WorldWideScience

Sample records for cement kiln dust

  1. CEMENT KILN DUST AS A MATERIAL FOR BUILDING BLOCKS ...

    This paper presents the results of a study on the properties of hollow sandcrete blocks with cement kiln dust (CKD) as an additive and as a replacement for ordinary portland cement (OPC). When CKD was used as a replacement for cement, the compressive strength and density of blocks generally decreased with higher ...

  2. potentials of cement kiln dust in sub-grade improvement

    2013-03-01

    Mar 1, 2013 ... alternative uses of waste materials in different geotech- nical application including .... tained in bags and stored in air tight containers. The. CKD was ... Figure 5: Variation of plastic limit with cement kiln dust. Figure 6: Variation ...

  3. Improvement of poor subgrade soils using cement kiln dust

    Ahmed Mancy Mosa

    2017-12-01

    Full Text Available Construction of pavements layers on subgrade with excellent to good properties reduces the thickness of the layers and consequently reduces the initial and maintenance cost of highways and vice versa. However, construction of pavements on poor subgrade is unavoidable due to several constrains. Improvement of subgrade properties using traditional additives such as lime and Portland cement adds supplementary costs. Therefore, using by-products in this domain involves technical, economic, and environmental advantages. Cement kiln dust (CKD is generated in huge quantities as a by-product material in Portland cement plants. Therefore, it can be considered as an excellent alternative in this domain. In Iraq, Portland cement plants generate about 350000 tons of CKD annually which is available for free. Therefore, Iraq can be adopted as a case study. This paper covers using CKD to improve the properties of poor subgrade soils based on series of California Bearing Ration (CBR tests on sets of untreated samples and samples treated with different doses of CKD in combination with different curing periods to investigate their effects on soil properties. The results exhibited that adding 20% of CKD with curing for 14 days increases the CBR value from 3.4% for untreated soil to 48% for treated soil; it, also, decreases the swelling ratio. To determine the effects of using this dose under the mentioned curing period on the designed thicknesses of pavements layers, a case study was adopted. The case study results exhibited that treatment of the subgrade soil by 20% of CKD with curing for 14 days reduces the cost of the pavements by $25.875 per square meter.

  4. Feasibility of backfilling mines using cement kiln dust, fly ash, and cement blends

    Beltagui, Hoda; Sonebi, Mohammed; Maguire, K.; Taylor, Susan

    2018-01-01

    Cement kiln dust (CKD) is an industrial by-product of the cement manufacturing process, the composition of which can vary widely. Recent years of using alternative fuels have resulted in higher chloride and alkali contents within CKDs; as such, this limits the applications in which CKDs can be utilised. Using a CKD containing a high free lime content of 29.5%, it is shown that this CKD is capable of activating pulverized fuel ash (PFA) due to its high alkalinity, which can be utilised in low ...

  5. Mechanism and Modelling for Sorption of Toxic Ion on Cement Kiln Dust

    EI- Dakroury, A.; Sayed, M.S.; EL- Sherif, E.

    2009-01-01

    Cement manufacturing is a critically important industry in Egypt. These industrial by-product and waste materials must be managed responsibly to insure a clean and safe environment. Cement kiln dust (CKD) is a significant by-product material of the cement manufacturing process. Cement kiln dust is a waste residue composed chiefly of oxidized, anhydrous, micron - sized particles generated as a by product of the manufacture of Portland cement. The use of cement kiln dust as adsorbent in wastewater treatment has a great attention as cheap material and clay structure. This work will discuss the basic characteristics of CKD physical and chemical properties and regulatory requirements: The batch removal of Cr(VI) from aqueous solution using low cost adsorbents such as cement kiln dust under different experimental conditions. The influences of initial Cr (VI) ion concentration (20 to 300 mg1-1) and ph (1 to 4) were investigated in this study. Adsorption of Cr (VI) is highly ph-dependent and the results indicate that the optimum ph for the removal was found to be 1 for CKD. A comparison of kinetic models applied to the adsorption of Cr (VI) ions on the CKD was evaluated for the pseudo first order, the pseudo second-order, Elovich and intra particle diffusion kinetic models, respectively. The results showed that the pseudo second-order kinetic model was found to correlate the experimental data well

  6. Energy conservation and dust production in wet rotary cement kilns

    Sell, N J; Fischbach, F A

    1976-12-01

    Energy conservation is currently a major concern of the cement industry. A comparison of data supplied by the U.S. Federal Energy Administration with that gathered in an extensive private study incorporating 29 wet cement plants indicates that a significant reduction of the energy consumed can be accomplished by decreasing the amount of dust generated in the process. Energy saving of 8 percent through dust suppression appears possible by increasing the slurry moisture and by using hammermills rather than impactors as the crushing technique.

  7. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust.

    Moon, Deok Hyun; Grubb, Dennis G; Reilly, Trevor L

    2009-09-15

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration soil-cement slurries aged for 30 days enabled the identification of Se precipitates by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX). XRD and SEM-EDX analyses of the Se(IV)- and Se(VI)-soil-cement slurries revealed that the key selenium bearing phases for all three soil-cement slurries were calcium selenite hydrate (CaSeO(3).H(2)O) and selenate substituted ettringite (Ca(6)Al(2)(SeO(4))(3)(OH)(12).26H(2)O), respectively.

  8. Mechanical properties of Self-Consolidating Concrete incorporating Cement Kiln Dust

    El-Mohsen, Mostafa Abd; Anwar, Ahmed M.; Adam, Ihab A.

    2015-01-01

    Self-Consolidating Concrete (SCC) has been widely used in both practical and laboratory applications. Selection of its components and their ratios depends, mainly, on the target mechanical and physical properties recommended by the project consultant. Partial replacement of cement in SCC with cheap available industrial by-product could produce environmentally durable concrete with similar properties of normal concrete. In the current research, SCC was produced by blending Cement Kiln Dust (CK...

  9. Feasibility of backfilling mines using cement kiln dust, fly ash, and cement blends

    Beltagui H.

    2018-01-01

    Full Text Available Cement kiln dust (CKD is an industrial by-product of the cement manufacturing process, the composition of which can vary widely. Recent years of using alternative fuels have resulted in higher chloride and alkali contents within CKDs; as such, this limits the applications in which CKDs can be utilised. Using a CKD containing a high free lime content of 29.5%, it is shown that this CKD is capable of activating pulverized fuel ash (PFA due to its high alkalinity, which can be utilised in low strength un-reinforced applications. One potential application involves the backfill of mines, reducing the need for continuous maintenance of the mine. This study focuses on the compressive strength achieved by various blends of CKD, PFA, and cement. Samples were hand mixed and compacted in 100 mm x 50 mm diameter cylinders, and unconfined compressive strength measurements taken at 28 and 56 days. The hydration products were assessed through the use of x-ray diffraction and thermogravimetric analysis. Aiming to maximise the use of CKD at a water to binder (w/b ratio of 0.2, it was found that the maximum CKD content possible to achieve the required strength was 90% CKD blended with 10% cement.

  10. Lime kiln dust as a potential raw material in portland cement manufacturing

    Miller, M. Michael; Callaghan, Robert M.

    2004-01-01

    In the United States, the manufacture of portland cement involves burning in a rotary kiln a finely ground proportional mix of raw materials. The raw material mix provides the required chemical combination of calcium, silicon, aluminum, iron, and small amounts of other ingredients. The majority of calcium is supplied in the form of calcium carbonate usually from limestone. Other sources including waste materials or byproducts from other industries can be used to supply calcium (or lime, CaO), provided they have sufficiently high CaO content, have low magnesia content (less than 5 percent), and are competitive with limestone in terms of cost and adequacy of supply. In the United States, the lime industry produces large amounts of lime kiln dust (LKD), which is collected by dust control systems. This LKD may be a supplemental source of calcium for cement plants, if the lime and cement plants are located near enough to each other to make the arrangement economical.

  11. Mechanical properties of Self-Consolidating Concrete incorporating Cement Kiln Dust

    Mostafa Abd El-Mohsen

    2015-04-01

    Full Text Available Self-Consolidating Concrete (SCC has been widely used in both practical and laboratory applications. Selection of its components and their ratios depends, mainly, on the target mechanical and physical properties recommended by the project consultant. Partial replacement of cement in SCC with cheap available industrial by-product could produce environmentally durable concrete with similar properties of normal concrete. In the current research, SCC was produced by blending Cement Kiln Dust (CKD with cement in different ratios. Four mixes incorporating cement kiln dust with partial cement replacement of 10%, 20%, 30%, and 40% were produced and compared with a control mix of Normally Vibrated Concrete (NVC. Superplasticizer was used to increase the flow-ability of SCC mixes. The fresh and hardened mechanical properties of all mixes were determined and evaluated. Moreover, time-dependent behavior was investigated for all mixes in terms of drying shrinkage test. The shrinkage strain was measured for all specimens for a period of 120 days. Based on the experimental results, it was found that SCC mixture containing 20% cement replacement of CKD exhibited the highest mechanical strength compared to other SCC mixes and NVC mix as well. It was observed that the volumetric changes of specimens were directly proportional to the increase of the cement replacement ratio.

  12. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust

    Moon, Deok Hyun; Grubb, Dennis G.; Reilly, Trevor L.

    2009-01-01

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO 3 2- ) and selenate (SeO 4 2- ). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10 mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration 3 .H 2 O) and selenate substituted ettringite (Ca 6 Al 2 (SeO 4 ) 3 (OH) 12 .26H 2 O), respectively.

  13. New Medium for Isolation of Bacteria From Cement Kiln Dust with a Potential to Apply in Bio-Concrete

    Alshalif, A. F.; Irwan, J. M.; Othman, N.; Al-Gheethi, A.

    2018-04-01

    The present study aimed to introduce a new isolation medium named kiln dust medium (KDM) for recovering of bacteria from cement kiln dust with high pH (>pH 11) without the need for nutrients additives. The cement kiln dust samples were collected from five different areas of Cement Industries of Malaysia Berhad (CIMA). The bacterial isolates were recovered on KDM by direct plating technique. The chemical components for all collected samples were identified using X-ray fluorescence (XRF). The primary identification for the bacterial isolates indicated that these bacteria belongs to Bacillus spp. Based on the morphological characteristics. The growth curve of the bacterial strains was monitored using the optical density (OD) with 650 nm wavelength, which in role confirmed that all isolated bacteria had the ability to grow successfully in the proposed medium. The ability of the bacterial strains to grow at high pH reflects their potential in the bio-concrete applications (aerated and non-aerated concrete). These findings indicated that the cement kiln dust samples from Cement Industries represent the most appropriate source for bacteria used in the bioconcrete.

  14. Physicochemical characterization of cement kiln dust for potential reuse in acidic wastewater treatment

    Mackie, A.; Boilard, S.; Walsh, M.E.; Lake, C.B.

    2010-01-01

    Cement kiln dust (CKD) is a fine-grained material produced during the manufacture of cement. Current reuse options are limited and the bulk of CKD not reused in the cement manufacturing process is sent to landfills or stored on-site. Due to the calcium oxide (CaO) content of CKD, it has the potential to be used as a replacement for lime in treating acidic wastewaters such as acid rock drainage (ARD). This paper outlines the results of an examination of the physical and chemical properties of CKD samples collected from six cement plants. The CKD samples were analyzed for major oxides using X-ray diffraction (XRD), available lime, specific surface area, particle size, and morphology using scanning electron microscope (SEM) and compared with a commercial quicklime product. Conductivity, pH, and calcium concentrations of slaked CKD and quicklime solutions were used as indicators of reactivity of the CKD. Slaking of two of the CKD samples with the highest free lime contents (e.g., 34 and 37% free CaO) gave elevated pH values statistically comparable to those of the commercial quicklime sample that was characterized as having 87% available CaO. Acid neutralization trials indicate that even CKD samples with low free lime contents could be effective at neutralizing acidic wastewaters.

  15. Reuse of Cement Kiln Dust for backfilling and CO2 carbonation

    Lutyński Marcin

    2017-01-01

    Full Text Available The study aims to investigate possible alternative paths of reusing Cement Kiln Dust in mining technologies or as mineral sorbent for CO2 capture. Properties of CKD and bottom slag slurry were assessed and these were ia.: chemical composition, compressive strength and excess water content. Results show that CKD/bottom slag slurry mixed in the proportion of 25%/75% can be used as a backfill material if concentration of contaminants in the leaching tests is at the acceptable level. Second part of the study was devoted to the assessment of CKD as a sorbent in Calcium looping technologies or for mineral carbonation. TGA and DSC study shows that the rate of CO2 capture (carbonation is determined by the free CaO content. The highest carbonation rate was within the temperature range of 600-800°C.

  16. Influence Of Cement Kiln Dust As Partial Replacement On Some Properties Of Ordinary And White Portland Cement

    Salah Sharif

    2013-04-01

    Full Text Available Cement Kiln Dust (CKD is produced as a solid waste with large quantities during manufacturing of Portland cement clinker. The possibility of utilizing CKD as partial replacement for Ordinary Portland Cement (OPC and White Portland Cement (WPC produced in factories of the Iraqi cement state company has been examined in this study to fulfil the environmental and economical aims. Different percentages of CKD were blended with OPC and WPC mixes. The results show that the amount of water for normal consistency were increased with about 39 % and 31 % for OPC and WPC blended with 25 % CKD. The setting time (initial and final decreases with increasing percent of CKD added. Compressive strength decreases slightly with increasing CKD content up to 10 %. For 7- day curing time, it decreases 7 % and 9 % for OPC and WPC mixes, respectively. As percent of added CKD increases to more than 10 %, the compressive strength and other parameters where affected significantly. Overall results proved that OPC and WPC blended with up to 10 % CKD are admissible for passing relevant specification requirements.

  17. Improvement of geotechnical properties of sabkha soil utilizing cement kiln dust

    Abdullah A. Al-Homidy

    2017-08-01

    Full Text Available Improvement of properties of weak soils in terms of strength, durability and cost is the key from engineering point of view. The weak soils could be stabilized using mechanical and/or chemical methods. Agents added during chemical stabilization could improve the engineering properties of treated soils. Stabilizers utilized have to satisfy noticeable performance, durability, low price, and can be easily implemented. Since cement kiln dust (CKD is industrial by-product, it would be a noble task if this waste material could be utilized for stabilization of sabkha soil. This study investigates the feasibility of utilizing CKD for improving the properties of sabkha soil. Soil samples are prepared with 2% cement and 10%, 20% or 30% CKD and are tested to determine their unconfined compressive strength (UCS, soaked California bearing ratio (CBR and durability. Mechanism of stabilization is studied utilizing advanced techniques, such as the scanning electron microscope (SEM, energy dispersive X-ray analysis (EDX, backscattered electron image (BEI and X-ray diffraction analysis (XRD. It is noted that the sabkha soil mixed with 2% cement and 30% CKD could be used as a sub-base material in rigid pavements. The incorporation of CKD leads to technical and economic benefits.

  18. Phytoextraction of chloride from a cement kiln dust (CKD) contaminated landfill with Phragmites australis.

    McSorley, Kaitlin; Rutter, Allison; Cumming, Robert; Zeeb, Barbara A

    2016-05-01

    Cement kiln dust (CKD) is a globally produced by-product from cement manufacturing that is stockpiled or landfilled. Elevated concentrations of chloride pose toxic threats to plants and aquatic communities, as the anion is highly mobile in water and can leach into surrounding water sources. Re-vegetation and in situ phytoextraction of chloride from a CKD landfill in Bath, ON, Canada, was investigated with the resident invasive species Phragmites australis (haplotype M). Existing stands of P. australis were transplanted from the perimeter of the site into the highest areas of contamination (5.9×10(3)μg/g). Accumulation in the shoots of P. australis was quantified over one growing season by collecting samples from the site on a bi-weekly basis and analyzing for chloride. Concentrations decreased significantly from early May (24±2.2×10(3)μg/g) until mid-June (15±2.5×10(3)μg/g), and then remained stable from June to August. Shoot chloride accumulation was not significantly affected by water level fluctuations at the site, however elevated potassium concentrations in the soil may have contributed to uptake. Based on shoot chloride accumulation and total biomass, it was determined that phytoextraction from the CKD landfill can remove 65±4kg/km(2) of chloride per season. Based on this extraction rate, removal of chloride present in the highly contaminated top 10cm of soil can be achieved in 3-9years. This is the first study to apply phytotechnologies at a CKD landfill, and to successfully demonstrate in situ phytoextraction of chloride. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Mechanism for the stabilization/solidification of arsenic-contaminated soils with Portland cement and cement kiln dust.

    Yoon, In-Ho; Moon, Deok Hyun; Kim, Kyoung-Woong; Lee, Keun-Young; Lee, Ji-Hoon; Kim, Min Gyu

    2010-11-01

    In this study, the mechanism for the stabilization/solidification (S/S) of arsenic (As)-contaminated soils with Portland cement (PC), and cement kiln dust (CKD) using 1 N HCl extraction fluid, X-ray powder diffraction (XRPD), X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy was investigated. The degree of As immobilization after stabilization was assessed using a 1 N HCl extraction on the basis of the Korean Standard Test (KST). After 1 day of curing with 30 wt% PC and 7 days of curing with 50 wt% CKD, the concentration of As leached from the amended soils was less than the Korean countermeasure standard (3 mg L(-1)). The As concentrations in the leachate treated with PC and CKD were significantly decreased at pH > 3, indicating that pH had a prevailing influence on As mobility. XRPD results indicated that calcium arsenite (Ca-As-O) and sodium calcium arsenate hydrate (NaCaAsO(4).7.5H(2)O) were present in the PC- and CKD-treated slurries as the key phases responsible for As(III) and As(V) immobilization, respectively. The XANES spectroscopy confirmed that the As(III) and As(V) oxidation states of the PC and CKD slurry samples were consistent with the speciated forms in the crystals identified by XRPD. EXAFS spectroscopy showed As-Ca bonding in the As(III)-PC and As(III)-CKD slurries. The main mechanism for the immobilization of As-contaminated soils with PC and CKD was strongly associated with the bonding between As(III) or As(V) and Ca. Copyright 2010 Elsevier Ltd. All rights reserved.

  20. Physico-mechanical Properties of Electron Beam Irradiated Particle boards Based on Wood flour/ Polyethylene/Cement Kiln Dust Impregnated with Unsaturated Polyester

    Abdel-Rahman, H.A.; Khattab, M.M.; Ismail, M.R.

    2010-01-01

    Particle boards were fabricated by mixing wood flour (WF), low density polyethylene (LDPE) and cement kiln dust (CKD) under hot pressure; and then impregnated in unsaturated polyester resin. These impregnated particle boards were subjected to various doses of electron beam irradiation up to 50 kGy. The physico-mechanical properties were characterized in terms of flexural strength, impact strength, water absorption, thickness swelling, and the thermal stability. The results showed that the partial replacement of wood flour with cement kiln dust up to 20% by weight improved the values of flexural strength, and impact strength. However, the water absorption percentage and thickness swelling values decreased with increasing the CKD ratio up to 40%. Furthermore, the treatment with electron beam irradiation doses improved the physico-mechanical properties of the impregnated particle boards up to 50 kGy. The improved results were confirmed by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA)

  1. Removal of Heavy Metal Ions by Using Composite of Cement Kiln Dust/Ethylene Glycol co Acrylic Acid Prepared by y-Irradiation

    Sokker, H.H.; Abdel-Rahman, H.A.; Khattab, M.M.; Ismail, M.R.

    2010-01-01

    Various composites of cement kiln dust (CKD) and poly(ethylene glycol co acrylic acid) using y-irradiation was investigated. The samples were prepared using three percentages of cement kiln dust namely, 20, 50 and 75 by wt % and mixed with an equimolar ratio (1:1) of ethylene glycol and acrylic acid then irradiated at doses; 10,20 and 30 kGy of gamma-irradiation. The results showed that (CKD) and poly(ethylene glycol co acrylic acid) composites were formed only at 30 kGy. In addition, CKD alone has the lowest degree of removal of heavy metal ions compared with the prepared composites. A composite containing 75% cement kiln dust by weight percentage, showed the highest degree of removal of cobalt ions, whereas, a composite of 20% CKD showed the highest degree for cadmium ion removal. While the composite of 75% CKD showed a higher selectivity of cobalt ion than cadmium ion in their mixed solution.

  2. Bench-scale study of active mine water treatment using cement kiln dust (CKD) as a neutralization agent.

    Mackie, Allison L; Walsh, Margaret E

    2012-02-01

    The overall objective of this study was to investigate the potential impact on settled water quality of using cement kiln dust (CKD), a waste by-product, to replace quicklime in the active treatment of acidic mine water. Bench-scale experiments were conducted to evaluate the treatment performance of calcium hydroxide (Ca(OH)(2)) slurries generated using four different CKD samples compared to a control treatment with quicklime (CaO) in terms of reducing acidity and metals concentrations in acid mine drainage (AMD) samples taken from the effluent of a lead/zinc mine in Atlantic Canada. Results of the study showed that all of the CKD samples evaluated were capable of achieving greater than 97% removal of total zinc and iron. The amount of solid alkaline material required to achieve pH targets required for neutralization of the AMD was found to be higher for treatment with the CKD slurries compared to the quicklime slurry control experiments, and varied linearly with the free lime content of the CKD. The results of this study also showed that a potential benefit of treating mine water with CKD could be reduced settled sludge volumes generated in the active treatment process, and further research into the characteristics of the sludge generated from the use of CKD-generated calcium hydroxide slurries is recommended. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Assessment of cement kiln dust (CKD) for stabilization/solidification (S/S) of arsenic contaminated soils.

    Moon, Deok Hyun; Wazne, Mahmoud; Yoon, In-Ho; Grubb, Dennis G

    2008-11-30

    A stabilization/solidification (S/S) process for arsenic (As) contaminated soils was evaluated using cement kiln dust (CKD). Laboratory-prepared slurries, made of either kaolinite or montmorillonite, and field soils spiked with either As(3+) or As(5+) were prepared and treated with CKD ranging from 10 to 25 wt%. Sodium arsenite and sodium arsenate at 0.1 wt% were used to simulate arsenite (As(3+)) and arsenate (As(5+)) source contamination in soils, respectively. The effectiveness of treatment was evaluated at curing periods of 1- and 7-days based on the toxicity characteristic leaching procedure (TCLP). As-CKD and As-clay-CKD slurries were also spiked at 10 wt% to evaluate As immobilization mechanism using X-ray powder diffraction (XRPD) analyses. Overall, the TCLP results showed that only the As(5+) concentrations in kaolinite amended with 25 wt% CKD after 1 day of curing were less than the TCLP regulatory limit of 5mg/L. Moreover, at 7 days of curing, all As(3+) and As(5+) concentrations obtained from kaolinite soils were less than the TCLP criteria. However, none of the CKD-amended montmorillonite samples satisfied the TCLP-As criteria at 7 days. Only field soil samples amended with 20 wt% CKD complied with the TCLP criteria within 1 day of curing, where the source contamination was As(5+). XRPD and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) results showed that Ca-As-O and NaCaAsO(4).7.5H(2)O were the primary phases responsible for As(3+) and As(5+) immobilization in the soils, respectively.

  4. Assessment of cement kiln dust (CKD) for stabilization/solidification (S/S) of arsenic contaminated soils

    Moon, Deok Hyun; Wazne, Mahmoud; Yoon, In-Ho; Grubb, Dennis G.

    2008-01-01

    A stabilization/solidification (S/S) process for arsenic (As) contaminated soils was evaluated using cement kiln dust (CKD). Laboratory-prepared slurries, made of either kaolinite or montmorillonite, and field soils spiked with either As 3+ or As 5+ were prepared and treated with CKD ranging from 10 to 25 wt%. Sodium arsenite and sodium arsenate at 0.1 wt% were used to simulate arsenite (As 3+ ) and arsenate (As 5+ ) source contamination in soils, respectively. The effectiveness of treatment was evaluated at curing periods of 1- and 7-days based on the toxicity characteristic leaching procedure (TCLP). As-CKD and As-clay-CKD slurries were also spiked at 10 wt% to evaluate As immobilization mechanism using X-ray powder diffraction (XRPD) analyses. Overall, the TCLP results showed that only the As 5+ concentrations in kaolinite amended with 25 wt% CKD after 1 day of curing were less than the TCLP regulatory limit of 5 mg/L. Moreover, at 7 days of curing, all As 3+ and As 5+ concentrations obtained from kaolinite soils were less than the TCLP criteria. However, none of the CKD-amended montmorillonite samples satisfied the TCLP-As criteria at 7 days. Only field soil samples amended with 20 wt% CKD complied with the TCLP criteria within 1 day of curing, where the source contamination was As 5+ . XRPD and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) results showed that Ca-As-O and NaCaAsO 4 .7.5H 2 O were the primary phases responsible for As 3+ and As 5+ immobilization in the soils, respectively

  5. Investigation into the use of cement kiln dust in high density sludge (HDS) treatment of acid mine water.

    Mackie, Allison L; Walsh, Margaret E

    2015-11-15

    The purpose of this study was to investigate the potential to replace lime with cement kiln dust (CKD) in high density sludge (HDS) treatment of acid mine drainage (AMD). The bench-scale study used two water samples: AMD sampled from a lead-zinc mine with high concentrations of iron (Fe), zinc (Zn), and arsenic (As) (Fe/Zn-AMD) and a synthetic AMD solution (Syn-AMD) spiked with ferric sulfate (Fe2(SO4)3). Arsenic was found to be significantly reduced with CKD-HDS treatment of Fe/Zn-AMD compared to lime-HDS treatment, to concentrations below the stringent mine effluent discharge regulation of 0.10 mg As/L (i.e., 0.04 ± 0.02 mg/L). Both CKD- and lime-HDS treatment of the two AMD samples resulted in settled water Fe concentrations above the stringent discharge guideline of 0.3 mg Fe/L. CKD addition in the HDS process also resulted in high settled water turbidity, above typical discharge guidelines of 15 mg TSS/L. CKD-HDS treatment was found to result in significantly improved settled solids (i.e., sludge) quality compared to that generated in the lime-HDS process. HDS treatment with CKD resulted in 25-88% lower sludge volume indices, 2 to 9 times higher % wet solids, and 10 to 20 times higher % dry solids compared to lime addition. XRD and XPS testing indicated that CKD-HDS sludge consisted of mainly CaCO3 and SiO2 with Fe(3+) precipitates attached at particle surfaces. XRD and XPS testing of the lime-HDS generated sludge showed that it consisted of non-crystalline Fe oxides typical of sludge formed from precipitates with a high water concentration. Increased sedimentation rates were also found for CKD (1.3 cm/s) compared to lime (0.3 cm/s). The increased solids loading with CKD addition compared to lime addition in the HDS process was suggested to both promote surface complexation of metal precipitates with insoluble CKD particles and increase compression effects during Type IV sedimentation. These mechanisms collectively contributed to the reduced water content of

  6. Use of Cement Kiln Dust, Blast Furnace Slag and Marble Sludge in the Manufacture of Sustainable Artificial Aggregates by Means of Cold Bonding Pelletization.

    Colangelo, Francesco; Cioffi, Raffaele

    2013-07-25

    In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding pelletization process in artificial aggregate sustainable production.

  7. Use of Cement Kiln Dust, Blast Furnace Slag and Marble Sludge in the Manufacture of Sustainable Artificial Aggregates by Means of Cold Bonding Pelletization

    Raffaele Cioffi

    2013-07-01

    Full Text Available In this work, three different samples of solid industrial wastes cement kiln dust (CKD, granulated blast furnace slag and marble sludge were employed in a cold bonding pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding pelletization process in artificial aggregate sustainable production.

  8. Refuse derived fuels in Cement Kilns: Italian experience

    Del Borghi, M.; Strazza, C.; Del Borghi, A.

    2009-01-01

    This study investigates the results of a year (2006) of air emissions gathering in the various Italian cement plants, and, in particular, on 73 kilns subdivided by production class, kiln type and alternative fuels use for type and quantity. The emission parameters considered have been: total dust, SO 2 , NOx, CO, TOC, HCl, HF, metals, PAH and PCDD/F. The work has involved a comparison between the results of the average concentrations detected for the various pollutants, separately for the plants using only traditional fuels and using also alternative fuels. The obtained results show that the use of alternative fuels by the 22 kilns investigated has not any influence on the emission values of the pollutants examined; on the contrary, in certain cases these emissions result less than the limits legally allowed for the use of traditional fuels. A comparison between the results obtained from the Italian kilns and those published by Cembureau from 200 European kilns, confirms that the emission performances of cement kilns appear independent for the use of alternative fuels with the percentages usually employed. This study also highlights the benefits on the global environmental balance for the use of RDF as alternative fuel. [it

  9. 40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Options for incinerators, cement kilns... Technology (MACT) Standards § 270.235 Options for incinerators, cement kilns, lightweight aggregate kilns... incinerator, cement kiln, lightweight aggregate kiln, solid fuel boiler, liquid fuel boiler, or hydrochloric...

  10. Dust extraction from gas in cement kilns, using bag filters; Depoussierage des gaz de four cimentier par les filtres a manches

    Harmegnies, M. [CALCIA, 78 - Guerville (France). Direction Technique

    1996-12-31

    After a review of regulations concerning cement plant emissions, the two main cement production techniques (dry and semi-dry processes) are described and the electrostatic and bag filter de-dusting techniques are compared. Examples of pilot applications of these techniques in two French cement plants are presented and operating results (performances, transient procedures, costs) are discussed

  11. Case study: improvement of performance of cement industry rotary kilns by using a solid radiotracers

    Sebastian, C.; Maghella, G.; Mamani, E.

    2000-12-01

    In the present report, residence time distribution (RTD) of the cement blended raw meal has been determined by the use of 7,4x10 8 Bq (20 mCi) of La 40 as a dust radioactive tracer in the chemical form of La 2 O 3 . Five scintillation detector were installed alongside the kiln. Analysis and interpretation of response curves were made to draw conclusions about the improvement of the rotary kiln performance

  12. Environmental impact of incineration of calorific industrial waste: rotary kiln vs. cement kiln.

    Vermeulen, Isabel; Van Caneghem, Jo; Block, Chantal; Dewulf, Wim; Vandecasteele, Carlo

    2012-10-01

    Rotary kiln incinerators and cement kilns are two energy intensive processes, requiring high temperatures that can be obtained by the combustion of fossil fuel. In both processes, fossil fuel is often substituted by high or medium calorific waste to avoid resource depletion and to save costs. Two types of industrial calorific waste streams are considered: automotive shredder residue (ASR) and meat and bone meal (MBM). These waste streams are of current high interest: ASR must be diverted from landfill, while MBM can no longer be used for cattle feeding. The environmental impact of the incineration of these waste streams is assessed and compared for both a rotary kiln and a cement kiln. For this purpose, data from an extensive emission inventory is applied for assessing the environmental impact using two different modeling approaches: one focusing on the impact of the relevant flows to and from the process and its subsystems, the other describing the change of environmental impact in response to these physical flows. Both ways of assessing emphasize different aspects of the considered processes. Attention is paid to assumptions in the methodology that can influence the outcome and conclusions of the assessment. It is concluded that for the incineration of calorific wastes, rotary kilns are generally preferred. Nevertheless, cement kilns show opportunities in improving their environmental impact when substituting their currently used fuels by more clean calorific waste streams, if this improvement is not at the expense of the actual environmental impact. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    2010-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL... Waste Combustors Replacement Emissions Standards and Operating Limits for Incinerators, Cement Kilns... burning cement kilns? (a) Emission and hazardous waste feed limits for existing sources. You must not...

  14. Combustion of solid alternative fuels in the cement kiln burner

    Nørskov, Linda Kaare

    In the cement industry there is an increasing environmental and financial motivation for substituting conventional fossil fuels with alternative fuels, being biomass or waste derived fuels. However, the introduction of alternative fuels may influence emissions, cement product quality, process...... stability, and process efficiency. Alternative fuel substitution in the calciner unit has reached close to 100% at many cement plants and to further increase the use of alternative fuels rotary kiln substitution must be enhanced. At present, limited systematic knowledge of the alternative fuel combustion...... properties and the influence on the flame formation is available. In this project a scientific approach to increase the fundamental understanding of alternative fuel conversion in the rotary kiln burner is employed through literature studies, experimental combustion characterisation studies, combustion...

  15. Health hazards of cement dust

    Meo, Sultan A.

    2004-01-01

    ven in the 21st century, millions of people are working daily in a dusty environment. They are exposed to different types of health hazards such as fume, gases and dust, which are risk factors in developing occupational disease. Cement industry is involved in the development of structure of this advanced and modern world but generates dust during its production. Cement dust causes lung function impairment, chronic obstructive lung disease, restrictive lung disease, pneumoconiosis and carcinoma of the lungs, stomach and colon. Other studies have shown that cement dust may enter into the systemic circulation and thereby reach the essentially all the organs of body and affects the different tissues including heart, liver, spleen, bone, muscles and hairs and ultimately affecting their micro-structure and physiological performance. Most of the studies have been previously attempted to evaluate the effects of cement dust exposure on the basis of spirometry or radiology, or both. However, collective effort describing the general effects of cement dust on different organ and systems in humans or animals, or both has not been published. Therefore, the aim of this review is to gather the potential toxic effects of cement dust and to minimize the health risks in cement mill workers by providing them with information regarding the hazards of cement dust. (author)

  16. A Thermoelectric Waste-Heat-Recovery System for Portland Cement Rotary Kilns

    Luo, Qi; Li, Peng; Cai, Lanlan; Zhou, Pingwang; Tang, Di; Zhai, Pengcheng; Zhang, Qingjie

    2015-06-01

    Portland cement is produced by one of the most energy-intensive industrial processes. Energy consumption in the manufacture of Portland cement is approximately 110-120 kWh ton-1. The cement rotary kiln is the crucial equipment used for cement production. Approximately 10-15% of the energy consumed in production of the cement clinker is directly dissipated into the atmosphere through the external surface of the rotary kiln. Innovative technology for energy conservation is urgently needed by the cement industry. In this paper we propose a novel thermoelectric waste-heat-recovery system to reduce heat losses from cement rotary kilns. This system is configured as an array of thermoelectric generation units arranged longitudinally on a secondary shell coaxial with the rotary kiln. A mathematical model was developed for estimation of the performance of waste heat recovery. Discussions mainly focus on electricity generation and energy saving, taking a Φ4.8 × 72 m cement rotary kiln as an example. Results show that the Bi2Te3-PbTe hybrid thermoelectric waste-heat-recovery system can generate approximately 211 kW electrical power while saving 3283 kW energy. Compared with the kiln without the thermoelectric recovery system, the kiln with the system can recover more than 32.85% of the energy that used to be lost as waste heat through the kiln surface.

  17. Imaging of Flames in Cement Kilns To Study the Influence of Different Fuel Types

    Pedersen, Morten Nedergaard; Nielsen, Mads; Clausen, Sønnik

    2017-01-01

    The cement industry aims to use an increased amount of alternative fuels to reduce production costs and CO2 emissions. In this study three cement plants firing different kinds and percentages of alternative fuel were studied. A specially developed camera setup was used to monitor the flames...... in the three cement kilns and assess the effect of alternative fuels on the flame. It was found that cofiring with solid recovered fuel (SRF) would delay the ignition point by about 2 m and lower the intensity and temperature of the kiln flame compared to a fossil fuel flame. This is related to a larger...... particle size and moisture content of the alternative fuels, which lowers the conversion rate compared to fossil fuels. The consequences can be a lower kiln temperature and cement quality. The longer conversion time may also lead to the possibility of localized reducing conditions in the cement kiln, which...

  18. Effect of cement dust pollution on certain physical parameters of maize crop and soils

    Parthasarathy, S; Arunachalam, N; Natarajan, K; Oblisami, G; Rangaswami, G

    1975-04-01

    A study was undertaken in the fields near a cement factory where the cement dust is the prime pollutant to the field crops and soils. Cement dust deposit varied with the distance from the kiln and fourth and fifth leaves of maize had comparatively more dust than the first three leaves from the top. The cement dust deposited plants showed a suppression in most of the characters like leaf size, number and size of cobs and plant height when compared to plants in non-polluted fields. On comparison with the physical characters of the soils from the control field the soil from cement dust polluted field showed a decrease in water holding capacity and pore space while thermal conductivity and specific heat were more. Artificial mixtures of red and black soils with cement dust showed similar trend as those of the field sample, the black soil being affected more seriously than the red soil.

  19. Impact of kiln thermal energy demand and false air on cement kiln flue gas CO2 capture

    Arachchige, Udara S.P.R.; Kawan, Dinesh; Tokheim, Lars-Andre [Telemark University College, Porsgrunn (Norway); Melaaen, Morten C. [Telemark University College, Porsgrunn (Norway); (Tel-Tek, Porsgrunn (Norway)

    2013-07-01

    The present study is focused on the effect of the specific thermal energy demand and the false air factor on carbon capture applied to cement kiln exhaust gases. The carbon capture process model was developed and implemented in Aspen Plus. The model was developed for flue gases from a typical cement clinker manufacturing plant. The specific thermal energy demand as well as the false air factor of the kiln system were varied in order to determine the effect on CO2 capture plant performance, such as the solvent regeneration energy demand. In general, an increase in the mentioned kiln system factors increases the regeneration energy demand. The reboiler energy demand is calculated as 3270, 3428 and 3589 kJ/kg clinker for a specific thermal energy of 3000, 3400 and 3800 kJ/kg clinker, respectively. Setting the false air factor to 25, 50 or 70% gives a reboiler energy demand of 3428, 3476, 3568 kJ/kg clinker, respectively.

  20. Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

    Yufei Yang

    2013-01-01

    Full Text Available To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V and mainly existed as Mg3(AsO42, Ca3(AsO42, and Na2HAsO4.

  1. Increased Coal Replacement in a Cement Kiln Burner by Feeding a Mixture of Solid Hazardous Waste and Shredded Plastic Waste

    Ariyaratne, W. K. Hiromi; Melaaen, Morten Christian; Tokheim, Lars-André

    2013-01-01

    The present study aims to find the maximum possible replacement of coal by combined feeding of plastic waste and solid hazardous waste mixed with wood chips (SHW) in rotary kiln burners used in cement kiln systems. The coal replacement should be achieved without negative impacts on product quality, emissions or overall operation of the process. A full-scale experiment was carried out in the rotary kiln burner of a cement kiln by varying SHW and plastic waste feeding rates. Experimental result...

  2. SO2 Release as a Consequence of Alternative Fuel Combustion in Cement Rotary Kiln Inlets

    Cortada Mut, Maria del Mar; Nørskov, Linda Kaare; Glarborg, Peter

    2015-01-01

    The combustion of alternative fuels in direct contact with the bed material of the rotary kiln may cause local reducing conditions and, subsequently, decomposition of sulfates from cement raw materials, increasing the SO2 concentration in the gas phase. The decomposition of sulfates increases...... the sulfur circulation and may be problematic because high sulfur circulation can cause sticky material buildup, affecting the process operation of the cement kiln system. The SO2 release from cement raw materials during combustion of pine wood and tire rubber has been studied experimentally in a high...

  3. Sustainability of cement kiln co-processing of wastes in India: a pilot study.

    Baidya, Rahul; Ghosh, Sadhan Kumar; Parlikar, Ulhas V

    2017-07-01

    Co-processing in cement kiln achieves effective utilization of the material and energy value present in the wastes, thereby conserving the natural resources by reducing the use of virgin material. In India, a number of multifolded initiatives have been taken that take into account the potential and volume of waste generation. This paper studies the factors which might influence the sustainability of co-processing of waste in cement kilns as a business model, considering the issues and challenges in the supply chain framework in India in view of the four canonical pillars of sustainability. A pilot study on co-processing was carried out in one of the cement plant in India to evaluate the environmental performance, economical performance, operational performance and social performance. The findings will help India and other developing countries to introduce effective supply chain management for co-processing while addressing the issues and challenges during co-processing of different waste streams in the cement kilns.

  4. Dynamic measurement of mercury adsorption and oxidation on activated carbon in simulated cement kiln flue gas

    Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian

    2012-01-01

    of the sulfite converter is short and typically within 2min. Dynamic mercury adsorption and oxidation tests on commercial activated carbons Darco Hg and HOK standard were performed at 150°C using simulated cement kiln gas and a fixed bed reactor system. It is shown that the converter and analyzer system...... are still under development and are investigated in this work. A commercial red brass converter was tested at 180°C and it was found that the red brass chips work in nitrogen atmosphere only, but do not work properly under simulated cement kiln flue gas conditions. Test of the red brass converter using only...... elemental mercury shows that when HCl is present with either SO2 or NOx the mercury measurement after the converter is unstable and lower than the elemental mercury inlet level. The conclusion is that red brass chips cannot fully reduce oxidized mercury to elemental mercury when simulated cement kiln gas...

  5. Case study: improvement of performance of cement industry rotary kilns by using a solid radiotracers; Caso estudio: Mejora de la eficiencia en hornos rotativos de la industria del cemento utilizando radioisotopos

    Sebastian, C; Maghella, G; Mamani, E [Direccion de Aplicaciones. Instituto Peruano de Energia Nuclear, Lima (Peru)

    2000-12-01

    In the present report, residence time distribution (RTD) of the cement blended raw meal has been determined by the use of 7,4x10{sup 8} Bq (20 mCi) of La 40 as a dust radioactive tracer in the chemical form of La{sub 2}O{sub 3}. Five scintillation detector were installed alongside the kiln. Analysis and interpretation of response curves were made to draw conclusions about the improvement of the rotary kiln performance.

  6. Fiscal 1999 basic survey report for promotion of joint implementation. Survey of diffusion of fluidized bed cement kilns in Vietnam; 1999 nendo Vietnam koku ni okeru ryudosho cement kiln fukyu chosa hokokusho

    NONE

    2000-03-01

    Possibility is assessed of energy saving and CO2 reduction through replacing shaft kilns with fluidized bed kilns at four cement plants in Vietnam. The effort will be associated with the clean development mechanism (CDM) ultimately. The fluidized bed kiln is one of the state-of-the-art technologies developed to meet social, economic, and technical demands involving global environments, enhancement of energy efficiency, effective use of resources, improvement in cost performance, increasingly diversified needs for cement, etc. Use of the technology will lead to an extensive reduction in greenhouse gas emissions, solution of the problem of dust flying from calcinating facilities, production of clinkers high in stability and quality, utilization of inexpensive fuels such as low-grade coal, and production cost reduced thanks to the new equipment occupying less installation space. The conclusion of the study is that the energy to be consumed by the four plants will decrease by 6101-9551 tons/year in terms of oil and that energy saving rate will be 37-44%. The decrease in fuel and electricity for calcinating furnaces in turn decreases CO2 emissions, with the amount of reduction estimated at 24,393-38,794 tons/year in terms of CO2 and the rate of reduction estimated at 36-44%. As for payout in case environmental special yen credit is granted, it will realize in the 10-12th year, which means such financing will achieve a sufficient investment effect. Effect is also tentatively calculated in case of fluidized bed kilns diffused across the country. (NEDO)

  7. Combustion of large solid fuels in cement rotary kilns

    Nielsen, Anders Rooma

    (MBM), waste wood, sewage sludge, paper and plastics. The alternative fuel share of the total energy varies significantly from region to region, but the general trend is towards increased alternative fuel utilization. Solid alternative fuels typically have physical and chemical properties that differ...... from traditional solid fossil fuels. This creates a need for new combustion equipment or modification of existing kiln systems, because alternative fuels may influence process stability and product quality. Process stability is mainly influenced by exposing the raw material bed in the rotary kiln...... oxidation is a slow process which may greatly reduce the amounts of solid fuels to be utilized in the material inlet end of rotary kilns due to the limited residence time. Several parameters control the rate of char oxidation: a) bulk oxygen concentration, b) mass transfer rate of oxygen to char particles...

  8. Perspectives and limits for cement kilns as a destination for RDF

    Genon, G.; Brizio, E.

    2008-01-01

    RDF, the high calorific value fraction of MSW obtained by conventional separation systems, can be employed in technological plants (mainly cement kilns) in order to obtain a useful energy recovery. It is interesting and important to evaluate this possibility within the general framework of waste-to-energy solutions. The solution must be assessed on the basis of different aspects, namely: technological features and clinker characteristics; local atmospheric pollution; the effects of RDF used in cement kilns on the generation of greenhouse gases; the economics of conventional solid fuels substitution and planning perspectives, from the point of view of the destination of RDF and optimal cement kiln policy. The different experiences of this issue throughout Europe are reviewed, and some applications within Italy are also been considered. The main findings of the study are that the use of RDF in cement kilns instead of coal or coke offers environmental benefits in terms of greenhouse gases, while the formation of conventional gaseous pollutants is not a critical aspect. Indeed, the generation of nitrogen oxides can probably be lower because of lower flame temperatures or lower air excess. The presence of chlorinated micro-pollutants is not influenced by the presence of RDF in fuel, whereas depending on the quality of the RDF, some problems could arise compared to the substituted fuel as far as heavy metals are concerned, chiefly the more volatile ones

  9. Perspectives and limits for cement kilns as a destination for RDF.

    Genon, G; Brizio, E

    2008-11-01

    RDF, the high calorific value fraction of MSW obtained by conventional separation systems, can be employed in technological plants (mainly cement kilns) in order to obtain a useful energy recovery. It is interesting and important to evaluate this possibility within the general framework of waste-to-energy solutions. The solution must be assessed on the basis of different aspects, namely: technological features and clinker characteristics; local atmospheric pollution; the effects of RDF used in cement kilns on the generation of greenhouse gases; the economics of conventional solid fuels substitution and planning perspectives, from the point of view of the destination of RDF and optimal cement kiln policy. The different experiences of this issue throughout Europe are reviewed, and some applications within Italy are also been considered. The main findings of the study are that the use of RDF in cement kilns instead of coal or coke offers environmental benefits in terms of greenhouse gases, while the formation of conventional gaseous pollutants is not a critical aspect. Indeed, the generation of nitrogen oxides can probably be lower because of lower flame temperatures or lower air excess. The presence of chlorinated micro-pollutants is not influenced by the presence of RDF in fuel, whereas depending on the quality of the RDF, some problems could arise compared to the substituted fuel as far as heavy metals are concerned, chiefly the more volatile ones.

  10. Cement factory kilns. Clinker baking workshops; Fours de cimenterie. Ateliers de cuisson du clinker

    Bastier, R. [Direction Centrale Technologie (France); Bocan, A.; Gerbert, B.; Regnault, A.

    2000-07-01

    Clinker baking is the intermediate of the three main steps of the cement fabrication process. The aim of the baking workshop is the thermal transformation of the crude material into a semi-product (clinker). The problem of clinker baking is to find the optimum process taking into account: the investment and operation costs,the diversity of raw materials and fuels, the socio-economical constraints, the performances required, the environmental constraints and the increase of production capacity. This paper gives a presentation of the different types of clinker baking workshops: 1 - Rotative kiln and baking workshop; 2 - Different types of baking workshops: general considerations, humid way process (long kiln - WL), half-dry way process (short kiln - DG-N), dry-way process (short kiln - DS-X), comparison of standard energy consumptions and production ratios; 3 - Pre-calcination (DS-X-SF and DS-X-PC kilns): general considerations, industrial realizations, operation of pre-calcination, characteristics, advantages and drawbacks, standard operation data; 4 - Dimensioning of dry-way kilns: theoretical and empirical methods. (J.S.)

  11. Feasibility of disposing waste glyphosate neutralization liquor with cement rotary kiln

    Bai, Y.; Bao, Y.B.; Cai, X.L.; Chen, C.H. [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China); Ye, X.C., E-mail: yexuchu@njtech.edu.cn [College of Materials Science and Engineering, Nanjing Tech University, Nanjing 210009 (China); State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (China)

    2014-08-15

    Highlights: • The waste neutralization liquor was injected directly into the kiln system. • No obvious effect on the quality of cement clinker. • The disposing method was a zero-discharge process. • The waste liquor can be used as an alternative fuel to reduce the coal consumption. - Abstract: The waste neutralization liquor generated during the glyphosate production using glycine-dimethylphosphit process is a severe pollution problem due to its high salinity and organic components. The cement rotary kiln was proposed as a zero discharge strategy of disposal. In this work, the waste liquor was calcinated and the mineralogical phases of residue were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The mineralogical phases and the strength of cement clinker were characterized to evaluate the influence to the products. The burnability of cement raw meal added with waste liquor and the calorific value of waste liquor were tested to evaluate the influence to the thermal state of the kiln system. The results showed that after the addition of this liquor, the differences of the main phases and the strength of cement clinker were negligible, the burnability of raw meal was improved; and the calorific value of this liquor was 6140 J/g, which made it could be considered as an alternative fuel during the actual production.

  12. Feasibility of disposing waste glyphosate neutralization liquor with cement rotary kiln

    Bai, Y.; Bao, Y.B.; Cai, X.L.; Chen, C.H.; Ye, X.C.

    2014-01-01

    Highlights: • The waste neutralization liquor was injected directly into the kiln system. • No obvious effect on the quality of cement clinker. • The disposing method was a zero-discharge process. • The waste liquor can be used as an alternative fuel to reduce the coal consumption. - Abstract: The waste neutralization liquor generated during the glyphosate production using glycine-dimethylphosphit process is a severe pollution problem due to its high salinity and organic components. The cement rotary kiln was proposed as a zero discharge strategy of disposal. In this work, the waste liquor was calcinated and the mineralogical phases of residue were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The mineralogical phases and the strength of cement clinker were characterized to evaluate the influence to the products. The burnability of cement raw meal added with waste liquor and the calorific value of waste liquor were tested to evaluate the influence to the thermal state of the kiln system. The results showed that after the addition of this liquor, the differences of the main phases and the strength of cement clinker were negligible, the burnability of raw meal was improved; and the calorific value of this liquor was 6140 J/g, which made it could be considered as an alternative fuel during the actual production

  13. Numerical Study on Heat Transfer to an Arc Absorber Designed for a Waste Heat Recovery System around a Cement Kiln

    Hosseini, Seyed Mojtaba Mir; Rezaniakolaei, Alireza; Rosendahl, Lasse Aistrup

    2018-01-01

    A numerical study on combined free convection, forced convection, and radiation heat transfers from an industrial isothermal rotating cylinder (cement kiln) is carried out in this work. The investigation is done by the study of two-dimensional (2D) incompressible turbulent flow around the kiln un...

  14. Development of electro fused aggregates for use in refractories for the burning zone of cement kilns

    Ferreira, Luis Leonardo Horne Curimbaba

    2006-01-01

    Electro fused aggregates are largely used in refractory production due to the better performance reached when they are employed. In this work electro fused aggregates were designed for application in refractories for the burning zone of cement kilns. Initially reaction evaluation was conducted aiming the identification of the most prone refractory systems when single refractory phases react with Portland cement phases at high temperatures. In the next step, raw materials of the best refractory systems were electro fused to generate different aggregate compositions. The electro fused aggregates properties were evaluated and the classified ones were used to produce refractory bricks for the burning zone of cement kilns. General characteristics of these bricks were measured and compared with a standard magnesia-spinel refractory. Aggregates of the system Mg O - TiO 2 - Ca O, more specifically aggregates belonged to the compatibility triangle Mg O - Mg 2 TiO 4 - CaTiO 3 , showed suitable characteristics for development of refractories for the burning zone cement kilns. (author)

  15. Sulfur Release during Alternative fuels Combustion in Cement Rotary Kilns

    Cortada Mut, Maria del Mar

    fuel with the bed material, heating up of a particle, 5 iv devolatilization, char combustion, the reactions between CaSO 4 and the different reducing agents, and the oxidation of the volatiles gases in the free board. The main reducing agents are CO, CH 4 and H 2 , which are introduced under the bed...... are of high importance for SO 2 release because it is shown that introducing the same total amount of gas, the highest reducing agent concentration fo r a short period released a higher total SO 2 amount compared to the lowest concentration during a long period. A mathematical reaction based model...... but the effect of sulfur content in the bed cannot be predicted. Further development regarding particle motion according to the rotational speed may be needed. Furthermore, a model for predicting the tendency of build-ups for a kiln system is developed based on the prediction of SO 3 and Cl concentrations...

  16. Basic survey project for joint implementation. Feasibility study for the diffusion of fluidized bed cement kiln system in China; 1998 nendo kyodo jisshi nado suishin kiso chosa. Chugoku ni okeru ryudosho cement kirun fukyu chosa

    NONE

    1999-03-01

    Discussions were given on conversion of shaft kilns mainly used at Tianjin Cement and Huaxin Cement to the fluidized bed cement kiln of the most advanced type. Possibility of energy conservation in China, that is reduction of carbon dioxide emission, was evaluated. This system has been developed by the Center for Coal Utilization, Japan. The system is characterized by reduction of greenhouse effect gas emission, elimination of the problem of dust scattering from sintering facilities, stabilized production of high-quality clinker, capability of using low-grade coal and anthracite, and reduction of cement production cost. As a result of the discussions, the reduction rate of greenhouse effect gases was found about 17 to 33%. The cost effect may be calculated as 2 to 5 thousand yen per ton of CO2 reduction amount assuming the system life of 20 years. If this process has been diffused into China, the quantity of CO2 to be reduced will reach about four million tons annually assuming a diffusion rate of 10%. This project shows as high profitability as about 20% at IRR, and the system is more advantageous economically than the shaft kiln. (NEDO)

  17. Improvement of energy efficiency in glass-melting furnaces, cement kilns and baking ovens

    Carvalho, M.D.G. [Technical University of Lisbon (Portugal). Instituto Superior Tecnico; Nogueira, M. [IrRADIARE, R and D in Engineering andrsholm Environment, Oeiras (Portugal)

    1997-08-01

    This paper is aimed at presenting the utilisation of dedicated modelling tools for the optimisation of a variety of thermal equipment for high-, medium-, and low-temperature heat transfer process. A combination of modelling with advanced extensive on-line measurements is proposed as an approach for the development of optimisation procedures able to be used in equipment design and operation. The industrially oriented utilisation of modelling is discussed considering the state-of-the-art and the application of existing codes capable of computing the three-dimensional characteristics of the aerodynamics, mixing, combustion (single- or multi-phase), pollutants formation and heat transfer of industrial combustion equipment. The present paper describes modelling tools for the optimisation of a glass-melting furnace, a ceramic kiln, a cement kiln and a baking oven. Significant reduction of energy consumption and low-cost abatement were achieved for these four industrial situations. (author)

  18. Selenium recovery from kiln powder of cement manufacturing by chemical leaching and bioreduction.

    Soda, S; Hasegawa, A; Kuroda, M; Hanada, A; Yamashita, M; Ike, M

    2015-01-01

    A novel process by using chemical leaching followed by bacterial reductive precipitation was proposed for selenium recovery from kiln powder as a byproduct of cement manufacturing. The kiln powder at a slurry concentration of 10 w/v% with 0.25 M Na2CO3 at 28°C produced wastewater containing about 30 mg-Se/L selenium. The wastewater was diluted four-fold and adjusted to pH 8.0 as preconditioning for bioreduction. A bacterial strain Pseudomonas stutzeri NT-I, capable of reducing selenate and selenite into insoluble elemental selenium, could recover about 90% selenium from the preconditioned wastewater containing selenium of 5 mg-Se/L when supplemented with lactate or glycerol. The selenium concentrations in the treated wastewater were low around the regulated effluent concentration of 0.1 mg-Se/L in Japan.

  19. Glass-making furnaces, cement kilns and baking ovens

    1989-01-01

    Possible areas for future strategic R and D within the European Community in the cement, glass and bake industries are identified based upon the current scenario of R and D in process industries and following views of main industries and research experts. Priority topics for R and D should include advanced flow modelling, the implementation of control strategies and expert systems and the development of on-line sensors. Fundamental research in some areas, such as advanced diagnostic techniques and sensor systems and modelling of two-phase and pollutant formation, is considered of primary importance.

  20. Degradation of Alumina and Magnesia Chrome refractory bricks in Portland cement kiln – Corrected version*

    Ben Addi K.

    2014-05-01

    Full Text Available In cement plants, the refractory products are particularly confronted to partially liquid oxide phases at temperature ranging between 900°C and 1700°C. All constituents of these products have to resist not only to thermal constraints, but also to the thermochemical solicitations which result from contact material/coating. In order to study the phenomenon of degradation of refractory bricks in cement kilns and to identify the causes of their degradation, we proceed to the examination of industrial cases in cement kiln. Many chemical tests of the degraded refractory bricks have been done and the results acquired were compared to the ones not used. The analysis of the results is doing using different techniques (Loss of ignition, X-ray Fluorescence, X-ray Diffraction. The results show that the degradation of the used bricks in the clinkering and cooling zone is due to the infiltration of aggressive elements such us sulphur, alkali (Na2O, K2O .... The chemical interaction between the Portland clinker phases and refractory material has also an importance on the stability of the coating and consequently on the life of the refractories.

  1. Internet and Fuzzy Based Control System for Rotary Kiln in Cement Manufacturing Plant

    Hanane Zermane

    2017-01-01

    Full Text Available This paper develops an Internet-based fuzzy control system for an industrial process plant to ensure the remote and fuzzy control in cement factories in Algeria. The remote process consists of control, diagnosing alarms occurs, maintaining and synchronizing different regulation loops. Fuzzy control of the kiln ensures that the system be operational at all times, with minimal downtime. Internet technology ensures remote control. The system reduces downtimes and can guided by operators in the main control room or via Internet.

  2. Effect of flue gas recirculation during oxy-fuel combustion in a rotary cement kiln

    Granados, David A.; Chejne, Farid; Mejía, Juan M.; Gómez, Carlos A.; Berrío, Ariel; Jurado, William J.

