. The synthesis was based on a standard IZA synthesis using coal ash as the Si and Al source. XRF analysis showed that the coal ash has a Si/Al ratio of 1.52, which is close to the Si/Al ratio required to produce zeolite A (1.0. The synthesized materials were analyzed by XRD, SEM and N2 adsorption. More crystalline materials were obtained during synthesis when an additional treatment was applied at a temperature of 353 K at the dissolution of NaOH step. The product formed after 4 hours was the most crystalline, but even the product formed after 1 hour proved to be better than that formed using the standard 4 hours IZA synthesis. The zeolites synthesized by this method had an adsorption capacity of 120 mg.g-1 for Ca2+, half the capacity of commercial zeolite A (300 mg.g-1. It was not possible to obtain blue or green pigments using the synthesized zeolite A.

  10. Zeolite A synthesis employing a brazilian coal ash as the silicon and aluminum source and its applications in adsorption and pigment formulation

    Scientific Electronic Library Online (English)

    Lindiane, Bieseki; Fábio Garcia, Penha; Sibele Berenice Castellã, Pergher.

    2013-02-01

    Full Text Available Zeolite A was synthesized using the coal ash from Siderópolis/RS - Brazil. The synthesis was based on a standard IZA synthesis using coal ash as the Si and Al source. XRF analysis showed that the coal ash has a Si/Al ratio of 1.52, which is close to the Si/Al ratio required to produce zeolite A (1.0 [...] ). The synthesized materials were analyzed by XRD, SEM and N2 adsorption. More crystalline materials were obtained during synthesis when an additional treatment was applied at a temperature of 353 K at the dissolution of NaOH step. The product formed after 4 hours was the most crystalline, but even the product formed after 1 hour proved to be better than that formed using the standard 4 hours IZA synthesis. The zeolites synthesized by this method had an adsorption capacity of 120 mg.g-1 for Ca2+, half the capacity of commercial zeolite A (300 mg.g-1). It was not possible to obtain blue or green pigments using the synthesized zeolite A.

  11. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption.

    Science.gov (United States)

    Medina, Adriana; Gamero, Prócoro; Almanza, José Manuel; Vargas, Alfredo; Montoya, Ascención; Vargas, Gregorio; Izquierdo, María

    2010-09-15

    Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 degrees C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na(2)HAsO(4).7H(2)O originally containing 740 ppb. PMID:20537461

  12. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Adriana [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Gamero, Procoro, E-mail: pgamerom@hotmail.com [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Almanza, Jose Manuel [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Vargas, Alfredo; Montoya, Ascencion [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, G.A. Madero, C.P. 07730, Distrito Federal (Mexico); Vargas, Gregorio [CINVESTAV IPN-Unidad Saltillo, Carretera Saltillo-Monterrey Km 13.5, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Izquierdo, Maria [Instituto de Ciencias de la Tierra ' Jaume Almera' , CSIC, C/Luis Sole Sabaris, s/n 08028 Barcelona (Spain)

    2010-09-15

    Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 {sup o}C; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na{sub 2}HAsO{sub 4}.7H{sub 2}O originally containing 740 ppb.

  13. Fly ash from a Mexican mineral coal. II. Source of W zeolite and its effectiveness in arsenic (V) adsorption

    International Nuclear Information System (INIS)

    Coal-fired plants in Coahuila (Mexico) produce highly reactive fly ash (MFA), which is used in a one-step process as a raw material in producing zeolite. We explored two routes in the synthesis of zeolite: (a) direct MFA zeolitization, which resulted in the formation of W zeolite with KOH and analcime with NaOH and (b) a MFA fusion route, which resulted in the formation of zeolite W or chabazite with KOH and zeolite X or P with NaOH. No residual crystalline phases were present. When LiOH was employed, ABW zeolite with quartz and mullite were obtained. For both zeolitization routes, the nature of the alkali (KOH, NaOH, LiOH), the alkali/MFA ratio (0.23-1.46), and the crystallization temperature and time (90-175 oC; 8-24 h) were evaluated. Additionally, the effect of temperature and time on MFA fusion was studied. W zeolite was obtained by both zeolitization methods. The direct route is preferred because it is a straightforward method using soft reaction conditions that results in a high yield of low cost zeolites with large crystal agglomerates. It was demonstrated that aluminum modified W zeolite has the ability to remove 99% of the arsenic (V) from an aqueous solution of Na2HAsO4.7H2O originally containing 740 ppb.

  14. Performance of double-layer biofilter packed with coal fly ash ceramic granules in treating highly polluted river water.

    Science.gov (United States)

    Jing, Zhaoqian; Li, Yu-You; Cao, Shiwei; Liu, Yuyu

    2012-09-01

    To improve trickling filters' denitrification efficiency, a biofilter with a trickling upper layer and a submerged lower layer was developed and applied in treating highly polluted river water. It was packed with porous coal fly ash ceramic granules. Its start-up characteristics, influence of hydraulic loading rates (HLR), carbon/nitrogen (C/N) ratio and filter depth on pollutants removal were investigated. The results indicated this biofilter was started quickly in 16 days with river sediment as inoculum. Alternating nitrification and denitrification were achieved when water flowed downwards. COD and nitrogen were mainly removed in the upper layer and the lower layer, respectively. With HLR of 4.0-5.0m(3)/(m(2)d), chemical oxygen demand (COD), ammonium (NH(4)(+)-N) and total nitrogen (TN) in the effluent were below 50, 5 and 15 mg/L, respectively. This biofilter removed more than 80% of COD, 85% of NH(4)(+)-N and 60% of TN with C/N ratios ranging from 6 to 10. PMID:22820109

  15. The importance of physical and flow properties in the safe and efficient handling of coal, ash, limestone and gypsum

    Energy Technology Data Exchange (ETDEWEB)

    Wright, H. [Dr. H. Wright & Associates & Solid Engineering Systems Ltd. (United Kingdom)

    1996-12-31

    It seems to be a general assumption that, along with some idea of particle size distribution and bulk density, knowledge of (1) the proximate analysis of coal, (2) the chemical analysis of limestone/gypsum or (3) the amount of carbon in ash, is all that is needed to design safe and efficient power station handling and storage systems. This paper explains why this is not true and how this view can lead to serious losses in the value of ownership (i.e. income of ownership - cost of ownership). Furthermore, hardly any flow property databases exist in either the public or private domain on which existing designs can be appraised and future designs can be based. The important physical and flow properties and their effect on handling and storage are identified. The paper goes on to outline why and how knowledge of these should be applied to the design of reception, stocking, blending, storage, discharge and transportation systems associated with the steam plant generation of power. 8 refs.

  16. DETERMINATION OF THE KINETIC PARAMETERS OF OXY-FUEL COMBUSTION OF COAL WITH A HIGH ASH CONTENT

    Scientific Electronic Library Online (English)

    K. G. P., Nunes; N. R., Marcílio.

    2015-03-01

    Full Text Available Abstract The aim of this study was to determine the kinetic parameters of the oxy-fuel combustion of char from a Brazilian bituminous coal with a high ash content. The char, with a particle diameter of 715 ?m, was prepared in a N2 atmosphere at 1173 K. The oxy-fuel combustion assays were performed u [...] sing a thermobalance at different temperatures and O2/CO2 gas mixtures of different concentrations. According to the unreacted core model, the process is determined by chemical reaction at low temperatures, with an activation energy of 56.7 kJ.kmol-1, a reaction order of 0.5 at 973 K and a reaction order of 0.7 overall. The use of the continuous reaction model did not provide a good fit for the experimental data because the consumption of the particles during the reaction was not constant, as predicted by the model. According to the Langmuir-Hinshelwood model, the activation energy for the first step was 37.3 kJ.kmol-1.

  17. Compression properties of dust cake of fine fly ashes from a fluidized bed coal combustor on a ceramic filter

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.H.; Ha, S.J.; Jang, H.J. [Gyeongsang National University, Jinju (Republic of Korea). Dept. of Chemical Engineering & ERI

    2004-02-16

    Dust cake compressibility of fine fly ashes (from a coal power plant of fluidized bed combustor) on a ceramic filter was carefully investigated under well-controlled conditions and by measuring the cake thickness under filtration conditions using a laser displacement measuring system. Overall cake porosity and pressure drop of dust cake of three different particles of geometric mean diameters: 1.2, 2.2, and 3.6 {mu}m and the adjusted dynamic shape factors: 1.15, 1.28 and 1.64, respectively, were investigated, at face velocities of 0.02-0.08 m/s. Overall cake porosity was strongly dependent on face velocity and mass load but less dependent on particle sizes. It was understood that dust cake was compressed by reduction of previously formed cake layers with drag forces of lately formed dust layers. The expressions for overall cake porosity and pressure drop across the dust cake, and considering the compression effect, were developed with good agreement with experimental results.

  18. Acute pulmonary and systemic effects of inhaled coal fly ash in rats: Comparison to ambient environmental particles

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.R.; Veranth, J.M.; Kodavanti, U.P.; Aust, A.E.; Pinkerton, K.E. [University of California-Davis, Davis, CA (United States). Center of Health & Environmental

    2006-10-15

    The effect of coal fly ash (CFA) on pulmonary and systemic inflammation and injury was measured in male Sprague-Dawley rats exposed to filtered air or CFA for 4 h/day for 3 days. The average concentration of CFA particulate matter less than 2.5 {mu}m (PM2.5) was 1400 {mu} g/m{sup 3}, of which 600 {mu} g/m{sup 3} was PM1. Animals were examined 18 and 36 h postexposure. Chemical analysis of CFA detected silicon, calcium, aluminum, and iron as major components. Total number of neutrophils in bronchoalveolar lavage fluid (BALF) following exposure to CFA was significantly increased along with significantly elevated blood neutrophils. Exposure to CFA caused slight increases in macrophage inflammatory protein-2, and marked increases in transferrin in BALF. Interleukin-1 beta and total antioxidant potential in lung tissues were also increased in rats exposed to CFA. Histological examination of lung tissue demonstrated focal alveolar septal thickening and increased cellularity in select alveoli immediately beyond terminal bronchioles. These responses are consistent with the ability of CFA to induce mild neutrophilic inflammation in the lung and blood following short-term exposure at levels that could be occupationally relevant. However, when comparing the effects of CFA with those of concentrated ambient particles, CFA does not appear to have greater potency to cause pulmonary alterations.

  19. Influence of mechanical activation on the synthesis of Sr-Celsian employing a precursor mixture containing coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Badillo, C. M.; Lopez-Cuevas, J.; Rodriguez-Galicia, J. L.; Gutierrez-Chavarria, C. A.; Pech-Canul, M. I.

    2013-06-01

    Strontium aluminosilicate, SrAl{sub 2}Si{sub 2}O{sub 8} (SAS), was synthesized by a solid state reaction using coal fly ash (CFA) as main raw material. A precursor mixture of SrCO{sub 3}, CFA and Al{sub 2}O{sub 3} was mechanically-activated for times of up to 12 h using an attrition mill, and subsequently sintered at temperatures of 900-1300 degree centigrade. The CFA and the mechanical activation were employed with the aim to promote the transformation from the hexagonal (Sr-Hexacelsian) into the monoclinic (Sr-Celsian) polymorphic form of SAS, since the latter phase is associated with better physical and mechanical properties but the former tends to be the first one to appear. The mean particle size, the crystallite size and the temperature at the end of the curve of weight loss (Tf) decreased, while the specific surface area and the degree of amorphization increased, with increasing milling time. Samples milled for at least 4 h and then sintered at 1100 degree centigrade achieved full transformation into Sr-Celsian. The same result was obtained for sintering temperatures higher than 1100 degree centigrade, independently of milling time. An increment in both the milling time and the sintering temperature allowed us to improve the densification and the mechanical properties of the synthesized materials. (Author)

  20. Influence of mechanical activation on the synthesis of Sr-Celsian employing a precursor mixture containing coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Badillo, C. M.; Lopez-Cuevas, J.; Rodriguez-Galicia, J. L.; Gutierrez-Chavarria, C. A.; Pech-Canul, M. I.

