Carbothermic reduction of alumina with carbon in vacuum

Carbothermic reduction alumina in vacuum was conducted, and the products were analysed by means of XRD and gas chromatography. Thermodynamic analysis shows that in vacuum the initial carbothermic reduction reaction temperature reduces compared with that under normal pressure, and the preferential order of products is Al 4 O 4 C, Al 4 C 3 , Al 2 OC, Al 2 O and Al. Experiment results show that the carbothermic reduction products of alumina are Al 4 O 4 C and Al 4 C 3 , and neither Al 2 OC, Al 2 O or Al was found. During the carbothermic reduction process, the reaction rate of Al 2 O 3 and carbon decreases gradually with increasing time. Meanwhile, lower system pressure or higher temperature is beneficial to the carbothermic reduction of alumina process. Al 4 O 4 C is firstly formed in the carbothermic reaction, and then Al 4 C 3 is formed in lower system pressure or at higher temperature.