Copper has good electrical conductivity, thermal conductivity, ductility, deep drawing and corrosion resistance. The electrical conductivity and thermal conductivity of copper is second only to silver, and it is widely used to make electrical and thermal equipment. Copper has good corrosion resistance in the atmosphere, sea water, some non-oxidizing acids (hydrochloric acid, dilute sulfuric acid), alkali, salt solution and a variety of organic acids (acetic acid, citric acid), and is used in the chemical industry. In addition, copper has good weldability and can be processed into various semi-finished and finished products through cold and thermoplastic processing.