A Low-Cost and Facile Method to Recycle Silicon Carbide Particles from the Solar Grade Silicon Slicing Wastes

摘要

Solar grade silicon slicing wastes (SoG-Si-w) are the byproducts of the photovoltaic industry, which are the precious sources of SiC particles and high-purity silicon. Herein, we report a low-cost and facile approach to recover the SiC particles by the methods of physical sedimentation and chemical technique. The effects of reaction time, reaction temperature, acid concentration, stirring speed and liquid-solid ratio on the purity of SiC were discussed in details. The results indicated that the optimal reaction conditions were as follows: mixed acid solution of 5 wt% HF and 8 wt% HNO3, reaction time of 2 h, temperature of 60 degrees C and liquid-solid ratio of 5:2. SiC particles with the purity of 98.54 wt% with grain sizes of 1.2 similar to 11.4 mu m were obtained, which could match the standards of SiC abrasives. It is promising that the current work could provide a low-cost and facile method for recycling SiC particles from SoG-Si-w, which could also reduce the cost for solar cells and facilitate the recycling of high-purity silicon from SoG-Si-w.