Removal of the vanadium impurities from crude TiCl4 with high content of vanadium using a mixture of Al power and white mineral oil

The purification of crude titanium tetrachloride (TiCl4) with vanadium impurities (mainly as VOCl3 and VCl4) was investigated by treatment with a mixture of Al powder and white mineral oil (WMO). L9 orthogonal array and analysis of variance (ANOVA) were applied to determine the optimal condition and most significant factors. In comparison with the conventional purification processes by adding WMO or Al powder alone, with WMO or Al powder as purification agent, the present process showed obvious advantages in saving the reaction time and improving the purification efficiency. Scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) were further used to measure the residue after purification. The results showed that VOCl3 was converted to insoluble VOCl2 by reduction of TiCl3 through the reaction of Al powder with TiCl4 and active carbon produced from the pyrolytic cracking of WMO.