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01848 An evaluation of fine coal flotation at the Challi Coal Washery
01
Solid fuels (preparation)
98101841 A corn arative study of batch and continuous column flotation of Pme coal (semi batch, gas hold-up) Leffler, M. P. 1997, 210 pp. Avail. UMI, Order Diss. Abstr. In?., B, 1998, 58, (7), 3900.
Desulfurization 98lOl842 column flotation
of Pittsburgh
No. DA9802682.
From
coal by microbial
Ohmura, N. and Saiki, H. Appl. Biochemical Biotechnol., 1996 (Pub. 1997), 61, (3), 339-349. Using Thiobacillus ferro-oxidans, microbial column flotation was applied for desulfurization of Pittsburgh coal-water mixture size between 38 pm and 75 pm. The coal contained ferrous ion which would interfere with the separation of pyrite from coal by microbial flotation. Therefore, the ferrous ion was washed out with OSN HCI solution. The coal was divided into two parts; the small-size coal between 38 pm and 53 pm, and the large-size coal between 53 pm and 75 pm. The pyritic sulfur content was decreased from 2.88% of the feed coal to 0.98% of the oroduct coal for the large-size coal and from 2.77% of the feed coal to 1.12% of the product coal fo; the smallsize coal by microbial flotation. The decrease was based on removal of liberated pyrite particles, but the fine particles could not be removed even though the pyrite particles were liberated from coal particles. The microbial column flotation was more effective for desulfurization of the large liberated pyrite particle than that of the small. Both the pyrite liberation from coal and its particle size are important factors for the pyrite removal by microbial column flotation.
Development of a selection criterion for process 98101843 Darameters in batch coal flotation r--~-m ~~~~ ~~~
Govindarajan, B. and Rao, T. C. Trans. Sot. Min., MetaN., Explor., 1996 (Pub. 1997), 300, 151-155. k simple impirical model was used to carry out a simulation of batch flotation exoeriments to identifv the orocess oarameters that would eive maximum $eld at any given &h lebel. Thd relationship between -the maximum yield values and the percentage ash-reduction ratio (ARR) has shown two regions where the- collector and the frother dosages have individual influences on the flotation performance. Based on this observation, a simple selection-criterion diagram is proposed. Using this diagram, the process parameters can be selected to achieve maximum yield for a given ash content of the concentration at any given flotation period.
98lO1844
Dewatering of fine coal
lvatt, S. and Shah, C. Comm. Eur. Communiries, [Rep.] EUR, 1997, (EUR 17156), 138 pp. The coal industry is subject to strict demands to improve and maintain a high and consistent quality of fuel. This has meant that fine high ash material can no longer be included as part of the final washed coal product. Imorovements and chances in undereround mining techniaues have added to the problem of fines,Owith 15-20% of mineral ‘;f size l&s than 0.5 mm reaching the coal preparation plant. The aim of this project was to examine possible ways in which the product handling ability of power station fuel could be improved by changing the nature of the fine portion of the blend. Three indeoendent research oroiects were undertaken in order to studv aspects of koisture and slimes re
Dissolved mineral species precipitation during coal
flotation
Somasundaran, P. and Liu, D. Proc. Int. Miner. Process. Congr., 19th, 1995, 3, 67-71. A promising method of coal cleaning is beneficiation by froth flotation, which exploits the difference in surface properties of minerals. However, dissolved mineral species present in coal flotation systems can interact with particles and other species leading to drastic effects on flotation. In particular, precipitation or adsorption of such species on the particles can alter their surface properties and thus influence the efficiency of coal cleaning. In this work, the bulk and surface precipitation of the dissolved mineral species present in Pittsburgh No. 8 coal was investigated under controlled experimental conditions. Changes in the surface properties of coal due to the precipitation were monitored by following zeta potential. Solution potential data were used to elucidate the mechanism of the precipitation. There was a marked effect of the precipitation of the dissolved species on the flotability of coal.
98101848 Effect of iron enrichment with GIC or FeC13 on the pore structure and reactivity of coking coal
Alibiniak, A. et al. Fuel, 1997, 76, (14/15), 1383-1387. Studies the effect of a lewis acid addition to a coking coal on the oorositv and reactivity towards steam of the resulting iron en&hed coal ch&. GId (FeClj graphite intercalation compound) or free FeCl3 are used as ironcontai&g-additives. Coal iron enrichment was performed using either directly FeClJ in vapour phase or by mixing of coal and additives in Decaline or by common grinding of coal and additives under argon. Iron enriched coals were carbonized at 750°C. The nore structures of coal chars before and after activation were evaluated an-the basis of CO2 and CsHh sorption at 25°C. A significant development of the microporosity is
170
Fuel and Energy Abstracts
May 1998
observed in the iron enriched char before activation and its steam reactivity is also increased. After activation, BET surface area values are increased in presence of iron, and porosity is mainly microporous.
