According to Sina data. Com, as of February 2, 2023, historically, the State Reserve Bureau only sold copper stocks at the end of 2005, and has been collecting and storing copper since 2006, and has never sold copper.

Crude copper (containing 99% copper) is made into thick plate as anode, pure copper is made into thin plate as cathode, and mixed solution of sulfuric acid and copper sulfate 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, electrons are obtained, and pure copper is precipitated at the cathode, also called electrolytic copper.