Gas-Based Direct Reduction of Hongge Vanadium Titanomagnetite-Oxidized Pellet and Melting Separation of the Reduced Pellet

Abstract

The recovery rates of vanadium, titanium, and chromium are much low in the current process of the vanadium titanomagnetite in Hongge region, China. In order to utilize Hongge vanadium titanomagnetite (HVTM) effectively, a novel clean process is proposed in this study, in which HVTM-oxidized pellets are reduced initially in shaft furnace and then melting separated. The influences of reduction temperature and ratio of φ(H2) and φ(CO) on the reduction process and melting morphology of the reduced pellets are investigated. It is found that the rate and degree of reduction are improved with the increase of temperature and ratio of φ(H2) and φ(CO). The appropriate temperature and ratio of φ(H2) and φ(CO) are 1050 °C and 2.5, respectively. The phase transformations of the valuable elements during the reduction process can be described as follows: Fe2O3 → Fe3O4 → FeO → Fe; Fe9TiO15 → Fe2.75Ti0.25O4 → Fe2TiO4 → FeTiO3 → TiO2; (Fe0.6Cr0.4)2O4, Fe0.7Cr1.3O3 → FeCr2O4; (Cr0.15V0.85)2O3 → Fe2VO4. The recovery rates of iron, vanadium, chromium, and TiO2 are 98.7, 88.27, 91.38, and 92.52%, respectively. The separated iron is a clean raw material for steelmaking; moreover, the titanium-rich slag can be used for further process to recover titanium. This study aims to provide theoretical and technical bases for the comprehensive utilization of HVTM and increase the recovery rates of valuable elements.