Electro-refining is a process used to purify metals, particularly those that are too reactive to be extracted by traditional methods. This technique utilizes electrolysis to remove impurities from the metal, resulting in high-purity metal.

Activity:

Electrolytic refining of copper can be done, where anode is impure copper and cathode is a thin strip of pure copper. The electrolyte used for the process is the copper sulphate solution.

When electric current is passed through the electrolyte, the impure copper from the anode is dissolve in the electrolyte and an equal amount of pure copper from the electrolyte is deposited on the cathode.

The soluble impurities go into the solution whereas the insoluble impurities settle down at the bottom of the anode which is known as anode mud.

In this way, copper can be refined through electro-refining.