Influence and Mechanism of CaO on the Oxidation Induration of Hongge Vanadium Titanomagnetite Pellets

The oxidation induration process of Hongge vanadium titanomagnetite pellets (HVTMP) with different amounts of CaO was investigated. This research forms part of an ongoing study on a novel and clean smelting process for the comprehensive utilization of Hongge vanadium titanomagnetite. The results revealed that the compressive strength of HVTMP could be enhanced by adding only 1% CaO because of the formation of fine grains and homogenous microstructures. However, a further increase in CaO decreased the compressive strength. Excessive amounts of CaO decreased the grain size but increased the porosity, impeding the oxidation induration process of HVTMP. An increase in CaO slightly influenced the phase compositions but largely reduced their peak intensities. An innovative index, namely induration degree, was proposed to directly estimate the induration behavior of HVTMP. A schematic diagram was presented to clearly describe the induration mechanism of HVTMP with different amounts of added CaO.