There are provided processes for purifying aluminum ions. Such processes comprise precipitating the aluminum ions under the form of Al(OH)3 at a first pH range; converting Al(OH)3 into AlCl3 by reacting Al(OH)3 with HCl and precipitating said AlCl3; and heating the AlCl3 under conditions effective for converting AlCl3 into Al2O3 and optionally recovering gaseous HCl so-produced. The processes can also comprise converting alumina into aluminum.