Open Access Conference Proceedings

This study examines the efficacy of hydrogen in reducing iron compounds found in dust emissions during the electric arc furnace (EAF) steelmaking processes at "Uzbeksteel" JSC (Uzbekistan). EAF dust is a fine secondary material composed of 30 to 60 percent iron oxides (Fe2O3, Fe3O4, FeO). The accumulation of approximately 60,000 tons of this dust underscores the importance of developing sustainable recycling methods. The current investigation involved hydrogen reduction experiments conducted at 1100°C for 30 minutes, utilizing a continuous low-pressure hydrogen flow. Thermodynamic analysis using Ellingham diagrams indicated that iron oxides are selectively reduced between 650 and 750°C, where the standard free energy (ΔG) values are negative. However, the reduction of ZnO is only favorable at temperatures above 900°C. The reduction process is characterized by gas-solid interactions, the diffusion of hydrogen through porous particles, and the sequential transition of Fe2O3 to Fe3O4 to FeO to Fe. The experimental results demonstrate the metallization of iron and the partial volatilization of zinc, which facilitates the process. Furthermore, hydrogen promotes CO2 free processing, enhancing environmental performance. Hydrogen has been shown to enable processing without carbon dioxide emissions, making it environmentally superior to carbon-based reductants.

Keywords: electric arc furnace dust, hydrogen reduction, iron oxides, zinc oxide, JSC “Uzbeksteel”, sustainable metallurgy, technogenic waste

© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.