98iOl847 The effect of radiation to enhance the bioconversion of coal Gazso, L. G. Fuel Process. Technol., 1997, 52, (l-3), 239-245. The water solubility of low rank coals can be enhanced by water solubility. Oxidizing species from the radiolysis of water are also important agents in coal decomposition. Radiation treatment of aqueous slurry of lignite and sub-bituminous coal in the dose range of 25-100 kGy increases the absorotion of the aaueous ohase in the interval of 250-420 nm. showine a maxi&m at 260 &. The increased solubility of coal can be aitributed”to the oxidation of organic material and the reduction in the boiling point. A multi-step physical, chemical and biological treatment is need co-convert coal into low molecular weight fuels. Radiation as a physical pre-treatment offers an alternative application for coal degradation.
98lOl848 An evaluation of fine coal flotation at the Chaili Coal Washery Zhang, R. Z. et al. Proc. Int. Miner. Process. Congr., 19th, 1995, 3, 155-159. The paper investigates the potential application of flotation for treating and processing of a fine-particle coal stream for the Chaili Coal Washery of the Zaozhuang Coal Mine Administration, Shandong Province, China. An evaluation of the application of the Microcel flotation column and a comparison of its performance to conventional flotation were included in the objectives of the tests. Small-scale flotation tests were performed in the laboratory and on-site with fine coal slurry samples from the plant thickener underflow. On-site flotation tests were conducted with a 7.6 cm diameter Microcel column and conventional small-scale cells. To determine a recovery-grade relationship for the fine coal feed and to obtain sufficient data to enable scale-up to a large-diameter unit, column flotation tests were performed. One primary objective was to establish the maximum throughput capacity of a Microcel flotation column, while operating to produce a clean coal product with ash content of 7.5-7.8%. Test results indicate that this product quality could be achieved at feed rates of 15-19 tph to a 3 m diameter Microcel flotation column. Lower ash products, i.e. 5-7% ash, were obtained but at lower column through-put capacities. Comparative flotation tests, conducted with conventional flotation cells, indicated that a product ash of only 8% or greater was achieved in a singlestage test. 98lO1849
Evaluation of response of brown coal to selective oil agglomeration by zeta potential measurements of the agglomerates
Gurses, A. et al. Fuel, 1997, 76, (14/1.5), 1439-1444. The recovery of agglomerate and the reduction of ash and pyritic sulfur were observed to determine how they were affected by suspension pH, the concentration of surfactant and the concentrations of electrolytes in selective oil agglomeration. The results revealed a correlation between recovery and reductions in ash and pyritic sulfur and the zeta potential of the agglomerates.
98iO1850 Experiment studies on dehydration of fine particle coal by cationic quaternary ammonium salt graft copolymer Xia, C. et al. Xiangtan Kuangye Xueyunn Xuebao, 1997, 12, (3), 71-76. (In Chinese) The paper describes experimental studies on the dehydration of fine particle coal using cationic quaternary ammonium salt graft copolymer as a flocculant. The effects of flocculant quantity, molecular weight and vacuum on the dehydration abilities are discussed in detail. The technical targets of dehydrating fine particle coal can be significantly improved with this flocculant, as shown by the results.
98lO1851 Experimental studies on steam pressure filtration of coal concentrate filter cakes Gerl, S. and Stahl, W. Proc. Int. Miner. Process. Congr., 19fh, 1995, 2, 107111. Mechanical and thermal processes are combined in one filtration device using steam pressure filtration. Steam condensation at the cold layers of the filter cake build a condensation front, which even removes the capillary water from the porous filter cake. Depending on the choice of parameters it is possible to achieve a very low residual moisture content. Bench scale apparatus was implemented to research the influence of the parameters on the dewatering results. The physical fundamentals, the influence of the cake dewatering parameters and one possible method of applying the process to a disk filter device are discussed.
98lO1852 Expert system for control of coal beneficiatlon plants (as illustrated by coal flotation) Ul’shin, V. A. and Zubov, Russian)
D. A.
Koks Khim.,
1997, (8), 36-40.