    2013-05-01

    Strontium aluminosilicate, SrAl{sub 2}Si{sub 2}O{sub 8} (SAS), was synthesized by a solid state reaction using coal fly ash (CFA) as main raw material. A precursor mixture of SrCO{sub 3}, CFA and Al{sub 2}O{sub 3} was mechanically-activated for times of up to 12 h using an attrition mill, and subsequently sintered at temperatures of 900-1300 degree centigrade. The CFA and the mechanical activation were employed with the aim to promote the transformation from the hexagonal (Sr-Hexacelsian) into the monoclinic (Sr-Celsian) polymorphic form of SAS, since the latter phase is associated with better physical and mechanical properties but the former tends to be the first one to appear. The mean particle size, the crystallite size and the temperature at the end of the curve of weight loss (Tf) decreased, while the specific surface area and the degree of amorphization increased, with increasing milling time. Samples milled for at least 4 h and then sintered at 1100 degree centigrade achieved full transformation into Sr-Celsian. The same result was obtained for sintering temperatures higher than 1100 degree centigrade, independently of milling time. An increment in both the milling time and the sintering temperature allowed us to improve the densification and the mechanical properties of the synthesized materials. (Author) 24 refs.

  1. Radiobiological assessment of usability of the fly ash from coal-fired power plants in building sector in Turkey

    International Nuclear Information System (INIS)

    In this study, the specific activities of 226Ra, 232Th and 40K radionuclide in the samples of cement and concrete added fly ash (FA) used building sector were measured by using gamma spectrometer with HPGe detector. In order to assess the usability of the samples of the cement and concrete added FA in building sector and the FA samples obtained as a by-product from coal-burning thermic power plants in Turkey in geotechnical applications from radiological point of view, the radium equivalent activity (Raeq), the activity concentration index (I?), the alpha index (I?), the absorbed gamma dose rates (DIO, DDO) and the corresponding effective dose rates (HIO, HDO) caused from the external exposure in indoor and outdoor were calculated and compared with the limit value or the criterion. The results showed that the mean values of the Raeq, I? (except the mean value calculated for the concrete added with 30% Kangal FA), I? (except the mean values calculated for the cement added with 30-35%) and the indoor effective dose rate (except the mean values calculated for the cement added with 30-35% and the concrete added with 30% Kangal FA) were lower than or close to the limit value or the criterion recommended for the safe use of construction materials. (Includes 12 figures and 12 tables)

  2. Phosphate removal from water by a novel zeolite/lanthanum hydroxide hybrid material prepared from coal fly ash.

    Science.gov (United States)

    Xie, Jie; Lai, Li; Lin, Lidan; Wu, Deyi; Zhang, Zhenjia; Kong, Hainan

    2015-10-15

    This study was undertaken to investigate the effectiveness of the hybrid adsorbent, which was synthesized from coal fly ash and was composed of lanthanum hydroxide and zeolite (La-ZFA), for phosphate removal from water. Long-term repeated adsorption tests for 30 days showed that the maximum removal capacity of the material reached 66.09 mg P/g. The fractionation of adsorbed phosphorus indicated that phosphate immobilized by La-ZFA was quite irreversible and was dominated by HCl-P fraction. It was suggested that the immobilization of phosphate was mainly attributed to lanthanum hydroxide and was slightly influenced by coexistence of other anions (Cl(-), NO3(-), SO4(2-), and HCO3(-)). At a La/P molar ratio between 1.5:1 and 2.0:1, a nearly complete removal (above 98%) of phosphate could be achieved. La-ZFA also exhibited great performance for removing phosphate from lake water (97.29%) as well as the effluent from wastewater treatment plant (97.86%), respectively. In addition, based on the results of the present study, it was believed that La-ZFA could be a potential material for phosphate removal in practical application. PMID:26301857

  3. Alkylation of phenol with tert-butyl alcohol over a catalyst synthesized from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Ojha, K.; Pradhan, N.C.; Samanta, A.N. [Indian Institute of Technology, Kharagpur (India). Dept. of Chemical Engineering

    2006-04-15

    The alkylation of phenol with tert-butyl alcohol was carried out in a continuous flow reactor over a catalyst synthesized from fly ash. The activity of the synthesized catalyst was compared with those of other conventional zeolite catalysts such as 13X (NaX) and H{beta}. Of all the catalysts tested, zeolite H{beta} showed the highest activity in phenol conversion followed by the synthesized zeolite (HZOP-31). The activity of commercial 13X zeolite was found to be same as that of HZOP-31. Ce-exchanged catalyst (CeZOP-31) showed even better performance than 13X in the alkylation of phenol. The effects of different parameters such as reactant mole ratio, temperature and space velocity on phenol conversion and tert-butyl phenol selectivity were studied. The effect of mass transfer resistance was found to be negligible within the feed rate range and particle size range studied. The apparent activation energy for the reaction of tert-butyl alcohol over HZOP-31 was determined as 30.1 kJ mol{sup -1}.

  4. Jatropha curcas: A potential crop for phytoremediation of coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Jamil, S.; Abhilash, P.C.; Singh, N.; Sharma, P.N. [National Botany Research Institute, Lucknow (India)

    2009-12-15

    A greenhouse pot experiment was conducted to test the heavy metal phytoremediation capacity of Jatropha curcas from fly ash. Both natural accumulation by J. curcas and chemically enhanced phytoextraction was investigated. Plants were grown on FA and FA amended with fertile garden soil, in presence and absence of chemical chelating agent EDTA at 0.1 g kg{sup -1} and 0.3 g kg{sup -1} of soil. EDTA enhanced the uptake of all five elements (Fe, Al, Cr, Cu and Mn) tested. Fe and Mn were retained more in roots while Cu, Al and Cr were translocated more to the shoot. Metal accumulation index indicates that the effect of EDTA at 0.3 g kg{sup -1} was more pronounced than EDTA at 0.1 g kg{sup -1} in terms of metal accumulation. Biomass was enhanced up to 37% when FA was amended with GS. Heavy metal uptake was enhanced by 117% in root, 62% in stem, 86% in leaves when EDTA was applied at 0.3 g kg{sup -1} to FA amended with GS. Study suggest that J. curcas has potential of establishing itself on FA when provided with basic plant nutrients and can also accumulate heavy metals many folds from FA without attenuating plant growth.

  5. Coal Ash Behavior in Reducing Environments (CABRE) III Year 6 - Activity 1.10 - Development of a National Center for Hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Stanislowski, Joshua; Azenkeng, Alexander; McCollor, Donald; Galbreath, Kevin; Jensen, Robert; Lahr, Brent

    2012-03-31

    The Energy & Environmental Research Center (EERC) has been conducting research on gasification for six decades. One of the objectives of this gasification research has been to maximize carbon conversion and the water–gas shift process for optimal hydrogen production and syngas quality. This research focus and experience were a perfect fit for the National Center for Hydrogen Technology ® (NCHT®) Program at the EERC for improving all aspects of coal gasification, which ultimately aids in the production and purification of hydrogen. A consortia project was developed under the NCHT Program to develop an improved predictive model for ash formation and deposition under the project entitled “Coal Ash Behavior in Reducing Environments (CABRE) III: Development of the CABRE III Model.” The computer-based program is now applicable to the modeling of coal and ash behavior in both entrained-flow and fluidized-bed gasification systems to aid in overall gasification efficiency. This model represents a significant improvement over the CABRE II model and runs on a Microsoft Windows PC platform. The major achievements of the CABRE III model are partitioning of inorganic transformations between various phases for specific gas cleanup equipment; slag property predictions, including standard temperature–viscosity curves and slag flow and thickness; deposition rates in gasification cleanup equipment; provision for composition analysis for all input and output streams across all process equipment, including major elements and trace elements of interest; composition analysis of deposit streams for various deposit zones, including direct condensation on equipment surfaces (Zone A), homogeneous particulate deposition (Zone B), and entrained fly ash deposition (Zone C); and physical removal of ash in cyclones based on D50 cut points. Another new feature of the CABRE III model is a user-friendly interface and detailed reports that are easily exportable into Word documents, Excel spreadsheets, or as pdf files. The user interface provides stepwise guides with built-in checks for efficient entry of required input data on fuels of interest to allow a successful execution of the model. The model was developed with data from several fuels selected by the sponsors, including bituminous coal, subbituminous coal, lignite, and petroleum coke (petcoke). The data from these fuels were obtained using small pilot-scale entrained-flow and fluidized-bed gasifiers at the Energy & Environmental Research Center (EERC). The CABRE III model is expected to further advance the knowledge base for the NCHT® Program and, more importantly, allow for prediction of the slagging and fouling characteristics of fuels in reducing environments. The information obtained from this program will potentially also assist in maintaining prolonged gasifier operation free from failure or facilitate troubleshooting to minimize downtime in the event of a problem.

  6. Recycling of wood ash in Sweden - an overview

    International Nuclear Information System (INIS)

    This article focuses on the recycling of wood ash from large scale wood combustion back to the forest soil. The heavy metal content of wood ashes, its highly alkaline nature, and environmental effects of recycling the ash are discussed. (UK)

  7. A Geochemical Analytical Scheme for the Appraisal of Partitioning and Mobility of Major elements in Weathered Dry Disposed Coal Fly Ash

    Directory of Open Access Journals (Sweden)

    S. A. Akinyemi

    2011-12-01

    Full Text Available

    South Africa is endowed with significant deposits of coal which is utilized in electricity generation to meet the nation’s energy demand. A large volume of waste solid residue from the combustion of pulverized feed coal in power stations is dry disposed in stock piles or dumps. Chemical interactions of dry disposed fly ash with ingressed CO2 from the atmosphere and infiltrating rain water would cause dissolution of the soluble components in the fly ash matrix. Chemical partitioning and mobility of major elements in samples from cores drilled into serially stacked weathered dry disposed fly ash were investigated using a modified five steps sequential extraction scheme. A total acid digestion was carried out on the original ash core samples prior to extraction to validate the extraction procedure. The geochemical distribution of the investigated major elements in 59 drilled core samples was determined by x-ray fluorescence and inductively coupled plasma mass spectrometry. The relationship between SiO2 and chemical index of alteration (CIA showed 8 year and 20-year-old core samples have a moderate to high degree of weathering. Conversely, 1-year-old cores samples showed characteristics between low and moderate-high degrees of weathering. A cluster and discriminant analysis of the major elements was also able to reveal the subtle chemical alteration differences of the core samples. Functional analysis revealed the disparities in the dissolution patterns of major soluble components in the matrix of the drilled core samples. Modified sequential extractions revealed high concentration of the major species in the leachates for every mineralogical fraction; although the bulk of the major elements are locked up in the insoluble phase of the core samples (i.e. residual fraction which would not be released under normal environmental conditions. It is noteworthy that the concentration of major elements in the labile fractions (water soluble + exchangeable + carbonate was high and this has implications for the long-term durability of residual mineral phases. Relative enrichment and depletion trends of major elements are promoted by heterogeneity in the ash dump (i.e. moisture content, gradual reduction of pore water pH and continuous brine and water irrigation.

    Key words: Coal fly ash; Weathering; Sequential extraction scheme; Cluster analysis; Factor Analysis 

  8. Melting and Sintering of Ashes

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug

    1997-01-01

    The thesis contains an experimental study of the fusion and sintering of ashes collected during straw and coal/straw co-firing.A laboratory technique for quantitative determination of ash fusion has been developed based on Simultaneous Thermal Analysis (STA). By means of this method the fraction of melt in the investigated ashes has been determined as a function of temperature. Ash fusion results have been correlated to the chemical and mineralogical composition of the ashes, to results from a s...

  9. Bare face red-brown bricks manufactured with fly ash from the Narcea (Asturias Coal Power Plan

    Directory of Open Access Journals (Sweden)

    Ayesta, G.

