Aluminum Smelting Process
Aluminium smelting is the process of extracting aluminium from its oxide, alumina, generally by the Hall process. Alumina is extracted from the ore bauxite by means of the Bayer process at an alumina refinery. Aluminium smelting is the 2nd most important metallurgical industry in India.
Aluminium production from bauxite ore is a three step process. First the alumina is extracted from bauxite ore usually using the Bayer Process. In the Bayer Process, finely crushed bauxite is mixed with sodium hydroxide and placed in a digester. The result is dissolved aluminium oxide and ore residue.
Smelting is a form of extractive metallurgy. Its main use is to produce a base metal from its ore. This includes production of silver, iron, copper and other base metals from their ores.
It takes about (2 kg) of bauxite to produce (0.5 kg) of aluminium metal. Aluminium is manufactured in two phases: the Bayer process of refining the bauxite ore to obtain aluminum oxide, and the Hall-Heroult process of smelting the aluminium oxide to release pure aluminium.
Introduction- Aluminium (Al) comprises about 8.2% of the Earth’s crust. It is the third most abundant element in the crust and the most plentiful metallic element, but is never found on its own in nature. Bauxite is the ore most commonly mined for aluminium in which aluminium occurs as hydroxide minerals.
Melting point Al: 933.57 K (660.32 o C)
The reported temperature for a bid lighter: 600 – 800 C.
Aluminium burns at over 4,100 K (6920°F)