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Objectives. To identify the regularities of electrochemical processing of the heat-resistant GS32-VI alloy in a sulfuric acid electrolyte with a concentration of 100 g/dm3 under the action of a pulsed current in a pulsed mode.Methods. Using the electrochemical technological complex EHK-1012 (developed by IP Tetran) and a non-compensatory method of measuring potential, polarization and depolarization curves with a change in pulse duration and a pause between them were recorded. The current pulses had an amplitude ranging from 0 to 3.5 A (when recording the polarization and depolarization curves), pulse durations ranging from 200 to 1200 ms, and a pause (delay) between pulses ranging from 50 to 500 ms. There were no reverse current pulses.Results. The parameters of the current program that provide the maximum values of the alloy dissolution rate and current output were determined: with a current pulse amplitude of 2 A, a current pulse duration of 500 ms, and a pause duration between pulses of 250 ms, the maximum dissolution rate of the alloy is 0.048 g/h·cm2, while the current output for nickel is 61.6% with an anode area of 10 cm2. The basic technological scheme for processing the heat-resistant GS32-VI alloy, which includes anodic alloy dissolution in a pulsed mode, is proposed.Conclusions. Electrochemical dissolution of GS32-VI alloy under pulsed current action results in an optimal dissolution rate ratio of the alloy components, ensuring the production of a cathode precipitate with a total nickel and cobalt content of 97.5%.

Objectives. To develop physical and chemical bases and methods to obtain rhenium–ruthenium isoproxide Re4-yRuyO6(OPri)10 —a precursor for obtaining a high-temperature alloy—from ruthenium acetylacetonate and rhenium isoproxide acquired by electrochemical methods.Methods. IR spectroscopy (EQUINOX 55 Bruker, Germany), X-ray phase and elemental analyses, energy-dispersive microanalysis (EDMA, SEM JSM5910-LV, analytical system AZTEC), powder X-ray diffraction (diffractometer D8 Advance Bruker, Germany), experimental station XSA beamline at the Kurchatov Synchrotron Radiation Source.Results. The isoproxide complex of rhenium–ruthenium Re4-yRuyO6(OPri)10 was obtained, and its composition and structure were established. Previously conducted quantum chemical calculations on the possibility of replacing rhenium atoms with ruthenium atoms in the isopropylate complex were experimentally proven, and the influence of the electroconductive additive on the composition of the obtained alloy was revealed.Conclusions. Physical and chemical bases and methods for obtaining rhenium–ruthenium isoproxide Re4-yRuyO6(OPri)10 were developed. The possibility of using rhenium–ruthenium Re4-yRuyO6(OPri)10 as a precursor in the production of ultra- and nanodisperse rhenium–ruthenium alloy powders at a record low temperature of 650°C were shown.

Objectives. The present study aims to develop new methods for the synthesis of molybdenum(VI) oxide, which is a precursor for the synthesis of functional materials, as well as to investigate the physicochemical properties of the resulting oxide phases. Methods. The synthesized phases and the products of their thermolysis were studied by differential thermal analysis, IR spectroscopy, X-ray diffraction analysis, and granulometry. Results. Three methods for the synthesis of molybdenum(VI) oxide were developed, and the physicochemical properties of the oxide phases obtained were studied. The first method consisted in the reaction of molybdenum pentachloride with a 6.0–9.5 mol/L ammonia solution, the second one was the reaction of niobium pentachloride with a sulfuric acid solution, and the third method involved the reaction of ammonium molybdate with nitric acid, affording brown molybdenum(V) MoO(OH)3 hydroxide, a bright blue precipitate of molybdenum blue MoO2.75, and white hydrated oxide MoO3·H2O, respectively. Conclusions. A series of thermal and X-ray diffraction analysis demonstrated that in all cases the samples were amorphous phases. Heat treatment at 580 °C of the synthesized phases led to the formation of a rhombic modification of molybdenum trioxide. The lattice parameters and X-ray density were calculated for all thermolysis products. The effect of heat treatment on the particle size of the synthesized samples and their thermolysis products was studied. Particle size analysis demonstrated that particles of different diameters were formed depending on the synthetic method. The smallest particle size (0.3–0.6 µm) was found in molybdenum trioxide, a product of the thermolysis of the sample obtained by the reaction of molybdenum pentachloride with a concentrated ammonium solution.

The article was written for the 150th anniversary of the D.I. Mendeleev’s Periodic Law. The history behind the discovery of dvi-manganese - rhenium by D.I. Mendeleev has been explained. Rhenium as well as its compounds’ fields of application has been indicated. In addition, potential sources of rhenium in Russia have been identified.

