Effect of Cr2O3 on the break temperature and crystallization behavior of Cr-containing molten titanium slag

Abstract

In the current study, the effect of Cr2O3 on the break temperature and crystallization behavior of Cr-containing molten titanium slag was investigated. The type, composition, and morphology of crystallized phase were analyzed by FactSage, X-ray diffraction (XRD), and scanning electron microscopy (SEM) combined with energy dispersive spectrometry (EDS). It was found that the break temperature (TBr) of Cr-containing molten titanium slag tended to increase with the increase of Cr2O3 content. When the Cr2O3 content was 4 wt%, the TBr was 1470 °C. With the increase of Cr2O3 content, the Ti-containing phase began to appear at the temperature above the TBr. Moreover, the main crystallized phase that existed at the temperature below the TBr transformed from only anosovite to both anosovite and spinel, indicating that Cr2O3 promoted the precipitation of spinel. The rapid increase in viscosity was mainly determined by the precipitation of anosovite in the slag without Cr2O3. When the Cr2O3 content was 2 wt%, the increased precipitation amount of Ti-containing phase caused the abrupt change in viscosity. As the Cr2O3 content further increased to 4 wt%, the precipitation amounts of anosovite and spinel significant increased, which resulted in the sudden increase in viscosity. This study could provide theoretical support for the comprehensive utilization of Cr-containing molten titanium slag and sustainable development of titanium and chromium resources.