Physical properties of cobalt: cobalt is a shiny steel gray metal with melting point of 1493 ℃ and specific gravity of 8.9. It is relatively hard and brittle. Cobalt is ferromagnetic and is similar to iron and nickel in hardness, tensile strength, machinability, thermodynamic properties and electrochemical behavior. When heated to 1150 ℃, the magnetism disappears.

Chemical properties of cobalt: the valence of cobalt is 2 and 3. It does not work with water at room temperature and is stable in humid air. When heated to more than 300 ℃ in air, COO is formed by oxidation and burned into coo in white heat. The fine metal cobalt powder prepared by hydrogen reduction can spontaneously ignite into cobalt oxide in air.

1. Cobalt base alloy or cobalt containing alloy steel is used as blades, impellers, ducts, parts of jet engines, rocket engines and missiles of gas turbines, various high load heat-resistant parts in chemical equipment and important metal materials in atomic energy industry.

2. As a binder in powder metallurgy, cobalt can ensure that cemented carbide has a certain toughness. Magnetic alloy is an indispensable material in modern electronic and electromechanical industry. It is used to manufacture various components of acoustic, optical, electrical and magnetic equipment.

3. Cobalt is also an important part of permanent magnetic alloys. In the chemical industry, cobalt is not only used in superalloys and anti-corrosion alloys, but also used in colored glass, pigments, enamel, catalysts, desiccants, etc.