(In
Solid fuels (preparation)
98101841 A corn arative study of batch and continuous column flotation of Pme coal (semi batch, gas hold-up) Leffler, M. P. 1997, 210 pp. Avail. UMI, Order Diss. Abstr. In?., B, 1998, 58, (7), 3900.
Desulfurization 98lOl842 column flotation
of Pittsburgh
No. DA9802682.
From
coal by microbial
Ohmura, N. and Saiki, H. Appl. Biochemical Biotechnol., 1996 (Pub. 1997), 61, (3), 339-349. Using Thiobacillus ferro-oxidans, microbial column flotation was applied for desulfurization of Pittsburgh coal-water mixture size between 38 pm and 75 pm. The coal contained ferrous ion which would interfere with the separation of pyrite from coal by microbial flotation. Therefore, the ferrous ion was washed out with OSN HCI solution. The coal was divided into two parts; the small-size coal between 38 pm and 53 pm, and the large-size coal between 53 pm and 75 pm. The pyritic sulfur content was decreased from 2.88% of the feed coal to 0.98% of the oroduct coal for the large-size coal and from 2.77% of the feed coal to 1.12% of the product coal fo; the smallsize coal by microbial flotation. The decrease was based on removal of liberated pyrite particles, but the fine particles could not be removed even though the pyrite particles were liberated from coal particles. The microbial column flotation was more effective for desulfurization of the large liberated pyrite particle than that of the small. Both the pyrite liberation from coal and its particle size are important factors for the pyrite removal by microbial column flotation.
Development of a selection criterion for process 98101843 Darameters in batch coal flotation r--~-m ~~~~ ~~~
Govindarajan, B. and Rao, T. C. Trans. Sot. Min., MetaN., Explor., 1996 (Pub. 1997), 300, 151-155. k simple impirical model was used to carry out a simulation of batch flotation exoeriments to identifv the orocess oarameters that would eive maximum $eld at any given &h lebel. Thd relationship between -the maximum yield values and the percentage ash-reduction ratio (ARR) has shown two regions where the- collector and the frother dosages have individual influences on the flotation performance. Based on this observation, a simple selection-criterion diagram is proposed. Using this diagram, the process parameters can be selected to achieve maximum yield for a given ash content of the concentration at any given flotation period.
98lO1844
Dewatering of fine coal
lvatt, S. and Shah, C. Comm. Eur. Communiries, [Rep.] EUR, 1997, (EUR 17156), 138 pp. The coal industry is subject to strict demands to improve and maintain a high and consistent quality of fuel. This has meant that fine high ash material can no longer be included as part of the final washed coal product. Imorovements and chances in undereround mining techniaues have added to the problem of fines,Owith 15-20% of mineral ‘;f size l&s than 0.5 mm reaching the coal preparation plant. The aim of this project was to examine possible ways in which the product handling ability of power station fuel could be improved by changing the nature of the fine portion of the blend. Three indeoendent research oroiects were undertaken in order to studv aspects of koisture and slimes re
Dissolved mineral species precipitation during coal
flotation
Somasundaran, P. and Liu, D. Proc. Int. Miner. Process. Congr., 19th, 1995, 3, 67-71. A promising method of coal cleaning is beneficiation by froth flotation, which exploits the difference in surface properties of minerals. However, dissolved mineral species present in coal flotation systems can interact with particles and other species leading to drastic effects on flotation. In particular, precipitation or adsorption of such species on the particles can alter their surface properties and thus influence the efficiency of coal cleaning. In this work, the bulk and surface precipitation of the dissolved mineral species present in Pittsburgh No. 8 coal was investigated under controlled experimental conditions. Changes in the surface properties of coal due to the precipitation were monitored by following zeta potential. Solution potential data were used to elucidate the mechanism of the precipitation. There was a marked effect of the precipitation of the dissolved species on the flotability of coal.
98101848 Effect of iron enrichment with GIC or FeC13 on the pore structure and reactivity of coking coal
Alibiniak, A. et al. Fuel, 1997, 76, (14/15), 1383-1387. Studies the effect of a lewis acid addition to a coking coal on the oorositv and reactivity towards steam of the resulting iron en&hed coal ch&. GId (FeClj graphite intercalation compound) or free FeCl3 are used as ironcontai&g-additives. Coal iron enrichment was performed using either directly FeClJ in vapour phase or by mixing of coal and additives in Decaline or by common grinding of coal and additives under argon. Iron enriched coals were carbonized at 750°C. The nore structures of coal chars before and after activation were evaluated an-the basis of CO2 and CsHh sorption at 25°C. A significant development of the microporosity is
170
Fuel and Energy Abstracts
May 1998
observed in the iron enriched char before activation and its steam reactivity is also increased. After activation, BET surface area values are increased in presence of iron, and porosity is mainly microporous.
