Preparation of titania from llmenite by selective H2S sulfidization

Experiments on preferential sulfidization of ilmenite in a static bed by hydrogen sulfide gas with a flow rate of about 20 cu cm per min were conducted at 800°, 900°, 1000°, and 1100°C for different periods. Sulfidization (conversion of about 95 pct of the iron to its sulfide) at 1000°C for 5 hr or at 1100°C for 4 hr was considered quite suitable. The sulfidized samples were leached with boiling dilute hydrochloric acid and the influence of the concentration, amount of the acid, and the duration of leaching was studied. Leaching was most effective by employing 20 pct excess 2 N boiling hydrochloric acid for 1/2 hr. By this treatment, about 95 pct of the iron in ilmenite could be removed and a residue containing about 91 pct TiO₂ has been obtained. X-ray analysis revealed that TiO₂ in the residue has rutile structure. The merits of the process for commercial utilization have been mentioned briefly.