    2014-01-01

    The effect of Flue Gas Recirculation (FGR) during Oxy-Fuel Combustion in a Rotary Cement Kiln was analyzed by using a CFD model applied to coal combustion process. The CFD model is based on 3D-balance equations for mass, species, energy and momentum. Turbulence and radiation model coupled to a chemical kinetic mechanism for pyrolysis processes, gas–solid and gas–gas reactions was included to predicts species and flame temperature distribution, as well as convective and radiation energy fluxes. The model was used to study coal combustion with air and with oxygen for FGR between 30 and 85% as controller parameter for temperature in the process. Flame length effect and heat transfer by convection and radiation to the clinkering process for several recirculation ratios was studied. Theoretical studies predicted a located increase of energy flux and a reduction in flame length with respect to the traditional system which is based on air combustion. The impact of FGR on the oxy-fuel combustion process and different energy scenarios in cement kilns to increase energy efficiency and clinker production were studied and evaluated. Simulation results were in close agreement with experimental data, where the maximum deviation was 7%

  3. Life cycle assessment of the use of alternative fuels in cement kilns: A case study.

    Georgiopoulou, Martha; Lyberatos, Gerasimos

    2018-06-15

    The benefits of using alternative fuels (AFs) in the cement industry include reduction of the use of non-renewable fossil fuels and lower emissions of greenhouse gases, since fossil fuels are replaced with materials that would otherwise be degraded or incinerated with corresponding emissions and final residues. Furthermore, the use of alternative fuels maximizes the recovery of energy. Seven different scenaria were developed for the production of 1 ton of clinker in a rotary cement kiln. Each of these scenaria includes the use of alternative fuels such as RDF (Refuse derived fuel), TDF (Tire derived fuel) and BS (Biological sludge) or a mixture of them, in partial replacement of conventional fuels such as coal and pet coke. The purpose of this study is to evaluate the environmental impacts of the use of alternative fuels in relation to conventional fuels in the kiln operation. The Life Cycle Assessment (LCA) methodology is used to quantify the potential environmental impacts in each scenario. The interpretation of the results provides the conclusion that the most environmentally friendly prospect is the scenario based on RDF while the less preferable scenario is the scenario based on BS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Personal exposure to inhalable cement dust among construction workers

    Peters, Susan; Kromhout, Hans; Thomassen, Yngvar; Fechter-Rink, Edeltraud

    2009-01-01

    A case study was carried out in 2006-2007 to assess the actual cement dust exposure among construction workers involved in a full-scale construction project and as a comparison among workers involved in various stages of cement and concrete production. Full-shift personal exposure measurements were performed for several job types. Inhalable dust and cement dust (based on analysis of elemental calcium) concentrations were determined. Inhalable dust exposures at the construction site ranged from 0.05 to 34 mg/m3, with a mean concentration of 1.0 mg/m3. For inhalable cement dust mean exposure was 0.3 mg/m3 (range 0.02-17 mg/m3). Reinforcement and pouring workers had the lowest average concentrations. Inhalable dust levels in the ready-mix and pre-cast concrete plants were, on average, below 0.5 mg/m3 for inhalable dust and below 0.2 mg/m3 for inhalable cement dust. Highest dust concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM=55 mg/m3; inhalable cement dust GM=33 mg/m3) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages of cement during reinforcement work and pouring.

  5. Review of technologies for mercury removal from flue gas from cement production processes

    Zheng, Yuanjing; Jensen, Anker Degn; Windelin, Christian

    2012-01-01

    sources of mercury in the cement kiln flue gas. Cement plants are quite different from power plants and waste incinerators regarding the flue gas composition, temperature, residence time, and material circulation. Cement kiln systems have some inherent ability to retain mercury in the solid materials due...... to the adsorption of mercury on the solids in the cold zone. However, recirculation of the kiln dust to the kiln will cause release of the captured mercury. The mercury chemistry in cement kiln systems is complicated and knowledge obtained from power plants and incinerators cannot be directly applied in cement...

  6. A SYSTEM AND A METHOD FOR PREDICTION OF NOx EMISSION AND/OR FREE LIME CONCENTRATION IN A CEMENT KILN

    2008-01-01

    The invention relates to a method (and corresponding soft sensor) for determining one or more cement kiln process parameters, the method comprising the steps of collecting at least one process measurement representing at least one process parameter and collecting at least one item of image data r...

  7. 40 CFR 63.1204 - What are the standards for hazardous waste burning cement kilns that are effective until...

    2010-07-01

    ... Principal Organic Hazardous Constituents (POHCs) in the waste feed that you specify under paragraph (c)(3... in the hazardous waste feed, considering the results of hazardous waste analyses or other data and... waste burning cement kilns that are effective until compliance with the standards under § 63.1220? 63...

  8. Report of year 2000 version on feasibility study. Feasibility study on the diffusion of fluidized bed cement kiln system in Socialist Republic of Viet Nam

    NONE

    2000-03-01

    Evaluations were given on the possibility of saving energies and reducing CO2 emission by renewing the shaft kilns operated in four factories in Viet Nam into fluidized bed kilns. The feasibility study is intended to be linked to the clean development mechanism (CDM) in the future. The fluidized bed kiln is a most advanced technology developed to deal with social, economic and technological demands such as global environment preservation, energy conservation, effective utilization of resources, enhancement of economic performance, and diversification of cement needs. The technology is capable of largely reducing greenhouse effect gases, eliminating the problem of dust scattering from sintering facilities, producing stabilized and high-quality clinker, making possible of using inexpensive fuels including low-order coal, using less installation space, and reducing the production cost. The amount of energy reduction in all of the four factories is calculated 8,101 to 9,551 toe/year at an energy saving effect rate of 37 to 44%. CO2 emission is reduced as a result of reduction in fuel for sintering furnaces and in electric power consumption. The reduction amount would be 24,393 to 38,794 tons/year (converted into CO2), and the reduction effect rate would be 36 to 44%. The investment effect looks sufficient as payout of 10 to 12 years if the environment special Yen loan is used. Trial calculation was also performed for the nation-wide proliferation effect. (NEDO)

  9. Incorporation of cement bypass flue dust in fly ash and blast furnace slag-based geopolymer

    Mohamed E. Sultan

    2018-06-01

    Full Text Available This work utilizes cement kiln dust in fly ash and blast furnace slag-based geopolymer. Geopolymer cement was produced using different compositions of ground, granulated blast furnace slag with fly ash and cement bypass flue dust. Crystalline sodium metasilicate pentahydrate was used as an activator at 10, 15 and 20% (by weight of the geopolymer source materials. The geopolymer is formed in the solid state like ordinary Portland cement. The mechanical and chemical properties of the geopolymeric materials were examined. Measuring of mechanical properties by compressive strength of the hardened geopolymer pastes at different curing ages; microstructure was evaluated by X-ray diffraction (XRD and scanning electron microscope (SEM; thermal properties were estimated by thermogravimetry analysis (TGA and derivative thermogravimetric analysis (DTG. The results indicate that the compressive strength of the geopolymer pastes is increased with higher Na2SiO3.5H2O content. The geopolymeric properties were enhanced by higher pH, which helps in the dissolution of geopolymer source materials during geopolymerization. SEM showed that mixes containing 15 and 20% sodium metasilicate had more compact and dense structures. On the other hand, GGBFS mix (G-20 exhibits more hydration and geopolymeric products during TGA/DTG compared with other mixes which contain FA with/without GGBFS. Keywords: Cement bypass flue dust, Geopolymer, Ground granulated blast furnace, Fly ash

  10. Utilization of alternative fuels and materials in cement kiln towards emissions of benzene, toluene, ethyl-benzene and xylenes (BTEX

    Muliane Ulfi

    2018-01-01

    Full Text Available Co-processing in cement industry has benefits for energy conservation and waste recycling. Nevertheless, emissions of benzene, toluene, ethyl-benzene, and xylenes (BTEX tend to increase compared to a non co-processing kiln. A study was conducted in kiln feeding solid AFR (similar to municipal solid waste, MSW having production capacity 4600-ton clinker/day (max. 5000 ton/day and kiln feeding biomass having production capacity 7800-ton clinker/day (max. 8000 ton/day. The concentration of VOCs emissions tends to be higher at the raw mill on rather than the raw mill off. At the raw mill on, concentration of total volatile organic carbon (VOCs emission from cement kiln stack feeding Solid AFR 1, biomass, Solid AFR 2, and mixture of Solid AFR and biomass is 16.18 mg/Nm3, 16.15 mg/Nm3, 9.02 mg/Nm3, and 14.11 mg/Nm3 respectively. The utilization of biomass resulted in the lower fraction of benzene and the higher fraction of xylenes in the total VOCs emission. Operating conditions such as thermal substitution rate, preheater temperature, and kiln speed are also likely to affect BTEX emissions.

  11. Coal acid mine drainage treatment using cement kiln dust

    Edgar Alberto Martínez

    2014-01-01

    Full Text Available Los sulfuros están presentes en distintas rocas. Durante las actividades mineras y el proceso de remoción de sulfuros se pueden producir Drenajes Ácidos de Minería (DAM, con iones de sulfato (SO4-2. Los DAMs son fuente de polución en las actividades mineras y en Colombia su descarga en los cuerpos de agua debe cumplir las regulaciones nacionales (pH entre 5 y 9. Polvo de horno cementero (CKD, con carbonato de calcio principalmente, de una planta de Cementos Argos S.A. fue usado para neutralizar un DAM generado en la biodesulfurización de carbón. Los DAMs neutralizados tuvieron pHs entre 7,72 y 8,05 y la eliminación de sulfatos entre 67% a 70%. El precipitado se secó y analizó para determinar su composición química y mineralógica. Se encontró humedad entre 69% y 81%; yeso con un 50% de pureza aproximadamente y carbonato de calcio. Esta composición lo hace adecuado para uso en la producción de cemento.

  12. Personal exposure to inhalable cement dust among construction workers.

    Peters, Susan; Thomassen, Yngvar; Fechter-Rink, Edeltraud; Kromhout, Hans

    2009-01-01

    Objective- A case study was carried out to assess cement dust exposure and its determinants among construction workers and for comparison among workers in cement and concrete production.Methods- Full-shift personal exposure measurements were performed and samples were analysed for inhalable dust and its cement content. Exposure variability was modelled with linear mixed models.Results- Inhalable dust concentrations at the construction site ranged from 0.05 to 34 mg/m(3), with a mean of 1.0 mg/m(3). Average concentration for inhalable cement dust was 0.3 mg/m(3) (GM; range 0.02-17 mg/m(3)). Levels in the ready-mix and pre-cast concrete plants were on average 0.5 mg/m(3) (GM) for inhalable dust and 0.2 mg/m(3) (GM) for inhalable cement dust. Highest concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM = 55 mg/m(3); inhalable cement dust GM = 33 mg/m(3)) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages during reinforcement work and pouring. Most likely other sources were contributing to dust concentrations, particularly at the construction site. Within job groups, temporal variability in exposure concentrations generally outweighed differences in average concentrations between workers. 'Using a broom', 'outdoor wind speed' and 'presence of rain' were overall the most influential factors affecting inhalable (cement) dust exposure.Conclusion- Job type appeared to be the main predictor of exposure to inhalable (cement) dust at the construction site. Inhalable dust concentrations in cement production plants, especially during cleaning tasks, are usually considerably higher than at the construction site.

  13. Ways to achieve optimum utilization of waste gas heat in cement kiln plants with cyclone preheaters

    Steinbiss, E

    1986-02-01

    Kiln exit gases and the exhaust gases from clinker coolers often cannot be fully utilized in drying plants. In such cases a part of the heat content of the gases should be utilized for water heating. In addition, it is possible to utilize the waste gas heat in conventional steam boilers, with which, depending on design, it is possible to generate electricity at a rate of between 10-30 kWh/t (net output). A new and promising method of utilization of waste gas heat is provided by precalcining systems with bypass, in which up to 100% of the kiln exit gases can be economically bypassed and be utilized in a steam boiler, without requiring any cooling. A development project, already started, gives information on the operational behaviour of such a plant and on the maximum energy recoverable. Alternatively, the bypass gases may, after partial cooling with air or preheater exit gas, be dedusted and then utilized in a grinding/drying plant. Furthermore, they can be used in the cement grinding process for the drying of wet granulated blastfurnace slag or other materials. For this it is not necessary to dedust the bypass gases.

  14. The effect of sintering time on recycled magnesia brick from kiln of the cement plant

    Aji, B. B.; Rosalina, D.; Azhar; Amin, M.

    2018-01-01

    This research aim was to investigate the effect of sintering time on reuse waste of magnesia brick from the rotary kiln of the cement plant. Reuse of the magnesia brick was carried out by mixed the kaolin as the binder. Spent refractory was used as aggregate with the composition of 85% spent refractory and 15% kaolin clay, respectively. The reuse brick then was molded with the size of 5x5x5 cm using hydraulic press under a load of 10 tons in order to forms green body. Green body then dried and sintered at 1200 °C with time variation of 2 hours, 4 hours, 6 hours, 8 hours and 10 hours, respectively. Thus, for comparison reuse brick was tested to its apparent porosity, the bulk density, and Cold Crushing Strength (CCS). The effect of kaolin addition as binder was also discussed.

  15. Migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln.

    Huang, Yuyan; Li, Haoxin; Jiang, Zhengwu; Yang, Xiaojie; Chen, Qing

    2018-05-07

    The aim of this work was to investigate the migration and transformation of sulfur in the municipal sewage sludge during disposal in cement kiln, and better understand the emission of the sulfur related pollutants in this process. In consideration of the temperature conditions in the practical operation, municipal sewage sludge was pre-dried at 105 °C, and then dried at 210, 260 and 310 °C, co-combusted with cement raw mill at 800, 900 and 1000 °C, and 1350, 1400 and 1450 °C respectively in the laboratory. X-ray photoelectron spectroscopy (XPS) was used to determine the S2p spectral lines of the municipal sewage sludge treated in the different process. Besides, The Thermal Analysis-Thermogravimetry (DTA-TG), Back Scattered Electron (BSE) and Energy Dispersive Spectrometer (EDS) were also employed to explore the mechanism of sulfur subsistence at 1450 °C. The results indicate that sulfide, thiophene, sulfone and sulfate are mainly sulfur compound in the municipal sewage sludge dried at 105 °C. Sulfoxide, a new sulfur compound, appears after it is further dried at 210 °C. The relative contents of sulfide and thiophene are continuously declined as the drying temperature increases due to their evaporation, decomposition and transformation in this process. The transformation of sulfide and thiophene makes the relative contents of sulfoxide and sulfate accordingly increased. However, the relative content of sulfone experiences an elevating-lowering process while the dry temperature elevated from 210 to 310 °C. This case is related to its evaporation and decomposition, as well as its production for the transformation of sulfide and thiophene. In the co-combustion process, sulfide, thiophene and sulfone are entirely vanished for their evaporation, decomposition and transformation. Sulfone is still contained at 800 °C, but when the temperature unceasingly rises, it is completely decomposed or evaporated and sulfate is the only sulfur compound. The

  16. Personal exposure to inhalable cement dust among construction workers.

    Peters, S.M.; Thomassen, Y.; Fechter-Rink, E.; Kromhout, H.

    2009-01-01

    Objective- A case study was carried out to assess cement dust exposure and its determinants among construction workers and for comparison among workers in cement and concrete production.Methods- Full-shift personal exposure measurements were performed and samples were analysed for inhalable dust and

  17. Theoretical and experimental studies on combustion of alternative fuels in cement kilns

    Axelsen, Ernst Petter

    2002-01-01

    In this thesis, the utilization of alternative fuels for NOx reduction by means of reburning and advanced reburning is considered. Laboratory experiments, full-scale experiments and computational fluid dynamic (CFD) simulations are the basis of the thesis. The goal of the work was to characterize alternative fuels used in cement kilns, with focus on the processes taking place in the precalciner of the cement kiln. To facilitate testing under controlled process conditions, a lab-scale circulating fluidized bed combustion (CFBC) reactor was designed and constructed. A co prehensive study on the fluidization regime in CFBC reactors and precalciners was required to ensure and verify that the operational regime in the CFBC reactor was similar to the regime in a precalciner. Different alternative fuels, such as refuse derived fuel, animal meal and solid hazardous waste, were tested in the CFBC reactor, which proved well suited for characterization of alternative fuels and investigations of NOx reduction, even though the operation of a CFBC reactor is quite complex and gives a certain variation in stability. Experiments with and without circulating mass in the CFBC reactor demonstrated the importance of executing the laboratory combustion experiments in an environment similar to that in the full-scale process, i.e. in the precalciner. Animal meal is believed to follow the reduction route of selective non-catalytic r duction or advanced reburning and to have a special capability of reducing NOx during increased NOx concentrations at the reactor inlet. The increased CO emissions during advanced reburning and reburning with animal meal are most likely to be due to the competition for the OH radical during oxidation of CO and of NH 3 . Furthermore, it was shown, for all fuels, that an increased concentration of NOx at the reactor inlet increases the ratio of NOx at the exit and NOx supplied. Full-scale experiments were executed at Norcem's kiln 6 in Brevik, using solid

  18. Theoretical and experimental studies on combustion of alternative fuels in cement kilns

    Axelsen, Ernst Petter

    2002-07-01

    In this thesis, the utilization of alternative fuels for NOx reduction by means of reburning and advanced reburning is considered. Laboratory experiments, full-scale experiments and computational fluid dynamic (CFD) simulations are the basis of the thesis. The goal of the work was to characterize alternative fuels used in cement kilns, with focus on the processes taking place in the precalciner of the cement kiln. To facilitate testing under controlled process conditions, a lab-scale circulating fluidized bed combustion (CFBC) reactor was designed and constructed. A co prehensive study on the fluidization regime in CFBC reactors and precalciners was required to ensure and verify that the operational regime in the CFBC reactor was similar to the regime in a precalciner. Different alternative fuels, such as refuse derived fuel, animal meal and solid hazardous waste, were tested in the CFBC reactor, which proved well suited for characterization of alternative fuels and investigations of NOx reduction, even though the operation of a CFBC reactor is quite complex and gives a certain variation in stability. Experiments with and without circulating mass in the CFBC reactor demonstrated the importance of executing the laboratory combustion experiments in an environment similar to that in the full-scale process, i.e. in the precalciner. Animal meal is believed to follow the reduction route of selective non-catalytic r duction or advanced reburning and to have a special capability of reducing NOx during increased NOx concentrations at the reactor inlet. The increased CO emissions during advanced reburning and reburning with animal meal are most likely to be due to the competition for the OH radical during oxidation of CO and of NH{sub 3}. Furthermore, it was shown, for all fuels, that an increased concentration of NOx at the reactor inlet increases the ratio of NOx at the exit and NOx supplied. Full-scale experiments were executed at Norcem's kiln 6 in Brevik, using solid

  19. Theoretical and experimental studies on combustion of alternative fuels in cement kilns

    Axelsen, Ernst Petter

    2002-07-01

    In this thesis, the utilization of alternative fuels for NOx reduction by means of reburning and advanced reburning is considered. Laboratory experiments, full-scale experiments and computational fluid dynamic (CFD) simulations are the basis of the thesis. The goal of the work was to characterize alternative fuels used in cement kilns, with focus on the processes taking place in the precalciner of the cement kiln. To facilitate testing under controlled process conditions, a lab-scale circulating fluidized bed combustion (CFBC) reactor was designed and constructed. A co prehensive study on the fluidization regime in CFBC reactors and precalciners was required to ensure and verify that the operational regime in the CFBC reactor was similar to the regime in a precalciner. Different alternative fuels, such as refuse derived fuel, animal meal and solid hazardous waste, were tested in the CFBC reactor, which proved well suited for characterization of alternative fuels and investigations of NOx reduction, even though the operation of a CFBC reactor is quite complex and gives a certain variation in stability. Experiments with and without circulating mass in the CFBC reactor demonstrated the importance of executing the laboratory combustion experiments in an environment similar to that in the full-scale process, i.e. in the precalciner. Animal meal is believed to follow the reduction route of selective non-catalytic r duction or advanced reburning and to have a special capability of reducing NOx during increased NOx concentrations at the reactor inlet. The increased CO emissions during advanced reburning and reburning with animal meal are most likely to be due to the competition for the OH radical during oxidation of CO and of NH{sub 3}. Furthermore, it was shown, for all fuels, that an increased concentration of NOx at the reactor inlet increases the ratio of NOx at the exit and NOx supplied. Full-scale experiments were executed at Norcem's kiln 6 in Brevik, using

  20. the effect of cement dust exposure on haematological and liver

    Daniel Owu

    LIVER FUNCTION PARAMETERS OF CEMENT FACTORY WORKERS IN. SOKOTO ... to cement dust. (mean years of exposure = 9.6± 1.5 years) and 46 matched unexposed controls. ... was assessed by measuring serum liver function tests. .... of cement, may increase the risk of autoimmune disease. ... Mosby's Manual of.

  1. Corneal permeability for cement dust: prognosis for occupational safety

    Kalmykov, R. V.; Popova, D. V.; Kamenskikh, T. G.; Genina, E. A.; Tuchin, V. V.; Bashkatov, A. N.

    2018-02-01

    The high dust content in air of a working zone causes prevalence of pathologies of the anterior segment of the eye of workers of cement production. Therefore, studying of features of cement dust impact on structure of a cornea and development of ways of eye protection from this influence is relevant. In this work experimental studies were carried out with twenty eyes of ten rabbits. OCTtomography was used to monitor the light attenuation coefficient of the cornea in vitro during the permeability of cement dust and/or keratoprotector (Systein Ultra). The permeability coefficients of the cornea for water, cement dust and keratoprotector were measured. A computer model allowing one to analyze the diffusion of these substances in the eye cornea was developed. It was shown that 1) the cement dust falling on the eye cornea caused pronounced dehydration of the tissue (thickness decreasing) and led to the increase of the attenuation coefficient, which could affect the deterioration of the eyesight of workers in the conditions of cement production; 2) the application of the keratoprotector to the eye cornea when exposed by cement dust, slowed significantly the dehydration process and did not cause the increase of the attenuation coefficient that characterized the stabilization of visual functions. At this, the keratoprotector itself did not cause dehydration and led to the decrease of the attenuation coefficient, which could allow it to be used for a long time in the order to protect the organ of vision from the negative effects of cement dust.

  2. Peach leaf responses to soil and cement dust pollution.

    Maletsika, Persefoni A; Nanos, George D; Stavroulakis, George G

    2015-10-01

    Dust pollution can negatively affect plant productivity in hot, dry and with high irradiance areas during summer. Soil or cement dust were applied on peach trees growing in a Mediterranean area with the above climatic characteristics. Soil and cement dust accumulation onto the leaves decreased the photosynthetically active radiation (PAR) available to the leaves without causing any shade effect. Soil and mainly cement dust deposition onto the leaves decreased stomatal conductance, photosynthetic and transpiration rates, and water use efficiency due possibly to stomatal blockage and other leaf cellular effects. In early autumn, rain events removed soil dust and leaf functions partly recovered, while cement dust created a crust partially remaining onto the leaves and causing more permanent stress. Leaf characteristics were differentially affected by the two dusts studied due to their different hydraulic properties. Leaf total chlorophyll decreased and total phenol content increased with dust accumulation late in the summer compared to control leaves due to intense oxidative stress. The two dusts did not cause serious metal imbalances to the leaves, except of lower leaf K content.

  3. Impact of cement dust pollution on respiratory systems of Lafarge ...

    In this investigation, the impact of cement dust pollution on respiratory systems of Lafarge cement workers was evaluated. A total of 120 respondents; 60 from the factory workers and 60 (controls) from Ifo, a nearby village 22 km NE of the factory were interviewed in 2014 using a modified respiratory symptom score ...

  4. Effects of Co-Processing Sewage Sludge in the Cement Kiln on PAHs, Heavy Metals Emissions and the Surrounding Environment.

    Lv, Dong; Zhu, Tianle; Liu, Runwei; Li, Xinghua; Zhao, Yuan; Sun, Ye; Wang, Hongmei; Zhang, Fan; Zhao, Qinglin

    2018-04-08

    To understand the effects of co-processing sewage sludge in the cement kiln on non-criterion pollutants emissions and its surrounding environment, the flue gas from a cement kiln stack, ambient air and soil from the background/downwind sites were collected in the cement plant. Polycyclic aromatic hydrocarbons (PAHs) and heavy metals of the samples were analyzed. The results show that PAHs in flue gas mainly exist in the gas phase and the low molecular weight PAHs are the predominant congener. The co-processing sewage sludge results in the increase in PAHs and heavy metals emissions, especially high molecular weight PAHs and low-volatile heavy metals such as Cd and Pb in the particle phase, while it does not change their compositions and distribution patterns significantly. The concentrations and their distributions of the PAHs and heavy metals between the emissions and ambient air have a positive correlation and the co-processing sewage sludge results in the increase of PAHs and heavy metals concentrations in the ambient air. The PAHs concentration level and their distribution in soil are proportional to those in the particle phase of flue gas, and the co-processing sewage sludge can accelerate the accumulation of the PAHs and heavy metals in the surrounding soil, especially high/middle molecular weight PAHs and low-volatile heavy metals.

  5. Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

    Auday A Mehatlaf

    2017-01-01

    Cement Klin Dust (CKD) was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40) had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28) d...

  6. Study on the alternative mitigation of cement dust spread by capturing the dust with fogging method

    Purwanta, Jaka; Marnoto, Tjukup; Setyono, Prabang; Handono Ramelan, Ari

    2017-12-01

    The existence of a cement plant impact the lives of people around the factory site. For example the air quality, which is polluted by dust. Cement plant has made various efforts to mitigate the generated dust, but there are still alot of dust fly inground either from the cement factory chimneys or transportation. The purpose of this study was to conduct a review of alternative mitigation of the spread of dust around the cement plant. This study uses research methods such as collecting secondary data which includes data of rain density, the average rains duration, wind speed and direction as well as data of dust intensity quality around PT. Semen Gresik (Persero) Tbk.Tuban plant. A soft Wind rose file is used To determine the wind direction propensity models. The impact on the spread of dust into the environment is determined using secondary data monitoring air quality. Results of the study is that the mitigation of dust around the cement plant is influenced by natural factors, such as the tendency of wind direction, rain fall and rainy days, and the rate of dust emission from the chimney. The alternative means proposed is an environmental friendly fogging dust catcher.

  7. Potential to use waste tires as supplemental fuel in pulp and paper mill boilers, cement kilns and in road pavement

    Barlaz, M.A.; Eleazer, W.E. II (North Carolina State Univ., Raleigh, NC (United States). Dept. of Civil Engineering); Whittle, D.J.

    1993-12-01

    The objective of this paper is to evaluate the recycling potential of waste tires as an energy source and for use in road pavement. North Carolina, U.S.A., is used as a case study. Scrap tires may be burned for supplemental fuel in pulp and paper mill boilers and cement kilns. Five pulp and paper mill boilers in North Carolina could consume over 90% of the 6 million tires generated annually in the state. Cement kilns located within 400 km of North Carolina population centers could consume about 6.6 million tires annually. Based on the quantity of pavement laid in North Carolina, non-proprietary and proprietary versions of asphalt rubber concrete have the potential to consume 1.8 and 7.2 million tires, respectively. Rubber modified asphalt concrete has the potential to consume up to 16.5 million tires. However, technological and economic limitations suggest that large scale implementation is unlikely for the short term. Environmental considerations pertaining to each alternative are discussed. (author)

  8. Improvement of cement plant dust emission by bag filter system

    Wahyu Purnomo, Chandra; Budhijanto, Wiratni; Alfisyah, Muziibu; Triyono

    2018-03-01

    The limestone quarry in PT Indocement Tunggal Prakarsa (ITP) in Cirebon is considered as a complex quarry in terms of chemical composition and material hardness. From the beginning of the plant operation up to the end of 2015, the dust removal was rely on electrostatic precipitator (EP) system. Whenever limestone from specific quarry zones were incorporated into Raw Mill (RM) feed or there was an upset condition, the dust emission increased significantly. Beside higher demand of electricity, an EP system requires lower gas inlet temperature in order to remove the dust effectively which requires larger cooling water in the previous gas conditioning tower to cool down gas from 400 °C to about 100 °C. By considering the drawbacks, the EP system was replaced by a bag filter (BF) system. The BF allows higher temperature of gas inlet and it has higher dust removal efficiency. In this study, the efficiency of the two different dust removal systems is compared. The effect of process variables i.e. RM feed, kiln feed, inlet temperature and pressure, and small size particle fraction to the dust emission are studied by multivariate linier regression analysis. It is observed that the BF system can reduce significantly the dust emission from 30 to 6 mg/m3 and in the same time reducing CO2 emission by 0.24 ton/year from the electricity consumption saving.

  9. Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

    Auday A Mehatlaf

    2017-12-01

    Full Text Available Cement Klin Dust (CKD was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40 had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28 day. In addition, mechanical properties included the coefficient of thermal conductivity and compressive strength had also observed with different age (3,7, and 28 for all prepared specimens. From the obtained the experimental results and their discussion, it was clear that the addition (20% of CKD had the good results in cement mortars.  

  10. Solidification of Waste Steel Foudry Dust with Portland Cement

    Škvára, F.; Kaštánek, František; Pavelková, I.; Šolcová, Olga; Maléterová, Ywetta; Schneider, Petr

    B89, č. 1 (2001), s. 67-81 ISSN 0304-3894 R&D Projects: GA ČR GA104/99/0440 Institutional research plan: CEZ:AV0Z4072921; CEZ:MSM 223100002 Keywords : solidification, * foundry dust * cement Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.497, year: 2001

  11. Dose response effect of cement dust on respiratory muscles competence in cement mill workers.

    Meo, Sultan A; Azeem, Muhammad A; Qureshi, Aijaz A; Ghori, G Moinudin; Al-Drees, Abdul Majeed; Feisal Subhan, Mirza Muhammad

    2006-12-01

    Electromyography (EMG) of respiratory muscles is a reliable method of assessing the ventilatory muscle function, but still its use has not been fully utilized to determine the occupational and environmental hazards on respiratory muscles. Therefore, EMG of intercostal muscles was performed to determine the dose response effect of cement dust on respiratory muscles competence. Matched cross-sectional study of EMG in 50 non-smoking cement mill workers with an age range of 20 - 60 years, who worked without the benefit of cement dust control ventilation or respiratory protective devices. EMG was performed by using surface electrodes and chart recorder. Significant reduction was observed in number of peaks (p competence and stratification of results shows a dose-effect of years of exposure in cement mill.

  12. Utilization coke dust as fuel in the cement industry

    Nawaz, S.

    2006-01-01

    Utilization of coke dust available from coal carbonization plants, as a fuel in the cement industry has been undertaken and discussed in this research paper. The parameters studied include physical and chemical evaluation of the coke dust and its economic feasibility/ suitability as fuel for the cement plants. Detailed studies have been carried out on the above referred parameters. In addition a comparative study has been done to access its suitability in comparison to other fuels especially imported coal. It has been found that the coke dust contained about 66% fixed carbon, 29% ash, 4% volatile matter, 1% moisture and 0.48% sulphur. It gross calorific value was found to be 5292 Kcal/kg. The detailed analysis of coke dust ash was also performed to determine as to how its constituents will compare with the cement constituents. Keeping in view the experimental results/ data generated on the coke dust, it has been concluded that it can be quite a good substitute for imported coal. In doing so a substantial financial saving can be achieved which ranges 40-45%. (author)

  13. Utilizing TEMPO surface estimates to determine changes in emissions, community exposure and environmental impacts from cement kilns across North America using alternative fuels

    Pegg, M. J.; Gibson, M. D.; Asamany, E.

    2015-12-01

    A major problem faced by all North American (NA) Governments is managing solid waste from residential and non-residential sources. One way to mitigate the need to expand landfill sites across NA is waste diversion for use as alternative fuel in industries such as cement manufacture. Currently, waste plastic, tires, waste shingles and other high carbon content waste destined for landfill are being explored, or currently used, as an alternative supplemental fuels for use in cement kilns across NA. While this is an attractive, environmentally sustainable solution, significant knowledge gaps remain in our fundamental understanding of whether these alternative fuels may lead to increased air pollution emissions from cement kilns across NA. The long-term objective of using TEMPO is to advance fundamental understanding of uncharacterized air pollution emissions and to assess the actual or potential environmental and health impacts of these emissions from cement kilns across NA. TEMPO measurements will be made in concert with in-situ observations augmented by air dispersion, land-use regression and receptor modelling. This application of TEMPO follows on from current research on a series of bench scale and pilot studies for Lafarge Canada Inc., that investigated the change in combustion emissions from various mixtures of coal (C), petroleum coke (PC) and non-recyclable alternative fuels. From our work we demonstrated that using an alternative fuel mixture in a cement kiln has potential to reduce emissions of CO2 by 34%; reduce NOx by 80%, and reduce fuel SO2 emissions by 98%. We also provided evidence that there would be a significant reduction in the formation of secondary ground-level ozone (O3) and secondary PM2.5 in downwind stack plumes if alternative waste derived fuels are used. The application of air dispersion, source apportionment, land use regression; together with remote sensing offers a powerful set of tools with the potential to improve air pollution

  14. Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.

    Grosso, Mario; Dellavedova, Stefano; Rigamonti, Lucia; Scotti, Sergio

    2016-01-01

    The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Fiscal 2000 feasibility research on environmentally-friendly coal utilization system. Feasibility research project (Clinkering technology for fluidized bed cement kiln - China); 2000 nendo kankyo chowagata sekitan riyo system kanosei chosa hokokusho. Jisshi kanosei chosa jigyo (ryudosho cement kiln shosei gijutsu Chugoku)

    NONE

    2001-03-01

    Studies are conducted about the feasibility of the above-named technology in China, its energy conservation and environmental protection effects, and so forth. To be expected upon conversion of shaft kilns in China to fluidized bed kilns using this technology are energy conservation of approximately 30%; resultant reduction in greenhouse effect gas emissions, in the scattering of coarse particulates, and in NOx and SOx emissions, these in combination contributing to reduction in environmental pollution; stable production of high-quality clinker; preference to inexpensive fuels and the effective utilization of resources; reduction in the cement manufacturing cost; and so forth. On-site surveys were conducted at existing shaft kiln plants, and studies were made about conversion to fluidized bed cement kilns with a 1,000 tons/day capability. The conclusion was that the period of return on invested capital would be 3.94-8.98 years, dependent upon the degree of facilities renovation, showing the presence of high possibilities of a successful return on invested capital. It was estimated that the shaft kilns would bring about a yearly reduction of 840 tons of coarse particulates, 105 tons of SO{sub 2}, and 68,281 tons of CO2. (NEDO)

  16. Characteristics of ammonia emission during thermal drying of lime sludge for co-combustion in cement kilns.

    Liu, Wei; Xu, Jingcheng; Liu, Jia; Cao, Haihua; Huang, Xiang-Feng; Li, Guangming

    2015-01-01

    Thermal drying was used to reduce sludge moisture content before co-combustion in cement kilns. The characteristics of ammonia (NH3) emission during thermal drying of lime sludge (LS) were investigated in a laboratory-scale tubular dry furnace under different temperature and time conditions. As the temperature increased, the NH3 concentration increased in the temperature range 100-130°C, decreased in the temperature range 130-220°C and increased rapidly at >220°C. Emission of NH3 also increased as the lime dosage increased and stabilized at lime dosages>5%. In the first 60 min of drying experiments, 55% of the NH3 was released. NH3 accounted for about 67-72% of the change in total nitrogen caused by the release of nitrogen-containing volatile compounds (VCs) from the sludge. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the main forms of nitrogen in sludge were amides and amines. The addition of lime (CaO) could cause conversion of N-H, N-O or C-N containing compounds to NH3 during the drying process.

  17. The emission of particulate matters and heavy metals from cement kilns – case study: co-incineration of tires in Serbia

    Dušan Todorović

    2010-09-01

    Full Text Available Co-incineration of wastes started more than 20 years ago. In the last 10 years, the use of alternative fuels in the cement industry is continuously increasing. The use of solid wastes in cement kilns is one of the best technologies for a complete and safe destruction of these wastes, due to the fact that there is a simultaneous benefit of destroying wastes and getting the energy. However, particulate matters (PM and gaseous chemicals emitted from a source into the environment could be directly transmitted to humans through air inhalation. Therefore, for accurate health risk estimation, the emission of pollutants must be determined. In this work, the analysis of the emission of different pollutants when replacing partially the fuel type used in a cement kiln is done. PM, PM10, heavy metals and inorganic pollutants are analyzed. The methods used for sampling and analysis are the standard methods suggested by the EU regulations for stack analysis. Experimental results have shown the encouraging results: in particular clinker characteristics were unmodified, and stack emissions (NOx, SO2 and CO mainly were in the case of tires, slightly incremented but remaining almost always below the law imposed limits, and in some cases were even decreased.

  18. Air pollution hazards in brick kilns

    Aslam, M; Srivastava, R S; Minocha, A K; Gupta, R G [Central Building Research Institute, Roorkee (India)

    1994-02-01

    Three types of brick kiln - Bull's trench kiln of movable chimney type, Bull's trench kiln of fixed chimney type, and high draught kiln of normal capacity (25,000-30,000 bricks/day) fed manually with slack coal and other local fuels - were investigated for stack emissions. Dust and hydrocarbons were identified as chief pollutants. Particle size analysis of dust emitted from movable chimney kiln and its impact on ambient air quality were also studied. Based on these studies, recommendations have been drawn on their comparative pollution hazard and need for optimization of operational parameters to improve their thermal performance and reduce pollution emission. 15 refs., 4 tabs.

  19. The Fogging Method with Variable of Nozle Diameter as the Mitigation Alternative for Spreading the Dust of Cement

    Purwanta, J.; Marnoto, T.; Setyono, P.; Ramelan, A. H.

    2018-03-01

    The cement plant impacts on the lives of people around the factory site, one of them on the air quality, especially dust. Cement plant has made various efforts to mitigate dust generated, but the reality on the ground is still a lot of dust flying around either of the cement factory chimneys and transportation. The purpose of this study was to find the optimum condition of nozle diameter from the cement dust catcher, for mitigation the dust spread to around the cement plant. This study uses research methods such as collecting secondary data which includes data intensity rainfall, the average long rains, wind speed and direction as well as data quality monitoring dust around PT. Semen Gresik (Persero) Tbk. Tuban plant. To determine the wind direction propensity models, use a soft Windrose file. To determine the impact on the spread of dust into the environment using secondary data monitoring air quality. Results of the study is that the mitigation of dust around the cement plant is influenced by natural factors, namely the tendency of wind direction, rainfall and rainy days, and the rate of dust emission from the chimney. I try for operate the cement dust catcher with variable of nozle diameter. Finally, I find the optimum condition of nozle diameter for cement dust catcher is 1.40 mm, with line equation is y = 149.09.e 1.6237.x and error 5%. In that condition, nozle can make the fog with a good quality and it can catch the cement dust well.

  20. Effect of cement kiln dust and gamma irradiation on the ultrasonic parameters of HMO borate glasses

    Abd elfadeel, G. [Physics Department, Faculty of Science, Al-Azhar University, Assiut 71524 (Egypt); Saddeek, Yasser B., E-mail: ysaddeek@gmail.com [Physics Department, Faculty of Science, Al-Azhar University, Assiut 71524 (Egypt); Mohamed, Gehan Y. [Experimental Nuclear Physics Department, Nuclear Research Center, Atomic Energy Authority, Post Office No. 13759, Cairo (Egypt); Mostafa, A.M.A. [Physics Department, Faculty of Science, Al-Azhar University, Assiut 71524 (Egypt); Shokry Hassan, H. [Advanced Technology and New Materials Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, Alexandria 21934 (Egypt)

    2017-03-01

    Glass samples with the chemical formula x CKD—(100 − x) (5Na{sub 2}O–65 B{sub 2}O{sub 3}–9 Bi{sub 2}O{sub 3}–21PbO), (0 ⩽ x ⩽ 32 mol%) were prepared. The density and the ultrasonic estimations of the investigated glasses were analyzed at room temperature before and after the impact of two dosages of gamma irradiation to study the effect of both CKD and gamma radiation. It was found that the density, and the ultrasonic parameters are sensitive to the variety of the content of CKD and the effect of γ-radiation. Replacement of oxides with higher atomic weights such as Bi{sub 2}O{sub 3} and PbO by CKD decreases the density. Analysis of the behavior of the ultrasonic parameters demonstrates that creation of CaO{sub 6} and SiO{sub 4} on one hand and an alternate transformation between BO{sub 4} and BO{sub 3} structural units, on the other hand, affect the increase of the ultrasonic velocities and the elastic moduli. Moreover, the density and the ultrasonic parameters decrease somewhat with the increase of the doses of γ-irradiation. The variations of the previous physical parameters can be referred to the creation of radiation imperfections, which occupied the voids inside the glass structure.

  1. Effect of cement kiln dust and gamma irradiation on the ultrasonic parameters of HMO borate glasses

    Abd elfadeel, G.; Saddeek, Yasser B.; Mohamed, Gehan Y.; Mostafa, A. M. A.; Shokry Hassan, H.

    2017-03-01

    Glass samples with the chemical formula x CKD-(100 - x) (5Na2O-65 B2O3-9 Bi2O3-21PbO), (0 ⩽ x ⩽ 32 mol%) were prepared. The density and the ultrasonic estimations of the investigated glasses were analyzed at room temperature before and after the impact of two dosages of gamma irradiation to study the effect of both CKD and gamma radiation. It was found that the density, and the ultrasonic parameters are sensitive to the variety of the content of CKD and the effect of γ-radiation. Replacement of oxides with higher atomic weights such as Bi2O3 and PbO by CKD decreases the density. Analysis of the behavior of the ultrasonic parameters demonstrates that creation of CaO6 and SiO4 on one hand and an alternate transformation between BO4 and BO3 structural units, on the other hand, affect the increase of the ultrasonic velocities and the elastic moduli. Moreover, the density and the ultrasonic parameters decrease somewhat with the increase of the doses of γ-irradiation. The variations of the previous physical parameters can be referred to the creation of radiation imperfections, which occupied the voids inside the glass structure.

  2. Process development for utilizing asbestos cement waste in rotary kilns for the cement industry. Final report; Erarbeitung eines Verfahrens zur stofflichen Verwertung von zementgebundenen Asbestprodukten in Drehrohroefen fuer die Zementindustrie. Abschlussbericht

    Schlegel, R.; Kieser, J.; Kraehner, A.

    1999-11-01

    The law for recycling and waste demands the utilization also for waste of asbestos cement (ac). The procedure of thermal utilization of ac in the flame of a rotary cement kiln was developed and patented by the research institute IBU-tec Weimar, Germany. The ac-material has to be pre-pulverized and grinded to a degree of fineness of R{sub 90}<15%. Considerations of safety engineering lead to the idea of common fine grinding of old oil (oo) and ac. This new procedure was searched in FuE-project in 1998/99 (financial support by BMBF). A mash of ac and oo was generated as a utilization product ready for firing which was injected into the flame of the rotary cement kiln. This particles of ac smelt to spherical shaped particles at a temperature above 1500 C. They were utilized by clinker formation. The material and gas stream leaving the kiln does not contain fibres of asbestos. This was demonstrated in a small equipment burning test. The industrial realization concerning cement plant Ruedersdorf, near Berlin, was searched, technologically described and safety engineeringly and financially assessed by a project study. Process-technical and financial advantages were seen for the dry fine grinding. The wet fine grinding with old oil could be used in cement plants using old oil as fuel. (orig.) [German] Das Kreislaufwirtschafts- und Abfallgesetz (1994) fordert u.a. die stoffliche Verwertung auch fuer Asbestzementabfaelle (AZ). Das vom Institut fuer Baustoff- und Umweltschutz-Technologie Weimar 1995 entwickelte und patentierte Verfahren zur thermischen Verwertung von AZ in der Flamme eines Zementdrehrohrofens erfuellt diese Forderung. Das AZ-Material muss vorzerkleinert und bis zur Rohmehlfeinheit (R{sub 90}<15%) feingemahlen werden. Sicherheitstechnische Ueberlegungen fuehrten zu der Idee, die Feinmahlung zusammen mit Altoel (AOe) zu erproben. Diese Verfahrensvariante wurde im Rahmen eines FuE-Projektes 1998/99 untersucht (finanzielle Foerderung durch das BMBF). Als

  3. Development of electro fused aggregates for use in refractories for the burning zone of cement kilns; Desenvolvimento de agregados eletrofundidos para utilizacao em refratarios para a zona de queima de fornos de cimento

    Ferreira, Luis Leonardo Horne Curimbaba

    2006-07-01

    Electro fused aggregates are largely used in refractory production due to the better performance reached when they are employed. In this work electro fused aggregates were designed for application in refractories for the burning zone of cement kilns. Initially reaction evaluation was conducted aiming the identification of the most prone refractory systems when single refractory phases react with Portland cement phases at high temperatures. In the next step, raw materials of the best refractory systems were electro fused to generate different aggregate compositions. The electro fused aggregates properties were evaluated and the classified ones were used to produce refractory bricks for the burning zone of cement kilns. General characteristics of these bricks were measured and compared with a standard magnesia-spinel refractory. Aggregates of the system Mg O - TiO{sub 2} - Ca O, more specifically aggregates belonged to the compatibility triangle Mg O - Mg{sub 2}TiO{sub 4} - CaTiO{sub 3}, showed suitable characteristics for development of refractories for the burning zone cement kilns. (author)

  4. Biomonitoring spatial and temporal impact of atmospheric dust from a cement industry

    Branquinho, Cristina; Gaio-Oliveira, Gisela; Augusto, Sofia; Pinho, Pedro; Maguas, Cristina; Correia, Otilia

    2008-01-01

    The objective of this work was to evaluate the spatial and temporal impact of dust-pollution in the vicinity of a cement industry, located in an area with dry climate. The spatial impact integrated over time was evaluated from the concentrations of Ca, Fe and Mg in in-situ Xanthoria parietina. The temporal pattern was assessed through one-month transplants of the lichen Ramalina canariensis. Four potential sources of atmospheric dust were evaluated: the limestone-quarry; the unpaved roads, the deposit area and the cement mill. Calcium concentration in lichens was considered the best cement-dust indicator. Different types of dust (clinker and grinded-limestone-dust) resulted in different time-patterns of Ca accumulation, which was also related with the different influence that wet and dry periods have in the lichen accumulation process. The dust pollution was found to be deposited locally and dependent on: the nature of dust particles and the volume and frequency of precipitation. - Biomonitoring Spatial and Temporal dust emissions in dry climates

  5. Biomonitoring spatial and temporal impact of atmospheric dust from a cement industry

    Branquinho, Cristina [Universidade de Lisboa, Faculdade de Ciencias, Centro de Ecologia e Biologia Vegetal, Campo Grande, Edificio C2, Piso 4, 1749-016 Lisbon (Portugal); Universidade Atlantica, Antiga Fabrica da Polvora de Barcarena, 2745-615 Barcarena (Portugal)], E-mail: cmbranquinho@fc.ul.pt; Gaio-Oliveira, Gisela; Augusto, Sofia; Pinho, Pedro; Maguas, Cristina; Correia, Otilia [Universidade de Lisboa, Faculdade de Ciencias, Centro de Ecologia e Biologia Vegetal, Campo Grande, Edificio C2, Piso 4, 1749-016 Lisbon (Portugal)

    2008-01-15

    The objective of this work was to evaluate the spatial and temporal impact of dust-pollution in the vicinity of a cement industry, located in an area with dry climate. The spatial impact integrated over time was evaluated from the concentrations of Ca, Fe and Mg in in-situ Xanthoria parietina. The temporal pattern was assessed through one-month transplants of the lichen Ramalina canariensis. Four potential sources of atmospheric dust were evaluated: the limestone-quarry; the unpaved roads, the deposit area and the cement mill. Calcium concentration in lichens was considered the best cement-dust indicator. Different types of dust (clinker and grinded-limestone-dust) resulted in different time-patterns of Ca accumulation, which was also related with the different influence that wet and dry periods have in the lichen accumulation process. The dust pollution was found to be deposited locally and dependent on: the nature of dust particles and the volume and frequency of precipitation. - Biomonitoring Spatial and Temporal dust emissions in dry climates.

  6. Emissions of metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs) from Portland cement manufacturing plants: inter-kiln variability and dependence on fuel-types.

    Zemba, Stephen; Ames, Michael; Green, Laura; Botelho, Maria João; Gossman, David; Linkov, Igor; Palma-Oliveira, José

    2011-09-15

    Emissions from Portland cement manufacturing facilities may increase health risks in nearby populations and are thus subject to stringent regulations. Direct testing of pollutant concentrations in exhaust gases provides the best basis for assessing the extent of these risks. However, these tests (i) are often conducted under stressed, rather than typical, operating conditions, (ii) may be limited in number and duration, and (iii) may be influenced by specific fuel-types and attributes of individual kilns. We report here on the results of more than 150 emissions-tests conducted of two kilns at a Portland cement manufacturing plant in Portugal. The tests measured various regulated metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs). Stack-gas concentrations of pollutants were found to be highly variable, with standard deviations on the order of mean values. Emission rates of many pollutants were higher when coal was used as the main kiln fuel (instead of petroleum coke). Use of various supplemental fuels, however, had little effect on stack emissions, and few statistically significant differences were observed when hazardous waste was included in the fuel mix. Significant differences in emissions for some pollutants were observed between the two kilns despite their similar designs and uses of similar fuels. All measured values were found to be within applicable regulatory limits. Published by Elsevier B.V.

  7. Cement dust exposure-related emphysema in a construction worker

    V Karkhanis

    2011-01-01

    Full Text Available Although, smoking is considered the most important predisposing factor in development of emphysema; environmental exposures also play an important role. There have been several studies on work related respiratory symptoms and ventilatory disorders among employees of cement industry. We report a case of cement exposure related emphysema in 75 years old woman construction worker.

  8. Leaf structural traits of tropical woody species resistant to cement dust.

    Siqueira-Silva, Advanio Inácio; Pereira, Eduardo Gusmão; Modolo, Luzia Valentina; Paiva, Elder Antonio Sousa

    2016-08-01

    Cement industries located nearby limestone outcrops in Brazil have contributed to the coating of cement dust over native plant species. However, little is known about the extent of the response of tropical woody plants to such environmental pollutant particularly during the first stages of plant development and establishment. This work focused on the investigation of possible alterations in leaf structural and ultrastructural traits of 5-month-old Guazuma ulmifolia Lam. (Malvaceae), 6-month-old Myracrodruon urundeuva Allemão (Anacardiaceae), and 9-month-old Trichilia hirta L. (Meliaceae) challenged superficially with cement dust during new leaf development. Leaf surface of plants, the soil or both (leaf plus soil), were treated (or not) for 60 days, under controlled conditions, with cement dust at 2.5 or 5.0 mg cm(-2). After exposure, no significant structural changes were observed in plant leaves. Also, no plant death was recorded by the end of the experiment. There was also some evidence of localized leaf necrosis in G. ulmifolia and T. hirta, leaf curling in M. urundeuva and T. hirta, and bulges formation on epidermal surface of T. hirta, after cement dust contact with plant shoots. All species studied exhibited stomata obliteration while T. hirta, in particular, presented early leaf abscission, changes in cellular relief, and organization and content of midrib cells. No significant ultrastructural alterations were detected under the experimental conditions studied. Indeed, mesophyll cells presented plastids with intact membrane systems. The high plant survival rates, together with mild morphoanatomic traits alterations in leaves, indicate that G. ulmifolia is more resistant to cement dust pollutant, followed by M. urundeuva and T. hirta. Thus, the three plant species are promising for being used to revegetate areas impacted by cement industries activities.

  9. Impact of cement dust on the mineral and energy concentration of Psidium guayava

    Lai, B.; Ambasht, R.S.

    1982-12-01

    The impact of cement dust deposition on mineral and energy concentration of leaves of guava Psidium guayava growing in the vicinity of Churk Dement Factory situated at Churk, District-Mirzapur (India) was studied. Concentrations of calcium (Ca), potassium (K), sodium (Na) and phosphorus (P) were increased while energy content (cal g/sup -1/ dry weight) was reduced (12.3%) more in cement-dust-covered leaves than in dust-free leaves of Psidium guayava. Statistically it was found that the difference in the concentration of Ca, K, and P industry and dust-free leaves was highly correlated and significant with the amount of cement dust deposited (gm/sup -2/ leaf surface) on the leaf surface of P. guayava while the difference in the concentration of Na--although positively correlated--is not significant. Maximum values of concentrations of Ca, K, Na, P and energy were 5.20%, 0.48%, 0.025%, 0.15% and 4936.7 cal g/sup -1/ dry weight in dust-covered leaves and 3.50%, 0.30%, 0.018%, 0.12% and 5301.4 cal g/sup -1/ dry weight in dust-free leaves, respectively.

  10. Scattering Matrix for Typical Urban Anthropogenic Origin Cement Dust and Discrimination of Representative Atmospheric Particulates

    Liu, Jia; Zhang, Yongming; Zhang, Qixing; Wang, Jinjun

    2018-03-01

    The complete scattering matrix for cement dust was measured as a function of scattering angle from 5° to 160° at a wavelength of 532 nm, as a representative of mineral dust of anthropogenic origin in urban areas. Other related characteristics of cement dust, such as particle size distribution, chemical composition, refractive index, and micromorphology, were also analyzed. For this objective, a newly improved apparatus was built and calibrated using water droplets. Measurements of water droplets were in good agreement with Lorenz-Mie calculations. To facilitate the direct applicability of measurements for cement dust in radiative transfer calculation, the synthetic scattering matrix was computed and defined over the full scattering angle range from 0° to 180°. The scattering matrices for cement dust and typical natural mineral dusts were found to be similar in trends and angular behaviors. Angular distributions of all matrix elements were confined to rather limited domains. To promote the application of light-scattering matrix in atmospheric observation and remote sensing, discrimination methods for various atmospheric particulates (cement dust, soot, smolder smoke, and water droplets) based on the angular distributions of their scattering matrix elements are discussed. The ratio -F12/F11 proved to be the most effective discrimination method when a single matrix element is employed; aerosol identification can be achieved based on -F12/F11 values at 90° and 160°. Meanwhile, the combinations of -F12/F11 with F22/F11 (or (F11 - F22)/(F11 + F22)) or -F12/F11 with F44/F11 at 160° can be used when multiple matrix elements at the same scattering angle are selected.

  11. Dust exposure and the risk of cancer in cement industry workers in Korea.

    Koh, Dong-Hee; Kim, Tae-Woo; Jang, Seunghee; Ryu, Hyang-Woo

    2013-03-01

    Cement is used widely in the construction industry, though it contains hazardous chemicals such as hexavalent chromium. Several epidemiological studies have examined the association between cement dust exposure and cancer, but these associations have proved inconclusive. In the present study, we examined the association between dust exposure and cancer in cement industry workers in Korea. Our cohort consisted of 1,324 men who worked at two Portland cement manufacturing factories between 1997 and 2005. We calculated cumulative dust exposures, then categorized workers into high and low dust exposure groups. Cancer cases were identified between 1997 and 2005 by linking with the national cancer registry. Standardized incidence ratios (SIRs) were calculated for all workers and the high and low dust exposure groups, respectively. The SIR for overall cancers in all workers was increased (1.35, 95% CI: 1.01-1.78). The SIR for stomach cancer in the high dust exposure group was increased (2.18, 95% CI: 1.19-3.65), but there was no increased stomach cancer risk in the low dust exposure group. The SIR for rectal cancer in all workers was increased (3.05, 95% CI: 1.32-6.02). Rectal cancer risk was similar in the high and low exposure groups. Our findings suggest a potential association between exposure in the cement industry and an increased risk of stomach and rectal cancers. However, due to the small number of cases, this association should be further investigated in a study with a longer follow-up period and adjustment for confounders. Copyright © 2012 Wiley Periodicals, Inc.

  12. Use of secondary fuels in rotary kilns of the cement industry; Einsatz von Sekundaerstoffen in Drehofenanlagen der Zementindustrie

    Hoenig, V. [Forschungsinstitut der Zementindustrie, Duesseldorf (Germany)

    1998-09-01

    Most cement works in Germany use secondary materials for cement production or are planning to do so. Many of the materials in question, such as used tyres, have been recycled in an environmentally acceptable way for decades, and a large body of experience has accumulated on their use in the cement industry. In the cement industry secondary materials are understood to comprise secondary fuels as well as secondary raw materials. The latter have for some part replaced the natural raw materials used for burning cement clinker, the preliminary product of cement. By using used tyres, used oil and other waste materials as secondary fuels the cement industry has for decades contributed to an environmentally acceptable form of waste disposal. The use of secondary materials has also enabled the cement industry to improve its economic situation. In response to the enactment of the Materials Recycling Law the cement industry has during the past few years turned its attention to the utilisation of other waste materials. The criteria relevant to the cement industry`s choice of a waste material as secondary material lastly depends on the process-related side constraints attending the clinker burning process and the requirements on the burning process with regard to product quality and environmental acceptability. [Deutsch] Die meisten Zementwerke in Deutschland setzen bei der Zementherstellung Sekundaerstoffe ein oder planen ihren Einsatz. Fuer einige dieser Stoffe, wie z.B. Altreifen gilt, dass sie bereits seit Jahrzehnten umweltvertraeglich verwertet werden, so dass viele Erfahrungen ueber deren Einsatz in der Zementindustrie vorliegen. Unter Sekundaerstoffen werden in der Zementindustrie sowohl Sekundaerbrennstoffe wie auch Sekundaerrohstoffe verstanden. Letztere ersetzen teilweise die natuerlichen Rohstoffe, aus denen der Zementklinker, das Vorprodukt des Zements, gebrannt wird. Bezueglich der Sekundaerbrennstoffe traegt die Zementindustrie schon seit Jahrzehnten zu einer

  13. Cement dust exposure and acute lung function: A cross shift study

    Moen Bente E

    2010-04-01

    Full Text Available Abstract Background Few studies have been carried out on acute effects of cement dust exposure. This study is conducted to investigate the associations between current "total" dust exposure and acute respiratory symptoms and respiratory function among cement factory workers. Methods A combined cross-sectional and cross-shift study was conducted in Dire Dawa cement factory in Ethiopia. 40 exposed production workers from the crusher and packing sections and 20 controls from the guards were included. Personal "total" dust was measured in the workers' breathing zone and peak expiratory flow (PEF was measured for all selected workers before and after the shift. When the day shift ended, the acute respiratory symptoms experienced were scored and recorded on a five-point Likert scale using a modified respiratory symptom score questionnaire. Results The highest geometric mean dust exposure was found in the crusher section (38.6 mg/m3 followed by the packing section (18.5 mg/m3 and the guards (0.4 mg/m3. The highest prevalence of respiratory symptoms for the high exposed workers was stuffy nose (85% followed by shortness of breath (47% and "sneezing" (45%. PEF decreased significantly across the shift in the high exposed group. Multiple linear regression showed a significant negative association between the percentage cross-shift change in PEF and total dust exposure. The number of years of work in high-exposure sections and current smoking were also associated with cross-shift decrease in PEF. Conclusions Total cement dust exposure was related to acute respiratory symptoms and acute ventilatory effects. Implementing measures to control dust and providing adequate personal respiratory protective equipment for the production workers are highly recommended.

  14. Lung function and long-term exposure to cement dust

    Rasmussen, F V; Borchsenius, L; Holstein, B

    1977-01-01

    occupational category. Each occupational category was further subdivided according to smoking habits and in all categories the well-known association between tobacco consumption and decrease in ventilatory capacity was found. White collar workers, who smoke less and had experienced better housing conditions...... throughout life had better ventilatory lung function than any of the other three occupational categories. No significant differences in lung function between cement factory workers and other blue collar workers with comparable smoking habits could be demonstrated by use of the maximal midexpiratory flow...

