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04684 Role of interfacial phenomena in fine coal dewatering
01
Solid fuels (preparation)
Improved approaches for dewaterlng of fine coal 96104669 Yang! J. et al., Proc. Process. Hydrophobic Miner. Fine Coal, UBCM&r11 Bi-Annu. Int. Symp. Fundam. Minera. Process, Canadian Inst. of Mining, Metallurgy & Petroleum, 1995, 503-511. The removal of moisture from ultrafine clean coal (minus 100 mesh) to below 20% levels is difficult using conventional dewatering equipment. The paper describes a couple of dewatering approaches which are effective in providing filter cakes containing less than 20% moisture.
improved efficiency of coal cleaning using a flota96104670 tion-regrindlng~flotation process Polat. H. and Chander. S. Proc. Process. Hvdroohobic Miner. Fine Coal, UBC:McGill Bi-Annul Int. Symp. Fundam.. M&era. Process, Canadian Inst. of Mining, Metallurgy & Petroleum, 1995, 179-189. Several approaches have been suggested in the past lo improve the flotation cleaning of coal at fine sizes. In this investigation, different circuit configurations are compared to show that the choice of the most effective approach is a function of coal sype. Some coals could be further cleaned by recleaning the froth products. For such coals, column flotation is likely to be very beneficial. For other coals, regrinding the coarse coal flotation product prior lo flotation improved the grade. This approach gave better performance compared to fine rinding the feed, followed by its flotation. Presents the results of four dlf+ erent coal samples.
96104671 The influence of mineral matter on the separation of amorphous marine kerogens using density gradient centrifugation Hartners. W. A. Ora. Geochem., 1995. 23, (81. 777-784. The :ap& describes cow D-gradient cer&ifugahon (DGC) was applied to three amorphous marine kerogens. SEM-energy dispersive spectroscopic analysis revealed petrographic distinct macerals between fractions of low and high density. However, these microscopic observations were not accompanied by chemical differences, as revealed by Curie-point pyrolysis.
Kinetics of heat treatment of Kansk-Achinsk Basin 96104672 brown coals Boiko, E. A. Khim. Tverd. Topl. (Moscow), 1995, (5), 31-37. (In Russian) Describes a method of complex thermal analysis of coal. Processes of moisture evaporation, devolatilization with separate analyses of tar and gas evolution. and reaction of solid residue with 0 of air were studied.
96104673 Method for dewatering coal tailings using DADMAC/vinyl trialkoxysilane copolymers as a coagulant Kerr, E. M. and Ramesh, M. (Assigned to) Nalco Chemxal Co., US Pal. L&.5,476,522, Dec. 1995. Describes a method where coal tailines are concentrated and coal oroducts dewatered using a copolymer of dia~lyldimethylammonium halide and a vinyl alkoxysilane, preferably a copolymer of diallyldime~hylammonium chloride and vinlytrimethoxysilane as a coagulant.
Mlcroblologlcal desulfurization of coal 96104674 Twardowska, I. Przegl. Gorn., 1995, 51, (lo), 29-33. (In Polish) Presents the current state of research and development of desulphurization of raw coal (fines), a subject of vital importance for environmental protection. Particular advantages of the biological method for coal desulphurization are indicated, such as low energy consumption for the biochemical reactions and for the chemical reagents, which are in addition cheap and easily available. Among the principal advantages is the zero coal loss and absence of waste with moreover high efficiency of pyrite sulphur removal.
