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01275 Specifying fly ash for durable concrete
05 Nuclear fuels (scientific, technical) Phase composition of solid residues of fluidlzed bed coal combustion, quality tests, and application possibilities
96lQ1266
Brandstetr, J. and Havlica, J. Chemical Pup., 1996, 50, (4), 188-194. The newly produced ashes, the residues after fluidized bed coal combustion, are the focus of this work. The favourite phase composition of this material due to low combustion temperature of 850°C exhibits very good cementitious properties. Fluidized ashes may be preferably used in the production of some types of Portland cement as a gypsum replacement and in cement-free concretes. The quality tests of this sulfa-calcareous material are proposed as well as some application possibilities.
Preparation of activated carbons from bituminous coals with CO* activation influence of coal oxidation
wCtl267
Teng, H. et al. Carbon, 1997, 35, (2), 275-283. Activated carbons were prepared from three Australian bituminous coals and the effect of coal oxidation on the carbonization and activation processes and the structure of the resulting activated carbons was explored. During the oxidation, the amount of oxygen uptake decreased with the O/C atomic ratio of the raw coal. The carbonization of the oxidized coal exhibited a broader volatile evolution with respect to temperature, and the resulting char from the oxidized coal had a larger surface area. The oxidation of the coal precursors resulted in increases in the specific surface area and pore volume of the resulting activated carbons. The activation rate in COz was higher and the structure more accessible for COz penetration in the carbons from the oxidized coals.
Preparation of active carbons from coal. Part II. Carbonization of oxidized coal
98/01266
Pis, J. J. et al. Fuel Process. Technol., 1997, 50, (2/3), 249-260. Differing in origin, volatile matter (VM) content, plastic properties and degree of pre-oxidation, four coals were carbonized in nitrogen up to 1123 K. VM and oxygen contents of the chars obtained from unoxidized coals were very low. An increase in the degree/of coal pre-oxidation was generally accompanied by an increase in the VM content of the chars. However, the oxygen content increases only at lower degrees of preoxidation While the mercury density of the chars decreases, the helium density increases with the degree of coal pre-oxidation and is related almost linearly to the helium densities of the oxidized coals. Pre-oxidation of coal also influences the pore size distribution of chars. The pore size distribution, increasingly favours micropores as the degree of coal preoxidation is enhanced. The percentage of micropores increases from 30% to more than 70% after coal pre-oxidation. Unoxidized coal chars adsorb an insignificant amount of nitrogen at 77 K while an appreciable amount of COz is adsorbed at 273 K. The large difference between Nz and COz adsorption on chars prepared from coals with low oxidation degree becomes smaller as the degree of coal pre-oxidation increases. There is a linear relationship between the total pore volume of the char and that of the corresponding oxidized coal, indicating that the chars produced by carbonization of oxidized coal retain fingerprints of the pore structure of the precursor oxidized coal.
Preparation of mesocarbon mlcrobeads by dispersing mesophase pitch in isotropic pitches
98/01269
Korai, S. et al. Carbon, 1997, 35, (lO-ll), 1503-1515. The synthetic mesophase pitches are dispersed in synthetic isotropic pitches and successive solvent extraction is used to prepare mesocarbon microbeads of l-10 pm. The suitable ratio of mesophase pitch/isotropic pitch, temperature and rapid agitation at dispersion were found to be key factors in obtaining high yields of tetrahydrofuran and pyridine insoluble microbeads which were 34 and 20 wt% of the highest yield, respectively. The combinations of coal tar derived mesophase pitch/synthetic pitch or synthetic mesophase pitch/petroleum A240 pitch failed to disperse spheres of mesophase pitch in the isotropic matrix, leaving bulk grains of mesophase pitch at the bottom of the matrix. Agitation disperses the melt mesophase pitch of adequate viscosity into viscous droplets in the isotropic matrix, while the droplets stay afloat because of their similar specific gravities. The lighter component in the droplet of the mesophase pitch was extracted into the isotropic matrix while the mesophase pitch is melted, leaving spheres of smooth surface. Extraction by the solvent at a lower temperature than the softening point removes the solvent soluble fraction, leaving mesocarbon microbeads isolated.