  15. Manufacturing of wollastonite-based glass from cement dust: Physical and mechanical properties

    A.A. Francis

    2016-12-01

    Full Text Available By-pass cement dust is considered as a source of environmental pollution. Wollastonite-based glass foams are made by adding glass waste and SiC to the cement dust. XRD on samples indicated that the main crystalline phase after heat treatment at 850–1,000°C is wollastonite. Empirical models were developed to derive conclusion on the impact of SiC and temperature on the physical and mechanical properties of the products. The optimum sintering temperature was found to be at 900°C for 60 min, at which crushing strength was about 15 MPa and was the best uniform. Such wollastonite-based glass foam could be very attractive for thermal and acoustic applications.

  16. Effect of Addition of A Marble Dust on Drying Shrinkage Cracks of Cement Mortar Reinforced with Various Fibers

    Basim Thabit Al-Khafaji

    2017-05-01

    Full Text Available This investigation is conducted to study the effect of addition of marble powder (marble dust and different fibers on drying shrinkage cracks and some properties of fibers reinforcment cement mortar. Steel molds having a trapezoidal section, and the end restrained at square shape with( 2.7 meter at length are used to study restrained drying shrinkage of cement mortar. Specimens of ( compressive .flextural. splitting strength were cast. The admixture (marble dust was used to replacie weight of cement with three levels of (4%, 8% and 16% and the fiber hemp and sisal fiber were added for all mixes with proportion by volum of cement . All specimens were cured for (14 days. Average of three results was taken for any test of compressive, tensil and flextural strength. The experimental results showed that the adding of this admixture(marble dust cause adelay in a formation of cracks predicted from a drying shrinkage ,decreases of its width , and hence increases of (compressive, splitting tensil and flextural strength at levels of (4%, and 8%. Thus there is a the positive effect when fiberes added for all mixes of cement mortar with addition of (marble dust. All The admixtures (marble dust and fibers have the obvious visible effect in the delay of the information of shrinkage cracks and the decrease of its width as Compared to the cement mortar mixes when marble dust added a alone.

  17. Reliability estimate of unconfined compressive strength of black cotton soil stabilized with cement and quarry dust

    Dayo Oluwatoyin AKANBI

    2017-06-01

    Full Text Available Reliability estimates of unconfined compressive strength values from laboratory results for specimens compacted at British Standard Light (BSLfor compacted quarry dust treated black cotton soil using cement for road sub – base material was developed by incorporating data obtained from Unconfined compressive strength (UCS test gotten from the laboratory test to produce a predictive model. Data obtained were incorporated into a FORTRAN-based first-order reliability program to obtain reliability index values. Variable factors such as water content relative to optimum (WRO, hydraulic modulus (HM, quarry dust (QD, cement (C, Tri-Calcium silicate (C3S, Di-calcium silicate (C2S, Tri-Calcium Aluminate (C3A, and maximum dry density (MDD produced acceptable safety index value of1.0and they were achieved at coefficient of variation (COV ranges of 10-100%. Observed trends indicate that WRO, C3S, C2S and MDD are greatly influenced by the COV and therefore must be strictly controlled in QD/C treated black cotton soil for use as sub-base material in road pavements. Stochastically, British Standard light (BSL can be used to model the 7 days unconfined compressive strength of compacted quarry dust/cement treated black cotton soil as a sub-base material for road pavement at all coefficient of variation (COV range 10 – 100% because the safety index obtained are higher than the acceptable 1.0 value.

  18. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  19. Study of air pollution with cement dust and its effect on plants cover in the surrounding area of Tartous cement factory

    Meslmani, Y.; Al-Oudat, M.; Al-Kharfan, K.

    2000-06-01

    Cement dust fall, concentration of total suspended particulate (TSP) and particulate less than 10 micron (PM10), were measured in different sites in the surrounding area of Tartus cement factory. The effects of cement dust emission on the growth of olive trees have been investigated. The results show that the dust fall, TSP and PM10 concentration were higher than The World Health Organization (WHO) standard at the factory site as well as in the surrounding area within 3 to 4 km in the diameter.The study shows that, the cement dust fall decreases the growth of olive trees by 34.5, 33 and 21% regarding the I, II, III sites respectively in comparison with the reference site. The branch length, branch weight, amount of chlorophyll and leaves quantity were decreased significantly. The mean weight of dust fall were 34.5, 26.4 and 10.9 g/m 2 on the leaves area at the site I, II, III respectively while the reference site has a value of 1.9 g/m 2 .(Author)

  20. Study of air pollution with cement dust and its effect on plants cover in the surrounding area of Tartous cement factory

    Meslmani, Y; Al-Oudat, M; Al-Kharfan, K [Atomic Energy Commission, Damascus (Syrian Arab Republic). Dept. of Protection and Safety

    2000-06-01

    Cement dust fall, concentration of total suspended particulate (TSP) and particulate less than 10 micron (PM10), were measured in different sites in the surrounding area of Tartus cement factory. The effects of cement dust emission on the growth of olive trees have been investigated. The results show that the dust fall, TSP and PM10 concentration were higher than The World Health Organization (WHO) standard at the factory site as well as in the surrounding area within 3 to 4 km in the diameter.The study shows that, the cement dust fall decreases the growth of olive trees by 34.5, 33 and 21% regarding the I, II, III sites respectively in comparison with the reference site. The branch length, branch weight, amount of chlorophyll and leaves quantity were decreased significantly. The mean weight of dust fall were 34.5, 26.4 and 10.9 g/m{sup 2} on the leaves area at the site I, II, III respectively while the reference site has a value of 1.9 g/m{sup 2}.(Author)

  1. Baking of the multi-itemed clinker by the large kiln; Ogata kirun ni yoru tahinshu kurinka no shosei

    Kihara, Yasuhiro [Ube Industies, Ltd., Yamaguchi (Japan)

    1998-10-10

    In the Ube cement plant, it had 5 DB kilns, and it became a base of the special cement manufacture. However, the productivity difference with the special cement manufacture by the large kiln recently spread, and in the DB cairn, it was judged with the limit. Therefore, the rationalization which put together DB kiln of 5 in NSP kiln of 1 was carried out, while the role of the special cement manufacture base was maintained. In this paper, the outline of variety switching technology in large and single kiln of 1 for the multi-itemed and multi-itemed clinker production is introduced in this. (NEDO)

  2. Status quo of energy recovery from waste in special industrial facilities and evaluation of the environmental impacts of using refuse derived fuel (RDF) in cement kilns in Germany; Untersuchung der Umweltauswirkungen des Einsatzes von Abfaellen ausserhalb thermischer Abfallbehandlungsanlagen

    Alwast, H.; Marton, C.; Koepp, M.

    2001-10-01

    Within the study presented here the use of energy recovery from waste was analysed for several industrial facilities, focussing on cement plants, kilns in the lime and gypsum industry, steel works and plants for the production of non ferrous metals. 44 German cement plants dispose of an own clinker production. Presently 31 plants have a permit for recovering energy from waste. The total permitted capacity for energy recovery in German cement kilns amounts to nearly 2,6 Mio. t/a. Mainly waste oil, old tyres, fuel derived from processed production-specific and municipal waste, plastics, scrap wood and waste paper are co-incinerated. In 1998/99 a total amount of roughly 945.000 t refuse was processed in 30 units of the studied facilities. In five furnaces at three steel works waste can be used for energy or material recovery. The approved total capacity of high calorific waste for energy recovery comes to nearly 350,000 t/a. Especially industrial plastics and packaging waste from DSD, plastics processed in scrap mills and shreddered waste and granulated paint sludge are used. In 1998 the facilities processed only old plastic, representing a total amount of nearly 109.000 t. At present seven facilities in the non ferrous metal industry have a permit for energy recovery from waste. The maximum capacity amounts on national level to nearly 140.000 t/a. Especially waste oil, packaging waste, plastics and scrap wood can be processed. The analysis of respective applications of the 17th BImSchV shows an inconsistency within the amending permitting procedures. For the time to come a conformity between the respective regional permitting authorities would be recommendable. Moreover, the effects on air emission caused by using waste for energy recovery were analysed for cement kilns with own clinker production. Due to the amendment of the 17th BImSchV more stringent requirements regarding waste composition must be established. This is especially valid for the highly volatile

  3. Dust Full Study In The Surrounding Area Of A Cement Factory And Determination Of The Major Elements Of The Dust Fall Using Neutron Activation Analysis (NAA)

    Meslmani, Y.; Al-Oudat, M.

    2004-01-01

    Dust fall of the Tartous cement factory and the surrounding area at the Syrian coast were measured. The results show that the dust fall concentrations were higher than the World Health Organization (WHO) Standard in the factory site as well as in the surrounding area within 5 to 6 km in the diameter. The value of the dust fall at the Reference sites was abut 4.5 t/km 2 /month and in the surrounding area of the factory values reached between 18 and 120 t/km 2 /month. This means the values exceed the standard around 3 and 13 times. The Neutron Activation Analysis (NAA) of cement dust showed a percentage of 27.5% ± 1.6 of calcium. By the presence of humidity calcium silicate occurs, which immediately dries and becomes a hard salt crust. Therefore in the regions near by the factory cement dust formed this kind of salt coat on the surface of the leaves. (Authors)

  4. Cement Formation

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

  5. Numerical Modeling of Rotary Kiln Productivity Increase

    Romero-Valle, M.A.; Pisaroni, M.; Van Puyvelde, D.; Lahaye, D.J.P.; Sadi, R.

    2013-01-01

    Rotary kilns are used in many industrial processes ranging from cement manufacturing to waste incineration. The operating conditions vary widely depending on the process. While there are many models available within the literature and industry, the wide range of operating conditions justifies

  6. FEASIBILITY ANALYSIS ON INDUSTRIAL SYMBIOSIS BETWEEN CEMENT INDUSTRY AND TEA INDUSTRY

    Shailendra Kumar Yadav

    2015-08-01

    Full Text Available The project aims at analyzing the feasibility of utilizing cement kiln dust (CKD in treating wastewater from tea industry with the concept of industrial symbiosis. CKD is the dust collected at the air pollution control device(s associated with a kiln system from cement industry. A very less percent of CKD is recycled and the rest is land filled /stockpiled; disrupts groundwater through leaching of minerals. Cement Kiln Dust (CKD, rich in CaO, SiO2, behaves as a neutralizing as well as stabilizing agent for tea effluent treatment. The ability of CKD to reduce the BOD, COD, TSS, and phosphates in tea effluent was analyzed and the optimum dosage is determined. The effect of different dosages of Cement Kiln Dust ranging from (1-3 gm/l has been discussed on the bench scale tests. The results show that, for different CKD concentrations, high removal efficiencies of 94.4 and 99.0, 58.9 for BOD, TSS, phosphates and a lower efficiency for COD with 9.09 are achieved for 2.5gm/l. The persistent presence of color providing proteins theaflavins (TF and the arubigins (TR from the leftover tea leaves in the effluent imparts the low removal efficiencies of COD. However, the COD value is within the dischargeable limits (CPCB standards. Moreover, a considerable removal efficiency and high SVI of 0.181 makes CKD a feasible coagulant in treating tea effluent with optimum dosage of 2.5g/l. The objective of developing industrial symbiosis network was thus achieved using the CKD to treat wastewater from tea industries.   International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 20-34

  7. Raw mix designing for coal as a fuel in cement kiln as a major fuel and its impact on clinker parameters

    Noor-ul-Amin; Ali, K.

    2011-01-01

    In this paper the use of coal, found at Jabba Taar and Jabba Khushk Khyber Pakhtoon Khwa, in cement manufacturing as a major fuel and its impacts on the raw mix and clinker parameters has been discussed. The maximum amount of coal for pulverizing with raw mix was found to be 10% of the raw mix as calculated from the calorific value and the heat of clinkerization of coal. The coal residue left after burning was utilized in the cement raw material, for which a new raw mix was designed. The new raw mix was converted in to clinker. The resulting clinker was studied for all parameters as per British specification. It was found that the clinker obtained from the newly designed raw mix with coal ash, was in accordance to the British standard specifications. (author)

  8. Relationships between Personal Measurements of 'Total' Dust, Respirable, Thoracic, and Inhalable Aerosol Fractions in the Cement Production Industry.

    Notø, Hilde P; Nordby, Karl-Christian; Eduard, Wijnand

    2016-05-01

    The aims of this study were to examine the relationships and establish conversion factors between 'total' dust, respirable, thoracic, and inhalable aerosol fractions measured by parallel personal sampling on workers from the production departments of cement plants. 'Total' dust in this study refers to aerosol sampled by the closed face 37-mm Millipore filter cassette. Side-by-side personal measurements of 'total' dust and respirable, thoracic, and inhalable aerosol fractions were performed on workers in 17 European and Turkish cement plants. Simple linear and mixed model regressions were used to model the associations between the samplers. The total number of personal samples collected on 141 workers was 512. Of these 8.4% were excluded leaving 469 for statistical analysis. The different aerosol fractions contained from 90 to 130 measurements and-side-by side measurements of all four aerosol fractions were collected on 72 workers.The median ratios between observed results of the respirable, 'total' dust, and inhalable fractions relative to the thoracic aerosol fractions were 0.51, 2.4, and 5.9 respectively. The ratios between the samplers were not constant over the measured concentration range and were best described by regression models. Job type, position of samplers on left or right shoulder and plant had no substantial effect on the ratios. The ratios between aerosol fractions changed with different air concentrations. Conversion models for estimation of the fractions were established. These models explained a high proportion of the variance (74-91%) indicating that they are useful for the estimation of concentrations based on measurements of a different aerosol fraction. The calculated uncertainties at most observed concentrations were below 30% which is acceptable for comparison with limit values (EN 482, 2012). The cement industry will therefore be able to predict the health related aerosol fractions from their former or future measurements of one of the

  9. Reducing cement's CO2 footprint

    van Oss, Hendrik G.

    2011-01-01

    The manufacturing process for Portland cement causes high levels of greenhouse gas emissions. However, environmental impacts can be reduced by using more energy-efficient kilns and replacing fossil energy with alternative fuels. Although carbon capture and new cements with less CO2 emission are still in the experimental phase, all these innovations can help develop a cleaner cement industry.

  10. Dictionary of cement. Manufacture and technology. German-English. English-German. 2. Rev. and enlarged Ed. Zementwoerterbuch. Herstellung und Technologie. Deutsch-Englisch. Englisch-Deutsch

    Van Amerongen, C

    1986-01-01

    This book deals with the following fields: cement chemistry; chemical and physical testing; quarrying (drilling, blasting, excavating and loading machinery, haulage vehicles); crushing and grinding; sampling; materials handling; blending, homogenizing, storage (blending beds, silos); kilns, preheaters, precalciners; firing technology (fuels, burners); refractories; clinker coolers; air separators (classifiers); dust collecting equipment (filters, electrostatic precipitators); air pollution and noise control; bulk handling installations; sack packing machines; packaging, palletizing, dispatch.

  11. Energy saving plan for lime calcining kiln

    NONE

    2000-03-01

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

  12. A coincineração de resíduos em fornos de cimento: riscos para a saúde e o meio ambiente Co-incineration in cement kilns: health and environmental risks

    Bruno Milanez

    2009-12-01

    Full Text Available O objetivo do artigo é discutir a forma como a coincineração de resíduos em fábricas de cimento vem crescendo no Brasil, bem como seus impactos sobre a saúde humana e o meio ambiente. Informações gerais sobre mercado e efeitos sobre a saúde foram obtidas através de revisão bibliográfica e alguns estudos de caso, escolhidos a partir de debate com integrantes da Rede Brasileira de Justiça Ambiental, foram construídos para ilustrar a situação no Brasil. Os estudos encontrados mostraram que, independente do nível de desenvolvimento tecnológico dos países, a saúde dos trabalhadores e das pessoas que moram próximas às fábricas de cimento vem sendo prejudicada pela poluição emitida pelas empresas de cimento, em especial por aquelas que praticam a coincineração. Além disso, no contexto brasileiro, a vulnerabilidade das instituições e populações afetadas tende a agravar este problema. Como conclusão, defende-se o aumento da capacidade institucional dos órgãos brasileiros responsáveis pelo monitoramento das atividades industriais, bem como uma rediscussão mais aprofundada dos aspectos políticos e éticos ligados ao transporte e comércio de resíduos industriais.In this article we discuss the development of hazardous waste co-incineration in cement kilns in Brazil as well as its impacts on health and the environment. Information was gathered through an extensive review on social and environmental impacts of co-incineration, and case studies, chosen after discussion with social movement representatives concerned with the co-incineration issue and related to the Brazilian Network on Environmental Justice, are described to illustrate the reality of co-incineration in Brazil. Studies showed that workers and community health suffers negative impacts from such practices in high-, middle- and low-income countries. In the Brazilian context, the institutional and social vulnerability intensifies these problems. To conclude, we

  13. The Distribution of PM10 and PM2.5 Dust Particles Diameter in Airborne at the Cement Factory Neighboring Area, Citeureup - Bogor

    Gatot Suhariyono; Muji Wiyono

    2003-01-01

    The distribution analysis in PM 10 and PM 2.5 dust particle diameter has been carried out at residence area around the cement factory, Citeureup - Bogor to estimate deposition of dust particles that is accepted by public. The dust particles were sampled at the dwellings by using a cascade impactor on four wind directions and 500, 1000, 1500, 2000, 2500, and 3000 m radius from the Plant one as the center of the cement factory at Citeureup - Bogor. Measurements at the north direction were the Gunung Putri, Kranggan, Bojong Nangka villages, and Gunung Putri dwellings. The south directions were Tarikolot and Pasir Mukti villages. The west directions were guest house, Puspanegara, Puspasari, and Citatah villages. The northwest directions were Puspanegara, Gunung Putri, Puspasari, and Kranggan villages. The analysis result showed that the diameter distribution of PM 10 dust particles at outdoor is ranging from 0.4 to 4.7 μm, and has the weight percentage is high in average approximate 17.91 % of total dust weight on 500, 1000, 1500, 2000, 2500, and 3000 m radius. The distributions of indoor PM 2.5 dust particles diameter show a stable 12.27 % weight percentage of total dust weight from 0.4 to 2.1 μm. (author)

  14. Rotary kiln arrangements

    Hayes, M.R.

    1983-01-01

    In a rotary kiln arrangement in which a reaction is to occur between counterflowing reactants and material is discharged through a hopper, an injector for at least one reactant extends into a reaction zone of the kiln, means being provided for the reaction zone to be maintained within a desired temperature range. The said means includes heating elements for adjusting the temperature of the injected reactant to a temperature within the desired range while it is in the injector. The arrangement may be used in the production of uranium oxides from uranium hexafluoride. (author)

  15. Alternative Fuels in Cement Production

    Larsen, Morten Boberg

    The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted...... for the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability...

  16. Devolatilization and Combustion of Tire Rubber and Pine Wood in a Pilot Scale Rotary Kiln

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

    2012-01-01

    Cement production is highly energy intensive and requires large quantities of fuels. For both economical and environmental reasons, there is an increasing tendency for utilization of alternative fuels in the cement industry, examples being tire derived fuels, waste wood, or different types...... of industrial waste. In this study, devolatilization and combustion of large particles of tire rubber and pine wood with equivalent diameters of 10 mm to 26 mm are investigated in a pilot scale rotary kiln able to simulate the process conditions present in the material inlet end of cement rotary kilns...

  17. Advanced dust control techniques in cement industry electrostatic precipitator - a case study

    Khattak, Z.; Ahmad, J.

    2011-01-01

    The case study deal with the current day problem of pollution by industrial zones in Pakistan with emphasis on the cement Industry which has been proved to be the second revenue generating hub after textile sector of the Pakistan. A pilot study into the identification and available removal Techniques of particulates from the exhaust of a cement plant clinker cooler was carried out. The objective of this work was to study the performance of the each technique in detail in the removal of a particulate with a wide range of sizes, under different operational conditions and to compare the results for collection efficiency with predictions by available theoretical models. A brief and comprehensive discussion regarding design, construction and bottlenecks of each tool has been discussed to fully ascertain it's scope and usability. First part of the study identifies the various pollutants being emitted from the chimney of a specific cement plant in Pakistan and while last portion deals with the ways to curtail these pollutants. (author)

  18. PO43 Removal by and Permeability of Industrial Byproducts and Minerals: Granulated Blast Furnace Slag, Cement Kiln Dust, Coconut Shell Activated Carbon, Silica Sand and Zeolite

    Excess aqueous concentration of phosphate degrades the overall water quality of the receiving surface waters in a cumulatively damaging process referred to as eutrophication. Adsorption of excess phosphate has proven to be the most effective, and economical methods of phosphate removal from such wat...

  19. Influence of chemical and physical characteristics of cement kiln dusts (CKDs) on their hydration behavior and potential suitability for soil stabilization

    Peethamparan, Sulapha; Olek, Jan; Lovell, Janet

    2008-01-01

    The interaction of CKDs with a given soil depends on the chemical and physical characteristics of the CKDs. Hence, the characterization of CKDs and their hydration products may lead to better understanding of their suitability as soil stabilizers. In the present article, four different CKD powders are characterized and their hydration products are evaluated. A detailed chemical (X-ray diffraction), thermogravimetric and morphological (scanning electron microscope) analyses of both the CKD powders and the hydrated CKD pastes are presented. In general, high free-lime content (∼ 14-29%) CKDs, when reacted with water produced significant amounts of calcium hydroxide, ettringite and syngenite. These CKDs also developed higher unconfined compressive strength and higher temperature of hydration compared to CKDs with lower amounts of free-lime. An attempt was made to qualitatively correlate the performance of CKD pastes with the chemical and physical characteristics of the original CKD powders and to determine their potential suitability as soil stabilizers. To that effect a limited unconfined compressive strength testing of CKD-treated kaolinite clays was performed. The results of this study suggest that both the compressive strength and the temperature of hydration of the CKD paste can give early indications of the suitability of particular CKD for soil stabilization

  20. Assessment of airborne 238U and 232Th exposure and dust load impact on people living in the vicinity of a cement factory in Ghana

    Addo, Moses Ankamah; Gbadago, J.K.; Ameyaw, Felix; Darko, E.O.; Gordon, Chris; Davor, Peter; Faanu, A.; Kpeglo, David

    2014-01-01

    Globally, the cement industry has been identified as one which causes significant particle pollution. In Ghana, environmental research in the neighborhood of the cement industry especially on human health is scanty. In the present work, attempts were made to evaluate the concentration of airborne dust at various distances and directions around the Diamond Cement Factory in the Volta Region of Ghana. The samples of dust were collected on filter papers and later analyzed for the concentration (mg/kg) of 232 Th and 23 '8U using neutron activation analysis. The principal objective of the study was to generate data intended at assessing the annual effective dose due to 232 Th and 238 U inhalation for both adult and children population living in the vicinity of cement factory. The data generated were supposed to assist in remediation decision making, if required. The study recorded a few incidences of higher total dust load concentrations as compared to the permissible limit of 150 μg/m 3 specified by the Ghana Environmental Protection Agency. The calculated mean effective doses were 28.2 ± 1.06 μSv/year and 25.9 ± 0.91 μSv/year for both adult and child, respectively. From the radiological point of view, the study concluded that the people living in the vicinity of the cement factory are not at risk to significant radiological hazards. However, the study indicated the need to have a complete evaluation of the impact of the factory on the environment assessment programs which should include both chemical and radiological toxicity. (author)

  1. Producing cement

    Stone, E G

    1923-09-12

    A process and apparatus are described for producing Portland cement in which pulverized shale is successively heated in a series of inclined rotary retorts having internal stirrers and oil gas outlets, which are connected to condensers. The partially treated shale is removed from the lowermost retort by a conveyor, then fed separately or conjointly into pipes and thence into a number of vertically disposed retorts. Each of these retorts may be fitted interiorly with vertical arranged conveyors which elevate the shale and discharge it over a lip, from whence it falls to the bottom of the retorts. The lower end of each casing is furnished with an adjustable discharge door through which the spent shale is fed to a hopper, thence into separate trucks. The oil gases generated in the retorts are exhausted through pipes to condensers. The spent shale is conveyed to a bin and mixed while hot with ground limestone. The admixed materials are then ground and fed to a rotary kiln which is fired by the incondensible gases derived from the oil gases obtained in the previous retorting of the shale. The calcined materials are then delivered from the rotary kiln to rotary coolers. The waste gases from the kiln are utilized for heating the retorts in which the ground shale is heated for the purpose of extracting therefrom the contained hydrocarbon oils and gases.

  2. Case study: evaluation of continuos blending silos in the cement industry, by the aid of tracer techniques

    Sebastian, C.; Maghella, G.; Mamani, E.

    2000-12-01

    Besides the actual burning process in cement manufacture, particular importance is attached to raw material preparation and homogenization, not only because of the quality of the kiln fed and therefore of the produced cement, but also because of the economy of the kiln operation, which significantly depends on the uniformity of the chemical composition of the material. As a result, the blending process of the cement raw material, before burning, is a basic stage of cement technology production. In this case, the pneumatic homogenization process is studied in a silo with a great storing and processing capacity. The objective is to evaluate the parameters which influence in the continuos operation. The method allows us to determine the optimal blending parameters, through the observation of the movement and distribution of the different fractions of fine dust raw meal, labelled with La-140 as tracer. Changes in blending according to time are discussed as well as the influence of the silo design on the degree of homogenization. It was showed that the silo blending operation has a strong influence on the production of good-quality cement as well as the implications on energy saving

  3. NOx from cement production - reduction by primary measures

    Jensen, Lars Skaarup

    1999-01-01

    cement production processes cement is typically produced by thermally treating a mixture of limestone and clay minerals in kiln systems consisting of a rotary kiln and a calciner. Clinker burning at a temperature of about 1450 °C takes place in the internally fired rotary kiln and calcination, which...... rotary kilns, while NOx formation from fuel-N and reduction of NOx take place in calciners. NOx formation in the rotary kiln is mainly governed by the necessary clinker burning temperature and is not very amenable to control, while net NOx formation in calciners depends strongly on calciner design......, calciner operation, fuel properties and on the NOx level from the rotary kiln. The low-NOx calciner types presently marketed are based on combinations of reburning, air staging and temperature control and seem equivalent in their ability to restrict NOx formation. If fuels with a significant volatile...

  4. Kiln emissions and potters' exposures.

    Hirtle, B; Teschke, K; van Netten, C; Brauer, M

    1998-10-01

    Some ten thousand British Columbia potters work in small private studios, cooperative facilities, educational institutions, or recreation centers. There has been considerable concern that this diffuse, largely unregulated activity may involve exposures to unacceptable levels of kiln emissions. Pottery kiln emissions were measured at 50 sites--10 from each of 5 categories: professional studios, recreation centers, elementary schools, secondary schools, and colleges. Area monitoring was done 76 cm from firing kilns and 1.6 m above the floor to assess breathing zone concentrations of nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes, aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, gold, iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium, silver, vanadium, and zinc. Personal exposures to the same metals were measured at 24 sites. Almost all measured values were well below permissible concentrations for British Columbia work sites and American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) with the following two exceptions. A single firing duration (495 minute) acrolein measurement adjacent to an electric kiln (0.109 ppm) exceeded these guidelines. One 15-minute sulfur dioxide measurement collected adjacent to a gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The fact that concentrations in small, ventilated kiln rooms ranked among the highest measured gives rise to concern that unacceptable levels of contamination may exist where small kiln rooms remain unventilated. Custom designed exhaust hoods and industrial heating, ventilating, and air-conditioning systems were the most effective ventilation strategies. Passive diffusion and wall/window fans were least effective.

  5. 40 CFR 63.1343 - Standards for kilns and in-line kiln/raw mills.

    2010-07-01

    .../raw mills. 63.1343 Section 63.1343 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Industry Emission Standards and Operating Limits § 63.1343 Standards for kilns and in-line kiln/raw mills. (a) General. The provisions in this section apply to each kiln, each in-line kiln/raw mill, and any...

  6. Occupational Health Hazards of Women Working in Brick Kiln and Construction Industry

    V. G Vaidya

    2015-01-01

    Full Text Available Background: In brick kiln and construction industry the exposure to carbon monoxide and silica dust is the most common occupational hazard to the workers in these industries. A study on occupational health hazards of working women in these two unorganized sectors was undertaken by Lokmanya Medical Research Centre. Objectives: To study the effect of work site environment on the health of the women working in brick kiln and construction industry. An attempt was also made to study the seasonal changes in the concentration of carbon monoxide and dust at the worksite. Material and Methods: A cross-sectional study was conducted among the working women (age 18-40 years at brick kilns and construction sites during summer and winter season. They were examined primarily to assess the effect of working environment on health. Gasteck Detector Pump of model 800 and air sampling instrument (SKC Air Check–52 were used to measure concentration of carbon monoxide and dust in the air respectively. Results: There were 66% of women who were in the age group of 18-40 years and most of them (94% were married. At brick kiln sites, average CO exposure was 62.8 ppm and 55.5 ppm and average dust exposure was 3 3 146.1 mg/m and 91.4 mg/m in summer and winter season respectively.At construction sites, average dust exposure was 41.5 ppm and 90.8 ppm in summer and winter. Conclusion: Both exposure to CO and dust were more in summer than in winter in brick kiln industry whereas in construction industry the exposure to dust was more in winter season. A high level of morbidity in the form of headache, bodyache, problems with vision, cough and breathlessness were observed in both industries. It is strongly recommended to take pollution control measures.

  7. A Pottery Electric Kiln Using Decompression

    Naoe, Nobuyuki; Yamada, Hirofumi; Nakayama, Tetsuo; Nakayama, Minoru; Minamide, Akiyuki; Takemata, Kazuya

    This paper presents a novel type electric kiln which fires the pottery using the decompression. The electric kiln is suitable for the environment and the energy saving as the pottery furnace. This paper described the baking principle and the baking characteristic of the novel type electric kiln.

  8. Case study: evaluation of continuos blending silos in the cement industry, by the aid of tracer techniques; Caso de estudio: Evaluacion de silos continuos de homogenizacion en la industria del cemento, utilizando tecnicas de radiotrazadores

    Sebastian, C; Maghella, G; Mamani, E [Direccion de Aplicaciones. Instituto Peruano de Energia Nuclear, Lima (Peru)

    2000-12-01

    Besides the actual burning process in cement manufacture, particular importance is attached to raw material preparation and homogenization, not only because of the quality of the kiln fed and therefore of the produced cement, but also because of the economy of the kiln operation, which significantly depends on the uniformity of the chemical composition of the material. As a result, the blending process of the cement raw material, before burning, is a basic stage of cement technology production. In this case, the pneumatic homogenization process is studied in a silo with a great storing and processing capacity. The objective is to evaluate the parameters which influence in the continuos operation. The method allows us to determine the optimal blending parameters, through the observation of the movement and distribution of the different fractions of fine dust raw meal, labelled with La-140 as tracer. Changes in blending according to time are discussed as well as the influence of the silo design on the degree of homogenization. It was showed that the silo blending operation has a strong influence on the production of good-quality cement as well as the implications on energy saving.

  9. Barium aluminate cement: its application

    Drozdz, M.; Wolek, W.

    1975-01-01

    The technology of manufacturing barium aluminate cement from barium sulfate and alumina, using a rotary kiln for firing the clinker is described. The method of granulation of the homogenized charge was used. Conditions of using the ''to mud'' method in industry were indicated. The physical and chemical properties of barium aluminate cement are determined and the quality of several batches of cement prepared on a semi-industrial scale and their suitability for making highly refractory concretes are tested. The optimal composition of the concretes is determined as a function of the mixing water and barium aluminate cement contents. Several experimental batches of concretes were used in the linings of furnaces in the steel industry. The suitability of these cements for use in fields other than steelmaking is examined. It is established that calcium aluminate cement has certain limited applications [fr

  10. Sulfoaluminate-belite cement from low-calcium fly ash and sulfur-rich and other industrial by-products

    Arjunan, P.; Silsbee, M.R.; Roy, D.M.

    1999-08-01

    The study describes the preparation and characterization of an environmentally friendly cement with performance characteristics similar to those of Portland cement, from a lime kiln bag house dust, a low-calcium fly ash, and a scrubber sludge. Promising preliminary results show the formation of relatively low-temperature phases calcium sulfoaluminate (4CaO{center{underscore}dot}3Al{sub 2}O{sub 3}{center{underscore}dot}SO{sub 3}) and dicalcium silicate (2CaO{center{underscore}dot}SiO{sub 2}) at {approximately} 1,250 C if nodulized raw means used for clinker preparation and at 1,175 C if powdered raw meal is used as compared to the {approximately} 1,500 C sintering temperature required for Portland cement. Phases of the developed cements were predicted using modified Bogue calculations. Isothermal calorimetric measurements indicate the hydration properties of the cements are comparable to ordinary Portland cement. Mechanical properties and microstructural evaluations also were carried out.

  11. Characteristics of dioxin emissions from a Waelz plant with acid and basic kiln mode.

    Hung, Pao Chen; Chi, Kai Hsien; Chen, Mei Lien; Chang, Moo Been

    2012-01-30

    The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in the flue gas of a Waelz plant operated in acid and basic modes, respectively. To abate (PCDD/F) and other pollutants, the plant operates with a post-treatment of flue gases by activated carbon injection and subsequent filtration. Relatively high PCDD/F discharge by fly ashes is found with acid kiln mode of the Waelz process. Therefore, basic kiln mode of the Waelz process is investigated and compared in this plant. With the adsorbent injection rate of 7 kg/h (95 mg/Nm(3)), the PCDD/F concentration in stack gas was measured as 0.123 ng I-TEQ/Nm(3) in the basic operating mode. The added Ca(OH)(2) reacted with metal catalysts and HCl((g)) in the flue gas and thus effectively suppressed the formation of PCDD/Fs. PCDD/F concentrations in fly ashes sampled from the dust settling chamber, cyclone, primary filter and secondary filter in basic kiln mode were significantly lower than that in acid kiln mode. Total PCDD/F emission on the basis of treating one kg of electric arc furnace dust in the basic operation mode was 269 ng I-TEQ/kg EAF-dust treated which was significantly lower than that in acid mode (640 ng I-TEQ/kg EAF-dust treated). Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Use of residual wood in the cement manufacturing process

    Gue, R.

    2005-01-01

    This PowerPoint presentation discussed the use of wood residuals in the cement manufacturing process. An outline of the cement manufacturing process was presented. Raw materials are combined in exact proportions to create a chemically correct mix, which is then pulverized in a mill. The mix is then burned in a kiln. The end product is cooled to form the pellet sized material known as clinker, which is then milled to form cement. The combustion and destruction characteristics of a cement kiln were presented. Modern cement kilns require approximately 3.2 Gj of energy to produce one tonne of cement. It was noted that wood residuals do not contain halogens, sulfur or other materials detrimental to the cement manufacturing process. Possible injection points for kilns were presented. Various studies have shown that wood residuals can be safely used as a fuel in the manufacture of cement. Environmental benefits derived from using wood included the complete destruction of organic portions, and the fact that residual ash becomes an indistinguishable part of the final product. It was concluded that wood residual materials are a satisfactory alternative fuel for the cement industry. tabs., figs

  13. Research of fluidized bed cement clinker sintering system by pilot plant; Ryudosho cement shosei gijutsu no kaihatsu. 7

    Sugiyama, T [Center for Coal Utilization, Japan, Tokyo (Japan); Sato, N; Hashimoto, I; Nakatsuka, M [The Cement Association of Japan, Tokyo (Japan)

    1996-09-01

    While a cement manufacturing process generally performs sintering by using a rotary kiln, a development work has been carried out as a subsidy operation of the Agency of Natural Resources and Energy on a cement sintering technology using a fluidized bed consisted of two furnaces: a jet flow bed granulating furnace and a fluidized bed sintering furnace. This paper reports the results of tests and researches performed during fiscal 1995. A plant with a scale of 20 ton-a-day production started in 1993 after having gone through bench scale tests. The year 1995 conducted by August its performance evaluation, review of the operation method and the safety criteria, and generalization of the tests. A multi-stage cyclone system has been employed in the preheating equipment for cement material powder. A number of improvements have been realized in the aspects of construction and operation, such as stabilization of dust collecting efficiency by employing a high-efficiency type cyclone, and operation with reduced pressure variation. Based on these results, a construction had been progressed in parallel on a new plant upscaled to 200 ton-a-day production. The new plant was completed in December, 1995. 9 figs., 8 tabs.

  14. Energy Efficiency Improvement Opportunities for the Cement Industry

    Price, Lynn; Worrell, Ernst; Galitsky, Christina; Price, Lynn

    2008-01-31

    This report provides information on the energy savings, costs, and carbon dioxide emissions reductions associated with implementation of a number of technologies and measures applicable to the cement industry. The technologies and measures include both state-of-the-art measures that are currently in use in cement enterprises worldwide as well as advanced measures that are either only in limited use or are near commercialization. This report focuses mainly on retrofit measures using commercially available technologies, but many of these technologies are applicable for new plants as well. Where possible, for each technology or measure, costs and energy savings per tonne of cement produced are estimated and then carbon dioxide emissions reductions are calculated based on the fuels used at the process step to which the technology or measure is applied. The analysis of cement kiln energy-efficiency opportunities is divided into technologies and measures that are applicable to the different stages of production and various kiln types used in China: raw materials (and fuel) preparation; clinker making (applicable to all kilns, rotary kilns only, vertical shaft kilns only); and finish grinding; as well as plant wide measures and product and feedstock changes that will reduce energy consumption for clinker making. Table 1 lists all measures in this report by process to which they apply, including plant wide measures and product or feedstock changes. Tables 2 through 8 provide the following information for each technology: fuel and electricity savings per tonne of cement; annual operating and capital costs per tonne of cement or estimated payback period; and, carbon dioxide emissions reductions for each measure applied to the production of cement. This information was originally collected for a report on the U.S. cement industry (Worrell and Galitsky, 2004) and a report on opportunities for China's cement kilns (Price and Galitsky, in press). The information provided in

  15. Application of ESP for gas cleaning in cement industry--with reference to India.

    Bapat, J D

    2001-02-16

    Electrostatic precipitators (ESP) are used for gas cleaning in almost every section of cement manufacture. Application of ESP is studied, keeping in view Indian conditions. The characterisation of dust emissions has been done for different units, such as rotary kiln and raw mill, alkali by-pass, clinker cooler, cement and coal mill, in terms of exit gas quantity, temperature, dew point, dust content and particle size. It is seen that all these characteristics have a wide range of variance. The ESP system must effectively deal with these variations. The fundamental analytical expression governing the performance of ESP, i.e. the Deutsch equation, and that for particle migration velocity, were analysed to predict the effect of major operating parameters, namely particle size, temperature and applied voltage. Whereas the migration velocity (and the efficiency) varies directly with the particle size, it is proportional to the square and square root of applied voltage and absolute temperature of the gas, respectively. The increase in efficiency due to temperature is not seen in dc based ESP, perhaps due to more pronounced negative effect on the applied voltage due to the increase in dust resistivity at higher temperatures. The effect of gas and dust characteristics on the collection efficiency of ESP, as seen in the industrial practice, is summarised. Some main process and design improvements effectively dealing with the problem of gas and dust characteristics have been discussed. These are gas conditioning, pulse energization, ESP-fabric filter (FF) combination, improved horizontal flow as well as open top ESP.Generally, gas conditioning entails higher operating and maintenance costs. Pulse energization allows the use of hot gas, besides reducing the dust emission and power consumption. The improved horizontal flow ESP has been successfully used in coal dust cleaning. The open top or vertical flow ESP has a limitation on collection efficiency as it provides for only

  16. Environmental Assessment of Different Cement Manufacturing ...

    Due to its high environmental impact and energy intensive production, the cement industry needs to adopt more energy efficient technologies to reduce its demand for fossil fuels and impact on the environment. Bearing in mind that cement is the most widely used material for housing and modern infrastructure, the aim of this paper is to analyse the Emergy and Ecological Footprint of different cement manufacturing processes for a particular cement plant. There are several mitigation measures that can be incorporated in the cement manufacturing process to reduce the demand for fossil fuels and consequently reduce the CO2 emissions. The mitigation measures considered in this paper were the use of alternative fuels and a more energy efficient kiln process. In order to estimate the sustainability effect of the aforementioned measures, Emergy and Ecological Footprint were calculated for four different scenarios. The results show that Emergy, due to the high input mass of raw material needed for clinker production, stays at about the same level. However, for the Ecological Footprint, the results show that by combining the use of alternative fuels together with a more energy efficient kiln process, the environmental impact of the cement manufacturing process can be lowered. The research paper presents an analysis of the sustainability of cement production , a major contributor to carbon emissions, with respect to using alternative fuels and a more efficient kiln. It show

  17. Secondary fuels and raw materials in the Spanish cement industry

    Gordobil, J.C.U.; Guede, Elena [Cementos Lemona s.a. (Spain)

    1997-03-01

    The growing environmental and energy concern are having an impact on the Spanish cement industry. This article describes the impact on waste management, the operation of cement kilns and the possibility for recycling. Current projects and future prospects are described. (UK)

  18. Sulfur Release from Cement Raw Materials during Solid Fuel Combustion

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

    2011-01-01

    During combustion of solid fuels in the material inlet end of cement rotary kilns, local reducing conditions can occur and cause decomposition of sulfates from cement raw materials. Decomposition of sulfates is problematic because it increases the gas-phase SO2 concentration, which may cause...... deposit formation in the kiln system. SO2 release from cement raw materials during combustion of solid fuels has been studied experimentally in a high temperature rotary drum. The fuels were tire rubber, pine wood, petcoke, sewage sludge, and polypropylene. The SO2 release from the raw materials...

  19. Timber drying kilns using solar energy

    NONE

    1995-12-15

    The objective of this project was to research the potential for solar kilns for drying timber in tropical countries (Guyana, Honduras and Belize) and produce a manual which will provide the knowledge necessary to build and operate a solar kiln. The main output of the project is the manual Solar Heated Timber Drying Kilns - a Manual on their Design and Operation. The manual covers:- background information; selection of construction materials; methods of kiln construction; kiln operation and maintenance procedure. The manual has been designed to provide the necessary knowledge and confidence to build and operate a solar kiln, and ultimately benefit from an improved product. Specifically, the manual will benefit small building construction units, furniture and joinery manufacturers and sawmill operators in developing and developed countries worldwide. (author)

  20. Geotechnical Properties of Clayey Soil Stabilized with Cement ...

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... ... to investigate the different effects of cement-sawdust ash and cement on a ... Keywords: Cement, Saw dust, strength test subgrade material, highway construction ... characteristics of lateritic soil stabilized with sawdust ash.

  1. Oxy-fuel combustion as an alternative for increasing lime production in rotary kilns

    Granados, D.A.; Chejne, F.; Mejía, J.M.

    2015-01-01

    Highlights: • A one-dimensional model for oxy-fuel combustion in a rotary kiln was developed. • Flue gas recirculation becomes an important parameter for controlling the process. • Combustion process decreases the flame length making it more dense. • Increases of 12% in raw material with 40% of FGR and conversion of 98% was obtained. - Abstract: The effect of Flue Gas Recirculation (FGR) on the decarbonation process during oxy-fuel combustion in a lime (and cement) rotary kiln is analyzed using an unsteady one-dimensional Eulerian–Lagrangian mathematical model. The model considers gas and limestone as continuous phases and the coal particles as the discrete phase. The model predicts limestone decarbonation, temperature and species distribution of gas and solid phases along the kiln. Simulation results of an air-combustion case are successfully validated with reported experimental data. This model is used to study and to compare the conventional air combustion process with oxy-fuel combustion with FGR ratios between 30% and 80% as controller parameter in this process. Changes in decarbonation process due to energy fluxes by convection and radiation with different FGRs were simulated and analyzed. Simulation results indicate a temperature increase of 20% in the gas and solid phases and a higher decarbonation rate of 40% in relation to the air-combustion case, for a given constant fuel consumption rate. However, for a given temperature, the increase of the CO_2 partial pressure in the oxy-fuel case promotes a reduction of the decarbonation rate. Therefore, there is a compromise between FGR and decarbonation rate, which is analyzed in the present study. Simulation results of the decarbonation step in low FGR cases, compared to air-combustion case, shows that conversion takes place in shorter distances in the kiln, suggesting that the production rate can be increased for existing kilns in oxy-fuel kilns or, equivalently, shorter kilns can be designed for an

  2. Dynamic Analysis of the Temperature and the Concentration Profiles of an Industrial Rotary Kiln Used in Clinker Production

    DIULIA C.Q. RODRIGUES

    Full Text Available ABSTRACT Cement is one of the most used building materials in the world. The process of cement production involves numerous and complex reactions that occur under different temperatures. Thus, there is great interest in the optimization of cement manufacturing. Clinker production is one of the main steps of cement production and it occurs inside the kiln. In this paper, the dry process of clinker production is analysed in a rotary kiln that operates in counter flow. The main phenomena involved in clinker production is as follows: free residual water evaporation of raw material, decomposition of magnesium carbonate, decarbonation, formation of C3A and C4AF, formation of dicalcium silicate, and formation of tricalcium silicate. The main objective of this study was to propose a mathematical model that realistically describes the temperature profile and the concentration of clinker components in a real rotary kiln. In addition, the influence of different speeds of inlet gas and solids in the system was analysed. The mathematical model is composed of partial differential equations. The model was implemented in Mathcad (available at CCA/UFES and solved using industrial input data. The proposal model is satisfactory to describe the temperature and concentration profiles of a real rotary kiln.

  3. Dynamic Analysis of the Temperature and the Concentration Profiles of an Industrial Rotary Kiln Used in Clinker Production.

    Rodrigues, Diulia C Q; Soares, Atílio P; Costa, Esly F; Costa, Andréa O S

    2017-01-01

    Cement is one of the most used building materials in the world. The process of cement production involves numerous and complex reactions that occur under different temperatures. Thus, there is great interest in the optimization of cement manufacturing. Clinker production is one of the main steps of cement production and it occurs inside the kiln. In this paper, the dry process of clinker production is analysed in a rotary kiln that operates in counter flow. The main phenomena involved in clinker production is as follows: free residual water evaporation of raw material, decomposition of magnesium carbonate, decarbonation, formation of C3A and C4AF, formation of dicalcium silicate, and formation of tricalcium silicate. The main objective of this study was to propose a mathematical model that realistically describes the temperature profile and the concentration of clinker components in a real rotary kiln. In addition, the influence of different speeds of inlet gas and solids in the system was analysed. The mathematical model is composed of partial differential equations. The model was implemented in Mathcad (available at CCA/UFES) and solved using industrial input data. The proposal model is satisfactory to describe the temperature and concentration profiles of a real rotary kiln.

  4. European cement conference and exhibition. Proceedings volume

    McCaffrey, R. (ed.)

    2004-07-01

    Topics covered various aspects of the European cement industry including trends, market, emissions trading, environment, state-of-the-art technology, kilns and dedusting solutions. Two papers have been abstracted separately. A CD-ROM of the conference papers, including additional papers not in the printed volume, is also available.

  5. Energetic and exergetic analysis of waste heat recovery systems in the cement industry

    Karellas, S.; Leontaritis, A.-D.; Panousis, G.; Bellos, E.; Kakaras, E.

    2013-01-01

    In a typical cement producing procedure, 25% of the total energy used is electricity and 75% is thermal energy. However, the process is characterized by significant heat losses mainly by the flue gases and the ambient air stream used for cooling down the clinker (about 35%–40% of the process heat loss). Approximately 26% of the heat input to the system is lost due to dust, clinker discharge, radiation and convection losses from the kiln and the preheaters. A heat recovery system could be used to increase the efficiency of the cement plant and thus contribute to emissions decrease. The aim of this paper is to examine and compare energetically and exergetically, two different WHR (waste heat recovery) methods: a water-steam Rankine cycle, and an Organic Rankine Cycle (ORC). A parametric study proved that the water steam technology is more efficient than ORC in exhaust gases temperature higher than 310 °C. Finally a brief economic assessment of the most efficient solution was implemented. WHR installations in cement industry can contribute significantly in the reduction of the electrical consumptions operating cost thus being a very attractive investment with a payback period up to 5 years. - Highlights: • This paper presents waste heat recovery as a way to gain energy from the exhaust gases in a cement plant. • Water steam cycle and ORC has been analyzed for waste heat recovery. • The energetic and exergetic evaluation of the two waste heat recovery processes is presented and compared

  6. Biomass for green cement

    Cumming, R. [Lafarge Canada Inc., Calgary, AB (Canada)

    2006-07-01

    Lafarge examined the use of waste biomass products in its building materials and provided background information on its operations. Cement kiln infrastructure was described in terms of providing access to shipping, rail and highways; conveying and off-loading equipment; having large storage facilities; and, offering continuous monitoring and stack testing. The presentation identified the advantages and disadvantages of a few different biomass cases such as coal; scrap tires; non-recyclable household waste; and processed biomass. A chart representing landfill diversion rates was presented and the presentation concluded with a discussion of energy recovery and recycling. 1 tab., figs.

  7. Production of brown coal fuel dust as a high value and effective energy carrier for substituting heating oil, natural gas and black coal in the cement and metallurgical industry

    Kubasch, A.

    1985-01-01

    Poduction and industrial use of brown coal dust in the German Democratic Republic are reviewed. Dust production in 14 brown coal briquetting plants increased from 818.4 kt in 1980 to 2064 kt in 1984 and will exceed 4000 kt in 1990. Quality parameters of dusts according to the TGL 15380 industrial standard are listed. The railroad car loading and shipping technology is explained with the example of modern facilities of the Schwarze Pumpe briquetting plant: dust bunkers of 200 t storage capacity, pneumatic feeding and telescope discharge systems with nitrogen gas inertization, fire prevention, and railroad car cleaning equipment, rail track heating for improved winter loading conditions, etc. Since 1979 the Deuna, Karsdorf and Bernburg cement plants have been converted to brown coal dust combustion after installation of new fuel dust shipping, storage and combustion equipment. Substitution of heating oil and gas in metallurgical blast furnaces by brown coal dust is further described. Techogical advantages of the pneumatic KOSTE fuel feeding method are enumerated.

  8. Turbulent diffusion in the flame of a rotary kiln

    Strekotin, V.V.; Telegin, A.A.; Lisin, F.N.; Malysheva, O.I.

    1987-09-01

    Experimental data on the distribution of velocities in the stream in the flow of air from models of a burner with a normal annular Laval nozzle and a burner with an increase in the angle of opening of the stream under supersonic conditions were obtained. The results of the work may be used in the design of burners for rotary kilns. According to the experimental data the coefficient of turbulent diffusion reaches a value of 0.0071 m/sup 2//sec for a pure flow and is reduced by 30% with an increase in the dust content from 0 to 1 kg/kg. It is desirable to use the data obtained in calculations of the flame processes and selection of means of intensification of the process of mixing of the fuel with the oxidizer in the presence of dust.

  9. Optimising a fall out dust monitoring sampling programme at a ...

    GREG

    Key words: Fall out dust monitoring, cement plant, optimising, air pollution sampling, fall out dust sampler locations. .... applied for those areas where controls are in place. Sampling ..... mass balance in the total cement manufacturing process.

  10. Trabalho e saúde: a atividade da queima de resíduos tóxicos em fornos de cimenteiras de Cantagalo, Rio de Janeiro Work and health: the activity of burning toxic waste in cement kilns in Cantagalo, Rio de Janeiro State

    Afrânio Gomes Pinto Júnior

    2009-12-01

    Full Text Available Este estudo ocupa-se de analisar as condições de trabalho e saúde a partir dos relatos dos trabalhadores envolvidos na atividade de coprocessamento de resíduos tóxicos em fornos de cimenteiras de Cantagalo (RJ. Realizamos uma investigação qualitativa baseada na utilização de roteiro semi-estruturado, na qual foram entrevistados treze indivíduos. Na análise do discurso, foi possível observar falhas no planejamento do processo de trabalho, na identificação de riscos, na prevenção de agravos, no monitoramento de impactos à saúde e ao ambiente, bem como na identificação e notificação aos órgãos competentes. A assimilação das incertezas do processo, favorecendo os interesses dos empreendedores, permitiu que recaísse sobre os trabalhadores o ônus do adoecimento, aceitável na medida em que se negam evidências clínicas. Torna-se imperioso amplo debate que envolva entes públicos e privados, a sociedade e suas representações, confrontando-se questões éticas, ambientais e de saúde aos interesses do capital, para que se estabeleçam novas diretrizes para o processo.This study analyzes the work and health conditions through the discourse of the employees involved in the activity of toxic waste co-processing in cement kilns in Cantagalo, RJ. A qualitative approach was adopted using a semi-structured interview with 13 individuals. After analyzing the discourse, it was possible to observe relevant failures in the work process planning, in the identification of risks, in preventing diseases, in monitoring health impacts and to the environment, even their identification and notification to the competent authorities. The assimilation of the uncertainties of the process, favoring the interests of the entrepreneurs, has passed on the workers the burden of illness, rendered acceptable in that they deny clinical evidences. It is imperative to establish a broad debate involving public and private entities, the society in all its

  11. PHYSICAL AND STRENGTH PROPERTIES OF BRICKS PRODUCED FROM PORTLAND CEMENT AND SAW DUST OF DANIELIA OLIVERII WOOD

    David Oriabure EKHUEMELO

    2016-12-01

    Full Text Available This study investigated the use of sawdust as partial replacement for sand in wood-concrete hollow blocks. Sharp sand, ordinary Portland cement (binder and sawdust were used as raw materials. Sawdust was treated by boiling then sieved after drying using British Standard sieve of 3.35mm to remove sticky wood capable of causing pores. The quantities of sawdust used were 0%, 5%, 10%, 15% and 20%. A mixing proportion of 1:8 cement sand ratio, moulding machine with single 6” (450mm x 225mm x 150mm mould and vibrated with 5.0KW power machine for adequate compaction were used. Wood-concrete block was cured for 28 days. The blocks produced were tested for compressive strength and water absorption. The results showed that mean compressive strength of 100% sand was 2.81N/mm2 followed by 95% sand and 5% sawdust replacement with 1.58N/mm2 ; 90% Sand and 10% sawdust replacement with 0.55N/mm2 ; 85% sand and 15% sawdust replacement with 0.43 N/mm2 and 80% sand 20% sawdust replacement with 0.24N/mm2 . The result further showed that as the percentage of sawdust increased, the compressive strength decreased. At 28 days, the compressive strength of blocks with 5% SD replacement satisfied meets Ghana Building Code for non- load bearing walls. The results also reveals that blocks with 80% sand 20% sawdust replacement level has the highest water absorption (23.72% followed by 85% Sand and 15% sawdust replacement (20.40%; 90% sand and 10% sawdust replacement (18.0%; 95% sand and 5% sawdust replacement (12.12% and 100% sand and 0% sawdust replacement (11.43%. It was concluded that 5% sawdust (8kg replacement and cured 28 days could be used for non-load bearing walls. It was recommended that further research should be carried out to evaluate sawdust replacement level within the range of 1-4% to ascertain results that could be used for various other purposes.

  12. Physical and Strength Properties of Bricks Produced from Portland Cement and Saw Dust of Danielia Oliverii Wood

    David Oriabure EKHUEMELO

    2016-12-01

    Full Text Available This study investigated the use of sawdust as partial replacement for sand in wood-concrete hollow blocks. Sharp sand, ordinary Portland cement (binder and sawdust were used as raw materials. Sawdust was treated by boiling then sieved after drying using British Standard sieve of 3.35mm to remove sticky wood capable of causing pores. The quantities of sawdust used were 0%, 5%, 10%, 15% and 20%. A mixing proportion of 1:8 cement sand ratio, moulding machine with single 6” (450mm x 225mm x 150mm mould and vibrated with 5.0KW power machine for adequate compaction were used. Wood-concrete block was cured for 28 days. The blocks produced were tested for compressive strength and water absorption. The results showed that mean compressive strength of 100% sand was 2.81N/mm2 followed by 95% sand and 5% sawdust replacement with 1.58N/mm2 ; 90% Sand and 10% sawdust replacement with 0.55N/mm2 ; 85% sand and 15% sawdust replacement with 0.43 N/mm2 and 80% sand 20% sawdust replacement with 0.24N/mm2 . The result further showed that as the percentage of sawdust increased, the compressive strength decreased. At 28 days, the compressive strength of blocks with 5% SD replacement satisfied meets Ghana Building Code for non- load bearing walls. The results also reveals that blocks with 80% sand 20% sawdust replacement level has the highest water absorption (23.72% followed by 85% Sand and 15% sawdust replacement (20.40%; 90% sand and 10% sawdust replacement (18.0%; 95% sand and 5% sawdust replacement (12.12% and 100% sand and 0% sawdust replacement (11.43%. It was concluded that 5% sawdust (8kg replacement and cured 28 days could be used for non-load bearing walls. It was recommended that further research should be carried out to evaluate sawdust replacement level within the range of 1-4% to ascertain results that could be used for various other purposes.

  13. Assessing the Effect of Cement Dust Emission on the Physicochemical Nature of Soil around Messebo area, Tigray, North Ethopia

    SAMUEL ESTIFANOS

    2012-12-01

    Full Text Available Twenty six soil samples were collected around the vicinity of Messebo cement factory in Mekelle, Ethiopia from 0-5 and 5-15 cm depths and determined their physicochemical properties and heavy metals contents. The results indicated that the soils are calcareous having sandy loam to loamy sand texture. The top and lower parts of the soil are found to be alkaline with mean pH 8.97 and 8.93; EC 223.06 and 88.22 µS/cm respectively. The cation exchange capacity of the top soil (0-5cm range from 9 to 27 mmolc kg-1, while the exchangeable Ca and Mg range from 6.4 to 16 and 2.2 to 5.0 mmolc kg- 1 respectively. The average Ca concentration values for the upper and lower soil depths are 418ppm and 404.36ppm respectively. Water extractable analysis results verify the degree of leaching of the metals from anthropogenic source. Geoaccumulation index confirms that the two soil depths are similarly categorized as very heavily contaminated with (As, Cr, Co and Ni and moderately to heavily contaminated with (Cu, Pb and Mo whereas the top part is moderately contaminated with Zn. Based on Enrichment Factor (EF, both soil depths have moderate enrichment with Pb ( 2 EF >20, very high enrichment with Cr (2040. The severe contamination is evident to the east western direction towards which the wind blow predominantly.

  14. EDXRF analysis of Yanhedian Ru kiln and Jun official kiln porcelain

    Wen Chang; Zhao Huixian; Li Guoxia; Gao Zhengyao; Zhao Weijuan; Sun Hongwei; Guo Min; Xie Jianzhong; Li Rongwu; Guo Peiyu

    2009-01-01

    The chemical components of the body and glaze samples of some Ru porcelains from Yanhedian kiln and Jun official porcelains from Juntai kiln are determined by the technology of Energy Dispersive X-ray Fluorescence(EDXRF) in this work. The difference of the two kiln's glaze and body are analyzed by factor analysis method of Multi-dimensional statistical analysis. The results indicate that Yanhedian Ru porcelains can be well distinguished from Jun official porcelains from Juntai kiln. This evidence once again proves that Jun ceramics and Ru ceramics can be distinguished obviously. (authors)

  15. Emission during the firing of chrome-magnesite products in tunnel kilns

    Krechin, Yu.V.; Telegin, S.V.; Ivanov, N.M.; Kasimov, A.M.; Plichko, E.P.; Sverkov, Yu.M.; Maksimov, B.N.

