Metallurgical Properties of Vanadium Titanomagnetite Sinter in the Cohesive Zone of H2-rich Oxygen Blast Furnace

Vanadium titanomagnetite is a mineral resource with high economic value and strategic significance. Its main smelting process, the blast furnace-basic oxygen furnace process, generates high CO₂ emissions. The H₂-rich oxygen blast furnace process has been demonstrated to be an effective technique to reduce CO₂ emissions in blast furnace operations. In this study, the H₂-rich oxygen blast furnace condition was simulated combined with the softening–melting apparatus and the mass spectrometer, and the effects of H₂ content (0–30 vol pct) on the cohesive zone metallurgical properties of vanadium titanomagnetite sinter in H₂-CO gas mixtures were discussed from softening–melting behavior, permeability, TiC formation, slag foaming characteristics, gas utilization rates, and the softening–melting mechanism. The results indicate that with increasing H₂ content in gas mixtures, the reduction degree of the burden improved, accompanied by an increase in H₂ utilization. The softening interval shifted to higher temperatures because of the increased metallic iron content, which impeded further deformation of the burden. The melting starting temperature increased due to the liquid slag volume decreased. The decrease of [C] content in the hot metal leads to an increase in the dripping temperature. The permeability of the feed bed has improved greatly. Furthermore, the N₂-free atmosphere avoided TiN formation, while CaTiO₃ prevented the carbonization of TiO₂ to TiC, leading to no foaming slag being observed.