    1999-12-01

    Full Text Available Fly ash, from the Coal Power Plant of Narcea (Asturias, has been used to determine its possible use as a raw material in the bare face red-brown brick manufacture. The correct mould of a ceramic material demands a paste with an adequate plasticity. So, the optimum compositions of humidity, lubricant (talc and binder (white dextrin have been investigated. The samples were made by compressing paste into a mould using varying values of pressure and boiling temperature once the cooling speed had been established. Finally, the cooked pieces were submitted to trials demanded by the Basic Construction Norm, to see if they met the required specifications concerning Water Absorption, Suction, Contraction, Resistance to Freezing, Efflorescence and Compressive Strength.

    Se caracterizan las cenizas volantes de la Central Térmica del Narcea (Asturias para determinar su utilización como materia prima en la obtención de ladrillos cara vista. El moldeo correcto de una pieza cerámica exige trabajar una pasta con una adecuada plasticidad, para ello se investiga cuál ha de ser la composición óptima de la misma, en cuanto a: humedad, cantidad de lubricante (talco y de ligante (dextrina blanca. El conformado de las piezas o ladrillos se realiza por prensado, utilizando distintos valores de presión, así como la temperatura de cocción, una vez establecida la velocidad de enfriamiento. Finalmente, las piezas cocidas se someten a los ensayos exigidos por la Norma Básica de Edificación, para ver si cumplen las especificaciones requeridas en cuanto a: Absorción de agua. Succión, Contracción, Heladicidad, Eflorescencia y Resistencia a la compresión.

  10. Performance of in-vessel composting of food waste in the presence of coal ash and uric acid

    International Nuclear Information System (INIS)

    Highlights: ? The amendments of CA and UA could facilitate the composting performance. ? The overall performance is a sum of different events with different mechanisms. ? The added CA and UA might lead to higher pH during the composting. ? The process is correlated with the variations of microbial activity and C/N ratio. ? The presence of CA and UA has significant influence on composting of food waste. - Abstract: Massive quantities of food waste often coexist with other agroindustrial and industrial waste, which might contain coal ash (CA) and uric acid (UA). This study investigated the influence of CA and UA on the composting of food waste in the in-vessel system. The patterns of food waste composting were compared among various combinations. The results showed that the temperature level was enhanced in the presence of CA and UA during the first 8 days. The significant drop in pH was observed in the treatment without any amendment. But the presence of CA could alleviate the drop of pH. More intensive organic mass reduction took place in the treatments with amended CA and UA in the first half of process. The O2 uptake rate in the reactor with CA and UA was higher than that with only CA in the early stage. Both thermophilic and mesophilic microorganisms were present throughout the composting period. The populations of both thermophilic and mesophilic microorganisms were influenced when amended with CA and UA. The decreasing trend in C/N ratio was shown in all the reactors, while a relatively lower C/N ratio was obtained in the series with both CA and UA.

  11. Performance of in-vessel composting of food waste in the presence of coal ash and uric acid

    Energy Technology Data Exchange (ETDEWEB)

    An, Chun-Jiang [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada); Huang, Guo-He, E-mail: huang@iseis.org [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada); Yao, Yao; Sun, Wei [Faculty of Engineering and Applied Science, University of Regina, Regina, Saskatchewan, S4S 0A2 (Canada); An, Kai [MOE Key Laboratory of Regional Energy Systems Optimization, S and C Academy of Energy and Environmental Research, North China Electric Power University, Beijing 102206 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer The amendments of CA and UA could facilitate the composting performance. Black-Right-Pointing-Pointer The overall performance is a sum of different events with different mechanisms. Black-Right-Pointing-Pointer The added CA and UA might lead to higher pH during the composting. Black-Right-Pointing-Pointer The process is correlated with the variations of microbial activity and C/N ratio. Black-Right-Pointing-Pointer The presence of CA and UA has significant influence on composting of food waste. - Abstract: Massive quantities of food waste often coexist with other agroindustrial and industrial waste, which might contain coal ash (CA) and uric acid (UA). This study investigated the influence of CA and UA on the composting of food waste in the in-vessel system. The patterns of food waste composting were compared among various combinations. The results showed that the temperature level was enhanced in the presence of CA and UA during the first 8 days. The significant drop in pH was observed in the treatment without any amendment. But the presence of CA could alleviate the drop of pH. More intensive organic mass reduction took place in the treatments with amended CA and UA in the first half of process. The O{sub 2} uptake rate in the reactor with CA and UA was higher than that with only CA in the early stage. Both thermophilic and mesophilic microorganisms were present throughout the composting period. The populations of both thermophilic and mesophilic microorganisms were influenced when amended with CA and UA. The decreasing trend in C/N ratio was shown in all the reactors, while a relatively lower C/N ratio was obtained in the series with both CA and UA.

  12. Fertilizer response of compound fertilizer containing coal fly ash on the growth, yield and nutrients absorption of potato plants

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, M. [and others] [CRIEPI, Abiko-shi (Japan). Abiko Research Lab.

    1995-12-31

    Fertilizer response tests were carried out to clarify the effects of application of compound fertilizer containing fly ash on the growth, yield and absorption of fertilizer nutrients of potato plants cultivated in volcanic ash soil. 1. Number of tubers weight of above ground parts and weight of tubers of a stamp of potatoes were greater then when compound fertilizer containing fly ash was used. 2. Absorption of potassium and phosphoric acid by potato plants cultivated in volcanic ash soil was greater when the compound fertilizer containing fly ash was used. 3. Heavy metal contents (Hg, As, Cd, Pb, Cr) in potatoes were not affected by the application of the compound fertilizer containing fly ash used in this study.

  13. Cinza e carbonato de cálcio na mitigação de drenagem ácida em estéril de mineração de carvão / Coal ash and calcium carbonate on acid drainage mitigation in coal mining overburden

    Scientific Electronic Library Online (English)

    Evaldo Rodrigues, Soares; Jaime Wilson Vargas de, Mello; Carlos Ernesto G.R., Schaefer; Liovando Marciano da, Costa.

    2006-02-01

    Full Text Available A drenagem ácida é um problema ambiental, não-exclusivo, mas comumente associado à mineração do carvão e decorrente da oxidação de sulfetos, como a pirita, presente nos estéreis e rejeitos da mineração. A cinza derivada da queima do carvão constitui um resíduo, de utilização ainda limitada, no Brasi [...] l, mas que apresenta potencial de neutralização da acidez. Desse modo, estudou-se a possibilidade de utilização de cinzas da combustão do carvão mineral em combinação com carbonato de cálcio (CaCO3) para correção da drenagem ácida decorrente da oxidação de pirita em estéril da mineração de carvão de Candiota (RS). Amostras de 50 g do material estéril que continha pirita foram tratadas com 16 combinações de cinza da combustão do carvão e CaCO3 e acondicionadas em frascos de lixiviação. O experimento foi realizado em delineamento inteiramente casualizado, fatorial 4 x 4 (quatro doses de CaCO3 e quatro doses de cinza), em três repetições. Os frascos foram submetidos a lixiviações periódicas com água destilada, a cada duas semanas, durante oito meses. Os lixiviados foram caracterizados quanto ao pH, acidez livre e concentrações de S, Si e Fe. Os resultados demonstraram que: o uso da cinza do carvão de Candiota não é viável, tanto por apresentar baixa capacidade de neutralização da acidez quanto por diminuir a eficiência do CaCO3. Após oito meses de intemperismo simulado, apenas 11 % dos sulfetos foram oxidados na ausência de carbonato e cinzas. O uso de carbonato e, em menor grau, de cinza, acelerou a taxa de oxidação dos sulfetos. A oxidação da pirita contida nas amostras ocorreu com maior velocidade nos dois primeiros meses de intemperismo simulado; desse modo, recomenda-se o uso de calcário logo após a exposição do estéril da mineração, visando minimizar a drenagem ácida. Pesquisas, de longo prazo, que visem à otimização das doses de CaCO3 e ao uso de outros corretivos na mitigação da drenagem ácida devem ser estimuladas. Abstract in english Acid drainage is an environmental problem, not exclusive, but commonly associated to coal mines. It arises from the oxidation of sulfides, like pyrite, in overburden and mining tailings. The use of ashes from coal combustion is still limited in Brazil, but such residues have a potential use as neutr [...] alizing agent for acid mine drainage. This study intended to evaluate the interaction between the use of coal ash and CaCO3 to neutralize acid drainage from pyrite oxidation in coal mining overburden from Candiota (RS) - Brazil. Samples of overburden material containing pyrite were treated with increasing CaCO3 doses and coal ash in leaching flasks. The treatments were disposed in a completely randomized design in 4 x 4 factorial scheme (4 doses of CaCO3 and 4 doses of coal ash) with three replications. The flasks were submitted every two weeks to leaching with distilled water during eight months. The leached solutions were analyzed for pH, free acidity and S, Si and Fe contents. Results showed that the use of ash was impractical not only due to its low neutralizing capacity, but also because it reduced the CaCO3 efficiency. After eight months of simulated weathering only 11% of the sulfides were oxidized in the absence of ash or carbonate. The use of CaCO3 and, to a lesser extent of ash, increased the pyrite oxidation rate. Pyrite in coal overburden oxidized faster in the first two months of simulated weathering, thus it is recommended that lime be applied just after overburden exposition in order to minimize acid drainage. Further investigation aiming to optimize the CaCO3 doses and test alternative neutralizing materials in long term experiments should be encouraged.

  14. Natural radioactivity of ground waters and soil in the vicinity of the ash repository of the coal-fired power plant ''Nikola Tesla'' A - Obrenovac (Yugoslavia)

    International Nuclear Information System (INIS)

    Radioactivity of U, Th and 40K has been tested in the vicinity of the ash repository of coal-fired power plant ''Nikola Tesla'' A in Obrenovac (Yugoslavia). By using the methods of alpha and gamma spectrometry, as well as luminescence spectrophotometry, it has been found that the ash repository is a source of radionuclides of the uranium and thorium series and spreads direction of ground waters up to a distance of several hundred metres. The influence of the repository on the soil radioactivity has been found to be minimal, whereas the balance of the first members of series (238U-234U-230Th; 232Th-228Th) has not been disturbed. (Author)

  15. Bioaccumulation of metals in three freshwater mussel species exposed in situ during and after dredging at a coal ash spill site (Tennessee Valley Authority Kingston Fossil Plant).

    Science.gov (United States)

    Otter, Ryan R; McKinney, David; Brown, Bobby; Lainer, Susan; Monroe, William; Hubbs, Don; Read, Bob

    2015-06-01

    On December 22, 2008, a dike containing coal fly ash at the Tennessee Valley Authority Kingston Fossil Plant (TN, USA) failed, and within months, dredging operations began to remove ash-contaminated sediments. The purpose of this study was to investigate differences in the bioaccumulation of metals in three mussel species during and after dredging operations. Mussels were caged for approximately 1 year during dredging and after, and then mussel condition index values and As, Cd, Cr, Pb, Ni, Se, Hg, U, Fe, Mg, Al, Sb, Ba, Be, Co, Cu, Mn, Mo, Ag, Sr, Tl, V, and Zn concentrations in soft tissue were determined via inductively coupled plasma-mass spectrometery. Overall, the differences observed in metal bioaccumulation and mussel health suggest that mussels in the immediate downstream area of the dredging site may have been impacted, as evidenced by a significant decrease in mussel condition index values, but that this impact did not result in increased tissue concentrations of metals. PMID:25957195

  16. Effect of Na2O/SiO2 mole ratio on the crystal type of zeolite synthesized from coal fly ash

    Directory of Open Access Journals (Sweden)

    PREDRAG LAZIC

    2003-06-01

    Full Text Available Coal fly ash was modified to zeolitic materials by hydrothermal treatment at 90ºC. The zeolite synthesis was studied as a function of the mole ratio of Na2O/SiO2 in the reaction mixtures. The results showed that NaP1 zeolite is obtained when the Na2O/SiO2 mole ratio was 0.7. Hydroxysodalite is the dominant zeolite phase in modified fly ash treated with a higher Na2O concentration solution (Na2O/SiO2 = 1.3. The IR and XRD methods were used to determine the phases present in the starting sample and in the zeolitic materials.

