General Principles And Processes Of Isolation Of Elements

Chief ore of aluminium is bauxite . Firstly bauxite is concentrated by chemical method. (Baeyer's method) using in which pure alumina is obtained. Bauxite has impurity of sand only reacts with Impurities remain in the solution. It is then filtered and the filterate is strongly heated This solution is again filtered to obtain white precipitate of which is strongly heated to obtain pure . Aluminium being highly electropositive is reduced by electrolytic reduction (Hall's process). During Hall's process alongwith molten small amount of cryolite and fluorspar are also added as they decrease the melting point of and increase its electrical conductivity.