Bismuth is mainly used to make fusible alloys, and in the fire protection and electrical industry, it is used as automatic fire extinguishing system, electrical fuse and soldering tin. Bismuth alloy has the characteristic of non shrinkage during solidification, and is used for casting printing type and high-precision mold. Bismuth oxycarbonate and bismuth oxynitrate are used to treat skin injuries and gastrointestinal diseases.