Electrochemistry Purifying Copper and Isolating Aluminum

Industrial Electrochemistry Purifying Copper and Isolating Aluminum 

In addition to the Downs cell for sodium production and the chlor-alkali process for chlorine manufacture, industrial methods based on voltaic and electrolytic cells are used commonly to obtain metals and nonmetals from their ores or to purify them for later use. Here we focus on two key electrochemical processes. 

The Electrorefining of Copper The most common copper ore is chalcopyrite, CuFeS2, a mixed sulfide of FeS and CuS. Most remaining deposits contain less than 0.5% Cu by mass. To win this small amount of copper from the ore 

CHAPTER 21 Electrochemistry Chemical Change and Electrical Work 

Copper and the more active impurities (Fe, Ni) are oxidized to their cations, while the less active ones (Ag, Au, Pt) are not. As the anode slabs react, these unoxidized metals fall off as a valuable anode mud and are purified separately. Sale of the precious metals in the anode mud nearly offsets the cost of electricity to operate the cell, making Cu wire inexpensive. 

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