Sterlite Industries (India) Limited - Sterlite Industries India Ltd.

Additional Supply of Alumina
The additional alumina required for BALCO’s smelters in excess of the capacity of its alumina refinery is obtained by purchasing alumina
on both the domestic Indian market, including from Vedanta Aluminium, and international markets. Alumina purchased from third party
suppliers is transported by road to BALCO’s smelters at Korba. In addition, BALCO also sends bauxite to Vedanta Aluminium for conversion
into alumina, which is returned to BALCO for use in its smelters, for which a conversion fee linked to market rates is paid to Vedanta
Aluminium.
Aluminum Smelters
BALCO’s 245,000 tpa aluminum smelter uses pre-baked technology from GAMI of China. In this pre-baked process, alumina is converted
into primary aluminum through a smelting process using electrolytic reduction. The reduction process takes place in a reduction cell, referred to
as the pot, where alumina is reduced to molten aluminum. From the pot-line, the molten aluminum is sent to the fabrication facility.
During fiscal 2009 and until June 5, 2009, BALCO also operated a 100,000 tpa aluminum smelter that uses Vertical Stud Soderberg, or
VSS, technology to produce aluminum from alumina. Alumina is dissolved in an electrolytic bath of molten cryolite (sodium aluminum
fluoride) in a large carbon or graphite lined steel container known as a “pot.” An electric current is passed through the electrolyte at low voltage
but at a 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 aluminum is deposited at the bottom of the pot and is siphoned off
periodically. The molten aluminum is then taken to a holding furnace, cleaned and sent to the fabrication facility. In response to recent global
economic conditions and a decline in commodity prices, starting in February 2009, BALCO suspended part of its operations at the 100,000 tpa
aluminum smelter. Operations at this aluminum smelter ceased on June 5, 2009. The surplus power generated by the captive power plants at the
Korba facility is sold to the CSEB and other third parties.
Fabrication Facility
BALCO’s fabrication facility, consisting of a cast house and a sheet rolling shop, processes the molten aluminum from the smelters into
ingots, wire rods and rolled products. The cast house uses continuous rod casters from Continuus-Properzi S.p.A. and has a foundry which has
twin-roll continuous casters with a spinning nozzle inert flotation, or SNIF, degasser and hydraulically driven semi-continuous ingot casting
machine to produce ingots and wire rods. Molten metal is cast into slabs and either hot-rolled and sold as hot-rolled sheets or converted into
cold-rolled sheets in the cold rolling mills. Alternatively, molten metal is directly used in strip casting and then fed to the cold rolling mills to
convert it into cold-rolled sheets or coils.
Delivery to Customers
Ingots, wire rods and rolled products are transported by trucks to customers in India and to ports for export.
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