Some of the important industrial applications of electrolysis are as under.
Many of the highly reactive metals such as metal of group 1 or group 2 are extracted from their ores by electrolysis of their molten ores. This is because chemical reduction of their compounds .is either chemically not viable or highly expensive. Metals like sodium and magnesium, are manufactured by the electrolysis of their molten chlorides. Pure aluminium is obtained at Valco Industry from a solution of its oxide in molten cryolite. Details of this extraction and that of some other metals is discussed in later units.
ELECTROREFINING OF METALS
Refining of many of the crude metals such as copper, silver; aluminium, etc. is carried out by the process of electrolysis. In this. process, the block of crude metal is made anode while a thin sheet of pure metal is made cathode and the electrolyte is aqueous solution of some salt of the metal. As the electrolysis proceeds metal from anode dissolves whereas it gets deposited in pure form at cathode. The impurities settle down just below anode in the form of anode sludge or anode mud.
MANUFACTURE OF CHEMICAL SUBSTANCES
Electrolysis is used in the manufacture of some important substances such as hydrogen, chlorine, sodium hydroxide, sodium oxochlorate (I) and oxygen.