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Column flotation for deep clean coals, and the effect of mineral compositions and size distributions
Conference and within coal seams. Siderites varied in composition from siderite, CO, to magnesian siderite Fe,,,,Mg,,,, Fe o.sJMg,.,,Ca,.,,Mn,.,z Ca,.,, CO, and to calcian siderite Fe,,,,Mg,,,,Ca,,,,Mn~,~~CO,. Ankerites varied in composition from dolomite, CaMg(CO,), to O,Os)(CO,),. Cleat infillings by calcite ankerite Ca(Mg,,,Fe,,,Ca were typically uniform in composition, whereas cleat infillings by dolomiteeankerite were often variable in composition, with zones of dolomite/ferroan dolomiteiankerite observed parallel to the cleat. Four compositional siderite types are recognized in Australian coals: siderite, magnesian siderite, calcian siderite and magnesian-calcian siderite. The amount and type of carbonate minerals are important in relation to ash fusion and slagging characteristics of Australian bituminous coals. Work is in progress on the variability ofcarbonate mineralogy within the Blackwater and the Moura to Theodore districts in Queensland. These districts contain coals with lower ash fusion temperatures and selective mining might enable production of coals well suited for IGCC processes. Implications of the compositional and regional variability of carbonate minerals will be discussed in relation to selection of coals for use in slagging gasifiers.
Kinetic and equilibrium studies on carbon molecular sieves S. R. Patwnrdhan, S. N. Vyas, S. Vijayalakshmi Indian
and K. Sriganesh
of Technology, Bombay, Department of Engineering, IIT, Powai, Bombay-400 076, India
Institute
Chemical
Coke deposition by deep cracking of hydrocarbons on wide pore mouths of char has become an interesting aspect of adsorption due to a high selectivity of product carbon molecular sieves (CMS) towards the adsorption of one or other component from its mixture with other gases. In the present work, CMS was synthesized from coconut shell by three major process steps, namely carbonization, activation and hydrocarbon (benzene) cracking. The crushed, washed and sieved granules of coconut shell of particle size 2 to 3 mm were pretreated with sodium silicate solution to create active inorganic sites necessary for coke deposition, and then oven dried at 150°C. Carbonization and activation of the dried granules were carried out at 800°C for 30min each. The activated char thus produced was subjected to benzene cracking at 600°C. The product samples were characterized in terms of adsorption isotherm, kinetic adsorption curve, surface area, pore volume. pore size distribution, characteristic energy and diffusion parameter by using O,, N,, C,H,, C,H, and CH,.
Column flotation for deep clean coals, and the effect of mineral compositions and size distributions F. F. Peng and E. H. Cho West Virginia University, Department Engineering, 309B COMER Building, WV 26506-6070, USA
Paramagnetic characteristics bituminous coal extracts
Abstracts
of reductively alkylated
A. F. Popoa, I. E. Nosyrea, V.I. Bessaraboc
and I/: P. Strigutsky*
The L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, Ukrainian Academy of Sciences, Donetsk 340114, Ukraine *The Institute for Problems of the Use of Natural Resources and Ecology, Byelorussian Academy of Sciences, Minsk 220114, Byelorus The bituminous coal (85.9% C, daf) was activated in the potassiumnaphthalene-tetrahydrofuran system or by vapours of metallic potassium. The polyanion intermediate was alkylated by ethyl iodide. The alkylated coal was successively extracted by hexane, N,N-dimethylacetamide and benzene. The separate extracts free from solvent and their pair mixtures were studied by non-linear e.p.r. spectroscopy. It has been established that the concentration ofparamagnetic centres is always lower in the pair mixtures than calculated on the additivity principles. It has been detected that the e.p.r. signal of the N,N-dimethylacetamide fraction is not practically saturated by SHF power. It has been shown that associative interactions between organic molecules are the reason for paramagnetic centres appearing in extracts from the reductively alkylated bituminous coal. The regularities that we have detected may be used for control of the directed change of the coal organic matter reactivity in pyrolysis processes.