  17. Direct solid sampling electrothermal atomic absorption spectrometric determination of toxic and potentially toxic elements in certified reference materials of brown coal fly ash

    International Nuclear Information System (INIS)

    This work describes a method for the direct determination of Bi, Cd, Cr, Ni, Pb, Sb, Sn and Zn in reference materials of brown coal fly ash, using solid sampling electrothermal atomic absorption spectrometry. The use of chemical modifiers was found to be necessary for obtaining reproducible and sufficiently sensitive signals for the analytes under study. The mixture of Pd and Mg(NO3)2 was used for the determination of Bi, Cd, Pb, Sb, Sn and Zn, W (permanent modifier) in combination with Mg(NO3)2 (as aqueous modifier) provided well-defined signal profiles for Cr and Ni determination in coal fly ash samples. A systematic study focused on the use of alternative (less sensitive) lines for obtaining sufficient sensitivity. The following analytical lines were used: Bi 306.8 nm, Cd 326.1 nm, Cr 520.6 nm, Ni 305.1 nm, Pb 205.3 nm, Sb 206.8 nm, Sn 300.9 nm, Zn 307.6 nm. The limits of detection were 0.057 ?g g?1 for Bi, 0.21 ?g g?1 for Cd, 1.1 ?g g?1 for Cr, 1.4 ?g g?1 for Ni, 4.0 ?g g?1 for Pb, 0.13 ?g g?1 for Sb, 0.33 ?g g?1 for Sn and 16 ?g g?1 for Zn, respectively. - Highlights: ? DSS-ETAAS might be an attractive alternative to the conventional ETAAS. ? Direct analysis of solids could be used in order to improve the sampling capacity. ? The CRMs of coal fly ashes were used for development of the DSS-ETAAS method. ? Selection of suitable modifiers to achieve the unification of atomization kinetics. ? DSS-ETAAS used for direct determination of potentially toxic and toxic elements.

  18. Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM2.5) Fraction of Coal Combustion Ash

    Energy Technology Data Exchange (ETDEWEB)

    T. L. Robl; J. G. Groppo; R. Rathbone; B. Marrs; R. Jewell

    2008-07-18

    The overall objective of this research was to determine the feasibility of recovering a very fine fraction of fly ash, that is 5 microns in diameter or less and examining the characteristics of these materials in new or at least less traditional applications. These applications included as a polymer filler or as a 'super' pozzolanic concrete additive. As part of the effort the ash from 6 power plants was investigated and characterized. This work included collection from ESP Hoppers and ponds. The ash was thoroughly characterized chemically and physically. Froth flotation was used to reduce the carbon and testing showed that flotation could effectively reduce carbon to acceptable levels (i.e. 0.5% LOI) for most of the substrates tested. in order to enable eventual use as fillers. Hydraulic classification was used in the separation of the fine ash from the coarse ash. Hydraulic classification requires the ash to be dispersed to be effective and a range of dispersants were tested for adsorption as well as sedimentation rate. A wide range of dosages were required (0.3 to 10 g/kg). In general the ponded ash required less dispersant. A model was developed for hydraulic classification. A pilot-scale hydraulic classifier was also designed and operated for the project. Product yields of up to 21% of feed solids were achieved with recoveries of <5 {micro}m particles as high as 64%. Mean particle sizes (D{sub 50}) of the ultra fine ash (UFA) products varied from 3.7 to 10 {micro}m. A patent was filed on the classifier design. A conceptual design of a Process Demonstration Unit (PDU) with a feed rate of 2 tons of raw ash feed per hour was also completed. Pozzolanic activity was determined for the UFA ashes in mortars. In general the overall strength index was excellent with values of 90% achieved in 3 days and {approx}100% in 7 days. Three types of thermoplastic polymers were evaluated with the UFA as a filler: high density polyethylene, thermoplastic elastomer and polyethylene terphthalate filled polymers were prepared and subjected to SEM analysis to verify that the UFA was well dispersed. The addition of fillers increased the modulus of the HDPE composite, but decreased both the offset yield stress and offset yield strain, showing that the fillers essentially made the composite stiffer but the transition to plastic deformation occurred earlier in filled HDPE as stress was applied. Similar results were obtained with TPE, however, the decrease in either stress or strain at offset yield were not as significant. Dynamic mechanical analyses (DMA) were also completed and showed that although there were some alterations in the properties of the HDPE and TPE, the alterations are small, and more importantly, transition temperatures are not altered. The UFA materials were also tested in expanded urethanes, were improvements were made in the composites strength and stiffness, particularly for lighter weight materials. The results of limited flammability and fire safety testing were encouraging. A flowsheet was developed to produce an Ultra-Fine Ash (UFA) product from reclaimed coal-fired utility pond ash. The flowsheet is for an entry level product development scenario and additional production can be accommodated by increasing operating hours and/or installing replicate circuits. Unit process design was based on experimental results obtained throughout the project and cost estimates were derived from single vendor quotes. The installation cost of this plant is estimated to be $2.1M.

  19. Remoção de íons Zn2+, Cd2+ e Pb2+ de soluções aquosas usando compósito magnético de zeólita de cinzas de carvão / Removal of Zn2+, Cd2+ e Pb2+ ions from aqueous solutions by magnetic composite of zeolite from coal ashes

    Scientific Electronic Library Online (English)

    Denise Alves, Fungaro; Mitiko, Yamaura; José Eduardo Alves, Graciano.

    Full Text Available [...] Abstract in english For this study, magnetic composite of zeolite-magnetite was prepared by mixing magnetite nanoparticles suspension with synthetic zeolite. The nanoparticles in suspension were synthesized by precipitating iron ions in a NaOH solution. The zeolite was synthesized from coal fly ash by alkaline hydrothe [...] rmal treatment. The magnetic composite was characterized by XDR, SEM, magnetization measurements, IR, and BET surface area. Batch tests were carried out to investigate the adsorption of metal ions of Zn2+, Cd2+ and Pb2+ from aqueous solution onto magnetic composite. Adsorption isotherms were analyzed using Freundlich and Langmuir equations. The adsorption equilibrium data fitted well to the Langmuir equation with maximum adsorption capacities in the range of 28.5-127 mg g-1.

  20. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt; Glarborg, Peter

    2009-01-01

    Ash deposits formed during fuel thermal conversion and located on furnace walls and on convective pass tubes, may seriously inhibit the transfer of heat to the working fluid and hence reduce the overall process efficiency. Combustion of biomass causes formation of large quantities of troublesome ash deposits which contain significant concentrations of alkali, and earth-alkali metals. The specific composition of biomass deposits give different characteristics as compared to coal ash deposits, i.e...

  1. Assessments of Class F fly ashes for amelioration of soil acidity and their influence on growth and uptake of Mo and Se by canola

    Energy Technology Data Exchange (ETDEWEB)

    V. Manoharan; I.A.M. Yunusa; P. Loganathan; R. Lawrie; C.G. Skilbeck; M.D. Burchett; B.R. Murray; D. Eamus [University of Technology, Sydney, NSW (Australia). Department of Environmental Sciences

    2010-11-15

    Coal fly ash can be used to ameliorate productivity constraints in agricultural soils, but their efficacy still remains highly variable. To ascertain the capacity of Class F fly ashes to modify pH of acidic soils, and their effects on the yield and uptake of molybdenum (Mo) and selenium (Se) by canola (Brassica napus L.), we applied two acidic and two alkaline Class F ashes at rates equivalent to 0, 12, 36, and 108 Mg/ha to the top layer (0-10 cm) of 100 cm long intact cores of acidic sandy clay and clay loam soils. Only the alkaline ash which had the highest calcium carbonate equivalent (2.43%) increased the pH of the top 10 cm of the sandy clay soil. However, this ash was also highly saline and when applied at {>=}36 Mg/ha it increased the electrical conductivity in the top soil layer. Increases in soil pH as a result of alkaline ash addition also elevated concentrations of Se in the plant shoot. The ashes with high concentrations of Mo and Se generally increased uptake of these elements in the plant shoot and/or seed. When these ashes were applied at 108 Mg/ha they increased the concentrations of these elements in the treated topsoil. 30 refs., 3 figs., 6 tabs.

  2. Evaluation and demonstration of remediation alternatives for historical mine waste using ash and alkaline by products; Utvaerdering och demonstration av efterbehandlingsalternativ foer historiskt gruvavfall med aska och alkaliska restprodukter

    Energy Technology Data Exchange (ETDEWEB)

    Baeckstroem, Mattias; Sartz, Lotta; Karlsson, Stefan (MTM, Man-Technology-Envionrment, Oerebro Univ., 701 82 Oerebro (Sweden))

    2009-03-15

    The results clearly show that the use of alkaline by products can significantly reduce the leakage of trace metals from historical acid mine waste. Under ideal conditions (laboratory experiments) pH increase significantly and the trace metal concentrations decrease with around 99% compared to the untreated reference. During more realistic conditions (pilot scale) the same increase in pH was not obtained and thus the decrease in trace metal concentrations was not as great. In the stabilisation experiments pH was between 5.8 and 6.8 while the trace metal reduction was around 96-99%. In the filter experiments a median pH between 4 (aged ash) and 10 (lime kiln dust) was obtained after the alkaline section. Average metal reduction is around 95% for cadmium, copper and lead while it is slightly lower for zinc (85%). In summary it is indicated that hydroxide dominated materials work best in aerated environments while carbonate dominated materials work best in reducing environments. In summary it can be concluded that the use of alkaline by products to neutralise acidic mine waste and acid mine drainage from historical mine sites give rise to both environmental and economical benefits and should therefore be encouraged as a sustainable remediation method

  3. Influence of mechanical activation on the synthesis of Sr-Celsian employing a precursor mixture containing coal fly ash

    Directory of Open Access Journals (Sweden)

    López-Badillo, C. M.

    2013-04-01

    Full Text Available Strontium aluminosilicate, SrAl2Si2O8 (SAS, was synthesized by a solid state reaction using coal fly ash (CFA as main raw material. A precursor mixture of SrCO3, CFA and Al2O3 was mechanically-activated for times of up to 12 h using an attrition mill, and subsequently sintered at temperatures of 900-1300 °C. The CFA and the mechanical activation were employed with the aim to promote the transformation from the hexagonal (Sr-Hexacelsian into the monoclinic (Sr-Celsian polymorphic form of SAS, since the latter phase is associated with better physical and mechanical properties but the former tends to be the first one to appear. The mean particle size, the crystallite size and the temperature at the end of the curve of weight loss (Tf decreased, while the specific surface area and the degree of amorphization increased, with increasing milling time. Samples milled for at least 4 h and then sintered at 1100 °C achieved full transformation into Sr-Celsian. The same result was obtained for sintering temperatures higher than 1100 °C, independently of milling time. An increment in both the milling time and the sintering temperature allowed us to improve the densification and the mechanical properties of the synthesized materials.Aluminosilicato de estroncio, SrAl2Si2O8 (SAS, fue sintetizado por reacción en el estado sólido empleando ceniza volante (CFA como materia prima principal. Una mezcla precursora de SrCO3, CFA y Al2O3 fue activada mecánicamente por tiempos de hasta 12 h en un molino de atrición, y después sinterizada a temperaturas de 900-1300 °C. El empleo de la CFA y la activación mecánica tuvieron el propósito de promover la transformación polimórfica de la fase hexagonal (Hexacelsiana de Sr a la monoclínica (Celsiana de Sr del SAS, ya que esta última se asocia con mejores propiedades físicas y mecánicas pero la primera tiende a aparecer primero. El tamaño promedio de partícula y de cristalita, así como la temperatura al final de la curva de pérdida en peso (Tf, disminuyeron, mientras que el área superficial y el grado de amorfización aumentaron, al incrementar el tiempo de molienda. Las muestras molidas por al menos 4 h y sinterizadas a 1100 °C se transformaron completamente a Celsiana de Sr. Sucedió lo mismo a temperaturas de sinterización mayores a 1100 °C, independientemente del tiempo de molienda. El incremento tanto en el tiempo de molienda como en la temperatura de sinterización permitió mejorar la densificación y las propiedades mecánicas de los materiales sintetizados.

