Carbothermal reduction of ilmenite concentrates and synthetic rutile in different gas atmospheres
Carbothermal reduction of ilmenite concentrates and synthetic rutile was studied in isothermal experiments in hydrogen, argon and helium in a tube reactor. Concentrations of CO, CO2 and CH4 in the off gas were measured online using an infrared gas analyser. The reaction products were analysed by X-ray diffraction. Pseudorutile and ilmenite were the main phases in ilmenite concentrates. Reduction of ilmenite concentrates and synthetic rutile in hydrogen was significantly faster than that in inert atmosphere. The effect of gas atmosphere became stronger for lower grade ilmenite containing more iron oxides. The conversion rate of titania to titanium oxycarbide in hydrogen decreased with increasing grade of ilmenite concentrate. In inert gas, the reduction rates of secondary ilmenite and HYTI70 were close to that of primary ilmenite. Reduction of synthetic rutile was faster in comparison with ilmenite concentrates.