Thermodynamics, kinetics and mechanism analysis of aluminothermic reduction for preparing Al-Zr alloy

In this study, we investigated the thermodynamics and kinetics of the aluminothermic reduction of ZrO 2 . The results of thermal analysis and isothermal heat treatment showed that the aluminothermic reduction of ZrO 2 was an exothermic reaction that occurred at . 958.8°C. The aluminothermic reduction process does not produce metal Zr, but when the stoichiometric number of Al:ZrO 2 was 13:3, Al 3 Zr and Al 2 O 3 can be obtained by the reaction. The activation energy of the reaction was 1589.89 kJ/mol, and the reaction order was 1.90. The aluminothermic reduction process and mechanism of ZrO 2 in the presence of potassium cryolite as the molten salt medium was also studied. The results showed that ZrO 2 dissolved in potassium cryolite molten salt and participated in the reduction reaction in the form of Zr–O–F complex ions, while the by–product Al 2 O 3 also dissolved in potassium cryolite to further promote the formation of the Al–Zr alloy.