    1986-11-01

    When chrome-magnesite products are fired in tunnel furnaces, the concentration in the effluent gas of dust is 110-150; of Cr/sub 7/O/sub 3/, 5-7; NO/sub x/, 20-35; CO, 100-125; SO/sub 2/, 25-40; and SO/sub 3/, 30-70 mg/m/sup 3/. The emission dust is finely dispersed. The average size of the particles of dust is 0.3, the minimum 0.05, and the maximum 1 ..mu..m. There is no hydrogen sulfide, NO/sub 2/, or CrO/sub 3/ in the emission. Dust and nitrogen oxides are formed in the firing zone of the kiln. The formation of dust and NO/sub 2/ depends on the air-consumption coefficient. The use of the pipe-in-pipe type of ports does not provide good gas combustion. To improve the operation of the kiln and the combustion of the natural gas it is recommended that instead of the obsolescent tube-in-tube ports, the ports developed by the Eastern Institute of Refractories be installed since they have given good results in tests. To improve the scattering effect of the removal of dust in the existing equipment it is recommended that the height of the flue stacks be increased to 40-50 m.

  16. Fabrication works on rotary kiln fluidized bed

    Shahazrin Mohd Nasir; Mohamad Azman Che Mat Isa; Mohamad Puad Haji Abu; Mohd Fairus Abdul Farid

    2005-01-01

    Rotary kiln has been widely used in incineration and studied by many researches. Solid wastes of various shapes, sizes and heat value can be fed into rotary kiln either in batches or continually. Waste combustion in rotary kiln involves rotation method and the residence time depends on the length and diameter of the rotary kiln and the total stichomythic air given to the system.Rocking system is another technology used in incinerator. In the rocking system, internal elements in the combustion chamber move to transports and mix the burning waste so that all combustible material in the waste is fully burnt. Another technology in incinerator is the fluidized bed. This method uses air to fluidized the sand thus enhancing the combustion process. The total air is controlled in order to obtain a suitable fluidized condition.This preliminary study was conducted to study the feasibility of an incinerator system when three components viz. the rotary kiln, rocking system and fluidized bed are combined. This research was also conducted to obtain preliminary data parameters of the three components such as the suitable temperature, the angle of the kiln, residence time, total air for fluidization, rocking speed and the devolatilization rate. The samples used in this research were the palm oil kernel shells. (Author)

  17. Low-alkali cement from high-efficiency kilns?

    Clausen, C. F.

    1960-06-01

    Full Text Available Not availableHace unos veinte años, la industria del cemento mantiene una vigilancia extrema del efecto, a veces pernicioso, de los álcalis en el hormigón, esta industria reconoce, por otro lado, la necesidad de fabricar cementos bajos en álcalis, cuando se han de emplear para determinados usos.

  18. Utilization of lime-dried sludge for eco-cement clinker production: effects of different feeding points.

    Cao, Haihua; Liu, Wei; Xu, Jingcheng; Liu, Jia; Huang, Juwen; Huang, Xiangfeng; Li, Guangming

    2018-02-01

    Co-processing lime-dried sludge (LDS) in cement kilns is an appropriate technique to solve the problem of LDS disposal and promote the sustainable development for cement industry. However, there were limited studies that investigated the effects of feeding points on product quality and cement kiln emissions. In this study, simulated experiments were conducted by dividing the feeding points into high-temperature zones (HTZs) and raw mill (RM). Cement quality and major cement kiln emission characteristics were comprehensively investigated. The results showed that in terms of burnability, compressive strength and microstructure, the optimum co-processing amount of LDS were 9 wt% when feeding at RM, while 6% when feeding at HTZs. Meanwhile, the organic emissions of RM samples were mainly low environmental risk compounds of amides and nitrogenous heterocyclic compounds. Inorganic gaseous pollutions of NO X and SO 2 , respectively, were 8.11 mg/g DS and 12.89 mg/g DS, compared with 7.61 mg/g DS and 4.44 mg/g DS for HTZs. However, all the cement kiln emissions concentration were still much lower than standard requirements. Overall, RM had a bigger LDS co-processing capacity and higher, but acceptable, cement kiln emissions. Feeding LDS via RM could dispose larger amounts of sludge and provide more alternative materials for cement manufacturing.

  19. Mixing large and small particles in a pilot scale rotary kiln

    Nielsen, Anders Rooma; Aniol, Rasmus Wochnik; Larsen, Morten Boberg

    2011-01-01

    The mixing of solid alternative fuel particles in cement raw materials was studied experimentally by visual observation in a pilot scale rotary kiln. Fuel particles were placed on top of the raw material bed prior to the experiment. The percentage of particles visible above the bed as a function...... of time was evaluated with the bed predominantly in the rolling bed mode. Experiments were conducted to investigate the effects of fuel particle size and shape, fuel particle density, rotary kiln fill degree and rotational speed. Large fuel particles and low-density fuel particles appeared more on top...... of the bed than smaller particles and high-density fuel particles. Fuel particle dimensions and sphericity were important parameters for the percentage of visible particles. Increasing bed fill degree and/or increasing rotational speed decreased the percentage of particles visible on top of the bed...

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

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

    2011-01-01

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

  1. Dissolution of heavy metals from electrostatic precipitator (ESP) dust ...

    Coal based sponge iron industries in India generate considerable quantity of solid waste, 40% of which is flue dust produced from the electrostatic precipitator (ESP) connected to rotary kiln. This paper reports the dissolution of Zn, Cu, Pb, Mn and Fe from the ESP dust using three fungal species, Aspergillus niger, ...

  2. 27 CFR 9.27 - Lime Kiln Valley.

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lime Kiln Valley. 9.27... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.27 Lime Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley...

  3. Integration of oxygen membranes for oxygen production in cement plants

    Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus

    2015-01-01

    The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...

  4. Report for fiscal 1999 on the fundamental survey on promotion of joint implementation. Modernization of Bakabad Cement Factory; 1999 nendo kyodo jisshi nado suishin kiso chosa Bekbad cement kojo kindaika chosa hokokusho

    NONE

    2000-03-01

    This paper describes the result in fiscal 1999 of the feasibility study applied with the COP3 clean development mechanism for Bekabad Cement Factory in the Republic of Uzbekistan. One of the existing three old type kilns were diverted and converted into a dry NSP type kiln (having the same production capacity as the present of 726,000 tons a year). This arrangement was intended to enhance the productivity, save the energy, and reduce emission of greenhouse gases and different pollutants by renewing the upper and lower stream facilities and installing such environmental devices as electric dust collectors and bag filters. The total construction cost is US$84,432,000. Reducible energy consumption and reduction quantity of greenhouse gases would be 73,232 toe/year and 176,528 toe/year, respectively, in the single fiscal 2006. The cumulative quantity over twenty-year period until 2025 would be 1,464,640 toe and 3,530,560 toe, respectively. The energy saving effect per US$1,000 would be 17.87 toe, and the greenhouse gas reduction effect would be 43.08 t. In the case of using a soft loan such as the special yen loan for environment application, the internal profit rate after tax would be 7.63%, which is not high as the business enterprise profitability. However, the profit and loss statement indicates creation of profit after two years of operation, hence there is a relative realization possibility. (NEDO)

  5. Report of year 2000 version on basic survey for promotion of joint execution. Modernization of Bekabad Cement Plant

    NONE

    2000-03-01

    This paper describes the result of applying the COP3 clean development mechanism to Bekabad Cement Plant in Uzbekistan. One of the three existing outdated wet process kilns will be converted into a new NSP kiln (having the same production capacity as now of 726,000 tons/year). Upstream and downstream facilities will be renewed, and environmental devices such as electric dust collectors and bag filters will be installed to enhance the productivity, conserve the energies, and reduce production of greenhouse effect gases and different pollutants. The total construction cost will be US$84,432,000. Reducible energy consumption and reduction in the greenhouse effect gases will be 73,232 toe/year and 176,528 toe/year respectively in a single fiscal year of 2006, and cumulative total amount in 20 years until 2025 will be 1,464,640 toe and 3,530,560 t. The energy saving effect per US$1,000 will be 17.87 toe, and the greenhouse gas reduction effect will be 43.08 t. In case of using such a soft loan as the special Yen loan for environment, the internal profit rate after tax will be 7.63%, which is not necessarily high as the business profitability. However, the profit and loss calculation sheet indicates that profit will be produced in two years after the inauguration of the operation, which is promised as relatively high possibility of realization. (NEDO)

  6. Design Robust Controller for Rotary Kiln

    Omar D. Hernández-Arboleda

    2013-11-01

    Full Text Available This paper presents the design of a robust controller for a rotary kiln. The designed controller is a combination of a fractional PID and linear quadratic regulator (LQR, these are not used to control the kiln until now, in addition robustness criteria are evaluated (gain margin, phase margin, strength gain, rejecting high frequency noise and sensitivity applied to the entire model (controller-plant, obtaining good results with a frequency range of 0.020 to 90 rad/s, which contributes to the robustness of the system.

  7. 40 CFR 63.1344 - Operating limits for kilns and in-line kiln/raw mills.

    2010-07-01

    ... kiln/raw mills. 63.1344 Section 63.1344 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... mills. (a) The owner or operator of a kiln subject to a D/F emission limitation under § 63.1343 must... specified in paragraph (b) of this section. The owner or operator of an in-line kiln/raw mill subject to a D...

  8. Mercury regulation, fate, transport, transformation, and abatement within cement manufacturing facilities: review.

    Sikkema, Joel K; Alleman, James E; Ong, Say Kee; Wheelock, Thomas D

    2011-09-15

    The USEPA's 2010 mercury rule, which would reduce emissions from non-hazardous waste burning cement manufacturing facilities by an estimated 94%, represents a substantial regulatory challenge for the industry. These regulations, based on the performance of facilities that benefit from low concentrations of mercury in their feedstock and fuel inputs (e.g., limestone concentration was less than 25 ppb at each facility), will require non-compliant facilities to develop innovative controls. Control development is difficult because each facility's emissions must be assessed and simple correlation to mercury concentrations in limestone or an assumption of 'typically observed' mercury concentrations in inputs are unsupported by available data. Furthermore, atmospheric emissions are highly variable due to an internal control mechanism that captures and loops mercury between the high-temperature kiln and low-temperature raw materials mill. Two models have been reported to predict emissions; however, they have not been benchmarked against data from the internal components that capture mercury and do not distinguish between mercury species, which have different sorption and desorption properties. Control strategies include technologies applied from other industries and technologies developed specifically for cement facilities. Reported technologies, listed from highest to lowest anticipated mercury removal, include purge of collected dust or raw meal, changes in feedstocks and fuels, wet scrubbing, cleaning of mercury enriched dust, dry sorbent injection, and dry and semi-dry scrubbing. The effectiveness of these technologies is limited by an inadequate understanding of sorption, desorption, and mercury species involved in internal loop mercury control. To comply with the mercury rule and to improve current mercury control technologies and practices, research is needed to advance fundamental knowledge regarding mercury species sorption and desorption dynamics on materials

  9. Lime Kiln Dust for Treated Subgrades : Final Report

    2017-11-01

    Chemical and cementitious materials are often used to modify and stabilize the subgrade soils that serve as foundations for pavements. Improvement of the subgrade provides a better working platform for construction of the layers above and improves th...

  10. Lime Kiln Dust for Treated Subgrades : Technical Summary

    2017-11-01

    Chemical and cementitious materials are often used to modify and stabilize the subgrade soils that serve as foundations for pavements. Improvement of the subgrade provides a better working platform for construction of the layers above and improves th...

  11. Analysis of Energy-Efficiency Opportunities for the Cement Industry in Shandong Province, China

    Price, Lynn; Hasanbeigi, Ali; Lu, Hongyou; Wang, Lan

    2009-10-01

    China's cement industry, which produced 1,388 million metric tons (Mt) of cement in 2008, accounts for almost half of the world's total cement production. Nearly 40% of China's cement production is from relatively obsolete vertical shaft kiln (VSK) cement plants, with the remainder from more modern rotary kiln cement plants, including plants equipped with new suspension pre-heater and pre-calciner (NSP) kilns. Shandong Province is the largest cement-producing Province in China, producing 10% of China's total cement output in 2008. This report documents an analysis of the potential to improve the energy efficiency of NSP kiln cement plants in Shandong Province. Sixteen NSP kiln cement plants were surveyed regarding their cement production, energy consumption, and current adoption of 34 energy-efficient technologies and measures. Plant energy use was compared to both domestic (Chinese) and international best practice using the Benchmarking and Energy Saving Tool for Cement (BEST-Cement). This benchmarking exercise indicated an average technical potential primary energy savings of 12% would be possible if the surveyed plants operated at domestic best practice levels in terms of energy use per ton of cement produced. Average technical potential primary energy savings of 23% would be realized if the plants operated at international best practice levels. Energy conservation supply curves for both fuel and electricity savings were then constructed for the 16 surveyed plants. Using the bottom-up electricity conservation supply curve model, the cost-effective electricity efficiency potential for the studied cement plants in 2008 is estimated to be 373 gigawatt hours (GWh), which accounts for 16% of total electricity use in the 16 surveyed cement plants in 2008. Total technical electricity-saving potential is 915 GWh, which accounts for 40% of total electricity use in the studied plants in 2008. The fuel conservation supply curve model shows the total

  12. Cermet cements.

    McLean, J W

    1990-01-01

    Cermet ionomer cements are sintered metal/glass powders, which can be made to react with poly(acids). These new cements are significantly more resistant to abrasion than regular glass ionomer cements and are widely accepted as core build-up materials and lining cements. They can strengthen teeth and provide the clinician with an opportunity to treat early dental caries.

  13. Coal dust symposium

    1981-03-01

    This paper gives a report of the paper presented at the symposium held in Hanover on 9 and 10 February 1981. The topics include: the behaviour of dust and coal dust on combustion and explosion; a report on the accidents which occurred at the Laegerdorf cement works' coal crushing and drying plant; current safety requirements at coal crushing and drying plant; and coal crushing and drying. Four papers are individually abstracted. (In German)

  14. Wood fuel use in Tanzania rural-based industries. Brick kiln studies in Tanzania

    Kiwele, P.M.; Mbise, H.A.; Mwihava, N.C.X.; Svenningsson, P.J.

    1999-07-01

    years ago indicate that SEC figures for Zimbabwe vary from 1.93 to 2.71 MJ/kg. Data from other sources indicate figures in the range of 3.8 to 7.5 MJ/kg. With regard to the trial runs made using saw dust and coal, the SEC figures were in the range of 1.4 to 2.5 MJ/kg, which are comparable to those found when wood fuel alone is utilised. Generally, a high SEC could be a reflection of well-burnt bricks, while low SEC could imply poorly burnt bricks. It may therefore be difficult to compare SEC for different kilns unless the quality of the product is pre-determined. It should be noted that the observed results do not necessarily undermine the potential for future utilisation of alternative fuels like sawdust and coal dust. In this study the main areas of energy losses were found to be related to: inappropriate kiln configuration and volume; quality of fuel used; inadequate management of the firing process; poor control of the leakage points; over-firing and inappropriate size of bricks. The main recommendations in this study include: the need to conduct an environmental impact assessment of the brick-making activity; the need to establish local standards to ensure reliability; the need to use alternative fuels such as Euphorbia tiruculi and Eucalyptus since they grow faster and therefore reducing pressure on the natural forests; and preparation of operating manuals in both Swahili and English languages.

  15. Surplus biomass through energy efficient kilns

    Anderson, Jan-Olof; Westerlund, Lars

    2011-01-01

    Highlights: → The magnitude of the national heat demand for drying lumber in kilns is established. → Each part of the total heat consumption is divided and shown between the main drying conditions. → The potential to increase the energy efficiency in kilns with available techniques is presented. → The market demand for the biomass, available with increase kiln energy efficiency, is reviled. -- Abstract: The use of biomass in the European Union has increased since the middle of the 1990s, mostly because of high subsidies and CO 2 emission regulation through the Kyoto protocol. The sawmills are huge biomass suppliers to the market; out of the Swedish annual lumber production of 16.4 Mm 3 , 95% is produced by medium to large-volume sawmills with a lumber quotient of 47%. The remaining part is produced as biomass. An essential part (12%) of the entering timber is used for supply of heat in their production processes, mostly in the substantial drying process. The drying process is the most time and heat consuming process in the sawmill. This study was undertaken to determine the sawmills' national use of energy and potential magnitude of improvements. If the drying process can be made more effective, sawmills' own use of biomass can be decreased and allow a considerably larger supply to the biomass market through processed or unprocessed biomass, heat or electricity production. The national electricity and heat usage when drying the lumber have been analysed by theoretical evaluation and experimental validation at a batch kiln. The main conclusion is that the heat consumption for drying lumber among the Swedish sawmills is 4.9 TW h/year, and with available state-of-the-art techniques it is possible to decrease the national heat consumption by approximately 2.9 TW h. This additional amount of energy corresponds to the market's desire for larger energy supply.

  16. Digital Kilns and Furnaces——the Development Direction of Industrial Kilns and Furnaces in the 21st Century

    WANG Xiaoming; HUANG Zhichu; ZHANG Jiafan

    2006-01-01

    The digital manufacturing theory is applied to the special manufacturing equipments--industrial kilns and furnaces; the concept of digital kilns & furnaces is put forward. The present status of research and application for digital technologies in fuel industrial kilns & furnaces is also introduced. Then, take the case of gas fuel kilns & furnaces, their main key technical issues are discussed. Digital kilns & furnaces as an important constituent of the digital equipments are the crucial base of the digital manufacturing. The value of research on digital kilns & furnaces and the application prospect are undoubted. It will improve product quality, reduce the manpower cost, enhance product market competitive ability, promote comprehensively tradition industries such as ceramics, metallurgy industry,and so on.

  17. Use of petroleum code as fuel in the cement industry

    Nawaz, S.

    2006-01-01

    The Cement industry is a very energy intensive industry. Each ton of cement produced requires 60 to 130 kilograms of fuel oil or an equivalent fuelling amount also requires an average 110 kWh of electricity as well over 40% of total production cost is the energy requirements in the cement industry (i.2). Normally oil, gas or coal is fired in cement kilns as traditional fuels. However use of waste, both as alternative fuels and raw materials is now common practice in many cement companies. Many different types of wastes are burnt today in cement kilns like used tyres, rubber, paper waste, waste oils, waste wood, paper sludge, sewage, animal meal and animal remains (i,4). The choice of fuel for the purpose is normally based on price and availability considering different properties of the fuel as energy contents, ash contents, moisture and volatiles contents. Petcoke is not yet produced in any petroleum refinery in Pakistan but it is abundantly available in the market worldwide as it is obtained as a waste product during the refining processes. The purpose of the current research is to figure out the suitability of petroleum coke as a fuel for cement industry both on technical and economic basis. (author)

  18. Ventilatory Function and Cigarette Smoking in Cement Handlers in ...

    Introduction: Occupational exposure to dust and cigarette smoking play important roles in the pathogenesis of lung diseases, particularly in developing countries. To determine the effects of outdoor cement dust exposure and cigarette smoking on lung health, we compared ventilatory function in cement handlers (smokers ...

  19. Technical benefit and risk analysis on cement clinkering process with compact internal burning of carbon

    Chen, Hanmin

    2015-01-01

    This article demonstrates the potential technical benefit and risk for cement clinkering process with compact internal burning of carbon, a laboratory-phase developing technique, from 9 aspects, including the heat consumption of clinkering and exhaust heat utilization, clinker quality, adaptability to alternative fuels, the disposal ability of industrial offal and civil garbage, adaptability to the raw materials and fuels with high content of chlorine, sulphur and alkali, the feasibility of process scale up, the briquetting process of the coal-containing cement raw meal pellet, NO x emission and the capital cost and benefit of conversion project. It is concluded that it will be able to replace the modern precalciner rotary kiln process and to become the main stream technique of cement clinkering process in low carbon economy times. - Highlights: • Compact internal burning of carbon enables cement shaft kiln to run stably. • Compact internal burning of carbon enables cement shaft kiln to scale up. • New process triples energy efficiency with excellent environmental performance. • It will be able to compete with and replace the existing precalciner kiln process. • It will become the mainstream clinkering process in low carbon economy

  20. Pollutants emitted by a cement plant: health risks for the population living in the neighborhood

    Schuhmacher, Marta; Domingo, J.L.; Garreta, Josepa

    2004-01-01

    The aim of this study was to investigate the health risks due to combustor emissions in the manufacturing of Portland cement for the population living in the neighborhood of a cement kiln in Catalonia, Spain. Pollutants emitted to the atmosphere in the course of cement production were modeled. The ISC3-ST model was applied to estimate air dispersion of the contaminants emitted by the cement plant. Air concentrations of NO 2 , SO 2 , PM 10 , metals, and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), as well as the potential exposure in the vicinity of the facility, were assessed via models based on US EPA guidance documents. PCDD/F and metal concentrations were also modeled for soil and vegetation. Based on these concentrations, the levels of human exposure were calculated. Individual cancer and noncancer risks for the emissions of the cement kiln were assessed. Health effects due to NO 2 , SO 2 , and PM 10 emissions were also evaluated. Risk assessment was performed as a deterministic analysis. The main individual risk in the population was evaluated in a central-tendency and a high-end approach. The results show that the incremental individual risk due to emissions of the cement plant is very low not only with regard to health effects, but also in relation to toxicological and cancer risks produced by pollutants such as metals and PCDD/Fs emitted by the cement kiln

  1. Thermal behavior of kiln cars while traveling through a tunnel kiln

    Yu Zhang

    2015-05-01

    Full Text Available The kiln car is widely used as a kind of transport equipment in the current ceramic industry, and it is heated to the firing temperature and cooled down to the ambient temperature with products in the tunnel kiln. And the burning of the ceramics requires a lot of energy, and the efficiency is relatively low within 30% or even less. In addition, the mass ratio between car and ware can be more than 50%. So the energy loss of car also occupies a great part in total energy consumption. In this work, a mathematical model will be created to describe the temperature distribution inside the kiln car while it travels through the tunnel kiln. All the used parameters are from real ceramic industry. The operative process is assumed as a countercurrent heat exchanger. Both the convection and radiation are considered as boundary condition in the model. Furthermore, the thermal results of car and the specific energy consumption of car in the standard case will be demonstrated. Finally, the influences of different thermal physical parameters on the energy consumption of car will be investigated, and the possible optimization measures of car are proposed through comparing the different specific energy losses.

  2. Investment opportunity : the FPL low-cost solar dry kiln

    George B. Harpole

    1988-01-01

    Two equations are presented that may be used to estimate a maximum investment limit and working capital requirements for the FPL low-cost solar dry kiln systems. The equations require data for drying cycle time, green lumber cost, and kiln-dried lumber costs. Results are intended to provide a preliminary estimate.

  3. 52 KILN EFFICIENCY AND INSULATION. Anthony Obiy Etuokwu ...

    HP-G61

    52. KILN EFFICIENCY AND INSULATION. Anthony Obiy Etuokwu. Department of Fine and Industrial Arts,. Niger Delta University,. Wilberforce Island, Bayelsa State. etuokwutony@yahoo.com. Introduction. The kiln is an insulating fire chamber that has the ability to retain the heat that is generated into it, and utilizes such heat ...

  4. New developments of high dust-SCR technology in the cement industry results of pilot tests in Solnhofen and development state of a full scale SCR unit; Nouveaux developpements de la technologie SCR ''High Dust'' dans l'industrie du ciment - resultats de tests pilotes a Solnhoffen et etat de developpement d'une unite pilote a l'echelle

    Samant, G. [Lurgi Energie und Entsorgung GmbH, Frankfurt (Germany); Sauter, G. [Soinhofer Portland Zementwerke AG, Solnhofen (Germany); Haug, N. [Agence Federale de l' Environnement, Berlin (Germany)

    2001-07-01

    The production of clinker in the cement industry involve the formation of nitrous oxides, and the emission limits are becoming more stringent from year to year. The added up total NOx emissions from the European cement industry amounts at present approx. 450.000 Mg/year. As such it is high time for the decision to develop and implement a technology to reduce NOx-emissions. At present SCR technology which is implemented in the glass industry, waste incineration and power plants seems to be the best economical and ecological solution for cement industry. In the period time from 1997 to the end of 1999 pilot plant test work was carried out by the companies 'Solnhofer Portland Zementwerke AG' and 'mg Engineering Lurgi' in the cement plant in Solnhofen. The results of pilot plan test work show that NOx reduction rates above 90% with NH{sub 3} slip less then 5 vppm can be achieved. The results of the test work with different type of catalysts are discussed. Based on the results of the test work a suitable SCR-process for cement industry is developed. At present a High-Dust-SCR demonstration plant at 'Solnhofer Portland Zementwerke AG' with the help of German Federal Environmental Agency, UBA-Berlin, is under commissioning and going on stream. (authors)

  5. Community Geothermal Technology Program: Experimental lumber drying kiln. Final report

    Leaman, D.; Irwin, B.

    1989-10-01

    Goals were to demonstrate feasibility of using the geothermal waste effluent from the HGP-A well as a heat source for a kiln operation to dry hardwoods, develop drying schedules, and develop automatic systems to monitor/control the geothermally heated lumber dry kiln systems. The feasibility was demonstrated. Lumber was dried in periods of 2 to 6 weeks in the kiln, compared to 18 months air drying and 6--8 weeks using a dehumidified chamber. Larger, plate-type heat exchangers between the primary fluid and water circulation systems may enable the kiln to reach the planned temperatures (180--185 F). However, the King Koa partnership cannot any longer pursue the concept of geothermal lumber kilns.

  6. NAA study on characteristics and sources of raw materials of celadon bodies from Qingliangsi kiln and Zhanggongxiang kiln

    Wu Zhanjun; Zhao Weijuan; Lu Xiaoke; Li Guoxia; Guo Min; Xie Jianzhong; Qiu Xia; Feng Songlin

    2007-01-01

    Thirty-seven samples of ancient Chinese Ru porcelain bodies unearthed from Qingliangsi kiln (containing 32 Ru official porcelain bodies and 5 Ru folk porcelain bodies), thirty-two samples of ancient celadon bodies from Zhanggongxiang kiln, and fourteen samples of modern mineral, were selected and analyzed by neutron activation analysis (NAA) method. Twenty-three elements were measured. The data of these elemental contents were processed by scatter analysis and principle component analysis methods in order to determine the characteristics and sources of the raw materials of the celadon porcelain bodies from the foregoing two kilns. The results show that Fe, Ce, Ba, Ta, Th, La, Sm and Cr are the fingerprint elements to distinguish the ancient Ru official porcelain bodies from ancient celadon bodies of Zhanggongxiang kiln. The sources of the raw material of the ancient Ru official porcelain bodies from Qingliangsi kiln are more concentrated and stable than those from Zhanggongxiang kiln. The Ru folk porcelain bodies and the Ru official porcelain bodies from Qingliangsi kiln have the same provenance, both sources of which are local. The raw material origins of the ancient celadon bodies from Zhanggongxiang kiln is a little dispersed and the compositions of the raw material are different from the Ru porcelains, but the distance is not far away from each other. (authors)

  7. Oil-Sludge Extended Asphalt Mastic Filled with Heavy Oil Fly Ash and Cement Waste for Waterproofing

    H.I. Al-Abdul Wahhab

    2014-12-01

    Full Text Available Recycling as an economic disposal process for many hazardous waste materials has become a popular means of conserving our planet’s scarce and diminishing natural resources. This paper is a study of the influence of oil sludge (OS on the physical behavior and performance of asphalt filled with heavy oil fly ash (HOFA, cement kiln dust (CKD and limestone dust (LMD. Conventional asphalt consistency tests in addition to a new bond strength (BS test were conducted on the modified asphalt mastics. The results were statistically analyzed and assessed in accordance with American Society for Testing and Materials (ASTM D 332 and ASTM D 449 specifications. Too much OS resulted in strength deterioration of the asphalt mastic, which can be compensated for by filling the mastic with HOFA. OS interacts constructively with the fillers to improve their effectiveness in raising the softening point (SP and viscosity of the asphalt, and also in reducing its penetration and ductility. Even though sludge mastics hold promise as suitable composites for damp proofing and waterproofing, the resulting low flash point (FP and SP of some of these mastics make their suitability for roofing applications questionable.

  8. Neutron activation analysis of the arovenance relation of tang tri-color glazed potteryies of huangye kiln and yaozhou kiln

    Li Guoxia; Zhao Weijuan; Gao Zhengyao; Xie Jianzhong; Guo Min

    2006-01-01

    The technique of neutron activation analysis (NAA) has been employed to measure the content of 29 kinds of elements in the Tang Tri-color glazed potteryies of Huangye kiln and Yaozhou kiln. Then a fuzzy cluster analysis has been conducted to the NAA data. The results indicate that the places of origin of raw materials of body samples in the Tang Tri-color glazed potteryies of Huangye kiln are very concentrated, and that the places of origin of raw materials of body and glaze samples are scattered the places of origin of raw materials of the body and glaze raw material cover that of the body raw material. The source of raw materials of samples in the Tang Tri-color glazed potteryies of Huangye kiln is obviously different from that of samples in the Tang Tri-color glazed potteryies of Yaozhou kiln. (authors)

  9. Drying hard maple (Acer saccharum L.) lumber in a small dehumidification kiln

    Neal. Bennett

    2013-01-01

    Portable sawmill owners quickly recognize the advantage to kiln drying lumber they produce. Having the ability to provide properly kiln-dried lumber opens new market opportunities and can increase profit margins. However, the construction and operation of a dry kiln must be economical and simple. A small dehumidification dry kiln constructed and tested in Princeton, WV...

  10. Evaluating a Small Structural Insulated Panel (SIP) Designed Solar Kiln in Southwestern New Mexico - Part 1

    Richard D. Bergman; Ted E.M. Bilek

    2012-01-01

    With increasing energy costs, using small dry kilns for drying lumber for small-volume value-added wood products has become more of an option when compared with conventional drying. Small solar kilns are one such option, and a number of solar kiln designs exist and are in use. However, questions remain about the design and operation of solar kilns, particularly during...

  11. Modernization of Byuzmeyinsky Cement Plant

    NONE

    2001-03-01

    With an objective of saving energy and reducing greenhouse gas emission, investigations and discussions were given on a modernization project for Byuzmeyinsky Cement Factory, the only cement factory in Turkmenistan. Byuzmeyinsky Cement Factory uses the wet process which consumes a large amount of energy, is inferior in production efficiency and quality, and discharging a great amount of greenhouse effect gas. The present project will execute change of the raw material crusher into a vertical roll mill for one of the four wet kilns, and change of the facilities for raw material powder mixing and storing and clinker manufacturing into dry-type facilities using the NSP system. As a result of the discussions, the energy saving effect would be 86,321 tons of crude oil equivalent annually, and the greenhouse gas emission reducing effect would be 224,467 t-CO2 annually. The total fund amount required for the project is estimated to be 90,211,000 dollars. With regard to the profitability, the internal financial profit rate would be 9.71% after tax, and the ROE would be 18.62%, whereas the project is considered feasible. (NEDO)

  12. Use of MRF residue as alternative fuel in cement production.

    Fyffe, John R; Breckel, Alex C; Townsend, Aaron K; Webber, Michael E

    2016-01-01

    Single-stream recycling has helped divert millions of metric tons of waste from landfills in the U.S., where recycling rates for municipal solid waste are currently over 30%. However, material recovery facilities (MRFs) that sort the municipal recycled streams do not recover 100% of the incoming material. Consequently, they landfill between 5% and 15% of total processed material as residue. This residue is primarily composed of high-energy-content non-recycled plastics and fiber. One possible end-of-life solution for these energy-dense materials is to process the residue into Solid Recovered Fuel (SRF) that can be used as an alternative energy resource capable of replacing or supplementing fuel resources such as coal, natural gas, petroleum coke, or biomass in many industrial and power production processes. This report addresses the energetic and environmental benefits and trade-offs of converting non-recycled post-consumer plastics and fiber derived from MRF residue streams into SRF for use in a cement kiln. An experimental test burn of 118 Mg of SRF in the precalciner portion of the cement kiln was conducted. The SRF was a blend of 60% MRF residue and 40% post-industrial waste products producing an estimated 60% plastic and 40% fibrous material mixture. The SRF was fed into the kiln at 0.9 Mg/h for 24h and then 1.8 Mg/h for the following 48 h. The emissions data recorded in the experimental test burn were used to perform the life-cycle analysis portion of this study. The analysis included the following steps: transportation, landfill, processing and fuel combustion at the cement kiln. The energy use and emissions at each step is tracked for the two cases: (1) The Reference Case, where MRF residue is disposed of in a landfill and the cement kiln uses coal as its fuel source, and (2) The SRF Case, in which MRF residue is processed into SRF and used to offset some portion of coal use at the cement kiln. The experimental test burn and accompanying analysis indicate

  13. 40 CFR 265.314 - Special requirements for bulk and containerized liquids.

    2010-07-01

    ... (volcanic glass); expanded volcanic rock; volcanic ash; cement kiln dust; fly ash; rice hull ash; activated... density polyethylene (HDPE), polypropylene, polystyrene, polyurethane, polyacrylate, polynorborene...

  14. Thermal treatment of medical waste in a rotary kiln.

    Bujak, J

    2015-10-01

    This paper presents the results of a study of an experimental system with thermal treatment (incineration) of medical waste conducted at a large complex of hospital facilities. The studies were conducted for a period of one month. The processing system was analysed in terms of the energy, environmental and economic aspects. A rotary combustion chamber was designed and built with the strictly assumed length to inner diameter ratio of 4:1. In terms of energy, the temperature distribution was tested in the rotary kiln, secondary combustion (afterburner) chamber and heat recovery system. Calorific value of medical waste was 25.0 MJ/kg and the thermal efficiency of the entire system equalled 66.8%. Next, measurements of the pollutant emissions into the atmosphere were performed. Due to the nature of the disposed waste, particular attention was paid to the one-minute average values of carbon oxide and volatile organic compounds as well as hydrochloride, hydrogen fluoride, sulphur dioxide and total dust. Maximum content of non-oxidized organic compounds in slag and bottom ash were also verified during the analyses. The best rotary speed for the combustion chamber was selected to obtain proper afterburning of the bottom slag. Total organic carbon content was 2.9%. The test results were used to determine the basic economic indicators of the test system for evaluating the profitability of its construction. Simple payback time (SPB) for capital expenditures on the implementation of the project was 4 years. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Effect of thallium in cement oven dusts on the growth and thallium uptake of several culture plants for the determination of thallium thresholds in plants and soils. Wirkung des Thallium in Zementofenstaeuben auf Wachstum und Thallium-Aufnahme mehrerer Kulturpflanzen zur Ermittlung von Thallium-Grenzwerten in Pflanzen und Boeden

    Makridis, H

    1987-02-27

    After preliminary experiments in the methodology of Tl-analysis in plants and soils, phytotoxic Tl-concentrations and specific toxicity symptoms of different crops (beans, rape) have been determined in hydroponic culture with TlCl/sub 3/.H/sub 2/O. In pot experiments, critical Tl-levels were evaluated with regard to yield and Tl-uptake of plants on different soils, as a basis for the classification of soilcontamination by Tl originating form cement klink dust. The latter is a main source of Tl-emissions. Thus, several dusts with differing Tl-concentrations were tested in extensive two-year pot-experiments with different plants, and critical levels for lime- and potash- containing dusts have been elaborated. (orig./MG)

  16. Development of low radio-activated cement. Characteristics of cement and clinker that decreased liquid phase content

    Ichitsubo, Koki

    2008-01-01

    Low radio-activated cement was developed by decreasing the parent elements of radionuclides in the materials. The characteristics of products, decreasing method of Na, Eu and Co in cement, design, tests, evaluation, and analysis of low radio-activated cement clinker are reported. In order to decrease the content of Na, Eu and Co, the raw materials have to include natural materials such as limestone and silica stone. The production method is the same as white cement. The low radio-activated cement produced by rotary kiln showed 4.9% C 3 A, 1.1% C 4 AF, 26.9% C 3 S and 61.0% C 2 S, which values were standardized by the Japanese Industrial Standards (JIS) of low temperature Portland cement. Another product that decreased a little more liquid phase content showed 4.0% C 3 A, 1.0% C 4 AF, 32.3% C 3 S and 56.5% C 2 S, which was standardized by JIS of sulfate resisting Portland cement. In the case of decommissioning reactor constructed by the low radio-activated cement, the whole amount of waste cement will be no more than the clearance level. (S.Y.)

  17. Brick-Burning Kiln from the Zhaiyk Fortified Site

    Kalmenov Murat D.

    2013-12-01

    Full Text Available The article contains a description of the brick-burning kiln, which was discovered during the 2012 excavations on the medieval Zhaiyk fortified site (Western Kazakhstan oblast. A similar object had been discovered on the site in 2002. Kilns of similar design were known on the vast territories of Southeastern Europe and Central Asia in the 10th-15th cc. In the 13th-15th centuries, they were widely spread in the territory of the Golden Horde. The analysis of their design, combined with written sources and ethnographic data, allows reconstructing the operation process of such kilns in general lines. The finds of kilns on the Zhaiyk settlement make it possible to suggest that in the 13th-14th centuries there existed a developed construction materials production in the territory of the settlement.

  18. Electrical signal transfer system for a rotary kiln

    Tyson, J.H.; Kennett, L.P.; Davidson, I.S.

    1985-01-01

    A rotary kiln has a number of thermocouples respectively sensing the kiln temperature at spaced locations and respectively connected to annular slip rings. Laterally facing peripheral surfaces of the rings are respectively cooperable with brush contacts connected to a bar and a fork which embraces a ring moveable axially with the rings. Thus on longitudinal expansion of the kiln the contacts are caused to move with the rings. The electric signals from the thermocouples are thus fed to stationary monitoring equipment. In a modification the ring sections are electrically isolated and each section is connected to a respective sensor. Position sensors may be used to detect the rotary position of the kiln. The invention can be applied to other sensors. (author)

  19. 40 CFR 63.1348 - Standards for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

    2010-07-01

    ... than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw and finish mills. 63.1348 Section 63.1348 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw and...

  20. Roller kiln with very low fluoride emission. The Ecokiln

    Reymer, P.S.; Denissen, A.M. [TNO TPD Materials Research and Technology, Eindhoven (Netherlands)

    2001-09-01

    In most European countries the limit for fluoride emission in ceramic kiln flue gases is set at 5 mg HF/m{sup 3} flue gas. In cooperation with Royal Mosa, Royal Sphinx, Gasunie in the Netherlands and Sacmi, Italy, a roller kiln has been developed which can operate below the fore-mentioned limit. Also, a flue gas cleaning device is not necessary. 4 refs.

  1. Drying firewood in a temporary solar kiln: a case study.

    George R. Sampson; Anthony F. Gasbarro

    1986-01-01

    A pilot study was undertaken to determine drying rates for small diameter, unsplit paper birch firewood that was dried: (1) in a conventional top-covered pile; (2) in a simple, temporary solar kiln; and (3) in tree length. Drying rates were the same for firewood piles whether they were in the temporary solar kilns or only covered on top to keep rain or snow from...

  2. Prevalence of chest symptoms amongst brick kiln migrant workers and care seeking behaviour: a study from South India.

    Thomas, Beena E; Charles, Niruparani; Watson, Basilea; Chandrasekaran, V; Senthil Kumar, R; Dhanalakshmi, A; Wares, Fraser; Swaminathan, Soumya

    2015-12-01

    Early detection and treatment of tuberculosis (TB) have been key principles of TB control. However, this can be a challenge with 'hard to reach' populations such as migrants. Brick kiln workers are one such group of migrants who are exposed to smoke, heat and dust from brick kilns which are one of the major causes of respiratory illnesses. A cross-sectional community based study was carried out in Thiruvallur, Tamil Nadu, South India, from August 2011 to June 2012. A total of 4002 individuals from 55 brick kiln chambers were interviewed to determine the prevalence of chest symptoms and care seeking behaviour patterns. Three hundred and seventy-seven (9.4%) chest symptomatics were identified. The most significant variables associated with chest symptoms were illiteracy, alcohol abuse and heavy smoking. Of the chest symptomatics identified, 50.4% took action to get relief from their symptoms. The duration of over 6-month stay in the chamber was significantly associated with taking action (OR, 5.5, 95% CI: 2.3, 13.3). The TB control programme needs to further explore how to extend its services to such 'hard to reach' groups. Active case finding to ensure early diagnosis and treatment initiation amongst such groups needs consideration. © The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Impact of coal and rice husk ash on the quality and chemistry of cement clinker

    Nawaz, S.; Kanwal, S.; Rahim, U.; Sheikh, N.; Shahzad, K.

    2012-01-01

    Utilization of rice husk as an alternative fuel for coal is of interest due to its availability in huge quantities in Pakistan and also because its combustion is environmental pollution friendly as it generates much less SOX due to its much lower sulphur content (0.1-0.3%) compared to sulphur content in coals, particularly indeginous coals ranging from 0.6-14.8%. The purpose of present study was to examine the impact of co-firing of rice husk and coal on the quality of cement clinker so as to substitute expensive imported coal with the abundantly available cheaper rice husk to reduce the cost of production of the cement. For this investigation raw feed mix (mixture of limestone, clay, bauxite and laterite in predetermined proportions) used for cement manufacture was mixed with predetermined varying proportions of coal ash and rice husk ash and placed inside a muffle furnace at 1200 degree C - 1500 degree C i-e the temperatures prevailing in the industrial cement kilns, for various periods of time to obtain cement clinker. The quality and chemistry of cement clinker thus produced in the laboratory was experimentally studied to ensure the quality of cement clinker that would be obtained by co-firing of rice husk and coal in different proportions in industrial cement kilns as the coal ash and rice husk ash produced during combustion will get mixed with cement clinker in industrial kilns. The results indicated that there was decrease in the Lime Saturation Factor, Free Lime and Tricalcium Silicate (C3S) content and increase in the Dicalcium Silicate (C2S) content by increasing the rice husk ash and decreasing the coal ash proportion in the clinker. (author)

  4. The effect of fly ash and coconut fibre ash as cement replacement materials on cement paste strength

    Bayuaji, R.; Kurniawan, R. W.; Yasin, A. K.; Fatoni, H. AT; Lutfi, F. M. A.

    2016-04-01

    Concrete is the backbone material in the construction field. The main concept of the concrete material is composed of a binder and filler. Cement, concrete main binder highlighted by environmentalists as one of the industry are not environmentally friendly because of the burning of cement raw materials in the kiln requires energy up to a temperature of 1450° C and the output air waste CO2. On the other hand, the compound content of cement that can be utilized in innovation is Calcium Hydroxide (CaOH), this compound will react with pozzolan material and produces additional strength and durability of concrete, Calcium Silicate Hydrates (CSH). The objective of this research is to explore coconut fibers ash and fly ash. This material was used as cement replacement materials on cement paste. Experimental method was used in this study. SNI-03-1974-1990 is standard used to clarify the compressive strength of cement paste at the age of 7 days. The result of this study that the optimum composition of coconut fiber ash and fly ash to substitute 30% of cement with 25% and 5% for coconut fibers ash and fly ash with similar strength if to be compared normal cement paste.

  5. A dust-free dock

    Merrion, D. [E & F Services Ltd. (United Kingdom)

    2002-10-01

    This paper describes the process of unloading coal, petcoke and other dusty products in environmentally-sensitive areas. It presents a case study of the deepwater Port of Foynes on the west coast of Ireland which imports animal feed, fertiliser, coal and cement clinker, where dockside mobile loaders (DMLs) have eliminated spillage and controlled dust, and a record case study of the Humber International Terminal in the UK, where air curtinas, dust suppression grids and EFFEX{reg_sign} filters overcome the dust problems. 2 photos.

  6. Practical use of solar heating-dehumidification dry kiln

    Kobayashi, Yoshinori

    1988-06-01

    In order to decrease the energy cost for drying, a solar-dehumidification dry kiln which used the dehumidification dry process together with the solar thermal drier was developed and tested. In the daytime the drying temperature rose up to 60/sup 0/C in summer and 40/sup 0/C in winter, and it was kept higher by 15 to 20/sup 0/C than the outside temperature at night. Owing to the adoption of the combination of direct solar heating and exhausting highly humid air, it was not necessary to operate the dry kiln in the day time. Average electrical energy consumption which was consumed to 15% moisture content from the raw lumber was about 73kWh/m/sup 3/ in summer which was lowest, about 87kWh/m/sup 3/ in winter. Energy cost required for the solar dehumidification dry kiln is 1/2 to 2/3 of that of the conventional dehumidification dry kiln. The solar-dehumidification dry kiln has a merit of cheaper operating cost in the low energy cost and reduced drying time. (7 figs, 1 tab, 6 refs)

  7. Comparative life cycle analysis of cement made with coal vs hazardous waste as fuel

    Kelly, K.E.; Beeh, J.

    1994-01-01

    The purpose of this life cycle analysis (LCA) is to compare the life cycle of cement made with coal, the standard fuel used in a cement kiln, versus cement made with hazardous waste-derived fuels. The intent of the study is to determine whether the use of hazardous waste as a fuel in the production of cement could result in an increase in detrimental effects to either health or environment. Those evaluated for potential adverse effect include cement kiln workers, waste transporters, and consumers using the final product for private use. The LCA stages included all the processes involved with cement, including raw materials acquisition, transportation, manufacturing, packaging, distribution, use, recycling, and disposal. The overall conclusions of the LCA are that use of waste fuels instead of coal to make cement: (1) does not increase, and may reduce, the concentration of contaminants in the cement product due to the reduction or elimination of the use of coal; (2) reduces or eliminates use of non-renewable fossil fuels, such as coal, as well as the environmental damage and impacts associated with coal mining; (3) provides a more environmentally beneficial means of destroying many types of wastes than alternative treatment methods, including incineration, thus decreasing the need for waste treatment facilities and capacity; (4) decreases overall emissions during transportation but may increase the overall consequences of accidents or spills; (5) results in cement product which may be packaged, transported, distributed and used in the same manner as cement product made with coal; (6) lowers the cost of cement production; and (7) overall appears to result in less health and environmental impacts

  8. Identifying improvement potentials in cement production with life cycle assessment.

    Boesch, Michael Elias; Hellweg, Stefanie

    2010-12-01

    Cement production is an environmentally relevant process responsible for 5% of total anthropogenic carbon dioxide emissions and 7% of industrial fuel use. In this study, life cycle assessment is used to evaluate improvement potentials in the cement production process in Europe and the USA. With a current fuel substitution rate of 18% in Europe and 11% in the USA, both regions have a substantial potential to reduce greenhouse gas emissions and save virgin resources by further increasing the coprocessing of waste fuels. Upgrading production technology would be particularly effective in the USA where many kiln systems with very low energy efficiency are still in operation. Using best available technology and a thermal substitution rate of 50% for fuels, greenhouse gas emissions could be reduced by 9% for Europe and 18% for the USA per tonne of cement. Since clinker production is the dominant pollution producing step in cement production, the substitution of clinker with mineral components such as ground granulated blast furnace slag or fly ash is an efficient measure to reduce the environmental impact. Blended cements exhibit substantially lower environmental footprints than Portland cement, even if the substitutes feature lower grindability and require additional drying and large transport distances. The highest savings in CO(2) emissions and resource consumption are achieved with a combination of measures in clinker production and cement blending.

  9. Analysis of Drying Process Quality in Conventional Dry-Kilns

    Sedlar Tomislav; Pervan Stjepan

    2010-01-01

    This paper presents testing results of drying quality in a conventional dry kiln. Testing is based on a new methodology that will show the level of success of the drying process management by analyzing the quality of drying process in a conventional dry kiln, using a scientifi cally improved version of the check list in everyday practical applications. A company that specializes in lamel and classic parquet production was chosen so as to verify the new testing methodology. A total of 56 m3 of...

  10. Lime Kiln Modeling. CFD and One-dimensional simulations

    Svedin, Kristoffer; Ivarsson, Christofer; Lundborg, Rickard

    2009-03-15

    The incentives for burning alternative fuels in lime kilns are growing. An increasing demand on thorough investigations of alternative fuel impact on lime kiln performance have been recognized, and the purpose of this project has been to develop a lime kiln CFD model with the possibility to fire fuel oil and lignin. The second part of the project consists of three technical studies. Simulated data from a one-dimensional steady state program has been used to support theories on the impact of biofuels and lime mud dryness. The CFD simulations was carried out in the commercial code FLUENT. Due to difficulties with the convergence of the model the calcination reaction is not included. The model shows essential differences between the two fuels. Lignin gives a different flame shape and a longer flame length compared to fuel oil. Mainly this depends on how the fuel is fed into the combustion chamber and how much combustion air that is added as primary and secondary air. In the case of lignin combustion the required amount of air is more than in the fuel oil case. This generates more combustion gas and a different flow pattern is created. Based on the values from turbulent reaction rate for the different fuels an estimated flame length can be obtained. For fuel oil the combustion is very intense with a sharp peak in the beginning and a rapid decrease. For lignin the combustion starts not as intense as for the fuel oil case and has a smoother shape. The flame length appears to be approximately 2-3 meter longer for lignin than for fuel oil based on turbulent reaction rate in the computational simulations. The first technical study showed that there are many benefits of increasing dry solids content in the lime mud going into a kiln such as increased energy efficiency, reduced TRS, and reduced sodium in the kiln. However, data from operating kilns indicates that these benefits can be offset by increasing exit gas temperature that can limit kiln production capacity. Simulated

  11. Fiscal 1999 research report. Basic research on joint implementations promotion (Feasibility study of modification for Tehran Cement Co., Ltd., Iran); 1999 nendo kyodo jisshi nado suishin kiso chosa hokokusho. Iran koku Teheran cement sha kaizo F/S

    NONE

    2000-03-01

    The feasibility study was started upon a request made by the Iranian Ministry of Energy involving the No. 7 kiln of the above said company. It was then concluded, after assessing the degree of urgency of supply and demand and the magnitude of loss due to reduced production because of the on-site modification work, that it was not practical to begin the project immediately. Under the circumstances, various studies were made about the feasibility of modification of the whole production process of the No. 1 kiln through No. 7 kiln, and a procedure was presented, to be described below. The procedure will consist of Phase I wherein the No. 3 wet kiln is converted into an NSP (new suspension preheater) dry kiln, Phase II wherein the No. 7 SP (suspension preheater) dry kiln is converted in to an NSP kiln, and Phase III wherein the No. 4 SP dry kiln is converted into a clinker cooler. Under this procedure, the modernization of the Tehran Cement Co., Ltd., facilities will be accomplished without causing production loss. After the completion of the project, an annual yield of 3.6-million tons will be achieved, with productivity to be improved by 26.4% over the current theoretical capacity or by 54.8% over the actual average for the past 5 years. There will be a sustained conservation of 25,356 tons/year in terms of oil. Application of CDM (clean development mechanism) to this project will be extremely effective in reducing greenhouse gas and in improving profitability. (NEDO)

  12. Ring Formation in Lime Kilns; Ringbildning i Mesaugnar II

    Dhak, Janice [AaF-Process AB, Stockholm (Sweden)

    2003-07-15

    The key to a cost efficient and high performance pulp production is low variations in the production level. Despite the fact that all pulp mills always work with improvements to eliminate problems with ring formations, AaF has at several mill seen that the operation of a lime kiln still often is disturbed by ring formation. In 1999 AAF made an extensive investigation of more than 10 lime kilns in Sweden, considering operational data, kiln data and lime chemical analyzes. The result pointed out the importance of how the lime kiln is operated and that dead load and contaminants in the lime was less important. The report suggested that it is the difference in the temperature between the flue gas and the lime that is of importance. There are no quantified process values available that guides for a 'best practice' way to run a lime kiln to avoid ring formation. The goal with this project has been to develop a strategy for operation of a kiln in a way that lowers the risk for ring formation. The results from simulations of a number of lime kilns in this project could not proof that a low difference in the temperature between the flue gas and the lime was the main cause of problems with ring formation and thus it was not possible to quantify the optimal difference to avoid rings. Probably the most important information from the simulations was that it is not the temperature difference in number of degrees that is of importance, rather the fact that the temperature difference in the kalcining zone varies, and time to time reach below the critical level were lime occasionally is cooled down. It can be the case if the temperature profile of the flue gas temporarily changes or if the lime mud temperature profile is changed. The reason for changes in the temperature profile is discussed in the report. The most important factors discussed are: Variations in the energy input e.g. oil and methanol/strong gases in cocombustion. One single fuel is easier to control

  13. Move towards bag filter units in kiln dedusting; Vers l'utilisation de filtres a manches en four a ciment

    Schobesberger, M.

    2000-02-01

    Dedusting of kiln gases has become a major concern for cement companies worldwide due to the more and more stringent environmental standards. This short paper draws out an overview of the recent trends in dedusting techniques using bag filters. A comparison is made between different factories and their experience in the use of bag filters made of different materials or used in different operating conditions. The lifetime of these filters is the main problem to deal with and depends on various factors such as the the material used, the air to cloth ratio, the flow rate, temperature, and moisture of the flue gases. (J.S.)

  14. Study of provenance properties on ancient celadon of different kilns with NAA

    Feng Songlin; Fan Dongyu; Feng Xiangqian; Xu Qing; Cheng Lin; Lei Yong; Shen Yueming; Zhang Wenjiang; Zhua Zhenxi

    2005-01-01

    Provenance characteristic is an important scientific parameter to identify ancient porcelain wares unearthed from sites and graves. The porcelain samples of Si-Long-Kou Yue kiln of Zhejiang Province, Hong-Zhou kiln of Jiangxi Province and Yao-Zhou kiln of Shanxi Province have been analyzed with neutron activation analysis (NAA). The experimental data were studied with statistic methods. The results show that the chemical compositions of porcelain body samples for three kilns were different. The difference was able to be identified. The body materials of both Si-Long-Kou Yue kiln and Hong-Zhou kiln of Jiangxi were similar. The samples of Yao-Zhou kiln in north of China existed obvious difference. (authors)

  15. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  16. Adoption of improved fish smoking kilns and recommendations in ...

    Adoption of improved fish smoking kilns and recommendations in North-Western Nigeria. P I Bolorunduro, O A Owolabi, O C Jegede. Abstract. No Abstract. African Journal of Livestock Extension Vol. 4 2005: pp. 89-94. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  17. EVALUATION OF A KILN INCORPORATING AN OSCILLATING PLATE AIRFLOW SYSTEM

    Campean,Mihaela; Marinescu,Ion; Ispas,Mihai

    2003-01-01

    Boards of spruce (Picea abies) were dried in a pilot kiln with an oscillating plate that provides -"alternating air movement in the stack". The paper outlines the airflow concept and provides results for drying time and quality.It is suggested that the system has certain advantages which make it suitable as an alternative to conventional drying, especially for small-sized enterprises

  18. Operating results of Kosmos Cement's O-SEPA separator for raw grinding

    Ireland, T C [Consultec Ltd., Toronto (CA); Schultz, G K [Southdown Incorporated, Houston, TX (US)

    1991-01-01

    High efficiency separators were first introduced in the cement industry to improve the energy efficiency of finish grinding circuits. Lately, however, a great deal of interest has been focused on improving the energy efficiency of raw grinding circuits. High efficiency separators have successfully been installed in roller mills as well as in ball mill raw grinding circuits. This paper describes the operating experience of the first installation in North America using a high efficiency separator in a raw grinding circuit. This installation, commissioned in 1988 at the Louisville, Kentucky plant of Kosmos Cement, uses a conventional 4500 HP ball mill and a high efficiency dynamic separator to produce raw meal for a preheater kiln as well as high fineness limestone for sulphur scrubbing in a nearby power plant. The system uses kiln exhaust gases for drying both in the mill and in the separator. (author).

  19. Increasing the energy performance of cement works; Des solutions pour ameliorer la performance energetique des cimenteries

    Bolliger, M.; Gallestey, E.; Crosiey, G.; Kiener, M.

    2009-07-01

    Cement works are consuming much thermal and electric energy and this affects the production cost. In the past years, much effort has been put on how to reduce this consumption and cost. Alternative fuels and raw materials have been introduced. As a result the optimization of the production process has become more sophisticated. This article describes a series of computerized tools developed by the company ABB Ltd., which were designed to improve quality assurance and productivity. They apply to the whole production process, including the rotary kiln, the pollutants' emissions in exhaust gases, the numerous ventilators and the crushers. Variable speed drives for ventilators and temperature control in the kiln are amongst the key factors. The optimizers also consider the different cement qualities to be produced in successive batches and the time-dependent electricity prices.

  20. Opportunities for Energy Efficiency and Demand Response in the California Cement Industry

    Olsen, Daniel; Goli, Sasank; Faulkner, David; McKane, Aimee

    2010-12-22

    This study examines the characteristics of cement plants and their ability to shed or shift load to participate in demand response (DR). Relevant factors investigated include the various equipment and processes used to make cement, the operational limitations cement plants are subject to, and the quantities and sources of energy used in the cement-making process. Opportunities for energy efficiency improvements are also reviewed. The results suggest that cement plants are good candidates for DR participation. The cement industry consumes over 400 trillion Btu of energy annually in the United States, and consumes over 150 MW of electricity in California alone. The chemical reactions required to make cement occur only in the cement kiln, and intermediate products are routinely stored between processing stages without negative effects. Cement plants also operate continuously for months at a time between shutdowns, allowing flexibility in operational scheduling. In addition, several examples of cement plants altering their electricity consumption based on utility incentives are discussed. Further study is needed to determine the practical potential for automated demand response (Auto-DR) and to investigate the magnitude and shape of achievable sheds and shifts.

  1. PREPP [Process Experimental Pilot Plant] rotary kiln seals: Problem and resolution

    Drexler, R.L.

