Reduction of titania-ferrous ore by carbon monoxide

The reduction of titania-ferrous ore (ironsand) containing 57.2wt% of iron and 7-8wt% of TiO2 was investigated in non-isothermal and isothermal reduction experiments using CO-CO2-Ar gas mixtures in a laboratory fixed bed reactor. Samples in the course of reduction were characterised using XRD, EPMA and SEM. Two types of particles were identified in ironsand: 1) homogeneous particles of titano-magnetite with cubic spinel structure (a major type); and 2) non-homogeneous particles, characterised by lamellar structure of rhombohedral titano-hematite, exsoluted from the titano-magnetite. T itano-magnetite, which is a magnetite-ulvospinel solid solution (Fe3O3)(1-x)(Fe2TiO4)(x') with x=0.27+/-0.02, was reduced to metallic iron and titanium sub-oxides. Titanium had a strong effect on the mechanism and rate of reduction of iron oxide in ironsand.