98iOl847 The effect of radiation to enhance the bioconversion of coal Gazso, L. G. Fuel Process. Technol., 1997, 52, (l-3), 239-245. The water solubility of low rank coals can be enhanced by water solubility. Oxidizing species from the radiolysis of water are also important agents in coal decomposition. Radiation treatment of aqueous slurry of lignite and sub-bituminous coal in the dose range of 25-100 kGy increases the absorotion of the aaueous ohase in the interval of 250-420 nm. showine a maxi&m at 260 &. The increased solubility of coal can be aitributed”to the oxidation of organic material and the reduction in the boiling point. A multi-step physical, chemical and biological treatment is need co-convert coal into low molecular weight fuels. Radiation as a physical pre-treatment offers an alternative application for coal degradation.
98lOl848 An evaluation of fine coal flotation at the Chaili Coal Washery Zhang, R. Z. et al. Proc. Int. Miner. Process. Congr., 19th, 1995, 3, 155-159. The paper investigates the potential application of flotation for treating and processing of a fine-particle coal stream for the Chaili Coal Washery of the Zaozhuang Coal Mine Administration, Shandong Province, China. An evaluation of the application of the Microcel flotation column and a comparison of its performance to conventional flotation were included in the objectives of the tests. Small-scale flotation tests were performed in the laboratory and on-site with fine coal slurry samples from the plant thickener underflow. On-site flotation tests were conducted with a 7.6 cm diameter Microcel column and conventional small-scale cells. To determine a recovery-grade relationship for the fine coal feed and to obtain sufficient data to enable scale-up to a large-diameter unit, column flotation tests were performed. One primary objective was to establish the maximum throughput capacity of a Microcel flotation column, while operating to produce a clean coal product with ash content of 7.5-7.8%. Test results indicate that this product quality could be achieved at feed rates of 15-19 tph to a 3 m diameter Microcel flotation column. Lower ash products, i.e. 5-7% ash, were obtained but at lower column through-put capacities. Comparative flotation tests, conducted with conventional flotation cells, indicated that a product ash of only 8% or greater was achieved in a singlestage test. 98lO1849
Evaluation of response of brown coal to selective oil agglomeration by zeta potential measurements of the agglomerates
Gurses, A. et al. Fuel, 1997, 76, (14/1.5), 1439-1444. The recovery of agglomerate and the reduction of ash and pyritic sulfur were observed to determine how they were affected by suspension pH, the concentration of surfactant and the concentrations of electrolytes in selective oil agglomeration. The results revealed a correlation between recovery and reductions in ash and pyritic sulfur and the zeta potential of the agglomerates.
98iO1850 Experiment studies on dehydration of fine particle coal by cationic quaternary ammonium salt graft copolymer Xia, C. et al. Xiangtan Kuangye Xueyunn Xuebao, 1997, 12, (3), 71-76. (In Chinese) The paper describes experimental studies on the dehydration of fine particle coal using cationic quaternary ammonium salt graft copolymer as a flocculant. The effects of flocculant quantity, molecular weight and vacuum on the dehydration abilities are discussed in detail. The technical targets of dehydrating fine particle coal can be significantly improved with this flocculant, as shown by the results.
98lO1851 Experimental studies on steam pressure filtration of coal concentrate filter cakes Gerl, S. and Stahl, W. Proc. Int. Miner. Process. Congr., 19fh, 1995, 2, 107111. Mechanical and thermal processes are combined in one filtration device using steam pressure filtration. Steam condensation at the cold layers of the filter cake build a condensation front, which even removes the capillary water from the porous filter cake. Depending on the choice of parameters it is possible to achieve a very low residual moisture content. Bench scale apparatus was implemented to research the influence of the parameters on the dewatering results. The physical fundamentals, the influence of the cake dewatering parameters and one possible method of applying the process to a disk filter device are discussed.
98lO1852 Expert system for control of coal beneficiatlon plants (as illustrated by coal flotation) Ul’shin, V. A. and Zubov, Russian)
D. A.
Koks Khim.,
1997, (8), 36-40.
(In