    1990-01-01

    The Process Experimental Pilot Plant (PREPP) is a facility designed to demonstrate processing of low level chemical and transuranic hazardous waste. The plant includes equipment for handling the incoming waste containers, shredding, incineration and cooling the waste, grouting the residue and scrubbing and filtration of the off gas. The process incinerator is a rotary kiln approximately 8-1/2 ft diameter and 25 ft long with a rotary seal assembly at each end. Each seal assembly consists of a primary, secondary and tertiary seal, with a positive air pressure between primary and secondary seals to prevent out-leakage from the kiln. The kiln operates at 0.5 inch water negative pressure. From the very outset the kiln seals exhibited excessive drag which taxed the kiln drive capacity and excessive in-leakage which limited kiln temperature. An engineering evaluation concluded that the original seals supplied by the kiln vendor could not accommodate expansion and centerline shift of the kiln resulting from heatup of the kiln and its support system. A totally new concept kiln seal design has been generated to replace the (modified) original seals. This new seal system has been designed to provide a very tight long lasting seal which will accommodate the 1.5 inch axial shift and up to 1 inch radial movement of the kiln shell. Design lifetime of the seal is 10,000 operating hours between major maintenance services while maintaining an acceptable leak rate hot or cold, rotating or stopped. The design appears adaptable to any size kiln and is suitable for retrofit to existing kilns. A one-third scale prototype seal assembly is being built to verify the concept prior to construction of the 10 ft diameter seals for the PREPP rotary kiln. 4 figs

  2. Front line of cement technolgy and control. Part 5. ; Baking process and chemical reactions. Cement saisentan sono gijutsu to kanri 5. ; Shosei katei to kagaku hanno

    Hirai, M. (Ube Industries, Ltd., Yamaguchi (Japan))

    1990-06-01

    The baking process in cement production means the process that the raw materials which were mixed and pulverized in the raw material preparation process are charged into a reaction furnace which is called kiln, and clinders (intermediate product of cement) are generated. It is the process which affects quality as well as production cost of cement more significantly than anything else. In this article, an outline of the above baking facilities, how the raw materials change and clinkers are generated therein, and how they are controlled are introduced. Clinkers are composed of such products as alite, belite, aluminate and ferrite, etc. which were generated after decomposition reactions of such raw materials as lime stone, clay, silica rock and iron oxide in the above kiln. The essential ponts of the process control which makes the generation reactions of clinker compounds efficiently are such two points as well balanced raw materials to be charged into the baking facilities and stable operation of such facilities. The quality of cement which is required as finished goods is achieved by the quality control at each intermediate process and the quality tests of cement. 5 refs., 10 figs., 2 tabs.

  3. Lunar cement

    Agosto, William N.

    1992-01-01

    With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

  4. Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion

    Stephanie Lucero Konopa; James A. Mulholland; Matthew J. Realff; Paul M. Lemieux [Georgia Institute of Technology, Atlanta, GA (United States). School of Civil and Environmental Engineering

    2008-08-15

    The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO{sub 2}), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particleboard combustion, consistent with its higher nitrogen content. S{sub 2} emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet. 13 refs., 5 figs., 1 tab.

  5. Assessment of the thermal performance and energy conservation opportunities of a cement industry in Indonesia

    Rasul, M.G.; Widianto, W.; Mohanty, B.

    2005-01-01

    A simple model is presented to assess the thermal performance of a cement industry with an integrated view to improve the productivity of the plant. The model is developed on the basis of mass, energy and exergy balance and is applied to an existing Portland cement industry in Indonesia. The data obtained from industry show that the burning efficiency and the second law efficiency of the kiln system are 52.07% and 57.07% respectively. Cooler efficiency and heat recovery efficiency are 47.75% and 51.2% respectively. The unaccounted loss at kiln system was found to be 1.85% and that of cooler system was 19%. The high loss at cooler was mainly due to the convection and radiation losses from the uninsulated cooler. Irreversibility of the system was found to be about 20%, which is due to the conversion from chemical to thermal energy. The thermal energy conservation opportunities are identified. This study show that by replacing industrial diesel oil (IDO) with waste heat recovery from kiln and cooler exhaust for drying of raw meal and fuel, and preheating of combustion air, a cement industry in Indonesia can save about 1.264 x 10 5 US dollars per year

  6. Stochastic Modelling and Self Tuning Control of a Continuous Cement Raw Material Mixing System

    Hannu T. Toivonen

    1980-01-01

    Full Text Available The control of a continuously operating system for cement raw material mixing is studied. The purpose of the mixing system is to maintain a constant composition of the cement raw meal for the kiln despite variations of the raw material compositions. Experimental knowledge of the process dynamics and the characteristics of the various disturbances is used for deriving a stochastic model of the system. The optimal control strategy is then obtained as a minimum variance strategy. The control problem is finally solved using a self-tuning minimum variance regulator, and results from a successful implementation of the regulator are given.

  7. Wood Dust

    Learn about wood dust, which can raise the risk of cancers of the paranasal sinuses and nasal cavity. High amounts of wood dust are produced in sawmills, and in the furniture-making, cabinet-making, and carpentry industries.

  8. Alternative Fuel for Portland Cement Processing

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  9. Modeling and simulation of cement clinkering process with compact internal burning of carbon

    Chen, Hanmin

    2014-01-01

    This article describes a mathematical model of the thermodynamic process for Cement Clinkering Process with Compact Internal Burning of Carbon. Using simplifying assumptions, results of calculations are presented based on relevant computerized numerical simulation for a set of typical process parameters obtained from the existing cement shaft kiln operation and the electrical furnace test on the mechanical and chemical performance of the compact coal containing cement raw meal pellets. It is revealed that, the carbon internal burning mode, combining fuel combustion and gas solid heat transfer together as well as preheating, calcining, clinkering and cooling of the raw pellets together, is the origin of the process superiority in respect of equipment simplicity, process enhancement, high energy efficiency and low pollution. Important process details are determined, e.g. the features and lengths of the process zones, the material residence time and the burning mode of carbon in each zone, the clinkering reaction course and the maximum burning temperature. It is concluded that numerical simulations could be useful tool for understanding the new process ideas, as well as conducting the technical development and optimizing the process design. - Highlights: • Twin subsystem model is used to simulate a new type of cement shaft kiln process. • Grain-particle structural model is used to describe the pellet solid gas reactions. • The process superiority resulted from the carbon internal burning mode is revealed. • A series of important process details are determined. • An unprecedented comprehensive picture for cement clinkering process is depicted

  10. Study of provenance character on ancient porcelain of Yue Kiln at Silongkou with NAA

    Jihao Zhu; Songlin Feng; Dongyu Fan; Xiangqian Feng; Qing Xu; Yueming Shen; Zhenxi Zhuo; Wenjiang Zhang

    2007-01-01

    Chemical composition is an important information of studying the provenance character of ancient pottery and porcelain. The ancient celadon samples produced in Later Tang (850-907 A.D.) to Former Southern Song (1127-1279 A.D.) have been analyzed with NAA. Its provenance characteristic was compared with that of Hongzhou Kiln of Jiangxi Province and Yaozhou Kiln of Shanxi Province in this paper. The experimental data were studied with statistic methods. The results indicated that the chemical compositions of ancient porcelain body samples made in three kilns were different. The difference is able to be identified. The porcelain body materials of both Silongkou Yue Kiln and Hongzhou Kiln were similar. The samples of Yaozhou kiln in north of China existed obvious difference. (author)

  11. Synthetic aggregates from combustion ashes using an innovative rotary kiln.

    Wainwright, P J; Cresswell, D J

    2001-01-01

    This paper describes the use of a number of different combustion ashes to manufacture synthetic aggregates using an innovative rotary 'Trefoil' kiln. Three types of combustion ash were used, namely: incinerated sewage sludge ash (ISSA); municipal solid waste incinerator bottom ash (MSWIBA-- referred to here as BA); and pulverised fuel ash (Pfa). The fine waste ash fractions listed above were combined with a binder to create a plastic mix that was capable of being formed into 'green pellets'. These pellets were then fired in a Trefoil kiln to sinter the ashes into hard fused aggregates that were then tested for use as a replacement for the natural coarse aggregate in concrete. Results up to 28 days showed that these synthetic aggregates were capable of producing concretes with compressive strengths ranging from 33 to 51 MPa, equivalent to between 73 and 112% of that of the control concrete made with natural aggregates.

  12. Integration Research on Gas Turbine and Tunnel Kiln Combined System

    Shi, Hefei; Ma, Liangdong; Liu, Mingsheng

    2018-04-01

    Through the integrated modeling of gas turbine and tunnel kiln combined system, a thermodynamic calculation method of combined system is put forward, and the combined system operation parameters are obtained. By this method, the optimization of the combined system is analyzed and the optimal configuration of the gas turbine is calculated. At the same time, the thermal efficiency of the combined system is analyzed, and the heat distribution and thermal efficiency of the system before and after the improvement are explained. Taking the 1500 kg/h ceramic production as an example, pointed out that if the tunnel kiln has a gas turbine with a power of 342 kw. The amount of electricity of the combined system that produced per unit volume of the fuel which consumes more than it used to will be 7.19 kwh, the system thermal efficiency will reach 57.49%, which higher than the individual gas turbine’s cycle thermal efficiency 20% at least.

  13. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Chest radiological findings in pakistani cement mill workers

    Meo, Sultan A.

    2003-01-01

    Chest radiological findings in Pakistani cement mill workers Even in the 21st century, in developing countries millions of people work daily in dusty environments. They are exposed to different types of health hazards namely, fumes, gases and dust, which are risk factors for developing occupational diseases. Therefore, the aim of this study was to perform chest radiology to determine the occupational hazards of cement dust on the lungs of cement mill workers. This study was carried out in the Department of Physiology, Faculty of Health and Medical Sciences, Hamdard University Karachi, Pakistan, during the period June to August 2000. In this study 50, apparently healthy volunteer male cement mill workers were randomly selected with an average of 13 years exposure with age ranging from 20-60 years. They were matched with 50, healthy male control subjects in terms of age, height, weight and socioeconomic status. Both groups met with exclusion criteria as per standard. Radiology was performed by Trophy radiology. Results: The present study demonstrated 12% of cases with interstitial lung disease and 2% of cases with pleural thickening and chronic bronchitis in cement mill workers. Conclusion: Exposure to cement dust causes interstitial lung disease, pleural thickening and chronic bronchitis in cement mill workers. (author)

  15. Mercury enrichment and its effects on atmospheric emissions in cement plants of China

    Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

    2014-08-01

    The cement industry is one of the most significant anthropogenic sources of atmospheric mercury emissions worldwide. In this study of three typical Chinese cement plants, mercury in kiln flue gas was sampled using the Ontario Hydro Method (OHM), and solid samples were analyzed. Particulate matter recycling, preheating of raw materials, and the use of coal and flue gas desulfurization derived gypsum contributed to emissions of Hg in the air and to accumulation in cement. Over 90% of the mercury input was emitted into the atmosphere. Mercury emission factors were 0.044-0.072 g/t clinker for the test plants. The major species emitted into the atmosphere from cement plants is oxidized mercury, accounting for 61%-91% of the total mercury in flue gas. The results of this study help improve the accuracy of the mercury emission inventory in China and provide useful information for developing mercury controls.

  16. 1998 data bank for kiln-dried red oak lumber

    Charles J. Gatchell; R. Edward Thomas; Elizabeth S. Walker

    1998-01-01

    A collection of 3,487 fully described, kiln-dried red oak boards totaling 20,021 board feet. The boards, which are straight or contain no more than ? inch of crook, are FAS, FAS ONE FACE (F1F), Selects, No. 1 Common, No. 2A Common, or No. 3A common. The boards were graded with the UGRS (Ultimate Grading and Remanufacturing System) computer program. After the grade was...

  17. Design of a Rotary Kiln for Production of Sarooj

    A. W. Hago

    2008-12-01

    Full Text Available Sarooj is a local term used for pozzolana. It has been used extensively as a hydraulic binder in buildings, hydraulic installations, forts and castles, and in the renovation of historical monuments. It is produced by burning specific clay soil that possesses adequate quantities of silica, alumina and iron oxides. In the past, the material was produced using a large amount of energy most of which is wasted by blowing winds. The burning system was usually thermally inefficient, and the output is rarely checked for quality. Test on products produced by using the traditional method may yield poor quality Sarooj due to inadequate burning or over burning or even insufficient grinding in the end. In this research, extensive experimentation has been performed on the method of production of Sarooj to determine the factors influencing Sarooj quality. Based on these factors, a new method of production is proposed. In this method, a fully mobile kiln was designed to produce Sarooj on the site. The kiln can produce 200 kg/h of Sarooj, and can be installed within one hour of arriving on the site. It can be towed by a tractor or a normal vehicle to the desired location, connected to the natural gas supply and the electric power. The construction is light, compact, and easy to start and shut down. In this paper, the plant is described in detail, together with some preliminary results of testing done on Sarooj produced by the kiln. Full details of tests on the product of the kiln will be given in a subsequent paper.

  18. Fiscal 1999 report on basic research for promotion of joint implementation programs. Basic research on Semipalatinsk, Republic of Kazakhstan, cement mill modernization; 1999 nendo Kazakhstan kyowakoku cement kojo kindaika kiso chosa hokokusho

    NONE

    2000-03-01

    This project aims to carry out the COP3 (Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change) protocol. In the clinker calcination sector, the wet kiln will be replaced by a dry NSP (new suspension preheater) kiln, and the existing four lines of material manufacturing facility and of clinker calcination facilities will be converted into single lines, respectively. Skills of the highest level will be applied to each of the facilities. The dry process will be dispensed with thanks to the dry kiln, which leads to drastic energy efficiency improvement. The change from ball mills to roller mills reduces electric power consumption. Energy reduction is expected to be 48,554 tons/year in oil at a saving rate of 39%. Greenhouse gas reduction is expected to be 216,960 tons/year in CO2 at a reduction rate of 28.5%. Provided that the construction cost is 98-million US dollars and the yield is 762-thousand tons, the internal rate of ROI (return on investment) will be 5.7% after tax (fully self-financed). ROE (return on equity) values are calculated under various borrowing conditions, and then it is found that the project will be feasible if a low interest loan with a long term of repayment is available. Since all the cement mills are obsolescent in the republic, the conversion of the present kilns into NSP type kilns will gain public favor. (NEDO)

  19. Volume loss as a tool to assess kiln drying of eucalyptus wood

    Batista,Djeison Cesar; Klitzke,Ricardo Jorge; Rocha,Márcio Pereira da; Muñiz,Graciela Inez Bolzon de; Batista,Tharcia Ribeiro

    2013-01-01

    In this study, we aimed to analyze the kiln drying quality of Eucalyptus grandis, Eucalyptus saligna and Eucalyptus dunnii woods with respect to volume loss. Wood from the three species was kiln dried together with the same drying schedule and conditions in a conventional-temperature pilot kiln. Three kinds of volume loss were evaluated: total - from saturated (initial) to machined (final) condition; shrinkage - from saturated to 10% moisture content; and machining - from 10% moisture content...

  20. Moessbauer Study of a Celtic Pottery-Making Kiln in Lower Bavaria

    Gebhard, R.; Guggenbichler, E.; Haeusler, W.; Riederer, J.; Schmotz, K.; Wagner, F. E.; Wagner, U.

    2004-01-01

    In 1995 a well preserved 3rd century BC Celtic kiln for pottery making was excavated at Schmiedorf in Lower Bavaria. The firing chamber and the flue plate of the kiln were preserved, whereas the dome was not found. We report on a study of material from this kiln by neutron activation analysis, thin-section microscopy, X-ray diffraction and Moessbauer spectroscopy, all performed with the aim to learn more about pottery-making procedures in Celtic times.

  1. Leaching from waste incineration bottom ashes treated in a rotary kiln

    Hyks, Jiri; Nesterov, Igor; Mogensen, Erhardt

    2011-01-01

    Leaching from municipal solid waste incineration bottom ash treated in a rotary kiln was quantified using a combination of lab-scale leaching experiments and geochemical modelling. Thermal treatment in the rotary kiln had no significant effect on the leaching of Al, Ba, Ca, Mg, Si, Sr, Zn, sulfate...... the thermal treatment. Overall, rotary kiln thermal treatment of bottom ashes can be recommended to reduce the leaching of Cu, Pb, Cl and DOC; however, increased leaching of Cr and Mo should be expected....

  2. Gasification of sulphate soap for the lime kiln

    Saviharju, Kari (Valtion Teknillinen Tutkimuskeskus, Espoo (Finland). Lab. of Fuel and Process Technology); Timonen, Tuomas (Finnish Energy Economy Association, Espoo (Finland). Finnish Recovery Boiler Committee)

    1993-01-01

    Sulphate soap is a by-product of pulp mills utilized as a raw material for the chemical industry. However, this results in an increase in sulphur input of several kilograms SO[sub 2] per ADt pulp into the mill. Another increasingly interesting alternative is to utilize soap in the lime kiln of the mill. This has a positive effect, in addition to sulphur problems, on the energy balance of the mill. The crucial problem is the high Na + K content of soap, from 4 to 8%, which can result in plugging of the lime kiln. The operational problems can be avoided by gasifying the soap and by separating the inorganic materials from the product gas before the kiln. This paper describes research work on the gasification of crude sulphate soap carried out at the Technical Research Centre of Finland (VTT) over the years 1991 and 1992. This work will be continued in 1993 by focusing on specified problems, after which commercial applications should be available. (author)

  3. Lignite chemical conversion in an indirect heat rotary kiln gasifier

    Hatzilyberis Kostas S.

    2006-01-01

    Full Text Available The results on the gasification of Greek lignite using two indirect heat (allothermal pilot rotary kiln gasifiers are reported in the present work. The development of this new reactor-gasifier concept intended for solid fuels chemical conversion exploits data and experience gained from the following two pilot plants. The first unit A (about 100 kg/h raw lignite demonstrated the production of a medium heating value gas (12-13 MJ/Nm3 with quite high DAF (dry ash free coal conversions, in an indirect heat rotary gasifier under mild temperature and pressure conditions. The second unit B is a small pilot size unit (about 10 kg/h raw lignite comprises an electrically heated rotary kiln, is an operation flexible and exhibits effective phase mixing and enhanced heat transfer characteristics. Greek lignite pyrolysis and gasification data were produced from experiments performed with pilot plant B and the results are compared with those of a theoretical model. The model assumes a scheme of three consecutive-partly parallel processes (i. e. drying, pyrolysis, and gasification and predicts DAF lignite conversion and gas composition in relatively good agreement with the pertinent experimental data typical of the rotary kiln gasifier performance. Pilot plant B is currently being employed in lime-enhanced gasification studies aiming at the production of hydrogen enriched synthesis gas. Presented herein are two typical gas compositions obtain from lignite gasification runs in the presence or not of lime. .

  4. Cement manufacture and the environment - Part I: Chemistry and technology

    Van Oss, H. G.; Padovani, A.C.

    2002-01-01

    Hydraulic (chiefly portland) cement is the binding agent in concrete and mortar and thus a key component of a country's construction sector. Concrete is arguably the most abundant of all manufactured solid materials. Portland cement is made primarily from finely ground clinker, which itself is composed dominantly of hydraulically active calcium silicate minerals formed through high-temperature burning of limestone and other materials in a kiln. This process requires approximately 1.7 tons of raw materials perton of clinker produced and yields about 1 ton of carbon dioxide (CO2) emissions, of which calcination of limestone and the combustion of fuels each contribute about half. The overall level of CO2 output makes the cement industry one of the top two manufacturing industry sources of greenhouse gases; however, in many countries, the cement industry's contribution is a small fraction of that from fossil fuel combustion by power plants and motor vehicles. The nature of clinker and the enormous heat requirements of its manufacture allow the cement industry to consume a wide variety of waste raw materials and fuels, thus providing the opportunity to apply key concepts of industrial ecology, most notably the closing of loops through the use of by-products of other industries (industrial symbiosis). In this article, the chemistry and technology of cement manufacture are summarized. In a forthcoming companion article (part II), some of the environmental challenges and opportunities facing the cement industry are described. Because of the size and scope of the U.S. cement industry, the analysis relies primarily on data and practices from the United States.

  5. Accurate quantitative XRD phase analysis of cement clinkers

    Kern, A.

    2002-01-01

    Full text: Knowledge about the absolute phase abundance in cement clinkers is a requirement for both, research and quality control. Traditionally, quantitative analysis of cement clinkers has been carried out by theoretical normative calculation from chemical analysis using the so-called Bogue method or by optical microscopy. Therefore chemical analysis, mostly performed by X-ray fluorescence (XRF), forms the basis of cement plan control by providing information for proportioning raw materials, adjusting kiln and burning conditions, as well as cement mill feed proportioning. In addition, XRF is of highest importance with respect to the environmentally relevant control of waste recovery raw materials and alternative fuels, as well as filters, plants and sewage. However, the performance of clinkers and cements is governed by the mineralogy and not the elemental composition, and the deficiencies and inherent errors of Bogue as well as microscopic point counting are well known. With XRD and Rietveld analysis a full quantitative analysis of cement clinkers can be performed providing detailed mineralogical information about the product. Until recently several disadvantages prevented the frequent application of the Rietveld method in the cement industry. As the measurement of a full pattern is required, extended measurement times made an integration of this method into existing automation environments difficult. In addition, several drawbacks of existing Rietveld software such as complexity, low performance and severe numerical instability were prohibitive for automated use. The latest developments of on-line instrumentation, as well as dedicated Rietveld software for quantitative phase analysis (TOPAS), now make a decisive breakthrough possible. TOPAS not only allows the analysis of extremely complex phase mixtures in the shortest time possible, but also a fully automated online phase analysis for production control and quality management, free of any human interaction

  6. Guidebook for Using the Tool BEST Cement: Benchmarking and Energy Savings Tool for the Cement Industry

    Galitsky, Christina; Price, Lynn; Zhou, Nan; Fuqiu , Zhou; Huawen, Xiong; Xuemin, Zeng; Lan, Wang

    2008-07-30

    The Benchmarking and Energy Savings Tool (BEST) Cement is a process-based tool based on commercially available efficiency technologies used anywhere in the world applicable to the cement industry. This version has been designed for use in China. No actual cement facility with every single efficiency measure included in the benchmark will likely exist; however, the benchmark sets a reasonable standard by which to compare for plants striving to be the best. The energy consumption of the benchmark facility differs due to differences in processing at a given cement facility. The tool accounts for most of these variables and allows the user to adapt the model to operational variables specific for his/her cement facility. Figure 1 shows the boundaries included in a plant modeled by BEST Cement. In order to model the benchmark, i.e., the most energy efficient cement facility, so that it represents a facility similar to the user's cement facility, the user is first required to input production variables in the input sheet (see Section 6 for more information on how to input variables). These variables allow the tool to estimate a benchmark facility that is similar to the user's cement plant, giving a better picture of the potential for that particular facility, rather than benchmarking against a generic one. The input variables required include the following: (1) the amount of raw materials used in tonnes per year (limestone, gypsum, clay minerals, iron ore, blast furnace slag, fly ash, slag from other industries, natural pozzolans, limestone powder (used post-clinker stage), municipal wastes and others); the amount of raw materials that are preblended (prehomogenized and proportioned) and crushed (in tonnes per year); (2) the amount of additives that are dried and ground (in tonnes per year); (3) the production of clinker (in tonnes per year) from each kiln by kiln type; (4) the amount of raw materials, coal and clinker that is ground by mill type (in tonnes per

  7. Colorectal cancer and non-malignant respiratory disease in asbestos cement and cement workers

    Jacobsson, K.

    1993-09-01

    Radiologically visible parenchymal changes (small opacities >= 1/0;ILO 1980 classification) were present in 20% of a sample of workers (N=174), employed for 20 years (median) in an asbestos cement plant. Exposure-response relationships were found, after controlling for age and smoking habits. In a sample of asbestos cement workers with symptoms and signs suggestive of pulmonary disease (N=33), increased lung density measured by x-ray computed tomography, and reduced static lung volumes and lung compliance was found. In a cohort of asbestos cement workers (N=1.929) with an estimated median exposure of 1.2 fibres/ml, the mortality from non-malignant respiratory disease was increased in comparison to a regional reference cohort (N=1.233). A two-to three-fold increase of non-malignant respiratory mortality was noted among workers employed for more than a decade in the asbestos cement plant, compared to cement workers (N=1.526), who in their turn did not experience and increased risk compared to the general population. In the cohorts of asbestos cement and cement workers, there was a tow-to three-fold increased incidence of cancer in the right part of the colon, compared to the general population as well as to external reference cohorts of other industrial workers (N=3.965) and fishermen (N=8.092). A causal relation with the exposure to mineral dust and fibres was supported by the findings of higher risk estimated in subgroups with high cumulated asbestos doses or longer duration of cement work. The incidence of cancer in the left part of the colon was not increased. Morbidity data, but not mortality data, disclosed the subsite-specific risk pattern. Both asbestos cement workers and cement workers has an increased incidence of rectal cancer, compared with the general population, and with the fishermen. The risk was, however, of the same magnitude among the other industrial workers. 181 refs

  8. Cometary Dust

    Levasseur-Regourd, Anny-Chantal; Agarwal, Jessica; Cottin, Hervé; Engrand, Cécile; Flynn, George; Fulle, Marco; Gombosi, Tamas; Langevin, Yves; Lasue, Jérémie; Mannel, Thurid; Merouane, Sihane; Poch, Olivier; Thomas, Nicolas; Westphal, Andrew

    2018-04-01

    This review presents our understanding of cometary dust at the end of 2017. For decades, insight about the dust ejected by nuclei of comets had stemmed from remote observations from Earth or Earth's orbit, and from flybys, including the samples of dust returned to Earth for laboratory studies by the Stardust return capsule. The long-duration Rosetta mission has recently provided a huge and unique amount of data, obtained using numerous instruments, including innovative dust instruments, over a wide range of distances from the Sun and from the nucleus. The diverse approaches available to study dust in comets, together with the related theoretical and experimental studies, provide evidence of the composition and physical properties of dust particles, e.g., the presence of a large fraction of carbon in macromolecules, and of aggregates on a wide range of scales. The results have opened vivid discussions on the variety of dust-release processes and on the diversity of dust properties in comets, as well as on the formation of cometary dust, and on its presence in the near-Earth interplanetary medium. These discussions stress the significance of future explorations as a way to decipher the formation and evolution of our Solar System.

  9. MECHANISMS GOVERNING TRANSIENTS FROM THE BATCH INCINERATION OF LIQUID WASTES IN ROTARY KILNS

    When "containerized" liquid wastes, bound on sorbents. are introduced into a rotary kiln in a batch mode, transient phenomena in-volving heat transfer into, and waste mass transfer out of, the sorbent can oromote the raoid release of waste vaoor into the kiln environment. This ra...

  10. Design and operation of a solarheated dry kiln for tropical latitudes

    Brian Bond; Omar Espinoza; Philip Araman

    2011-01-01

    Lumber is usually dried to a specific moisture content prior to further manufacturing or use. While lumber can be air-dried, the ambient humidity in most localities prevents the lumber from reaching the moisture content necessary for dimensional stability and use, especially for interior use. Solar kilns are an inexpensive alternative to conventional steam-heated kilns...

  11. Study on provenance of Ru porcelain in yanhedian kiln and official jun porcelain by EDXRF

    Li Guoxia; Guo Min; Zhao Weijuan; Sun Hongwei; Gao Zhengyao; Xie Jianzhong; Wen Chang; Wang Chuan; Li Rongwu; Guo Peiyu; Yang Dawei

    2010-01-01

    To understand the provenance relationship of Ru porcelain in Yanhedian kiln and official Jun porcelain , with energy dispersive x-ray fluorescence spectrometer (EDXRF) measured 56 Ru porcelain in Yanhedian kiln and official Jun porcelain samples of chemical composition of the main volume, analysis results show: Yanhedian kiln Ru porcelain bodies Al 2 O 3 average content Outpaces official Jun porcelain bodies, SiO 2 , K 2 O average below official Jun porcelain bodies; Yanhedian kiln Ru porcelain glazes Al 2 O 3 average content Outpaces official Jun porcelain glaze, SiO 2 , CaO average significantly lower than Jun glaze, two primary body and glaze on porcelain to chemical composition of the averages vary. A display of the peacekeeping two-dimensional scatter analysis supplies of official Jun porcelain bodies focused, Yanhedia kiln Ru porcelain bodies birth supplies comparatively, Jun and Yanhedian kiln Ru porcelain bodies material habitats near but not identical. The official Jun porcelain glazes origin focused, glaze formula changes less, and Yanhedia kiln Ru porcelain glazes origin and formula are scattered. Therefore, Yanhedian kiln Ru porcelain samples and the Official Jun porcelain samples can be commendably differentiated by EDXRF testing and chemical composition scatter analysis. (authors)

  12. Manual of design and installation of Forest Service water spray dry kiln

    L.V. Teesdale

    1920-01-01

    The best thing that can be said of any dry kiln is that when it is run by a properly informed operator the temperature, humidity, and circulation are constant and uniform. In an endeavor to produce a kiln in which each of these could be regulated independently of the others, the Forest Products Laboratory designed and developed the "Forest Service Humidity...

  13. Feasibility study on energy conservation and modernization of Darkhan Cement Company

    NONE

    2001-03-01

    For Darkhan Cement Co. in Mongolia, an investigational survey was made of possibilities of conserving energy and reducing greenhouse effect gas emission. The Darkhan Cement plant, the two production lines of which are of a wet long kiln system, has a production capacity of approximately 0.2 million t/y. In the project, one of the two kilns is to be converted to dry NSP kiln, and the following were to be adopted: covered-in storage space for raw materials, reclaimer, blending silo, automatic control system by computer, vertical mill, new air beam type grate cooler, etc. As a result of the study, after carrying out this technology improvement, the amount of energy conservation is 30,973 toe/y, and the amount of greenhouse effect gas reduction is 95,836 t-CO2/y. The total fund required for the project is approximately 3.082 billion yen, and the period of fund payback is 11 years after the start of the project. However, the necessary condition for realizing the project is the application of the preferential system such as the environment special yen credit, etc. (NEDO)

  14. Metals partitioning resulting from rotary kiln incineration of hazardous waste

    Richards, M.K.; Fournier, D.J. Jr.

    1992-01-01

    In response to the need for date on the partitioning of trace metals from hazardous waste incinerators, an extensive series of test was conducted in the summer of 1991 at the USEPA Incineration Research Facility (IRF) in Jefferson, Arkansas. These tests were conducted in the IRF's rotary kiln incinerator system (RKS) equipped with a pilot-scale Calvert Flux-Force/Condensation scrubber as the primary air pollution control system (APCS). The purpose of this test series was to extend the data base on trace metal partitioning and to investigate the effects of variations in incinerator operation on metal partitioning. Another objective was to evaluate the effectiveness of the scrubber for collecting flue gas metals. This series is a continuation of an ongoing IRF research program investigating trace metal partitioning and APCS collection efficiencies. Two previous test series were conducted using the RKS equipped with a venturi/packed-column scrubber and a single-state ionizing wet scrubber. The primary objective of this test series was to determine the fate of six hazardous and four nonhazardous trace metals fed to the RKS in a synthetic, organic-contaminated solid waste matrix. The six hazardous trace metals used were arsenic, barium, cadmium, chromium, mercury, and lead. The four nonhazardous trace metals--bismuth, copper, magnesium, and strontium--were included primarily to supply data to evaluate their potential for use as surrogates. The temperature, waste feed chlorine content, and scrubber pressure drop. The test program objectives were to identify. The partitioning of metals among kiln ash, scrubber liquor, and flue gas. Changes in metal partitioning related to variations in kiln exit gas temperature and waste feed chlorine content. The efficiency of the Calvert scrubber for collecting flue gas metals. The effects of scrubber pressure drop on metal collection efficiencies. 2 figs., 2 tabs

  15. Volume loss as a tool to assess kiln drying of eucalyptus wood

    Djeison Cesar Batista

    Full Text Available In this study, we aimed to analyze the kiln drying quality of Eucalyptus grandis, Eucalyptus saligna and Eucalyptus dunnii woods with respect to volume loss. Wood from the three species was kiln dried together with the same drying schedule and conditions in a conventional-temperature pilot kiln. Three kinds of volume loss were evaluated: total - from saturated (initial to machined (final condition; shrinkage - from saturated to 10% moisture content; and machining - from 10% moisture content to machined condition. Eucalyptus grandis wood was the most dimensionally stable and presented the smallest volume loss due to shrinkage. Although they had different shrinkage behaviors, Eucalyptus grandis and Eucalyptus saligna woods presented the same drying quality regarding machining and total volume losses. These species can be considered the same for kiln drying. Eucalyptus dunnii wood presented the worst quality in drying, and should not be kiln dried in the same batch with the other species.

  16. Effect of cement production on vegetation in a part of southwestern ...

    The impact of cement dust emissions from the factory of West African Portland Cement at Ewekoro in Southwestern Nigeria on the surrounding vegetation was investigated. Sample plots of 20 m x 20 m were established at 1 km intervals from the factory site up to a distance of 10 km intervals from the factory site up to a ...

  17. Allergies, asthma, and dust

    Reactive airway disease - dust; Bronchial asthma - dust; Triggers - dust ... Things that make allergies or asthma worse are called triggers. Dust is a common trigger. When your asthma or allergies become worse due to dust, you are ...

  18. Asphalt cement poisoning

    ... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

  19. Radioactivity of bone cement

    Scherer, M.A.; Winkler, R.; Ascherl, R.; Lenz, E.

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between [de

  20. Ultrafine portland cement performance

    C. Argiz

    2018-04-01

    Full Text Available By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

  1. Sulfur polymer cement concrete

    Weber, H.H.; McBee, W.C.

    1990-01-01

    Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

  2. Analysis of energy-efficiency opportunities for the cement industry in Shandong Province, China: A case study of 16 cement plants

    Hasanbeigi, Ali; Price, Lynn; Lu, Hongyou [China Energy Group, Energy Analysis Department, Environmental Energy Technologies Division, Ernest Orlando Lawrence Berkeley National Laboratory, 1 Cyclotron Road, MS 90R4000, Berkeley, CA 94720 (United States); Lan, Wang [China Building Materials Academy, Guanzhuang, Chaoyang District, Beijing, Post code 100024 (China)

    2010-08-15

    In this study, 16 cement plants with New Suspension Preheater and pre-calciner (NSP) kiln were surveyed. Plant energy use was compared to both domestic (Chinese) and international best practice using the Benchmarking and Energy Saving Tool for Cement (BEST-Cement). This benchmarking exercise indicated an average technical potential primary energy savings of 12% would be possible if the surveyed plants operated at domestic best practice levels in terms of energy use per ton of cement produced. Average technical potential primary energy savings of 23% would be realized if the plants operated at international best practice levels. Then, using the bottom-up Electricity Conservation Supply Curve (ECSC) model, the cost-effective electricity efficiency potential for the 16 studied cement plants in 2008 is estimated to be 373 gigawatt-hours (GWh), and total technical electricity-saving potential is 915 GWh, which accounts for 16 and 40% of total electricity use in the studied plants in 2008, respectively. The Fuel Conservation Supply Curve (FCSC) model shows the total technical fuel efficiency potential equal to 7949 terajoules (TJ), accounting for 8% of total fuel used in the studied cement plants in 2008. All the fuel efficiency potential is shown to be cost effective. (author)

  3. Development of a three-dimensional CFD model for rotary lime kilns

    Lixin Tao; Blom, Roger (FS Dynamics Sweden AB, Goeteborg (Sweden)); Nordgren, Daniel (Innventia, Stockholm (Sweden))

    2010-11-15

    In the calcium loop of the recovery cycle in a Kraft process of pulp and paper production, rotary lime kilns are used to convert the lime mud, mainly CaCO3, back to quick lime, CaO, for re-use in the causticizing process. The lime kilns are one of the major energy consumption devices for paper and pulp industry. Because of the rising oil price and new emission limits, the pulp mills have been forced to look for alternative fuels for their lime kilns. One interesting alternative to oil, often easily available at pulp mills, is biofuels such as sawdust and bark. However the practical kiln operation often encounters some difficulties because of the uncertainties around the biofuel impact on the lime kiln performance. A deeper understanding of the flame characteristics is required when shifting from oil to biofuels. Fortunately recent advances in modern Computational Fluid Dynamics, CFD, have provided the possibility to study and predict the detailed flame characteristics regarding the lime kiln performance. In this project a three-dimensional CFD model for rotary lime kilns has been developed. To simulate a rotary lime kiln the developed CFD model integrates the three essential sub-models, i.e. the freeboard hot flow model, the lime bed model and the rotating refractory wall model and it is developed based on the modern CFD package: FLUENT which is commercially available on the market. The numerical simulations using the developed CFD model have been performed for three selected kiln operations fired with three different fuel mixtures. The predicted results from the CFD modelling are presented and discussed in order to compare the impacts on the kiln performance due to the different firing conditions. During the development, the lime kiln at the Soedra Cell Moensteraas mill has been used as reference kiln. To validate the CFD model, in-plant measurements were carried out in the Moensteraas lime kiln during an experiment campaign. The results obtained from the

  4. ANALISIS EFISIENSI PANAS TUNNEL KILN PADA PT XYZ DENGAN NERACA MASSA DAN ENERGI

    Tri Ngudi Wiyatno

    2017-10-01

    ABSTRACT One of the process that can’t be missed to make a ceramic tile is burning. PT XYZusing tunnel kiln with LNG fuel for burning process. The purpose of this research is to know how much heat efficiency of tunnel kiln with firstly calculated mass balance and heat balance at burning ceramics tile. Data for incoming heat are obtain from calculated of heat burning fuel, sensible heat of LNG, incoming heat from kiln car and sensible heat green tile. Data for outgoing heat are obtain from calculated of sensible heat ceramic tile, sensible heat kiln car, evaporation heat of water and water crystal, heat loss because cooling air, heat of burning, heat for dryer, heat for chimney fan, and heat loss because heat transfer. The method that we used for this research are Consumption of Volume LNG, composition material tile, composition part of tunnel kiln like kiln car and heat capacity for each component. Based on the data we can obtained heat balance in and out kiln amount14.174.025 kkal/day. And the LNG fuel efficiencyis calculated by comparison between the heat generated from the fuel and the heat requirement used for one dayceramic tile burning process. After the calculation we can obtained the efficiencyis 98,92%. Keywords: Efficiency, Ceramic Tile, Mass Balance, Heat Balance, Burning.

  5. ULTRA-LIGHTWEIGHT CEMENT

    Fred Sabins

    2001-01-01

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter

  6. ULTRA-LIGHTWEIGHT CEMENT

    Fred Sabins

    2001-01-01

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

  7. The System of Simulation and Multi-objective Optimization for the Roller Kiln

    Huang, He; Chen, Xishen; Li, Wugang; Li, Zhuoqiu

    It is somewhat a difficult researching problem, to get the building parameters of the ceramic roller kiln simulation model. A system integrated of evolutionary algorithms (PSO, DE and DEPSO) and computational fluid dynamics (CFD), is proposed to solve the problem. And the temperature field uniformity and the environment disruption are studied in this paper. With the help of the efficient parallel calculation, the ceramic roller kiln temperature field uniformity and the NOx emissions field have been researched in the system at the same time. A multi-objective optimization example of the industrial roller kiln proves that the system is of excellent parameter exploration capability.

  8. Provenance and dating study on Jianyao Kiln porcelain bodies using NAA and WDXRF

    Feng Xiangqian; Feng Songlin; Li Jian'an; Li Dejin

    2007-01-01

    In order to distinguish provenance and age of Jianyao Kiln porcelains based on their chemical composition, 139 sherds that cover seven periods of production, were collected from three kiln sites. Trace and major elements in their body samples were determined by NAA and WDXRF, respectively. The analytical data and statistical analysis results show that all the body samples can be classified into 4 groups, i.e. Late Tang and Five Dynanties, Northern Song, Southern Song and Yuan. The raw materials adopted by Daluhoumen kiln site black porcelains were similar to those of Yingzhangqian site, but quite different from those of Anweishan site. (authors)

  9. Preparing hydraulic cement from oil-shale slag

    1921-11-19

    A process for the preparation of hydraulic cementing material from oil shale or oil-shale slag according to Patent 411,584 is characterized by the fact that the oil-shale slag is added to burnt marl, blast-furnace slag, and the like, whereupon the mixture is milled to dust in the known way.

  10. Preparation of hydraulic cement from oil-shale

    1921-08-28

    A process for the preparation of hydraulic cement from oil-shale or oil-shale residue is characterized in that, the oil-shale or shale-coke together with a slight amount of marl is burned under sintering conditions and the residue obtained is ground to a fine dust.

  11. A review on seashells ash as partial cement replacement

    Mohammad, Wan Ahmad Soffian Bin Wan; Hazurina Othman, Nor; Ibrahim, Mohd Haziman Wan; Rahim, Masazurah A.; Shahidan, Shahiron; Rahman, Raha Abd

    2017-11-01

    This review paper emphasis on various sea shells ash such as cockle, clam, oyster, mollusc, periwinkle, snail, and green mussel shell ash as partial cement replacement and its objective is to create sustainable environment and reduce problems of global warming. Cement production give huge impact to environment in every stage of its production. These include air pollution in form of dust and, gases, sound and vibration during quarry crushing and milling. One of the solutions to solve this problem is by using modified cement. The modified cement is a cementitious material that meets or exceeds the Portland cement performance by combining and optimizes the recycle and wasted materials. This will indirectly reduce the use of raw materials and then, become a sustain construction materials. Therefore, the replacement of cement in concrete by various sea shell ash may create tremendous saving of energy and also leads to important environmental benefits. This study includes previous investigation done on the properties of chemical and mechanical such as specific gravity, chemical composition, compressive strength, tensile strength and flexural strength of concrete produced using partial replacement of cement by seashells ash. Results show that the optimum percentage of seashells as cement replacement is between 4 - 5%.

  12. Fiscal 1999 international energy conservation model project. Report on result of demonstrative research concerning cement clinker cooling system; 1999 nendo kokusai energy shohi koritsuka nado model jigyo seika hokokusho. Cement clinker reikyaku sochi ni kakawaru jissho kenkyu

    NONE

    2000-03-01

    For the purpose of reducing energy consumption and CO2 discharge in a cement plant in Indonesia, R and D was conducted on new clinker cooling system, high performance kiln combustion system, and technology for steady kiln operation and control, with the fiscal 1999 results reported. In the research on the optimum clinker cooling system, a new type clinker cooling system (CCS) was developed in which air beams are applied only to stationary grate rows, in an air beam type clinker cooling system where cooling air is fed to each block, with grate plates used as the air duct. This year, in an actual machine testing equipment (capacity 2,500 t/d), the whole heat recuperation area was modified for the CCS, with the operation started since February, 1999, aiming at the optimal clinker cooling effect and high heat recovery efficiency. The heat quantity for the entire system showed a decrease of 60 kcal/kg in the heat consumption rate through CCS modification, kiln burner adjustment, etc. So long as the demonstration plant is concerned, design of a new type burner and study/design for the kiln stabilization were nearly completed. (NEDO)

  13. 41 CFR 50-204.50 - Gases, vapors, fumes, dusts, and mists.

    2010-07-01

    ... Soapstone 20 Talc 20 Portland cement 50 Graphite (natural) 15 Coat dust (respirable fraction less than 5% Si...-selector with the following characteristics: Aerodynamic diameter (unit density sphere) Percent passing...

  14. Impacts of cement industries on environment and control measure

    Hashmi, H.N.; Malik, H.N.; Naushad, Z.

    2005-01-01

    Utilization of cement as building material is gaining more importance. Cement industries around the world are contributing in global and as well as local pollution. In Pakistan most of the cement industries are constructed in remote areas without any proper environmental impact assessment. Unawareness of peoples toward sustainable environment and due to lack of job opportunities, dwellers are demanding employment rather than clean environment from title-holder of the industry. Air pollution caused by cement industries is harmful to the human's health, spoils and erodes building surface, corrodes metals, weakens textiles, deteriorates atmospheric visibility, affects plant life and leads to ecological imbalances. To investigate environmental impact of cement industries in Pakistan, environmental conditions around and inside the five cement industries in the vicinity of Taxila city are studied. To inspect the whole scenario, air pollution control devices in these industries were also examined in detail. These industries are using Electrostatic Precipitators and Baghouses to control air pollution (dust particulates). Proper caring of these equipment is necessary for better results. Detailed study shows that emissions from their stacks and dust particulates are causing problems. Health consultants in study area are much worry about the health of workers and environmental degradation in the vicinity of these industries. The comparison of air pollution control devices shows that Baghouses are environmental friendly. Considering the field conditions it is also concluded that involvement of government and environmental pollution control agencies is much more necessary. (author)

  15. The dissolution of natural and artificial dusts in glutamic acid

    Ling, Zhang; Faqin, Dong; Xiaochun, He

    2015-06-01

    This article describes the characteristics of natural dusts, industrial dusts, and artificial dusts, such as mineral phases, chemical components, morphological observation and size. Quartz and calcite are the main phases of natural dusts and industrial dusts with high SiO2 and CaO and low K2O and Na2O in the chemical composition. The dissolution and electrochemical action of dusts in glutamic acid liquor at the simulated human body temperature (37 °C) in 32 h was investigated. The potential harm that the dust could lead to in body glutamic acid acidic environment, namely biological activity, is of great importance for revealing the human toxicological mechanism. The changes of pH values and electric conductivity of suspension of those dusts were similar, increased slowly in the first 8 h, and then the pH values increased rapidly. The total amount of dissolved ions of K, Ca, Na, and Mg was 35.4 to 429 mg/kg, particularly Ca was maximal of 20 to 334 mg/kg. The total amount of dissolved ions of Fe, Zn, Mn, Pb, and Ba was 0.18 to 5.59 mg/kg and in Al and Si was 3.0 to 21.7 mg/kg. The relative solubility order of dusts in glutamic acid is wollastonite > serpentine > sepiolite, the cement plant industrial dusts > natural dusts > power plant industrial dusts. The wollastonite and cement plant industrial dusts have the highest solubility, which also have high content of CaO; this shows that there are a poorer corrosion-resisting ability and lower bio-resistibility. Sepiolite and power plant industrial dusts have lowest solubility, which also have high content of SiO2; this shows that there are a higher corrosion-resisting ability and stronger bio-resistibility.

  16. Study on Hongzhou kiln porcelains of successive dynasties by NAA

    Feng Xiangqian; Feng Songlin; Quan Kuishan

    2005-01-01

    400 sherds were collected from Hongzhou Kiln covering 8 periods from Eastern Han to Late Tang Dynasty/the Five Dynasties and their bodies were analysed by NAA. The results show that the elemental contents in different samples are quite distinct, even for those in the same period. It means no single element can be used as 'fingerprint' to distinguish the period. The curves of the contents of Na, Rb, Ba and Fe varying with time are very similar, like 'U' shape. As a colorant element, the content of Fe is consistent with the color of the body. The higher content of Fe is, the more dark of the body is. The outcome of principal component analysis (PCA) indicates that most of the sherds can be classified into 5 groups: (1) Eastern Han and Eastern Wu; (2) Western Jin, Eastern Jin and Southern Dynasties; (3) Sui; (4) Early Tang and Middle Tang; (5) Late Tang and Five Dynasties. (authors)

  17. Energy audit and conservation opportunities for pyroprocessing unit of a typical dry process cement plant

    Kabir, G.; Abubakar, A.I.; El-Nafaty, U.A.

    2010-01-01

    Cement production process has been highly energy and cost intensive. The cement plant requires 8784 h per year of the total operating hours to produce 640,809 tonnes of clinker. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed on the pyroprocessing unit of the cement plant. Fuel combustion generates the bulk of the thermal energy for the process, amounting to 95.48% (4164.02 kJ/kg cl ) of the total thermal energy input. Thermal efficiency of the unit stands at 41%, below 50-54% achieved in modern plants. The exhaust gases and kiln shell heat energy losses are in significant quantity, amounting to 27.9% and 11.97% of the total heat input respectively. To enhance the energy performance of the unit, heat losses conservation systems are considered. Waste heat recovery steam generator (WHRSG) and Secondary kiln shell were studied. Power and thermal energy savings of 42.88 MWh/year and 5.30 MW can be achieved respectively. Financial benefits for use of the conservation methods are substantial. Environmental benefit of 14.10% reduction in Greenhouse gases (GHG) emissions could be achieved.

  18. Energy audit and conservation opportunities for pyroprocessing unit of a typical dry process cement plant

    Kabir, G.; Abubakar, A.I.; El-Nafaty, U.A. [Chemical Engineering Programme, Abubakar Tafawa Balewa University, P. M. B. 0248, Bauchi (Nigeria)

    2010-03-15

    Cement production process has been highly energy and cost intensive. The cement plant requires 8784 h per year of the total operating hours to produce 640,809 tonnes of clinker. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed on the pyroprocessing unit of the cement plant. Fuel combustion generates the bulk of the thermal energy for the process, amounting to 95.48% (4164.02 kJ/kg{sub cl}) of the total thermal energy input. Thermal efficiency of the unit stands at 41%, below 50-54% achieved in modern plants. The exhaust gases and kiln shell heat energy losses are in significant quantity, amounting to 27.9% and 11.97% of the total heat input respectively. To enhance the energy performance of the unit, heat losses conservation systems are considered. Waste heat recovery steam generator (WHRSG) and Secondary kiln shell were studied. Power and thermal energy savings of 42.88 MWh/year and 5.30 MW can be achieved respectively. Financial benefits for use of the conservation methods are substantial. Environmental benefit of 14.10% reduction in Greenhouse gases (GHG) emissions could be achieved. (author)

  19. Development of a Metal Kiln for the Production of Charcoal from ...

    African Journal of Sustainable Development ... The study established that the design upon modification would be environmentally safe, viable and an economic alternative for ... Keywords: Production, Smoking, Charcoal, Kiln, Design ...

  20. Insulation performance data and assessment procedures for steam kiln energy conservation investments

    Zaccor, J.V.

    1980-09-01

    For a demonstration project, the costs and benefits of insulating concrete block curing kilns to isolate the kiln thermal mass from the curing cycle are determined. Data were developed on service life of FOAMGLAS insulation, the effect of Johnson burners on the insulation and mounting, performance of an alternative insulation (a rapidly installed, spray-on polyurethane foam), and a simple incentive to promote implementation of industrial energy conservation concepts. Data are tabulated and compared for the FOAMGLAS and CPR 480 polyurethane insulations. Specific studies of insulation that was installed on inside surfaces of kilns to lock the kiln-mass out of the curing cycle are given for Blocklite plant in California, the Ameron pipe plant in California, and the Superlite plant in Phoenix, Arizona. (MCW)

  1. Better lumber drying process with a non-greenhouse type solar kiln

    Yang, K C

    1979-01-01

    The preliminary study of using solar energy for lumber drying in NW Ontario is proven applicable and practical by the evidence of data collected. It was found that lumber seasoning using solar energy in the region is more favorable in the summer than in the winter. The most significant advantages of lumber drying with a solar kiln are: (1) low percentage of drying defect lumber produced; (2) higher strength properties of lumber produced; (3) unlimited sources of heat energy from the sun are available. The longer drying periods with a solar kiln as compared to a conventional steam kiln can be overcome by utilizing a supplemental heat system, e.g., wood residue burner to shorten the drying period. However, some improvements and modification of the existing kiln should be done in order to increase the efficiency of the lumber drying system.

  2. System of lower cogeneration in the cement industry; Sistema de cogeneracion inferior en la industria del cemento

    Romero Paredes, H.; Vazquez, A; Ambriz, J. J.; Fosado, A.; Cedillo, D.; Sanchez, R. [Universidad Autonoma Metropolitana-Iztapalapa (Mexico)

    1999-07-01

    In this paper present work, the design of a cogeneration system was made, taking advantage of the waste thermal flows in a cement manufacturing industry. The costs by concept of energy sources in the cement industry represent between 30 and 60% of the production costs, reason why any diminution in its consumption, will be reflected considerably in the productivity of the company. In order to determine the available capacity of waste energy and to establish the dimension of the cogeneration system it was decided to initially conduct balances of matter and energy of a cement production train. For the evaluation and numerical simulation a case study of a national plant was taken. The analysis takes only into account the rotary kiln, the pre roaster, the gas cooler or conditioner, the cooler of clinker and the separators or dust recuperators. In this study the electrical mills nor the systems that operate all over the plant have been taken in consideration. The results show that in general a high potential of co-generation exists since in some cases the heat losses can reach up to a 50% of the calorific energy input. The capacity of electrical generation by means of a steam turbine when taking advantage of a fraction (in the order of 60%) the residual heat, can be between 200 and 300 watts per kilogram of clinker produced. In conclusion, when recovering by means of appropriate heat exchangers for each one of the mentioned equipment the wasted energy and a network of heat interchange optimized by means of modern technologies an important part of the electrical energy that a cement mill uses can be generated. The method used has been very attractive and with the possibility of applying it to any cement mill and thus evaluate the potentials of energy co-generation. [Spanish] En el presente trabajo, se realizo el diseno de un sistema de cogeneracion aprovechando las corrientes termicas de desecho en una industria de fabricacion de cemento. Los costos por concepto de

  3. Evaluation of kiln-drying schedules for wild cherry wood (Cerasus avium)

    Korkut, Süleyman; Ünsal, Öner; Kocaefe, Duygu; Aytin, Ayhan; Gökyar, Asli

    2013-01-01

    Wild cherry wood (Cerasus avium (L.) Monench) lumber with a nominal thickness of 5 cm from Duzce region in Turkey was dried through conventional kiln drying using two different programs which are unprotective drying schedules, and protective drying schedules. The aim was to obtain the most desirable kiln schedule for keeping the wood quality at an appropriate level up to final moisture content of 12±2% was reached. Intensity of warping (twist, bow, cup, crook) occurrence, superficial, interna...

  4. Energy efficiency technologies in cement and steel industry

    Zanoli, Silvia Maria; Cocchioni, Francesco; Pepe, Crescenzo

    2018-02-01

    In this paper, Advanced Process Control strategies aimed at energy efficiency achievement and improvement in cement and steel industry are proposed. A flexible and smart control structure constituted by several functional modules and blocks has been developed. The designed control strategy is based on Model Predictive Control techniques, formulated on linear models. Two industrial control solutions have been developed, oriented to energy efficiency and process control improvement in cement industry clinker rotary kilns (clinker production phase) and in steel industry billets reheating furnaces. Tailored customization procedures for the design of ad hoc control systems have been executed, based on the specific needs and specifications of the analysed processes. The installation of the developed controllers on cement and steel plants produced significant benefits in terms of process control which resulted in working closer to the imposed operating limits. With respect to the previous control systems, based on local controllers and/or operators manual conduction, more profitable configurations of the crucial process variables have been provided.

  5. Dust and smoke pollution monitoring in industrial unit

    Shamsi, S.S.

    1995-01-01

    Dust and smoke are the two most commonly emitted industrial pollutants which are visible to the naked eye. Cement plants and power generation plants, based on coal and fuel oil etc. are the most common examples of industry emitting these pollutants. In this article these pollutants have been briefly described and some monitoring instruments for dust and smoke emissions have been specific. These instruments are especially suitable for power station and the cement industry etc. Automotive in urban areas. However, this paper does not include equipment for automotive exhaust pollution. (author)

  6. Basic survey project for Joint Implementation, etc. Feasibility study on the modernization of cement plant in Republic of Kazakhstan

    NONE

    2000-03-01

    For the purpose of reducing greenhouse effect gas emissions, a project was studied for the modernization of a cement plant in the Republic of Kazakhstan. In the Semipalatinsk cement plant, an old wet type kiln is being used which is much consuming in energy and low in productivity. By replacing this kiln with the NSP dry type kiln, expected were the enhancement of efficiency, energy conservation, and reduction in greenhouse effect gas emissions. Further, it was planned that four lines for raw material production and four lines for clinker combustion are tied together to make it one, and the ball mill is replaced with the low power-consuming type roller mill. By this project, the energy consumption will decrease by 96,000 t/y in coal and 2,095,500 kWh/y in electric power, which is a decrease of approximately 39% from the energy consumption before the project being worked out. Moreover, as to greenhouse effect gases, there are no changes in CO2 gas emissions from limestone, but CO2 gas emissions from coal decrease by 216.960 t/y, which is a decrease of 28.5% from that before the project being worked out. (NEDO)

  7. Controlled-air and rotary-kiln proof-of-principle tests

    Hedahl, T.G.

    1982-05-01

    Although the incinerator tests did not represent optimized processing, general system design characteristics were established. The test results indicated that the rotary kiln incinerator would be most applicable in the Transuranic Waste Treatment Facility (TWTF) for the following reasons: (1) The rotary kiln is more capable of achieving near-complete combustion of the combustibles in the waste mixed with a high proportion of metal and noncombustible waste. Complete combustion of the combustible waste is preferred in order to reduce waste volume and ensure the production of a stable, immobilized waste form. (2) The rotary kiln processing appears to be more flexible. Kiln rotation rate, kiln incline, and waste feed rate and method are system variables which can be altered to meet the needs of processing variable waste compositions. The advantages of the rotary kiln system allow for a practical concept for processing a majority of the radioactive waste at the INEL. However, further engineering tests must be performed to determine the necessary processing angles and design information for TWTF waste processing

  8. Numerical analysis of an entire ceramic kiln under actual operating conditions for the energy efficiency improvement.

    Milani, Massimo; Montorsi, Luca; Stefani, Matteo; Saponelli, Roberto; Lizzano, Maurizio

    2017-12-01

    The paper focuses on the analysis of an industrial ceramic kiln in order to improve the energy efficiency and thus the fuel consumption and the corresponding carbon dioxide emissions. A lumped and distributed parameter model of the entire system is constructed to simulate the performance of the kiln under actual operating conditions. The model is able to predict accurately the temperature distribution along the different modules of the kiln and the operation of the many natural gas burners employed to provide the required thermal power. Furthermore, the temperature of the tiles is also simulated so that the quality of the final product can be addressed by the modelling. Numerical results are validated against experimental measurements carried out on a real ceramic kiln during regular production operations. The developed numerical model demonstrates to be an efficient tool for the investigation of different design solutions for the kiln's components. In addition, a number of control strategies for the system working conditions can be simulated and compared in order to define the best trade off in terms of fuel consumption and product quality. In particular, the paper analyzes the effect of a new burner type characterized by internal heat recovery capability aimed at improving the energy efficiency of the ceramic kiln. The fuel saving and the relating reduction of carbon dioxide emissions resulted in the order of 10% when compared to the standard burner. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Energy consumption and CO2 emissions in China's cement industry: A perspective from LMDI decomposition analysis

    Xu Jinhua; Fleiter, Tobias; Eichhammer, Wolfgang; Fan Ying

    2012-01-01

    We analyze the change of energy consumption and CO 2 emissions in China's cement industry and its driving factors over the period 1990–2009 by applying a log-mean Divisia index (LMDI) method. It is based on the typical production process for clinker manufacturing and differentiates among four determining factors: cement output, clinker share, process structure and specific energy consumption per kiln type. The results show that the growth of cement output is the most important factor driving energy consumption up, while clinker share decline, structural shifts mainly drive energy consumption down (similar for CO 2 emissions). These efficiency improvements result from a number of policies which are transforming the entire cement industry towards international best practice including shutting down many older plants and raising the efficiency standards of cement plants. Still, the efficiency gains cannot compensate for the huge increase in cement production resulting from economic growth particularly in the infrastructure and construction sectors. Finally, scenario analysis shows that applying best available technology would result in an additional energy saving potential of 26% and a CO 2 mitigation potential of 33% compared to 2009. - Highlights: ► We analyze the energy consumption and CO 2 emissions in China's cement industry. ► The growth of cement output is the most important driving factor. ► The efficiency policies and industrial standards significantly narrowed the gap. ► Efficiency gains cannot compensate for the huge increase in cement production. ► The potentials of energy-saving of 26% and CO 2 mitigation of 33% exist based on BAT.

