Available silicone was melted from coal gangue samples from Hancheng dig- gings through calcination, digestion, and other means. The best calcination temperature was determined from a range of 550-1 150 ℃; and the be...Available silicone was melted from coal gangue samples from Hancheng dig- gings through calcination, digestion, and other means. The best calcination temperature was determined from a range of 550-1 150 ℃; and the best time, from a range of 0.5-5 h by colorimetry method. The proper ratio of coal gangue, limestone, sodium carbonate, and caustic soda was then determined through orthogonal experiment. The results show that the proper extraction condition for available silicone is the ratio of coal gangue, limestone, sodium carbonate, and caustic soda at 1:0.5:0.1:0.05, calcination temperature at 700 ℃, and calcination time at 2 h. In this condition, the available silicone content can be more than 19.65%.展开更多
The volatilization kinetics of senarmontite(Sb_2O_3) was analyzed in a neutral atmosphere in two temperature ranges: 550-615 °C(roasting temperature) and 660-1100 °C(melting temperature) by using a th...The volatilization kinetics of senarmontite(Sb_2O_3) was analyzed in a neutral atmosphere in two temperature ranges: 550-615 °C(roasting temperature) and 660-1100 °C(melting temperature) by using a thermogravimetric analysis method under various gas flow rates and using a 1.3 m L ceramic crucible(11 mm in internal diameter and 14 mm in height). The effect of particle size was also analyzed. The experimental results of mass loss data, X-ray diffraction(XRD) analysis of partially reacted samples and thermodynamic studies indicate that the senarmontite becomes volatile in the form of Sb_4O_6(g) without the formation of any intermediary compound in the entire temperature range. At roasting temperatures, the volatilization kinetics of Sb_2O_3 was analyzed using the model X=kappt. The volatilization reaction was controlled by the surface chemical reaction and an activation energy value of 193.0 k J/mol was obtained in this temperature range. Based on the volatilization kinetics at the melting temperatures, for linear behaviour in nitrogen gas, kinetic constants were determined, and an activation energy of 73.9 k J/mol was calculated for the volatilization reaction with a surface area of 8.171×10^(-5)m^2.展开更多
基金Supported by Education Department Project of Shannxi Province(06JK238)
文摘Available silicone was melted from coal gangue samples from Hancheng dig- gings through calcination, digestion, and other means. The best calcination temperature was determined from a range of 550-1 150 ℃; and the best time, from a range of 0.5-5 h by colorimetry method. The proper ratio of coal gangue, limestone, sodium carbonate, and caustic soda was then determined through orthogonal experiment. The results show that the proper extraction condition for available silicone is the ratio of coal gangue, limestone, sodium carbonate, and caustic soda at 1:0.5:0.1:0.05, calcination temperature at 700 ℃, and calcination time at 2 h. In this condition, the available silicone content can be more than 19.65%.
文摘The volatilization kinetics of senarmontite(Sb_2O_3) was analyzed in a neutral atmosphere in two temperature ranges: 550-615 °C(roasting temperature) and 660-1100 °C(melting temperature) by using a thermogravimetric analysis method under various gas flow rates and using a 1.3 m L ceramic crucible(11 mm in internal diameter and 14 mm in height). The effect of particle size was also analyzed. The experimental results of mass loss data, X-ray diffraction(XRD) analysis of partially reacted samples and thermodynamic studies indicate that the senarmontite becomes volatile in the form of Sb_4O_6(g) without the formation of any intermediary compound in the entire temperature range. At roasting temperatures, the volatilization kinetics of Sb_2O_3 was analyzed using the model X=kappt. The volatilization reaction was controlled by the surface chemical reaction and an activation energy value of 193.0 k J/mol was obtained in this temperature range. Based on the volatilization kinetics at the melting temperatures, for linear behaviour in nitrogen gas, kinetic constants were determined, and an activation energy of 73.9 k J/mol was calculated for the volatilization reaction with a surface area of 8.171×10^(-5)m^2.