Oxidative pretreatments for the enhanced removal 96104670 of organic sulfur from coal Palmer, S. R. et al., Coal&i. Technol., 1995, 24, (2), 1713-1716. The paper compares the removal of organic sulphur from coal by air oxidation with base and MeOH compared with oxidation with more expensive oxidizing agents. Inexpensive oxidants appeared to be just as good as, if not superior to expensive oxidizing agents for the oxidative pretreatment step in desulphurization. The ath of sulfur during the blo-oxidation of pyrite 96104679 by Thlobaclllus Perrooxidans Rojas-Chapana, J. A. et al., Fuel, Jun. 1996, 75, (8), 923-930. The detection of colloidal sulphur with dimensions of 20 (sometimes up to 70) to 4 nm as intermediates of sulphide bio-oxidation by Thiobacillus ferrooxidans presents new possibiliries for the exploration of the leaching mechanism of inoreanic sulohides and for the use of sulohur in bacterial metabolism. The liberation of sulphide-S from a crystallized compound in an interfacial reaction, the formation and stabilization of colloids (by biological macromolecules) in an organic capsule around the bacterial cell and the life cycle of colloids during the leaching, including their final consumption, are discussed. An illustration is provided explaining the generation, stability and metabolism of sulphur from pyrite. 96104600 Possibilities of raising the rate of fine coal flotation Rubinstein, J. B. er al., Proc. Process. Hydrophobic Miner. Fine Coal, UBC-McGill Bi-Annu. Int. Symp. Fundam. Minera. Process, Canadian Inst. of Mining. Metallurgy & Petroleum, 1995, 165-178. Following fine grinding, the physical and physico-chemical properties of coal oartlcles chance: free macroradicals are formed. the average size of carbdn lavers decreases. the orocess of structure amorbhization &initiated. the aromitic constituenis are&transformed, and the probortion of disordered carbon in the side chains increases. As a result the adsorption ability of the coal particles increases. A series of tests conducted with narrow s&e fractions revealed their floatabilitv and the effect of fines content on the flotation response. The flotability distribution function was obtained using different reagents. The results demonstrated a high efficiency of the modified methods which include selective coagulation, selective flocculation and oil agglomeration. Prevention of coal selfignition by lowering its initial 96/04661 temperature Portola, V. A. Bezop. Tr. Prom-k., 1995, (6), 29-30. (In Russian) Discusses how the endogenic fires due 10 selfignition of coals can be prevented by lowering the oxygen concentration in the air and oxidation rate constant. The energy of interacting components must be reduced to decrease the amount of reacting oarticles and enerev release. The enerev of interactin p components can be-r‘cduced by prelimyiary cooling of the-ioal pile and dtermg air by using low-temperature heat-transfer agents. Discusses the dependence of the heat released from the coal during initial and low temperafures on the temperature drop during cooling. _ 96104682 Recent advances In separatlng and characterlzlng single coal macerals Crelling, J. C. and Bensley, D. F. Coal Sci. Technol., 1995, 1, 235-238. Discusses the methods for separation and characterization of individual coal macerals. Also discusses the cut point determination, acid demineralization, cryogenic treatment, semicontinuous centrifugation, rotational polarization reflectance, and fluorescence spectral characterization. Research on the thermal strength of dyad gas oven 96104683 brlquet Xu, D. el al., Huanjing Huaxue, 1996, 15, (2), 151-154. (In Chinese) Describes a study of the thermal strength of briquettes during coking.
Operation of coal pulverizing system with ball In crushing of low-grade anthracite P. P. Energ. Elektrif: (Kiev), 1995, (3), 10-12. (In Russian) coal pulverization system with fuel oil furnace-dryer, coal system with a boiler and gas heater, and closed loop coal system with a boiler.
Role of lnterfaclal phenomena In flne coal 96104684 dewaterlng Xu. 2. el al.. Proc. Process. Hvdroohobic Miner. Fine Coal, UBC-McGill Bi-Annu. Int; Symp. Fundam. kinera. Process, Canadian Inst. of Mining, Metallurgy & Petroleum, 1995, 513-525. Control of interfacial phenomena for improved fine coal filtration rate and dewatering efficiency is an attractive approach due to its great flexibility. However, the complex nature of interfacial phenomena in fine coal dewatering makes it a challenge to derive practical applications. In this namer. the filtration oerformance of fine coal slurrv was analvzed bv considering the filtration as a process of fluid flowing through capillary channels formed from the packing of fine coal particles. The performance of filtration was evaluated by the filtration rate and the moisture content of filter cake attainable. The.former determines the throughput and the latter determines the quality of final product of dewatering.
Organic sulfur removal from coal by rapid pyroly96104677 81s with alkali leaching and denslty separation Sugawara, K. er a/., Coal Sci. Technol., 1995, 24, (2). 1709-1712. High-temperature alkali treatment with KOH was combined with rapid pyrolysis in a free-fall reactor to successfully reduce the organic sulphur content in coal fractions separated by density differences by float-sink processes.
Roll-press brlquetting 96104685 Komarek, R. Mining Mug., Jun. 1996, 174, (6), 356, 358, 360. Discusses the compacting of mineral products into briquettes which is worrh considering for a number of reasons. Briquetting increases bulk density for easier handling, shipping or disposal; prevents caking or bridging insilos, hoppers and metering equipment; reduces dusting and segregation of fines in handling; improves remelt yields: and, in the case of fuels, improves burning characieristics. .
NO, reduction by coal brlquets 96104676 Garcia-Garcia, A. el al., Coal Sci. Technol., 1995, 24, (2), 1787-1790. Describes how fuel briquets were prepared using humic acids as a binding agent which also functioned as a carbon-based reducing agent lo reduce NO, emissions upon combustion.
