Promotion of silicon–oxygen control and green sustainable recovery from diamond wire saw silicon powder waste based on the viscous flow mechanism

Abstract

Diamond wire saw silicon powder (DWSSP) waste is a highly promising secondary resource for recycling high-purity silicon, which is crucial for the sustainable development of the photovoltaic (PV) industry. However, because DWSSP is prone to oxidation, the purity and yield of the recovered silicon are generally low. In this study, the oxidation mechanism of DWSSP in water was systematically investigated, and kinetics analysis and microstructure analysis were conducted to determine the relationship between water diffusion and the growth of the oxide layer. The results indicated that oxidation was determined by the kinetic parameter b in the Reisman model. At T < 328 K and particle size > 1.56 μm, b was less than 1, indicating that the oxidation process was governed by the diffusion of H2O molecules. Through temperature regulation to achieve b < 1, the oxidation was inhibited, which could enhance recovery efficiency. Overall, this study demonstrated the feasibility of inhibiting oxidation by regulating the viscous flow of SiO2 molecules to promote the recycling of silicon resources and support sustainable development.