White bauxite is purified by: Toppr
Solution. Verified by Toppr. White bauxite containing the impurity of silica only in removed by heating with coke in atmosphere of nitrogen. Al2O3 +3C+N 2 Δ −→ 2AlN +3CO. SiO2 +2C Δ −→ Si +2CO ↑; AlN +H 2O → Al(OH)3 +N H 3; 2Al(OH)3 Δ −→ Al2O3 +H 2O. Other process are used for extraction of Al from red bauxite.