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Combustion and fragmentation characteristics of Korean anthracite
0 1 Solid fuels (sources, winning, properties)
01
SOLID FUELS Sources,
winning,
properties
02/01760 A statistical evaluation on the correlations between thermal fragmentation of South African coal and coal characteristics van Dyk, J. C. and Falcon, R. Proceedings - Annual Internationrrl Pittsburgh
Cocrl Conference,
2000, (17), 514-522.
A study was conducted to postulate a fragmentation mechanism by exploring the different causes of primary fragmentation and to examine correlations between the degree of fragmentation and standard coal analyses. Coal characteristics studied indicated that a combination of moisture, volatiles, maceral and mineral matter play a role in the thermal fragmentation of coal. Percentage moisture, on an air dry basis, in coal is the most important characteristics significantly affecting thermal fragmentation. A correlation coefficient of 0.72 exists in the correlation of moisture and thermal fragmentation, which implies that 72% of the fragmentation can be explained by moisture. Although moisture is the only characteristic that contributes significantly towards fragmentation, it is clear that a complex interaction of other factors also contribute towards fragmentation. 02/01761 Assessment of sulphur content of coal from Saoner coal mines Kamavisdar, A. and Sirociya, R. S. Indian J. Environ. Health, 2000, 42, (3), 138-141.
Coal samples from the Saoner coal mines situated near Nagpur city, MS, India were analysed for the detection and speciation of sulphur. The pyretic, sulphate and organic form percentages of sulphur were detected. Most of the coal samples were found to contain high percentage of pyretic sulphur. The approximate emission of sulphur in the environment of the study area is modelled on year basis. The results indicated that environmental problems, i.e. acid rain may be noticed in the study area in near future, if some precautionary steps are not taken to reduce the sulphur content of these coal prior to its utilization. 02/01762 Coal resources of Orissa vis-a-vis the growth of Mahanadi Coalfields Limited Ray, M. K. K. and Mishra, G. K. Journcrl q/Mines, Metalsand Fuels, 2000, 48, (1 l&12), 300-337. Of the six Gondwaria basins in the state of Orissa, two (Talcher and IbValley coalfields) contain promising coal reserves. Systematic exploratory efforts have revealed the potential of these two coalfields which contain nearly 23% of the national coal reserves and thus being accorded the most favourable coalfield status as far as quarriable potentiality is concerned. To tap this vast coal resources of Orissa, a separate subsidiary, i.e. Mahanadi Coalfields Limited was formed in 1992. At the time of nationalization of coal industrv in 1973, coal production from all the mines of Orissa was only 1.6 million tones per year and since then with high growth in production and despatch, these coalfields have recorded a total production of 43.5 million tones during 1998-99 and occupied second position among the coal producing subsidiaries of Coal India Ltd. Out of 37 billion tonnes of total estimated geological reserves up to 300 m depth, 23 billion tonnes are confined to the area identified for detailed exploration at present. Out of this, around 11 billion tonnes of coal reserves have been categorized as ‘proved reserves’, suitable for mine planning. From the balance 12 billion tonnes, 5 billion tonnes are under exploration and 7 billion tonnes are yet to be explored in detail. Based on the long term linkage granted by standing committee, a total demand of 122.6 million tonnes per year have been projected during 2006-7 and accordingly coal production has been planned and the total projected coal production capacity to be created by that time is estimated to be 135 million tonnes per year. Keeping this scenario in view, an attempt has been made in this paper to evaluate the coal resource position of Orissa and assess the prospects of Mahanadi Coalfields Ltd to meet the growing demand of coal in future. 02101763 Combustion and fragmentation characteristics of Korean anthracite Lee, J. et al. Proceedings of rhe lnternutionrrl Cotzference on Nuidked Bed Comhrrstion, 2001, (l6), 1513-1521. The combustion kinetics of Korean anthracite was determined in a TGA reactor. The combustion rate was much slower than that of bituminous coal and could be expressed by shrinking core model in which the activation energy and the frequency factor in chemical reaction control regime were 51.2 kcalimol and 1.492x 10” s ‘, respectively. Information on the fragmentation of the anthracite was 232
Fuel and Energy Abstracts
July 2002
obtained with variation of the heating rate, the particle size and the reaction temperature for seven different Korean anthracites in a TGA and a thermobalance reactor. The fragmentation increased with an increase of the heating rate and the reaction temperature. Depending on the particle size and the species of the coal, the fragmentation occurred with a different degree of the fragmentation. The fragmentation ratio (Nou&N,.) increased as the volatile and carbon contents in coal increased. Consequently, the fragmentation of the anthracite occurred tremendously and a number of find particles were newly generated. 02101764 Comprehensive combustion control in the face in Baodian coal mine, Wen, H. et al. Proc. - Annu.
technique for spontaneous no.1306 fully mechanized caving China Int. Pittsburgh
Coal Cor$,
2000, (17),
2113-2117.
