Chlorination of Reduced Ilmenite Concentrates and Synthetic Rutile

摘要

Chlorination of carbothermally 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 Fe_2Ti_3O_9 and FeTiO_3;HYTI 70 contained TiO_2;synthetic rutile consisted of titania with titanium suboxides and a small amount of iron. Iron oxides were reduced to metallic iron. Titanium oxides were reduced in argon to titanium oxycarbide or in nitrogen to 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 Ti_2O_3 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 oxycarbide/oxy-carbonitride. The removal of iron by leaching increased the chlorination rate of titanium oxycarbide/oxycarbonitride; it was close to completion at 235°C in 30 min.