The removal of phosphorus and boron by slag and acid leaching treatment

The rapid development of photovoltaic industry is causing many researches on the refining of silicon, especially the purification of silicon by metallurgical method from the metallurgical-grade silicon (MG-Si). The removal of phosphorus and boron is one of the major problems on the refining of MG-Si to Solar-grade silicon (SoG-Si). At present, the removal method of phosphorous and boron by slagging of CaO-SiO2-CaF2 and acid leaching treatment is being researched. It was found that the best removal ratio of phosphorous and boron could reach up to 81% and 92%. Meanwhile, the principle of removal of phosphorous and boron has been studied.