Purification of Metallurgical Grade Silicon by Slag and Acid Leaching Treatment

Abstract

There are many methods of refining of metallurgical grade silicon (MG-Si). In this paper, the purification of MG-Si by slag and acid leaching treatment respectively is investigated. It is found that the main metallic impurities in MG-Si, such as Fe、Al、Ca、Ni、Ti，and nonmetallic elements, such as P、B, precipitated in Si-Ca phase, which is dissolved by acid easily. The influence of different ratio of slag/silicon upon removal rate of boron also be researched As well as, the effect of the cooling speed of the molten silicon on removal of P by acid treatment is researched and it indicated that the slower of cooling speed, the best effect removal of P is up to,There are many methods of refining of metallurgical grade silicon (MG-Si). In this paper, the purification of MG-Si by slag and acid leaching treatment respectively is investigated. It is found that the main metallic impurities in MG-Si, such as Fe、Al、Ca、Ni、Ti，and nonmetallic elements, such as P、B, precipitated in Si-Ca phase, which is dissolved by acid easily. The influence of different ratio of slag/silicon upon removal rate of boron also be researched As well as, the effect of the cooling speed of the molten silicon on removal of P by acid treatment is researched and it indicated that the slower of cooling speed, the best effect removal of P is up to