[en] The results of the research of the process of metals extraction from titanomagnetite ore are presented. The experiments were conducted in PVC columns. The most efficient metal recovery is achieved at a hydrofluoric acid concentration of 4 mol/L and ammonium fluoride concentration of 0.42 mol/L. This represent approximately 10% for titanium, iron and vanadium. Selectivity on titanium during percolation of a solution with a hydrofluoric acid concentration of 1 mol/L and ammonium fluoride of 2.5 mol/L is observed. (paper)

[en] The paper contains the results of hydrometallurgical processing of technogenic pyrite raw materials. The method is based on selective extraction of gold and silver from ore by solution, which contains sodium sulfite and sodium sulfate. The most promising results were obtained utilizing solution with sodium sulfite and sodium sulfate concentration of 25 g/L and leaching time – 1 hour. Under these conditions, the extraction of gold was 67%. The use of sodium sulphate and sodium sulfite allows to extract gold and partially silver from refractory sulfide ores. (paper)

[en] Rare-earth permanent Nd-Fe-B magnets are the most promising ones because they have the highest magnetic and operating characteristics. These magnets are produced from alloys having the respective chemical composition principally by the powder metallurgy technology. The paper presents the results of study of the manufacturing process of high-quality permanent magnets by the method of solid-phase alloying of magnetic alloys obtained by means of the out-of-furnace fluoride technique. In the present work, metallic foundry alloys and alloy hydrides of Nd-Fe, Dy-Fe and Tb-Fe systems are considered as alloying additions. (paper)

[en] In this paper we synthesized high entropy oxide system (Sc_0.2Ce_0.2Pr_0.2Gd_0.2Ho_0.2)₂O_3±δ by precipitation of hydroxides from REE nitrates aqueous solutions and annealing the mixture at 800 °C. It is possible to obtain the various forms of simple and complex composition based on the rare earth oxides, including oxides in the form of nanosized powders. The main idea of obtaining HEOS comes from the field of high-entropy alloys. The interconnection between configurational entropy and mixing enthalpy is a key factor for determining phase transformations. The phase composition, structure, and surface morphology of the obtained powders were investigated by scanning electron microscopy and X-ray phase analysis methods. (paper)

[en] In this paper the results of investigation of phase formation and change of concentration of free electrons (Ne) in indium tin oxide system during heat treatment of coprecipitated hydroxides of indium and tin from nitric and hydrochloric solutions and also, for comparison melts of salts nitrates by an alkaline reactant (NH_4OH) are considered.The performed investigation allowed to set the optimal condition of preparation of polycrystalline tin-doped indium oxide with maximal electron concentration. (paper)

[en] The photocatalysis process is widely used for removal of toxic chemical compounds from water and air. Oxides, sulfides of semiconductor materials are used as catalysts in photochemical processes, one of which is titanium dioxide. The manufacturing of an effective catalyst – nanotubes of titanium dioxide and the study of its physicochemical characteristics are considered in this paper. The behavior of titanium dioxide with various structures in the course of removing sulfur-containing organic compounds from diesel oil fractions is investigated. It is found out that titanium dioxide nanotubes (NT) are the most efficient catalysts for the photooxidation. Photocatalytic treatment of diesel fractions allows efficient and simple purification of oil products from unwanted components. (paper)

[en] A thermodynamic investigation of plasmochemical processes taking place in a magnetron during sputtering of the targets consisting of indium and dysprosium ions is performed, which allowed identifying the feasibility of forming under the given conditions certain amounts of the chemical compounds In₂O₃, Dy₂O₃, DyInO₃. In the thermodynamic analysis of the equilibrium compositions during magnetron sputtering of the films, a universal TERRA software program is used.

[en] The article deals with a fundamentally new fluoride technology for obtaining fluoride materials, provides data on the kinetics of the process of fluorination of Fe oxide with fluorine, fluoride and ammonium bifluoride. The physical and chemical properties of obtained fluorides are shown: a study of the elemental composition, grain-size composition using the method of scanning electron microscopy and laser diffraction. (paper)

[en] The features of extraction of rare earth elements (REE) were considered from hydrate-phosphate precipitates of REE of apatite processing by nitric acid technology. The preliminary purification of nitrate solution of REE from impurities of titanium, aluminum, iron, uranium and thorium was suggested to obtain stable solutions not forming precipitates. Washing the extract was recommended with the evaporated reextract that allows to obtain directly on the cascade of REE extraction the concentrated solutions suitable for the separation into groups by the extraction method. Technical decisions were suggested for the separation of REE in groups without the use of salting-out agent. (paper)

[en] The paper deals with the study of processing apatite ores with nitric acid and extraction of the rare earth elements. The rare earth elements can be successfully separated and recovered by extraction from the nitrate- phosphate solution, being an tributyl phosphate as extraction agent. The developed scheme of the processing apatite concentrate provides obtaining rare earth concentrates with high qualitative characteristics. (paper)