  4. The impacts of alkaline mine drainage on Ba, Cr, Ni, Pb and Zn concentration in the water resources of the Takht coal mine, Iran

    Scientific Electronic Library Online (English)

    Behnaz, Dahrazma; Mehdi, Kharghani.

    2012-12-01

    Full Text Available La liberación de metales pesados en el medio ambiente representa uno de los efectos ambientales más importantes en la extracción de carbón, lo cual necesita ser estudiado con mayor profundidad. El presente estudio investigó los efectos de la minería del carbón en un ambiente alcalino y en el drenaje [...] de la mina de carbón Takht, con respecto a la distribución de determinados metales pesados (Zn, Pb, Ni, Cr y Ba) en superficie y en las aguas subterráneas de la región. La mina está ubicada a 12 km al sureste de Minoodasht, en la provincia de Golestán en el norte de Irán. Se recogieron muestras de aguas subterráneas y aguas superficiales aguas arriba y aguas abajo de la mina. Las concentraciones de los elementos se midieron mediante la espectrometría de masa de acoplamiento inductivo (ICP-MS). Los resultados indican que un ambiente alcalino produjo drenaje de minas alcalinas debido a la presencia de la piedra caliza; esto causo altos niveles de pH (8,41) en las fuentes de aguas subterráneas de la zona. La actividad minera incrementó los niveles de concentración de Ba, Cr, Ni, Pb y Zn en las aguas subterráneas de 3,39, 0,5, 0,2, 0,5, 9,2 ppb a 83,52, 2,2, 0,6, 2,6, 48,3 ppb y de 68,7, 0,5, 1,3, 0,8, 172,6 ppb a 91, 1,2, 4,5, 1,3, 27,6 ppb en el agua de la superficie. Debido al ambiente básico, la acumulación de metales pesados en el lecho sedimentario, tanto para los efluentes del tunel como para las aguas de escorrentia, fueron mayores que durante la fase soluble. El pH fue el principal determinante en la solubilidad de los elementos y su distribución en el medio ambiente. El aumento de la concentración de Ba en los recursos hídricos se debió a la alta concentración de Ba en el carbón, carbón de relaves y colas en cantera. Abstract in english The release of heavy metals into the environment represents one of the most important environmental effects involved in extracting coal; it needs to be studied more fully. The present research investigated the effects of coal-mining in an alkaline environment and alkaline mine drainage in the Takht [...] coal mine regarding the distribution of selected heavy metals (Zn, Pb, Ni, Cr and Ba) on the region’s surface and ground water. The mine is located 12 Km southeast of Minoodasht, in Golestan province in northern Iran. Samples were collected from groundwater and surface water resources upstream and downstream of the mine. The elements’ concentrations were measured by the inductively-coupled mass spectrometry (ICPMS) method. The results showed that an alkaline environment was responsible for producing alkaline mine drainage due to the presence of limestone; this caused high pH (8.41) in the area’s groundwater resources. Mining activities increased Ba, Cr, Ni, Pb and Zn concentration in the groundwater from 3.39, 0.5, 0.2, 0.5, 9.2 ppb to 83.52, 2.2, 0.6, 2.6, 48.3 ppb and from 68.7, 0.5, 1.3, 0.8, 172.6 ppb to 91, 1.2, 4.5, 1.3, 27.6 ppb in surface water, respectively. Due to the basic environment, heavy metal accumulation in the bed sediment for both tunnel effluents and runoffs was higher than during the soluble phase. pH was the main controlling factor in elements’ solubility and their distribution in the environment. Increased Ba concentration in water resources was due to high Ba concentration in the coal, coal tailing and in quarry tailings.

  5. Utilização de zeólita preparada a partir de cinza residuária de carvão como adsorvedor de metais em água / Use of zeolite from coal bottom ash as adsorbent of metals from water

    Scientific Electronic Library Online (English)

    Denise Alves, Fungaro; Magali Guilherme da, Silva.

    2002-12-01

    Full Text Available [...] Abstract in english Coal ashes produced in coal-fired power plant could be converted into zeolites and can be used as low-cost adsorbents for the treatment of effluents contaminated with high levels of toxic metals. The capacity of synthetic zeolites for the removal of cadmium, zinc and copper ions from aqueous solutio [...] ns has been investigated under different operating conditions. Zeolite from bottom chimney showed higher removal efficiency for metals ions than zeolite from feed hopper and mixing mill. The results indicated that the treated bottom ash could be applied in environmental technology as an immobilizer of pollutants.

  6. Influence of relative trophic position and carbon source on selenium bioaccumulation in turtles from a coal fly-ash spill site

    International Nuclear Information System (INIS)

    Selenium (Se) is a bioaccumulative constituent of coal fly-ash that can disrupt reproduction of oviparous wildlife. In food webs, the greatest enrichment of Se occurs at the lowest trophic levels, making it readily bioavailable to higher consumers. However, subsequent enrichment at higher trophic levels is less pronounced, leading to mixed tendencies for Se to biomagnify. We used stable isotopes (15N and 13C) in claws to infer relative trophic positions and relative carbon sources, respectively, of seven turtle species near the site of a recently-remediated coal fly-ash spill. We then tested whether Se concentrations differed with relative trophic position or relative carbon source. We did not observe a strong relationship between ?15N and Se concentration. Instead, selenium concentrations decreased with increasing ?13C among species. Therefore, in an assemblage of closely-related aquatic vertebrates, relative carbon source was a better predictor of Se bioaccumulation than was relative trophic position. -- Highlights: •Stable isotope results showed trophic separation among turtle species. •Selenium concentrations did not biomagnify with relative trophic position. •Selenium concentrations decreased with increasing ?13C among species. •Carbon source influenced Se bioaccumulation in an assemblage of related vertebrates. -- Stable isotope differences indicate that claw selenium concentrations differ among relative carbon sources, and not among relative trophic positions, in an assemblage of aquatic turtles

  7. Removal of uranium and gross radioactivity from coal bottom ash by CaCl2 roasting followed by HNO3 leaching

    International Nuclear Information System (INIS)

    Highlight: • Roasting the ash with CaCl2 enhanced the removal of uranium and gross radioactivity. • 87.3% of the total uranium was removed via the optimized roast-leach process. • Nearly 90% of gross ? and ? radioactivity was removed via the roast-leach process. • Molten CaCl2 promoted the incorporation of Ca and Al into Si-O matrices in ash. • Radionuclides were removed by the acid decomposition of newly formed silicates. - Abstract: A roast-leach method using CaCl2 and HNO3 to remove uranium and gross radioactivity in coal bottom ash was investigated. Heat treatment of the ash with 100% CaCl2 (900 °C, 2 h) significantly enhanced uranium leachability (>95%) compared with direct acid-leaching (22.6–25.5%). The removal efficiency of uranium and gross radioactivity increased steeply with increasing CaCl2 content, from 10% to 50%, and a HNO3 leaching time from 5 min to 1 h, but remained nearly constant or decreased slightly with increasing CaCl2 dosage >50% or acid-leaching time >1 h. The majority of the uranium (87.3%), gross ? (92.9%) and gross ? (84.9%) were removed under the optimized roast-leach conditions (50% CaCl2, 1 M HNO3 leaching for 1 h). The mineralogical characteristics of roasted clinker indicated that molten CaCl2 promoted the incorporation of Ca into silica and silicates and resulted in its progressive susceptibility to acid attack. Uranium and other radionuclides, most likely present in the form of silicates or in association with miscellaneous silicates in the highest density fraction (>2.5 g mL?1), were probably leached out as the result of the acid decomposition of newly formed “gelatinizing silicates”

  8. Utilização de zeólita preparada a partir de cinza residuária de carvão como adsorvedor de metais em água Use of zeolite from coal bottom ash as adsorbent of metals from water

    OpenAIRE

    Denise Alves Fungaro; Magali Guilherme da Silva

    2002-01-01

    Coal ashes produced in coal-fired power plant could be converted into zeolites and can be used as low-cost adsorbents for the treatment of effluents contaminated with high levels of toxic metals. The capacity of synthetic zeolites for the removal of cadmium, zinc and copper ions from aqueous solutions has been investigated under different operating conditions. Zeolite from bottom chimney showed higher removal efficiency for metals ions than zeolite from feed hopper and mixing mill. The result...

  9. Preservation of natural aquatic ecosystems by application of bottom coal ash based bioreactor for in situ treatment of anthropogenic effluents

    Science.gov (United States)

    Anker, Y.; Nisnevitch, M.; Tal, M.; Cahan, R.; Michael, E.

    2012-12-01

    One consequence of global climate change is recharge decrease at sub tropical and Mediterranean regions to both the surface and the ground fresh water resources. As a general rule, when water source quantity is reduced, the level of salination, as well as chemical and biological pollutants, tends to increase. The situation is more severe whenever the drainage basin is (a) heavily populated from urban, industrial and agricultural areas, (b) has wide areas of thin or non soil cover and (c) has a karstic structure and morphology. These latter conditions are typical to many regions around the Middle East; whereas pollution hazard to Mid Eastern streams is greater than to those in more humid regions owing to their relative small size and poor dilution capacity. The consequence of this ongoing and increasing anthropogenic pollution is endangerment of natural aquatic habitats and due to decrease in fresh water supply availability also to human sustainability. The ecological impact may involve transition of ephemeral (Wadi) streams into intermittent ones with the accompanied biodiversity change or extinction once the pollution is extreme. The impact on indigenous human communities might be as severe owing to drinking water quality decrease and the consequent decrease id quantity as well as damage to dryland farming. In setting of operations applied to the Yarkon Taninim watershed (central Israel) management, a pilot biofilter facility for sustainable preservation and rehabilitation of natural fluvial ecosystems was tested. This biofilter is planned to operate through low impact concept assimilating natural treatment processes occurring during runoff recharge through a porous flow media. The facility is constructed out of several grain sizes of bottom coal ash aggregate, which was found to be a better microbial mats growing stratum, compared to common natural aggregates such as tuff and lime pebbles (and also has an EPA directive for wastewater treatment). The biofilter is operating with initial horizontal flow and continuous vertical circulation through aeration apparatus. Along the flow path several different bio-modules are applied, the sequence consists of aerobic and anaerobic stages, as well as biomass preservation section and fine grain filtration. The pilot biofilter facility was built during the summer of 2009; the influent consisted of domestic wastewater (of the adjacent Ariel University dormitories) and also synthetic aquatic solutions equivalent to urban, industrial, and roads runoff effluents. The biofilter operation evaluation demonstrated significant decrease in pollution loads, including organic, salts and pathogens. The facility's efficiency reached approximately 90% reduction or more, allowing the release of treated runoff without limitation to natural fluvial ecosystems (according to the required regulations). The present stage in the project is implementation of the method and process by application of a full scale pilot facility at a joint between an anthropogenic drainage network, consisting of urban, industrial and motorway runoff collection systems and a typical natural Samaritan fluvial ecosystem. The purpose of the system is to treat these anthropogenic effluents prior to their release into the stream and by that to prevent the negative environmental above mentioned effects.

  10. Adsorção de nitrogênio amoniacal de efluentes industriais pela zeólita Na-P1 sintetizada a partir da cinza pesada de carvão mineral / Ammoniacal nitrogen adsorption of industrial effluent by zeolite Na-P1 synthesized from coal bottom ash

    Scientific Electronic Library Online (English)

    Alexandre, Wasem; Sabrine Cássia, Bôer; Sydney, Sabedot; Ana Cristina Borba da, Cunha.

