Which of the following statement(s) is(are) correct for the extractive metallurgy of aluminium ?
(A) Red bauxite contains the impurities of iron oxides SiO2 and TiO2.
(B) Red bauxite is purified by Hall’s and Serpeck’s process
(C) Hall-Heroult process is used for the electrolytic reduction of molten alumina dissolved in molten cryolite.
(D) In electrolytic reduction of alumina fluorine gas is liberated at anode as by product.