Thermodynamics analysis for the zinc ferrite reduction by hydrogen

Abstract

Electric arc furnace (EAF) dust, a by-product from steelmaking, contains recoverable metals such as zinc and iron that are found almost entirely as zinc ferrite (ZnFe 2O 4/, magnetite (Fe 3O 4/ and zinc oxide (ZnO). The dust has been classified as a hazardous waste due to the relatively high content of lead, cadmium and chromium. In 2010, around 7 million tons of EAF dust were generated worldwide. In this research, the equilibrium module of Outokumpu HSC Chemistry®6.1 was utilized to calculate the standard free energy changes and the composition of the products resulting from the reduction of zinc ferrite by hydrogen over the temperature range from 673 to 1873 K (400 to 1600°C) at atmospheric pressure (1 atm). The experimental studies have been conducted on the utilization of hydrogen as a reducing agent for zinc ferrite in EAF dust. The comparison of the thermodynamic investigation models with experimental results was carried out in the temperature range of 773 to 1073 K (500 to 800°C) is also presented in the research. Copyright © 2012 De Gruyter.