Abstract: 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%.

Key words: aluminothermic reduction, molten salt electrolysis, silica, cryolite, Al-Si alloy