Q. What is the Electrometallurgy?

The above two metallurgical processes, namely pyrometallurgy and hydrometallurgy can be used in the extraction of a fairly large number of metals. These processes, thus, cannot be used in cases:

• Where the metal is extremely reactive, e.g., Li, Na, etc. There are not any chemical-reducing - agents strong enough to make these metals
• Where the oxide gets reduced only at high temperatures at which preparation of carbides also takes place, e.g., Mg, Al, etc.

In these cases, metals can be extracted by electrolysis of their salts in molten state. Thus, magnesium and sodium are generated by electrolysis of fused chlorides, where the metals re Iiberated at the chlorine and cathode gas is evolved at the anode. Given reactions take place in the mean while electrolysis:

Anode: 2Cl^- ---------> Cl₂ (g) + 2e

Cathode: 2Na⁺ 2e ------> 2Na (l)

Mg²⁺ + 2e---------------> Mg (l)