Leaching kinetics of electric arc furnace dust in nitric acid solutions

Abstract

Electric arc furnace dust contains mainly ZnO, ZnFe2O4, and iron oxides. In this study, chemical composition of ZnO, ZnFe2O4, and Fe(2)O(3)and leaching kinetics of ZnO, ZnFe2O4, and Fe(2)O(3)in HNO(3)solutions were investigated. It was seen that the dissolution of ZnO is very fast, therefore the leaching kinetics of ZnO cannot be determined. Kinetic parameters and model equations were derived for the leaching of ZnFe(2)O(4)and Fe(2)O(3.)Leaching kinetics of ZnFe(2)O(4)was explained by the pseudohomogeneous reaction model. Activation energy and order of HNO(3)concentration were found to be as 37.5 kJ mol(-1)and 0.37, respectively. The model equation was derived asXZnFe2O4=1-exp[-62.83C00.37exp(-37522/8.314T)t]. It was determined that experimental data for the leaching kinetics of Fe(2)O(3)best fit with the shrinking core model (SCM). Activation energy and order of HNO(3)concentration were found to be as 51.5 kJ mol(-1)and 0.67, respectively The model equation was derived using SCM asXFe2O3={1-[1-1181.45Co0.67exp(-51545/515458.314T8.314T)t]3}(.)