Kinetics of Solid-State Reduction of Ilmenite Ore

Abstract

Abstract Solid-state reduction of ilmenite ore by carbon under nitrogen was studied at temperatures up to 1200°C. The rate of reduction was followed by determination of oxygen loss and by chemical analysis for metallic and ferrous iron. The reduction process proceeds through different stages with formation of structures intermediate between iron and reduced forms of titanium oxides. The results show that the reduction of titanium dioxide to its lower oxides takes place in parallel with the reduction of iron oxides. The oxygen deficiency in reduced titanium dioxide increases with increases in reduction temperature and time. Iron oxides are not reduced completely owing to the presence of some residual ferrous oxide combined in a structure which resists reduction. The mechanism and kinetics of the reduction process are discussed. The reduction data under isothermal conditions are consistent with a mixed model with phase-boundary reaction and diffusion processes controlling the reduction rate up to about 80% ...