Bauxite is concentrated by Leaching (Baeyer’s process). The impure bauxite is treated with concentrated NaOH, Al2O3 and SiO2 dissolve, but Fe2O3 and other basic materials remain insoluble and are removed by filtration.
Aluminium is highly reactive metal, belonging to the III A group of the periodic table. In nature, aluminium is found in the form of its oxide in its ore. Hence, Magnetic separation is not used during the dressing of bauxite ore in the extraction of aluminium.
