Geological setting and mineral composition of (apatite)-nepheline-titanite ore from the Khibiny massif enable selective mining of titanite ore, and its processing with sulfuric-acid method, without preliminary concentration in flotation cells. In this process flow diagram, titanite losses are reduced by an order of magnitude in comparison with a conventional flotation technology. Further, dissolution of titanite in concentrated sulfuric acid produces titanyl sulfate, which, in turn, is a precursor for titanosilicate synthesis. In particular, synthetic analogues of the ivanyukite group minerals, SIV, was synthesized with hydrothermal method from the composition based on titanyl-sulfate, and assayed as a selective cation-exchanger for Cs and Sr.

In the last years the interest in new synthetic and natural titanosilicates has increased. Due to the tunable pore diameter and other distinct characteristics, these materials can be utilized for commercially important separations of gas mixtures of similar size molecules, catalysts and removal of radioactive elements from nuclear waste. However, from the point of view of industrial synthesis, scale-up complicated technology and high cost of the agents are limiting factors, hence it is of interest to research new materials to replace expensive pure titanium precursors and stimulate studies to develop an efficient technology. The results of synthesis of the new nanoporous titanosilicates using cost efficient ammonium oxysulphotitanate are presented. By carefully selecting the titanium sources and synthesis parameters, it is possible to obtain titanosilicate Na₂K(Ti₄(OH)(SiO₄)₃ analogue of the mineral pharmacosiderite.

The metastable structure state of the anatase phase of titanium dioxide has been shown to be a favorable basis for a targeted influence on it with the aim of producing new oxide phases consisting of nanoparticles and, accordingly, having a new combination of properties. Mechanical activation and subsequent annealing of the activated powders result in a sequence of phase transformations (anatase–brookite–rutile), thereby ensuring structural ordering of titanium dioxide. Transformations of the titanium oxide phases have been studied in detail by X-ray diffraction. We have evaluated the crystallite (coherent scattering domain) size and internal strain (ε) from diffraction line broadening by profile fitting with the pseudo-Voigt function. The average particle size was 20 nm after mechanical activation, whereas heat treatment increased it by almost a factor of 2. Similar results have been obtained for internal strain. The pore system of the particles is formed by mesopores. The hysteresis loop observed in nitrogen sorption–desorption isotherms suggests that the titanium dioxide particles have platelike morphology. The results obtained in this study have been used to develop innovative technology of a special grade of titanium dioxide for the preparation of thermally stable glues with dielectric properties and high tensile and shear strength.

In this paper, a universal technology is proposed for processing low-titanium mineral raw material—apatite-nepheline ore waste, including its treatment with sulfuric or hydrochloric acid in a two-stage mode with a sequential increase in the concentration. This technique allowed us to remove nepheline and apatite in the first stage and achieve a titanium mineral content of TiO₂ of more than 30%; in the second stage, we were able to convert the titanium into its precursors—titanyl sulfate monohydrate TiOSO₄·H₂O and a hybrid rutile-silica composition. The key stage in the sorbent synthesis is the reaction of the precursor with a phosphoric acid solution. The preferred sequence of operations begins with the mechanical activation of the precursor, causing morphological changes in it, and subsequent treatment with phosphoric acid at different concentrations under atmospheric conditions and in an autoclave, accompanied by phase transformations. Conditions for the chemical reactions which regulated the composition and structure of the final product and, accordingly, its sorption activity were found. With the help of XFA, the phase compositions of the sorbents were identified, including the individual crystalline phase α-TiP obtained from TS or the crystalline phase αTi(HPO₄)₂∙H₂O, which is in an amorphous silica matrix obtained from a rutile–silica composition.

An original method based on the use of technogenic waste from the processing of mineral-layered materials, in particular phlogopite for obtaining highly efficient functional compositions of the “mica-TiO₂”, has been developed. The composition core is a nanosized mica flake coated with mesoporous titanium dioxide of an anatase or rutile structure. Energy-saving and environmentally friendly technological methods are based on the splitting of the mica followed by heterogeneous electrohydrolysis of a mixture of titanium (IV) sulfate solution and flake particles. No destruction of the mica surface, which provided the obtained uniform coatings, has been observed. Such coatings are used in photocatalysis processes and possess a self-cleaning capability. Core–shell compositions are more economically attractive compared with titanium dioxide, in particular TiO₂ grade P25 (Degusse). The core of the transparent flake and the shell of the rutile titanium dioxide endows the final product with a pearlescent optical effect. This type of material is widely used in the manufacturing of paints and varnishes, printing inks, cosmetics, etc. The use of technogenic waste could significantly reduce the cost of the final product, which would ensure its widespread use in various industries.

Lithium compounds are of high interest to many industries. The presence of undesirable impurities in Li precursors leads to uncontrolled change in the functional properties of final compounds. Therefore, the development of reliable methods for lithium salt purification is considered a key factor for their application in various industries. This work focuses on the application of a titanium phosphate ion exchanger (Li-TiOP) toward Cu²⁺, Co²⁺, Mn²⁺, Ni²⁺, and Cr³⁺ ions in the purification of a saturated LiNO₃ solution. The sorption kinetics of the selected ions, considering external and internal mass transfer, as well as chemical interaction, were deeply studied. The kinetic study showed that the values of intraparticle diffusion rate and effective diffusion coefficients for the studied ions decreased in the following order: Cr(III) ˃ Cu(II) Mn(II) ˃ Co(II) ˃ Ni(II). For all the selected ions, chemical interaction was described with a pseudo-second-order reaction model. The sorption kinetics were controlled by the size of the solvated metal ion, its effective charge, the electronic structure of the adsorbed ion, and the interaction with the functional groups of the sorbent. Due to fast kinetics, the high degree of removal of trace quantities of the impurities this material gives it consideration as a promising sorbent for the deep purification of lithium salts.