Effect of CaO on zinc migration mechanism and kinetics during zinc ferrite reduction

Effects of CaO, reduction time and reduction temperature on the Zn migration mechanism and kinetic model were studied. Results show that CaO improves the volatilization rate of Zn by promoting the precipitation and enrichment of the intermediate product ZnO on the surface of the mixture of Fe and CaO. The reduction steps of ZnFe2O4 with CaO are ZnFe2O4 -> Ca2Fe2O5 -> FeO -> Fe. The volatilization model of the reduction of ZnFe2O4 was changed from a first-order chemical reaction model (without CaO) to a three-dimensional diffusion model (with CaO), and the apparent activation energy was reduced from 313.9 to 91.77 kJ/mol, providing favorable conditions for the efficient reduction and volatilization of zinc.

Automated summary

The effects of CaO, reduction time, and reduction temperature on the migration mechanism and kinetic model of Zn were investigated. Results showed that CaO enhanced the volatilization rate of Zn by promoting the precipitation and enrichment of ZnO on the surface of the Fe-CaO mixture. The reduction steps of ZnFe2O4 with CaO were ZnFe2O4 -> Ca2Fe2O5 -> FeO -> Fe. The volatilization model of ZnFe2O4 reduction shifted from a first-order chemical reaction model to a three-dimensional diffusion model, with a decrease in apparent activation energy from 313.9 to 91.77 kJ/mol, providing favorable conditions for efficient zinc reduction and volatilization.