  10. Solid recovered fuels in the cement industry with special respect to hazardous waste.

    Thomanetz, Erwin

    2012-04-01

    Cements with good technical properties have been produced in Europe since the nineteenth century and are now worldwide standardized high-quality mass products with enormous production numbers. The basic component for cement is the so-called clinker which is produced mainly from raw meal (limestone plus clay plus sands) in a rotary kiln with preheater and progressively with integrated calciner, at temperatures up to 1450 °C. This process requires large amounts of fossil fuels and is CO₂-intensive. But most CO₂ is released by lime decomposition during the burning process. In the 1980s the use of alternative fuels began--firstly in the form of used oil and waste tyres and then increasingly by pre-conditioned materials from commercial waste and from high calorific industrial waste (i.e. solid recovered fuel (SRF))--as well as organic hazardous waste materials such as solvents, pre-conditioned with sawdust. Therefore the cement industry is more and more a competitor in the waste-to-energy market--be it for municipal waste or for hazardous waste, especially concerning waste incineration, but also for other co-incineration plants. There are still no binding EU rules identifying which types of SRF or hazardous waste could be incinerated in cement kilns, but there are some well-made country-specific 'positive lists', for example in Switzerland and Austria. Thus, for proper planning in the cement industry as well as in the waste management field, waste disposal routes should be considered properly, in order to avoid surplus capacities on one side and shortage on the other.

  11. Feasibility study on energy conservation through modernization of cement plant (Sichuan Double Horse Cement Group Co. Ltd.)

    NONE

    2001-03-01

    An investigational study was conducted of possibilities of energy conservation and greenhouse effect gas emission reduction in the cement production process of Double Horse Cement Co., Mianyang City, Sichuan Province, China. Double Horse Cement adopts the wet type long kiln production system and has a production ability of approximately 1.5 million t/y. In the project, as to three production lines out of the six production lines, improvement was planned to be made of the technologies on the following: mixing of raw materials, grinding of raw materials, NSP, clinker cooler, clinker pre-grinder, high-efficiency separator, waste heat use power generation, etc. As a result of the study, it was found that the energy conservation amount obtained was 54,646 toe/y. And, the amount of greenhouse effect gas reduction was 169,086 t-CO2/y. The total fund required for this project was approximately 5.553 billion yen and the internal earning rate was 7.36% after tax. When the project is carried out, expenses vs. effects are 9.8 toe/million yen in energy conservation amount and 30.4 t-CO2/million yen in greenhouse effect gas reduction. (NEDO)

  12. Download this PDF file

    ADOWIE PERE

    the dry density of soil sample shows that low comparative energy would be required for the soil to attain its maximum .... Conventional/Standard (BPF, 2015). Used. Standards ..... subgrade with cement kiln dust stabilization. Transp. Geotech 1: ...

  13. 40 CFR 264.314 - Special requirements for bulk and containerized liquids.

    2010-07-01

    ... rock; volcanic ash; cement kiln dust; fly ash; rice hull ash; activated charcoal/activated carbon); or (ii) High molecular weight synthetic polymers (e.g., polyethylene, high density polyethylene (HDPE...

  14. Study on the property of the production for Fengdongyan kiln in Early Ming dynasty by INAA and EDXRF

    Li, L.; Huang, Y.; Sun, H.Y.; Yan, L.T.; Feng, S.L.; Xu, Q.; Feng, X.Q.

    2016-01-01

    A lot of official wares carved “Guan” or the dragon patterns were excavated on the strata of Ming dynasty of the Fengdongyan kiln site at Dayao County. The imperial porcelain was fired in Hongwu and Yongle eras. However, the emergence of this imperial porcelain has triggered academic debate about the property of Fengdongyan kiln in the Early Ming dynasty. Based on the differences of the official kiln management, some scholars have determined that the property of the production for this kiln was the civilian kiln. According to the historical textural records and typology, others preliminary confirmed that Fengdongyan kiln was the official kiln. In this paper, the elemental compositions of body and glaze in imperial and civilian porcelain are study by INAA and EDXRF for determining the property of the production for this kiln in Early Ming dynasty. After the processing of experimental data by geochemical analysis and principal component analysis, the result show that the raw materials for making body and glaze in imperial porcelain are similar with those of the civilian porcelain and the degrees of elutriation for body can be slightly different in HW-M period of Ming dynasty. The analytical results support the view that the Fengdongyan kiln is civilian not official.

  15. Study on the property of the production for Fengdongyan kiln in Early Ming dynasty by INAA and EDXRF

    Li, L. [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China); Huang, Y.; Sun, H.Y. [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China); University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049 (China); Yan, L.T.; Feng, S.L.; Xu, Q. [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China); Feng, X.Q., E-mail: fengxq@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049 (China)

    2016-08-15

    A lot of official wares carved “Guan” or the dragon patterns were excavated on the strata of Ming dynasty of the Fengdongyan kiln site at Dayao County. The imperial porcelain was fired in Hongwu and Yongle eras. However, the emergence of this imperial porcelain has triggered academic debate about the property of Fengdongyan kiln in the Early Ming dynasty. Based on the differences of the official kiln management, some scholars have determined that the property of the production for this kiln was the civilian kiln. According to the historical textural records and typology, others preliminary confirmed that Fengdongyan kiln was the official kiln. In this paper, the elemental compositions of body and glaze in imperial and civilian porcelain are study by INAA and EDXRF for determining the property of the production for this kiln in Early Ming dynasty. After the processing of experimental data by geochemical analysis and principal component analysis, the result show that the raw materials for making body and glaze in imperial porcelain are similar with those of the civilian porcelain and the degrees of elutriation for body can be slightly different in HW-M period of Ming dynasty. The analytical results support the view that the Fengdongyan kiln is civilian not official.

  16. Advanced cementation concepts

    Howard, C.G.

    1989-10-01

    The purpose of this programme of work was to investigate whether improvements could be made to existing formulations for cement suitable for the immobilization of intermediate level radioactive waste. Two additives were selected, microsilica and limestone flour. Improvements to the cement were only slight. (author)

  17. Preparation of hydraulic cement

    1921-08-28

    A process for the preparation of hydraulic cement by the use of oil-shale residues is characterized in that the oil-shale refuse is mixed with granular basic blast-furnace slag and a small amount of portland cement and ground together.

  18. Low force cementation.

    Wilson, P R

    1996-07-01

    The marginal adaptation of full coverage restorations is adversely affected by the introduction of luting agents of various minimum film thicknesses during the cementation process. The increase in the marginal opening may have long-term detrimental effects on the health of both pulpal and periodontal tissues. The purpose of this study was to determine the effects of varying seating forces (2.5, 12.5, 25 N), venting, and cement types on post-cementation marginal elevation in cast crowns. A standardized cement space of 40 microns was provided between a machined gold crown and a stainless steel die. An occlusal vent was placed that could be opened or closed. The post-cementation crown elevation was measured, following the use of two commercially available capsulated dental cements (Phosphacap, and Ketac-cem Applicap). The results indicate that only the combination of Ketac-Cem Applicap and crown venting produced post-cementation crown elevation of less than 20 microns when 12.5 N seating force was used. Higher forces (25 N) and venting were required for comparable seating when using Phosphacap (19 microns). The amount of force required to allow maximum seating of cast crowns appears to be cement specific, and is reduced by effective venting procedures.

  19. Cementation process study

    Park, H.H.; Han, K.W.; Ahn, S.J.; Choi, K.S.; Lee, M.W.; Ryu, Y.K.

    1985-01-01

    In the cementation process study, in 1984, design of the waste treatment simulator was finished for the first step. We can experience not only the operation of solidification system but the design and construction of comming large scale plant through the design of cementation process. (Author)

  20. Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems

    Rabidin Zairul Amin

    2017-01-01

    Full Text Available Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be achieved in artificial drying kilns such as conventional kiln, dehumidification kiln, solar kiln, radio frequency-vacuum, etc. The objective of this study was to evaluate the characteristics of 30 mm and 50 mm thick kekatong (Cynometra spp. timber dried using kiln drying (KD and radio frequency-vacuum drying (RFV system. The investigation involved drying time, moisture content (MC variations between and within boards, drying defects, shrinkage, and drying stress. Drying defects include checks (surface, end, and internal checks and warping (bowing, cuping, spring, and twisting. The results showed that RFV drying time was reduced to 50% compared to the KD. RFV dried boards demonstrated a more uniform MC between and within boards. Shrinkage in width and thickness, as well as tangential/radial and volumetric shrinkages were substantially less in RFV boards. The amount of cupping, bowing and spring were very low and negligible in all drying runs. There was no twisting observed in all drying methods. The number of stress-free RFV board was higher than KD. With proper procedure, the RFV technology could be used for drying heavy hardwoods which are difficult to dry in conventional kilns due to excessive drying times and degradation.

  1. DOE mixed waste metals partition in a rotary kiln wet off-gas system

    Burns, D.B.; Looper, M.G.

    1994-01-01

    In 1996, the Savannah River Site plans to begin operation of the Consolidated Incineration Facility (CIF) to treat solid and liquid RCRA hazardous and mixed wastes. Test burns were conducted using surrogate CIF wastes spiked with hazardous metals and organics. The partition of metals between the kiln bottom ash, scrubber blowdown solution, and stack gas was measured as a function of kiln temperature, waste chloride content, and waste form (liquid or solid). Three waste simulants were used in these tests, a high and low chloride solid waste mix (paper, plastic, latex, PVC), and a liquid waste mix (benzene and chlorobenzene). An aqueous solution containing: antimony, arsenic, barium, cadmium, chromium, lead, mercury, nickel, silver, and thallium was added to the waste to determine metals fate under various combustion conditions. Test results were used to divide the metals into three general groups, volatile, semi-volatile, and nonvolatile metals. Mercury was the only volatile metal. No mercury remained in the kiln bottom ash under any incineration condition. Lead, cadmium, thallium, and silver exhibited semi-volatile behavior. The partition between the kiln ash, blowdown, and stack gas depended on incineration conditions. Chromium, nickel, barium, antimony, and arsenic exhibited nonvolatile behavior, with greater than 90 wt % of the metal remaining in the kiln bottom ash. Incineration temperature had a significant effect on the partition of volatile and semi-volatile metals, and no effect on nonvolatile metal partition. As incineration temperatures were increased, the fraction of metal leaving the kiln increased. Three metals, lead, cadmium, and mercury showed a relationship between chloride concentration in the waste and metals partition. Increasing the concentration of chlorides in the waste or burning liquid waste versus solid waste resulted in a larger fraction of metal exiting the kiln

  2. Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE-RBS

    Zhou, Z.; Zhang, K.; Xia, C. D.; Liu, M. T.; Zhu, J. J.; An, Z.; Bai, B.

    2015-03-01

    A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271-1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB6 crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907-960 A.D.) had been propagated to the Waguantan kiln site of Guizhou Province in the Yuan Dynasty.

  3. Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE–RBS

    Zhou, Z.; Zhang, K.; Xia, C.D.; Liu, M.T.; Zhu, J.J.; An, Z.; Bai, B.

    2015-01-01

    Highlights: •We analyzed 61 unearthed porcelain shards in Yuan Dynasty by PIXE–RBS. •An electron gun was installed to solve the electric charge accumulations. •The factor analysis was performed for the element compositions. •The “exotic group” porcelain samples unearthed were produced locally. -- Abstract: A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271–1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB 6 crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907–960 A.D.) had been

  4. Effect of Partial Replacement of Sand With Quarry Dust on the ...

    This work investigated the effect of partial replacement of sand with quarry dust on the compressive strength, flexural strength, split tensile strength and water absorption of sandcrete blocks. River sand was replaced with quarry dust at percentages ranging from 0 to 40 at cement/combined aggregate ratio of 1: 6. The blocks ...

  5. Suitability of iron ore tailings and quarry dust as fine aggregates for ...

    Eight concrete mixes were produced with different levels of sand replacement by either iron ore tailings or quarry dust, while the ninth mix of 100 % river sand served as the control. The highest 28-day compressive strength of 29.2 N/mm2 was obtained by blending 75 % sand and 25 % quarry dust with cement, which was 7 ...

  6. Gas phase dispersion in a small rotary kiln

    Spencer, B.B.

    1981-07-01

    A study was made of nonideal flow of gas in a rotary kiln reactor. A rotating tube 0.165 m in diameter by 2.17 m long, with internal lifting flights, was operated at room temperature. Rotational speeds from 2.0 to 7.0 rpm, air flow rates from 0.351 to 4.178 m 3 /h, and solid contents of 0.0, 5.1, and 15.3% of tube volume were studied. Residence time distribution of the gas was measured by means of the pulse injection technique using a helium tracer. A model was developed based on dispersive flow that exchanges with a deadwater region. Two parameters, a dispersion number describing bulk gas flow and an interchange factor describing exchange between the flow region and the gas trapped in the solids bed, were sufficient to correlate the data, but these parameters are sensitive to experimental error. The model is applicable to analysis of other flow systems, such as packed beds

  7. Study of meterial distribution of Tang tricolor from Huangye kiln

    Dong Junling; Zhao Weijuan; Liu Guodong; Cheng Huansheng; Liao Yongmin; Zhang Songlin

    2008-01-01

    By using the proton induced X-ray enission (PIXE) method, the measurements of the oxide compound content have veen carried out for the selected 18 samples of Tang tricolor in Huangye kiln. For ascertaining the classification and origin relation of the samples the principal component analysis method was adopted, and the results indicate that the chemical compositions of Tang tricolor body with diggerent glaze colors are close, which shows that their raw material habitat distribution is quite concentrative. But the prescriptions of diffierent color glaze are different. The content of CoO is more than others in blue glaze; CuO is more than others in green glaze; Fe 2 O 3 is more than others in brown and yellow glaze; A1 2 O3 is less than others but SiO 2 is more in white glaze, which shows that glazers material origin is diffierent, but brown and yellow glaze are close and even the same in chemistry component. (authors)

  8. Valorization of used tyres as fuel substitute in cement industry; Valorisation des pneus usages comme combustible de substitution en cimenterie

    Anon.

    1999-03-01

    According to the French syndicate of cement industry, more than 350000 t of worn tyres are produced each year in France, among which only 143000 t are reused in retreading, exported as used tyres or valorized in cement industry. The rest is generally tipped or burnt in the open-air. In cement kilns, the organic matters of tyres are completely burnt while the metal belts supply the necessary amount of iron to the cement composition. The combustion of tyres produces no black smoke, no smell and no ash and has no significant influence on the effluents of cement factories: gases are directly filtered in the kiln by the important mass of raw materials which acts as quicklime. In 1997, 31500 t of used tyres were burnt in the seven French cement factories over 34 that use this kind of fuel and represents 1.5% of the total energy needs. This substitution ratio could easily reach 10 to 15% without leading to any additional environmental or technical problem. A project of collection and valorization of used tyres has been developed by the French ministry of environment and aims at completely eliminating tyres tipping since July 1, 2002. In order to illustrate the French policy of tyres valorization, two examples of actions are presented in this paper: the first one is carried out by the Michelin manufacturer in order to facilitate the recycling of civil engineering tyres, and the second is carried out by Ciments d`Origny company at the Rochefort factory where tyres are used as fuel substitutes. (J.S.)

  9. Hydrogen fluoride damage to vegetation from peri-urban brick kilns in Asia: A growing but unrecognised problem?

    Ahmad, Muhammad Nauman; Berg, Leon J.L. van den; Shah, Hamid Ullah; Masood, Tariq; Büker, Patrick; Emberson, Lisa; Ashmore, Mike

    2012-01-01

    The rapid urbanisation of many cities in south and south-east Asia has increased the demand for bricks, which are typically supplied from brick kilns in peri-urban areas. We report visible foliar damage to mango, apricot and plum trees in the vicinity of traditional Bull’s Trench brick kilns in Peshawar, Pakistan. Visible injury symptoms, hydrogen fluoride concentrations in air, and foliar fluoride concentrations were all greater in the vicinity of brick kilns than at more distant sites, indicating that fluoride emissions from brick kilns were the main cause of damage. Interviews with local farmers established the significant impact of this damage on their livelihoods. Since poorly regulated brick kilns are often found close to important peri-urban agricultural areas, we suggest that this may be a growing but unrecognised environmental problem in regions of Asia where emission control in brick kilns has not been improved. - Highlights: ► Demand for bricks is increasing in many parts of Asia. ► Fluoride emissions from brick kilns may pose a threat to peri-urban agriculture. ► We found extensive injury to fruit orchards close to brick kilns in Peshawar. ► Local farmers suffered large economic losses but did not identify brick kilns as a cause of this. ► The extent of crop damage from brick kilns with poor emission control in the region may not be fully recognised. - Hydrogen fluoride emissions from brick kilns may cause extensive but unrecognised damage to peri-urban crops in Asia.

  10. Development of Portable Venturi Kiln for Agricultural Waste Utilization by Carbonization Process

    Agustina, S. E.; Chasanah, N.; Eris, A. P.

    2018-05-01

    Many types of kiln or carbonization equipment have been developed, but most of them were designed for big capacity and some also having low performance. This research aims to develop kiln, especially portable metal kiln, which has higher performance, more environmental- friendly, and can be used for several kinds of biomass or agricultural waste (not exclusive for one kind of biomass) as feeding material. To improve the kiln performance, a venturi drum type of portable kiln has been designed with an optimum capacity of 12.45 kg coconut shells. Basic idea of those design is heat flow improvement causing by venturi effect. The performance test for coconut shell carbonization shows that the carbonization process takes about 60-90 minutes to produce average yields of 23.8%., and the highest temperature of the process was 441 °C. The optimum performance has been achieved in the 4th test, which was producing 24% yield of highest charcoal quality (represented by LHV) in 65 minutes process at average temperature level 485 °C. For pecan shell and palm shell, design modification has been done by adding 6 air inlet holes and 3 ignition column to get better performance. While operation procedure should be modified on loading and air supply, depending on each biomass characteristic. The result of performance test showed that carbonization process of pecan shell produce 17 % yield, and palm shell produce 15% yield. Based on Indonesian Standard (SNI), all charcoal produced in those carbonization has good quality level.

  11. CFD modeling using PDF approach for investigating the flame length in rotary kilns

    Elattar, H. F.; Specht, E.; Fouda, A.; Bin-Mahfouz, Abdullah S.

    2016-12-01

    Numerical simulations using computational fluid dynamics (CFD) are performed to investigate the flame length characteristics in rotary kilns using probability density function (PDF) approach. A commercial CFD package (ANSYS-Fluent) is employed for this objective. A 2-D axisymmetric model is applied to study the effect of both operating and geometric parameters of rotary kiln on the characteristics of the flame length. Three types of gaseous fuel are used in the present work; methane (CH4), carbon monoxide (CO) and biogas (50 % CH4 + 50 % CO2). Preliminary comparison study of 2-D modeling outputs of free jet flames with available experimental data is carried out to choose and validate the proper turbulence model for the present numerical simulations. The results showed that the excess air number, diameter of kiln air entrance, radiation modeling consideration and fuel type have remarkable effects on the flame length characteristics. Numerical correlations for the rotary kiln flame length are presented in terms of the studied kiln operating and geometric parameters within acceptable error.

  12. Study on ancient porcelain of Loulinpo Kiln Site by nuclear analysis technology

    Wang, Y.Q.; Feng, S.L.; Feng, X.Q.; Lei, Y.; Cheng, L.; Xu, Q.; Zhou, Z.X.; Xue, D.X.

    2005-01-01

    Yaozhou Kiln located at Tongchuan of Shanxi Province has lasted continuous history of firing celadon porcelain from Tang Dynasty (618-907A.D.) to Yuan Dynasty (1234-1368A.D.), The firing technology has had important effect for celadon porcelain of many kilns in ancient China. In Jin Dynasty (1127-1234A.D.) and Yuan Dynasty, because of lacking of raw material resources, the central site of Yaozhou Kiln moved from Tongchuan to Lidipo, Shangdian and Chenlu area. Luolinpo site belongs to Yaozhou Kiln series and is one kiln of Shangdian area. The bowl sherds samples of Yuan dynasty stratum excavated in recent year. The glaze color is celadon, black, dark brown and dark reddish brown respectively. Ten pieces of sherds of each glaze color were selected. The main chemical compositions of theses samples were analyzed by XRF and the trace elemental contents were determined by NAA. The result shown that the content of Fe 2 O 3 can decide the kind of glaze color will be. The concentration of CaO, Na 2 O and K 2 O can be used to explain the developing process of firing techniques. Except samples of dark brown glaze, the contents of Fe 2 O 3 and CaO change in small range. The proportions of these main chemical compositions of the porcelain with glaze color of black, celadon and dark reddish brown have little variation. But it was very different form some samples of dark brown glaze.

  13. THE IMPACT OF BRICK KILN OPERATION TO THE DEGRADATION OF TOPSOIL QUALITY OF AGRICULTURAL LAND

    Md. Sirajul Islam

    2015-10-01

    Full Text Available Brick kiln is a big environmental issue for the agriculture of Bangladesh as it was observed that the agricultural production in the soil close to the brick kiln was lesser than the same soil far from brick kiln. The study was conducted to assess the impact of brick kiln operation to the degradation of topsoil quality at Singair of Kalihati upazila in Tangail, Bangladesh, during the period of July to December 2013. The Soil was collected from areas close to the brick fields and far from the brick fields at a depth of 0-15 cm. The Electrical Conductance (EC was found almost double in the soil samples close to the brick field than the soil samples far from brick field. The organic mattter content in the soil sample close to the brickfield was significantly lower than that of the far soil sample. The mean values of total N, available P and S were also significantly lower in the soil samples close to the brick kiln, 0.05%, 12.4, and 8.36 ppm respectively in the close soils, while 0.06%, 24.6, and 11.7 ppm respectively in the far soil. There were no significant changes observed in the other elements.

  14. COMPARISON BETWEEN WOOD DRYING DEFECT SCORES: SPECIMEN TESTING X ANALYSIS OF KILN-DRIED BOARDS

    Djeison Cesar Batista

    2015-04-01

    Full Text Available It is important to develop drying technologies for Eucalyptus grandis lumber, which is one of the most planted species of this genus in Brazil and plays an important role as raw material for the wood industry. The general aim of this work was to assess the conventional kiln drying of juvenile wood of three clones of Eucalyptus grandis. The specific aims were to compare the behavior between: i drying defects indicated by tests with wood specimens and conventional kiln-dried boards; and ii physical properties and the drying quality. Five 11-year-old trees of each clone were felled, and only flatsawn boards of the first log were used. Basic density and total shrinkage were determined, and the drying test with wood specimens at 100 °C was carried out. Kiln drying of boards was performed, and initial and final moisture content, moisture gradient in thickness, drying stresses and drying defects were assessed. The defect scoring method was used to verify the behavior between the defects detected by specimen testing and the defects detected in kiln-dried boards. As main results, the drying schedule was too severe for the wood, resulting in a high level of boards with defects. The behavior between the defects in the drying test with specimens and the defects of kiln-dried boards was different, there was no correspondence, according to the defect scoring method.

  15. The Development of the Clay Tobacco Pipe Kiln in the British Isles

    Allan Peacey

    1996-09-01

    Full Text Available In 1982 Allan Peacey published a study in the form of a synthesis of two chronologically separated kilns used in the production of clay tobacco pipes (Peacey 1982, 3-17. The aims of the present work are: ◦to improve upon this framework ◦to establish how these type of structures fit into the broader picture; to fill the gaps, before, between and after these cameo views ◦to improve understanding of the technology employed and see the roots from which such technology developed. The primary objective is to catalogue all relevant material know to exist in museum and private collections. It is hoped that by this means an understanding of the varied physical characteristics will lead to the establishment of object or function categories around which reports may be structured. Contemporary source documents are also examined to shed further light upon the likely function of the archaeological material. Among the results achieved are the compilation of an extensive catalogue of material associated with tobacco pipe kilns; the establishment of type series for pipe kiln furniture and furniture supplements; a proposed development sequence for pipe kiln muffles; a pattern of consistency in kiln design throughout the study area, and details of the methods used for stem tipping. Readers will be able to view the archaeological evidence as distribution maps, and will be able to explore other aspects of the data through the timeline and site catalogues.

  16. Energy efficiency improvement potentials for the cement industry in Ethiopia

    Tesema, Gudise; Worrell, Ernst

    2015-01-01

    The cement sector is one of the fast growing economic sectors in Ethiopia. In 2010, it consumed 7 PJ of primary energy. We evaluate the potential for energy savings and CO_2 emission reductions. We start by benchmarking the energy performance of 8 operating plants in 2010, and 12 plants under construction. The benchmarking shows that the energy intensity of local cement facilities is high, when compared to the international best practice, indicating a significant potential for energy efficiency improvement. The average electricity intensity and fuel intensity of the operating plants is 34% and 36% higher. For plants under construction, electricity use is 36% and fuel use 27% higher. We identified 26 energy efficiency measures. By constructing energy conservation supply curves, the energy-efficiency improvement potential is assessed. For the 8 operating plants in 2010, the cost-effective energy savings equal 11 GWh electricity and 1.2 PJ fuel, resulting in 0.1 Mt CO_2 emissions reduction. For the 20 cement plants expected to be in operation by 2020, the cost-effective energy saving potentials is 159 GWh for electricity and 7.2 PJ for fuel, reducing CO_2 emissions by about 0.6 Mt. We discuss key barriers and recommendations to realize energy savings. - Highlights: • The cement sector in Ethiopia is growing rapidly, using mainly imported fuels. • Benchmarking demonstrates a significant potential for energy efficiency improvement. • A large part of the energy efficiency potential can be achieved cost-effectively. • Ethiopia should ban the construction of obsolete vertical shaft kilns.

  17. Modified pavement cement concrete

    Botsman, L. N.; Ageeva, M. S.; Botsman, A. N.; Shapovalov, S. M.

    2018-03-01

    The paper suggests design principles of pavement cement concrete, which covers optimization of compositions and structures at the stage of mixture components selection due to the use of plasticizing agents and air-retaining substances that increase the viability of a concrete mixture. It also demonstrates advisability of using plasticizing agents together with air-retaining substances when developing pavement concrete compositions, which provides for the improvement of physical and mechanical properties of concrete and the reduction of cement binding agent consumption thus preserving strength indicators. The paper shows dependences of the main physical-mechanical parameters of concrete on cement consumption, a type and amount of additives.

  18. Radioactive waste cementation

    Soriano B, A.

    1996-01-01

    This research was carried out to develop the most adequate technique to immobilize low and medium-activity radioactive waste. different brands of national cement were used, portland and pozzolanic cement. Prismatic and cylindrical test tubes were prepared with different water/cement (W/C) relationship. Additives such a as clay and bentonite were added in some other cases. Later, the properties of these test tubes were evaluated. Properties such as: mechanical resistance, immersion resistance, lixiviation and porosity resistance. Cement with the highest mechanical resistance values, 62,29 MPa was pozzolanic cement for a W/C relationship of 0,35. It must be mentioned that the other types of cements reached a mechanical resistance over 10 MPa, a value indicated by the international standards for transportation and storage of low and medium-activity radioactive waste at a superficial level. However, in the case of immersion resistance, Sol cement (portland type I) with a W/C relationship of 0,35 reached a compression resistance over 61,92 MPa; as in the previous cases, the other cements reached a mechanical resistance > 10 MPa. Regarding porosity, working with W/C relationships = 0,35 0,40 and 0,45, without additives and with additives, the percentage of porosity found for all cements is lower than 40% percentage indicated by international standards. With regard to the lixiviation test, pozzolanic cement best retained Cesium-137 and Cobalt-60, and increased its advantages when bentonite was added, obtaining a lixiviation rate of 2,02 x E-6 cm/day. Sol cement also improved its properties when bentonite was added and obtained a lixiviation rate of 2,84 x E-6 cm/day for Cesium-137. However, Cobalt-60 is almost completely retained with the 3 types of cement with or without additives, reaching the limits indicated by the international standards for the lixiviation rate of beta-gamma emitter < 5,00E-4 cm/day. Characterizing the final product involves the knowledge of its

  19. Tympanoplasty with ionomeric cement

    Kjeldsen, A D; Grøntved, A M

    2000-01-01

    with isolated erosion of the long incus process have been treated with a new surgical technique in which the ossicular chain was rebuilt with ionomeric cement. The results in hearing performance (mean pure-tone average (PTA) 0.5, 1 and 2 kHz) were evaluated pre- and post-surgery, and compared to those...... of > 10 dB, in 4 there was a slight improvement and in 2 a decline. The difference was not statistically significant. Hearing improvement using ionomeric cement in type II tympanoplasty was satisfactory. Reconstruction of the ossicular chain with ionomeric cement is recommended, as the procedure is easy...

  20. Disposal of historically contaminated soil in the cement industry and the evaluation of environmental performance.

    Li, Yeqing; Zhang, Jiang; Miao, Wenjuan; Wang, Huanzhong; Wei, Mao

    2015-09-01

    Approximately 400000t of DDTs/HCHs-contaminated soil (CS) needed to be co-processed in a cement kiln with a time limitation of 2y. A new pre-processing facility with a "drying, grinding and DDTs/HCHs vaporizing" ability was equipped to meet the technical requirements for processing cement raw meal and the environmental standards for stack emissions. And the bottom of the precalciner with high temperatures >1000°C was chosen as the CS feeding point for co-processing, which has rarely been reported. To assess the environmental performance of CS pre- and co-processing technologies, according to the local regulation, a test burn was performed by independent and accredited institutes systematically for determination of the clinker quality, kiln stack gas emissions and destruction efficiency of the pollutant. The results demonstrated that the clinker was of high quality and not adversely affected by CS co-processing. Stack emissions were all below the limits set by Chinese standards. Particularly, PCDD/PCDF emissions ranged from 0.0023 to 0.0085ngI-TEQNm(-3). The less toxic OCDD was the peak congener for CS co-processing procedure, while the most toxic congeners (i.e. 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDD) remained in a minor proportion. Destruction and removal efficiency (DRE) and destruction efficiency (DE) of the kiln system were better than 99.9999% and 99.99%, respectively, at the highest CS feeding rate during normal production. To guarantee the environmental performance of the system the quarterly stack gas emission was also monitored during the whole period. And all of the results can meet the national standards requirements. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Leaching Behavior of Heavy Metals from Cement Pastes Using a Modified Toxicity Characteristic Leaching Procedure (TCLP).

    Huang, Minrui; Feng, Huajun; Shen, Dongsheng; Li, Na; Chen, Yingqiang; Shentu, Jiali

    2016-03-01

    As the standard toxicity characteristic leaching procedure (TCLP) can not exhaust the acid neutralizing capacity of the cement rotary kiln co-processing solid wastes products which is particularly important for the assessment of the leaching concentrations of heavy metals. A modified TCLP was proposed. The extent of leaching of heavy metals is low using the TCLP and the leaching performance of the different metals can not be differentiated. Using the modified TCLP, however, Zn leaching was negligible during the first 180 h and then sharply increased (2.86 ± 0.18 to 3.54 ± 0.26 mg/L) as the acidity increased (pH leaching is enhanced using the modified TCLP. While Pb leached readily during the first 126 h and then leachate concentrations decreased to below the analytical detection limit. To conclude, this modified TCLP is a more suitable method for these cement rotary kiln co-processing products.

  2. Feasibility study on energy conservation and modernization of Chhatak Cement Co., Ltd.

    NONE

    2001-03-01

    With an objective of saving energies and reducing greenhouse gas emission, discussions were given on a modernization plan for the Chhatak cement factory in The People's Republic of Bangladesh. The Chhatak cement factory having a nominal production capability of 267,000 tons a year uses mainly wet-type long kilns of old type, consuming a great amount of natural gas. The present plan has discussed adoption of the Japanese energy saving technologies. The technologies use a vertical roller mill for raw material pulverization, a suspension preheater and a short kiln for clinker sintering, a grate cooler for clinker cooling, and the pre-crushing system. The result of the discussions provided the prospects of reduction in the natural gas consumption at 50%, and reduction of electric power consumption at 16%. This will mean the annual reduction of about 22,000 tons as converted to crude oil. The CO2 reduction amount would reach 51,800 tons a year. The total investment amount would be US$37,327,000. The result of the financial analysis according to the case studies appears severe, wherein reduction of the various expenses is desired possibly by the finance from Japan with generous conditions.(NEDO)

  3. Feasibility study on effective use of energy in the cement manufacturing process

    NONE

    2001-03-01

    An investigational study was conducted of a project for energy conservation and greenhouse effect gas reduction by introducing the steam injection gas turbine generator to production facilities of the Siam Cement Industry Corporation (SCI) in Thailand. In the project, studies were made on the following: no purchases of electric power by introduction of the steam injection gas turbine generator; additional heating by gas turbine exhaust gas by introduction of the kiln combustion air heater; remodeling of the preheater of raw materials, and the partial calcination before kiln sintering by introduction of the calcination furnace. As a result of the study, the energy conservation amount was 1,200 toe/y, and the greenhouse effect gas reduction amount was approximately 8,000 t-CO2/y, which led to the reserve power for increased production of clinker by about 18%. The size of investment was 314.5 million Baht in total. As to the evaluation of economical efficiency of the investment, the actual period of ROI was a little less than 5 years, and the internal earning rate was 17.7%, which substantially met with SCI's standards for equipment investment. However, there are problems on the gas supply infrastructure, recovery of the white cement demand, etc. (NEDO)

  4. Feasibility study on energy conservation and modernization of Chhatak Cement Co., Ltd.

    NONE

    2001-03-01

    With an objective of saving energies and reducing greenhouse gas emission, discussions were given on a modernization plan for the Chhatak cement factory in The People's Republic of Bangladesh. The Chhatak cement factory having a nominal production capability of 267,000 tons a year uses mainly wet-type long kilns of old type, consuming a great amount of natural gas. The present plan has discussed adoption of the Japanese energy saving technologies. The technologies use a vertical roller mill for raw material pulverization, a suspension preheater and a short kiln for clinker sintering, a grate cooler for clinker cooling, and the pre-crushing system. The result of the discussions provided the prospects of reduction in the natural gas consumption at 50%, and reduction of electric power consumption at 16%. This will mean the annual reduction of about 22,000 tons as converted to crude oil. The CO2 reduction amount would reach 51,800 tons a year. The total investment amount would be US$37,327,000. The result of the financial analysis according to the case studies appears severe, wherein reduction of the various expenses is desired possibly by the finance from Japan with generous conditions.(NEDO)

  5. Feasibility study on effective use of energy in the cement manufacturing process

    NONE

    2001-03-01

    An investigational study was conducted of a project for energy conservation and greenhouse effect gas reduction by introducing the steam injection gas turbine generator to production facilities of the Siam Cement Industry Corporation (SCI) in Thailand. In the project, studies were made on the following: no purchases of electric power by introduction of the steam injection gas turbine generator; additional heating by gas turbine exhaust gas by introduction of the kiln combustion air heater; remodeling of the preheater of raw materials, and the partial calcination before kiln sintering by introduction of the calcination furnace. As a result of the study, the energy conservation amount was 1,200 toe/y, and the greenhouse effect gas reduction amount was approximately 8,000 t-CO2/y, which led to the reserve power for increased production of clinker by about 18%. The size of investment was 314.5 million Baht in total. As to the evaluation of economical efficiency of the investment, the actual period of ROI was a little less than 5 years, and the internal earning rate was 17.7%, which substantially met with SCI's standards for equipment investment. However, there are problems on the gas supply infrastructure, recovery of the white cement demand, etc. (NEDO)

  6. Method and Mechanisms of Soil Stabilization Using Electric Arc Furnace Dust

    Al-Amoudi, Omar S. Baghabra; Al-Homidy, Abdullah A.; Maslehuddin, Mohammed; Saleh, Tawfik A.

    2017-01-01

    This paper reports the method and mechanism for improving the strength of marl and desert sand utilizing electric arc furnace dust (EAFD), an industrial by-product, in lieu of cement or lime. EAFD was used in conjunction with a small quantity (2%) of cement. The mechanical properties and durability characteristics of marl and sand mixed with 2% cement plus 5-, 10-, 20- or 30%-EAFD, by weight of the soil, were evaluated. The soil-cement-EAFD mixtures were used to determine their unconfined com...

  7. A remote engineering solution for automating a roller hearth kiln

    João Bosco da Mota Alves

    2008-07-01

    Full Text Available Remote engineering (also known as online engineering may be defined as a combination of control engineering and telematics. In this area, specific activities require computacional skills in order to develop projects where electrical devives are monitored and / or controlled, in an intercative way, through a distributed network (e.g. Intranet or Internet. In our specific case, we will be dealing with an industrial plant. Within the last few years, there has been an increase in the number of activities related to remote engineering, which may be connected to the phenomenon of the large extension experienced by the Internet (e.g. bandwith, number of users, development tools, etc.. This increase opens new and future possibilities to the implementation of advance teleworking (or e-working positions. In this paper we present the architecture for a remote application, accessible through the Internet, able to monitor and control a roller hearth kiln, used in a ceramics industry for firing materials. The proposed architecture is based on a micro web server, whose main function is to monitor and control the firing process, by reading the data from a series of temperature sensors and by controlling a series of electronic valves and servo motors. This solution is also intended to be a low-cost alternative to other potential solutions. The temperature readings are obtained through K-type thermopairs and the gas flow is controlled through electrovalves. As the firing process should not be stopped before its complete end, the system is equipped with a safety device for that specific purpose. For better understanding the system to be automated and its operation we decided to develop a scale model (100:1 and experiment on it the devised solution, based on a Micro Web Server.

  8. [Chemical composition and chromaticity characteristic of Jilan glaze of Ming and Qing official kilns].

    Wu, Jun-ming; Zhang, Mao-lin; Li, Qi-jiang; Wu, Juan; Quan, Kui-shan; Cao, Jian-wen

    2012-08-01

    Color glazes of Ming and Qing official kilns are excellent representatives of the famous ancient Chinese porcelains. The study of official ware with Jilan glaze has been an important topic. But it made slow progress due to the rarity of samples with strict production management and using system. The recipes, chemical composition and chromaticity characteristic of the Jilan samples excavated from official kilns in the Ming and Qing dynasties were first discussed by systematical testing with the energy dispersive X-ray fluorescence (EDXRF) and color difference meter. The results showed that the porcelain stone content in Jilan bodies of official kiln in the Ming dynasty is higher than the samples of the Qing dynasty. The manganese content in Jilan glazes of the Ming dynasty is higher than that in the Qing dynasty, while the glaze ash addition and the lightness value in the glaze are opposite.

  9. Analysis of bluish-white porcelain of Fanchang kiln in Anhui province by INAA

    Yang Yuzhang; Zhang Juzhong

    2008-01-01

    The minor and trace elements in the bluish-white porcelain bodies of Fanchang kiln in different dynasties were determined by instrumental neutron activation analysis (INAA). Multivariable statistical analysis of the experimental data was carried out by SPSS software. The results show that the contents of Yb, Ta, Hf and Th varied notably between early and middle North Song Dynasty. The chemical compositions of Fanchang porcelain bodies can be divided into three groups corresponding to Five Dynasties, early Northern Song and middle Northern Song. Combined with the results of major elements analysis, we think that the raw materials of Fanchang kiln varied in different periods and the using up of fine raw materials was the main reason of Fanchang kiln's decline. (authors)

  10. Thermal decomposition of woody wastes contaminated with radioactive materials using externally-heated horizontal kiln

    Iwasaki, Toshiyuki; Kato, Shigeru; Yamasaki, Akihiro; Ito, Takuya; Suzuki, Seiichi; Kojima, Toshinori; Kodera, Yoichi; Hatta, Akimichi; Kikuzato, Masahiro

    2015-01-01

    Thermal decomposition experiments of woody wastes contaminated with radioactive materials were conducted using an externally-heated horizontal kiln in the work area for segregation of disaster wastes at Hirono Town, Futaba County, Fukushima Prefecture. Radioactivity was not detected in gaseous products of thermal decomposition at 923 K and 1123 K after passage through a trap filled with activated carbon. The contents of radioactive cesium ( 134 Cs and 137 Cs) were measured in the solid and liquid products of the thermal decomposition experiments and in the residues in the kiln after all of the experiments. Although a trace amount of radioactive cesium was found in the washing trap during the start-up period of operation at 923 K, most of the cesium remained in the char, including the residues in the kiln. These results suggest that most of the radioactive cesium is trapped in char particles and is not emitted in gaseous form. (author)

  11. CFD analysis of a rotary kiln using for plaster production and discussion of the effects of flue gas recirculation application

    Gürtürk, Mert; Oztop, Hakan F.; Pambudi, Nugroho Agung

    2018-04-01

    In this study, the CFD analysis of the rotary kiln is carried out for examining effects of various parameters on energy consumption and efficiency of the rotary kiln. The flue gas recirculation using in many applications is a useful method for combusting of fuel unburned in the flue gas. Also, effects of flue gas recirculation on the combusting of fuel, operating temperature and efficiency of the rotary kiln are discussed in this study. The rotary kiln, which is considered in this study, is used in plaster plant. Two different CFD models were created and these models are compared according to many parameters such as temperature distribution, mixture fraction, the mass fraction of O2, CO, CO and CH4 in the combustion chamber. It is found that the plaster plant has a great potential for an increase in energy efficiency. Results obtained for producers of rotary kiln and burner will be useful for determining better design parameters.

  12. the Danish cement industry

    la Cour, Lisbeth Funding; Møllgård, Peter

    2001-01-01

    We test econometrically whether the sole Danish producer of cement holds a dominant position in the Danish market for (grey) cement. In import penetration tests, we find that its pricing and quantity decisions are independent of import price and quantity, implying that it can act to a considerable extent independently of its competitors. We also test whether it can act independently of its customers and find that its demand is inelastic with respect to its price. It thus holds a dominant posi...

  13. The influence of petrography, mineralogy and chemistry on burnability and reactivity of quicklime produced in Twin Shaft Regenerative (TSR) kilns from Neoarchean limestone (Transvaal Supergroup, South Africa)

    Vola, Gabriele; Sarandrea, Luca; Della Porta, Giovanna; Cavallo, Alessandro; Jadoul, Flavio; Cruciani, Giuseppe

    2017-12-01

    This study evaluates the influence of chemical, mineralogical and petrographic features of the Neoarchean limestone from the Ouplaas Mine (Griqualand West, South Africa) on its burnability and quicklime reactivity, considering the main use as raw material for high-grade lime production in twin shaft regenerative (TSR) kilns. This limestone consists of laminated clotted peloidal micrite and fenestrate microbial boundstone with herringbone calcite and organic carbon (kerogen) within stylolites. Diagenetic modifications include hypidiotopic dolomite, micrite to microsparite recrystallization, stylolites, poikilotopic calcite, chert and saddle dolomite replacements. Burning and technical tests widely attest that the Neoarchean limestone is sensitive to high temperature, showing an unusual and drastically pronounced sintering or overburning tendency. The slaking reactivity, according to EN 459-2 is high for lime burnt at 1050 °C, but rapidly decreases for lime burnt at 1150 °C. The predominant micritic microbial textures, coupled with the organic carbon, are key-factors influencing the low burnability and the high sintering tendency. The presence of burial cementation, especially poikilotopic calcite, seems to promote higher burnability, either in terms of starting calcination temperature, or in terms of higher carbonate dissociation rate. In fact, the highest calcination velocity determined by thermal analysis is consistent with the highest slaking reactivity of the lower stratum of the quarry, enriched in poikilotopic calcite. Secondly, locally concentered dolomitic marly limestones, and sporadic back shales negatively affects the quicklime reactivity, as well. This study confirms that a multidisciplinary analytical approach is essential for selecting the best raw mix for achieving the highest lime reactivity in TSR kilns.

  14. Application of tracer technique in cement industry

    Baran'ai, L.

    1979-01-01

    Application is stated of the radioisotope indication method in the cement industry. The method was applied in three directions. In the first direction, by means of labelling of 300 steel mill balls by cobalt-60, wear of them was examined. The degree of wear of milling balls in the process of milling was determined according to the decrease of their weight. Radioactive label served only for tracing controll balls. In the second direction, according to the natural radioactivity being presented in ashes by radioisotopes radium-226 and thorium-229, amount of ashes in the products of cement milling was determined (in the mill product, cement product, flying dust and back loading groats). In the third direction, by means of labelling of definite fractions of mille by radioisotope gold-198, optimization of technological parameters of silos were raw meal is homogenization. The following technological parameters have been established: amount of homogenized material; time of homogenization and frequency of intensity changing of supplied compressed air jet [ru

  15. COMPARISON BETWEEN WOOD DRYING DEFECT SCORES: SPECIMEN TESTING X ANALYSIS OF KILN-DRIED BOARDS

    Djeison Cesar Batista; Márcio Pereira da Rocha; Ricardo Jorge Klitzke

    2015-01-01

    It is important to develop drying technologies for Eucalyptus grandis lumber, which is one of the most planted species of this genus in Brazil and plays an important role as raw material for the wood industry. The general aim of this work was to assess the conventional kiln drying of juvenile wood of three clones of Eucalyptus grandis. The specific aims were to compare the behavior between: i) drying defects indicated by tests with wood specimens and conventional kiln-dried boards; and ii) ph...

  16. Reducing firing of an early pottery making kiln at Batan Grande, Peru: A Moessbauer study

    Wagner, U.; Gebhard, R.; Haeusler, W.; Hutzelmann, T.; Riederer, J.; Shimada, I.; Sosa, J.; Wagner, F.E.

    1999-01-01

    Material from field firing experiments using a 2,700-year old Formative kiln at Batan Grande, Peru, was studied by X-ray diffraction and Moessbauer spectroscopy. The experiments explore the technology involved in producing the gray and black reduced ware for which Cupisnique and other Formative ceramics are justly known. During firing, the iron-bearing compounds in clays undergo characteristic changes which depend on kiln temperature and atmosphere. These changes can be observed in the Moessbauer spectra. By comparing spectra of an appropriate clay fired in field experiments and in the laboratory with the spectra of ancient ceramics, a description of Formative firing techniques in a reducing environment is attempted

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

    Ramirez, M.; Haber, R.

    1999-01-01

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

  18. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subse...

  19. Stone Dust Agglomeration for Utilizing as Building Material

    Gabriel Borowski

    2017-12-01

    Full Text Available In the paper we discuss the possibility of using stone dust for utilizing as building material. The tested material was amphibolite, found in the Sudeten Mountains and the Tatra Mountains in Poland. The chemical composition of dust was determined by means of spectrometry methods. Moreover, the basic physical properties of the material were designated. Stone dust was mixed with starch or cement binder. The binder addition was from 5% to 20% by weight. The water content was adjusted to about 25% humidity. The mixture was then compressed in a hydraulic press at 50 MPa. The results of the mechanical toughness of agglomerates were shown. On the basis of the results, acceptable toughness of agglomerates was found, with the addition of cement in mass share 20% and seasoning for 48 hours. However, starch was not suitable as a binder for agglomeration of amphibolite.

  20. The application of CFD modelling to support the reduction of CO2 emissions in cement industry

    Mikulčić, Hrvoje; Vujanović, Milan; Fidaros, Dimitris K.; Priesching, Peter; Minić, Ivica; Tatschl, Reinhard; Duić, Neven; Stefanović, Gordana

    2012-01-01

    The cement industry is one of the leading producers of anthropogenic greenhouse gases, of which CO 2 is the most significant. Recently, researchers have invested a considerable amount of time studying ways to improve energy consumption and pollutant formation in the overall cement manufacturing process. One idea involves dividing the calcination and clinkering processes into two separate furnaces. The calcination process is performed in a calciner while the clinkering process takes place in a rotary kiln. As this is new technology in the cement manufacturing process, calciners are still in the research and development phase. The purpose of this paper is to demonstrate the potential of CFD to support the design and optimization of calciners, whose use appears to be essential in reduction of CO 2 emission during cement production. The mathematical model of the calcination process was developed, validated and implemented into a commercial CFD code, which was then used for the analysis. From the results obtained by these simulations, researchers will gain an in-depth understanding of all thermo-chemical reactions in a calciner. This understanding can be used to optimize the calciner's geometry, to make production more efficient, to lower pollutant formation and to subsequently reduce greenhouse gas emissions. -- Highlights: ► The potential of CO 2 emissions reduction, by using a cement calciner was presented. ► When a cement calciner is used, CO 2 emissions reduction of 3–4% can be achieved. ► The calcination model was developed, validated, and then used for the analysis. ► Shown method can be applied for investigation and optimization of cement calciners.

  1. A new step in cement plant bypass technology; Une nouvelle avancee pour les by-pass en cimenterie

    Civiel, G. [Technip, 92 - Rueil-Malmaison (France)

    2001-12-01

    The demand of valorizing more and more waste fuel in cement industry results in an increase of volatile element quantities in kiln system, particularly chlorine. In 'Ciment, Betons, Platres, Chaux' no 849 May-June 2001, we made reference to the two new approaches developed by TECHNIP CL to solve the problem of the volatile elements in clinker burning lines: the raw meal curtain and the Taiheyo by-pass. The following article is focused on the second system. (author)

  2. Dust collector

    Sahourin, H.

    1988-03-22

    This invention relates to a dust collector or filter which may be used for large volume cleaning air for gases or for separating out industrial byproducts such as wood chips, sawdust, and shavings. It relies on filtration or separation using only a uniquely configured medium. A primary, but not exclusive, purpose of the invention is to enable very large throughput, capable of separating or filtering of gases containing up to three or more tons of byproduct with a minimum pressure-drop across the device. No preliminary cycloning, to remove major particulates is necessary. The collector generally comprises a continuous and integral filter medium which is suspended from a plurality of downwardly extending frames forming a series of separate elements having a triangular cross-section, each element being relatively wide at the top and narrow at the bottom to define, between adjacent elements, a divergent collecting space which is wide at the bottom. 11 figs.

  3. Dust Measurements in Tokamaks

    Rudakov, D; Yu, J; Boedo, J; Hollmann, E; Krasheninnikov, S; Moyer, R; Muller, S; Yu, A; Rosenberg, M; Smirnov, R; West, W; Boivin, R; Bray, B; Brooks, N; Hyatt, A; Wong, C; Fenstermacher, M; Groth, M; Lasnier, C; McLean, A; Stangeby, P; Ratynskaia, S; Roquemore, A; Skinner, C; Solomon, W M

    2008-01-01

    Dust production and accumulation impose safety and operational concerns for ITER. Diagnostics to monitor dust levels in the plasma as well as in-vessel dust inventory are currently being tested in a few tokamaks. Dust accumulation in ITER is likely to occur in hidden areas, e.g. between tiles and under divertor baffles. A novel electrostatic dust detector for monitoring dust in these regions has been developed and tested at PPPL. In DIII-D tokamak dust diagnostics include Mie scattering from Nd:YAG lasers, visible imaging, and spectroscopy. Laser scattering resolves size of particles between 0.16-1.6 (micro)m in diameter; the total dust content in the edge plasmas and trends in the dust production rates within this size range have been established. Individual dust particles are observed by visible imaging using fast-framing cameras, detecting dust particles of a few microns in diameter and larger. Dust velocities and trajectories can be determined in 2D with a single camera or 3D using multiple cameras, but determination of particle size is problematic. In order to calibrate diagnostics and benchmark dust dynamics modeling, pre-characterized carbon dust has been injected into the lower divertor of DIII-D. Injected dust is seen by cameras, and spectroscopic diagnostics observe an increase of carbon atomic, C2 dimer, and thermal continuum emissions from the injected dust. The latter observation can be used in the design of novel dust survey diagnostics

  4. High-resolution dating of ancient ceramic kilns in Thailand, Laos and Burma by radiocarbon and palaeomagnetism

    Barbetti, M.; Hein, D.

    1997-01-01

    Full text: Radiocarbon dating is widely used on organic samples, especially wood, charcoal and bone. Classical techniques use samples of several grams, but only a few milligrams is needed for measurements by Accelerator Mass Spectrometry (AMS). Palaeomagnetic techniques are readily applicable to the study of ancient kilns. Core samples are drilled from the walls and floors, and oriented before being detached and measured on a sensitive spinner magnetometer in a laboratory. Resolution of a quarter of a century at 95% confidence can be achieved in favourable circumstances but only at certain periods of time. Radiocarbon dating shows that the earliest stoneware ceramics are from the 11th - 12th centuries AD and palaeomagnetism indicates that many in-ground kilns are of this age. Kilns of this type, which were hollowed out in sediments near river banks or old terraces, are found near Sisatchanalai in north-central Thailand and near Luang Prabang in northern Laos; they are similar in age to the Khmer-type kilns found at Suphanburi in central Thailand. A different type of kiln, constructed of bricks and located above-ground, appears towards the end of the 13th century AD. One of the earliest surface kilns at Sisatchanalai has a well determined date of 1290 ± 15 AD (calibrated radiocarbon age, 95% confidence).There is an overlap of the two technologies; stratigraphy and palaeomagnetic results show that in-ground and above-ground brick kilns continue almost side-by-side throughout the 14th century AD. One of the latest in-ground kilns at Sisatchanalai has a date of 1410 ± 25 AD (calibrated radiocarbon age, 95% confidence). There are many brick kilns belonging to the l5th century AD at Sisatchanalai, and they appear then at other sites in north-central Thailand (e.g., Sukhothai and Phitsanulok) and in Burma (e.g., Lagumbyee). In-ground kilns continue to be used in northern Laos even in the 15th century AD. The latest brick kilns at Sisatchanalai are 16th and possibly 17th

  5. Cement for Oil Well Cementing Operations in Ghana

    Michael

    For Portland cement to qualify as oil well cement, the chemical and physical properties must meet ..... Reservoir Engineering, Stanford University,. Stanford, California, pp. ... Construction”, PhD Thesis, Kwame Nkrumah. University of Science ...

  6. ULTRA-LIGHTWEIGHT CEMENT

    Fred Sabins

    2001-10-23

    The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses tasks performed in the fourth quarter as well as the other three quarters of the past year. The subjects that were covered in previous reports and that are also discussed in this report include: Analysis of field laboratory data of active cement applications from three oil-well service companies; Preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; Summary of pertinent information from Russian ultra-lightweight cement literature review; and Comparison of compressive strengths of ULHS systems using ultrasonic and crush methods Results reported from the fourth quarter include laboratory testing of ULHS systems along with other lightweight cement systems--foamed and sodium silicate slurries. These comparison studies were completed for two different densities (10.0 and 11.5 lb/gal) and three different field application scenarios. Additional testing included the mechanical properties of ULHS systems and other lightweight systems. Studies were also performed to examine the effect that circulation by centrifugal pump during mixing has on breakage of ULHS.

  7. Energy efficiency of an innovative vertical axial rotary kiln for pottery production

    Carlos Andrés Forero Núñez

    2015-01-01

    Full Text Available Colombia is a remarkablecoal producer and exporter worldwide; several sectors use this resource for electricity and thermal energy production. Among them, the ceramic industry consumed 118,590 tons in 2011. Most of the pottery production companies in this country arelocated in rural areas and use old coal fired kilns with low energy efficiencies, generating environmental effects to the population nearby. Despite of the importance of these industries to the small rural economies, the government agencies have closed them due to the lack of development on cleaner devices. This work aims to analyze the thermal behavior of an innovative vertical axial rotary kiln for pottery production, and the energy efficiency varying operation mode. The kiln operated during seven hours needed three hours for stabilizing sintering temperature at 800°C. The mean temperatures of the loading, drying, sintering and cooling stage were 204°C, 223°C, 809°C and 321°C respectively. The convection and radiation heat losses were 15 % whereas the flue gas heat losses 18 %.During continuous operation, the kiln energy efficiency was about 60 %. This design proven to reach the temperatures required in the firing stage of the pottery production; moreover, a gas fuel was fuelled making the process cleaner and more efficient than coal-fired systems.

  8. CFD analysis of a full-scale ceramic kiln module under actual operating conditions

    Milani, Massimo; Montorsi, Luca; Stefani, Matteo; Venturelli, Matteo

    2017-11-01

    The paper focuses on the CFD analysis of a full-scale module of an industrial ceramic kiln under actual operating conditions. The multi-dimensional analysis includes the real geometry of a ceramic kiln module employed in the preheating and firing sections and investigates the heat transfer between the tiles and the burners' flame as well as the many components that comprise the module. Particular attention is devoted to the simulation of the convective flow field in the upper and lower chambers and to the effects of radiation on the different materials is addressed. The assessment of the radiation contribution to the tiles temperature is paramount to the improvement of the performance of the kiln in terms of energy efficiency and fuel consumption. The CFD analysis is combined to a lumped and distributed parameter model of the entire kiln in order to simulate the module behaviour at the boundaries under actual operating conditions. Finally, the CFD simulation is employed to address the effects of the module operating conditions on the tiles' temperature distribution in order to improve the temperature uniformity as well as to enhance the energy efficiency of the system and thus to reduce the fuel consumption.

  9. Pulmonary dysfunctions, oxidative stress and DNA damage in brick kiln workers.

    Kaushik, R; Khaliq, F; Subramaneyaan, M; Ahmed, R S

    2012-11-01

    Brick kilns in the suburban areas in developing countries pose a big threat to the environment and hence the health of their workers and people residing around them. The present study was planned to assess the lung functions, oxidative stress parameters and DNA damage in brick kiln workers. A total of 31 male subjects working in brick kiln, and 32 age, sex and socioeconomic status matched controls were included in the study. The lung volumes, capacities and flow rates, namely, forced expiratory volume in first second (FEV(1)), forced vital capacity (FVC), FEV(1)/FVC, expiratory reserve volume, inspiratory capacity (IC), maximal expiratory flow when 50% of FVC is remaining to be expired, maximum voluntary ventilation, peak expiratory flow rate and vital capacity were significantly decreased in the brick kiln workers. Increased oxidative stress as evidenced by increased malonedialdehyde levels and reduced glutathione content, glutathione S-transferase activity and ferric reducing ability of plasma were observed in the study group when compared with controls. Our results indicate a significant correlation between oxidative stress parameters and pulmonary dysfunction, which may be due to silica-induced oxidative stress and resulting lung damage.

  10. Palaeointensity determination on an early medieval kiln from Switzerland and the effect of cooling rate

    Donadini, F.; Kovacheva, M.; Kostadinova, M.; Hedley, I. G.; Pesonen, L. J.