96lO1272 Production of bricks from coal production waste (experience of the Occidental Industry firm) 74-76. (In Russian) Svintsitskii. R et al. f&o/ C//V., 1996, (lO-ll), Brick production from coal industry to that of the Ukraine.
wastes in the climate
situation
similar
Properties of cement-fly ash grout admixed with bentonite, silica fume, or organic fiber
9BlOl273
Huang, W.-H. Gem. Concr. Rex, 1997, 27, (3) 395-406. In order to investigate the properties of cement-fly ash grout mixtures as barriers for isolation of hazardous and low-level radioactive wastes, a detailed laboratory study was conducted. In the grout studied, fly ash was used to replace 30% by mass of cement. Three additives including bentonite, silica fume, and polypropylene fibre were used individually in the grout mixes to improve the properties of the grouts in different aspects. The flowability, bleeding, and setting time of freshly mixed grouts were determined and the unconfined compressive strength, pore size distribution, and water permeability were determined for hardened grouts at various curing durations up to 120 days. Finally, the durability of cement-fly ash grouts was carefully examined in terms of the changes in their physical properties after different levels of exposure to sulfate attack and wet-dry cycles.
96101274 Pyrite-containing wastes from beneficiation Moscow Basin coals as hydrogenation catalysts
of
Krichko, A. A. et al. Khim. Tverd. Topl., 1997, (l), 39-43. (In Russian) Coal pyrite is used in the catalytic hydrogenation of brown coal from the Berezovo deposit.
Specifying fly ash for durable concrete 96101275 Keck, R. H. and Riggs, E. H. Concr. Int., 1997, 19, (4) 35-38. Some of the advantages of fly ash utilization, regarding the durability hardened concrete. 9BlOl276 Synthetic erionitezeolite T Krais, S. Pet. Coal, 1996, 38, (1). 57-64. The author describes the preparation and characteristics possible uses are also discussed.
of erionite
Utilization of a scrap tyre-waste carbonous residue as an asphalt modifier
96101277
of
T. Its
oil derived
Rethfuss, C. and Cha, C.-Y. Polym. Recycl., 1996, 2, (3) 201-212. An advanced process for co-retorting waste oils with scrap tires to produce an upgraded oil, a fuel gas, and a carbonous residue has been developed by the University of Wyoming Chemical and Petroleum Engineering Department. The University of Wyoming has investigated the special properties of the carbonous residue in an attempt to maximize performance in asphalt modification, provide a potential source of industrial grade I carbon black, and examine the possibility of using the residue as a hydroponic salt or mineral rich fertilizer. Recent emphasis has been placed on the testing of various carbonous residue modified asphalts to determine weather resistance, viscosity effects and strength enhancements. Positive trends in all three of these areas have been observed. Through this continued research the process has proved economically sound and environmentally beneficial and could provide a mechanism for the safe and efficient management of two significant global resource problems in years to come.
96lO1276
Utilization of coal ash as fine aggregates
Hisaka, M. and Mano, T. Konkurito Kogaku, 1996, 34, (7), 102-103. (In Japanese) The level of ash generation, ash quality, and quality of concrete products using coal ash as fine aggregate are discussed.
Vapor pressures and heats of vaporization primary coal tars (tar evaporation)
96101279
Oia. V. 1997. 319 CID.Avail. UMI, Order A&. Int., B, i998, %, (7), 3785.
05
NUCLEAR
No. DA9738602.
of
From Diss.
FUELS
Process control for producing carbon products from coke-pitch mixtures
9BlOl270
Avramenko, P. Y. and Vlasov, E. E. Russ. RU 2,085,485 (Cl. COlB31/04), 27 Jul 1997, SU Appl. 5,061,400, 3 Sep 1992. From Izobreteniyu 1997, (21), 265. (In Russian)
Production of active carbon from Agacli lignite 9BlOl271 Aksu, F. et al. Chim. Acta Turc., 1997, 25, (2), 67-72. (In German) Active carbon is produced using agacli coal (lignite), by chemical activation at higher temperatures (400-1000°C) with saturated ZnClz and Cat& solutions. An optimum temperature interval of 500-600°C was obtained. Adsorption of methylene blue from the solution occurred according to the BET equation and the surface area of the active carbon was -350 m’/g.
