Q. Extraction of Aluminium?

Aluminium cannot be extirpated economically from the silicate minerals. Therefore bauxite is the most important ore for the extraction of alumimum, but this has many problems. Al₂0₃ is a very stable compound. It is not reduced by heating in hydrogen.  On strong heating with carbon, Al₂0₃, gives the carbide, AI₄,C₃,. As Al₂0₃ does not melt below 2300 K, it cannot be electrolysed conveniently. However, electrolysis of a solution of A120, in fused cryolite occurs at a much lower temperature of 1100-1300 K. Thus, aluminium is extracted by electrolysis of purified alumina in fused cryolite.