    The archaeomagnetic intensity reference curve for Western Europe lacks data during the period from 600 to 1000 AD. Baked clay from the walls of a pottery kiln at Reinach (Switzerland), archaeologically dated to the beginning of the 9th century AD, and having a 14C date of 1250 ± 50 BP, was investigated in order to refine the ancient geomagnetic field intensity during this period. A previous study to test the suitability of the material has shown that the magnetic properties of the baked clay from this Reinach kiln are appropriate for an archaeomagnetic study, and furthermore an archaeomagnetic directional date agrees well with the 14C date. A series of palaeointensity measurements was carried out in Sofia (Bulgaria). Here we present the results obtained from the same material, as performed in Helsinki (Finland) using different techniques. The comparison of the results shows significant differences between the two datasets. Based on the literature data, the discrepancy can be explained in terms of the different cooling rates of the samples used during the experiments in the two laboratories. Nevertheless, the results show that the geomagnetic field intensity had a high mean value of 86.85 ± 1.49 μT when the kiln was last used. This observation is consistent with recent studies from France covering the period during which the Reinach kiln functioned.

  11. Provenance and indirect dating study on Hongzhou Kiln porcelains by INAA

    Feng, X.Q.; Feng, S.L.; Fan, C.S.; Zhang, W.J.; Quan, K.S.

    2005-01-01

    Hongzhou Kiln is one of the six leading celadon kilns in Tang Dynasty and plays an important role in the history of Chinese ceramics for its diverse decoration styles and innovative technology. Archaeologists divided Hongzhou Kiln production into 8 periods, i.e. Eastern Han and Eastern Wu, Western Jin, Eastern Jin, Southern Dynasties, Sui, Early Tang, Middle Tang, Late Tang and Five Dynasties. Up to now, 26 kiln sites have been discovered and excavated. A study on the chemical composition of the porcelains of different periods and provenance will help to know the developing process of Hongzhou celadon such as variation of raw materials, recipes, manufacturing technology, causes of prosperity and decline, etc. Over 200 sherds were collected and their body samples were analyzed by INAA. The compositional differences between samples with the same period but different provenance were observed. The contents of Na, Rb, Ba, Fe, Th, U, etc were found to be different among samples from different periods, which implies they may be used to identify the manufacturing age. The analytical data were further processed by principal component analysis (PCA). The statistical results show that all the sherds can be classified into 5 groups, (1) Eastern Han and Eastern Wu; (2) Western Jin, Eastern Jin and Southern Dynasties; (3) Sui; (4) Early Tang and Middle Tang; (5) Late Tang and Five Dynasties.

  12. Respiratory Abnormalities among Occupationally Exposed, Non-Smoking Brick Kiln Workers from Punjab, India.

    Tandon, Supriya; Gupta, Sharat; Singh, Sharanjeet; Kumar, Avnish

    2017-07-01

    Brick manufacturing industry is one of the oldest and fast-growing industries in India that employs a large section of people. Brick kiln workers are occupationally exposed to air pollutants. Nonetheless, only a few studies have so far been conducted on their respiratory health. To investigate the extent of respiratory impairment in brick kiln workers and to correlate it with the duration of exposure. A cross-sectional study was conducted. Spirometric parameters of 110 non-smoking male brick kiln workers aged 18-35 years in Patiala district, Punjab, India, were compared with an age-matched comparison group of 90 unexposed individuals. Brick kiln workers showed a significant (pworkers was associated with the duration of exposure. In workers with >8 years of exposure, the mean values of FEV 1 (1.92 L), FVC (2.01 L), FEF 25-75% (2.19 L/s) and PEFR (4.81 L/s) were significantly (pworkers with workers.

  13. Experimental and theoretical investigation on unburned coal char burnout in a pilot-scale rotary kiln

    Federico Cangialosi; Francesco Di Canio; Gianluca Intini; Michele Notarnicola; Lorenzo Liberti; Giulio Belz; Pompilio Caramuscio [Technical University of Bari, Taranto (Italy). Department of Environmental Engineering and Sustainable Development

    2006-11-15

    Oxidation reactivity studies are imperative for improving carbon re-burn technologies and valuing the heat content of unburned carbon within coal combustion ashes. Non-isothermal, thermal gravimetric analysis (TGA) was used to examine the oxidation kinetics of unburned carbon in coal combustion fly ashes having different particle size distributions; TGA results were related to combustion efficiencies as measured in a bench-scale rotary kiln. The activation energy and pre-exponential factor were determined for the chemically-controlled reaction regime; the transition temperatures between chemically-controlled and partially diffusion-controlled combustion regimes were obtained for unburned carbon particles of different sizes. After the oxidation reaction rates were evaluated, the residence time distribution (RTD) of fly ashes in the rotary kiln were experimentally measured and the mean residence times related to process parameters, including the rotating velocity and kiln inclination. By comparing these results with an advective-dispersive model, the axial dispersion coefficient of fly ashes was determined. The reaction rates obtained by thermal analyses and the RTDs were used to predict combustion efficiencies within the kiln and oxidation conditions of unburned carbon using various processing options. 21 refs., 6 figs., 4 tabs.

  14. PIV analysis of merging flow in a simplified model of a rotary kiln

    Larsson, I.A.S.; Granstroem, B.R.; Lundstroem, T.S. [Luleaa University of Technology, Division of Fluid and Experimental Mechanics, Luleaa (Sweden); Marjavaara, B.D. [LKAB, Kiruna (Sweden)

    2012-08-15

    Rotary kilns are used in a variety of industrial applications. The focus in this work is on characterizing the non-reacting, isothermal flow field in a rotary kiln used for iron ore pelletization. A downscaled, simplified model of the kiln is experimentally investigated using particle image velocimetry. Five different momentum flux ratios of the two inlet ducts to the kiln are investigated in order to evaluate its effect on the flow field in general and the recirculation zone in particular. Time-averaged and phase-averaged analyses are reported, and it is found that the flow field resembles that of two parallel merging jets, with the same characteristic flow zones. The back plate separating the inlet ducts acts as a bluff body to the flow and creates a region of reversed flow behind it. Due to the semicircular cross-section of the jets, the wake is elongated along the walls. Conclusions are that the flow field shows a dependence on momentum flux ratio of the jets; as the momentum flux ratio approaches unity, there is an increasing presence of von Karman-type coherent structures with a Strouhal number of between 0.16 and 0.18. These large-scale structures enhance the mixing of the jets and also affect the size of the recirculation zone. It is also shown that the inclination of the upper inlet duct leads to a decrease in length of the recirculation zone in certain cases. (orig.)

  15. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula.

  16. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

    Yu Li

    Full Text Available In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC, the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula.

  17. Assessment of macro and micro nutrients around brick kilns agricultural environment

    Abdul Halim Farhad Sikder

    2016-03-01

    Full Text Available Brick kiln is well known as one of the main sources of air pollution; however, the pollutants produced from it do not remain in the air, they ultimately fall down to the soil and pollute the surroundings, therefore, this study was carried out to assess the status of macro (N, P, K and S and micro nutrients (Fe, Mn and Zn, Cu in the agricultural environment near the brick kilns of Young Brahmaputra and Jamuna Floodplain soils. Composite soil and plant samples were collected from four distances such as 250 m, 500 m, 1000 m, and 1500 m in three different sites. Sulphur (2352–3378 mg kg−1, Zn (86–156 mg kg−1 and Cu (24.7–46.9 mg kg−1 are found in the elevated levels near brick kiln soils that is released due to burning of poor quality coal and fire woods. The alarming news is that plant uptake of S and micro nutrients in the nearest areas of the brick kilns are significantly higher than the areas far from the brick production and their concentration ranges from 23 mg kg−1 to 101 mg kg−1 for Zn, 10–41 mg kg−1 for Cu, 35–1309 mg kg−1 for Fe, 26–126 mg kg−1 for Mn and 2590–mg kg−1 for S. Data indicates both soil and plant received maximum amount of micronutrients and S concentrations within 500–1000 m distances from brick kilns. Iron and Mn concentrations vary within a permissible limit but the plant uptake is high. Nitrogen concentrations is increasing with the distance from the brick kilns in both soils and plants but no definite pattern of P and K accumulation was found. Research suggested avoiding agricultural practice nearby brick kiln soils due to micronutrient contamination in order to preserve adjoined agricultural environment.

  18. Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE–RBS

    Zhou, Z. [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064 (China); Zhang, K. [School of History and Culture, Sichuan University, Chengdu 610064 (China); Xia, C.D.; Liu, M.T.; Zhu, J.J. [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064 (China); An, Z., E-mail: anzhu@scu.edu.cn [Key Laboratory of Radiation Physics and Technology of Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064 (China); Bai, B., E-mail: baibin@scu.edu.cn [School of History and Culture, Sichuan University, Chengdu 610064 (China)

    2015-03-01

    Highlights: •We analyzed 61 unearthed porcelain shards in Yuan Dynasty by PIXE–RBS. •An electron gun was installed to solve the electric charge accumulations. •The factor analysis was performed for the element compositions. •The “exotic group” porcelain samples unearthed were produced locally. -- Abstract: A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271–1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB{sub 6} crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907–960 A.D.) had been

  19. Study of provenance properties on ancient porcelain of Yue Kiln at Si-long-kou with NAA

    Feng Songlin; Fan Dongyu; Feng Xiangqian; Cheng Lin; Lei Yong; Xu Qing; Quan Huishan; Shen Yueming; Zhou Zhexi; Zhang Wenjiang

    2005-01-01

    Chinese ancient porcelain history has lasted about three thousands years from Shang Dynasty (1100∼1600 BC). A large amount of ancient porcelain sherds with accuracy provenance and ages were excavated from a lot of kiln sites in China. Archaeologists and ceramic experts have recognized and researched it with excavated stratum, utensil shape, body quality, glaze color and painting pattern. However, the appearance characteristic of some ancient porcelain manufactured in different kilns is similar. Therefore, it is still difficult to identify the provenance and ages of the samples excavated from some sites using traditional methods. Up, to now, many problems of Chinese ancient porcelain are confused for archaeologist and collecting experts. The elemental composition of ancient porcelain shows certain information of provenance and age. Especially, the sorts and contents of the elements in porcelain didn't change, so it is very useful to determine the provenance of ancient porcelain with elemental composition characteristics. Provenance characteristic is the important scientific information to identify ancient porcelain wares excavated from sites and graves. The porcelain samples of Si-Long-Kou Yue kiln in Zhejiang Province of china have been analyzed with NAA in this paper. The provenance characteristic was compared with it of Hong-Zhou kiln of Jiang-Xi Province and Yao-Zhou kiln of Shan-Xi Province. The experimental data were studied with statistic methods. The results show that the chemical compositions of porcelain body samples for three kilns were different. The difference was been able identified. The porcelain body materials of both Si-Long-Kou Yue kiln and Hong-Zhou kiln of Jiang-Xi were similar. The samples of Yao-Zhou kiln in north of China existed obvious difference.

  20. Lung function reduction and chronic respiratory symptoms among workers in the cement industry: a follow up study

    Zeleke Zeyede K

    2011-11-01

    Full Text Available Abstract Background There are only a few follow-up studies of respiratory function among cement workers. The main aims of this study were to measure total dust exposure, to examine chronic respiratory symptoms and changes in lung function among cement factory workers and controls that were followed for one year. Methods The study was conducted in two cement factories in Ethiopia. Totally, 262 personal measurements of total dust among 105 randomly selected workers were performed. Samples of total dust were collected on 37-mm cellulose acetate filters placed in closed faced Millipore-cassettes. Totally 127 workers; 56 cleaners, 44 cement production workers and 27 controls were randomly selected from two factories and examined for lung function and interviewed for chronic respiratory symptoms in 2009. Of these, 91 workers; 38 cement cleaners (mean age 32 years, 33 cement production workers (36 years and 20 controls (38 years were examined with the same measurements in 2010. Results Total geometric mean dust exposure among cleaners was 432 mg/m3. The fraction of samples exceeding the Threshold Limit Value (TLV of 10 mg/m3 for the cleaners varied from 84-97% in the four departments. The levels were considerably lower among the production workers (GM = 8.2 mg/m3, but still 48% exceeded 10 mg/m3. The prevalence of all the chronic respiratory symptoms among both cleaners and production workers was significantly higher than among the controls. Forced Expiratory Volume in one second (FEV1 and FEV1/Forced Vital Capacity (FEV1/FVC were significantly reduced from 2009 to 2010 among the cleaners (p Conclusions The high prevalence of chronic respiratory symptoms and reduction in lung function is probably associated with high cement dust exposure. Preventive measures are needed to reduce the dust exposure.

  1. Modeling of Installations with a Rotary Kiln for Thermal Decontamination of Wastes

    Krot O.P.

    2018-04-01

    Full Text Available The object of the study is a plant for incineration of solid wastes in a rotary kiln with an afterburning chamber and thermal catalytic emission purification. The aim of the study was to determine the rational layout of the solid wastes loading system and the location of the burner during combustion in the system - a rotary kiln and an afterburning chamber. The results of simulation countercurrent and concurrent gas flow and wastes in the form of temperature gradients in the rotary kiln and afterburner chamber are presented. It is found that in the initial part of the rotary kiln, a temperature of more than 1000 °C is created on its lower surface, almost one-third of the length of the furnace (2.5-3 times more than in the concurrent mode. In a zone close to unloading, the temperature is minimal (less than 100 °C, therefore, the slag does not tolerate heat from the furnace, it has time to cool down. Criteria for the efficiency of the rotary kiln have been proposed: the length of the section where the maximum combustion temperature is reached, the length of the section before discharge of the slag, the temperature of the slag. A more efficient configuration for all the criteria is one that ensures the counter movement of debris and gas. To effectively use the volume of the afterburner chamber, the burners must be located at the maximum distance from each other. The outlet flue must also be as far from the burners as possible.

  2. Mini-cusab kiln for rapid small-scale manufacture of charcoal from scrub, coconut wood and coconut shells

    Little, E C.S.

    1978-05-01

    Following the development and operation of the mini-cusab kiln in New Zealand, FAO tested it successfully in the South Pacific where there is a glut of coconut wood, which has a very high moisture content. It is based on a 44 gallon drum and its construction and subsequent operation are described. It is designed to be supplied continuously with fuel until full of charcoal. The kilns have air ducts which are sealed with plugs as the level of charcoal formed by the continuous fueling rises within the kiln.

  3. Concrete = aggregate, cement, water?

    Jelinek, J.

    1990-01-01

    Concrete for the Temelin nuclear power plant is produced to about 70 different formulae. For quality production, homogeneous properties of aggregates, accurate proportioning devices, technological discipline and systematic inspections and tests should be assured. The results are reported of measuring compression strength after 28 days for different concrete samples. The results of such tests allow reducing the proportion of cement, which brings about considerable savings. Reduction in cement quantities can also be achieved by adding ash to the concrete mixes. Ligoplast, a plasticizer addition is used for improving workability. (M.D). 8 figs

  4. Technology Roadmaps: Cement

    NONE

    2009-07-01

    To support its roadmap work focusing on key technologies for emissions reductions, the International Energy Agency (IEA) also investigated one particular industry: cement. Cement production includes technologies that are both specific to this industry and those that are shared with other industries (e.g., grinding, fuel preparation, combustion, crushing, transport). An industry specific roadmap provides an effective mechanism to bring together several technology options. It outlines the potential for technological advancement for emissions reductions in one industry, as well as potential cross-industry collaboration.

  5. Exergetic life cycle assessment of cement production process with waste heat power generation

    Sui, Xiuwen; Zhang, Yun; Shao, Shuai; Zhang, Shushen

    2014-01-01

    Highlights: • Exergetic life cycle assessment was performed for the cement production process. • Each system’s efficiency before and after waste heat power generation was analyzed. • The waste heat power generation improved the efficiency of each production system. • It provided technical support for the implementation of energy-saving schemes. - Abstract: The cement industry is an industry that consumes a considerable quantity of resources and energy and has a very large influence on the efficient use of global resources and energy. In this study, exergetic life cycle assessment is performed for the cement production process, and the energy efficiency and exergy efficiency of each system before and after waste heat power generation is investigated. The study indicates that, before carrying out a waste heat power generation project, the objective energy efficiencies of the raw material preparation system, pulverized coal preparation system and rotary kiln system are 39.4%, 10.8% and 50.2%, respectively, and the objective exergy efficiencies are 4.5%, 1.4% and 33.7%, respectively; after carrying out a waste heat power generation project, the objective energy efficiencies are 45.8%, 15.5% and 55.1%, respectively, and the objective exergy efficiencies are 7.8%, 2.8% and 38.1%, respectively. The waste heat power generation project can recover 3.7% of the total input exergy of a rotary kiln system and improve the objective exergy efficiencies of the above three systems. The study can identify degree of resource and energy utilization and the energy-saving effect of a waste heat power generation project on each system, and provide technical support for managers in the implementation of energy-saving schemes

  6. Cement Mason's Curriculum. Instructional Units.

    Hendirx, Laborn J.; Patton, Bob

    To assist cement mason instructors in providing comprehensive instruction to their students, this curriculum guide treats both the skills and information necessary for cement masons in commercial and industrial construction. Ten sections are included, as follow: related information, covering orientation, safety, the history of cement, and applying…

  7. Cementation of liquid radioactive waste

    Efremenkov, V.

    2004-01-01

    The cementation methods for immobilisation of radioactive wastes are discussed in terms of methodology, chemistry and properties of the different types of cements as well as the worldwide experience in this field. Two facilities for cementation - DEWA and MOWA - are described in details

  8. Cementing a wellbore using cementing material encapsulated in a shell

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

    2016-08-16

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  9. Cementing a wellbore using cementing material encapsulated in a shell

    Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

    2017-03-14

    A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

  10. The mechanical effect of the existing cement mantle on the in-cement femoral revision.

    Keeling, Parnell

    2012-08-01

    Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

  11. Role of Substrate on Quartz Cementation in Quartz Aggregates

    Farver, J. R.; Winslow, D.; Onasch, C.

    2010-12-01

    Quartz cementation in quartz aggregates has been experimentally investigated. The starting material was disaggregated detrital quartz grains from the well-sorted, mature St. Peter Sandstone. The ‘as-is’ grains have patches of iron oxide coatings and some have euhedral overgrowths that contain iron oxide dust rims. In addition a set of experiments was run using grains that were cleaned by soaking in sodium hydrosulfite and sodium bisulfate solutions to remove exposed iron oxide coatings. Experimental charges consisted of amorphous silica powder (≈30 mg) to provide a source of silica for the quartz cement, AlCl3 powder (≈3 mg) to provide a tracer for Cathodoluminescence (CL) identification of cement formed during the experiment, 25 wt% NaCl brine solution (≈25 mg) to increase the silica solubility and to better mimic oil field brines, and the natural quartz grains (100-130 mg). The charges were weld-sealed in Au capsules and run in cold-seal pressure vessels at 250°C to 450°C at 150 MPa confining pressure for up to 8 weeks. After the experiments, the samples were vacuum impregnated with a low viscosity epoxy containing a blue dye. After curing, the sample charge was sawn in half along its long axis and one half was polished (to 1 micron diamond paste) for analysis. The nature and amount of quartz cement in the samples were determined by a combination of CL, light microscopy, and scanning electron microscopy. Photomosaics of the samples were created and the amount of cement, porosity, and average grain sizes were determined by point-counting. The cement formed during the experiment was easily recognized from the quartz grains (and previous overgrowths) by the difference in luminescence. The results indicate the amorphous silica powder provides a ready source for silica for quartz cementation due to its greater solubility than the quartz. The cementation rates are rapid (>14% cement formed in 2 weeks at 450°C and >7% in 8 weeks at 250°C). Compared to

  12. Possibilities of Pelletizing and Briquetting of Dusts from Castings Grinding

    A. Pribulová

    2010-04-01

    Full Text Available Foundry dust can be divided into three groups: metallic dust with Fe content over 70%, mixed dust with Fe or SiO2 content between 10 –70% and sand wastes with minimum content of SiO2 about 70%. Dust from castings grinding with high Fe content (87.9% is still landfillin Slovakia. The aim of experiments with dust from grinding has been to find the cheapest way of dust agglomeration with minimumamount of binder because of melting in the electric induction furnace. The dust was pelletized and briquetted and as binders bentonite, water glass and cement were used. Briquettes made from dust from grinding with addition of water glass got compression strength after three months on the air about 82 kPa. Briquettes with addition of water glass were melted together with cast iron in electric induction furnace. Yield of metal from briquettes was around 80% and slag quantity around 4% (without briquettes the slag quantity was 1.4%.

  13. Suitability of alumina cements for the cementation of boreholes under corrosive conditions, especially at the press fitting of CO{sub 2}; Eignung von Tonerdezementen fuer die Bohrlochzementierung unter korrosiven Bedingungen, insbesondere bei CO{sub 2}-Einpressung. Literaturstudie

    Plank, J.; Sieber, R. (comps.) [Technische Univ. Muenchen (Germany). Lehrstuhl fuer Bauchemie

    2011-07-15

    Calcium aluminate cements, also called aluminate cements, are special cements based on calcium aluminates. In construction (especially in dry-mix mortars), they are valued for their remarkably higher acid and corrosion resistance compared to Portland cement. Their high temperature resistance especially qualifies them for refractory cements which are used e.g. as liners in cement rotary kilns. The worldwide production of calcium aluminate cements adds up to about 3 million tons. In oil well cementing, calcium aluminate cements have first been used at the beginning of the 90ies, in fact initially for geothermal wells. Applications in permafrost soils as well as fire-flooding wells came later. The reason for the use in geothermal wells. Applications in permafrost soils as well as fire-flooding wells came later. The reason for the use in geothermal wells were severe problems with API Portland cements affected by hot, carbonic acid rich formation brines. With support from the companies Unocal and Halliburton, the Brookhaven National Laboratory (USA) developed a special cement based on 60 parts by weight of calcium aluminate cement and 40 parts ASTM class F fly ash. This binder is notably CO{sub 2} resistant when mixed with a 25 wt.% Na-polyphosphate solution. Laboratory tests and field applications conclude that this cement is resistant to CO{sub 2} corrosion at temperatures up to 300 C for over 20 years. In 1997, for the first time numerous geothermal wells have been cemented using this cement. They are intact to this day. When this cement hardens at room temperature, amorphous reaction products are formed and the reaction is incomplete. However, at higher temperatures hydroxyapatite, boehmite, Na-P-zeolite, analcime or katoite are formed as crystalline reaction products. The CO{sub 2} resistance of this cement is due to specific chemical reactions. In contact with hot alkaline carbonate solutions, analcime converts to cancrinite, and CO{sub 2} is incorporated into

  14. Rotary kiln incinerator engineering tests on simulated transuranic wastes from the Idaho National Engineering Laboratory. Final report

    Pattengill, M.G.; Brunner, F.A.; Fasso, J.L.; Mitchel, S.R.; Praskac, R.T.

    1982-09-01

    Nine rotary kiln incineration tests were performed at Colorado School of Mines Research Institute on simulated transuranic waste materials. The rotary kiln incinerator used as 3 ft ID and 30 ft long and was included in an incineration system that also included an afterburner and a baghouse. The purpose of the incineration test program was to determine the applicability and operating characteristics of the rotary kiln with relation to the complete incineration of the simulated waste materials. The results of the study showed that the rotary kiln did completely incinerate the waste materials. Off-gas determinations showed emission levels of SO 2 , NO/sub x/, H 2 SO 4 , HC1, particulate loading, and hydrocarbons, as well as exhaust gas volume, to be within reasonable controllable ranges in a production operation. Included in the report are the results of materials and energy balances, based upon data collected, and design recommendations based upon the data and upon observations during the incineration operation

  15. Compacting of fly dusts from cupola and electric arc furnace

    D. Baricová

    2012-01-01

    Full Text Available Recycling and utilization of dust waste is important not only from the point of view of its usage as an alternative source of raw materials, but regarding the environmental problems also. Dust emissions arise from thermal and chemical or physical processes and mechanical actions. Two kinds of fl y dusts from cupola furnaces (hot and cold blast cupola furnace and fl y dust from electric arc furnace were used by experiments. They were pelletized only with addition of water and briquetted with diff erent addition of water glass, bentonite and cement. Quality of briquettes was tested by compression – strength test and by break down test in green state, after drying and afterstoring (1 month.

  16. Basic investigation on promotion of joint implementation in fiscal 2000. Energy conservation and modernization plan for Chhatak Cement Co., Ltd.; 2000 nendo kyodo jisshi nado suishin kiso chosa hokokusho. Chhatak Cement sha shoene, kindaika keikaku

    NONE

    2001-03-01

    With an objective of saving energies and reducing greenhouse gas emission, discussions were given on a modernization plan for the Chhatak cement factory in The People's Republic of Bangladesh. The Chhatak cement factory having a nominal production capability of 267,000 tons a year uses mainly wet-type long kilns of old type, consuming a great amount of natural gas. The present plan has discussed adoption of the Japanese energy saving technologies. The technologies use a vertical roller mill for raw material pulverization, a suspension preheater and a short kiln for clinker sintering, a grate cooler for clinker cooling, and the pre-crushing system. The result of the discussions provided the prospects of reduction in the natural gas consumption at 50%, and reduction of electric power consumption at 16%. This will mean the annual reduction of about 22,000 tons as converted to crude oil. The CO2 reduction amount would reach 51,800 tons a year. The total investment amount would be US$37,327,000. The result of the financial analysis according to the case studies appears severe, wherein reduction of the various expenses is desired possibly by the finance from Japan with generous conditions.(NEDO)

  17. FY 2000 report on the basic survey to promote Joint Implementation, etc. Upgrading of energy utilization in the cement production process; 2000 nendo kyodo jisshi nado suishin kiso chosa hokokusho. Cement seizo kotei ni okeru energy kodoka

    NONE

    2001-03-01

    An investigational study was conducted of a project for energy conservation and greenhouse effect gas reduction by introducing the steam injection gas turbine generator to production facilities of the Siam Cement Industry Corporation (SCI) in Thailand. In the project, studies were made on the following: no purchases of electric power by introduction of the steam injection gas turbine generator; additional heating by gas turbine exhaust gas by introduction of the kiln combustion air heater; remodeling of the preheater of raw materials, and the partial calcination before kiln sintering by introduction of the calcination furnace. As a result of the study, the energy conservation amount was 1,200 toe/y, and the greenhouse effect gas reduction amount was approximately 8,000 t-CO2/y, which led to the reserve power for increased production of clinker by about 18%. The size of investment was 314.5 million Baht in total. As to the evaluation of economical efficiency of the investment, the actual period of ROI was a little less than 5 years, and the internal earning rate was 17.7%, which substantially met with SCI's standards for equipment investment. However, there are problems on the gas supply infrastructure, recovery of the white cement demand, etc. (NEDO)

  18. Energy Efficient Microwave Hybrid Processing of Lime for Cement, Steel, and Glass Industries

    Fall, Morgana L; Yakovlev, Vadim; Sahi, Catherine; Baranova, Inessa; Bowers, Johnney G; Esquenazi\t, Gibran L

    2012-02-10

    MAT in the US lime industry. This estimate showed that 7.3 TBTU/year could be saved, with reduction of 270 MMlbs of CO2 emissions, and $29 MM/year in economic savings. Taking into account estimates for MAT implementation in the US cement industry, an additional 39 TBTU/year, 3 Blbs of CO2 and $155 MM/year could be saved. One of the main remaining barriers to commercialization of MAT for the lime and cement industries is the sheer size of production. Through this project, it was realized that a production size MAT rotary calciner was not feasible, and a different approach was adapted. The concept of a microwave post heat section located in the upper portion of the cooler was devised and appears to be a more realistic approach for MAT implementation. Commercialization of this technology will require (1) continued pilot scale calcining demonstrations, (2) involvement of lime kiln companies, and (3) involvement of an industrial microwave equipment provider. An initial design concept for a MAT post-heat treatment section was conceived as a retrofit into the cooler sections of existing lime rotary calciners with a 1.4 year payback. Retrofitting will help spur implementation of this technology, as the capital investment will be minimal for enhancing the efficiency of current rotary lime kilns. Retrofits would likely be attractive to lime manufacturers, as the purchase of a new lime kiln is on the order of a $30 million dollar investment, where as a MAT retrofit is estimated on the order of $1 million. The path for commercialization lies in partnering with existing lime kiln companies, who will be able to implement the microwave post heat sections in existing and new build kilns. A microwave equipment provider has been identified, who would make up part of the continued development and commercialization team.

  19. Comparison of two kiln-drying schedules for turkish hazel ( Corylus colurna ) lumber of 5-cm thickness

    Korkut, Süleyman; As, Nusret; Büyüksari, Ümit

    2018-01-01

    Abstract: Turkish hazel (Corylus colurna) lumber with a nominal thickness of 5 cm from the Kastamonu region, Turkey, was dried through conventional kiln drying using two different programs, a non-protective drying schedule and a protective drying schedule. The goal of the study was to obtain a kiln schedule that would maintain wood quality and also save drying time until a final moisture content of 8 ± 2% was reached. The intensity of warping (twisting, bowing, cupping, crooking), superficial...

  20. [Silicosis and industrial bronchitis by exposure to silica powders and cement].

    Méndez-Vargas, María Martha; Báez-Revueltas, Fabiola Berenice; López-Rojas, Pablo; Tovalín-Ahumada, José Horacio; Zamudio-Lara, José Othón; Marín-Cotoñieto, Irma Araceli; Villeda, Francisco

    2013-01-01

    to identify the association between the exposure of workers to inorganic dust in a quarry and a cement factory and pulmonary diseases. a transverse study on data from 32 quarry workers (QWs) and 57 cement production line workers (CFWs) to inorganic-dust exposure was performed. Pulmonary function tests and chest X ray were done in both groups. there were differences between QWs and the CFWs; QWs were younger, shorter and thinner. The number of sick individuals might be considered significantly different, showing a smaller proportion on the cement production line. The quarry workers have been on the company for a shorter period of time and, in the end, they present more serious pulmonary problems with an average of 3 years working. the amount of free-silica that is managed on the quarry affects the workers in some way, even when literature states that the evolution of industrial bronchitis and silicosis have a period development of approximately 10 years.

  1. Determination of heavy metals in agricultural soil adjacent to functional brick kilns: a case study of rawalpindi

    Achakzai, K.; Khalid, S.; Bibi, A.

    2017-01-01

    Brick making is one of the growing industry of Pakistan which had great contribution in the development of country. In order to meet the demands of urbanization the industry's production rate is also increasing. This has lead to the combustion of enormous amount of coal and other materials thus deteriorating the quality of environment. Brick kilns in developing countries are considered as one of the important source of pollution. Heavy metals are one of the reported pollutants from brick kilns and are highly persistent, non-biodegradable in nature and are serious threat to the environment. The aim of the current study was to assess the level of heavy metals in the soil and vegetation around three selected brick kilns sites in Rawalpindi. The study was conducted from October 2013 to May 2014. The concentration of heavy metals in the soil and plants were determined with standard protocols. The investigated concentration of heavy metals in plants and soils were compared with the WHO standards. It was found that the concentrations of all studied metals were above the permissible limits especially at agriculture soil located adjacent to brick kilns. However, at few sites the concentrations were found below the permissible limits. The results of study showed that brick kilns have great potential of deteriorating the quality of environment so, it is recommended that the monitoring of soil and plants around brick kilns should be carried out on regular basis in order to develop control measures to prevent the impacts of heavy metals pollution. (author)

  2. A feasibility study to determine the functionality of a novel rocking kiln - fluidized bed reactor for the treatment of waste

    Mohamad Azman Che Mat Isa; Muhd Noor Muhd Yunus; Mohamad Puad Abu; Shahazrin Mohd Nasir; Mohd fairus Abdul Farid

    2004-01-01

    Rotary kiln has been widely used in incineration and studied by many researches. Solid wastes of various shapes, sizes and heat value can be fed into rotary kiln either in batches or continually. Waste combustion in rotary kiln involves rotation method and the residence time depends on the length and diameter of the rotary kiln and the total stoichiometric air given to the system. Rocking system is another technology used in incinerator. In the rocking system, internal elements in the combustion chamber move to transports and mix the burning waste so that all combustible material in the waste is fully burnt. Another technology in incinerator is the fluidized bed This method uses air to fluidized the sand thus enhancing the combustion process. The total air is controlled in order to obtain a suitable fluidized condition This preliminary study was conducted to study the feasibility of an incinerator system when three components viz. the rotary kiln, rocking system and fluidized bed are combined This research was also conducted to obtain preliminary data parameters of the three components such as the suitable temperature, the angle of the kiln, residence time, total air for fluidization, rocking speed and the devolatilization rate. The samples used in this research were the palm oil kernel shells. The results of the studies showed that the palm oil kernel shells combusted evenly using the new parameters. (Author)

  3. LADEE LUNAR DUST EXPERIMENT

    National Aeronautics and Space Administration — This archive bundle includes data taken by the Lunar Dust Experiment (LDEX) instrument aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft....

  4. Construction dust amelioration techniques.

    2012-04-01

    Dust produced on seasonal road construction sites in Alaska is both a traffic safety and environmental concern. Dust emanating from : unpaved road surfaces during construction severely reduces visibility and impacts stopping sight distance, and contr...

  5. On Dust Charging Equation

    Tsintsadze, Nodar L.; Tsintsadze, Levan N.

    2008-01-01

    A general derivation of the charging equation of a dust grain is presented, and indicated where and when it can be used. A problem of linear fluctuations of charges on the surface of the dust grain is discussed.

  6. Physics of interstellar dust

    Krugel, Endrik

    2002-01-01

    The dielectric permeability; How to evaluate grain cross sections; Very small and very big particles; Case studies of Mie calculus; Particle statistics; The radiative transition probability; Structure and composition of dust; Dust radiation; Dust and its environment; Polarization; Grain alignment; PAHs and spectral features of dust; Radiative transport; Diffuse matter in the Milky Way; Stars and their formation; Emission from young stars. Appendices Mathematical formulae; List of symbols.

  7. Dust as a surfactant

    Ignatov, A M; Schram, P P J M; Trigger, S A

    2003-01-01

    We argue that dust immersed in a plasma sheath acts as a surfactant. By considering the momentum balance in a plasma sheath, we evaluate the dependence of the plasma surface pressure on the dust density. It is shown that the dust may reduce the surface pressure, giving rise to a sufficiently strong tangential force. The latter is capable of confining the dust layer inside the sheath in the direction perpendicular to the ion flow

  8. Study on the pelletizing of sulfate residue with magnetite concentrate in grate-kiln system

    Shufeng Y.

    2010-01-01

    Full Text Available The experiment on the feasibility of pelletizing with magnetite concentrate and the wasted sulfate residue was carried out, to research the performance of pellet in grate-kiln system and simulate the grate-kiln pelletizing process in the micro-pellet roasting simulation system in laboratory, and the process experiments on preheating and roasting sections were conducted. The results show that in order to obtain pellet with good performance and the magnetite concentrate should be over 20 in mass percent, the suitable pelletizing time is about 10 min and moisture is around 12.5%. Also, according to the process parameters of drying and preheating sections obtained from experiment, it will be successful to use magnetite concentrate and the wasted sulfate residue for pelletizing, which exploits a new way for the use of sulfate residue.

  9. Emissions of air toxics from a simulated charcoal kiln. Final report, October 1997--September 1998

    Lemieux, P.M.

    1999-06-01

    The report gives results of experiments in a laboratory-scale charcoal kiln simulator to evaluate emissions of hazardous air pollutants from the production of charcoal in Missouri-type kilns. Fixed combustion gases were measured using continuous monitors. In addition, other pollutants, including methanol, volatile organic compounds, semivolatile organic compounds, and particle emission rates and size distributions were measured using various techniques. Emissions of all pollutants are reported in units of grams emitted per unit mass of initial wood converted to charcoal. Two burn conditions--slow and fast--were examined. High levels of methanol, benzene, and fine particulate were emitted in all tests. The estimated emissions from the fast burn conditions were significantly higher than those from the slow burn conditions

  10. Energy consumption analysis and simulation of waste heat recovery technology of ceramic rotary kiln

    Chen, Zhiguang; Zhou, Yu; Qin, Chaokui; Zhang, Xuemei

    2018-03-01

    Ceramsite is widely used in the construction industry, insulation works and oil industry in China, and the manufacture equipment is mainly industrial kiln. In this paper, energy consumption analysis had been carried out through experimental test of a Ceramsite kiln in Henan province. Results showed that the discharge temperature of Ceramsite was about 1393K, and the waste heat accounted for 22.1% of the total energy consumption. A structure of cyclone preheater which recovered waste heat of the high temperature Ceramsite by blast cooling was designed. Then, using Fluent software, performance of the unit was simulated. The minimum temperature that Ceramsite could reach, heat dissipating capacity of Ceramsite, temperature at air outlet, wall temperature of the unit and pressure loss were analyzed. Performance of the designed unit under different inlet velocity was analyzed as well.

  11. Mineral resource of the month: hydraulic cement

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  12. Cement-latex grouting mortar for cementing boreholes

    Kateev, I S; Golyshkina, L A; Gorbunova, I V; Kurochkin, B M; Vakula, Ya V

    1980-01-01

    The need for the development of cement-latex grouting mortar for the purpose of separating strata when reinforcing boreholes at deposits in the Tatar Associated SSR is evaluated. Results of studies of the physical and mechanical properties of cement-latex grouting mortar systems (mortar plus brick) are presented. Formulas for preparing cement-latex grouting mortor are evaluated and results of industrial tests of such mortars shown.

  13. US cement industry

    Nisbet, M.A.

    1997-12-31

    This paper describes the cement and concrete industry, and provides data on energy use and carbon dioxide emissions. The potential impact of an energy tax on the industry is briefly assessed. Opportunities identified for reducing carbon dioxide emissions include improved energy efficiency, alternative fuels, and alternative materials. The key factor in determining CO{sub 2} emissions is the level of domestic production. The projected improvement in energy efficiency and the relatively slow growth in domestic shipments indicate that CO{sub 2} emissions in 2000 should be about 5% above the 1990 target. However, due to the cyclical nature of cement demand, emissions will probably be above target levels during peak demand and below target levels during demand troughs. 7 figs., 2 tabs.

  14. Element Content of Surface and Underground Water Sources around a Cement Factory Site in Calabar, Nigeria

    Edmund Richard Egbe

    2017-01-01

    Full Text Available Background: Cement production is associated with heavy metal emissions and environmental pollution by cement dust. The degree of contamination of drinking water sources by major and trace elements present in cement dust generated by united cement factory (UNICEM is still uncertain. This study estimated the element content of ground and surface water samples (hand-dug wells, boreholes and streams around the factory site to determine the impact of cement dust exposure on the water levels of these elements. Methods: This study was conducted at UNICEM at Mfamosing, Akamkpa local government area, Cross River State, Nigeria. Drinking water samples (5 from each location were collected from the cement factory quarry site camp, 3 surrounding communities and Calabar metropolis (45 km away from factory serving as control. The lead (Pb, copper (Cu, manganes (Mn, iron (Fe, cadmium (Cd, selenium (Se, chromium (Cr, zinc (Zn and arsenic (As levels of samples were determined using Atomic Absorption Spectrometry (AAS. Data were analyzed using ANOVA and LSD post hoc at P = 0.05. Results: As and Pb content of samples from camp were above the WHO recommendations of 0.01mg/l and 0.01mg/l respectively. Chromium and cadmium content of all water samples were above and others below WHO recommendations. Water levels of Mn, Fe, Zn, As, Se, Cd, Ca and Si were significantly elevated (though below WHO recommendations in camp than other locations (P<0.05. Conclusion: Production of cement results in As, Pb, Cr and cd contamination of drinking water sources near the factory. Treatment of all drinking water sources is recommended before public use to avert deleterious health consequences.

  15. Parametrication of numerical simulation of drying process in atypicall condenzation lumber kiln

    Jiří Zejda

    2004-01-01

    Full Text Available This work deal with modelling of the process of drying, air flow, temperature and moisture distribution in a condensation lumber kiln. This model was made and solved in the computing system ANSYS with the use of the finite element method. There are comparationes of the 2D and 3D models, shape of wood stacks and variability of their parameters (height, width, length, cross section in the work. The flow velocity and orientation, pressure and temperature field were observed.

  16. Prediction of the granulometric and morphological evolution of a powder in a continuous conversion kiln

    Patisson, F.; Hebrard, S.; Ablitzer, D.; Ablitzer-Thouroude, C.; Hebrard, S.

    2006-01-01

    The UO 2 powder used for the preparation of nuclear fuel pellets is obtained in France by a dry way conversion of gaseous UF 6 . The process includes two steps: hydrolysis into UO 2 F 2 , then reducing pyro-hydrolysis into UO 2 in a continuous conversion kiln. The physical characteristics (morphology, grain size distribution) of the obtained UO 2 powder condition its use properties (sintering ability, casting ability and mechanical strength). A model describing the morphological evolution of the powder in the continuous conversion kiln has been developed in order to dispose of a prediction tool for the morphological characteristics of the UO 2 powder according to its formation conditions. The first part of this work has consisted to model the transport of the powder in the kiln, describing particularly the exchanges between the dense phase (powder bed) and the dispersed phase (rain of particles suspension). One of the originality of the developed model is the taking into account of the role of the raising devices for the calculus of the dynamical variables. The second part has consisted to identify, describe and couple to the preceding dynamical model the phenomena responsible of the morphological and granulometric evolution of the powder in the continuous conversion kiln. A population of fractal agglomerates is considered whose number and size evolve by brownian agglomeration, differential sedimentation agglomeration, pre sintering, fragmentation, and chemical transformations by ex-nucleation and growth. This model uses the formalism of the population balances and the grain size distribution is discretized into sections. The results of the dynamical and morphological calculations are compared to the available measurements. At last is analyzed the respective influence of the different morphological evolution mechanisms on the ended grain size distribution. (O.M.)

  17. Characteristics of Timbers Dried Using Kiln Drying and Radio Frequency-Vacuum Drying Systems

    Rabidin Zairul Amin; Seng Gan Kee; Wahab Mohd Jamil Abdul

    2017-01-01

    Heavy hardwoods are difficult-to-dry timbers as they are prone to checking and internal stresses when dried using a conventional kiln drying system. These timbers are usually dried naturally to reach 15% to 19% moisture content with an acceptable defects. Besides long drying time, timbers at these moisture contents are not suitable for indoor applications since they will further dry and causing, for example, jointing and lamination failures. Drying to a lower moisture content could only be ac...

  18. A Numerical Assessment of the Air Flow Behaviour in a Conventional Compact Dry Kiln

    Paulo Zdanski; Daniel Possamai; Miguel Vaz Jr.

    2015-01-01

    Convective drying is the most common drying strategy used in timber manufacturing industries in the developing world. In convective drying, the reduction rate of the moisture content is directly affected by the flow topology in the inlet and exit plenums and the air flow velocity in the channels formed by timber layers.Turbulence, boundary layer separation, vortex formation and recirculation regions are flow features that are intrinsically associated with the kiln geometry, which in turn dict...

  19. Continuous pyrolysis of biomass feedstocks in rotary kiln convertors. Final report

    Henry, Jr, H. H.; Kimzey, J. R.; Turpin, J. L.; MacCallum, R. N.

    1979-08-30

    The biomass research program at the University of Arkansas has developed three experimental projects or tasks for the attainment of its objectives. They are: (1) utilization of the existing full scale convertor for testing and data acquisition at Jonesboro, Arkansas; (2) development of a scale model rotary pyrolytic convertor (bench scale research kiln); and (3) development of analytical laboratory services for the analysis of feedstocks and products, and for basic pyrolytic process studies. The project at Jonesboro, Arkansas, which aimed at testing the Angelo convertor concept through heat and material balances over the available range of operations, could not completely achieve this objective because of the severe mechanical and structural deficiencies in the full scale convertor. A limited number of data have been taken in spite of the deficiencies of the machine. The scale model rotary kiln has been the most successful of the three projects. The kiln has been completed as planned and successfully operated with a number of feedstock materials. Good qualitative data have been obtained on conversion rate capacities, charcoal yields, and off gas combustion product temperatures. In all, about one hundred test runs were made in the scale model kiln. About 90% of the results expected were attained. The laboratory services project was designed to provide analytical testing for the other two projects and to do basic studies in biomass material conversion processes. The project delivered the testing services, but was severely restricted in the area of basic studies because of the failure of the main instrument, the gas chromatograph, to operate successfully. In all it is estimated that this project attained about 80% of its expected goals.

  20. Development of Hybrid Kiln Drying System with Radio Frequency Heating for the Sugi Heart Timber

    Piao, Jinji; Fujimoto, Noboru; Yamamoto, Yasushi; Nagata, Soji

    2007-01-01

    In this study, proper applied stage of the radio-frequency (RF) heating during kiln drying based on the quality concerning the surface checks of the boxed heart timbers was examined. At the stage of the RF heating the moisture contents decreased clearly at the internal parts of timbers. The surface stress of the sugi (Cryptomeria japonica D. Don) boxed heart timber changed into the compression stress by the RF heating in any drying stage. The surface checks increased according to the decrease...

  1. Comparison of physical and mechanical properties of river sand concrete with quarry dust concrete

    Opara, Hyginus E.; Eziefula, Uchechi G.; Eziefula, Bennett I.

    2018-03-01

    This study compared the physical and mechanical properties of river sand concrete with quarry dust concrete. The constituent materials were batched by weight. The water-cement ratio and mix ratio selected for the experimental investigation were 0.55 and 1:2:4, respectively. The specimens were cured for 7, 14, 21 and 28 days. Slump, density and compressive strength tests were carried out. The results showed that river sand concrete had greater density and compressive strength than quarry dust concrete for all curing ages. At 28 days of curing, river sand concrete exceeded the target compressive strength by 36%, whereas quarry dust concrete was less than the target compressive strength by 12%. Both river sand concrete and quarry dust concrete for the selected water/cement ratio and mix ratio are suitable for non-structural applications and lightly-loaded members where high strength is not a prerequisite.

  2. Chemical environment in cements

    Glasser, F.B.; Angus, M.J.; McCulloch, C.E.; Macphee, D.; Rahman, A.A.

    1984-01-01

    The alkalinity of Portland cements is responsible for precipitation and low solubility of many radwastes species. The sources of alkalinity are evaluated and two chemical models, based on experimental and theoretical data presented enabling the effect of blending agents (PFA, silica fume, etc.) to be evaluated and the alkalinity of the system at longer ages predicted. The data take the form of a solubility model which is applicable to non-heat generating wastes. 7 refs., 10 figs

  3. Production Of Bio fuel Starter From Biomass Waste Using Rocking Kiln Fluidized Bed System

    Mohamad Azman Che Mat Isa; Muhd Noor Muhd Yunus; Zulkafli Ghazali; Mohd Zaid Mohamed; Phongsakorn, P.T.; Mohamad Puad Abu

    2014-01-01

    The biggest biomass source in Malaysia comes from oil palm industry. According to the statistic in 2010, Malaysia produced 40 million tones per year of biomass of which 30 million tones of biomass originated from the oil palm industries. The biomass waste such as palm kernel shell can be used to produce activated carbon and bio fuel starter. A new type of rotary kiln, called Rocking Kiln Fluidized Bed (RKFB) was developed in Nuclear Malaysia to utilize the large amount of the biomass to produce high value added products. This system is capable to process biomass with complete combustion to produce bio fuel starter. With this system, the produced charcoal has calorific value, 33MJ/ kg that is better than bituminous coal with calorific value, 25-30 MJ/ kg. In this research, the charcoals produced were further used to produce the bio fuel starter. This paper will elaborate the experimental set-up of the Rocking Kiln Fluidized Bed (RKFB) for bio fuel starter production and the quality of the produced bio fuel starter. (author)

  4. Improvements in Pyrolysis of Wastes in an Externally Heated Rotary Kiln

    Suzuki, Tomoko; Okazaki, Teruyuki; Yamamoto, Kenji; Nakata, Hiroyuki; Fujita, Osamu

    The effects of rotating speed and internal structure on the performance of an externally heated rotary kiln for waste pyrolysis were investigated. A newly developed method was adopted to evaluate the overall heat transfer coefficient km-w from the inner wall to the wastes for this purpose. The experimental results revealed that km-w monotonically increased with the number of lifters and their height. When six lifters 200 mm in height were attached to the inner wall of the kiln, the mean value of km-w increased from 38.6 W/m2K to 45.3 W/m2K at 2.7 rpm. In addition, km-w increased to 50.1 W/m2K when the rotating speed was increased to 4.0 rpm. In the water vaporization phase during the course of the pyrolysis process, the height of the lifters had a significant influence on km-w. However, the number of lifters had a significant impact on km-w in the pyrolysis phase of the plastic-based wastes. According to measurements, a 10 % increase in km-w could be obtained when installing lifters to attain a ratio of lifter height Hl to the thickness of the waste layer Hw larger than 0.45 or when arc length between two lifters Ll to the arc length of the interface between the wastes and the kiln wall Lw was larger than 1.

  5. Releasability of asbestos fibers from weathered roof cement.

    Oberta, Andrew F; Poye, Lee; Compton, Steven P

    2018-03-26

    Chrysotile asbestos fibers were added to roofing products, including roof cement, for several decades. The fibers were described as "encapsulated" and therefore incapable of being released, an assertion that is disproved by the study reported herein. Three test panels of roof cement from the original container were exposed to ambient weathering in 2015 and 2016. Two panels were then sampled using the ASTM D5755 microvacuum method. Sampling revealed a light brown sub-layer under the dark brown surface layer, both of which crumbled and became friable during sampling. Analysis of the microvacuum samples with transmission electron microscopy showed that the material on the two panels contained 4,432,000 and 3,320,000 asbestos structures per cm² with nearly all of the structures consisting of fibers less than 5 µm long. Energy dispersive spectrometry determined that none of the fibers reported were coated with asphalt. The presence of free fibers were confirmed by direct examination of the surfaces of the panels and of dust released from handling the panels via scanning electron microscopy. This study confirmed the releasability of uncoated asbestos fibers from dried roof cement that was indicated in two previous studies published in 2007 and 2010. These results suggest that the finding of the 5th Circuit Court in 1997 that uncoated airborne asbestos fibers cannot be released from roof cement, and therefore do not present a potential exposure by inhalation, was erroneous in retrospect. Theexemption of roof cement from regulation under the Occupational Safety and Health Administration Construction Industry Standard for asbestos by the Court should not be relied on by employers of workers who remove weathered asbestos-containing roof cement, and precautions should be taken against exposure to airborne asbestos fibers during this work.

  6. FY 2000 report on the basic survey to promote Joint Implementation, etc. Energy conservation by modernization of a cement plant (Double Horse Cement Co.) in China; 2000 nendo kyodo jisshi nado suishin kiso chosa hokokusho. Chugoku cement kojo (Double Horse Cement) kindaika ni yoru sho energy

    NONE

    2001-03-01

    An investigational study was conducted of possibilities of energy conservation and greenhouse effect gas emission reduction in the cement production process of Double Horse Cement Co., Mianyang City, Sichuan Province, China. Double Horse Cement adopts the wet type long kiln production system and has a production ability of approximately 1.5 million t/y. In the project, as to three production lines out of the six production lines, improvement was planned to be made of the technologies on the following: mixing of raw materials, grinding of raw materials, NSP, clinker cooler, clinker pre-grinder, high-efficiency separator, waste heat use power generation, etc. As a result of the study, it was found that the energy conservation amount obtained was 54,646 toe/y. And, the amount of greenhouse effect gas reduction was 169,086 t-CO2/y. The total fund required for this project was approximately 5.553 billion yen and the internal earning rate was 7.36% after tax. When the project is carried out, expenses vs. effects are 9.8 toe/million yen in energy conservation amount and 30.4 t-CO2/million yen in greenhouse effect gas reduction. (NEDO)

  7. Eco-efficiency of the world cement industry: A data envelopment analysis

    Oggioni, G., E-mail: oggioni@eco.unibs.i [University of Brescia, Faculty of Economics, Department of Quantitative Methods, IT-25122 Brescia (Italy); Riccardi, R., E-mail: riccardi@ec.unipi.i [University of Brescia, Faculty of Economics, Department of Quantitative Methods, IT-25122 Brescia (Italy); Toninelli, R., E-mail: roberta.toninelli@unifi.i [University of Pisa, Faculty of Economics, Department of Statistics and Applied Mathematics, IT-56124 Pisa (Italy)

    2011-05-15

    Chemical reactions and the combustion of dirty fuels, such as coal and petroleum coke (petcoke), that are used in cement production processes generate a significant amount of CO{sub 2} emissions. In this paper, we provide an eco-efficiency measure for 21 prototypes of cement industries operating in many countries by applying both a data envelopment analysis (DEA) and a directional distance function approach, which are particularly suitable for models where several production inputs and desirable and undesirable outputs are taken into account. To understand whether this eco-efficiency is due to a rational utilization of inputs or to a real carbon dioxide reduction as a consequence of environmental regulation, we analyze the cases where CO{sub 2} emissions can either be considered as an input or as an undesirable output. Empirical results show that countries where cement industries invest in technologically advanced kilns and adopt alternative fuels and raw materials in their production processes are eco-efficient. This gives a comparative advantage to emerging countries, such as India and China, which are incentivized to modernize their production processes.

  8. Influence of packing and dispersion of particles on the cement content of concretes

    B. L. DAMINELI

    Full Text Available Abstract Due to environmental issues, the concrete chain seeks to reduce CO2 emissions. However, growing demand from developing countries causes the increase of CO2 emissions in production to exceed decreases generated by industrial actions, such as improving kilns and clinker replacement. New strategies are important. Changes in the concrete formulation, making it more efficient, can help if these changes produce concrete with the same performance and lower cement consumption. In this regard, the improvement of packing and dispersion of particles increases this efficiency. The better the packing, the lower the volume of voids between particles, thereby requiring lower fluid content (water to permit flow. The dispersion of the particles also decreases the water content for the same fluidity. The less the water content, the smaller the water/cement (w/c ratio, and the greater the resistance. Thus, both strategies increase the efficiency by uncoupling obtaining fluidity from the water content. This study investigated the influence of packing and dispersion on the efficiency of cement use in concrete. The increase of packing and the complete dispersion of fine particles has been shown to improve efficiency, as measured by the ratio between binder consumption and compressive strength (the performance parameter used in most practical applications.

  9. Eco-efficiency of the world cement industry: A data envelopment analysis

    Oggioni, G.; Riccardi, R.; Toninelli, R.

    2011-01-01

    Chemical reactions and the combustion of dirty fuels, such as coal and petroleum coke (petcoke), that are used in cement production processes generate a significant amount of CO 2 emissions. In this paper, we provide an eco-efficiency measure for 21 prototypes of cement industries operating in many countries by applying both a data envelopment analysis (DEA) and a directional distance function approach, which are particularly suitable for models where several production inputs and desirable and undesirable outputs are taken into account. To understand whether this eco-efficiency is due to a rational utilization of inputs or to a real carbon dioxide reduction as a consequence of environmental regulation, we analyze the cases where CO 2 emissions can either be considered as an input or as an undesirable output. Empirical results show that countries where cement industries invest in technologically advanced kilns and adopt alternative fuels and raw materials in their production processes are eco-efficient. This gives a comparative advantage to emerging countries, such as India and China, which are incentivized to modernize their production processes.

  10. Stability of reinforced cemented backfills

    Mitchell, R.J.; Stone, D.M.

    1987-01-01

    Mining with backfill has been the subject of several international meetings in recent years and a considerable research effort is being applied to improve both mining economics and ore recovery by using backfill for ground support. Classified mill tailings sands are the most commonly used backfill material but these fine sands must be stabilized before full ore pillar recovery can be achieved. Normal portland cement is generally used for stabilization but the high cost of cement prohibits high cement usage. This paper considers the use of reinforcements in cemented fill to reduce the cement usage. It is concluded that strong cemented layers at typical spacings of about 3 meters in a low cement content bulk fill can reinforce the fill and reduce the overall cement usage. Fibre reinforcements introduced into strong layers or into bulk fills are also known to be effective in reducing cement usage. Some development work is needed to produce the ideal type of anchored fibre in order to realize economic gains from fibre-reinforced fills

  11. Thermal co-treatment of combustible hazardous waste and waste incineration fly ash in a rotary kiln.

    Huber, Florian; Blasenbauer, Dominik; Mallow, Ole; Lederer, Jakob; Winter, Franz; Fellner, Johann

    2016-12-01

    As current disposal practices for municipal solid waste incineration (MSWI) fly ash are either associated with significant costs or negative environmental impacts, an alternative treatment was investigated in a field scale experiment. Thereto, two rotary kilns were fed with hazardous waste, and moistened MSWI fly ash (water content of 23%) was added to the fuel of one kiln with a ratio of 169kg/Mg hazardous waste for 54h and 300kg/Mg hazardous waste for 48h while the other kiln was used as a reference. It was shown that the vast majority (>90%) of the inserted MSWI fly ash was transferred to the bottom ash of the rotary kiln. This bottom ash complied with the legal limits for non-hazardous waste landfills, thereby demonstrating the potential of the investigated method to transfer hazardous waste (MSWI fly ash) into non-hazardous waste (bottom ash). The results of a simple mixing test (MSWI fly ash and rotary kiln bottom ash have been mixed accordingly without thermal treatment) revealed that the observed transformation of hazardous MSWI fly ash into non-hazardous bottom ash during thermal co-treatment cannot be referred to dilution, as the mixture did not comply with legal limits for non-hazardous waste landfills. For the newly generated fly ash of the kiln, an increase in the concentration of Cd, K and Pb by 54%, 57% and 22%, respectively, was observed. In general, the operation of the rotary kiln was not impaired by the MSWI fly ash addition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Using dehydrated cement paste as new type of cement additive

    Yu, R.; Shui, Z.H.; Dong, J

    2013-01-01

    This paper presents an experimental study, including evaluation and modification, on using dehydrated cement paste (DCP) as a new type of cement additive. After a series of processes, normal DCP (N-DCP) was produced as before and a modified form of DCP (M-DCP) was produced as well. The cementitious

  13. Oxalate Acid-Base Cements as a Means of Carbon Storage

    Erdogan, S. T.

