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02680 Investigation of laws of selective flocculation of coals with synthetic latexes
01
So/id fuels (preparation)
Estimation of water-coal surface interaction in 98102874 brown coal during heat treatment by utilization of FTIR and DSC Miura, K. er al. DGMK Tagungsber., 1997, 9702, (Proceedings ICCS ‘97, Volume l), 191-194. In order to estimate the strength of coal-water interaction in a brown coal and the enthalpy change from the change in hydrogen bondings during the desorption of wafer, FTIR and DSC measurements were applied. The estimated enthalpy change was compared with the total enthalpy change estimated by DSC measurements to examine the importance of hydrogen bonding during the desorption of water. The enthalpy was found to decrease with the progress of desorption. The study clarified the importance of the rearrangement of hydrogen bondings and the entropy effect.
9aio26al process
Flokob flotation column with double aeration of a
Brzezina, R. and Sablik, J. frregl. Corn., 1996, 52, (12), 22-30. (In Polish) Presents semi-commercial research results on the influence of the basic parameters of the coal slurries flotation process on the performance of the column machine Flokob. A decisive parameter for the machine performance is the way of slurry aeration and the amount of air dispergated in it. Conditions enabling process control and obtaining cleaning results of predicated quality are given. Premises for the operation parameter determination and the way of controlling of coal slurry cleaning products quality in the commercial machines have been worked out, based on the obtained results. 98102676
Froth flotation of coal fines using alkaline diesel-oil waste as the collector
Zhulin, N. V. Russ. RU 2,077,957 (Cl. B03D1/02), 27 Apr 1997, Appl. 94,037,350, 28 Sep 1994. From fzohreteniya 1997, (12), 65. (In Russian)
Heat treatment of high-volatile coals at the pre98102677 plasticity stage Aioshtein. S. A. DGMK Ta~un,&er., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 829-832. _ i The paper studies the effects of low-temperature structurization processes, at the stage of preplasticity of high-volatile coals, on their caking and swelling abilities. The results of the evaluation of the swelling indexes of the coal samples are tabulated for temperature treatment at 200 and 250°C. With the increase of the temperature of heat treatment from 200-250°C the yield of CO? and that of saturated hydrocarbons (Cz-C4) decreases regularly, while the yield of CO rises. The increases in the yield of CO, Hz, and CzHh takes place at 400-500°C.
Influence of heterogeneous catalysts on the co98102678 processing of Bergneda lignite with a vacuum residue al. Rev. Inst. Fr. Pet., 1997, 52, (l), 61-71. (In French) Benrros. C. el For-the catalytic co-processing of a Catalan lignite with vacuum residue under an atmosphere of hydrogen, seven different heterogeneous catalysts were tested. Four of these were iron-based catalysts supported on yalumina with increasing loading of iron oxide. The fifth was a bimodal catalyst of iron and molybdenum and the last two were commercial hydrotreatment catalysts. Tests were also conducted with y-alumina and without catalyst. The catalytic performance of these catalysts is modified by the high level of mineral matter present in this lignite. The highest values of coal conversion are obtained without catalyst and with the catalysts containing the highest loading of iron.
oil agglomeration
Zhang, F. and Wheelock, T. D. Coal Prep., 1997, 18, (l/2), 69-90. The kinetics of a gas-promoted process for agglomerating an aqueous suspension of coal particles, using either heptane or hexadecane as an agglomerant, was examined by a turbidimetric method. Suspensions of either Pittsburgh No. 8 seam coal or Upper Freeport seam coal were mixed with measured quantities of air and an agglomerant in a closed cylindrical tank fitted with baffles and a controllable speed agitator. Agglomeration was monitored by observing the change in turbidity of the suspension. The experimental data were correlated and analysed by employing a semiempirical rate equation which gave consistent results.
96iO2682 9aiO2675 slurry
Kinetics of a gas-promoted
Kinetics of filter cakes dewatering
Pechoc, J. Acta Mont., Ser. B, 1996, 6, 57-67. Dewatering of the bed of fine coals as a result of pressure difference and with air through suction is considered. The laboratory experiments conditions were similar to those used with dewatering by vacuum filtration on the drum rotary filters. On the basis of rate of liquid flow through the bed, which can be described by Darcy’s law, the dewatering rate was generalized. Thus it is possible to compare kinetics of dewatering with various hydrodynamic conditions. The effect of tenside addition to the dewatering kinetics was also investigated.