Control of spontaneous combustion in coal mines without coal blocks was studied for the Yanzhou coal fields. Emphasis was on adjacent gob, float coal on the top of roadways, face heading, and spot line, especially float coal along adjacent gob of fully mechanized caving face (FMCF in short). For the sake of decreasing the cost of fire control, separation belts for fire prevention are set up by gel and powdery inert retarding agent. Spray-cement and balanced pressure are used for control of spontaneous combustion of float coal in the No.1306 FMCF. The gel technique for fire control combines characteristics of leak-blocking, cooling, oxidation-retarding, heat resistance and water-fixation. For the sake of improving the work environment in mines, a new agglomerating agent without amine and corrosion has been developed to replace acid and amine salt used in the past. The gel-injection technology together with the grouting system solves problems of gel-injection velocity and material transport. Its cost is high for fire prevention. The powdery inert retarding agent is made of many kinds of materials; it can be successively decomposed to release inert gas and drop the temperature of coal by heat absorption. Its cost is low for fire prevention. Correlation for estimating volatile matter of coals 02/01765 Singh, K. P. and Kakati, M. C. C/lem. Eng. Commun., 2001, (187), 6575. A set of 460 Indian coal samples has been used to establish correlations between volatile matter percentage yield (%VMdmmf) and compositional parameters, such as the weight% of Carbon (Cw), Hydrogen (Hw) and Oxygen (0~); atmospheric ratios of the H/C, O/C and H/C; and atmospheric percentages of Carbon (Ca), Hydrogen (Ha) and Oxygen (Oa). Based on dry, mineral-matter-free (dmmf) basis wt% volatile matter is estimated by a set of equations. The standard error of estimate and correlation coefficients of the developed correlations are given. 02/01766 Dielectric properties of coal Marland, S. et al. Fue/, 2001, 80, (l3), 1839-1849. Dielectric measurements of UK coals have shown that electric permittivity decreases with coal rank (dry, mineral free basis), however, the moisture and mineral matter content may increase the bulk coal electric permittivity. Electric permittivity increases with low rank coals as a result of increasing moisture levels associated with low rank coals. The relative real permittivity of coal is greater than most composite mineral matter with exception of pyrite, which may increase the bulk coal electric permittivity if present in sufficient quantity, No significant changes in electric permittivity were detected in the frequency range tested. Effect of the sulfur content on the weathering of 02lO1767 coal: comparison of two coal beds in Hato de la Virgen (carbonera formation), Venezuela Martinez, M. et ul. Estudios Geologicox iMudridj, 2000. 56. (3-4). l4l152. (In Spanish) Ten bituminous coal samples, showing several weathering levels, were collected at different depths into two subsurface galleries: G-11, where coalbed 20 is mining, with a sulphur-content > 5%; and G-24, where coalbed 24 is present, with a sulphur content less than 1.5%). Both mines are located in Hato de la Virgen, State of Tachira, Venezuela, The aim of this work is to evaluate the effect of sulphur on the weathering extent in coal. For comparative purposes, fresh samples were collected from cored intervals of four different wells near of the galleries. The following analyses were done: proximate (moisture, volatile matter, fixed carbon, ash, calorific power), free swelling index (FSI) elemental analysis (C, H, N, 0) total and different sulphur species (pyritic, sulphate and organic sulphur), FT-IR IR spectroscopy, and major component of ash (Si, Al, Ca, Mg, Mn, Fe, K, Na. Cl, P). Only coal samples from core wells are absolutely fresh: those collected within galleries show evidence of low or remarkable oxidation, detected by several parameters (moisture, calorific power, elemental and ash components) and by IR spectroscopy (appearance of carbonyl signal, decrease in C-H strength absorption). Sulphur content in a high proportion does not modify the style or extension of the oxidation in
01
SOLID FUELS Sources,
winning,
properties
02/01760 A statistical evaluation on the correlations between thermal fragmentation of South African coal and coal characteristics van Dyk, J. C. and Falcon, R. Proceedings - Annual Internationrrl Pittsburgh
Cocrl Conference,
2000, (17), 514-522.
