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02667 Dewatering of HTD coal slurry by mechanical expression
01
This process may reduce the cost and the pollution problem from coal preparation plants because it is free from the waste water treatment. In addition, other dry coal cleaning systems are introduced.
Coal preparation system using magnetic separator 98102660 Chedgy, D. G. U.S. US 5,676,710 (Cl. 44-621; ClOL9/00), 14 Ott 1997, Appl.-638,663, 29 Apr 1996, IO pp. Separation of a low specific gravity clean coal fraction from a refuse fraction of high specific gravity is effected in’a coal preparation plant, which processes the fractions separately. A run of mine coal having particle sizes up to ~4 in is mixed with a slurry of water and magnetizable particles and introduced into a heavy media cyclone to separate the high and low specific gravity fractions. The high specific gravity refuse fraction is delivered to a first magnetic separator to extract the magnetizable particles, while the low specific gravity clean coal fraction is delivered to a second magnetic separator to remove the magnetizable particles. The system is highly efficient and has a high processing capacity. Desulfurization behavior in rapid pyrolysis of coals 98102661 with various pretreatments ICCS Sugawara, K. el al. DGMK Tagungsher., 1997, 9703, (Proceedings ‘97, Volume 2), 773-776. Different pre-treatments were conducted to transform the thermally stable form of organic sulfur to reactive species prior to pyrolysis. Combined process of rapid pyrolysis with KOH pre-treatment was effective for the removal of organic sulfur from sub-bituminous coal, whereas high desulfurization extents were obtained in the rapid pyrolysis with nitric acid pre-treatment for lignite. Sulfur reduction was remarkable in bituminous coal after treatment with tetralin and nitric acid. 98102662
Desulfurization of two Turkish lignites in an entrained flow reactor
Ersahan, H. et al. J. Anal. Appl. Pyrolytis, 1997, 44, (I), 65-74. Balkaya and Bolu-Mengen lignites were desulfurized by flash pyrolysis in an entrained flow reactor under a nitrogen atmosphere, in a 450-750°C temperature range. The change of sulfur types. the removal of total sulfur and volatile matter with pyrolysis temperature were found. 98102663
Desulfurizing effect of the water vapor in the process of pyrolysis of solid fuels
Minkova, V. et al. DGMK Tagungsher., 1997,9703, (Proceedings ICCS ‘97, Volume Z), 789-792. An investigation was conducted into the desulfurizing effect of steam in the process of low-temperature pyrolysis of lignite, bituminous coal, peat, and oil shale. The sulfur content decreases from 4 7% in the initial coal to 1.5% in the solid residue and 1.22% in the liquid product. Under standard conditions, the sulfur values are 3.16% and 1.42%, respectively. 98102664
Development of a selection criterion for process parameters in batch coal flotatlon
Govindarajan, B. and Rao. T. C. Trans. Sot. Min., Metal/., E&x-., 1996 (Pub. 1997). 300, 151-155. Using a simple empirical model, a simulation of batch flotation experiments was carried out to identify the process parameters that would give maximum yield at any given ash level. The 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. A simple ‘selection-criterion on the basis of this observation. The process diagram’ is proposed parameters for maximum yield for a given ash content of the concentrate and at any given flotation period can be determined with this diagram.
Development of advanced coal cleaning process 98102665 Osaka, S. et al. Sekiran Riyo Gijutsu Kaigi Koenshu, 1996, 6, 34-45, 286. (In Japanese) This study aims to develop the highly efficient and economical coal cleaning process and evaluate the effectiveness of clean coal. The development of advanced cleaning equipment, such as column flotation, micronized magnetite cyclone and super-conducting magnetic separation, the evaluation of coal cleaning properties, the fundainental process design and the cost evaluation were carried out. The detailed process design and the quantitative evaluation of clean coal use are scheduled for the total feasibility study.
98lO2667
Dewatering
Solid fuels (preparation)
of HTD coal slurry by mechanical
expression Guo, J. et al.
Coal Prep., 1997, 18, (3/4), 227-239. An attempt to develop a process for the production of a coal-water slurry fuel with a high solids concentration is presented. A novel process, elevated-temperature mechanical expression, has been proposed and the fundamentals of the process for mechanical dewatering hydrothermally dewatered (HTD) brown coal slurry have been investigated. A compression-permeability cell has been used in batch tests to study the pore destruction and dewatering characteristics of HTD coal slurry over a wide range of process-related variables. A significant improvement in the pore destruction and moisture reduction of HTD coal slurry has been realized by using elevated-temperature expression. The solids concentration of compressed pellets can be as high as 80%. The pressure required in the elevated-temperature expression is much lower than in a traditional mechanical expression. Therefore, the elevated-temperature expression has potential as an effective brown coal dewatering technique.