    2015-03-01

    Full Text Available A legislação ambiental em vigor impõe padrões de emissões cada vez mais restritivos às indústrias geradoras de efluentes. Considerando essas exigências, as empresas precisam se adequar a essas políticas, tornando seus processos produtivos mais eficazes e menos poluentes. A combustão de carvão minera [...] l em usinas termoelétricas gera cinzas pesadas que retornam aos produtores do insumo mineral e constituem um passivo ambiental. Neste estudo, as cinzas pesadas foram utilizadas para testes na síntese hidrotérmica (Hidrogel), em meio alcalino, visando à formação de zeólita Na-P1. Para comprovar a sua efetiva formação, foram realizadas análises por difração de raios X, fluorescência de raios X e capacidade de troca catiônica com solução padrão de cloreto de amônio, cujo valor em termos de equivalentes foi de 23,7 mg g-1. Os resultados comprovaram a formação da zeólita Na-P1. Foram avaliados três efluentes industriais de três empresas distintas. A concentração final de nitrogênio amoniacal encontrada para os três efluentes após testes de adsorção de amônio em reator de leito fluidizado apresentaram uma redução de 49% ± 2 e os valores obtidos em termos de equivalentes foram de 21,8 mg g-1, 22,9 mg g-1 e 22,7 mg g-1. As Resoluções CONAMA 357/2005 430/2011 determinam padrões de qualidade de águas para diversas substâncias; no caso da amônia é de 20 mg L-1 de N/NH3. Considerando a grande dificuldade para reduzir os teores de nitrogênio amoniacal em determinados efluentes industriais, novas tecnologias vêm sendo implantadas, como a síntese de zeólitas a partir das cinzas pesadas de carvão. Esse estudo comprovou que a zeólita Na-P1 tem um grande potencial de adsorção para a redução de nitrogênio amoniacal de efluentes industriais. Abstract in english Environmental legislation in the country always requires more stringent standards for effluent generating industries. Companies must adapt to these laws making the industrial processes more efficient and less polluting. Burning coal in power plants produces bottom ash. This material returns to the c [...] oal producers and constitutes an environmental liability to the company. In this study, bottom ash was used in tests for the hydrothermal synthesis, under alkaline conditions, to generate zeolite Na-P1. Analyses by X-ray diffraction, X-ray fluorescence and cation exchange capacity with standard solution of ammonium chloride confirmed to the generation of zeolite Na-P1, and the value of the cation exchange capacity of the equivalent was 23.7 mg g-1. Three industrial effluents from three different companies were collected and evaluated. Tests for ammonia adsorption in a fluidized bed reactor were performed in the three effluents. The results for the final ammonia concentration showed a reduction of 49% ±2, and the values obtained are in terms of equivalent of 21.8 mg g-1, 22.9 mg g-1 e 22.7 mg g-1. CONAMA Resolution numbers 357/2005 and 430/2011 determining values for water quality standards to the various substances. The value for ammonia is 20 mg L-1 N/NH3. Considering the difficulties to reduce the ammonia nitrogen concentration in certain industrial effluents, new technologies are being implemented, such as the synthesis of zeolite from coal bottom ash. This study showed that zeolite Na-P1 has good potential for adsorption to reduce the ammonia nitrogen content from industrial effluents.

  11. Coal

    International Nuclear Information System (INIS)

    Coal world production represents 3.5 billions of tons, plus 900 millions of tons of lignite. 50% of coal is used for power generation, 16% by steel making industry, 5% by cement plants, and 29% for space heating and by other industries like carbo-chemistry. Coal reserves are enormous, about 1000 billions of tons (i.e. 250 years of consumption with the present day rate) but their exploitation will be in competition with less costly and less polluting energy sources. This documents treats of all aspects of coal: origin, composition, calorific value, classification, resources, reserves, production, international trade, sectoral consumption, cost, retail price, safety aspects of coal mining, environmental impacts (solid and gaseous effluents), different technologies of coal-fired power plants and their relative efficiency, alternative solutions for the recovery of coal energy (fuel cells, liquefaction). (J.S.)

  12. The chemical enhancement of the triboelectric separation of coal from pyrite and ash: A novel approach for electrostatic separation of mineral matter from coal

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, R.M.; DiMare, S.; Sabatini, J.

    1992-02-01

    Arthur D. Little, Inc., under contract to the US DOE Pittsburgh Energy Technology Center, has developed a triboelectric separation device for coal beneficiation, that employs an entrained-flow, rotating-cylinder concept. The described apparatus has been used to test the efficacy of chemical pretreatment and in-situ treatment of coal on separation efficiency. Coal particle entrainment is achieved with gaseous carbon dioxide and particle collection is accomplished by an electrostatic plate separator. The triboelectric separation device incorporates instrumentation for the direct measurement of charge in the dilute-phase particle stream. Some of the pretreatment materials investigated under this project to modify the surface charging characteristics of the coal included oleic acid, sodium oleate, quinoline and dicyclohexylamine. Ammonia and sulfur dioxide at a concentration up to 1000 ppM was used for in-situ treatment of the coal, with carbon dioxide as the carrier/inerting gas. Nitrogen was used earlier in the test program as the carrier/inerting gas for the coal, but a severe arcing problem was encountered in the electrostatic collector with nitrogen as the carrier gas. This problem did not occur when carbon dioxide was used. The report covers the chemical treatment employed, and summarizes and interprets the results achieved. In addition, an economic analysis of a full scale system based on this concept is presented.

  13. The chemical enhancement of the triboelectric separation of coal from pyrite and ash: A novel approach for electrostatic separation of mineral matter from coal. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, R.M.; DiMare, S.; Sabatini, J.

    1992-02-01

    Arthur D. Little, Inc., under contract to the US DOE Pittsburgh Energy Technology Center, has developed a triboelectric separation device for coal beneficiation, that employs an entrained-flow, rotating-cylinder concept. The described apparatus has been used to test the efficacy of chemical pretreatment and in-situ treatment of coal on separation efficiency. Coal particle entrainment is achieved with gaseous carbon dioxide and particle collection is accomplished by an electrostatic plate separator. The triboelectric separation device incorporates instrumentation for the direct measurement of charge in the dilute-phase particle stream. Some of the pretreatment materials investigated under this project to modify the surface charging characteristics of the coal included oleic acid, sodium oleate, quinoline and dicyclohexylamine. Ammonia and sulfur dioxide at a concentration up to 1000 ppM was used for in-situ treatment of the coal, with carbon dioxide as the carrier/inerting gas. Nitrogen was used earlier in the test program as the carrier/inerting gas for the coal, but a severe arcing problem was encountered in the electrostatic collector with nitrogen as the carrier gas. This problem did not occur when carbon dioxide was used. The report covers the chemical treatment employed, and summarizes and interprets the results achieved. In addition, an economic analysis of a full scale system based on this concept is presented.

  14. Synthesis and characterization of zeolite from coal ashes modified by cationic surfactant; Sintese e caracterizacao de zeolita de cinzas de carvao modificada por surfactante cationico

    Energy Technology Data Exchange (ETDEWEB)

    Fungaro, D.A.; Borrely, S.I., E-mail: dfungaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-01-15

    Zeolite synthesized from coal fly ash was modified with different concentrations (2 and 20 mmol.L{sup -1}) of hexadecyltrimethylammonium bromide (HDTMA-Br). The Non-Modified Zeolite (NMZ) and Surfactant-Modified Zeolites (SMZ) were characterized by X-ray fluorescence spectrometry, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, thermogravimetric analysis, among others. The SMS presented negative charge probably due to the formation of a partial bilayer of HDTMA on exchangeable active sites on the external surface of NMZ. A decrease in surface area was observed for SMZ as compared to NMZ indicating zeolite surface coverage with HDTMA-Br molecules. The crystalline nature of the zeolite remained intact after adsorption of surfactant and heating for drying. FTIR analysis indicated that there were no significant changes in the structure of the zeolite after adsorption of surfactant. (author)

  15. Impact of Coal Fly Ash Addition on Combustion Aerosols (PM2.5) from Full-Scale Suspension-Firing of Pulverized Wood

    DEFF Research Database (Denmark)

    DamØ, Anne Juul; Wu, Hao

    2014-01-01

    The formation of combustion aerosols was studied in an 800 MWth suspension-fired power plant boiler, during combustion of pulverized wood pellets with and without addition of coal fly ash as alkali capture additive. The aerosol particles were sampled and characterized by a low-pressure cascade impactor (LPI), and elemental composition and particle morphology was studied by electron microscopy methods (SEM/EDS and TEM/EDS). During pulverized wood combustion, the mass-load of submicrometer particles (PM1) was in the range 44–47 mg/Nm3, and the mass-based particle size distribution revealed a distinct submicrometer peak located around 0.2 ?m. This peak consisted mainly of aggregated ultrafine (

  16. Effect of several elements on coal ash corrosion rate of Ni-base alloys. Development of boiler tubing alloy for advanced coal fired boiler (I)

    Energy Technology Data Exchange (ETDEWEB)

    Yamanouchi, N.; Tamura, M.

    1986-01-01

    The tubing of superheaters and reheaters is subject to corrosion by molten ash. The authors report the development of an alloy based on 30%Cr-50%Ni-balance Fe. After melting, rolling, machining, heat treatment and descaling, samples were coated in synthetic ash (25%Fe/sub 2/O/sub 3/ - 41%K/sub 2/SO/sub 4/ - 34%Na/sub 2/SO/sub 4/), heated to 600-800 C and held in simulated combustion gas (1%SO/sub 2/ - 5%O/sub 2/ - 15%CO/sub 2/ - balance N/sub 2/) for 100 hours. Corrosion was found to be promoted by Mo, Al, Ti and Nb, and retarded by Si, Mn and Ce. C, Zr, P and S had no apparent effect on corrosion. 2 references, 2 figures.

  17. Study of the Analytical Conditions for the Determination of Cadmium in Coal Fly Ashes by GFAAS with evaluation of several matrix modifiers

    International Nuclear Information System (INIS)

    A new method for the determination of cadmium in coal fly ash samples by Graphite Furnace Atomic Absorption Spectrometry (GFAAS) has been developed. Analytical conditions and different instrumental parameters have been optimized. In a first step, several types of matrix modifiers have been tested and a mixture of 2% NH4H2PO4 with 0.4%Mg(NO3)2 in 0.5N HNO3 has been selected, since it provides the highest sensitivity. In a second step, an optimization of several conditions, using the selected modifier, has been carried out, such as ashing and atomization temperatures, heating rate, etc. The influence of the use of a L' vov platform on the analytical and background signals has been studied, showing a significative decrease on the background signal, being the net absorbance similar to those obtained in absence of the platform. Using the optimal conditions, the direct method with standard samples provides cadmium concentration consistent with those obtained using the standard addition method. (Author) 18 refs

  18. Advanced development of a pressurized ash agglomerating fluidized-bed coal gasification system: Topical report, Process analysis, FY 1983

    Energy Technology Data Exchange (ETDEWEB)

    None

    1987-07-31

    KRW Energy Systems, Inc., is engaged in the continuing development of a pressurized, fluidized-bed gasification process at its Waltz Mill Site in Madison, Pennsylvania. The overall objective of the program is to demonstrate the viability of the KRW process for the environmentally-acceptable production of low- and medium-Btu fuel gas from a variety of fossilized carbonaceous feedstocks and industrial fuels. This report presents process analysis of the 24 ton-per-day Process Development Unit (PDU) operations and is a continuation of the process analysis work performed in 1980 and 1981. Included is work performed on PDU process data; gasification; char-ash separation; ash agglomeration; fines carryover, recycle, and consumption; deposit formation; materials; and environmental, health, and safety issues. 63 figs., 43 tabs.

