Methods to remove impurities from silicon carbide powder
During the smelting and crushing process of silicon carbide, it is inevitable to produce graphite electrode residues, raw material residues, free carbon, free silicon and other impurities. Therefore, these impurities need to be removed in the subsequent process.
There are several methods to remove impurities from Silicon carbide powder:
1. Wash with water. Water washing can remove graphite, dust, etc.
2. Alkali washing. Alkali washing mainly removes free silicon and silicon dioxide from impurities. However, alkaline washing is not conducive to environmental protection, and currently the silicon content is mainly controlled by controlling the smelting process.
3. Acid washing. Acid washing of silicon carbide powder can remove impurities such as iron oxide, aluminum oxide, magnesium oxide, and graphite. Re washing after acid washing can lower the pH value of silicon carbide powder and improve its flowability.
