Question

Explain electrorefining with a labelled diagram.

Answer 1

Electrorefining is a highly effective purification technique utilized for a wide variety of metals, including copper, silver, gold, lead, nickel, chromium, zinc, and aluminium. In this electrochemical process, a substantial block of the impure metal serves as the anode, while a thin plate or strip of the identical pure metal functions as the cathode. These electrodes are immersed in an electrolyte consisting of a soluble salt solution of the same metal.

When an electric current is passed through the system, pure metal systematically dissolves from the impure anode into the electrolyte and subsequently deposits onto the pure cathode plate. During this continuous transfer, any soluble impurities dissolve directly into the liquid solution, whereas the insoluble waste materials settle at the bottom of the container right below the anode, forming what is known as anode mud.