Currently, various amino bisphosphonates are widely used in the treatment of many bone diseases. One of the most well-known complex compounds of neridronic acid (6-amino-1-hydroxyhexylidene-1,1- bisphosphonic acid) is sodium neridronate – a bisphosphonate, which is used to treat osteogenesis and Paget's disease. However, there is no data on compounds of neridronic acid with rare earth elements. A new complex of lanthanum with 6-amino-1-hydroxyhexylidene-1,1-bisphosphonic acid (I) was obtained and characterized by various physicochemical methods (chemical analysis, IR spectroscopy, solid-phase 31P NMR spectroscopy, optical microscopy, PCA, DTA). According to the research data the complex I has the composition {La[(H3N-(CH2)5-C(OH)(PO2(OH))2]2(H2O)2}[OH]·H2O and represents the coordination 1D-polymer due to two bridged phosphonic groups with lanthanum atoms in a tetragonal-antiprismatic environment. In a crystal, polymer chains form a 3D-frame porous structure by means of strong hydrogen bonds O─H ··· O and N─H ··· O with endless channels, available to include a variety of inorganic anions or small organic molecules. A study under the microscope showed that the sample is needle crystals (thin rods) of different lengths. The particle size distribution was obtained by laser diffraction, and the average particle size was determined: 50 µm in length and 2.5 µm in thickness.

The article is devoted to the substantiation of the proposed technological scheme of electrochemical processing of rhenium-containing heat-resistant alloy ZhS32-VI of composition (mass %): Re - 4.0; Co - 9.3; W - 8.6; Y - 0.005; Lа - 0.005; Al - 6.0; Cr - 5.0; Tа - 4.0; Nb - 1.6; Mо - 1.1; С - 0.16; B - 0.15; Cе - 0.025, Ni - 60.05 to obtain nickel-containing cathode deposits. The results of studying the composition, surface morphology and granulometric analysis of cathodic precipitates obtained during the electrochemical processing of the spent heat-resistant alloy ZhS32-VI with the use of acid electrolytes are presented. Anodic dissolution of ZhS32-VI was performed in the galvanostatic mode. The effect of the electrolyte composition on the process parameters (current yield, distribution of alloy components between the electrolysis products, particle size distribution of the cathode product), electrochemical processing of this alloy were established. It is shown that depending on the nature of the electrolyte, cathode deposits of different chemical and phase composition can be obtained. They differ in the size and morphology of the surface. It has been established that the value of the cathode precipitate grains obtained in acid electrolytes is almost the same: 99% of the cathode precipitate grains are in the range from 0.04 to 0.60 μm. The main difference is a slight increase in the amount of fine fraction when sulphosalicylic acid is added to the electrolyte. All the cathodic deposits obtained have a dendritic structure, the development of which depends on the nature of the electrolyte, the precipitates obtained with the use of a nitrate electrolyte having the most developed structure and the smallest particle size.

It is interesting in chemical terms and promising in the applied production of new complexes of metals with bisphosphonic ligands with a popular set of consumer properties. To date, little has been studied chemistry of bisphosphonic acid complexes with the basic structure of 1-hydroxymethylene-bisphosphonic acid with a side chain containing 11 carbon atoms and ending with an amino group. The main objective is to obtain new bisphosphonates of s-, p -, d - and f-elements, their characterization by a complex of physical and chemical research methods (NMR and IR spectrometry, RSA, DTA, optical microscopy, laser diffraction) and to identify new applications of bisphosphonic acids and their salts. In the course of the work, complexes of Ag, Pb, Ca, with 1-hydroxymethylene-bisphosphonic acid (H2N(CH2)xC(OH)(H2PO3)2) and its derivatives, the side chain ends with an amino group, its length is 11 carbon atoms. Crystal structures of metal-bisphosphonate complexes with the general formula H2N(CH2)10C(OH)(HPO3)xM (M = Ag, Pb, Ca) were determined. The complexes were characterized by IR spectroscopy and 31P solid-state NMR spectroscopy, RSA. The areas of practical use of the complexes are outlined. It is shown, by the example of wastewater in Kuopio, Finland, that bisphosphonic acids can be used for wastewater treatment of enterprises from heavy metals (M =Pb, Zn, Cd, etc.).

The results of elaborating a method for the synthesis of zirconia and hafnia doped by rare earths (yttrium, erbium and scandium) by using low-hydrated hydroxides of zirconium and hafnium as precursors are reported. The low-hydrated zirconium and hafnium hydroxides were prepared using the heterophase reaction. The physicochemical properties (including sorption properties) of low-hydrated zirconium and hafnium hydroxides ZrxHf1-x(OH)3÷1O0.5÷1.5·0.9÷2.9H2Owere studied. The scheme of thermal decomposition of low-hydrated hydroxides in air was determined. The sorption properties of the low-hydrated hafnium hydroxide are less pronounced owing to the lower amount of sorption centers, in this case, hydroxo and aqua groups. The sequence of stages of thermal decomposition of rare earth acetates was elucidated. Single-phase zirconia and hafnia doped by rare earths (yttrium, erbium and scandium) were obtained. The parameters of the elementary lattice were calculated for each phase. It was established that the stabilization of zirconium dioxide with yttria leads to the formation of interstitial solid solutions based on tetragonal zirconia (in the case of the composition Y2O3×4ZrO2 - cubic modification), with erbium oxide - interstitial solid solutions based on cubic zirconia; with scandium oxide - solid solutions based on tetragonal zirconia. The article presents the results of measuring electrical conductivity.

