Work

Preparation and smelting behavior of a vanadium–titanium magnetite all-pellet burden for blast furnace ironmaking

Year: 2026

Type: article

Abstract: All-pellet blast furnace ironmaking can reduce sinter consumption and support energy savings and emission reductions. Using self-fluxing pellets of a single formulation can simplify burden composition while meeting slag formation requirements. This study combined independent isothermal reduction tests and softening drippinger tests under load with phase and microstructural characterization. These experiments simulated the evolution of self-fluxing vanadium-titanium magnetite pellets in stages corresponding to different blast furnace regions. Under conditions representative of the lumpy zone, iron oxides underwent stepwise reduction, and an Fe-bearing perovskite-type calcium titanate appeared. During the soft melting stage, residual iron oxides coexisted with metallic iron, while Ti became enriched in perovskite. During slag-metal separation, metallic iron separated from the Ti-bearing slag. The cooled slag consisted mainly of perovskite, silicates, and spinel. Compared with a reference burden comprising 65% sinter and 35% pellets, the self-fluxing pellet burden exhibited narrower softening and melting intervals. The permeability index S and cohesive layer thickness decreased by 13.1% and 9.0%, respectively. Compared with the R = 0.2 pellet burden, T s was 50 °C lower, and the overall softening–dripping interval narrowed from 298 to 263 °C. These findings indicate the potential to improve permeability in the blast furnace soft melting zone and provide experimental support for optimizing all-pellet burdens.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2026.10.280