Impurity Removal from Diamond-Wire Cutting Waste by Slag Refining and Electromagnetic Stirring

Abstract

This paper proposes a method of recycling and purifying silicon from diamond-wire cutting waste by a combined process of slag refining and electromagnetic stirring. A slagging agent of calcium silicate containing barium oxide was added to the diamond-wire cutting waste. Different experimental conditions were carried out for silicon separation and purification. Owing to the difference of affinity between impurity elements and oxygen, the elements with high oxygen affinity combined with oxygen and changed into oxides, which entered into the slag phase. The separation of silicon and slag in the melt was realized through electromagnetic stirring in a medium frequency induction furnace. The experimental results show that this proposed refining method can remove impurities more effectively from diamond-wire cutting waste. It was also found that the mass ratio of slag to silicon has a significant effect on the separation efficiency of silicon.