Hydrometallurgy - An Overview

Hydrometallurgy is the process of removing impurities from and ore by treating it with a liquid solution. 

There are three steps to this process.  They are

The ore is immersed in the solution or in certain cases, the aqueous solution is pumped into the deposits.  After the reaction with the ore is complete.  The solution leaches from the deposits where it is collected or pumped out.

Concentration of the Solution and purification
The leached solution contains the required metal.  This has to be removed.  This can by done using chemical process such as precipitation, solvent extraction, ion exchange, etc.  The desired metal is now obtained.

Metal Recovery
The metal recovered may not be in the desired purity.  To increase the purity, the metal is subject to electrolysis with the impure metal as the anode.  The pure metal is obtained at the cathode