Consolidation and reduction behaviour of pellets with sea sand vanadium titanomagnetite: a microscopic interpretation of macroscopic properties

The compressive strength of pellets is of great significance for the evaluation of pellets quality indexes. In this paper, the chemical composition, mineral phase composition and microstructure of pellets were analyzed by ICPAES, XRD, OM and SEM-EDS through oxidation roasting and gas-based reduction experiments. The effect mechanism of thermal regulation on the compressive strength and reduction performance of pellets was explained by the micro-indicators such as porosity, Vickers hardness and morphological structure of pellets. The results showed that with the increase of the roasting temperature and the extension of the roasting time, the internal porosity of the oxidized pellets was reduced, while the compressive strength of the pellets was continuously improved, and the roasting temperature had a greater influence on the compressive strength. However, the increase in porosity of the reduced pellets weakened the intergranular bonding between the particles, which led to a reduction in compressive strength.