Preparation and purification of titanium carbide via vacuum carbothermic reduction of ilmenite

An economical route has been developed to prepare high purity titanium carbide from Panzhihua ilmenite, which has high contents of Mg and Si. In this paper, high purity (>99 wt%) TiC particle was prepared by vacuum carbothermal reduction followed with acid leaching and alkali leaching processes. The current process has a lower reaction temperature, and a shorter reaction time, meanwhile the used raw materials are much cheaper than the industrial method of preparing TiC which used TiO2 and C as the raw materials. Effects of atmosphere, reduction temperature and carbon ratio were studied and the purification mechanisms of elements Mg, Mn, Ca, Si, Al were put forward. Mg and Mn could be separated in gaseous state during vacuum carbothermal reduction. Al was reduced to Al4C3 after reduction and then was removed in acid leaching process. Meanwhile, CaO was also removed in the acid leaching process. SiO2 was reduced to the dissolved silicon in liquid iron firstly, then formed amorphous silicon after acid leaching, and finally was removed in alkali leaching process. The as-prepared TiC powder had a narrow particle size distribution within 1-20 μm and Dv50 was 5.29 μm.