Study on the Separation and Sedimentation Performance of Silicon from Diamond Wire Saw Silicon Powder Slurry

The rapid development of the photovoltaic industry has led to a dramatic increase in the production of silicon scrap waste, the recovery of high-purity silicon from silicon wafer-cutting scrap is crucial. Therefore, developing a fast and efficient separation method of for diamond wire saw silica powder slurry (DWSSPS) is necessary to achieve high recovery, high purity, and low oxidation rates. In this study, the separation of silicon from the slurry was facilitated by adjusting the pH, and temperature of the slurry and by adding additives to the slurry during the precipitation process. The experimental results showed that the surface potential of DWSSPS decreased from 30 to 3 mV at pH = 1 and with the addition of acetone. The result also showed that an increase in the temperature reduced the viscosity of the slurry, accelerating the separation rate of the particles from silicon waste. The optimal separation effect was achieved when the fluid activation energy was 15.97 kJ/mol. Therefore, particle in DWSSPS are more easily separated under acidic conditions, high temperatures, and acetone additive. Effective separation under these conditions can improve the recycling of silicon waste in the photovoltaic industry.