低价硫化铝法从氧化铝直接炭还原制铝的动力学研究  

Dynamics Study of Al Extraction from Al_2O_3 by Al Sub-sulphidization

作　　者：吴国元[1] 刘大春[2] 戴永年[2] 

机构地区：[1]云南大学材料科学与工程系,昆明650091 [2]昆明理工大学冶金系,昆明650093

出　　处：《真空科学与技术学报》2004年第4期263-266,270,共5页Chinese Journal of Vacuum Science and Technology

摘　　要：低价硫化铝法从氧化铝直接炭还原制铝的动力学过程极为复杂 ,过程的前期受界面化学反应控制 ,过程后期受扩散过程控制 ,并求得不同时期的活化能 ,反应前期 :E1=6 3 81kJ/mol(6 6 7Pa)、E2 =5 0 82kJ/mol(6 6 7Pa)、E3 =5 4 72kJ/mol(6 6 6 7Pa)、E4=39 6 1kJ/mol(1333Pa) ;反应后期 :E 1=112 90kJ/mol(6 6 7Pa)、E 2 =89 92kJ/mol(6 6 7Pa)、E 3 =97 32kJ/mol(6 6 6 7Pa)、E 4=5 1 83kJ/mol(1333Pa)。从动力学的角度提出了反应的较佳条件。温度、真空度的提高一方面可增大反应速率 ,但另一方面却加大了硫化铝的挥发 ,仅从增大速率而言 ,温度应大于 110 0℃ ,真空度应优于 1333Pa为宜。The rather complicated dynamic process in Al extraction from Al 2O 3 by Al Sub-sulphidization was studied to optimize the production conditions.The early stage is found to be dominated by interfacial reactions,whereas the final stage is strongly affected by diffusing.The activation energies at various stages were evaluated,respectively.Though high temperature and low pressure significantly increase the reaction rate,serious volatilization of Al 2S 3 could be a problem.We suggest that a temperature above 1100 ℃ and a pressure lower than 1333 Pa result in higher reaction rates.

关 键 词：扩散过程 界面化学 动力学过程 还原 活化能 反应速率 动力学研究 氧化铝 硫化 挥发 

分 类 号：TB324[一般工业技术—材料科学与工程] TF821[冶金工程—有色金属冶金]