Reduction Process of Pellet Containing High Chromic Vanadium-Titanium Magnetite in Cohesive Zone

In the present study, the reduction process of pellet containing high chromic vanadium–titanium magnetite in cohesive zone has been investigated. To elucidate the reduction process including the softening and melting properties, structure changes and migration processes of valuable components (Fe, V, Ti, and Cr) in pellet containing high chromic vanadium–titanium magnetite in cohesive zone, the experiment was carried out at different temperatures and the pellet samples were analyzed by the methods of XRD, SEM, and chemical analysis. The results of reduction process show that the temperature range of cohesive zone of pellet is from 1087.9 to 1338.3 °C and the maximum differential pressure of the burden is 15 859 Pa at the temperature of 1291 °C. The reduction process of pellet was gradually conducted from outside to inside, which could form a layer of iron shell on the outer surface of the pellet. A lot of wustite could be generated in the core of pellet when the reduction temperature exceeded 1100 °C. The migration process of iron is Fe2O3 → Fe3O4 → FeO → Fe, while the generated FeO could react with SiO2 forming 2FeO · SiO2. The reduction process of titanium is Fe2O3 · 3TiO2 → Fe5TiO8 → Fe2TiO4 → FeTiO3 → Ti(O0.19C0.53N0.32) → Ti(C,N) → [Ti] and MgO · TiO2 → Ti(C,N) → [Ti]. The migration process of vanadium is V2O3 → VN, VC → [V] and the chromium oxide was reduced as follows: (Fe0.6Cr0.4)2O3 → FeCr2O4 → [Cr].