Purification of Rutile Ore by HCl and HF Leaching

In this study, purification of rutile ore by leaching using 2–12 mol/L HCl and 2–12 wt% HF was investigated based on the thermodynamic analysis of the main involved reactions and experimental characterizations mainly using chemical titration, X-ray diffraction (XRD), and scanning electron microscopy (SEMScattering electron microscopy (SEM)). It was shown that compared with traditional HCl leachingLeaching, HF leachingLeaching could extract more impurities because of easier reactions between HF and impurity oxides, in spite of minor loss of TiO2TiO caused by its reaction with the acid. The purificationPurification performance of both acids increased initially and then decreased with increasing acid concentration. When the ore was leached using HCl with concentration of 6 mol/L at 60 °C for 4 h, the TiO2TiO content was enhanced from 95.39 to 97.31 wt% with the highest impurity removal percentage of 41.65%. For HF leachingLeaching, the proper acid concentration was 6 wt%. Under the same conditions as those in HCl leachingLeaching, the TiO2TiO content in the ore could be elevated to 98.77 wt% with the impurity removal percentage of 73.32%.