Effect of Basicity on the Hydrogen‐Rich Reduction Behavior of Vanadium‐Titanium Magnetite Pellets: Reduction Mechanism within Hydrogen‐Rich Blast Furnace

Hydrogen‐rich blast furnace smelting technology, as a low‐carbon metallurgical technology, has gradually gained extensive attention from academia and the steel industry. In this work, the reduction behavior of vanadium‐titanium magnetite (VTM) pellets with different basicity in a hydrogen‐rich blast furnace atmosphere is investigated for the first time, and its reduction mechanism is elaborated. It is shown that the presence of CaO changed the composition of the slag phase and negatively affected the compressive strength of the post‐reduced VTM pellets. The increase in temperature intensified the molecular motion and diffusion processes of the reducing gases, which increased the gas diffusion rate and the phase boundary reaction rate and promoted the reduction reaction. The micro‐morphological evolution of the VTM pellets during the reduction process is as follows: dense blocky structure → dense spherical structure → loose spongy structure → fibrous and semi‐fibrous structure → coralloid structure. As the basicity increased, the structural integrity of the reduced VTM pellet is damaged, and the reduction degree increased. This work can provide theoretical support and technical basis for hydrogen‐rich blast furnace smelting VTM.