Si purification by solidification of Al–Si melt with super gravity

Abstract

The investigation on purification of metallurgical grade silicon by solidification of hypereutectic Al-Si melt with super gravity as an intensified separation way was carried out. The results indicate that the refined silicon grains are successfully enriched at the bottom of the Al-Si alloy along the direction of super gravity. Then the refined silicon was collected by aqua regia leaching. The purity of the collected silicon is analyzed as 99.92%, which is obviously improved compared with the purity of the metallurgical grade silicon of 99.59%, proving the feasibility of this purification method. Furthermore, the mass fraction of B is reduced from 8.33×10−6 to 5.25×10−6 and that of P from 33.65×10−6 to13.50×10−6.