Solid state reduction of a natural ilmenite

An ilmenite concentrate was reduced with graphite under argon gas between 1250 degrees C and 1350 degrees C by using a thermogravimetric analysis (TGA) system. Specimens were reacted for various periods of time during which the mass loss values were recorded. Samples representing different reduction stages were examined by optical microscopy, image analyzer, X-ray diffraction and SEM (EDAX) techniques. Reduction of Fe3+ to Fe2+, Fe2+ to Fe and Ti4+ to Ti3+ took place within 50% reduction during which a secondary oxide phase was formed and replaced the natural ilmenite. Reduction of Ti3+ to Ti2+ took place after 50% reduction which altered the composition of the secondary oxide phase by decreasing its oxygen content. Reduction of Ti2+ took place while the oxygen deficient TiO1-x phase formed. Formation of any titanium carbide or oxycarbide phases depended on the completion of the reduction which was not possible at the specified temperatures. (c) 2005 Elsevier Ltd. All rights reserved.