Pre-oxidation of New Zealand ironsand – Where does the titanium go?

The interplay between iron- and titanium oxides has been studied, for a better understanding of how different amounts of titanium affects iron ore, for relevance in downstream ironmaking processes. The oxidation of NZ ironsand as well as synthetic titanomagnetite (TTM) of three different compositions has been studied in air up to 1320°C. In-situ monitoring of mass gain and thermal response during oxidation (TGA-DSC), as well as ex-situ analysis of crystals phases (powder XRD) and microstructure (SEM) of samples after quenching from select oxidation temperature at deliberate time intervals. Crystal phases in the samples were mapped spatially using SEM- EBSD, and chemical composition using (SEM-EDS). This has enabled a detailed evaluation of the relationship between the growth of specific crystals and their relative chemical compositions.