What is Electrowinning of Base Metals?

What is Electrowinning of Base Metals?

Electrowinning is one of the main methods to recover base metals from solutions. Electrowinning is commonly used in the production of copper, zinc, and nickel, but it is also applied in the production of cobalt and noble metals.

In electrowinning metal is dissolved from the starting material using chemical or electrochemical leaching, the solution is purified from impurities that can disturb the deposition process, and metals are recovered using direct current. The deposition substrate can be same material as the deposited metal like starting sheets for copper or nickel. The substrate can also be a permanent material onto which the metal is deposited and then mechanically stripped of like stainless steel in copper production or aluminum in zinc production.

The task of the anode is to maintain anodic reactions that in electrowinning of metals are typically oxygen evolution and chlorine evolution. The anode should be chemically and electrochemically stable and operate at low overpotential.