Effect of Cr2O3 addition on the oxidation induration mechanism of Hongge vanadium titanomagnetite pellets

As part of a research project to develop a novel clean smelting process for the comprehensive utilization of Hongge vanadium titanomagnetite(HVTM), in this study, the effect of Cr2O3 addition on the oxidation induration mechanism of HVTM pellets(HVTMPs) was investigated in detail. The results showed that the compressive strength of the HVTMPs was greatly weakened by the CrOaddition, mainly because of a substantial increase in the porosity of the HVTMPs. The CrOaddition marginally affected the phase composition but greatly affected the microstructural changes of the HVTMPs. Increased amounts of CrOresulted in a decrease in the uniform distribution of the hematite grains and in an increase in the Fe–Cr solid solutions(FeCrOand FeCrO) embedded in the hematite grains. Moreover, the compact hematite was destroyed by forming a dispersed structure and the hematite recrystallization was hindered during the oxidation induration, which adversely affected the compressive strength. On the basis of these results, a schematic was formulated to describe the oxidation induration mechanism with different amounts of added CrO. This study provides theoretical and technical foundations for the effective production of HVTMPs and a reference for chromium-bearing minerals.