Eulerian Multiphase Modeling of Iron Oxide (FeO) Reduction in HIsarna-Type Slag by H2-Ar Lance Injection

The reduction of molten Iron (II) oxide (FeO) by gaseous hydrogen has emerged as a research focus due to its favourable reduction kinetics, with the aim of enabling low-carbon steel production, driven by the European Green Deal [1, 2].
This work builds upon the experimental study of Htet et al. [1], in which FeO-bearing synthetic slag, representative of that used in the HIsarna process, was investigated under H2-containing gas injection via an alumina lance. The HIsarna process, based on smelting reduction, is regarded as one of the most promising technologies within the ULCOS program, aiming to reduce CO₂ emissions by approximately 20% through process integration [2].
An Eulerian multiphase multi-species model was developed to simulate FeO reduction by an injected H2-Ar gas mixture in molten HIsarna slag at 1550 °C, consisting of CaO-SiO2-Al2O3-MgO-FeO. The system comprises three phases: a liquid slag phase in which FeO serves as the reactive species; a gaseous phase containing H2, Ar, and H2O as the gaseous reduction product; and a liquid metal phase representing the reduction product, Fe. Transient simulations were performed to resolve details of flow structures, including phase velocities, species distributions, and reaction zones, considering the highly turbulent flow induced by gas lance injection and bubble-induced turbulence [3]. Model predictions were validated against experimental data.

[1] T.T. Htet, Z. Yan, B.S. Kumar, J. Hage, K. Meijer, Z. Li, Ironmaking & Steelmaking 50 (2023) 1590-1600.
[2] D. Spreitzer, J. Schenk, Steel Research international 90 (2019) 19000108.
[3] E. Karimi-Sibaki, A. Vakhrushev, M. Wu, J. Bohacek, A. Kharicha, Chemical Engineering Research and Design 208 (2024) 731–739.