The reduction of titania-ferrous ore (ironsand) containing 57.2 wt% of iron and 7-8 wt% 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.
Titano-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.