Joint processing of perovskite and ilmenite concentrates. Part 1. Chemical-mineralogical (material) characteristics of perovskite and ilmenite concentrates

Abstract

Russia has an impressive titanium mineral resource while the contribution into the global production of titanium concentrates is quite insignificant. The current annual demand of Russian enterprises for titanium raw materials is 40 times higher than its production. To improve and launch the processing of domestic titanium raw materials characterized by low quality and complex polymineral composition, new process solutions are required. These solutions should aim at the full extraction of TiO2 and related valuable components from the ore deposits whose development is planned or already started (for example, Afrikanda – perovskite-titanomagnetite deposit located on the Kola Peninsula). This report presents the results of studying the chemical and mineral compositions of perovskite and ilmenite concentrates with the purpose to assess the possibility of their joint processing using carbothermic reduction melting. Emission spectrometry, X-ray diffraction, electron microscopy, and X-ray spectral microanalysis were applied in these studies. It was found that the basis of the ilmenite gravity concentrate sample is modified ilmenite represented by leucoxenization products – pseudorutile and rutile, with their total content in the concentrate to be about 80 wt. %. Composition of other minerals (alumochromite, chromite, magnetite) includes titanium in the form of impurities – 2 – 3 wt. %. In the perovskite flotation concentrate sample titanium is contained in perovskite and titanite making up the bulk of the ore minerals of the concentrate. As for rare and rare-earth elements contained in the ilmenite sample – monazite having up to 33 wt. % Ce, and zircon were found. Perovskite sample contains rare-earth elements (REE concentration in wt. %) in loparite-(Ce) (22.8), aluminocerite-(Ce) (46.2), anсylite-(Ce) (51.3), torite (22.3), as well as in the main mineral – perovskite (2.8). With the exception of perovskite and loparite-(Ce), other REE-containing minerals are rare, and their share in total does not exceed 1 wt. %