摘要
从理论角度系统研究了Al2O3-C系、SiO2-C系、Al2O3-SiO2-C系热力学。结果表明,在Al2O3-C系中,碳热还原氧化铝过程的中间产物Al4C3,它与A12O3、A1之间有很大的溶解度,导致铝的提取率较低,给利用电热法直接制备金属纯铝带来了困难。在Al2O3-SiO2-C系中,硅在很大程度上改善了铝还原的热力学条件,其中间产物Al4C3、SiC等碳化物分别与SiO2、Al2O3反应进而生成铝-硅合金,使电热法生产铝-硅合金得以实现。动力学研究结果表明,在电热法生产铝-硅合金中,Fe的存在使铝-硅合金生成反应的起始温度大大降低,且Fe与Al、Si在熔融状态下可以无限互溶,Fe还有助于破坏碳热还原过程中容易生成的碳化物。
In this study, we theoretically studied the thermodynamics of Al2O3 -C, SiO2 -C and Al2O3 -SiO2 -C system. The intermediates AIa C3 from Al2O3 - C system had a high solubility with Al2O3 and Al, which reduced extraction efficiency and increased the difficult for producing pure aluminum by electrothermal process. In Al2O3 - SiO2 - C system, the thermodynamic conditions of reducing aluminium had been dramatically improved by silicon, and AI -Si alloy were synthesized by the reaction of intermediates （Al4 C3 and SiC） with SiO2 and Al2O3 , respectively, which made the industrialisation of Al - Si alloy by electrothermal method available. The kinetics study showed that He initial reaction temperature of Al - Si alloy had dropped significantly in the production process for Al - Si alloy by electrothermal method, which ascribed to the presence of Fe. While molten, Fe with AI and Si were absolutely miscible, and Fe also facilitated the destruction of carbide from carbothermic reduction.
出处
《轻金属》
CSCD
北大核心
2014年第3期48-53,共6页
Light Metals
关键词
电热法
铝硅合金
热力学
动力学
electrothermal method
Al - Si alloy
thermodynamics
kinetics
