Electrolytic copper
The crude copper (containing 99% copper) will be made into thick plate as anode in advance, pure copper made into thin slice as cathode, with sulfuric acid (H2SO4) and copper sulfate (CuSO4) of the mixture of liquid as electrolyte. After energized, copper from the anode dissolved into copper ions (Cu) to the cathode to move to the cathode, after arriving at the cathode to obtain electrons and precipitate pure copper at the cathode (also known as electrolytic copper). Crude copper impurities such as iron and zinc, which are more active than copper, are dissolved into ions (Zn and Fe) along with copper. Since these ions are not easy to precipitate compared to copper ions, electrolysis can avoid the precipitation of these ions at the cathode by adjusting the potential difference appropriately. Than copper inactive impurities such as gold and silver deposited at the bottom of the electrolyzer. The copper sheet produced in this way is called "electrolytic copper" and is of such high quality that it can be used to make electrical products.
Precision casting
Precision casting is a general term for the process of obtaining accurate castings using precise molding methods.