Hydrometallurgical criteria for TiO2 leaching from Rosetta ilmenite by hydrochloric acid

This work is concerned with the determination of the leaching characteristics of TiO2 from ilmenite by hydrochloric acid. This can be considered as an alternative to selective iron dissolution and insolubilization of TiO2 in the form of synthetic rutile. The relevant criteria for TiO2 leaching in hydrochloric acid are studied, including the acid concentration and solid/liquid ratio - which control the acid/ilmenite molar ratio - as well as the effect of reduction. The data reveals that the optimum conditions involve working with 12 M acid with a solid/liquid ratio of 1/20 at 80 degrees C for 2.5 h, using ore ground to -200 mesh size. Under similar reducing conditions using 0.1 kg metallic iron powder/kg ilmenite, there is a marked decrease in the optimum solid/liquid ratio to 1/8 and in the leaching time to 1.5 h. (C) 2007 Elsevier B.V. All rights reserved.