Removal of iron and aluminum impurities from metallurgical grade-silicon with hydrometallurgical route

摘要

A new method for production of solar grade silicon(SoG-Si) at low cost from metallurgical grade silicon(MG-Si) via vacuum metallurgical technique was proposed,which is a promising process to feedstock solar energy silicon material independence of traditional Siemens method. In this procedure,pre-treatment of MG-Si using hydrometallurgical routes to remove the metallic impurities such as iron and aluminum to reduce the production cost is an important process. The influences of acid agents,acid concentration,reaction time and temperature and particle size of raw material ground on the removal efficiency of iron and aluminum impurities were investigated,respectively. The results show that the optimum operation conditions for leaching in acid C are:acid concentration 6 mol/L,temperature 60 ℃,time 4 d,diameter for raw material 50 μm. The removal efficiencies of impurities iron and aluminum are up to 85% and 75%,respectively.