Kinetic and Mechanism Study of the Reduction of WO 2 to W by CO or CO-CO 2 Mixed Gas

In the work, the reaction kinetic and mechanism of the reduction of WO 2 to W by CO or CO-CO 2 mixed gas were investigated in the range of 1351–1430 K. Various technologies such as XRD, FE-SEM, TG, thermodynamic calculation, and model fitting methods were adopted to analyze the experimental data. The results showed that the reduction of WO 2 to W was a one-step reaction process without any intermediate products generated. The higher the temperature was, the faster the reduction rate. The reduction processes of WO 2 to W by CO or CO-CO 2 mixed gas was controlled by the interfacial chemical reactions with the activation energies extracted being 113 kJ/mol and 90 kJ/mol, respectively. Combining the phase transition and morphology evolution characterizations, a possible reaction mechanism for the reduction of WO 2 to W was proposed.