Aluminium extraction

Alumina is extracted from bauxite ore using Bayer process. 

Bauxite is crushed into grains. 

Then mixed with liquor from the later precipitation stage and crushed again to make a slurry. 

Bauxite can have a high level of silica present, so it may have to go through the desolation to remove this. 

Hot sodium solution is used to dissolve the aluminium bearing minerals. 

Conditions for this change due to the composition of the bauxite ores. 

Those with a high gibbsite content need around 140 degrees celsius, while those with a high bohmitic content need a higher temperature (200 - 280 degree celsius)

Slurry is cooled to around 106 degree celsius. 

Solids are separated from…