It was investigated the influence of technological parameters of laser cladding on the thickness of the carbide composite coatings with similar composition and properties of matrix and different types of reinforcing inclusions (spherical tungsten carbides (WC) and recycled carbides). Special attention is paid to physical-mechanical and service properties of the composites such as hardness and resistance to abrasive wear. It is established that the thickness of the carbide composite coatings increases with increasing laser power and flow rate of the carrier gas, and with decreasing speed of the laser and the step of cladding. The study showed that at the addition of 50 wt.% WC matrix has smaller hardness values 540-560 HV, which allows to obtain the structure of the carbide composite coatings without cracks. At the same time, at addition of 80 wt.% WC matrix has higher hardness 670 HV, which does not provide the structure without cracks. Resistance of composites NiCrBSiC-WC to cracking, as well as their wear resistance, increases with increasing content of tungsten carbide. The wear resistance of the coatings received from powder Technicord 655-SL, with a reinforcement by recycled carbide, comparable to that for coatings from spherical tungsten carbide Tekmat WC-125. Coatings NiCrBSiCWC, obtained by laser cladding, are used to increase the service life of the equipment telemetering systems, in particular, it is possible to prevent of abrasion and provide of increasing the service life of the contact pads of the equipment for measurement while drilling.

Tantalum methylate of general formula Ta2(OMe)10 was synthesized by electrochemical synthesis as a precursor for obtaining oxomethylate complexes of tantalum and rhenium. The complex is used to prepare catalysts in reactions of cross-condensation and reductive dehydration of alcohols. The catalysts are based on γ-Al2O3 and TiO2. Ultradisperse and nanosized TiO2 is obtained by the supercritical fluid technology. The sample is characterized by different methods (DTA, XRD, DSC). It is shown that annealing at 340°C allows obtaining anatase modification of TiO2 with a specific urface of 27.3 sq.m/g which can serve as a matrix for drawing active components of catalysts. It is shown that the Ta-Re/Al2O3 catalyst allows transforming ethanol and mixtures of ethanol with glycerin into aliphatic hydrocarbons C3-C11. A technological scheme for obtaining active components of the catalysts for cross-condensation and reductive dehydration of alcohols is suggested.

Our work is focused on a development of physical-chemical backgrounds and methods of controlled synthesis of germanium hydroxide GeO(OH)2, which is a precursor for the synthesis of functional materials based on germanium oxide. The method of controlled synthesis of germanium hydroxide by heterophase interaction ammonia solution with germanium tetraiodide was elaborated. It yields hydroxide with relatively low water content (~ 14 wt. %), which can be easily filtrated. The average germanium dioxide content is as higher as 86 wt.%. Physical-chemical properties of germanium hydroxide and products of thermal decomposition have been investigated by using of chemical and thermal analysis, gravimetric analysis, XRDA, IR-spectroscopy.

This work is devoted to the study of electrochemical dissolution of nickel-rhenium (10% wt.) alloy and nickel-rhenium (20% wt.) alloy. The study was carried out under pulsed current in acidic electrolytes (sulfuric, nitric and hydrochloric acids). It was established that the highest dissolution rate of alloys was achieved at the current pulse amplitude of 1.0-1.5 A, current pulse duration of 500 ms, pause between pulses 50 ms. It is difficult to know exactly which areas meet the electrochemical reaction, but at the expense of depolarization the polarization curve is divided into several sections, each of which correspond to electrochemical reactions. It was shown that both the galvanostatic and potentiostatic modes occur in the selective dissolution of nickel and rhenium. Moreover, the rate of dissolution of nickel and rhenium depends on the acidic electrolyte (sulfuric acid, nitric acid, hydrochloric acid), the ratio of the concentrations of components in the solution, and the content of nickel and rhenium on the surface of the alloy in the nickel-rhenium (10% wt.) and nickel-rhenium (20% wt.) alloys. It was revealed that the highest dissolution rate for the nickel-rhenium (10% wt.) alloy (10.76 g/A·h) is achieved by dissolving in nitric acid, which is less than the dissolution rate of the nickelrhenium (20% wt.) alloy (12.08 g/A·h) in nitric acid. In contrast, in sulfuric and hydrochloric acids the dissolution rate of nickel-rhenium (20% wt.) alloy is much higher compared to the nickel-rhenium (10% wt.) alloy.