98102683 Low temperature extractability and solvent swelling of Turkish lignites Onal, Y. and Ceylan, K. Fuel Process. Technol., 1997, 53, (l/2), 81-97. Solutions of HCI or sodium ethanolate have been used for the pretreatment of six Turkish lignites at room temperature or lSO”C. The volumetric swelling of the raw or pre-treated lignites have been investigated by using 13 solvents at room temperature These lignites have been subjected to Soxhlet extractions in the same solvents and in the linear alkylamines. The solubility of the samples in toluene under supercritical conditions were also tested. The effect of solvent on swelling ratio and on the extraction yields of the raw or pre-treated lignites have been examined. The results have indicated that both swelling and extraction. yields generally increased after the pre-treatments and the increments are higher with hydrogen bonding solvents. The results suggest that solvent solubility parameter and electron donor number ate effective in both swelling and solubility. 98102684
Macerallmicrolithotype electrostatic dry coal cleaning
partitioning through tribo-
Hower, J. C. et al. Int. J. Coal Geol., 1997, 34, (3-4). 277-285. Testing of three eastern Kentucky and two Illinois Basin coals took place in a bench-scale triboelectrostatic separation unit. The three eastern Kentucky samples provided a rank series of petrographical comparable coals. The Illinois Basin bituminous coals were lower rank and had high vitrinite and sulfur contents in comparison. Trihoelectrostatic heneficiation provides efficient maceral and mineral partitioning in the high volatile A and B bituminous coals tested, with vitrinite, as vitrite and vitrinite-enriched microlithotypes, reporting to the clean fractions and the inertinites, liptinites, and minerals reporting to the tails. The high volatile carbon bituminous Springfield coal had a lower separation efficiency than the petrographical similar, but higher rank, Herrin coal. The decreased separation efficiency in the behaviour of the Springfield coal may he a response to its higher moisture content. Compared to bench-scale fuel oil agglomeration of some of the same coals, triboelectrostatic separation provides clearer partitioning of mineral matter, sulfur, and macerals.
Method for preparing charge coal by heating to be used in coke oven
96102665
The influence of surface phenomena on the de98102679 watering of fine clean coal Singh, B. P. F&r. Sep., 1997, 34, (2). 159-163. Experimental results from work carried out to study the role of surface active agents in the dewatering of fine clean coal. The work examined the fundamental phenomena which determine their mode of action and the mechanism of surfactant-enhanced dewatering is investigated in terms of the surface chemistry phenomena and the physical processes involved in the dewatering. The performance and possible mode of action are compared between two surfactant dewatering aids. The results of dewatering experiments show that the presence of the sodium dodecyl sulfate leads to a very significant reduction in the final residual cake moisture content. Between the point of zero charge, surface tension reduction in the coal system and residual moisture reduction in the filter cake, a direct and strong correlation exists. These improvements are attributed to the changes in the wetting characteristics of the coal particles in the presence of effective dewatering aids. 98102680
Investigation of laws of selective flocculation of coals with synthetic latexes
Sergeev, P. V. and Biletskyi, V. S. DGMK Tugungsber., 1997, 9702, (Proceedings ICCS ‘97, Volume 1). 503-506. For possible application as selective flocculants in Ukrainian coal industry, synthetic latexes were investigated and tested. A model of the process of polymer flocculation is briefly introduced and the theoretical and practical aspects of latex flocculants application are described.
250
Fuel and Energy Abstracts
July 1996
Komaki, I. Jpn. Kokai Tokkyo Koho JP 09 13.042 [97 13,042) (Cl. ClOBS7/10), 14 Jan 1997, Appl. 951163,374, 29 Jun 1995, 4 pp. (In Japanese) Blended coking coal and non-coking coal are heated at 250-350°C then screened to obtain fine powders having ~0.3 mm particle size. The fine powders are heated at 350-450°C and moulded. followed by mixing with coarse powders having ~0.3 mm particle size, to he charged into coke oven.
96iO2666 coal
Microbial flotation desulfurization
technology of
Zhang, T. et al. Shanghai Huanjing Kexue, 1997, 16, (3) 17-19. (In Chinese) Microbial flotation is reviewed as a novel desulfurization technology for pyritic sulfur removal from a coal slurry prior to combustion. Some specific micro-organisms adhere selectively to pyrite particles. The floatability was suppressed by the adhesion of bacteria on pyrite particles by changing the surface properties from hydrophobic to hydrophilic to promote the pyritic sulfur form in coal during flotation. This technology requires a shorter contact time than conventional microbial desulfurization and has a high removal efficiency of pyritic sulfur without producing a large amount of acidic wastewater. It is possible to recover the pyrite removed from this process and the coal quality is improved.