96104676 drum mills Kucherenko, Describes a pulverization pulverization
334
Fuel and Energy
Abstracts
September
1996
Solid fuels (preparation)
Improved approaches for dewaterlng of fine coal 96104669 Yang! J. et al., Proc. Process. Hydrophobic Miner. Fine Coal, UBCM&r11 Bi-Annu. Int. Symp. Fundam. Minera. Process, Canadian Inst. of Mining, Metallurgy & Petroleum, 1995, 503-511. The removal of moisture from ultrafine clean coal (minus 100 mesh) to below 20% levels is difficult using conventional dewatering equipment. The paper describes a couple of dewatering approaches which are effective in providing filter cakes containing less than 20% moisture.
improved efficiency of coal cleaning using a flota96104670 tion-regrindlng~flotation process Polat. H. and Chander. S. Proc. Process. Hvdroohobic Miner. Fine Coal, UBC:McGill Bi-Annul Int. Symp. Fundam.. M&era. Process, Canadian Inst. of Mining, Metallurgy & Petroleum, 1995, 179-189. Several approaches have been suggested in the past lo improve the flotation cleaning of coal at fine sizes. In this investigation, different circuit configurations are compared to show that the choice of the most effective approach is a function of coal sype. Some coals could be further cleaned by recleaning the froth products. For such coals, column flotation is likely to be very beneficial. For other coals, regrinding the coarse coal flotation product prior lo flotation improved the grade. This approach gave better performance compared to fine rinding the feed, followed by its flotation. Presents the results of four dlf+ erent coal samples.
96104671 The influence of mineral matter on the separation of amorphous marine kerogens using density gradient centrifugation Hartners. W. A. Ora. Geochem., 1995. 23, (81. 777-784. The :ap& describes cow D-gradient cer&ifugahon (DGC) was applied to three amorphous marine kerogens. SEM-energy dispersive spectroscopic analysis revealed petrographic distinct macerals between fractions of low and high density. However, these microscopic observations were not accompanied by chemical differences, as revealed by Curie-point pyrolysis.
Kinetics of heat treatment of Kansk-Achinsk Basin 96104672 brown coals Boiko, E. A. Khim. Tverd. Topl. (Moscow), 1995, (5), 31-37. (In Russian) Describes a method of complex thermal analysis of coal. Processes of moisture evaporation, devolatilization with separate analyses of tar and gas evolution. and reaction of solid residue with 0 of air were studied.
96104673 Method for dewatering coal tailings using DADMAC/vinyl trialkoxysilane copolymers as a coagulant Kerr, E. M. and Ramesh, M. (Assigned to) Nalco Chemxal Co., US Pal. L&.5,476,522, Dec. 1995. Describes a method where coal tailines are concentrated and coal oroducts dewatered using a copolymer of dia~lyldimethylammonium halide and a vinyl alkoxysilane, preferably a copolymer of diallyldime~hylammonium chloride and vinlytrimethoxysilane as a coagulant.
Mlcroblologlcal desulfurization of coal 96104674 Twardowska, I. Przegl. Gorn., 1995, 51, (lo), 29-33. (In Polish) Presents the current state of research and development of desulphurization of raw coal (fines), a subject of vital importance for environmental protection. Particular advantages of the biological method for coal desulphurization are indicated, such as low energy consumption for the biochemical reactions and for the chemical reagents, which are in addition cheap and easily available. Among the principal advantages is the zero coal loss and absence of waste with moreover high efficiency of pyrite sulphur removal.