112
Fuel and Energy Abstracts
March 1996
Scientific,
Technical
96lO1260 Applicability of carbonationldecarbonation tlons for storing thermal energy from nuclear reactors
reac-
Kyaw, K. et al. JAERI-Conf: 1996, 96-010, 408-420. So far, heat energy extracted from nuclear reactors has only been used for power generation. Recently, cleaner fuels such as hydrogen and methanol are being considered as strong possibilities for resolving global warming and oil shortage problems. From the view point of best energy mixing or highly developed energy system, it is important to study the possibility of making
96lQ1266
Brandstetr, J. and Havlica, J. Chemical Pup., 1996, 50, (4), 188-194. The newly produced ashes, the residues after fluidized bed coal combustion, are the focus of this work. The favourite phase composition of this material due to low combustion temperature of 850°C exhibits very good cementitious properties. Fluidized ashes may be preferably used in the production of some types of Portland cement as a gypsum replacement and in cement-free concretes. The quality tests of this sulfa-calcareous material are proposed as well as some application possibilities.
Preparation of activated carbons from bituminous coals with CO* activation influence of coal oxidation
wCtl267
Teng, H. et al. Carbon, 1997, 35, (2), 275-283. Activated carbons were prepared from three Australian bituminous coals and the effect of coal oxidation on the carbonization and activation processes and the structure of the resulting activated carbons was explored. During the oxidation, the amount of oxygen uptake decreased with the O/C atomic ratio of the raw coal. The carbonization of the oxidized coal exhibited a broader volatile evolution with respect to temperature, and the resulting char from the oxidized coal had a larger surface area. The oxidation of the coal precursors resulted in increases in the specific surface area and pore volume of the resulting activated carbons. The activation rate in COz was higher and the structure more accessible for COz penetration in the carbons from the oxidized coals.
Preparation of active carbons from coal. Part II. Carbonization of oxidized coal
98/01266
Pis, J. J. et al. Fuel Process. Technol., 1997, 50, (2/3), 249-260. Differing in origin, volatile matter (VM) content, plastic properties and degree of pre-oxidation, four coals were carbonized in nitrogen up to 1123 K. VM and oxygen contents of the chars obtained from unoxidized coals were very low. An increase in the degree/of coal pre-oxidation was generally accompanied by an increase in the VM content of the chars. However, the oxygen content increases only at lower degrees of preoxidation While the mercury density of the chars decreases, the helium density increases with the degree of coal pre-oxidation and is related almost linearly to the helium densities of the oxidized coals. Pre-oxidation of coal also influences the pore size distribution of chars. The pore size distribution, increasingly favours micropores as the degree of coal preoxidation is enhanced. The percentage of micropores increases from 30% to more than 70% after coal pre-oxidation. Unoxidized coal chars adsorb an insignificant amount of nitrogen at 77 K while an appreciable amount of COz is adsorbed at 273 K. The large difference between Nz and COz adsorption on chars prepared from coals with low oxidation degree becomes smaller as the degree of coal pre-oxidation increases. There is a linear relationship between the total pore volume of the char and that of the corresponding oxidized coal, indicating that the chars produced by carbonization of oxidized coal retain fingerprints of the pore structure of the precursor oxidized coal.
Preparation of mesocarbon mlcrobeads by dispersing mesophase pitch in isotropic pitches
98/01269
Korai, S. et al. Carbon, 1997, 35, (lO-ll), 1503-1515. The synthetic mesophase pitches are dispersed in synthetic isotropic pitches and successive solvent extraction is used to prepare mesocarbon microbeads of l-10 pm. The suitable ratio of mesophase pitch/isotropic pitch, temperature and rapid agitation at dispersion were found to be key factors in obtaining high yields of tetrahydrofuran and pyridine insoluble microbeads which were 34 and 20 wt% of the highest yield, respectively. The combinations of coal tar derived mesophase pitch/synthetic pitch or synthetic mesophase pitch/petroleum A240 pitch failed to disperse spheres of mesophase pitch in the isotropic matrix, leaving bulk grains of mesophase pitch at the bottom of the matrix. Agitation disperses the melt mesophase pitch of adequate viscosity into viscous droplets in the isotropic matrix, while the droplets stay afloat because of their similar specific gravities. The lighter component in the droplet of the mesophase pitch was extracted into the isotropic matrix while the mesophase pitch is melted, leaving spheres of smooth surface. Extraction by the solvent at a lower temperature than the softening point removes the solvent soluble fraction, leaving mesocarbon microbeads isolated.