Coal utilization and environment in China Zhang Quanguo, Zhang Bailiang and Liu Shengyong Henan Agricultural University, Energy Engineering Laboratory, Zhengzhou, HN450002, P.R. China In 1991 the output of Chinese coal was 1062.43 million tonnes, the highest output in the world. Most of the energy in China is produced by burning coal and the resultant smoke pollution is an obvious characteristic of air pollution. Therefore, the prevention and control of the air pollution from burning coal is a pressing and long-term objective in China. In this paper, the characteristics of coal utilization, the situation regarding air pollution, industrial experiences and achievements in scientific research for preventing and controlling the pollution in China are described. It is concluded that further control of air pollution in China depends to a great extent on the development of cogeneration, domestic gas, briquette burning technique with fixed-sulfur additives, advanced burning coal facilities and management, which should therefore be spurred and encouraged.
of Mineral Processing Morgantown,
Fine coal flotation can be significantly improved by using a flotation column that funtions as rougher, cleaner and scavenger in a single unit. This paper presents the experimental results of a column flotation for deep cleaning of fine coals. For this study, three US coals obtained from Upper Freeport, Pittsburgh no. 8 and Illinois no. 6 seam coal are used. The coal samples are prepared by using an attrition mill so that 90% passes -37 {trn (-400 mesh). MIBC is used as the frother and kerosene is used as collector. In this flotation column, microbubbles are generated from an atomizer and sparging system. In addition, wash water is used to clean the froth product to remove the entrained ash particles. With the appropriate combination of flotation operating parameters, column flotation has shown the capability of producing a deep clean coal product with a ver low ash/sulfur and high carbon recovery as compared to the conventional flotation and other existing multistage flotation circuits. The operating parameters of column flotation include feed rate, air flow rate, wash water flow rate, pulp concentration, froth/collector dosages, tailing flow rate and column height. In fact, column flotation has achieved the maximum separation of mineral from fine coals allowed by physical separation methods. The selectivity of column flotation varies with the degree of mineral liberation, mineral composition and mineral size distribution in the feed coal. The mineral size and composition distribution for the deep clean coal products will be evaluated and discussed.
New methods and devices for effective sampling, preparation and investigation of coal samples S. A. Radchenko Institute of the Comprehensive Mineral Exploitation of the Academy of Sciences Department of Problems of Mine Gases Kryukovskii Tupik 4, Moscow, 111020,
Resources of Russia, and Dust, Russia
One of the problems that arises during coal utilization and protection of the environment is the increased accuracy of investigations of coal properties and effective and efficient control of their variation. This problem is relevant both during the mining of gaseous deposits and the main stages of coal utilization. The analysis of methods and equipment for sampling, transportation, storing coal samples and preparing them for investigation demonstrated that many of them do not satisfy modern requirements because they do not guarantee the conservation of primary properties of the samples till the beginning of the investigation or are immensely time- and labour-consuming for reliable results being guaranteed. The creation of new methods of preparing samples for investigation, the measurement of gas emission and other characteristics, and analysing the experimental data provided the basis for the design and assembly of a new class of more effective, reliable and simple universal
Fuel 1993
Volume
72 Number
5
721
Kinetic and equilibrium studies on carbon molecular sieves S. R. Patwnrdhan, S. N. Vyas, S. Vijayalakshmi Indian
and K. Sriganesh
of Technology, Bombay, Department of Engineering, IIT, Powai, Bombay-400 076, India
Institute
Chemical
Coke deposition by deep cracking of hydrocarbons on wide pore mouths of char has become an interesting aspect of adsorption due to a high selectivity of product carbon molecular sieves (CMS) towards the adsorption of one or other component from its mixture with other gases. In the present work, CMS was synthesized from coconut shell by three major process steps, namely carbonization, activation and hydrocarbon (benzene) cracking. The crushed, washed and sieved granules of coconut shell of particle size 2 to 3 mm were pretreated with sodium silicate solution to create active inorganic sites necessary for coke deposition, and then oven dried at 150°C. Carbonization and activation of the dried granules were carried out at 800°C for 30min each. The activated char thus produced was subjected to benzene cracking at 600°C. The product samples were characterized in terms of adsorption isotherm, kinetic adsorption curve, surface area, pore volume. pore size distribution, characteristic energy and diffusion parameter by using O,, N,, C,H,, C,H, and CH,.