96102666 Dry beneficiation fluidized cascade
of coal in a countercurrent
Pechoc, J. et al. Acra Mont., Ser. AB, 1996, 2, 29-36, 125-132. (In English/ Czech) Optimum separation parameters were determined for brown coal and the process efficiency was evaluated by using the shape of the separation function.
Dry-type coal preparation method and its apparatus 98102669 Marnyama, T. er al. Jpn. Kokai Tokkyo Koho JP 09 40,980 197 40,980] (Cl. ClOL5100). 10 Feb 1997, Appl. 95/189,559,25 Jul 1995,22 pp. (In Japanese) With high-efficiency impurity removal. this dry-type coal preparation method for coal feeds having wide range particle sizes is described. It comprises drying a coal feed containing a carbonaceous fraction and an impurity fraction, pulverizing and removing magnetic material by passing the coal feed through a drying apparatus, a pulverizer and a magnetic material removal apparatus. Having 5-2.5 mm particle sizes. the coal feed is classified by a first screen and separated to a carbonaceous fraction and an impurity fraction by an ultrasound selector based on the gravity difference. The coal feed having l-2.5 mm particle sizes is classified by a second screen and separated to a carbonaceous fraction and an impurity fraction by an electromagnetic-induction selector by electromagnetic force. The coal feed fraction and an having < 1 mm particle sizes is separated to a carbonaceous impurity fraction by Coulomb force by a static selector. Drying and preheating method of coal by fluidized98102670 bed drying classifier and coke manufacture method Yokomizo, M. et al. Jpn. Kokai Tokkyo Koho JP 09.255.968 [97,255,96X] (Cl. ClOB57110). 30 Sep 1997, JP Appl. 96/6,465, 18 Jan 1996, 7 pp. (In Japanese) The paper describes a two-stage drying-pre-heating method of coal for coke-oven feed. The coal is first dried and classified into coarse and fine particles. The coarse particles are then fed to the front end of a secondstage dryer-classifier using a long horizontal fluidized-bed and the fine particles are fed separately according to the particle size distribution to a classifying chamber of the second-stage dryer-classifier along the coal discharging direction. 98lO2671
The effect of pore-modifier graphite on the performance of a zinc titanate sorbent in hot coal desulfurization
ICCS ‘97. Pineda, M. er al. DGMK Tagung.sher.. 1997, 9704, (Proceedings Volume 3), 1739-1742. The paper studies the influence of the preparation procedure on the H2S sorption capacity of zinc titanate sorbents.
98102672 Effect of water on low-temperature heat treatment of low-rank Turkish coals Artok, L. et al. DGMK Tagungsber., 1997, 9704, (Proceedings ICCS ‘97, Volume 3), 1401-1404. In the pre-treatment range of 285-330°C water promotes decarboxylation, dissociation and hydrogenation of Tunchilek sub-bituminous coal and Goynuk lignite. Decarboxylation of arylic acids in the coal mainly proceeds through proton attack on the aryl carbon attached to the carboxyl group. After the reaction in Hz/Hz0 the morphology of Tunchilek coal changed showing an agglomerated and mostly pyridine-soluble bitumen-like structure. After the reaction in Nz/HzO or dry Hz systems no agglomeration has been observed, pointing out the synergism arising from the combination of H2/H20.
Effects of lithium iodide doping on the associated molecular structure of brown coal
98102673
Dewatering of coal bed using tensides 98lO2666 Pechoc, J. Acta Mont., Ser. B, 1996, 6, 47-55. The influence of tensides on coal bed moisture dewatering in gravitational field was investigated. A hard coal bed with size 0.5 to 3 mm and three different tensides were subject to experimentation. Using of the tensides have no substantial effect on moisture in the dewatering bed but it is possible to reduce non-dewatered bed height. Using tensides for reducing residual moisture in dewatering bins with high coal bed will not be efficient. A more significant effect can be expected when dewatering on belts, where the ratio of bed height and its non-dewatered part is larger.
Kumagai, H. er al. Prepr. Pap. Am. Chem. Sot., Div. Fuel Chem., 1997, 42, (I), 258-263. The paper investigates the effects of lithium iodide doping on the associated molecular structure of brown coal. Coal devolatization is enhanced with LiI doping at lower temperature range and proceeds without thermal decomposition and cleavage of cross-linkage structure. High temperature ‘H-NMR results indicate that the LiI doping increases the fractions of mobile structure, and also enhances the mobility of molecules. LiI maintains the enhanced molecule mobility during heat treatment resulting in an increase in the evolution of volatile matter.