    2017-12-01

    Emission of CO2 from industrial processes poses a myriad of environmental problems. One such polluter is the portland cement (PC) industry. PC is the main ingredient in concrete which is the ubiquitous binding material for construction works. Its production is responsible for 5-10 % of all anthropogenic CO2 emissions. Half of this emission arises from the calcination of calcareous raw materials and half from kiln fuel burning and cement clinker grinding. There have long been efforts to reduce the carbon footprint of concrete. Among the many ways, one is to bind CO2 to the phases in the cement-water paste, oxides, hydroxides, and silicates of calcium, during early hydration or while in service. The problem is that obtaining calcium oxide cheaply requires the decarbonation of limestone and the uptake of CO2 is slow and limited mainly to the surface of the concrete due to its low gas permeability. Hence, a faster method to bind more CO2 is needed. Acid-base (AB) cements are fast-setting, high-strength systems that have high durability in many environments in which PC concrete is vulnerable. They are made with a powder base such as MgO and an acid or acid salt, like phosphates. Despite certain advantages over PC cement systems, AB cements are not feasible, due to their high acid content. Also, the phosphoric acid used comes from non-renewable sources of phosphate. A potential way to reduce the drawbacks of using phosphates could be to use organic acids. Oxalic acid or its salts could react with the proper powder base to give concrete that could be used for infrastructure hence that would have very high demand. In addition, methods to produce oxalates from CO2, even atmospheric, are becoming widespread and more economical. The base can also be an industrial byproduct to further lower the environmental impact. This study describes the use of oxalic acid and industrial byproducts to obtain mortars with mechanical properties comparable to those of PC mortars. It is

  14. The Lunar Dust Environment

    Szalay, Jamey Robert

    Planetary bodies throughout the solar system are continually bombarded by dust particles, largely originating from cometary activities and asteroidal collisions. Surfaces of bodies with thick atmospheres, such as Venus, Earth, Mars and Titan are mostly protected from incoming dust impacts as these particles ablate in their atmospheres as 'shooting stars'. However, the majority of bodies in the solar system have no appreciable atmosphere and their surfaces are directly exposed to the flux of high speed dust grains. Impacts onto solid surfaces in space generate charged and neutral gas clouds, as well as solid secondary ejecta dust particles. Gravitationally bound ejecta clouds forming dust exospheres were recognized by in situ dust instruments around the icy moons of Jupiter and Saturn, and had not yet been observed near bodies with refractory regolith surfaces before NASA's Lunar Dust and Environment Explorer (LADEE) mission. In this thesis, we first present the measurements taken by the Lunar Dust Explorer (LDEX), aboard LADEE, which discovered a permanently present, asymmetric dust cloud surrounding the Moon. The global characteristics of the lunar dust cloud are discussed as a function of a variety of variables such as altitude, solar longitude, local time, and lunar phase. These results are compared with models for lunar dust cloud generation. Second, we present an analysis of the groupings of impacts measured by LDEX, which represent detections of dense ejecta plumes above the lunar surface. These measurements are put in the context of understanding the response of the lunar surface to meteoroid bombardment and how to use other airless bodies in the solar system as detectors for their local meteoroid environment. Third, we present the first in-situ dust measurements taken over the lunar sunrise terminator. Having found no excess of small grains in this region, we discuss its implications for the putative population of electrostatically lofted dust.

  15. Process of preparing hydraulic cement

    1919-12-11

    A process of preparing hydraulic cement from oil shale or shale coke is characterized in that the oil shale or shale coke after the distillation is burned long and hot to liberate the usual amount of carbonic acid and then is fine ground to obtain a slow hardening hydraulic cement.

  16. Ceramic microspheres for cementing applications

    2011-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  17. Ceramic microspheres for cementing applications

    2010-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  18. Ceramic microspheres for cementing applications

    2012-01-01

    A method and apparatus for manufacturing ceramic microspheres from industrial slag. The microspheres have a particle size of about 38 microns to about 150 microns. The microspheres are used to create a cement slurry having a density of at least about 11 lbs/g. The resultant cement slurry may then be

  19. Modeling the Mixing of Components in a Rotary Kiln While Burning Municipal Waste to Ensure Rational Use of Energy

    Krot O.P.

    2017-08-01

    Full Text Available In Ukraine municipal waste is collected and delivered to a landfill. Municipal waste can be used as fuel to generate additional heat and electricity. The primary advantages of incineration are that waste volumes are reduced by an estimated, and the need for land and landfill space is greatly reduced. The plant has been designed by North–East Scientific Center using a thermocatalytic waste gas purification system with highly efficient dioxins reduction and heat energy recovery system. The technology of waste neutralization includes: a rotary kiln, an afterburner chamber, a new catalytic technologies for the treatment, a heat exchanger for heating combustion air, supply of alkali solution into the gas-escape channel, a carbon fiber adsorption filter. The organization of the right process of waste mixing in the rotary kiln allows increasing the efficiency of combustion, to equalize the combustion temperatures of the components of the waste and the completeness of the burning out of hazardous substances, which reduces the risk of their getting into the ash. The goal of the research is to build an analytical mathematical model of mixing of components in a rotary kiln. The model is based on the mathematical apparatus of Markov chains. The model allows to determine the concentration of the key component in any elementary volume of material circulating in the rotary kiln at any time and to calculate the statistical characteristics of the homogeneity of the mixture. The model will be used to research new designs of the equipment with rotary kilns.

  20. Investigating the Influence of Waste Basalt Powder on Selected Properties of Cement Paste and Mortar

    Dobiszewska, Magdalena; Beycioğlu, Ahmet

    2017-10-01

    Concrete is the most widely used man-made construction material in civil engineering applications. The consumption of cement and thus concrete, increases day by day along with the growth of urbanization and industrialization and due to new developments in construction technologies, population growing, increasing of living standard. Concrete production consumes much energy and large amounts of natural resources. It causes environmental, energy and economic losses. The most important material in concrete production is cement. Cement industry contributes to production of about 7% of all CO2 generated in the world. Every ton of cement production releases nearly one ton of CO2 to atmosphere. Thus the concrete and cement industry changes the environment appearance and influences it very much. Therefore, it has become very important for construction industry to focus on minimizing the environmental impact, reducing energy consumption and limiting CO2 emission. The need to meet these challenges has spurred an interest in the development of a blended Portland cement in which the amount of clinker is reduced and partially replaced with mineral additives - supplementary cementitious materials (SCMs). Many researchers have studied the possibility of using another mineral powder in mortar and concrete production. The addition of marble dust, basalt powder, granite or limestone powder positively affects some properties of cement mortar and concrete. This paper presents an experimental study on the properties of cement paste and mortar containing basalt powder. The basalt powder is a waste emerged from the preparation of aggregate used in asphalt mixture production. Previous studies have shown that analysed waste used as a fine aggregate replacement, has a beneficial effect on some properties of mortar and concrete, i.e. compressive strength, flexural strength and freeze resistance also. The present study shows the results of the research concerning the modification of cement

  1. Removal of cobalt and nickel from zinc sulphate solutions using activated cementation

    Boyanov B.

    2004-01-01

    Full Text Available The influence of different parameters (duration, temperature, zinc dust quantity, concentration of activators - copper and antimony on the process of activated cementation of Co and Ni has been studied. We have worked with industrial zinc sulphate solutions. During the process of activated cementation of Co and Ni, copper (involved as CuSO4.5H2O and antimony (involved as Sb2O3 were used as activators. The lowest values of Co content have been obtained at a temperature of 80-85 oC, CCu = 200-300 mg/dm3 and 18 multiple surplus of zinc dust. After adding Cu to the solution, mainly the cementation of Ni is activated, and that of Co is activated to a lower degree. It was found that when GSb : GCo ratio is between 0.5 : 1 and 2 : 1, the solution is purified from Co and Ni to a great degree. After intensive stirring and increasing the duration of the process the cement sediments dissolve reversely. This holds true of Co to a greater extent, as compared to Ni. The results obtained will be used to establish optimal conditions for the carrying out of activated cementation in Zinc Production Plant in KCM SA, Plovdiv.

  2. Corrosion resistant cemented carbide

    Hong, J.

    1990-01-01

    This paper describes a corrosion resistant cemented carbide composite. It comprises: a granular tungsten carbide phase, a semi-continuous solid solution carbide phase extending closely adjacent at least a portion of the grains of tungsten carbide for enhancing corrosion resistance, and a substantially continuous metal binder phase. The cemented carbide composite consisting essentially of an effective amount of an anti-corrosion additive, from about 4 to about 16 percent by weight metal binder phase, and with the remaining portion being from about 84 to about 96 percent by weight metal carbide wherein the metal carbide consists essentially of from about 4 to about 30 percent by weight of a transition metal carbide or mixtures thereof selected from Group IVB and of the Periodic Table of Elements and from about 70 to about 96 percent tungsten carbide. The metal binder phase consists essentially of nickel and from about 10 to about 25 percent by weight chromium, the effective amount of an anti-corrosion additive being selected from the group consisting essentially of copper, silver, tine and combinations thereof

  3. Dust Devil Tracks

    2002-01-01

    (Released 8 May 2002) The Science This image, centered near 50.0 S and 17.7 W displays dust devil tracks on the surface. Most of the lighter portions of the image likely have a thin veneer of dust settled on the surface. As a dust devil passes over the surface, it acts as a vacuum and picks up the dust, leaving the darker substrate exposed. In this image there is a general trend of many of the tracks running from east to west or west to east, indicating the general wind direction. There is often no general trend present in dust devil tracks seen in other images. The track patterns are quite ephemeral and can completely change or even disappear over the course of a few months. Dust devils are one of the mechanisms that Mars uses to constantly pump dust into the ubiquitously dusty atmosphere. This atmospheric dust is one of the main driving forces of the present Martian climate. The Story Vrrrrooooooooom. Think of a tornado, the cartoon Tasmanian devil, or any number of vacuum commercials that powerfully suck up swirls of dust and dirt. That's pretty much what it's like on the surface of Mars a lot of the time. Whirlpools of wind called

  4. Risk Assessment to Dust Exposure in Room Maintenance

    Saiku Rokhim

    2017-04-01

    Full Text Available As one of the particulate chemicals, dust could occur in most of the production process and can create interference for workers health and safety. As one of the air pollution sources, dust could became a potential hazard which exist in room maintenances. Protection to workers is a must in order to reduce the risk of respiratory tract syndrome that often could be found in this cases. The aim of this study is to conduct a risk assessment to dust exposure in room maintenance, which held by contractors in PT. X (Persero building in Surabaya. This is an cross sectional study with obsevation approach. The object of this research is the repairing  works. The results indicate that the activities which could produce dust, such as: walls sanding using sandpaper, the tiles dismantle, sawmilling, the wood fiber refining, grinding, mixing and stirring cast  materials, and room cleaning. Dust produced from a variety of works including sanddust, cement, lime, wood and dust mixed with paint. The results show that three types of works considere as high-risk activity (value > 12-25, 3 types of work consider as midle risk activities (value > 5-12, and one activity considered as a low-risk work (grades 1-5. The dusk factors controlling should be held regularly, in order to minimize the risk leveln againts the workers.

  5. New archaeomagnetic data from three roman kilns in northeast Spain: a contribution to the Iberian palaeosecular variation curve

    Beamud, E.; Gómez-Paccard, M.; McIntosh, G.; Larrasoaña, J. C.

    2012-04-01

    New archaeomagnetic results from three kilns recovered from a roman age archaeological site in Badalona (northeast Spain) are reported. Archaeological evidences constrain the abandonment of kilns BC1 and BC2 between 0 and 50 yrs AD, whereas the abandonment of kiln BC3 is established between 50 and 150 yrs AD. In order to perform the archaeomagnetic study 12 to 14 samples per kiln were collected using a portable electrical drill with a water-cooled diamond bit, following standard palaeomagnetic sampling methods. Samples were distributed all around the combustion chambers, being obtained in different orientations from the burnt walls and central pillars. Rock magnetic measurements revealed a dominance of low titanium titanomagnetite or substituted magnetite as the main carrier of the magnetic signal and a minor contribution of maghemite. The presence of single domain material, along with the thermal stability of the samples, means that they are suitable candidates for archaeomagnetic studies, and in particular intensity determinations. Archaeomagnetic experiments were attempted on 32 specimens characterised by NRM intensities between 0.5 and 8.3 A/m. Mean archaeomagnetic directions and archaeointensities have been obtained from the original Thellier method with regular partial thermoremanent magnetisation (pTRM) checks being used to estimate archaeointensities. Mean intensities of 68.3 ± 4.2 µT, 72.4 ± 5.0 µT and 72.9 ± 3.7 µT were obtained for kilns BC1, BC2 and BC3, respectively. A cooling rate correction factor of 5% has been applied to mean intensities and the values obtained have been relocated to Paris and Madrid through the virtual dipole moment VDM. The mean directions of the characteristic magnetization of each kiln and their associated statistical parameters were derived from principal component analysis and Fisher statistics. Very similar directions were obtained for BC1 and BC2 with the circle of confidence (α95) of the BC2 direction falling within

  6. Evaluation of the release of dioxins and PCBs during kiln-firing of ball clay.

    Broadwater, Kendra; Meeker, John D; Luksemburg, William; Maier, Martha; Garabrant, David; Demond, Avery; Franzblau, Alfred

    2014-01-01

    Ball clay is known to be naturally contaminated with high levels of polychlorinated di-benzo-p-dioxins (PCDDs). This study evaluated the potential for PCDD, polychlorinated dibenzofuran (PCDF) and polychlorinated biphenyl (PCB) release during the kiln firing of ball clay in an art studio. Toxic equivalence (TEQ) were calculated using World Health Organization (WHO) 2005 toxic equivalence factors (TEF) and congener concentrations. Ten bags of commercial ball clay were found to have an average TEQ of 1,370 nanograms/kilogram (ng kg(-1)) dry weight (dw), almost exclusively due to PCDDs (99.98% of TEQ). After firing, none of the 29 dioxin-like analytes was measured above the limits of detection (LOD) in the clay samples. Air samples were taken during firings using both low-flow and high-flow air samplers. Few low-flow air samples contained measurable levels of dioxin congeners above the LOD. The mean TEQ in the high volume air samples ranged from 0.07 pg m(-3) to 0.21 pg m(-3) when firing ball clay, and was 0.11 pg m(-3) when no clay was fired. These concentrations are within the range measured in typical residences and well-controlled industrial settings. The congener profiles in the high-flow air samples differed from the unfired clay; the air samples had a considerable contribution to the TEQ from PCDFs and PCBs. Given that the TEQs of all air samples were very low and the profiles differed from the unfired clay, it is likely that the PCDDs in dry ball clay were destroyed during kiln firing. These results suggest that inhalation of volatilized dioxins during kiln firing of dry ball clay is an unlikely source of exposure for vocational and art ceramicists. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Thermal energy analysis of a lime production process: Rotary kiln, preheater and cooler

    Shahin, Hamed; Hassanpour, Saeid; Saboonchi, Ahmad

    2016-01-01

    Highlights: • The integrated model for lime production unit which includes cooler, preheater and rotary kiln is developed. • The effect of residence time in each section on efficiency is investigated. • Influence of material feed rate and excess air on specific fuel consumption is analyzed. • The significant effect of particle size on efficiency and specific fuel consumption is shown. - Abstract: In this paper, thermal energy analysis of three zones of a lime production process, which are preheater, rotary kiln and cooler, is performed. In order to perform a proper quantitative estimation, the system was modeled using energy balance equations including coupled heat transfer and chemical reaction mechanisms. A mathematical model was developed, and consequently, the thermal and chemical behavior of limestone was investigated. The model was verified using empirical data. After model confirmation, the variation of Specific Fuel Consumption (SFC) versus production rate was predicted and the optimum condition was determined. Subsequently, fuel consumption was calculated regarding to altered residence time inside each zone of lime production process, for a constant output. Results indicate that increasing the residence time inside each zone of lime production process, will enhance thermal efficiency and saves fuel consumption. Relative enhancement will be the same for different sizes of limestone. It was found that a 10-min increase in material residence time inside the preheater or rotary kiln can reduce fuel consumption by around two percent. Whereas, a 5-min increase in material residence time inside the cooler would be enough to obtain a similar result. Finally, the ratio of air-to-fuel and production rate are changed in such a way that the same product is achieved. The model predicts that lowering excess air from 15% to 10% leads to a 2.5% reduction of Specific Fuel Consumption (SFC).

  8. Parameters of Concrete Modified with Glass Meal and Chalcedonite Dust

    Kotwa, Anna

    2017-10-01

    Additives used for production of concrete mixtures affect the rheological properties and parameters of hardened concrete, including compressive strength, water resistance, durability and shrinkage of hardened concrete. By their application, the use of cement and production costs may be reduced. The scheduled program of laboratory tests included preparation of six batches of concrete mixtures with addition of glass meal and / or chalcedonite dust. Mineral dust is a waste product obtained from crushed aggregate mining, with grain size below 0,063μm. The main ingredient of chalcedonite dust is silica. Glass meal used in the study is a material with very fine grain size, less than 65μm. This particle size is present in 60% - 90% of the sample. Additives were used to replace cement in concrete mixes in an amount of 15% and 25%. The amount of aggregate was left unchanged. The study used Portland cement CEM I 42.5R. Concrete mixes were prepared with a constant rate w / s = 0.4. The aim of the study was to identify the effect of the addition of chalcedonite dust and / or glass meal on the parameters of hardened concrete, i.e. compressive strength, water absorption and capillarity. Additives used in the laboratory tests significantly affect the compressive strength. The largest decrease in compressive strength of concrete samples was recorded for samples with 50% substitutes of cement additives. This decrease is 34.35%. The smallest decrease in compressive strength was noted in concrete with the addition of 15% of chalcedonite dust or 15% glass meal, it amounts to an average of 15%. The study of absorption shows that all concrete with the addition of chalcedonite dust and glass meal gained a percentage weight increase between 2.7 ÷ 3.1% for the test batches. This is a very good result, which is probably due to grout sealing. In capillary action for the test batches, the percentage weight gains of samples ranges from 4.6% to 5.1%. However, the reference concrete obtained

  9. Whither Cometary Dust?

    Lisse, Carey M.

    2010-10-01

    In this paper I will discuss recent findings that have important implications for our understanding of the formation and evolution of primitive solar system dust, including: - Nesvorny et al. (2010), following up on their dynamical analyses of the zodiacal dust bands as sourced by the breakup of the Karin (5Mya) and Veritas (8Mya) asteroid families, argue that over 90% of the interplanetary dust cloud at 1 AU comes from JFC comets with near-circularized, low inclination orbits. This implies that the noted IPD collections of anhydrous and hydrous dust particles are likely to be from Oort cloud and JFC comets, respectively, not from asteroids and comets as thought in the past. Hydrous dust particles from comets like 85P/Wild2 and 9P/Tempel 1 would be consistent with results from the STARDUST and Deep Impact experiments. - Estimates of the dust particle size distributions (PSDs) in the comae of 85P/Wild2 (Green et al. 2004, 2007) and 73P/SW-3 (Sitko et al. 2010, Vaubaillon & Reach 2010) and in the trails of comets (Reach et al. 2007) have broken power law structure, with a plateau enhancement of particles of 1 mm - 1 cm in size. This size is also the size of most chondritic inclusions, and the predicted size range of the "aggregational barrier", where collisions between dust particles become destructive. - Studies of the albedo and polarization properties of cometary dust (Kolokolova et al. 2007) suggest there are 2 major groupings, one with low scattering capability and one with high. While these families could possibly have been explained by systematics in the PSDs of the emitted dust, independent work by Lisse et al. (2008) on the mineralogy of a number of highly dusty comets has shown evidence for one family of comets with highly crystalline dust and another with highly amorphous dust.

  10. White-and-blud porcelain of Hutian kiln in Ming dynasty studied by PIXE

    Cheng Lin; Feng Songlin; Sha Yin; Cheng Huansheng

    2004-01-01

    The study of provenance, ages and distinguishing precious ancient porcelain from a fake of Chinese ancient porcelain by modern technologies arose greatly interesting in the circles of archaeologists and scientists in China. Concentration of major and trace elements of white-and-blue porcelain of Hutian kiln in Ming Dynasty were analyzed by PIXE, and elemental distributions of porcelain were analyzed by SPM. The results indicate the elemental distributions in the white glaze, blue glaze and body are homogeneous, respectively. It is a layer nearly 5-10 μm between the body and blue glaze. Probably, cobalt blue pigment used in the blue glaze comes from Jiangxi, Fujian province etc. (authors)

  11. New archeointensity results from the reconstructed ancient kiln by the Tsunakawa-Shaw method

    Yamamoto, Y.; Hatakeyama, T.; Kitahara, Y.; Saito, T.

    2017-12-01

    Yamamoto et al. (2015) reported that baked clay samples from the floor of a reconstructed ancient kiln provided a reliable Tsunakawa-Shaw (LTD-DHT Shaw) archeointensity (AI) estimate of 47.3 +/- 2.2 microT which is fairly consistent with the in situ geomagnetic field of 46.4 microT at the time of the reconstruction. The reconstruction was conducted to reproduce an excavated kiln of the seventh century in Japan and Sue-type potteries of contemporary style were also fired (Nakajima et al., 1974). Two of the potteries with reddish color were recently subjected to the Tsunakawa-Shaw archeointensity determinations, resulting in reliable AI estimates of 45.4 +/- 2.3 (N=6) and 48.2 +/- 2.7 microT (N=15) when specimens were heated in air in laboratory (Yamamoto et al., 2017 JpGU-AGU Joint Meeting). We have had another opportunity to take samples from a new reconstructed ancient kiln in Japan which was fired in autumn 2016. The samples were two Sue-type potteries with grayish color (bowl-type and plate-type) and some blocks collected from inner wall of the kiln body. They were cut into mini specimens and then subjected to the Tsunakawa-Shaw experiment. Heating in laboratory was done either in air or vacuum.For the bowl-type pottery, AIs of 46.9 +/- 2.8 (N=6, air) and 45.3 +/- 2.3 microT (N=6, vacuum) are obtained. They are indistinguishable each other and consistent with the IGRF field of 47.4 microT at the reconstructed location in 2016. For the plate-type pottery, AIs result in 41.8 +/- 1.3 (N=4, air) and 43.9 +/- 3.9 microT (N=4, vacuum). They are also indistinguishable each other but the former AI is slightly lower than the IGRF field.For the inner wall, AIs of 45.0 (N=1, air) and 46.8 microT (N=1, vacuum) are obtained from a right-side wall, and those of 45.5 +/- 2.5 (N=2, air) and 47.7 +/- 3.0 microT (N=2, vacuum) are observed from a left-side wall. They are all indistinguishable and consistent with the IGRF field.

  12. Validity of archaeomagnetic field recording: an experimental pottery kiln at Coppengrave, Germany

    Schnepp, Elisabeth; Leonhardt, Roman; Korte, Monika; Klett-Drechsel, Johannes

    2016-04-01

    Palaeomagnetic data obtained from archaeological materials are used for reconstructions of the Earth's magnetic field of the past millennia. While many studies tested the reliability of this recorder for palaeointensity only a few studies did this for direction. The study presents an archaeomagnetic and rock magnetic investigation applied to an experimental pottery kiln, which was operated in 2003 to produce stone ware. This kind of high-quality pottery needs a temperature of at least 1160 °C. Shortly before heating of the kiln direct absolute measurements of the absolute geomagnetic field vector have been carried out close to it. After cooling of the kiln 24 oriented palaeomagnetic samples have been taken. Although Curie temperatures are about 580 °C, that is the typical temperature for magnetite, thermal as well as alternating field demagnetisations reveal also a considerable amount of hematite as magnetic carrier. This mixture of magnetite and hematite is dominated by pseudo-single domain grains. Demagnetisation removed in some cases weak secondary components, but in most cases the specimens carried a single component thermoremanent magnetisation. The mean characteristic remanent magnetisation direction agrees on 95 per cent confidence level with the directly measured field direction. Archaeointensity was obtained from five specimens with the Thellier-Coe method and with the multiple-specimen palaeointensity domain-state corrected method. Six of these specimens also provided a result of the Dekkers-Böhnel method, which overestimated the archaeointensity by about 9 per cent compared to the direct value, while after correction for fraction the value agrees very well. For the multiple-specimen palaeointensity domain-state corrected method only fractions between 25 and 75 per cent have been used and specimens showing alteration have been excluded. Above 450 °C many specimens showed alteration of the magnetic grains. Because median destructive temperatures were

  13. A methodological proposal for ancient kiln simulation analyzed by Moessbauer spectroscopy

    Flores, E.; Fernandes, B.; Flores, E.; Fernandez, B.

    1988-01-01

    In previous papers scientistis from different countries have reported simulating incomplete methodologies for ancient kiln firing conditions. Results from clays fired in a first working hypothesis are presented to end as a methodological proposal for simulation. This study was done through Moessbauer spectroscopy. The fired clay used presented a Fe 2+ and Fe 3+ spectrum in octahedric sites. Moessbauer parameters complemented by other studies indicate illite is the predominant clay mineral. A trait of the parameters behaviour in presence of temperature is reported. (author)

  14. Climate change-induced heat risks for migrant populations working at brick kilns in India: a transdisciplinary approach

    Lundgren-Kownacki, Karin; Kjellberg, Siri M.; Gooch, Pernille; Dabaieh, Marwa; Anandh, Latha; Venugopal, Vidhya

    2018-03-01

    During the summer of 2015, India was hit by a scorching heat wave that melted pavements in Delhi and caused thousands of deaths, mainly among the most marginalized populations. One such group facing growing heat risks from both occupational and meteorological causes are migrant brick kiln workers. This study evaluates both current heat risks and the potential future impacts of heat caused by climate change, for the people working at brick kilns in India. A case study of heat stress faced by people working at brick kilns near Chennai, India, is the anchor point around which a transdisciplinary approach was applied. Around Chennai, the situation is alarming since occupational heat exposure in the hot season from March to July is already at the upper limits of what humans can tolerate before risking serious impairment. The aim of the study was to identify new pathways for change and soft solutions by both reframing the problem and expanding the solution space being considered in order to improve the quality of life for the migrant populations at the brick kilns. Technical solutions evaluated include the use of sun-dried mud bricks and other locally "appropriate technologies" that could mitigate the worsening of climate change-induced heat. Socio-cultural solutions discussed for empowering the people who work at the brick kilns include participatory approaches such as open re-localization, and rights-based approaches including the environmental sustainability and the human rights-based approach framework. Our analysis suggests that an integrative, transdisciplinary approach could incorporate a more holistic range of technical and socio-culturally informed solutions in order to protect the health of people threatened by India's brick kiln industry.

  15. Communication plan for windblown dust.

    2015-05-01

    Windblown dust events occur in Arizona, and blowing dust has been considered a contributing factor to serious crashes on the : segment of Interstate 10 (I10) between Phoenix and Tucson, as well as on other Arizona roadways. Arizonas dust events...

  16. 21 CFR 888.4200 - Cement dispenser.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement dispenser. 888.4200 Section 888.4200 Food... DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4200 Cement dispenser. (a) Identification. A cement dispenser is a nonpowered syringe-like device intended for use in placing bone cement (§ 888.3027) into...

  17. A cement based syntactic foam

    Li Guoqiang; Muthyala, Venkata D.

    2008-01-01

    In this study, a cement based syntactic foam core was proposed and experimentally investigated for composite sandwich structures. This was a multi-phase composite material with microballoon dispersed in a rubber latex toughened cement paste matrix. A trace amount of microfiber was also incorporated to increase the number of mechanisms for energy absorption and a small amount of nanoclay was added to improve the crystal structure of the hydrates. Three groups of cement based syntactic foams with varying cement content were investigated. A fourth group of specimens containing pure cement paste were also prepared as control. Each group contained 24 beam specimens. The total number of beam specimens was 96. The dimension of each beam was 30.5 cm x 5.1 cm x 1.5 cm. Twelve foam specimens from each group were wrapped with plain woven 7715 style glass fabric reinforced epoxy to prepare sandwich beams. Twelve cubic foam specimens, three from each group, with a side length of 5.1 cm, were also prepared. Three types of testing, low velocity impact test and four-point bending test on the beam specimens and compression test on the cubic specimens, were conducted to evaluate the impact energy dissipation, stress-strain behavior, and residual strength. Scanning electron microscope (SEM) was also used to examine the energy dissipation mechanisms in the micro-length scale. It was found that the cement based syntactic foam has a higher capacity for dissipating impact energy with an insignificant reduction in strength as compared to the control cement paste core. When compared to a polymer based foam core having similar compositions, it was found that the cement based foam has a comparable energy dissipation capacity. The developed cement based syntactic foam would be a viable alternative for core materials in impact-tolerant composite sandwich structures

  18. Crown and bridge cements: clinical applications.

    Bunek, Sabiha S; Powers, John M

    2012-12-01

    Cement selection can be confusing because factors such as substrate, the type of restoration, and patient needs must be considered. Some substrates require additional treatment before cementation. This article describes the most commonly used traditional crown and bridge cements (GI and RMGI) used for metal and metal-ceramic restorations, and resin cements used for all-ceramic restorations. Advantages, disadvantages, indications, and contraindications of cements have been reviewed. Recommended uses of cements for metal, ceramic, and laboratory composite restorations have been presented. General guidelines for surface treatment ot silica- and zirconia-based restorations when using resin cements have been discussed.

  19. Charcoal kiln sites, associated landscape attributes and historic forest conditions: DTM-based investigations in Hesse (Germany

    Marcus Schmidt

    2016-03-01

    Full Text Available Background An examination of the distribution of ancient charcoal kiln sites in the forest landscape seems to be worthwhile, since general trends in the selection of suitable kiln site locations in the past might become obvious. In this way forest landscape elements with a more intense usage by charcoal burning can be identified. By doing this, we can expect to gain information on the former condition and tree species composition of woodland. Investigations on the spatial distribution of charcoal kiln sites in relation to landscape attributes are sparse, however, probably due to the high on-site mapping effort. The outstanding suitability of LiDAR-derived digital terrain models (DTMs for the detection of charcoal kiln sites has been recently proved. Hence, DTM-based surveys of charcoal kiln sites represent a promising attempt to fill this research gap. Methods Based on DTM-based surveys, we analyzed the spatial distribution of charcoal kiln sites in two forest landscapes in the German federal state of Hesse: Reinhardswald and Kellerwald-Edersee National Park. In doing so, we considered the landscape attibutes "tree species composition", “water supply status”, “nutrient supply status”, “soil complex classes”, “altitude”, “exposition”, and “inclination”. Results We found that charcoal kiln sites were established preferably on hillside locations that provided optimal growing and regeneration conditions for European beech (Fagus sylvatica due to their acidic brown soils and sufficient water supply. These results are in line with instructions for the selection of appropriate kiln site locations, found in literature from the 18th to the 19th century. Conclusions We conclude that there were well-stocked, beech-dominated deciduous forest stands in northern Hesse before 1800, particularly at poorly accessible hillside locations. These large stocks of beech wood were utilized by the governments of the different Hessian territories

  20. Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production

    Cornelissen, Gerard; Pandit, Naba Raj; Taylor, Paul; Pandit, Bishnu Hari; Sparrevik, Magnus; Schmidt, Hans Peter

    2016-01-01

    Flame Curtain Biochar Kilns Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide) and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns), also avoiding use of external fuel for start-up. Biochar Characteristics A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57), average surface areas (11 to 215 m2 g-1), low EPA16—PAHs (2.3 to 6.6 mg kg-1) and high CECs (43 to 217 cmolc/kg)(average for all feedstocks, mainly woody shrubs) were obtained, in compliance with the European Biochar Certificate (EBC). Gas Emission Factors Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks); CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC) = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10) = 11 ± 15, total products of incomplete combustion (PIC) = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (p<0.05) lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2. Implications With benefits such as high quality biochar, low emission

  1. Dust in planetary nebulae

    Mathis, J.S.

    1978-01-01

    The author's review concentrates on theoretical aspects of dust in planetary nebulae (PN). He considers the questions: how much dust is there is PN; what is its composition; what effects does it have on the ionization structure, on the dynamics of the nebula. (Auth.)

  2. Toxicity of lunar dust

    Linnarsson, D.; Carpenter, J.; Fubini, B.; Gerde, P.; Loftus, D.; Prisk, K.; Staufer, U.; Tranfield, E.; van Westrenen, W.

    2012-01-01

    The formation, composition and physical properties of lunar dust are incompletely characterised with regard to human health. While the physical and chemical determinants of dust toxicity for materials such as asbestos, quartz, volcanic ashes and urban particulate matter have been the focus of

  3. Combustible dust tests

    The sugar dust explosion in Georgia on February 7, 2008 killed 14 workers and injured many others (OSHA, 2009). As a consequence of this explosion, OSHA revised its Combustible Dust National Emphasis (NEP) program. The NEP targets 64 industries with more than 1,000 inspections and has found more tha...

  4. Cement/slag chemistry studies

    Glasser, F.P.; Macphee, D.; Atkins, M.; Beckley, N.; Carson, S.O.; Wilding, C.R.; McHugh, G.

    1988-01-01

    The performance of cement-based matrices intended for radwaste immobilization is assessed. The long-term performance of the matrix is characterized by thermodynamic evaluation of experimental data. The results are presented in a general form, amenable to a range of specific formulations. The interaction of specific radwaste components with cements has been studied, using Iodine as an example. It occurs as both I - and IO 3 - species, but these differ sharply in sorption characteristics. The effect of ionizing radiation of the pH and E h of cement matrices is reported. (author)

  5. Cements in Radioactive Waste Disposal

    Glasser, F.P.

    2013-01-01

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  6. Cements in Radioactive Waste Disposal

    Glasser, F. P. [University of Aberdeen, Scotland (United Kingdom)

    2013-09-15

    The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

  7. Respirable dust measured downwind during rock dust application.

    Harris, M L; Organiscak, J; Klima, S; Perera, I E

    2017-05-01

    The Pittsburgh Mining Research Division of the U.S. National Institute for Occupational Safety and Health (NIOSH) conducted underground evaluations in an attempt to quantify respirable rock dust generation when using untreated rock dust and rock dust treated with an anticaking additive. Using personal dust monitors, these evaluations measured respirable rock dust levels arising from a flinger-type application of rock dust on rib and roof surfaces. Rock dust with a majority of the respirable component removed was also applied in NIOSH's Bruceton Experimental Mine using a bantam duster. The respirable dust measurements obtained downwind from both of these tests are presented and discussed. This testing did not measure miners' exposure to respirable coal mine dust under acceptable mining practices, but indicates the need for effective continuous administrative controls to be exercised when rock dusting to minimize the measured amount of rock dust in the sampling device.

  8. Lunar Dust Mitigation Screens

    Knutson, Shawn; Holloway, Nancy

    With plans for the United States to return to the moon, and establish a sustainable human presence on the lunar surface many issues must be successfully overcome. Lunar dust is one of a number of issues with the potential to create a myriad of problems if not adequately addressed. Samples of dust brought back from Apollo missions show it to be soft, yet sharp and abrasive. The dust consists of a variety of morphologies including spherical, angular blocks, shards, and a number of irregular shapes. One of the main issues with lunar dust is its attraction to stick to anything it comes in contact with (i.e. astronauts, equipment, habitats, etc.). Ionized radiation from the sun strikes the moon's surface and creates an electrostatic charge on the dust. Further, the dust harbors van der Waals forces making it especially difficult to separate once it sticks to a surface. During the Apollo missions, it was discovered that trying to brush the lunar dust from spacesuits was not effective, and rubbing it caused degradation of the suit material. Further, when entering the lunar module after moonwalks, the astronauts noted that the dust was so prolific inside the cabin that they inhaled and ingested it, causing at least one of them, Harrison "Jack" Schmidt, to report irritation of the throat and lungs. It is speculated that the dust could also harm an astronaut's nervous and cardiovascular systems, especially during an extended stay. In addition to health issues, the dust can also cause problems by scouring reflective coatings off of thermal blankets, and roughening surfaces of windows and optics. Further, panels on solar cells and photovoltaics can also be compromised due to dust sticking on the surfaces. Lunar dust has the capacity to penetrate seals, interfere with connectors, as well as mechanisms on digging machines, all of which can lead to problems and failure. To address lunar dust issues, development of electrostatic screens to mitigate dust on sur-faces is currently

  9. Does cement mantle thickness really matter?

    Caruana, J.

    2008-01-01

    The thickness of the cement mantle around the femoral component of total hip replacements is a contributing factor to aseptic loosening and revision. Nevertheless, various designs of stems and surgical tooling lead to cement mantles of differing thicknesses. This thesis is concerned with variability in cement thickness around the Stanmore Hip, due to surgical approach, broach size and stem orientation, and its effects on stress and cracking in the cement. The extent to which cement mantle thi...

  10. Energy and exergy analysis of an annular shaft kiln with opposite burners

    Rong, Wenjie; Li, Baokuan; Qi, Fengsheng; Cheung, Sherman C.P.

    2017-01-01

    Highlights: • An OBASK is investigated for the energy and exergy performance. • The energy and exergy efficiency of the OBASK is of 63.6% and 35.7%, respectively. • The exergy destruction accounts for 44.5% of the total exergy input. - Abstract: Annular shaft kilns with opposite burners (OBASK) has been widely adopted due to the advantages of cost saving and easy controlling. Nonetheless, compared with the traditional annular shaft kiln, the OBASK is not favorable in terms of thermal performance and energy efficiency. Aiming to improve the thermal performance, a comprehensive energy and exergy analysis of an OBASK has been conducted based on the actual operational data obtained from on-site measurements. For making a thorough thermal analysis of the OBASK, special attentions have been focused in considering magnesium decomposition reaction and moisture in limestone in the methodology. The energy and exergy efficiencies are determined to be 63.6% and 35.7%, respectively. The exergy destruction is 44.0% of total exergy input of which fuel combustion causes 56.6% of the exergy destruction. Furthermore, the effects of CaO and moisture contents in limestone on energy and exergy efficiencies are analyzed. The results have demonstrated the potential energy saving of the OBASK and identified three proposed energy conservation measures. Improvement and effect of the three proposed measures on the thermal performance are verified via further analysis.

  11. Thermal Behavior of Coal Used in Rotary Kiln and Its Combustion Intensification

    Qiang Zhong

    2018-04-01

    Full Text Available Pyrolysis and combustion behaviors of three coals (A, B, and C coals were investigated and their combustion kinetics were calculated by the Freeman–Carroll method to obtain quantitative insight into their combustion behaviors. Moreover, the effects of coal size, air flow, oxygen content, and heating rate on coal combustion behaviors were analyzed. Results showed that the three coals have a similar trend of pyrolysis that occurs at about 670 K and this process continuously proceeds along with their combustion. Combustion characteristics and kinetic parameters can be applied to analyze coal combustion behaviors. Three coals having combustion characteristics of suitable ignition temperature (745–761 K, DTGmax (14.20–15.72%/min, and burnout time (7.45–8.10 min were analyzed in a rotary kiln. Combustion kinetic parameters provide quantitative insights into coal combustion behavior. The suitable particle size for coal combustion in a kiln is that the content of less than 74 μm is 60% to 80%. Low activation energy and reaction order make coal, especially C coal, have a simple combustion mechanism, great reactivity, be easily ignited, and a low peak temperature in the combustion state. Oxygen-enrichment and high heating rates enhance coal combustion, increasing combustion intensity and peak value, thus shortening burnout time.

  12. CFD SIMULATION FOR DEMILITARIZATION OF RDX IN A ROTARY KILN BY THERMAL DECOMPOSITION

    SI H. LEE

    2017-06-01

    Full Text Available Demilitarization requires the recovery and disposal of obsolete ammunition and explosives. Since open burning/detonation of hazardous waste has caused serious environmental and safety problems, thermal decomposition has emerged as one of the most feasible methods. RDX is widely used as a military explosive due to its high melting temperature and detonation power. In this work, the feasible conditions under which explosives can be safely incinerated have been investigated via a rotary kiln simulation. To solve this problem, phase change along with the reactions of RDX has been incisively analyzed. A global reaction mechanism consisting of condensed phase and gas phase reactions are used in Computational Fluid Dynamics simulation. User Defined Functions in FLUENT is utilized in this study to inculcate the reactions and phase change into the simulation. The results divulge the effect of temperature and the varying amounts of gas produced in the rotary kiln during the thermal decomposition of RDX. The result leads to the prospect of demilitarizing waste explosives to avoid the possibility of detonation.

  13. Calcium Aluminate Cement Hydration Model

    Matusinović, T.

    2011-01-01

    Full Text Available Calcium aluminate cement (AC is a very versatile special cement used for specific applications. As the hydration of AC is highly temperature dependent, yielding structurally different hydration products that continuously alter material properties, a good knowledge of thermal properties at early stages of hydration is essential. The kinetics of AC hydration is a complex process and the use of single mechanisms models cannot describe the rate of hydration during the whole stage.This paper examines the influence of temperature (ϑ=5–20 °C and water-to-cement mass ratio (mH /mAC = 0.4; 0.5 and 1.0 on hydration of commercial iron-rich AC ISTRA 40 (producer: Istra Cement, Pula, Croatia, which is a part of CALUCEM group, Figs 1–3. The flow rate of heat generation of cement pastes as a result of the hydration reactions was measured with differential microcalorimeter. Chemically bonded water in the hydrated cement samples was determined by thermo-gravimetry.Far less heat is liberated when cement and water come in contact for the first time, Fig. 1, than in the case for portland cement (PC. Higher water-to-cement ratio increases the heat evolved at later ages (Fig. 3 due to higher quantity of water available for hydration. A significant effect of the water-to-cement ratio on the hydration rate and hydration degree showed the importance of water as being the limiting reactant that slows down the reaction early. A simplified stoichiometric model of early age AC hydration (eq. (8 based on reaction schemes of principal minerals, nominally CA, C12A7 and C4AF (Table 1, was employed. Hydration kinetics after the induction period (ϑ < 20 °C had been successfully described (Fig. 4 and Table 2 by a proposed model (eq. (23 which simultaneously comprised three main mechanisms: nucleation and growth, interaction at phase boundary, and mass transfer. In the proposed kinetic model the nucleation and growth is proportional to the amount of reacted minerals (eq

  14. Rheological measurements on cement grouts

    Dalton, M.J.

    1986-06-01

    This report describes the techniques which have been developed at Winfrith for assessing the rheological properties of cement grouts. A discussion of the theory of rheology and its application to cement is given and the methodology for calibrating a special paddle measuring system for a commercial viscometer is described. The use of the system for determining flow curves, equilibrium viscosity, viscosity as a function of shearing time and structure changes is also discussed. (author)

  15. Cement pulmonary embolism after vertebroplasty.

    Sifuentes Giraldo, Walter Alberto; Lamúa Riazuelo, José Ramón; Gallego Rivera, José Ignacio; Vázquez Díaz, Mónica

    2013-01-01

    In recent years, the use of vertebral cementing techniques for vertebroplasty and kyphoplasty has spread for the treatment of pain associated with osteoporotic vertebral compression fractures. This is also associated with the increased incidence of complications related with these procedures, the most frequent being originated by leakage of cementation material. Cement can escape into the vertebral venous system and reach the pulmonary circulation through the azygous system and cava vein, producing a cement embolism. This is a frequent complication, occurring in up to 26% of patients undergoing vertebroplasty but, since most patients have no clinical or hemodynamical repercussion, this event usually goes unnoticed. However, some serious, and even fatal cases, have been reported. We report the case of a 74-year-old male patient who underwent vertebroplasty for persistent pain associated with osteoporotic L3 vertebral fracture and who developed a cement leak into the cava vein and right pulmonary artery during the procedure. Although he developed a pulmonary cement embolism, the patient remained asymptomatic and did not present complications during follow-up. Copyright © 2012 Elsevier España, S.L. All rights reserved.

  16. Calcium Orthophosphate Cements and Concretes

    Sergey V. Dorozhkin

    2009-03-01

    Full Text Available In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA or brushite, sometimes blended with unreacted particles and other phases. As both CDHA and brushite are remarkably biocompartible and bioresorbable (therefore, in vivo they can be replaced with newly forming bone, calcium orthophosphate cements represent a good correction technique for non-weight-bearing bone fractures or defects and appear to be very promising materials for bone grafting applications. Besides, these cements possess an excellent osteoconductivity, molding capabilities and easy manipulation. Furthermore, reinforced cement formulations are available, which in a certain sense might be described as calcium orthophosphate concretes. The concepts established by calcium orthophosphate cement pioneers in the early 1980s were used as a platform to initiate a new generation of bone substitute materials for commercialization. Since then, advances have been made in the composition, performance and manufacturing; several beneficial formulations have already been introduced as a result. Many other compositions are in experimental stages. In this review, an insight into calcium orthophosphate cements and concretes, as excellent biomaterials suitable for both dental and bone grafting application, has been provided.

  17. Quantifying Anthropogenic Dust Emissions

    Webb, Nicholas P.; Pierre, Caroline

    2018-02-01

    Anthropogenic land use and land cover change, including local environmental disturbances, moderate rates of wind-driven soil erosion and dust emission. These human-dust cycle interactions impact ecosystems and agricultural production, air quality, human health, biogeochemical cycles, and climate. While the impacts of land use activities and land management on aeolian processes can be profound, the interactions are often complex and assessments of anthropogenic dust loads at all scales remain highly uncertain. Here, we critically review the drivers of anthropogenic dust emission and current evaluation approaches. We then identify and describe opportunities to: (1) develop new conceptual frameworks and interdisciplinary approaches that draw on ecological state-and-transition models to improve the accuracy and relevance of assessments of anthropogenic dust emissions; (2) improve model fidelity and capacity for change detection to quantify anthropogenic impacts on aeolian processes; and (3) enhance field research and monitoring networks to support dust model applications to evaluate the impacts of disturbance processes on local to global-scale wind erosion and dust emissions.

  18. Spirit Feels Dust Gust

    2007-01-01

    On sol 1149 (March 28, 2007) of its mission, NASA's Mars Exploration Rover Spirit caught a wind gust with its navigation camera. A series of navigation camera images were strung together to create this movie. The front of the gust is observable because it was strong enough to lift up dust. From assessing the trajectory of this gust, the atmospheric science team concludes that it is possible that it passed over the rover. There was, however, no noticeable increase in power associated with this gust. In the past, dust devils and gusts have wiped the solar panels of dust, making it easier for the solar panels to absorb sunlight.

  19. Low pH Cements

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  20. Low pH Cements

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  1. Development of cement material using inorganic additives

    Toyohara, Masumitsu; Satou, Tatsuaki; Wada, Mikio; Ishii, Tomoharu; Matsuo, Kazuaki.

    1997-01-01

    Inorganic admixtures to enhance the fluidity of cement material was developed. These admixtures turned into easy to immobilize the miscellaneous radioactive waste using cement material. It was found that the ζ potential of cement particles was directly proportional to the content of the inorganic admixtures in cement paste and the particles of cement were dispersed at the high ζ potential. The condensed sodium phosphate, which was the main component of the inorganic admixtures, retarded the dissolution of Ca 2+ ion from the cement, and generated the colloids by incorporating dissolved Ca 2+ ion. The cement material containing the inorganic admixtures was found to have the same mechanical strength and adsorption potential of radionuclides in comparison to normal cement materials. It was confirmed that the cement material containing the inorganic admixture was effectively filled gaps of miscellaneous radioactive waste. (author)

  2. Development of high-performance blended cements

    Wu, Zichao

    2000-10-01

    This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

  3. Use of lignite in the production of sponge iron and processing of waste oxides in rotary kilns

    Eichberger, H; Schnabel, W; Serbent, H

    1978-11-01

    Based on a study of the situation of fossil energy reserves, processes are described in which non-coking coals, in particular lignite, are used for reduction in the rotary kiln, i.e. for sponge iron production and for zinc volatilization from waste oxides).

  4. Hydrogen fluoride effects on local mung bean and maize cereal crops from peri-urban brick kilns in south asia

    Ahmad, M.N.; Ahmad, S.S.; Zia, A.; Iqbal, M.S.; Shah, H.; Mian, A.A.; Shah, R.U.

    2014-01-01

    Increased urbanisation throughout South Asia has increased the number and output of the brick kilns that typically surround major cities, but the environmental and health impacts of their atmospheric emissions are poorly understood in Pakistan. We report the negative effects of hydrogen fluoride

  5. THE FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A VENTURI/PACKED COLUMN SCRUBBER - VOLUME II: APPENDICES

    A 5-week series of pilot-scale incineration tests, employing a synthetic waste feed, was performed at the U.S. Environmental Protection Agency's Incineration Research Facility to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with a venturi scrubber/p...

  6. Thermodynamic analysis of the selective chlorination of electric arc furnace dust

    Pickles, C.A.

    2009-01-01

    The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

  7. Thermodynamic analysis of the selective chlorination of electric arc furnace dust

    Pickles, C.A., E-mail: pickles-c@mine.queensu.ca [Department of Mining Engineering, Queen' s University, Kingston, Ontario, K7L 3N6 (Canada)

    2009-07-30

    The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

  8. Thermodynamic analysis of the selective chlorination of electric arc furnace dust.

    Pickles, C A

    2009-07-30

    The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

  9. Air Pollutant Emissions Projections for the Cement and Steel Industry in China and the Impact of Emissions Control Technologies

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Khanna, Nina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-03-01

    scenario showed significantly lower PM emissions for the cement industry, reaching to 1.7 million tons of PM in 2050, which is less than half of that in the other two scenarios. The Advanced EOP scenario also has the lowest SO2 emissions for the cement industry in China, reaching to 212,000 tons of SO2 in 2050, which is equal to 40 percent of the SO2 emissions in the Advanced scenario and 30 percent of the emissions in the Base Case scenario. The SO2 emission is mainly caused by fuel (coal) burning in cement kiln or steel processes. For the steel industry, the SO2 emissions of the Advanced EOP scenario are significantly lower than the other scenarios, with emissions declining to 323,000 tons in 2050, which is equal to 21 percent and 17 percent of the emissions of Advanced and Base Case scenarios in 2050, respectively. Results of the economic analysis show that for the Chinese cement industry, end-of-pipe PM control technologies have the lowest abatement cost per ton of PM reduced, followed by product change measures and energy efficiency measures, respectively. In summary, in order to meet Chinese national and regional air quality standards, best practice end-of-pipe emissions control technologies must be installed in both cement and steel industry and it must be supplemented by implementation of energy efficiency technologies and reduction of cement and steel production through structural change in industry.

  10. Dust Fertilization of the Western Atlantic Biota: a Biochemical Model

    Holmes, C. W.

    2017-12-01

    Every year an estimated 50 million tons of African dust reaches the Western Atlantic. This dust is composed of quartz sand, clay, and a mixture of quartz and clay particles agglutinated with micronutrient enriched ferruginous cement. However, whether it is friend or foe to biochemical systems is a matter of conjecture. Corals are ideal recorders of changing conditions as the layers can be dated so that the record of chemical changes is easily assessed. There is extensive shallow-and deep water coral development bordering the Florida Straits. The changes in trace element chemistry within these corals show a positive relationship with the African dust record. Recently, it has been demonstrated that many of the metals contained within the dust are necessary micronutrients in the fertilization of plankton. Using the results of these studies, a biochemical model has been constructed. This model suggests a path from inorganic dust through microbial transformation to micronutrient enzymes (i.e. Cd-enriched carbonic anahydrase) and carbonate precipitation on the Bahamian Banks. It is estimated that more than ten million metric tons of this fine, metal-rich sediment is formed each year. However, for much of this sediment, its deposition is temporary, as it is transported into the Florida Straits yearly by tropical cyclones. This metal-enriched fine carbonate becomes nutrients for phytoplankton, providing food for the corals, both shallow and deep.

  11. Design and manufacture of X-ray analyser of CaO, Fe2O3, SiO2 and Al2O3, investment opportunity of Vietnam cement factories

    Nguyen Thanh Tuy; Luong Duc Long

    2008-01-01

    Cement is produced by heating naturally occurring raw materials containing the required oxides in kiln, which results in a product called clinker. To obtain the finished cement, the clinker is then ground together with gypsum, which controls setting properties, to a fine powder. Portland cement is a mixture of compounds formed from the oxides of Ca(CaO), Si(SiO 2 ), Al(Al 2 O 3 ), and Fe(Fe 2 O 3 ). In addition to these four main constituents it also contains smaller amounts of MgO, K 2 O, SO 3 , etc. Effective process control of cement is important to ensure high quality of the product. Traditionally wavelength dispersive x-ray fluorescence (WDXRF) spectrometers are used for cement quality control at the modern cement factories. The XRF-NCS02 is a compact energy dispersive X-ray fluorescence (EDXRF) analyzer. These spectrometers also are used for cement quality control at the small size cement plant. Product description: The XRF-NCS02 , table-top cement analyzer is a computer-based EDXRF spectrometer. The high efficiency and high resolution Si PIN detector is coupled to a 4096 channel MCA for data collection. The special low-power x-ray tube of the system requires no cooling and obligates the need for radioisotopes, as commonly found on such instruments. Computer: Compatible notebook or desktop PC, Pentium processor with CD-ROM. Software: XRF - NCS02 software for quantitative analysis; Interactive, operation under Windows XP. Installation: dimensions 500x380x300 mm (W x D x H); weight: 10 kg. (author)

  12. Polymer-cement interactions towards improved wellbore cement fracture sealants

    Beckingham, B. S.; Iloejesi, C.; Minkler, M. J.; Schindler, A. K.; Beckingham, L. E.

    2017-12-01

    Carbon capture, utilization, and storage (CCUS) in deep geologic formations is a promising means of reducing point source emissions of CO2. In these systems, CO2 is captured at the source and then injected to be utilized (eg. in enhanced oil recovery or as a working fluid in enhanced geothermal energy plants) or stored in geologic formations such as depleted oil and gas reservoirs or saline aquifers. While CCUS in subsurface systems could aid in reducing atmospheric CO2 emissions, the potential for CO2 leakage from these systems to overlying formations remains a major limitation and poses a significant risk to the security of injected CO2. Thus, improved materials for both initial wellbore isolation and repairing leakage pathways that develop over time are sought. One approach for the repair of cement fractures in wellbore (and other) systems is the injection of polymer materials into the fracture with a subsequent environmentally dependent (temperature, pressure, pH, etc.) densification or solidification. Here, we aim to investigate novel polymer materials for use to repair leaking wellbores in the context of CCUS. We synthesize and fully characterize a series of novel polymer materials and utilize a suite of analysis techniques to examine polymer-cement interactions at a range of conditions (namely temperature, pressure and pH). Initial findings will be leveraged to design novel polymer materials for further evaluation in polymer-cement composite cores, cement fracture healing, and the aging behavior of healed cements.

  13. Galactic dust and extinction

    Lyngaa, G.

    1979-01-01

    The ratio R between visual extinction and colour excess, is slightly larger than 3 and does not vary much throughout our part of the Galaxy. The distribution of dust in the galactic plane shows, on the large scale, a gradient with higher colour excesses towards l=50 0 than towards l=230 0 . On the smaller scale, much of the dust responsible for extinction is situated in clouds which tend to group together. The correlation between positions of interstellar dust clouds and positions of spiral tracers seems rather poor in our Galaxy. However, concentrated dark clouds as well as extended regions of dust show an inclined distribution similar to the Gould belt of bright stars. (Auth.)

  14. Structural ceramics containing electric arc furnace dust

    Stathopoulos, V.N., E-mail: vasta@teihal.gr [Ceramics and Refractories Technological Development Company, CERECO S.A., 72nd km Athens Lamia National Road, P.O. Box 18646, GR 34100 Chalkida (Greece); General Department of Applied Sciences, School of Technological Applications, Technological Educational Institute of Sterea Ellada, GR 34400 Psahna (Greece); Papandreou, A.; Kanellopoulou, D.; Stournaras, C.J. [Ceramics and Refractories Technological Development Company, CERECO S.A., 72nd km Athens Lamia National Road, P.O. Box 18646, GR 34100 Chalkida (Greece)

    2013-11-15

    Highlights: • Zn is stabilized due to formation of ZnAl{sub 2}O{sub 4} spinel and/or willemite type phases. • EAFD/clay fired mixtures exhibit improved mechanical properties. • Hollow bricks were successfully fabricated from the mixtures studied. • Laboratory articles and scaled up bricks found as environmentally inert materials. -- Abstract: In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in

  15. Structural ceramics containing electric arc furnace dust.

    Stathopoulos, V N; Papandreou, A; Kanellopoulou, D; Stournaras, C J

    2013-11-15

    In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in an increase of mechanical strength. Moreover, leaching tests performed according to the Europeans standards on the EAFD-block samples showed that the quantities of heavy metals leached from crushed blocks were within the regulatory limits. Thus the EAFD-blocks can be regarded as material of no environmental concern. Copyright © 2013 Elsevier B

  16. Structural ceramics containing electric arc furnace dust

    Stathopoulos, V.N.; Papandreou, A.; Kanellopoulou, D.; Stournaras, C.J.

    2013-01-01

    Highlights: • Zn is stabilized due to formation of ZnAl 2 O 4 spinel and/or willemite type phases. • EAFD/clay fired mixtures exhibit improved mechanical properties. • Hollow bricks were successfully fabricated from the mixtures studied. • Laboratory articles and scaled up bricks found as environmentally inert materials. -- Abstract: In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in an

  17. Radioisotope dust pollution monitor

    Szepke, R.; Harasimczuk, J.; Dobrowiecki, J.

    1990-01-01

    Measuring principles and specification of two dust monitors: station-type AMIZ and portable-type PIK-10 for ambient air pollution are presented. The first one, a fully automatic instrument is destined for permanent monitoring of air pollution in preset sampling time from .25 to 24 hours. The second one was developed as a portable working model. Both instruments display their results in digital form in dust concentration units. (author)

  18. Dust devil generation

    G Onishchenko, O; A Pokhotelov, O; Horton, W; Stenflo, L

    2014-01-01

    The equations describing axi-symmetric nonlinear internal gravity waves in an unstable atmosphere are derived. A hydrodynamic model of a dust devil generation mechanism in such an atmosphere is investigated. It is shown that in an unstably stratified atmosphere the convective plumes with poloidal motion can grow exponentially. Furthermore, it is demonstrated that these convective plumes in an atmosphere with weak large scale toroidal motion are unstable with respect to three-dimensional dust devil generation. (papers)

  19. KILN METAR

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is a routine scheduled observation and is the primary observation code used in the United States to satisfy requirements for reporting surface meteorological...

  20. Seepage/Cement Interactions

    Carpenter, D.

    2000-01-01

    The Development Plan (CRWMS M andO 1999a) pertaining to this task defines the work scopes and objectives for development of various submodels for the Physical and Chemical Environment Abstraction Model for TSPA-LA. The Development Plan (CRWMS M andO 1999a) for this specific task establishes that an evaluation be performed of the chemical reactions between seepage that has entered the drift and concrete which might be used in the repository emplacement drifts. The Development Plan (CRWMS M andO 1999a) then states that the potential effects of these water/grout reactions on chemical conditions in the drift be assessed factoring in the influence of carbonation and the relatively small amount of grout. This task is also directed at: (1) developing a conceptualization of important cement/seepage interactions and potential impacts on EBS performance, (2) performing a screening analysis to assess the importance of cement/seepage interactions. As the work progresses and evolves on other studies, specifically the Engineered Barrier System: Physical and Chemical Environment (P andCE) Model (in progress), many of the issues associated with items 1 and 2, above, will be assessed. Such issues include: (1) Describing the mineralogy of the specified cementitious grout and its evolution over time. (2) Describing the composition of the water before contacting the grout. (3) Developing reasonable upper-bound estimates for the composition of water contacting grout, emphasizing pH and concentrations for anions such as sulfate. (4) Evaluating the equilibration of cement-influenced water with backfill and gas-phase CO 2 . (5) Developing reasonable-bound estimates for flow rate of affected water into the drift. The concept of estimating an ''upper-bound'' range for reaction between the grout and the seepage, particularly in terms of pH is based on equilibrium being established between the seepage and the grout. For example, this analysis can be based on equilibrium being established as