Low-Temperature Synthesis of the β-SiC Particle by Microwave Heating of Solar Waste Silicon Powder

The solar waste silicon powder generated by the cutting of crystalline silicon was used as the raw materials, and silicon carbon was synthesized by the microwave heating method. The temperature-raising characteristics of silicon powder by microwave heating and the effects of temperature and holding time on the formation of β-SiC particles were investigated. The formation mechanism of the β-SiC particle was further studied. Results showed that β-SiC particle with diameters of 1–3 μm was formed in the products, and the yield of β-SiC in the products was more than 95% at 800 ℃ for a holding time of 30 min. The microwave heating decreases the reaction temperature and greatly shortens the reaction time. The local microwave plasma activated by the microwave electromagnetic field promotes the nucleation and growth of β-SiC particles. It realizes the recovery and utilization of industrial solar waste silicon powder, and the microwave heating technology effectively saves energy consumption.