Kinetics Study on Oxidization Process of Cemented Carbide Scrap

Air oxidation is an important method to achieve clean recycling of cemented carbide scrap. However, the current production practice has the problem of long reaction time and low efficiency. Among them, the most important influencing factor is the continuous accumulation of the product layer hindering the oxidation reaction, how to solve this problem is the focus of our research. In this research, the effect of different air flow rates, alloy compositions, and temperature conditions on the oxidation rate of WC–Co alloys was investigated, and a kinetic model was fitted. The feasibility of using a shrinking core model for cubes was demonstrated. The results indicate that the air flow rate and alloy composition have a minor effect on oxidation, while temperature significantly impacts the reaction rate. Furthermore, the good fit of the model confirms that the process aligns with the shrinking core model. As the reaction progresses, the loose oxidation products WO₃ and CoWO₄ accumulate, leading to a shift in the control step from a chemical reaction to internal diffusion.