Mineral Separation and Characterization of the Ilmenite Ore Phases: Optimization of the TiO2 Pigment Process

Abstract

The TiO2 production by the sulphate route uses ilmenite as raw material, which is initially milled and dissolved by adding concentrated sulphuric acid (98%). A significant fraction of the original raw material (about 10-15 %) cannot be dissolved in the digestion step. In order to recovery the titanium (rutile form) and other economic minerals during the digestion stay, was carried out a deep characterization of the used raw material in relation to several parameters, such as the elemental composition (major and trace elements), mineralogy, microscopic morphology and physical composition. Therefore, the main goal of this work has been to separate and to analyse the minerals contained in the raw material in order to isolate the potentially dangerous and economics minerals prior to the industrial process. The main conclusion the study was that the raw material is mainly composed of ilmenite and its alteration products (ilmenite unchanged, leached ilmenite, pseudorutile, leached pseudorutile and rutile), produced by weathering of the original ilmenite, and containing small amounts of other minerals (monazite, spinel, quartz and zircon). According to this, a near total isolation of each mineral is very complex, but a high percent of them can be recovery by optimizing the industrial process. In addition, the economical impurities isolated can be commercial. Likewise, this fact could be reduced the potential environmental impact of the TiO2 industries via sulphate by reducing the waste production.