Refining consists of removing any metal impurities from the copper. This process increases the purity of the copper from 99 to 99.9%. A meagre 0.9% that nonetheless doubles the value of the metal.
The copper anodes are immersed in a cell containing chemicals and a thin sheet of pure copper called a "starter sheet" or cathode is inserted between each anode.
When connected to an electric current, the anodes dissolve and the copper collects on the starter sheets. The whole cell is like a huge battery and a full cycle takes 21 to 28 days.
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The copper produced is then cast into bars and sold.
The impurities that settle at the bottom of the cells are valuable elements such as gold, silver and other precious metals.
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