冰晶石熔盐介质中铝热还原-熔盐电解二氧化硅

讨论了铝热还原二氧化硅的热力学条件,热力学计算结果表明铝热还原二氧化硅的反应在热力学上可行.差示扫描量热法分析结果表明,铝热还原二氧化硅反应的表观活化能为697.5 k J/mol,反应级数为3.7.在冰晶石熔盐介质中铝热还原二氧化硅,可得到含8.56%硅的铝硅合金及富氧化铝的冰晶石熔盐;使用惰性阳极电解分离后的富氧化铝的冰晶石熔盐,可得到含94.01%铝的铝硅合金及氧气,硅的回收率为83.43%.

Aluminothermic Reduction-Molten Salt Electrolysis of Silica in Cryolite Melts

The thermodynamic conditions for the aluminothermic reduction of the silica were discussed. The thermodynamic calculation results showed that reducing silica by aluminum is thermodynamically feasible. The kinetic analysis by non-isothermal differential scanning calorimetry indicated that the apparent activation energy was 697.5kJ/mol， while the reaction order was 3.7. Al-Si alloy including 8.56%silicon and the alumina-rich cryolite were obtained by the aluminothermic reduction of silica in cryolite molten salt medium. Al-Si alloys contained 94.01%aluminum and oxygen were produced using the alumina-rich cryolite molten salts separated by the inert anode， and the recovery rate of silicon was 83.43%.