A study was conducted to postulate a fragmentation mechanism by exploring the different causes of primary fragmentation and to examine correlations between the degree of fragmentation and standard coal analyses. Coal characteristics studied indicated that a combination of moisture, volatiles, maceral and mineral matter play a role in the thermal fragmentation of coal. Percentage moisture, on an air dry basis, in coal is the most important characteristics significantly affecting thermal fragmentation. A correlation coefficient of 0.72 exists in the correlation of moisture and thermal fragmentation, which implies that 72% of the fragmentation can be explained by moisture. Although moisture is the only characteristic that contributes significantly towards fragmentation, it is clear that a complex interaction of other factors also contribute towards fragmentation. 02/01761 Assessment of sulphur content of coal from Saoner coal mines Kamavisdar, A. and Sirociya, R. S. Indian J. Environ. Health, 2000, 42, (3), 138-141.
Coal samples from the Saoner coal mines situated near Nagpur city, MS, India were analysed for the detection and speciation of sulphur. The pyretic, sulphate and organic form percentages of sulphur were detected. Most of the coal samples were found to contain high percentage of pyretic sulphur. The approximate emission of sulphur in the environment of the study area is modelled on year basis. The results indicated that environmental problems, i.e. acid rain may be noticed in the study area in near future, if some precautionary steps are not taken to reduce the sulphur content of these coal prior to its utilization. 02/01762 Coal resources of Orissa vis-a-vis the growth of Mahanadi Coalfields Limited Ray, M. K. K. and Mishra, G. K. Journcrl q/Mines, Metalsand Fuels, 2000, 48, (1 l&12), 300-337. Of the six Gondwaria basins in the state of Orissa, two (Talcher and IbValley coalfields) contain promising coal reserves. Systematic exploratory efforts have revealed the potential of these two coalfields which contain nearly 23% of the national coal reserves and thus being accorded the most favourable coalfield status as far as quarriable potentiality is concerned. To tap this vast coal resources of Orissa, a separate subsidiary, i.e. Mahanadi Coalfields Limited was formed in 1992. At the time of nationalization of coal industrv in 1973, coal production from all the mines of Orissa was only 1.6 million tones per year and since then with high growth in production and despatch, these coalfields have recorded a total production of 43.5 million tones during 1998-99 and occupied second position among the coal producing subsidiaries of Coal India Ltd. Out of 37 billion tonnes of total estimated geological reserves up to 300 m depth, 23 billion tonnes are confined to the area identified for detailed exploration at present. Out of this, around 11 billion tonnes of coal reserves have been categorized as ‘proved reserves’, suitable for mine planning. From the balance 12 billion tonnes, 5 billion tonnes are under exploration and 7 billion tonnes are yet to be explored in detail. Based on the long term linkage granted by standing committee, a total demand of 122.6 million tonnes per year have been projected during 2006-7 and accordingly coal production has been planned and the total projected coal production capacity to be created by that time is estimated to be 135 million tonnes per year. Keeping this scenario in view, an attempt has been made in this paper to evaluate the coal resource position of Orissa and assess the prospects of Mahanadi Coalfields Ltd to meet the growing demand of coal in future. 02101763 Combustion and fragmentation characteristics of Korean anthracite Lee, J. et al. Proceedings of rhe lnternutionrrl Cotzference on Nuidked Bed Comhrrstion, 2001, (l6), 1513-1521. The combustion kinetics of Korean anthracite was determined in a TGA reactor. The combustion rate was much slower than that of bituminous coal and could be expressed by shrinking core model in which the activation energy and the frequency factor in chemical reaction control regime were 51.2 kcalimol and 1.492x 10” s ‘, respectively. Information on the fragmentation of the anthracite was 232
Fuel and Energy Abstracts
July 2002
obtained with variation of the heating rate, the particle size and the reaction temperature for seven different Korean anthracites in a TGA and a thermobalance reactor. The fragmentation increased with an increase of the heating rate and the reaction temperature. Depending on the particle size and the species of the coal, the fragmentation occurred with a different degree of the fragmentation. The fragmentation ratio (Nou&N,.) increased as the volatile and carbon contents in coal increased. Consequently, the fragmentation of the anthracite occurred tremendously and a number of find particles were newly generated. 02101764 Comprehensive combustion control in the face in Baodian coal mine, Wen, H. et al. Proc. - Annu.
technique for spontaneous no.1306 fully mechanized caving China Int. Pittsburgh
Coal Cor$,
2000, (17),
2113-2117.