Column flotation for deep clean coals, and the effect of mineral compositions and size distributions F. F. Peng and E. H. Cho West Virginia University, Department Engineering, 309B COMER Building, WV 26506-6070, USA
Paramagnetic characteristics bituminous coal extracts
Abstracts
of reductively alkylated
A. F. Popoa, I. E. Nosyrea, V.I. Bessaraboc
and I/: P. Strigutsky*
The L. M. Litvinenko Institute of Physical Organic and Coal Chemistry, Ukrainian Academy of Sciences, Donetsk 340114, Ukraine *The Institute for Problems of the Use of Natural Resources and Ecology, Byelorussian Academy of Sciences, Minsk 220114, Byelorus The bituminous coal (85.9% C, daf) was activated in the potassiumnaphthalene-tetrahydrofuran system or by vapours of metallic potassium. The polyanion intermediate was alkylated by ethyl iodide. The alkylated coal was successively extracted by hexane, N,N-dimethylacetamide and benzene. The separate extracts free from solvent and their pair mixtures were studied by non-linear e.p.r. spectroscopy. It has been established that the concentration ofparamagnetic centres is always lower in the pair mixtures than calculated on the additivity principles. It has been detected that the e.p.r. signal of the N,N-dimethylacetamide fraction is not practically saturated by SHF power. It has been shown that associative interactions between organic molecules are the reason for paramagnetic centres appearing in extracts from the reductively alkylated bituminous coal. The regularities that we have detected may be used for control of the directed change of the coal organic matter reactivity in pyrolysis processes.
Coal utilization and environment in China Zhang Quanguo, Zhang Bailiang and Liu Shengyong Henan Agricultural University, Energy Engineering Laboratory, Zhengzhou, HN450002, P.R. China In 1991 the output of Chinese coal was 1062.43 million tonnes, the highest output in the world. Most of the energy in China is produced by burning coal and the resultant smoke pollution is an obvious characteristic of air pollution. Therefore, the prevention and control of the air pollution from burning coal is a pressing and long-term objective in China. In this paper, the characteristics of coal utilization, the situation regarding air pollution, industrial experiences and achievements in scientific research for preventing and controlling the pollution in China are described. It is concluded that further control of air pollution in China depends to a great extent on the development of cogeneration, domestic gas, briquette burning technique with fixed-sulfur additives, advanced burning coal facilities and management, which should therefore be spurred and encouraged.
of Mineral Processing Morgantown,
Fine coal flotation can be significantly improved by using a flotation column that funtions as rougher, cleaner and scavenger in a single unit. This paper presents the experimental results of a column flotation for deep cleaning of fine coals. For this study, three US coals obtained from Upper Freeport, Pittsburgh no. 8 and Illinois no. 6 seam coal are used. The coal samples are prepared by using an attrition mill so that 90% passes -37 {trn (-400 mesh). MIBC is used as the frother and kerosene is used as collector. In this flotation column, microbubbles are generated from an atomizer and sparging system. In addition, wash water is used to clean the froth product to remove the entrained ash particles. With the appropriate combination of flotation operating parameters, column flotation has shown the capability of producing a deep clean coal product with a ver low ash/sulfur and high carbon recovery as compared to the conventional flotation and other existing multistage flotation circuits. The operating parameters of column flotation include feed rate, air flow rate, wash water flow rate, pulp concentration, froth/collector dosages, tailing flow rate and column height. In fact, column flotation has achieved the maximum separation of mineral from fine coals allowed by physical separation methods. The selectivity of column flotation varies with the degree of mineral liberation, mineral composition and mineral size distribution in the feed coal. The mineral size and composition distribution for the deep clean coal products will be evaluated and discussed.
New methods and devices for effective sampling, preparation and investigation of coal samples S. A. Radchenko Institute of the Comprehensive Mineral Exploitation of the Academy of Sciences Department of Problems of Mine Gases Kryukovskii Tupik 4, Moscow, 111020,
Resources of Russia, and Dust, Russia
One of the problems that arises during coal utilization and protection of the environment is the increased accuracy of investigations of coal properties and effective and efficient control of their variation. This problem is relevant both during the mining of gaseous deposits and the main stages of coal utilization. The analysis of methods and equipment for sampling, transportation, storing coal samples and preparing them for investigation demonstrated that many of them do not satisfy modern requirements because they do not guarantee the conservation of primary properties of the samples till the beginning of the investigation or are immensely time- and labour-consuming for reliable results being guaranteed. The creation of new methods of preparing samples for investigation, the measurement of gas emission and other characteristics, and analysing the experimental data provided the basis for the design and assembly of a new class of more effective, reliable and simple universal
Fuel 1993
Volume
72 Number
5
721