Chlorination of reduced ilmenite concentrates and synthetic rutile

Chlorination of reduced ilmenites of different grades (primary, secondary and HYTI 70) and synthetic rutile was investigated at 235 °C. The main phases of primary and secondary ilmenites were Fe2Ti3O9 and FeTiO3; HYTI 70 contained TiO2; synthetic rutile consisted of titania with titanium suboxides and trace amount of iron. Iron oxides were reduced to metallic iron. Titanium oxides were reduced to titanium oxycarbide or oxycarbonitride; reduced samples contained a small amount of titanium suboxides. In chlorination of reduced ilmenite concentrates and synthetic rutile, titanium oxycarbide or oxycarbonitride, metallic iron, and Ti2O3 were chlorinated. The degree of chlorination of both iron and titanium oxycarbide/oxycarbonitride was 95–98%; chlorination of iron was faster than that of titanium oxycarbonitride. The removal of iron by leaching increased the chlorination rate of titanium oxycarbide/oxycarbonitride; it was close to completion in 35 min.

► Ilmenite concentrates were reduced to titanium oxycarbide or oxycarbonitride and metallic iron.
► Titanium oxycarbide and oxycarbonitride in reduced ilmenites were chlorinated at 235 °C.
► Iron was chlorinated at low temperature chlorination conditions.
► Iron was removed by leaching reduced ilmenites by aeration with NH4Cl catalyst.
► After iron removal, chlorination of titanium oxycarbide and oxycarbonitride became faster.