Processing of titanomagnetite concentrate with possible production of slags suitable for further recovery of titanium and vanadium

Abstract

This paper describes the results of a study that looked at the processing of Gremyakha-Vyrmes titanomagnetite concentrate resulting in the production of granulated iron and titanium-vanadium slag. The best process for the above concentrate includes direct iron reduction in a rotary hearth furnase. What is peculiar about this process is that vanadium and titanium are both concentrated in the slag that can further be hydrometallurgically processed and vanadium and titanium can be recovered. A protective coal bed should be used in the rotary hearth furnase for this process that would secure against any contact between molten slag and refractory lining. The authors looked at how the concentration of the reducing agent in the burden and the reduction temperature impact the composition of the resultant titanium-vanadium slag during reducing roasting with a protective coal bed. The following composition of slag was obtained when the reduction process was conducted with 16% coke added at 1550 oC, %: 6.2 FeO; 43.9 TiO2; 20.6 Al2O3; 2.3 V2O5; 13.2 SiO2; 7.5 MgO; 4.3 CaO; 0.6 MnO; 0.4 Cr2O3; 0.9 (K, Na)2O. Due to the high concentration of titanium in the slag and due to its presence in the form of anosovite (which can be easily recovered in sulphuric acid) with the general formula n[Al2O3·TiO2]·m[(Mg,Fe)O·2TiO2], the slag can be further processed and vanadium and titanium can be recovered. It is proposed to follow the well-known process scheme for vanadium recovery: i.e. oxidizing roasting – sulphuric acid leaching of calcium vanadates. And it is proposed to use hydrometallurgical processes to recover titanium from the slag. The resulting products can be used to produce both metallic titanium and pigment TiO2.This research was carried out under Governmental Assignment No. 075-00328-21-00.