Investigation of the oxidation induration mechanism of Hongge vanadium titanomagnetite pellets with different Al2O3 additions

As part of an ongoing research on the development of a novel clean smelting process for the comprehensive utilization of Hongge vanadium titanomagnetite (HVTM), this study examined in detail the oxidation induration mechanism of WIWI pellets (HVTMP) with different Al(2)O(3 )additions. The results indicated that the addition of Al2O3 significantly lowered the oxidation degree and compressive strength of HVTMP mainly because of the markedly increased porosity and decreased grain size. However, Al2O3 exerted only a marginal effect on the phase composition. With an increase in the amount of Al2O3 added, grain growth was suppressed, the pore size significantly increased, and porous microstructures that formed by the non-homogenous distribution of grains were also obtained. Moreover, Al-rich phases distributed homogeneously in the grains and along the grain boundaries, resulting in the low oxidation induration of HVTMP. A schematic of the oxidation induration mechanism is also presented based on the experimental results, providing a reference for the production of HVTMP and other Al-bearing Fe-Ti oxide minerals. (C) 2019 Elsevier B.V. All rights reserved.