Electrolytic copper

Crude copper (containing 99% copper) was pre-made into a thick plate as the anode, pure copper was made into thin plates as the cathode, and a mixture of sulfuric acid and copper sulfate was used as the electrolyte. After electrification, copper dissolves from the anode into copper ions (Cu) and moves towards the cathode. After reaching the cathode, electrons are obtained and pure copper is precipitated at the cathode (also known as electrolytic copper). Impurities in crude copper such as iron and zinc, which are more active than copper, will dissolve into ions (Zn and Fe) along with copper. Since these ions are less likely to precipitate than copper ions, the precipitation of these ions on the cathode can be prevented by appropriately adjusting the potential difference during electrolysis. Impurities less reactive than copper, such as gold and silver, are deposited at the bottom of the electrolytic cell. The copper plate produced in this way is called "electrolytic copper".