Melting Behavior of Hydrogen-Reduced Vanadium-Bearing Titanomagnetite Ironsand Pellets in a Laboratory-Scale Electrode Smelter

Abstract Hydrogen direct-reduced iron (H 2 -DRI) production is an emerging low-emission route for ironmaking. Combining this process with electric smelting furnace (ESF) technology presents a viable pathway for low-to-medium-grade iron ores, as the ESF offers flexibility in handling variable feed compositions and slag volumes. In this preliminary work, H 2 -DRI pellets made from vanadium-bearing titanomagnetite (VTM) ironsand from New Zealand were smelted in a laboratory-scale electrode smelter. The carburization degree, element partitioning, and vanadium behavior were examined. Effective separation of carburized hot metal and high-titania slag was demonstrated for H 2 -DRI feed with reduction degrees ranging from 85 to 93% and varying charged C/Fe ratios. H 2 -DRI feed with low reduction degree of 85% yielded a final metal carbon content of 3.6 wt.% C. This was primarily driven by the higher charged C/Fe ratio, however, the effect of residual iron oxides in driving carbon uptake is yet to be investigated. Additionally, while the majority of vanadium was detected in the metal phase, some was also observed in a (Ti,V)C phase that formed at metal-slag interfaces. The formation of (Ti,V)C constitutes a competing mechanism that limits recovery of vanadium in the metal phase. These preliminary findings indicate that H 2 -DRI pellets prepared from VTM ironsand can be melted in an ESF environment, though further investigation is required to fully understand the mechanisms involved in this complex system. Graphical Abstract