Control of spontaneous combustion in coal mines without coal blocks was studied for the Yanzhou coal fields. Emphasis was on adjacent gob, float coal on the top of roadways, face heading, and spot line, especially float coal along adjacent gob of fully mechanized caving face (FMCF in short). For the sake of decreasing the cost of fire control, separation belts for fire prevention are set up by gel and powdery inert retarding agent. Spray-cement and balanced pressure are used for control of spontaneous combustion of float coal in the No.1306 FMCF. The gel technique for fire control combines characteristics of leak-blocking, cooling, oxidation-retarding, heat resistance and water-fixation. For the sake of improving the work environment in mines, a new agglomerating agent without amine and corrosion has been developed to replace acid and amine salt used in the past. The gel-injection technology together with the grouting system solves problems of gel-injection velocity and material transport. Its cost is high for fire prevention. The powdery inert retarding agent is made of many kinds of materials; it can be successively decomposed to release inert gas and drop the temperature of coal by heat absorption. Its cost is low for fire prevention. Correlation for estimating volatile matter of coals 02/01765 Singh, K. P. and Kakati, M. C. C/lem. Eng. Commun., 2001, (187), 6575. A set of 460 Indian coal samples has been used to establish correlations between volatile matter percentage yield (%VMdmmf) and compositional parameters, such as the weight% of Carbon (Cw), Hydrogen (Hw) and Oxygen (0~); atmospheric ratios of the H/C, O/C and H/C; and atmospheric percentages of Carbon (Ca), Hydrogen (Ha) and Oxygen (Oa). Based on dry, mineral-matter-free (dmmf) basis wt% volatile matter is estimated by a set of equations. The standard error of estimate and correlation coefficients of the developed correlations are given. 02/01766 Dielectric properties of coal Marland, S. et al. Fue/, 2001, 80, (l3), 1839-1849. Dielectric measurements of UK coals have shown that electric permittivity decreases with coal rank (dry, mineral free basis), however, the moisture and mineral matter content may increase the bulk coal electric permittivity. Electric permittivity increases with low rank coals as a result of increasing moisture levels associated with low rank coals. The relative real permittivity of coal is greater than most composite mineral matter with exception of pyrite, which may increase the bulk coal electric permittivity if present in sufficient quantity, No significant changes in electric permittivity were detected in the frequency range tested. Effect of the sulfur content on the weathering of 02lO1767 coal: comparison of two coal beds in Hato de la Virgen (carbonera formation), Venezuela Martinez, M. et ul. Estudios Geologicox iMudridj, 2000. 56. (3-4). l4l152. (In Spanish) Ten bituminous coal samples, showing several weathering levels, were collected at different depths into two subsurface galleries: G-11, where coalbed 20 is mining, with a sulphur-content > 5%; and G-24, where coalbed 24 is present, with a sulphur content less than 1.5%). Both mines are located in Hato de la Virgen, State of Tachira, Venezuela, The aim of this work is to evaluate the effect of sulphur on the weathering extent in coal. For comparative purposes, fresh samples were collected from cored intervals of four different wells near of the galleries. The following analyses were done: proximate (moisture, volatile matter, fixed carbon, ash, calorific power), free swelling index (FSI) elemental analysis (C, H, N, 0) total and different sulphur species (pyritic, sulphate and organic sulphur), FT-IR IR spectroscopy, and major component of ash (Si, Al, Ca, Mg, Mn, Fe, K, Na. Cl, P). Only coal samples from core wells are absolutely fresh: those collected within galleries show evidence of low or remarkable oxidation, detected by several parameters (moisture, calorific power, elemental and ash components) and by IR spectroscopy (appearance of carbonyl signal, decrease in C-H strength absorption). Sulphur content in a high proportion does not modify the style or extension of the oxidation in