The Investigation on Enrichment of TiO2 from Ti-Bearing Slag

Abstract

Titanium-bearing slag in this study was produced by subjecting titanium-bearing sea sand iron mineral to direct reduction smelting process. The enrichment and growth of titanium-rich phase in the titanium slag were investigated. The phases in slag were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. The results showed that Ti-rich phase had a pseudobrookite structure, and it was close to diffractogram of anosovite phase (M3O5 (M = Mg, Al, Ti)), in which the theoretical content of TiO2 is 73.2%. Line-scanning analysis was used to clarify the elements distribution trend in titanium slag. The results showed that Ti element was enriched in the anosovite phase, and Si and Ca assembled in the matrix phase. Mg and Fe elements were distributed in larger proportion in the anosovite phase, while the Al element was more enriched in the matrix phase. The experimental results showed that low cooling rate was in favor of titanium precipitate in anosovite phase. Moreover, the growth of anosovite crystal was characterized by kinetic model. These results provided further insights into the separation of anosovite from gangue by mineral processing.