Oxidative pretreatments for the enhanced removal 96104670 of organic sulfur from coal Palmer, S. R. et al., Coal&i. Technol., 1995, 24, (2), 1713-1716. The paper compares the removal of organic sulphur from coal by air oxidation with base and MeOH compared with oxidation with more expensive oxidizing agents. Inexpensive oxidants appeared to be just as good as, if not superior to expensive oxidizing agents for the oxidative pretreatment step in desulphurization. The ath of sulfur during the blo-oxidation of pyrite 96104679 by Thlobaclllus Perrooxidans Rojas-Chapana, J. A. et al., Fuel, Jun. 1996, 75, (8), 923-930. The detection of colloidal sulphur with dimensions of 20 (sometimes up to 70) to 4 nm as intermediates of sulphide bio-oxidation by Thiobacillus ferrooxidans presents new possibiliries for the exploration of the leaching mechanism of inoreanic sulohides and for the use of sulohur in bacterial metabolism. The liberation of sulphide-S from a crystallized compound in an interfacial reaction, the formation and stabilization of colloids (by biological macromolecules) in an organic capsule around the bacterial cell and the life cycle of colloids during the leaching, including their final consumption, are discussed. An illustration is provided explaining the generation, stability and metabolism of sulphur from pyrite. 96104600 Possibilities of raising the rate of fine coal flotation Rubinstein, J. B. er al., Proc. Process. Hydrophobic Miner. Fine Coal, UBC-McGill Bi-Annu. Int. Symp. Fundam. Minera. Process, Canadian Inst. of Mining. Metallurgy & Petroleum, 1995, 165-178. Following fine grinding, the physical and physico-chemical properties of coal oartlcles chance: free macroradicals are formed. the average size of carbdn lavers decreases. the orocess of structure amorbhization &initiated. the aromitic constituenis are&transformed, and the probortion of disordered carbon in the side chains increases. As a result the adsorption ability of the coal particles increases. A series of tests conducted with narrow s&e fractions revealed their floatabilitv and the effect of fines content on the flotation response. The flotability distribution function was obtained using different reagents. The results demonstrated a high efficiency of the modified methods which include selective coagulation, selective flocculation and oil agglomeration. Prevention of coal selfignition by lowering its initial 96/04661 temperature Portola, V. A. Bezop. Tr. Prom-k., 1995, (6), 29-30. (In Russian) Discusses how the endogenic fires due 10 selfignition of coals can be prevented by lowering the oxygen concentration in the air and oxidation rate constant. The energy of interacting components must be reduced to decrease the amount of reacting oarticles and enerev release. The enerev of interactin p components can be-r‘cduced by prelimyiary cooling of the-ioal pile and dtermg air by using low-temperature heat-transfer agents. Discusses the dependence of the heat released from the coal during initial and low temperafures on the temperature drop during cooling. _ 96104682 Recent advances In separatlng and characterlzlng single coal macerals Crelling, J. C. and Bensley, D. F. Coal Sci. Technol., 1995, 1, 235-238. Discusses the methods for separation and characterization of individual coal macerals. Also discusses the cut point determination, acid demineralization, cryogenic treatment, semicontinuous centrifugation, rotational polarization reflectance, and fluorescence spectral characterization. Research on the thermal strength of dyad gas oven 96104683 brlquet Xu, D. el al., Huanjing Huaxue, 1996, 15, (2), 151-154. (In Chinese) Describes a study of the thermal strength of briquettes during coking.
Operation of coal pulverizing system with ball In crushing of low-grade anthracite P. P. Energ. Elektrif: (Kiev), 1995, (3), 10-12. (In Russian) coal pulverization system with fuel oil furnace-dryer, coal system with a boiler and gas heater, and closed loop coal system with a boiler.
Role of lnterfaclal phenomena In flne coal 96104684 dewaterlng Xu. 2. el al.. Proc. Process. Hvdroohobic Miner. Fine Coal, UBC-McGill Bi-Annu. Int; Symp. Fundam. kinera. Process, Canadian Inst. of Mining, Metallurgy & Petroleum, 1995, 513-525. Control of interfacial phenomena for improved fine coal filtration rate and dewatering efficiency is an attractive approach due to its great flexibility. However, the complex nature of interfacial phenomena in fine coal dewatering makes it a challenge to derive practical applications. In this namer. the filtration oerformance of fine coal slurrv was analvzed bv considering the filtration as a process of fluid flowing through capillary channels formed from the packing of fine coal particles. The performance of filtration was evaluated by the filtration rate and the moisture content of filter cake attainable. The.former determines the throughput and the latter determines the quality of final product of dewatering.
Organic sulfur removal from coal by rapid pyroly96104677 81s with alkali leaching and denslty separation Sugawara, K. er a/., Coal Sci. Technol., 1995, 24, (2). 1709-1712. High-temperature alkali treatment with KOH was combined with rapid pyrolysis in a free-fall reactor to successfully reduce the organic sulphur content in coal fractions separated by density differences by float-sink processes.
Roll-press brlquetting 96104685 Komarek, R. Mining Mug., Jun. 1996, 174, (6), 356, 358, 360. Discusses the compacting of mineral products into briquettes which is worrh considering for a number of reasons. Briquetting increases bulk density for easier handling, shipping or disposal; prevents caking or bridging insilos, hoppers and metering equipment; reduces dusting and segregation of fines in handling; improves remelt yields: and, in the case of fuels, improves burning characieristics. .
NO, reduction by coal brlquets 96104676 Garcia-Garcia, A. el al., Coal Sci. Technol., 1995, 24, (2), 1787-1790. Describes how fuel briquets were prepared using humic acids as a binding agent which also functioned as a carbon-based reducing agent lo reduce NO, emissions upon combustion.
96104676 drum mills Kucherenko, Describes a pulverization pulverization
334
Fuel and Energy
Abstracts
September
1996