Smelting Process
Madras Aluminium Company Ltd. (MALCO) uses VSS (Vertical Stud Soderberg) technology to produce Aluminium from Alumina. Alumina is dissolved in an electrolytic bath of molten cryolite (Sodium Aluminium Fluoride) within a large carbon or graphite lined steel container known as a "Cathode". An electric current is passed through the electrolyte at low voltage, but very high current. The electric current flows between a carbon anode (positive), made of petroleum coke and pitch, and a cathode (negative), formed by the thick carbon or graphite lining of the pot. Molten Aluminium is deposited at the bottom of the pot and is siphoned off periodically. It is then taken to a holding furnace, cleaned and then cast.

Smelter
MALCO has a 40,000 tpa smelter at the Mettur Dam complex.