Study on the Composition and Interface of Waste Silicon Slag After Secondary Refining

Abstract

Silicon slag is a secondary refining by-product from industrial silicon. The content of industrial silicon in silicon slag is about 20 %, which has extremely high economic value. To better achieve the recovery and reuse of industrial silicon slag, the morphology of industrial silicon slag, the occurrence state of elements and especially the interfacial structure between silicon and slag were deeply studied. The results showed that the purity of silicon particles in silicon slag is high up to 99 %. The interface between silicon and slag is clear and there is no obvious two-phase transition zone, which is beneficial to realize the recycling of silicon by breaking the silicon slag. The dissociated silicon slag was screened out for melting and refining. The results showed that the silicon phase was separated from the slag phase. In this paper, the physical and chemical properties of industrial silicon slag were studied, which provides a theoretical basis for the efficient separation and recovery of silicon in the slag.