Fuel and Energy Abstracts
July 1998 249
This process may reduce the cost and the pollution problem from coal preparation plants because it is free from the waste water treatment. In addition, other dry coal cleaning systems are introduced.
Coal preparation system using magnetic separator 98102660 Chedgy, D. G. U.S. US 5,676,710 (Cl. 44-621; ClOL9/00), 14 Ott 1997, Appl.-638,663, 29 Apr 1996, IO pp. Separation of a low specific gravity clean coal fraction from a refuse fraction of high specific gravity is effected in’a coal preparation plant, which processes the fractions separately. A run of mine coal having particle sizes up to ~4 in is mixed with a slurry of water and magnetizable particles and introduced into a heavy media cyclone to separate the high and low specific gravity fractions. The high specific gravity refuse fraction is delivered to a first magnetic separator to extract the magnetizable particles, while the low specific gravity clean coal fraction is delivered to a second magnetic separator to remove the magnetizable particles. The system is highly efficient and has a high processing capacity. Desulfurization behavior in rapid pyrolysis of coals 98102661 with various pretreatments ICCS Sugawara, K. el al. DGMK Tagungsher., 1997, 9703, (Proceedings ‘97, Volume 2), 773-776. Different pre-treatments were conducted to transform the thermally stable form of organic sulfur to reactive species prior to pyrolysis. Combined process of rapid pyrolysis with KOH pre-treatment was effective for the removal of organic sulfur from sub-bituminous coal, whereas high desulfurization extents were obtained in the rapid pyrolysis with nitric acid pre-treatment for lignite. Sulfur reduction was remarkable in bituminous coal after treatment with tetralin and nitric acid. 98102662
Desulfurization of two Turkish lignites in an entrained flow reactor
Ersahan, H. et al. J. Anal. Appl. Pyrolytis, 1997, 44, (I), 65-74. Balkaya and Bolu-Mengen lignites were desulfurized by flash pyrolysis in an entrained flow reactor under a nitrogen atmosphere, in a 450-750°C temperature range. The change of sulfur types. the removal of total sulfur and volatile matter with pyrolysis temperature were found. 98102663
Desulfurizing effect of the water vapor in the process of pyrolysis of solid fuels
Minkova, V. et al. DGMK Tagungsher., 1997,9703, (Proceedings ICCS ‘97, Volume Z), 789-792. An investigation was conducted into the desulfurizing effect of steam in the process of low-temperature pyrolysis of lignite, bituminous coal, peat, and oil shale. The sulfur content decreases from 4 7% in the initial coal to 1.5% in the solid residue and 1.22% in the liquid product. Under standard conditions, the sulfur values are 3.16% and 1.42%, respectively. 98102664
Development of a selection criterion for process parameters in batch coal flotatlon
Govindarajan, B. and Rao. T. C. Trans. Sot. Min., Metal/., E&x-., 1996 (Pub. 1997). 300, 151-155. Using a simple empirical model, a simulation of batch flotation experiments was carried out to identify the process parameters that would give maximum yield at any given ash level. The 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. A simple ‘selection-criterion on the basis of this observation. The process diagram’ is proposed parameters for maximum yield for a given ash content of the concentrate and at any given flotation period can be determined with this diagram.
Development of advanced coal cleaning process 98102665 Osaka, S. et al. Sekiran Riyo Gijutsu Kaigi Koenshu, 1996, 6, 34-45, 286. (In Japanese) This study aims to develop the highly efficient and economical coal cleaning process and evaluate the effectiveness of clean coal. The development of advanced cleaning equipment, such as column flotation, micronized magnetite cyclone and super-conducting magnetic separation, the evaluation of coal cleaning properties, the fundainental process design and the cost evaluation were carried out. The detailed process design and the quantitative evaluation of clean coal use are scheduled for the total feasibility study.
98lO2667
Dewatering
Solid fuels (preparation)
of HTD coal slurry by mechanical
expression Guo, J. et al.
Coal Prep., 1997, 18, (3/4), 227-239. An attempt to develop a process for the production of a coal-water slurry fuel with a high solids concentration is presented. A novel process, elevated-temperature mechanical expression, has been proposed and the fundamentals of the process for mechanical dewatering hydrothermally dewatered (HTD) brown coal slurry have been investigated. A compression-permeability cell has been used in batch tests to study the pore destruction and dewatering characteristics of HTD coal slurry over a wide range of process-related variables. A significant improvement in the pore destruction and moisture reduction of HTD coal slurry has been realized by using elevated-temperature expression. The solids concentration of compressed pellets can be as high as 80%. The pressure required in the elevated-temperature expression is much lower than in a traditional mechanical expression. Therefore, the elevated-temperature expression has potential as an effective brown coal dewatering technique.