96lO2687 Pozhidaev, Russian)
Modelling of coal flotation V. F. and Rubinshtein,
Y. B.
Woks Khim., 1997, (6) 10-13. (In
So/id fuels (preparation)
Estimation of water-coal surface interaction in 98102874 brown coal during heat treatment by utilization of FTIR and DSC Miura, K. er al. DGMK Tagungsber., 1997, 9702, (Proceedings ICCS ‘97, Volume l), 191-194. In order to estimate the strength of coal-water interaction in a brown coal and the enthalpy change from the change in hydrogen bondings during the desorption of wafer, FTIR and DSC measurements were applied. The estimated enthalpy change was compared with the total enthalpy change estimated by DSC measurements to examine the importance of hydrogen bonding during the desorption of water. The enthalpy was found to decrease with the progress of desorption. The study clarified the importance of the rearrangement of hydrogen bondings and the entropy effect.
9aio26al process
Flokob flotation column with double aeration of a
Brzezina, R. and Sablik, J. frregl. Corn., 1996, 52, (12), 22-30. (In Polish) Presents semi-commercial research results on the influence of the basic parameters of the coal slurries flotation process on the performance of the column machine Flokob. A decisive parameter for the machine performance is the way of slurry aeration and the amount of air dispergated in it. Conditions enabling process control and obtaining cleaning results of predicated quality are given. Premises for the operation parameter determination and the way of controlling of coal slurry cleaning products quality in the commercial machines have been worked out, based on the obtained results. 98102676
Froth flotation of coal fines using alkaline diesel-oil waste as the collector
Zhulin, N. V. Russ. RU 2,077,957 (Cl. B03D1/02), 27 Apr 1997, Appl. 94,037,350, 28 Sep 1994. From fzohreteniya 1997, (12), 65. (In Russian)
Heat treatment of high-volatile coals at the pre98102677 plasticity stage Aioshtein. S. A. DGMK Ta~un,&er., 1997, 9703, (Proceedings ICCS ‘97, Volume 2) 829-832. _ i The paper studies the effects of low-temperature structurization processes, at the stage of preplasticity of high-volatile coals, on their caking and swelling abilities. The results of the evaluation of the swelling indexes of the coal samples are tabulated for temperature treatment at 200 and 250°C. With the increase of the temperature of heat treatment from 200-250°C the yield of CO? and that of saturated hydrocarbons (Cz-C4) decreases regularly, while the yield of CO rises. The increases in the yield of CO, Hz, and CzHh takes place at 400-500°C.
Influence of heterogeneous catalysts on the co98102678 processing of Bergneda lignite with a vacuum residue al. Rev. Inst. Fr. Pet., 1997, 52, (l), 61-71. (In French) Benrros. C. el For-the catalytic co-processing of a Catalan lignite with vacuum residue under an atmosphere of hydrogen, seven different heterogeneous catalysts were tested. Four of these were iron-based catalysts supported on yalumina with increasing loading of iron oxide. The fifth was a bimodal catalyst of iron and molybdenum and the last two were commercial hydrotreatment catalysts. Tests were also conducted with y-alumina and without catalyst. The catalytic performance of these catalysts is modified by the high level of mineral matter present in this lignite. The highest values of coal conversion are obtained without catalyst and with the catalysts containing the highest loading of iron.
oil agglomeration
Zhang, F. and Wheelock, T. D. Coal Prep., 1997, 18, (l/2), 69-90. The kinetics of a gas-promoted process for agglomerating an aqueous suspension of coal particles, using either heptane or hexadecane as an agglomerant, was examined by a turbidimetric method. Suspensions of either Pittsburgh No. 8 seam coal or Upper Freeport seam coal were mixed with measured quantities of air and an agglomerant in a closed cylindrical tank fitted with baffles and a controllable speed agitator. Agglomeration was monitored by observing the change in turbidity of the suspension. The experimental data were correlated and analysed by employing a semiempirical rate equation which gave consistent results.
96iO2682 9aiO2675 slurry
Kinetics of a gas-promoted
Kinetics of filter cakes dewatering
Pechoc, J. Acta Mont., Ser. B, 1996, 6, 57-67. Dewatering of the bed of fine coals as a result of pressure difference and with air through suction is considered. The laboratory experiments conditions were similar to those used with dewatering by vacuum filtration on the drum rotary filters. On the basis of rate of liquid flow through the bed, which can be described by Darcy’s law, the dewatering rate was generalized. Thus it is possible to compare kinetics of dewatering with various hydrodynamic conditions. The effect of tenside addition to the dewatering kinetics was also investigated.
