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 by properly adjusting the potential difference during electrolysis. Impurities that are 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.