Thermodynamic behavior of calcified carbothermal reduction of zinc ferrite

By combining thermodynamic calculations and experimental study, the thermodynamic behavior of calcified carbothermal reduction of zinc ferrite in zinc-containing electric arc furnace dust was analyzed, and the effect of reduction temperature and the molar ratio of carbon to oxygen on the calcified carbothermal reduction behavior of zinc ferrite were discussed. The results showed that compared with traditional carbothermal reduction, calcified carbothermal reduction of ZnFe₂O₄ can produce ZnO at a lower temperature, and some elemental Zn can be directly obtained from ZnFe₂O₄ at 1 100 K. When the temperature was higher than 1 221 K, both elemental Zn reduced from ZnFe₂O₄ and Zn reduced from ZnO were volatilized in the form of zinc vapor, and the volatilization was enhanced with the increase of carbon ratio and temperature. Furthermore, calcified carbothermic reduction not only lowered the temperature at which ZnFe₂O₄ disappeared but also reduced the temperature and carbon consumption required for the reduction to produce metallic iron and zinc. CaO can reconstruct the phase of the material, significantly reducing the temperature points at which the reaction of zinc ferrite with iron oxide produced ZnO, Zn, and Fe, thus allowing ZnFe₂O₄ to react completely earlier. At a temperature of 1 270 K and a molar ratio of carbon to oxygen (n（C）/n（O）) of 0.7, optimal reduction and separation of zinc and iron in ZnFe₂O₄ were achieved, with Zn volatilizing in vapor form and Fe being reduced to metallic form.