Preparation of Titanium Oxycarbide from Ilmenite (FeTiO3) Concentrate Through Thermal Reduction and Magnetic Separation Processes

Ilmenite concentrate has emerged as the key titanium raw material for exploitation and utilization, playing a crucial role in the preparation of metallic titanium and titanium dioxide. However, the presence of impurities such as Fe, Ca, and Mg in ilmenite concentrate severely restricts its economic utilization and environmentally friendly applications. In our previous research, a novel process was proposed to prepare TiCl4 from high-Ca- and Mg-containing ilmenite through carbothermal reduction and boiling chlorination. Nevertheless, the employment of graphite as a reducing agent and hydrochloric acid for metallic iron separation led to elevated production costs. The aim of this study was to explore an alternative and more cost-effective method. Petroleum-derived coke was used as the reducing agent to investigate the feasibility of producing titanium oxycarbide from ilmenite concentrate via carbothermal reduction and magnetic separation. The results showed that petroleum-derived coke is capable of reducing ilmenite concentrate to coral-shaped TiCxOy under high-temperature conditions. However, an approximate 100 °C increment in temperature is required to reach an equivalent reduction efficiency compared with graphite. The X-ray diffraction (XRD) analysis results of the reduced products reveal that complete reduction of ilmenite concentrate by petroleum-derived coke can only be achieved when the reduction process is conducted at 1600 °C for 3 h or at 1500 °C for 5 h. The reduced product obtained at 1600 °C, characterized by a substantial presence of dense Ti2O3, exhibits a significantly coarser particle size after 30 minutes of ball milling in contrast to the reduced product obtained at 1200 °C, which is rich in M3O5 anosovite. Magnetic separation results showed that the reduction product at 1200 °C could not have metallic iron removed by magnetic separation at 1.2 T, while the reduction product at 1600 °C could yield a non-magnetic charge rich in Ti2O3 and TiCxOy with an iron content as low as 2 ± 0.03 wt.%, which fully meets the requirements for producing TiCl4 by boiling chlorination. Overall, these research results offer a new approach for the low-cost production of TiCl4 from ilmenite concentrate with high levels of Ca and Mg impurities through boiling chlorination.