REFINING METHOD OF ALUMINUM

摘要

PURPOSE:To remove impurities from a crude Al alloy and to improve the content of Al in the crude alloy by liquefying and reducing an alumina-contg. material together with an eutectic melting agent in a blast furnace and reducing the resultant crude Al alloy in the presence of H2 under adequate conditions. CONSTITUTION:A mixture 7 composed of the alumina-contg. material such as bauxite and the eutetic melting agent such as CaO is charged from a hopper 6 into the blast furnace 1 provided with a packet bed 2 of coke, etc. O2 is then blown from an oxygen blast pipe 3 into the furnace to form a combustion region 4 and a reduction region 5. The liquefied eutectic CaO-Al2O3 matter is thereby formed and is reduced to form the crude Al-Fe-Si alloy. The crude Al alloy is reduced at 100-900 deg.C in the presence of 1-500atm H2. The impurities in the above-mentioned crude alloy are thereby removed and the unreacted Al2O3 in the slag is reduced, by which the content of Al is improved. The refined Al alloy is subjected to vacuum distillation and the refined Al is obtd.