Non-Isothermal Kinetic Analysis of Magnesium Salt Oxidation Roasting Process of Vanadium-Titanium Magnetite Concentrate

Abstract

To enhance the recovery rate of vanadium from vanadium-titanium magnetite concentrate, we investigated a series of oxidation roasting reactions involving vanadium-titanium magnetite concentrate and magnesium oxide using non-isothermal kinetics. We employed four different model-free methods to calculate the apparent activation energy of the reactions over a temperature range of 396.2 to 836.6℃. Among these, the KAS method showed the best fitting accuracy, yielding an activation energy of 225.97 kJ/mol. This method was utilized to derive a stage reaction model and describe the kinetic mechanism. Our analysis confirmed that the A2 and A8 nucleation models were the dominant mechanisms throughout the entire reaction stage. Based on the derived kinetic mechanism, we propose strategies for enhancing reactivity through material pretreatment in the early reaction stage and employing a gradient temperature roasting strategy to increase the reaction temperature.