Rapid synthesis of sodium silicate through adiabatic reaction with low emission starting from exhausted KL-Si

Abstract

The kerf loss silicon (KL-Si) generated during the wafer slicing process in the photovoltaic industry is a resource that must be recycled. Compared to synthesizing sodium silicate from agricultural waste and other industrial methods, its synthesis from KL-Si has been very rare, but could be very effective. To recycle the industrial waste, a first-of-a-kind synthesis process of converting KL-Si into sodium silicate was developed. In this study, we presented a viable technique to synthesize sodium silicate from KL-Si waste by treating it with sodium hydroxide (NaOH) with a low water consumption rather than using conventional high-temperature techniques. The reaction occurred at elevated temperatures using its own exothermic reaction heat. Further, the modular number and sodium silicate concentration could be easily regulated, which resulted in an optimal conversion of the products. This synthetic method provided more than 98.5% conversion within an hour which was much higher and faster than the conventional methods. This synthesis method is highly efficient, eco-friendly, low emission, and low cost for rapid synthesis of sodium silicate.