Molybdenum is a kind of refractory rare metal (melting point is 2620℃). It has high structural strength at room temperature and high temperature, small expansion coefficient, high electrical conductivity and good thermal conductivity. It does not react with hydrochloric acid, hydrofluoric acid and alkaline solutions at room temperature, and only dissolves in nitric acid, aqua regia or concentrated sulfuric acid, and is quite stable to most liquid metals, non-metallic slags and molten glass. Therefore, molybdenum and its alloys have a wide range of applications in the fields of metallurgy, agriculture, electrical, chemical, environmental protection and aerospace.