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 Al4O4C, Al4C3, Al2OC, Al2O and Al. Experiment results show that the carbothermic reduction products of alumina are Al4O4C and Al4C3, and neither Al2OC, Al2O or Al was found. During the carbothermic reduction process, the reaction rate of Al2O3 and carbon decreases gradually with increasing time. Meanwhile, lower system pressure or higher temperature is beneficial to the carbothermic reduction of alumina process. Al4O4C is firstly formed in the carbothermic reaction, and then Al4C3 is formed in lower system pressure or at higher temperature.