Extraction of aluminum from alumina by disproportionation process of AlCl in vacuum
(1. Faculty of Science, Kunming University of Science and Technology, Kunming 650500, China;
2. National Engineering Laboratory of Vacuum Metallurgy, Faculty of Metallurgy and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China)
2. National Engineering Laboratory of Vacuum Metallurgy, Faculty of Metallurgy and Energy Engineering,
Kunming University of Science and Technology, Kunming 650093, China)
Abstract: The extraction conditions of aluminum by the disproportionation process of AlCl in vacuum were investigated using alumina and graphite as raw materials, including reaction temperature, pre-reaction and condenser structure. The results show that the extent of the reaction between alumina and carbon increases with increasing reaction temperature at 1643-1843 K; however, the extraction rate of aluminum increases firstly, and reaches the highest at 1743 K, and then decreases with rise in reaction temperature. The pre-reaction of alumina and carbon increases the extraction rate of aluminum. The impurities C, Al4C3 and Al2O3 in the aluminum product are reduced with reducing the contact surface of the aluminum with CO and with decreasing the condensation temperature, depending on the structure of the condenser.
Key words: aluminum; AlCl; alumina; extraction; vacuum; disproportionation