  19. Ash management of thermal power plant: a case study

    International Nuclear Information System (INIS)

    Stage-I of the Talcher Thermal Power Station (TTPS) consists of 4 coal-fired units each of 625 MW capacity. TTPS uses coal from Talcher coal field. The coal has a high silica content and hence high quantity of ash. At full capacity the plant will generate 1920 tonnes of ash per day, but due to plant load factor its generation is less. Of the ash generated, 20% is bottom ash and 80% is fly ash. The furnace bottom ash is collected in water filled ash hoppers and is periodically discharged for transfer through transport line once in every 8 hours to ash slurry sump. The fly ash is collected in dry free flowing form by electrostatic precipitators. Fly ash collected in fly ash hoppers is carried to a collecting tank where it is mixed with water to form slurry. The ash slurry is carried through a pipe at an average rate of 1600 tonnes per day to an ash pond of 36 acres area. The pond collects the ash by settling process. The present area of the ash pond is grossly inadequate. It is recommended that the ash should be utilised as a filling material for mined out coal fields which are located nearby and therefore, same transportation (conveyor system) can be used for both feeding coal to power station and feeding ash to the open cast mines. (M.G.B.). 5 refs

  20. Ecophysiological and biochemical traits of three herbaceous plants growing on the disposed coal combustion fly ash of different weathering stage

    OpenAIRE

    Gaji? Gordana; Pavlovi? P.; Kosti? Olga; Jari? Snežana; ?ur?evi? Lola; Pavlovi? Dragana; Mitrovi? Miroslava

    2013-01-01

    The ecophysiological and biochemical traits of Calamagrostis epigejos (Roth.) Festuca rubra L. and Oenothera biennis L. growing on two fly ash lagoons of different weathering stage (L1-3 years and L2-11 years) of the “Nikola Tesla- A” thermoelectric plant (Obrenovac, Serbia) were studied. Species-dependent variations were observed at the L1 lagoon; the greatest vitality (Fv/Fm and Fm/Fo) followed by higher photopigment and total phenolic contents were measu...

  1. A seasonal assessment of the impact of coal fly ash disposal on the River Yamuha, Delhi. II. Biology

    International Nuclear Information System (INIS)

    The impact of fly ash on the biology of the Yamuna River, Delhi, was studied. Effluent come from a 200 MW capacity I.P. thermal power station. Seasonal variations in biological features in the non-impacted (Y-1) and the impacted (Y-2) segments of the river receiving fly ash effluents were studied. 60 genera of phytoplankton including 29 Chlorophyceae, 19 Bacillariophyceae, 8 Cyanobacteria, and 4 Egulenophyceae were recorded. Phytoplankton diversity was reduced at the impacted site in comparison to the non-impacted site of the river and substantial changes in the composition of various groups inhabiting these areas were observed. Zooplankton were also reduced at Y-2 compared to Y-1, especially rotifers and protozoans, while copepods and nauplii larvae were not affected to the same degree. Species diversity was not significantly different at Y-2 and Y-1 but similarity index varied from low to high between the two stations. Thus, not only was the density, number of genera and diversity reduced, even the generic composition of the plankton was markedly affected in the impacted waters. The observed perturbations could be due to sedimentation of ash particles, pH or elevated metal or salt concentration. A change in the concentration of one or more constituents disturbs the relationship between biota and could be the possible cause of reduced densities in the impacted waters. 56 refs., 10 figs., 4 tabs

  2. Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary

    Energy Technology Data Exchange (ETDEWEB)

    Cavallaro, J.A.; Deurbrouck, A.W.; Killmeyer, R.P.; Fuchs, W. (USDOE Pittsburgh Energy Technology Center, PA (USA). Coal Preparation Div.); Jacobsen, P.S. (Burns and Roe Services Corp., Pittsburgh, PA (USA))

    1991-02-01

    This report presents the washability and comprehensive characterization results of 184 raw coal channel samples, including anthracite, bituminous and lignite coals, collected from the Central Region of the United States. This is the second of a three volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and an in-depth characterization of each sample are presented alphabetically by state in Appendix C. In Appendix D, a statistical evaluation is given for the composited washability data, selected chemical and physical properties and washability data interpolated at various levels of Btu recovery. This presentation is shown by state, section, and region where four or more samples were collected. Appendix E presents coalbed codes and names for the Central Region coals. Graphical summations are presented by state, section and region showing the effects of crushing on impurity reductions, and the distribution of raw and clean coal samples meeting various levels of SO{sub 2} emissions. 35 figs., 5 tabs.

  3. Determination of technologically enhanced naturally occurring radioactive material (TENORM) in ashes from coal-fired thermal power plants in the Philippines

    International Nuclear Information System (INIS)

    The activity concentration (AC) of TENORM - 238U, 226Ra (238U series), 232Th, 228Ra, 228Th (232Th series) and 40K in feed coal, bottom ash and fly ash samples from four coal-fired thermal power plants C, M, P and S were determined using two techniques: inductively coupled plasma mass spectrometry (ICP-MS) and high purity germanium (HPGe) gamma spectrometry. For 232Th and 238U [determined at National Institute for Radiological Sciences (NIRS) by the ICP-MS)], Plant S feed coal (FC) sample that originated from China had the highest AC (15.77 ± 0.32 Bq/kg and 13.67 ± 0.82 Bq/kg, respectively), followed by Plant M FC sample also from China (8.31 ± 0.33 Bq/kg and 5.84 ± 0.12 Bq/kg, respectively), while Plants C and P FC samples that originated from the Philippines and Indonesia had the lowest ACs of 232Th and 238U. Plant S also had the highest bottom ash (BA) AC of 80.86 ± 3.23 Bq/kg and 100.20 ± 4.01 Bq/kg, respectively while Plant P had the highest fly ash (FA) AC of 155.96 ± 6.24 Bq/kg and 268.03 ± 10.72 Bq/kg, respectively. For AC's of 226Ra, 228Ra, 228Th and 40K determined by NIRS HPGe, Plant C had the highest in the FC sample (11.70 ± 1.39 Bq/kg, 13.65 ± 4.99 Bq/kg, 11.35 ± 3.96 Bq/kg ad 80.23 ± 10.91 Bq/kg, respectuvely). For AC's in the BA samples, Plant M had the highest 226Ra (106.73 ± 6.74 Bq/kg) and Plant S had the highest 228Ra and 40K (66.64 ± 8.16 Bq/kg and 400.93 ± 43.06 Bq/kg, respectively For AC's in the FA samples, Plant S had the highest 226Ra and228Ra AC's (131.13 ± 8.09 Bq/kg and 87.70 ± 10.45 Bq/kg, respectively) while Plant C had the highest 40K AC (369.08 ± 40.87 Bq/kg). The highest AC enhancement of 238U, 226Ra (238U series), 232Th,228Ra, 228Th (232Th series) 40K relative to feed coal occurred in Plant P FA sample, with 238U showing the highest enhancement of 93.72 among the radionuclides. When normalized with 40K, 238U in Plant P FA sample also had the highest enrichment factor (EF). Except for Plant C samples, 228Ra, 228Th and 40K were about equallypartitioned between BA and FA samples; 238U had consistently higher partitioning in all FA samples than BA samples; 226Ra and 232Th had varied partitioning behavior among the Plants' BA and FA samples. The behavior of the radionuclides during combustion was explained to be influenced by their physical and chemical characteristics and their association with the alumino-silicate minerals in the coal. For most samples, positive correlations between NIRS ICP-MS and NIRS HPGe were very high for 226Ra with 238U (R2=0.98), and 228Ra with 232Th (R2=0.94). Correspondence between ICP-MS and HPGe results were generally high with slopes of 0.90 and zero intercept for both 226Ra vs 238U and 228Ra vs 232Th. Correlations between NIRS HPGe and PNRI HPGe were also very high for 226Ra (R2=0.93) and 228Ra (R2=0.91), and high for 40K (R2=0.86). However the slopes of the correlation lines gave only 0.65 to 0.68 correspondence of NIRS HPGe relative to PNRI HPGe. This could be attribute to the slight difference in sample and standard geometry used in PNRI HPGe experiment and different multi-channel analyzer emulation software used by NIRS and PNRI HPGe's. The result of more detailed study in Plant C showed that the ACs of 226Ra, 228Ra, and 40K were similar between two sampling periods in 2005 and 2006; the ACs in the ash pond were generally slightly lower than that in the BA and FA samples; and the ACs showed a slight decreasing trend with ash pond depth. The AC in both BA and FA samples from Plants C, M, P and S were all below the International Atomic Energy Agency (IAEA) and European Commission (EC) recommended AC levels for regulatory control. The absorbed gamma dose rates in air inside Plant C ranged from29-36 nGy/h; in its vicinity (adjacent agricultural, public and residential areas) 27-41 nGy/h; and in the pond, 44-56 Gy/h. These were within the reported dose rates in Marinduque, Batan Island, and worldwide average in UNSCEAR. Based on the AC values in FA samples from Plant C, the estimted discharges of radionuclides from the stacks were lower compared

  4. Effects of coal fly ash on the rheological characteristics of concrete paste and mortar; Zum Einfluss von Steinkohlenflugaschen auf das rheologische Verhalten von Zementleimen und -moerteln

    Energy Technology Data Exchange (ETDEWEB)

    Freimann, T.

    2002-07-01

    For the placement of concrete at a building site the workability of the fresh concrete is one of the most important influence parameters. The workability is depending on the internal forces within the suspension and interactions between the solid particles. Particularly the paste and mortar phase and thus the sort and composition of fine constituents influence decisively the flowability of the fresh concrete. In addition to cement often fly ashes (FA) are used as fine components in concrete. Not only the properties of the hardened concrete are changed by the addition of FA but also the rheological properties of the fresh mortar and paste. In this study the most important parameters of the basic ingredients regarding the flowability were determined on the basis of experiments with cement/FA-pastes and mortars with a maximum particle size of 2 mm. General statements about the effect, respectively the application of FA were formulated. At the main part experiments were performed using the rotational viscometer (Viskomat) in order to determine the yield value and plastic viscosity according to the Bingham model. For cement/FA-suspensions the influence of the FA on the internal forces is presented and compared between pastes and mortars. The addition of FA influences the yield value as well as the plastic viscosity of the suspension. With the aid of multiple linear regression analysis the material parameters were determined which are most important for the rheological properties. Several numerical equations were derived permitting an estimation of yield value and viscosity of various cement/FA-suspensions. For practical use a nomogram was developed which allows a rapid estimation of the rheological behaviour for different fly ashes. The results of the investigation showed that an appropriate parameter to describe FA-influence on the flowability is the water demand determined by EN 196 with the same procedure as for cement (required amount of water in Vol.-% for normal stiffening of the paste). Addition of coal fly ashes with low water demand in most cases improves the workability of mortar suspensions. Fly ashes with high water demands reduces the consistency. (orig.)

  5. Trace element partitioning behavior of coal gangue-fired CFB plant: experimental and equilibrium calculation.

    Science.gov (United States)

    Zhang, Yingyi; Nakano, Jinichiro; Liu, Lili; Wang, Xidong; Zhang, Zuotai

    2015-10-01

    Energy recovery is a promising method for coal gangue utilization, during which the prevention of secondary pollution, especially toxic metal emission, is a significant issue in the development of coal gangue utilization. In the present study, investigation into trace element partitioning behavior from a coal gangue-fired power plant in Shanxi province, China, has been conducted. Besides the experimental analysis, thermodynamic equilibrium calculation was also conducted to help the further understanding on the effect of different parameters. Results showed that Hg, As, Be, and Cd were highly volatile elements in the combustion of coal gangue, which were notably enriched in fly ash and may be emitted into the environment via the gas phase. Cr and Mn were mostly non-volatile and were enriched in the bottom ash. Pb, Co, Zn, Cu, and Ni were semi-volatile elements and were enriched in the fly ash to varying degrees. Equilibrium calculations show that the air/fuel ratio and the presence of Cl highly affect the element volatility. The presence of mineral phases, such as aluminosilicates, depresses the volatility of elements by chemical immobilization and competition in Cl. The coal gangue, fly ash, and bottom ash all passed the toxicity characteristic leaching procedure (TCLP), and their alkalinity buffers the acidity of the solution and contributes to the low solubility of the trace elements. PMID:26006077

  6. Ashes to ashes?

    Energy Technology Data Exchange (ETDEWEB)

    Malcolm, Len; Rossen, A. van [ECNZ Central Generation (New Zealand)

    1997-02-01

    In September 1995 the turbines and auxiliary systems of the Rangipo power station in New Zealand were extensively damaged by volcanic ash from Mount Ruapehu`s volcano deposited in the fast flowing waters of the Tongariro River. This article describes the modifications which have been made to the turbines and auxiliaries to protect them from volcanic ash. (UK)

  7. Coal

    International Nuclear Information System (INIS)

    It is estimated that World coal trade remained strong during the second quarter of 1991, with contributing factors including unseasonally large shipments to Japan for power generation, sustained Japanese steel production at around 112 Mt and some buildup in stocks in that country. Purchases by North Asian and European consumers also remained high. At the same time Soviet output and exports declined because of strikes and political unrest. In addition, exportable supplies in Poland fell. As a result the demand for Indonesian coal increased, and Australia exported larger than previously expected quantities of coal. ills

  8. Application of the electrical characterization to the study of the hydrated phases of the cement with coal bottom ash

    International Nuclear Information System (INIS)

    The present paper investigates the influence of using Bottom and Fly Ash as partial replacement of cement in the hydration process. Through measurements of electrical impedance spectroscopy (EIS) and X -ray diffraction (XRD), we analyze from the early stages to the hydration process to the end. Values of EIS, XRD and its relation, are used to determine transformation of hydrated phases, and for each of the substitutions, is indicated as modified the hydrated phase as a function of time and compared it with the reference material. It also proves the relevance of using EIS measures in real time, and as non destructive testing to characterize the hydration process of these materials. (Author)

  9. Analytical investigation of lignite and its ash samples taken from the Afsin-Elbistan coal basin in Turkey

    International Nuclear Information System (INIS)

    Lignite, taken from basin in Afsin-Elbistan region, and ash samples were analyzed according to the qualitative, quantitative and radioactivity properties. An elemental analysis was made by using the Energy Dispersive X-Ray Fluorescence (EDXRF) technique. 59.5 keV photons emitted from a 241Am source and 5.9 keV photons emitted from a 55Fe radioactive source were used for excitation. The characteristic K X-rays of the elements were counted with a Si(Li) detector. For the same samples gross alpha, gross beta and radionuclide activities were also measured. (orig.)