96102666 Dry beneficiation fluidized cascade
of coal in a countercurrent
Pechoc, J. et al. Acra Mont., Ser. AB, 1996, 2, 29-36, 125-132. (In English/ Czech) Optimum separation parameters were determined for brown coal and the process efficiency was evaluated by using the shape of the separation function.
Dry-type coal preparation method and its apparatus 98102669 Marnyama, T. er al. Jpn. Kokai Tokkyo Koho JP 09 40,980 197 40,980] (Cl. ClOL5100). 10 Feb 1997, Appl. 95/189,559,25 Jul 1995,22 pp. (In Japanese) With high-efficiency impurity removal. this dry-type coal preparation method for coal feeds having wide range particle sizes is described. It comprises drying a coal feed containing a carbonaceous fraction and an impurity fraction, pulverizing and removing magnetic material by passing the coal feed through a drying apparatus, a pulverizer and a magnetic material removal apparatus. Having 5-2.5 mm particle sizes. the coal feed is classified by a first screen and separated to a carbonaceous fraction and an impurity fraction by an ultrasound selector based on the gravity difference. The coal feed having l-2.5 mm particle sizes is classified by a second screen and separated to a carbonaceous fraction and an impurity fraction by an electromagnetic-induction selector by electromagnetic force. The coal feed fraction and an having < 1 mm particle sizes is separated to a carbonaceous impurity fraction by Coulomb force by a static selector. Drying and preheating method of coal by fluidized98102670 bed drying classifier and coke manufacture method Yokomizo, M. et al. Jpn. Kokai Tokkyo Koho JP 09.255.968 [97,255,96X] (Cl. ClOB57110). 30 Sep 1997, JP Appl. 96/6,465, 18 Jan 1996, 7 pp. (In Japanese) The paper describes a two-stage drying-pre-heating method of coal for coke-oven feed. The coal is first dried and classified into coarse and fine particles. The coarse particles are then fed to the front end of a secondstage dryer-classifier using a long horizontal fluidized-bed and the fine particles are fed separately according to the particle size distribution to a classifying chamber of the second-stage dryer-classifier along the coal discharging direction. 98lO2671
The effect of pore-modifier graphite on the performance of a zinc titanate sorbent in hot coal desulfurization
ICCS ‘97. Pineda, M. er al. DGMK Tagung.sher.. 1997, 9704, (Proceedings Volume 3), 1739-1742. The paper studies the influence of the preparation procedure on the H2S sorption capacity of zinc titanate sorbents.
98102672 Effect of water on low-temperature heat treatment of low-rank Turkish coals Artok, L. et al. DGMK Tagungsber., 1997, 9704, (Proceedings ICCS ‘97, Volume 3), 1401-1404. In the pre-treatment range of 285-330°C water promotes decarboxylation, dissociation and hydrogenation of Tunchilek sub-bituminous coal and Goynuk lignite. Decarboxylation of arylic acids in the coal mainly proceeds through proton attack on the aryl carbon attached to the carboxyl group. After the reaction in Hz/Hz0 the morphology of Tunchilek coal changed showing an agglomerated and mostly pyridine-soluble bitumen-like structure. After the reaction in Nz/HzO or dry Hz systems no agglomeration has been observed, pointing out the synergism arising from the combination of H2/H20.
Effects of lithium iodide doping on the associated molecular structure of brown coal
98102673
Dewatering of coal bed using tensides 98lO2666 Pechoc, J. Acta Mont., Ser. B, 1996, 6, 47-55. The influence of tensides on coal bed moisture dewatering in gravitational field was investigated. A hard coal bed with size 0.5 to 3 mm and three different tensides were subject to experimentation. Using of the tensides have no substantial effect on moisture in the dewatering bed but it is possible to reduce non-dewatered bed height. Using tensides for reducing residual moisture in dewatering bins with high coal bed will not be efficient. A more significant effect can be expected when dewatering on belts, where the ratio of bed height and its non-dewatered part is larger.
Kumagai, H. er al. Prepr. Pap. Am. Chem. Sot., Div. Fuel Chem., 1997, 42, (I), 258-263. The paper investigates the effects of lithium iodide doping on the associated molecular structure of brown coal. Coal devolatization is enhanced with LiI doping at lower temperature range and proceeds without thermal decomposition and cleavage of cross-linkage structure. High temperature ‘H-NMR results indicate that the LiI doping increases the fractions of mobile structure, and also enhances the mobility of molecules. LiI maintains the enhanced molecule mobility during heat treatment resulting in an increase in the evolution of volatile matter.
Fuel and Energy Abstracts
July 1998 249