96lO1272 Production of bricks from coal production waste (experience of the Occidental Industry firm) 74-76. (In Russian) Svintsitskii. R et al. f&o/ C//V., 1996, (lO-ll), Brick production from coal industry to that of the Ukraine.
wastes in the climate
situation
similar
Properties of cement-fly ash grout admixed with bentonite, silica fume, or organic fiber
9BlOl273
Huang, W.-H. Gem. Concr. Rex, 1997, 27, (3) 395-406. In order to investigate the properties of cement-fly ash grout mixtures as barriers for isolation of hazardous and low-level radioactive wastes, a detailed laboratory study was conducted. In the grout studied, fly ash was used to replace 30% by mass of cement. Three additives including bentonite, silica fume, and polypropylene fibre were used individually in the grout mixes to improve the properties of the grouts in different aspects. The flowability, bleeding, and setting time of freshly mixed grouts were determined and the unconfined compressive strength, pore size distribution, and water permeability were determined for hardened grouts at various curing durations up to 120 days. Finally, the durability of cement-fly ash grouts was carefully examined in terms of the changes in their physical properties after different levels of exposure to sulfate attack and wet-dry cycles.
96101274 Pyrite-containing wastes from beneficiation Moscow Basin coals as hydrogenation catalysts
of
Krichko, A. A. et al. Khim. Tverd. Topl., 1997, (l), 39-43. (In Russian) Coal pyrite is used in the catalytic hydrogenation of brown coal from the Berezovo deposit.
Specifying fly ash for durable concrete 96101275 Keck, R. H. and Riggs, E. H. Concr. Int., 1997, 19, (4) 35-38. Some of the advantages of fly ash utilization, regarding the durability hardened concrete. 9BlOl276 Synthetic erionitezeolite T Krais, S. Pet. Coal, 1996, 38, (1). 57-64. The author describes the preparation and characteristics possible uses are also discussed.
of erionite
Utilization of a scrap tyre-waste carbonous residue as an asphalt modifier
96101277
of
T. Its
oil derived
Rethfuss, C. and Cha, C.-Y. Polym. Recycl., 1996, 2, (3) 201-212. An advanced process for co-retorting waste oils with scrap tires to produce an upgraded oil, a fuel gas, and a carbonous residue has been developed by the University of Wyoming Chemical and Petroleum Engineering Department. The University of Wyoming has investigated the special properties of the carbonous residue in an attempt to maximize performance in asphalt modification, provide a potential source of industrial grade I carbon black, and examine the possibility of using the residue as a hydroponic salt or mineral rich fertilizer. Recent emphasis has been placed on the testing of various carbonous residue modified asphalts to determine weather resistance, viscosity effects and strength enhancements. Positive trends in all three of these areas have been observed. Through this continued research the process has proved economically sound and environmentally beneficial and could provide a mechanism for the safe and efficient management of two significant global resource problems in years to come.
96lO1276
Utilization of coal ash as fine aggregates
Hisaka, M. and Mano, T. Konkurito Kogaku, 1996, 34, (7), 102-103. (In Japanese) The level of ash generation, ash quality, and quality of concrete products using coal ash as fine aggregate are discussed.
Vapor pressures and heats of vaporization primary coal tars (tar evaporation)
96101279
Oia. V. 1997. 319 CID.Avail. UMI, Order A&. Int., B, i998, %, (7), 3785.
05
NUCLEAR
No. DA9738602.
of
From Diss.
FUELS
Process control for producing carbon products from coke-pitch mixtures
9BlOl270
Avramenko, P. Y. and Vlasov, E. E. Russ. RU 2,085,485 (Cl. COlB31/04), 27 Jul 1997, SU Appl. 5,061,400, 3 Sep 1992. From Izobreteniyu 1997, (21), 265. (In Russian)
Production of active carbon from Agacli lignite 9BlOl271 Aksu, F. et al. Chim. Acta Turc., 1997, 25, (2), 67-72. (In German) Active carbon is produced using agacli coal (lignite), by chemical activation at higher temperatures (400-1000°C) with saturated ZnClz and Cat& solutions. An optimum temperature interval of 500-600°C was obtained. Adsorption of methylene blue from the solution occurred according to the BET equation and the surface area of the active carbon was -350 m’/g.
112
Fuel and Energy Abstracts
March 1996
Scientific,
Technical
96lO1260 Applicability of carbonationldecarbonation tlons for storing thermal energy from nuclear reactors
reac-
Kyaw, K. et al. JAERI-Conf: 1996, 96-010, 408-420. So far, heat energy extracted from nuclear reactors has only been used for power generation. Recently, cleaner fuels such as hydrogen and methanol are being considered as strong possibilities for resolving global warming and oil shortage problems. From the view point of best energy mixing or highly developed energy system, it is important to study the possibility of making