Isolation of Elements

(A) Electrochemical extraction of Aluminum from bauxite done below 2500∘C
(B) 2‌Na[Al(OH)4]‌aq. ‌+2CO2(g)→Al2O3⋅3H2O(s)↓+2NaHCO3(‌ aq. ‌)
The sodium aluminate present in solution is neutralised by passing CO2 gas and hydrated Al2O3 is precipitated.
(C) Al2O3(s)+2NaOH(aq.)+3H2O(l)→2‌Na[Al(OH)4]aq.
Concentration of bauxite is carried out by heating the powdered ore with hot concentrated solution of NaOH
(D) In metallurgy of aluminum, Al2O3 is mixed with Na3AlF6