Niobium and tantalum methylates with common formula M2(OMe)10 , where M - Nb,Ta, have been synthesized as precursors by electrochemical synthesis for obtaining niobium and tantalum oxides. Ultradispersed and nanosized oxides TT (δ)-Nb2O5 and T (γ)-Ta2O5 were obtained by supercritical fluid technology. The samples are characterized by different methods (chemical analysis, DTA-DTG, XRD, IR-spectroscopy, grain size analysis). It is shown that under the experimental conditions amorphous particles of niobium and tantalum pentoxides are formed, which react to form the crystalline state at temperatures of 600°C and 750°C respectively. Crystallization temperature of T(γ)-Ta2O5 obtained by SAS-technology significantly lower than the crystallization temperature of the same tantalum pentoxide obtained by heterophasic method (900°C). The particle size of the annealed tantalum pentoxide is in the range of nanosized materials, particle size of the annealed niobium pentoxide qualifies them as ultradispersed.

The work presents the results of investigations of physico-chemical properties of low hydrated hydroxides of niobium and tantalum – precursors for obtaining niobium and tantalum pentoxides with ordered phase and granulometric compositions

New technology to obtain Re, Ni, Co hydroxides, simple and complex oxides, fine and nanosized powders of metals and alloys has been developed. Mono- and heterometallic nickel, rhenium and cobalt alkoxides with adjustable metal content were used as precursors to produce final powders.

The article deals with the history of the production of rare earth elements (REE) in the Soviet Union, the changes that have occurred in connection with the collapse of the Union, the role of JSC "Solikamsk Magnesium Works" (JSC "SMW") in the rare metal industry today. It is shown that the introduction of chlorine processing method of loparite concentrate allowed to include in the work cycle about a quarter of the chlorine volume produced by the electrolysis of MgCl2 and laid the foundation for the economic sustainability of the enterprise. The prospects of the development of REE production in our country are scheduled.

The process of rhenium anodic dissolution in methanol in the presence of lithium chloride was investigated. The unique construction of an electrochemical sell, firmware and the experimental technique for the investigation of anodic dissolution of rhenium and other d-elements in the water-free alcohols ROH (R = Me, Et, i-Pr, etc.), enabling to control and maintain constant potential (or current, if required), as well as to control in situ the concentration of the metal against the process duration were developed and introduced into the research process. A possible mechanism, by which rhenium derivatives are formed, was suggested.

The processes of complexing have been investigated for anodic dissolution of rhenium in a mixture of methanol and acetylacetone. A scheme of thermal decomposition of the obtained products has been suggested, and the temperature dependence of the phase composition of thermal decomposition products has been determined.

First rhenium oxobutoxoderivatives with n-BuOH and i-BuOH have been obtained by electrochemical method. The decomposition rhenium complex with n-BuOH at 412°С in oxidizing atmosphere results in obtaining oxides of Re(VI) and Re(IV) in the condensed phase.

The novel compounds Li6MNb4O14 (M = Zn, Mg) have been synthesized and characterized in the Li2O-MO-Nb2O5 (M = Zn, Mg) system. The synthesized phases were investigated by XRD, DTA and the chemical analysis. Specific conductivity and energy of activation of each compounds and the sample that doping by titanium oxide has been found. Comparison of absorption IR-spectra of investigated compounds and of samples Li6ZnNb4O14 having isotope on lithium and zinc has been compared.

The article presents new generation of the electrochemical equipment realizing technologies with controllable potential. The basic differences and advantages of electrochemical complex before the existing equipment are given. Examples of application electrochemical complex in technology of rare and platinum metals are given.

The overview discloses the results of development of synthetic methods and investigation of physico-chemical properties (structure, thermal, thermodynamic, electrophysical and catalytic characteristics) of a wide range of materials based on less-common elements. These involve materials prospective for application in computer memory, superionic conductors of NASICON-type phases, substrates for HTSC-films of various composition. The results of directed search and chemical design of precursors (soft chemistry routs) for fabrication of ferroelectrics, alloys and mixtures based on refractory metals of V-VII Groups in nano-dispersed state, solid solutions based on corresponding oxides and complex oxide phases are concerned

Work concerns studying process of electrochemical dissolution of the nickel besieged from waste solutions by an electrochemical way. The influence of key parameters of technological process - potential, temperature, pH, speed of a channel of electrolyte, structure of electrolyte on process of dissolution of nickel are determined.

The paper considers the Saint-John-Bloch model and proves that this model is applicable for describing phase equilibrium in binary systems formed by pentachlorides of d-elements of groups V, Vl, Vll of the periodic system and lanthanide chlorides. The dependence of the possibility of forming solid solutions in LnCl3-Ln'Cl3 on the atomic number of a lanthanide was found.