KINETICS OF SOLID-STATE REDUCTION OF ILMENITE ORE

Solid-state reduction of ilmenite ore by carbon under nitrogen was stu died at temperatures up to 1200-degrees-C. The rate of reduction was f ollowed by determination of oxygen loss and by chemical analysis for m etallic and ferrous iron. The reduction process proceeds through diffe rent 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 titaniu m dioxide increases with increases in reduction temperature and time. Iron oxides are not reduced completely owing to the presence of some r esidual ferrous oxide combined in a structure which resists reduction. The mechanism and kinetics of the reduction process are discussed. Th e reduction data under isothermal conditions are consistent with a mix ed model with phase-boundary reaction and diffusion processes controll ing the reduction rate up to about 80% reduction.