Coal tar was extracted from Garin Maiganga and Shankodi coals by fixed bed pyrolysis process carried out between 325°C and 600°C at heating rate of 10°C/min and holding time of 30 min. The tar yield det...Coal tar was extracted from Garin Maiganga and Shankodi coals by fixed bed pyrolysis process carried out between 325°C and 600°C at heating rate of 10°C/min and holding time of 30 min. The tar yield determined was 31.95% for Shankodi and 17.02% Garin Maiganga. The obtained coal tar samples have the viscosity of 17.5 and 18.0 cP while the density was 0.9119 and 0.9156 g/cm3 for Garin Maiganga and Shankodi respectively. The solubility of all the coal samples in solvents such as water, benzene, alcohols, acetone, ether and chloroform is similar to the standard tar. The Gas Chromatography-Mass Spectroscopy (GC-MS) was used to analyse the coal tar components. The analysis result showed that the coal tar contained over 48 chemical compounds for Garin Maiganga and over 50 compounds for Shankodi. Benzo and naphthalene compounds were present in all the coal tar samples and these chemicals have wide industrial application.展开更多
On the basis of analyzing some limitations in the existing algorithm, a modified Monte Carlo methodwas proposed to simulate two-dimensional normal grain growth. With the modified method. the simulated time exponent of...On the basis of analyzing some limitations in the existing algorithm, a modified Monte Carlo methodwas proposed to simulate two-dimensional normal grain growth. With the modified method. the simulated time exponent of grain growth attained n=0.49±0.01, which is very close to the theoretical value of the steady graingrowth n=0.5, indicating the possibility to investigate the total process of normal grain growth. The relationbetween the Hillert and the von Neumann equations were studied and identified, the Hillert's basic equation hasbeen found to hold during the normal grain growth. The grain size distribution was found to van continuouslyand slowly with the simulated time in the total growth process, the lognormal and the Hillert functions may betwo types of the expression forms during its transition, and the later seemingly corresponds at the distribution ofthe steady stage were n≈0.50.展开更多
文摘Coal tar was extracted from Garin Maiganga and Shankodi coals by fixed bed pyrolysis process carried out between 325°C and 600°C at heating rate of 10°C/min and holding time of 30 min. The tar yield determined was 31.95% for Shankodi and 17.02% Garin Maiganga. The obtained coal tar samples have the viscosity of 17.5 and 18.0 cP while the density was 0.9119 and 0.9156 g/cm3 for Garin Maiganga and Shankodi respectively. The solubility of all the coal samples in solvents such as water, benzene, alcohols, acetone, ether and chloroform is similar to the standard tar. The Gas Chromatography-Mass Spectroscopy (GC-MS) was used to analyse the coal tar components. The analysis result showed that the coal tar contained over 48 chemical compounds for Garin Maiganga and over 50 compounds for Shankodi. Benzo and naphthalene compounds were present in all the coal tar samples and these chemicals have wide industrial application.
文摘On the basis of analyzing some limitations in the existing algorithm, a modified Monte Carlo methodwas proposed to simulate two-dimensional normal grain growth. With the modified method. the simulated time exponent of grain growth attained n=0.49±0.01, which is very close to the theoretical value of the steady graingrowth n=0.5, indicating the possibility to investigate the total process of normal grain growth. The relationbetween the Hillert and the von Neumann equations were studied and identified, the Hillert's basic equation hasbeen found to hold during the normal grain growth. The grain size distribution was found to van continuouslyand slowly with the simulated time in the total growth process, the lognormal and the Hillert functions may betwo types of the expression forms during its transition, and the later seemingly corresponds at the distribution ofthe steady stage were n≈0.50.