98102683 Low temperature extractability and solvent swelling of Turkish lignites Onal, Y. and Ceylan, K. Fuel Process. Technol., 1997, 53, (l/2), 81-97. Solutions of HCI or sodium ethanolate have been used for the pretreatment of six Turkish lignites at room temperature or lSO”C. The volumetric swelling of the raw or pre-treated lignites have been investigated by using 13 solvents at room temperature These lignites have been subjected to Soxhlet extractions in the same solvents and in the linear alkylamines. The solubility of the samples in toluene under supercritical conditions were also tested. The effect of solvent on swelling ratio and on the extraction yields of the raw or pre-treated lignites have been examined. The results have indicated that both swelling and extraction. yields generally increased after the pre-treatments and the increments are higher with hydrogen bonding solvents. The results suggest that solvent solubility parameter and electron donor number ate effective in both swelling and solubility. 98102684
Macerallmicrolithotype electrostatic dry coal cleaning
partitioning through tribo-
Hower, J. C. et al. Int. J. Coal Geol., 1997, 34, (3-4). 277-285. Testing of three eastern Kentucky and two Illinois Basin coals took place in a bench-scale triboelectrostatic separation unit. The three eastern Kentucky samples provided a rank series of petrographical comparable coals. The Illinois Basin bituminous coals were lower rank and had high vitrinite and sulfur contents in comparison. Trihoelectrostatic heneficiation provides efficient maceral and mineral partitioning in the high volatile A and B bituminous coals tested, with vitrinite, as vitrite and vitrinite-enriched microlithotypes, reporting to the clean fractions and the inertinites, liptinites, and minerals reporting to the tails. The high volatile carbon bituminous Springfield coal had a lower separation efficiency than the petrographical similar, but higher rank, Herrin coal. The decreased separation efficiency in the behaviour of the Springfield coal may he a response to its higher moisture content. Compared to bench-scale fuel oil agglomeration of some of the same coals, triboelectrostatic separation provides clearer partitioning of mineral matter, sulfur, and macerals.
Method for preparing charge coal by heating to be used in coke oven
96102665
The influence of surface phenomena on the de98102679 watering of fine clean coal Singh, B. P. F&r. Sep., 1997, 34, (2). 159-163. Experimental results from work carried out to study the role of surface active agents in the dewatering of fine clean coal. The work examined the fundamental phenomena which determine their mode of action and the mechanism of surfactant-enhanced dewatering is investigated in terms of the surface chemistry phenomena and the physical processes involved in the dewatering. The performance and possible mode of action are compared between two surfactant dewatering aids. The results of dewatering experiments show that the presence of the sodium dodecyl sulfate leads to a very significant reduction in the final residual cake moisture content. Between the point of zero charge, surface tension reduction in the coal system and residual moisture reduction in the filter cake, a direct and strong correlation exists. These improvements are attributed to the changes in the wetting characteristics of the coal particles in the presence of effective dewatering aids. 98102680
Investigation of laws of selective flocculation of coals with synthetic latexes
Sergeev, P. V. and Biletskyi, V. S. DGMK Tugungsber., 1997, 9702, (Proceedings ICCS ‘97, Volume 1). 503-506. For possible application as selective flocculants in Ukrainian coal industry, synthetic latexes were investigated and tested. A model of the process of polymer flocculation is briefly introduced and the theoretical and practical aspects of latex flocculants application are described.
250
Fuel and Energy Abstracts
July 1996
Komaki, I. Jpn. Kokai Tokkyo Koho JP 09 13.042 [97 13,042) (Cl. ClOBS7/10), 14 Jan 1997, Appl. 951163,374, 29 Jun 1995, 4 pp. (In Japanese) Blended coking coal and non-coking coal are heated at 250-350°C then screened to obtain fine powders having ~0.3 mm particle size. The fine powders are heated at 350-450°C and moulded. followed by mixing with coarse powders having ~0.3 mm particle size, to he charged into coke oven.
96iO2666 coal
Microbial flotation desulfurization
technology of
Zhang, T. et al. Shanghai Huanjing Kexue, 1997, 16, (3) 17-19. (In Chinese) Microbial flotation is reviewed as a novel desulfurization technology for pyritic sulfur removal from a coal slurry prior to combustion. Some specific micro-organisms adhere selectively to pyrite particles. The floatability was suppressed by the adhesion of bacteria on pyrite particles by changing the surface properties from hydrophobic to hydrophilic to promote the pyritic sulfur form in coal during flotation. This technology requires a shorter contact time than conventional microbial desulfurization and has a high removal efficiency of pyritic sulfur without producing a large amount of acidic wastewater. It is possible to recover the pyrite removed from this process and the coal quality is improved.
96lO2687 Pozhidaev, Russian)
Modelling of coal flotation V. F. and Rubinshtein,
Y. B.
Woks Khim., 1997, (6) 10-13. (In