Carbothermic Reduction of Zinc Ferrite by Microwave Heating

摘要

The kinetics of carbothermic reduction of ZnFe_2O_4 in the temperature range 823-1223 K, was investigated in a microwave reactor. The mechanism of formation of ZnO and Fe_3O_4/FeO by decomposition of ZnFe_2O_4 was explained using the equilibrium calculations and thermodynamics analysis using HSC chemistry software 6.0. In addition the effect of parameters such as the decomposition temperature, C/ZnFe_2O_4 ratio, particle size and microwave power were assessed on the decomposition kinetics. Zn recovery as high as 98.83 could be achieved at a decomposition temperature of 1023 K, C/ZnFe_2O_4 ratio of 1:3, particle size of +74-61 μm and microwave power of 1200 W. The kinetics of decomposition was found to be carbon gasification reaction controlled, with the activation energy of 39.21 kJ/mol.