Copper is a non-ferrous metal closely related to human beings. It is widely used in electrical, light industry, machinery manufacturing, construction industry, national defense industry and other fields. It is second only to aluminum in the consumption of non-ferrous metal materials in China. Copper is a red metal as well as a green metal. It is said that it is a green metal, mainly because it has a low melting point and is easy to remelt and remelt, so it is quite cheap to recycle.