How is copper purified by electro - refining ?

Explanation

Electrorefining method is one of the important methods used for the purification of the metals such as Cu. An aqueous solution of `CuSO_4` is used as an electrolyte.
Impure metal acts as an anode and pure copper sheet acts as cathode. When elec.tricity is passed through the electrolyte, pure metal gets deposited on the cathode whereas the impurities settle down in the form of mud near the anode.

At cathode : `Cu^(2+) + 2e^(-) to Cu` (Reduction occurs)
At anode : `Cu to Cu^(2+) + 2e^(-)` (Oxidation occurs)