Thick plate made of crude copper (containing 99% copper) is used as anode, thin plate made of pure copper is used as cathode, and mixed solution of sulfuric acid (H2SO4) and copper sulfate (CuSO4) is used as electrolyte. After electrifying, copper is dissolved into copper ions (Cu) from the anode and moves to the cathode. After reaching the cathode, it gains electrons and precipitates pure copper (also called electrolytic copper) at the cathode. Impurities in crude copper, such as iron and zinc, which are more active than copper, will dissolve into ions (zinc and iron) with copper. Because these ions are not easy to precipitate compared with copper ions, they can be prevented from precipitating on the anode as long as the potential difference is properly adjusted during electrolysis. Impurities not as active as copper, such as gold and silver, are deposited at the bottom of the electrolytic cell. The copper plate produced by this method is called "electrolytic copper", which is of high quality and can be used to manufacture electrical products. Anode mud deposited at the bottom of electrolytic cell is called "anode mud", which is rich in gold and silver and valuable. It is of great economic value to take it out for further processing.

Shanghai Futures Exchange (SHFE)

Copper for futures trading

Standard product: standard cathode copper, which conforms to the national standard GB/T467- 1997. The main components of copper and silver are not less than 99.95%.

Substitute 1. High-purity cathode copper meets the national standard GB/T467- 1997 high-purity cathode copper;

2。 LME registered cathode copper conforms to BS6017-1981and AMD5725 standards (cathode copper grade code CU-CATH- 1).

London futures exchange (LME)

There are two kinds of copper in futures trading:

1, cathode grade copper: first grade copper. All delivered copper must have Grade A copper approved by the London Stock Exchange, which conforms to the British BS 6017-1981standard classification specification.

2. Copper rod: The specification standard is Grade A copper, and the weight is between 1 10- 125 kg.