Thermodynamic Analysis of Carbothermic Reduction of Electric Arc Furnace Dust

Electric arc furnace (EAF) dust is a kind of secondary resource which contains multiple metallic elements, including Fe, Mn and Cr. Pyrometallurgical processes for recovering metal elements from EAF dust have been investigated for many years although they are suffered from high energy consumption due to the spinel-structured components of EAF dust. In this study, the thermodynamic analysis of carbothermic reduction of EAF dust was performed. The main components of EAF dust were magnetite (Fe3O4), hausmannite (Mn3O4) and chromate spinel (FeCr2O4). The gangue minerals were mainly composed of magnesium silicates. The thermodynamic analysis indicated that magnetite and hausmannite can be reduced to metallic iron and MnO, respectively. Meanwhile, the chromate spinel will be reduced to chromium oxide and then to form CaCr2O4. The results also demonstrated that the gangue components can promote the separation of Fe and Cr, agreeing well with the experimental results.</p