  10. Technology for the Recovery of Fuel and Adsorbent Carbons from Coal Burning Utility Ash Ponds and Landfills

    Energy Technology Data Exchange (ETDEWEB)

    J.G. Groppo; T.L. Robl

    2005-09-30

    Several sampling techniques were evaluated to recover representative core samples from the ash ponds at Western Kentucky Energy's Coleman Station. The most successful was a combination of continuous-flight augers and specially designed soft-sediment sampling tubes driven by a Hammerhead drill mounted on an amphibious ARGO vehicle. A total of 51 core samples were recovered and analyzed in 3 ft sections and it was determined that there are 1,354,974 tons of ash in Pond C. Of the over 1.35M tons of ash present, 14% or 190K tons can be considered as coarse (+100 mesh). Pond C contains approximately 88K tons of carbon, nearly half of which is coarse and potentially recoverable with spiral concentration while the fine carbon (-100 mesh) is recoverable with froth flotation. There are 1.27M tons of carbon-free ash, 12% of which is coarse and potentially usable as block sand. Spiral concentration testing on bulk samples showed that product grade of 30 to 38% C (4200 to 5500 Btu/lb) was obtainable. When this product was cleaned again in an additional stage of spiral concentration, the product grade was improved to 7200 to 8200 Btu/lb with an accompanying 13 to 29% decrease in yield. Release analysis of hydraulically classified pond ash showed that froth flotation could provide froth products with as high a grade as 9000 Btu/lb with a yield of 5%. Increasing yield to 10% reduced froth grade to 7000 Btu/lb. Batch flotation provided froth grades as high as 6500 Btu/lb with yields of 7% with 1.5 lb/ton SPP and 1 lb/ton frother. Column flotation test results were similar to those achieved in batch flotation in terms of both grade and yield, however, carbon recoveries were lower (<70%). High airflow rate was required to achieve >50% carbon recovery and using wash water improved froth grade. Bottom ash samples were recovered from each of the units at Coleman Station. Characterization confirmed that sufficient quantity and quality of material is generated to produce a marketable lightweight aggregate and recover a high-grade fuel product. Spiral concentration provided acceptable grade lightweight aggregate with yields of only 10 to 20%. Incorporating a sieve bend into the process to recover coarse, porous ash particles from the outside race of the spirals increased aggregate yield to as high as 75%, however, the carbon content of the aggregate also increased. An opening size of 28 mesh on the sieve bend appeared to be sufficient. Lightweight concrete blocks (28 to 32 lbs) were produced from bottom ash and results show that acceptable strength could be attained with a cement/concrete ratio as low as 1/4. A mobile Proof-of-Concept (POC) field unit was designed and fabricated to meet the processing objectives of the project. The POC plant consisted of two trailer-mounted modules and was completely self sufficient with respect to power and water requirements. The POC unit was hauled to Coleman Station and operated at a feed rate of 2 tph. Results showed that the spirals operated similarly to previous pilot-scale operations and a 500 lb composite sample of coarse carbon was collected with a grade of 51.7% C or 7279 Btu/lb. Flotation results compared favorably with release analysis and 500 lbs of composite froth product was collected with a grade of 35% C or 4925 Btu/lb. The froth product was dewatered to 39% moisture with vacuum filtration. Pan pelletization and briquetting were evaluated as a means of minimizing handling concerns. Rotary pan pelletization produced uniform pellets with a compressive strength of 4 lbf without the use of any binder. Briquettes were produced by blending the coarse and fine carbon products at a ratio of 1:10, which is the proportion that the two products would be produced in a commercial operation. Using 3% lime as a binder produced the most desirable briquettes with respect to strength, attrition and drop testing. Additionally, the POC carbon products compared favorably with commercial activated carbon when used for removal of mercury from simulated flue gas. A business model was generated to summarize

  11. Ecophysiological and biochemical traits of three herbaceous plants growing on the disposed coal combustion fly ash of different weathering stage

    Directory of Open Access Journals (Sweden)

    Gaji? Gordana

    2013-01-01

    Full Text Available The ecophysiological and biochemical traits of Calamagrostis epigejos (Roth. Festuca rubra L. and Oenothera biennis L. growing on two fly ash lagoons of different weathering stage (L1-3 years and L2-11 years of the “Nikola Tesla- A” thermoelectric plant (Obrenovac, Serbia were studied. Species-dependent variations were observed at the L1 lagoon; the greatest vitality (Fv/Fm and Fm/Fo followed by higher photopigment and total phenolic contents were measured in O. biennis in relation to C. epigejos (p<0.001 and F. rubra (p<0.001. At the L2 site, higher vitality was found in O. biennis (p<0.001 and F. rubra (p<0.01 compared to C. epigejos. O. biennis had the highest photosynthetic capacity. The results obtained in this study indicate that all examined species maintained a level of photosynthesis that allowed them to survive and grow under the stressful conditions in ash lagoons, albeit with lower than optimal success. [Projekat Ministarstva nauke Republike Srbije, br. 173018

  12. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  13. Fly ash leachate generation and qualitative trends at Ohio test sites

    Energy Technology Data Exchange (ETDEWEB)

    Solc, J.; Foster, H.J.; Butler, R.D. [Energy & Environmental Research Center, Grand Forks, ND (United States)

    1995-12-01

    Under the sponsorship of the U.S. Department of Energy, the environmental impact and potential contamination from landfilled fly ash (coal conversion solid residues - CCSRs) have been studied at field sites in Ohio. The progressive increase of moisture content within pilot cells over depth and time facilitated intensive chemical processes and generation of highly alkaline (pH of 10 to 12) leachate. Chemistry of pore water from lysimeters and ASTM leachate from fly ash and soil cores indicate the leachate potential to migrate out of deposit and impact the pore water quality of surrounding soils. Na, SO{sub 4} and, particularly, K, Cl, pH, and EC appeared to be valuable indicator parameters for tracking potential leachate transport both within the cells and below the ash/soil interface.

  14. Remedial Investigation Report on Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond/Upper McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 1. Main Text

    International Nuclear Information System (INIS)

    This document is a report on the remedial investigation (RI) of Chestnut Ridge Operable Unit (OU) 2 at the Oak Ridge Y-12 Plant. Chestnut Ridge OU 2 consists of Upper McCoy Branch (UMB), the Filled Coal Ash Pond (FCAP), and the area surrounding the Sluice Channel formerly associated with coal ash disposal in the FCAP. Chestnut Ridge OU 2 is located within the U.S. Department of Energy's (DOE's) Oak Ridge Reservation in Anderson County, Tennessee, approximately 24 miles west of Knoxville. The pond is an 8.5-acre area on the southern slope of Chestnut Ridge, 0.5 mile south of the main Y-12 Plant and geographically separated from the Y-12 Plant by Chestnut Ridge. The elevation of the FCAP is ? 950 ft above mean sea level (msl), and it is relatively flat and largely vegetated. Two small ponds are usually present at the northeast and northwest comers of the FCAP. The Sluice Channel Area extends ?1000 ft from the northern margin of the FCAP to the crest of Chestnut Ridge, which has an elevation of ?1100 ft above msl. The Sluice Channel Area is largely vegetated also. McCoy Branch runs from the top of Chestnut Ridge across the FCAP into Rogers Quarry and out of the quarry where it runs a short distance into Milton Hill Lake at McCoy Embayment, termed UMB. The portion south of Rogers Quarry, within Chestnut Ridge OU 4, is termed Lower McCoy Branch. The DOE Oak Ridge Y-12 Plant disposed of coal ash from its steam plant operations as a slurry that was discharged into an ash retention impoundment; this impoundment is the FCAP. The FCAP was built in 1955 to serve as a settling basin after coal ash slurried over Chestnut Ridge from the Y-12 Plant. The FCAP was constructed by building an earthen dam across the northern tributary of McCoy Branch. The dam was designed to hold 20 years of Y-12 steam plant ash. By July 1967, ash had filled up the impoundment storage behind the dam to within 4 ft of the top

  15. Remedial Investigation Report on Chestnut Ridge Operable Unit 2 (Filled Coal Ash Pond/Upper McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 1. Main Text

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    This document is a report on the remedial investigation (RI) of Chestnut Ridge Operable Unit (OU) 2 at the Oak Ridge Y-12 Plant. Chestnut Ridge OU 2 consists of Upper McCoy Branch (UMB), the Filled Coal Ash Pond (FCAP), and the area surrounding the Sluice Channel formerly associated with coal ash disposal in the FCAP. Chestnut Ridge OU 2 is located within the U.S. Department of Energy`s (DOE`s) Oak Ridge Reservation in Anderson County, Tennessee, approximately 24 miles west of Knoxville. The pond is an 8.5-acre area on the southern slope of Chestnut Ridge, 0.5 mile south of the main Y-12 Plant and geographically separated from the Y-12 Plant by Chestnut Ridge. The elevation of the FCAP is {approximately} 950 ft above mean sea level (msl), and it is relatively flat and largely vegetated. Two small ponds are usually present at the northeast and northwest comers of the FCAP. The Sluice Channel Area extends {approximately}1000 ft from the northern margin of the FCAP to the crest of Chestnut Ridge, which has an elevation of {approximately}1100 ft above msl. The Sluice Channel Area is largely vegetated also. McCoy Branch runs from the top of Chestnut Ridge across the FCAP into Rogers Quarry and out of the quarry where it runs a short distance into Milton Hill Lake at McCoy Embayment, termed UMB. The portion south of Rogers Quarry, within Chestnut Ridge OU 4, is termed Lower McCoy Branch. The DOE Oak Ridge Y-12 Plant disposed of coal ash from its steam plant operations as a slurry that was discharged into an ash retention impoundment; this impoundment is the FCAP. The FCAP was built in 1955 to serve as a settling basin after coal ash slurried over Chestnut Ridge from the Y-12 Plant. The FCAP was constructed by building an earthen dam across the northern tributary of McCoy Branch. The dam was designed to hold 20 years of Y-12 steam plant ash. By July 1967, ash had filled up the impoundment storage behind the dam to within 4 ft of the top.

  16. Kinetics of batch alkylation of phenol with tert-butyl alcohol over a catalyst synthesized from coal fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Ojha, K.; Pradhan, N.C.; Samanta, A.N. [Indian Institute of Technology, Kharagpur (India). Dept. of Chemical Engineering

    2005-09-01

    Alkylation of phenol with tert-butyl alcohol (TBA) was carried out in batch mode over a zeolite