KINETICS OF THE OXIDATION AND REDUCTION OF SYNTHETIC ILMENITE

The kinetics of the oxidation and reduction of synthetic ilmenite was studied thermogravimetrically in the light of kinetic theory for heter ogeneous noncatalytic reactions. It was found that the oxidation and r eduction proceeded topochemically and their kinetic parameters were de termined according to the unreacted core shrinking model. The mineral composition of the partially oxidized and/or reduced ilmenite was exam ined by means of characteristic X-ray analysis, the results of which s howed that there were two phases in the oxidized ilmenite which separa ted each other. One of them was rich in titanium and the other was ric h in iron. There were two phases too separating completely in the redu ced ilmenite, one of which was the metallic phase consisting of almost pure iron and the other was an oxide phase mainly composed of titaniu m dioxides. The composition of the titanium-rich phase in the oxidized ilmenite was between the composition of Fe2O3.TiO2 and that of Fe2O3. 3TiO2.