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One of the most complicated tasks in spent nuclear fuel reprocessing is the separation of rare earth elements (REE) from transplutonium elements (TPE). This is due to the proximity of the extraction and sorption properties of REE and TPE. One of the most efficient and industrially tested methods of separating REE from TPE is extraction with tributyl phosphate in the presence of complexones. The difficulty in developing an effective technology for REE separation from TPE is that these elements are capable to form many complex compounds both in the aqueous phase and in the extractant. Moreover, almost any change in the extraction system (pH, type of salting-out agent, concentration of the target component, etc .) leads to a change of the dominant reactions and significantly changes the distribution coefficients. These features of the behaviour of the elements under consideration have led to the fact that the effective development of the technology of REE and TPE separation is practically impossible without designing a multifactor computer model of the process The formal system of equations of chemical thermodynamics (CTD) is a convenient element for presenting and processing data during modeling such systems. Relying on this postulate, we have developed a new specialized numerical method for calculating the composition of equilibrium chemical systems through the iterative solution of the formal system of CTD equations. The developed program based on this numerical method was used to optimize the technology of extraction separation of REE and americium.

Sodium-ion batteries (SIB) are the nearest alternative to lithium ion batteries (LIB) for stationary energy storage devices. However, at the moment, SIB are inferior to LIB in energy density due to the lower efficiency of sodium-containing electrode materials, which encourages the emergence of new developments in this field. The review provides examples of some promising sodium-containing cathode materials obtained by mechanochemically assisted solid-state synthesis. It is shown that this approach is an energy- and eco-efficient method for the synthesis of single-phase, nanostructured cathode materials. An increase in their electron conductivity is achieved through surface modification with an electrically conductive carbon at the stage of synthesis. A complex of modern physicochemical methods was used to study their crystal and local structure, morphology, and electrochemical properties during cycling in both Na and Li electrochemical cells. The specific energy was compared with that of the known lithium-containing cathode materials.

Results of fundamental research carried out at the Institute of Solid State Chemistry and Mechanochemistry SB RAS on the development of technologies for extracting lithium from both mining and hydromineral raw materials are presented. In the 50s of the last century, the Institute was the first in Russia to develop a technology for processing spodumene concentrate to obtain lithium compounds. In order to develop a technology for extracting lithium from hydromineral raw materials, the processes of lithium chloride intercalation into the crystal structure of aluminium hydroxide have been studied. It has been shown that the intercalation process is accelerated when disordered Al(OH)₃ is used. In order to create a technology for extracting lithium from brines, double compounds of aluminium and lithium were obtained using amorphous aluminium hydroxide. These compounds possess the ability to partially deintercalate lithium chloride when treated with water and to restore the composition again in lithium-containing salt media. This reversible process is the basis for the development of a selective sorbent for the sorption of lithium chloride from highly mineralized multicomponent brines.

The effect of electron-beam treatment with doses up to 450 kGy on the properties of triaminotrinitrobenzene (TATB) was studied. A linear dependence of the number of paramagnetic centres on the treatment dose and their stability upon heating have been revealed. It is shown that electron beam treatment leads to an increase in the interlayer distance in the crystal structure of TATB, causes a significant increase in its volatility and a decrease in the temperature of the onset of intense decomposition by 20 ^oС.

The matrix material based on NdAlO₃ was obtained by means of self-propagating high-temperature synthesis of the NiAl intermetallic compound by diluting the mixture of Ni and Al components with Nd₂O₃-Al₂O₃ oxides. Nd₂O₃ was used as a simulator of actinoids in high-level radioactive wastes. The influence of the batch parameters of the initial components on the synthesis process was studied and optimal conditions for preparation were determined: the density of the system should not exceed 5.2 g/cm³ and the content of the included radioactive waste simulator should not exceed 40 mass %. The composition of the final product and its properties were studied using a complex of physicochemical methods. According to the data of XRD analysis, the maximum possible formation of the NdAlO₃ phase is observed for the sample containing 40 mass % Nd₂O₃-Al₂O₃, with the density of 5.15 g/cm³, obtained by pressing at a pressure of 30 MPa. The studies of the material characteristics have shown the simulator maximum leaching rate 2.66 · 10^-9 g/(cm² · day) . The limits of matrix characteristics variations were determined through the simulation of the storage of matrix material in geological formations by irradiation with neutron fluxes in a research reactor. For instance, a decrease in hydrolytic stability was 10-13 % and a decrease in compressive strength was 7 % on average. The general regularities of structural changes in the matrix material under the influence of ionizing radiation fluxes were considered. Insignificant destruction of the crystal structure was observed due to the appearance of various defects. The limiting value of the changes in sample volume was 4.3 %. However, the characteristics of the samples meet all the requirements to materials intended for the immobilization of radioactive waste.

Results of the works on the development of the technology of phloroglucinol production are presented. Phloroglucinol is a known multipurpose organic reactant that has gained wide and diverse applications, in particular as the starting compound for the synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene. A review of the known methods of phloroglucinol synthesis is presented. The method which is most promising from the standpoint of commercialization is studied. The method is based on the reduction of nitroaromatic precursors - 2,4,6-trinitrobenzoic acid and 1,3,5-trinitrobenzene - to 1,3,5-triaminobenzene, followed by its hydrolysis. Alternate approaches to the synthesis of 2,4,6-trinitrobenzoic acid from 2,4,6-trinitrotoluene are proposed. The catalytic hydrogenation of 2,4,6-trinitrobenzoic acid and 1,3,5-trinitrobenzene over palladium-containing catalysts was studied in detail, and the effect of various process parameters on the yield of the reaction product 1,3,5-triaminobenzene was determined. Hydrolysis of triaminobenzene to form phloroglucinol is considered.

The oils of the Central part of the Siberian platform are very diverse in their physicochemical properties. The studied oils were divided into four groups relying on the data on the group composition of hydrocarbons and the content of resin-asphaltene substances. Physicochemical properties of oils were determined in each group. The features of the individual composition of saturated hydrocarbons ( n -alkanes, isoprenoids, 12- and 13-monomethylalkanes, cyclopentanes, cyclohexanes, terpanes, and steranes) and aromatic hydrocarbons (alkylbenzenes, naphthalenes, fluorenes, biphenyls, phenanthrenes) were determined by means of gas-liquid chromatography and gas chromatography/mass spectrometry. The regularities of changes in the composition and physicochemical properties during the transition from group I oils characterized by rather low content of resinous and asphaltene components to the high-resinous oils of the IV group were determined. These changes are mainly related to the differences in the conditions under which the oil source rocks were accumulated and to the extent of their thermal maturity.

The results of the studies into the synthesis of ether derivatives of nornornene series, their properties and application areas are analyzed. The main directions of the use of ether derivatives of norbornene, as well as the ways and prospects of their further application, are shown. A broad application of norbornene ethers as additives to synthetic oil and fuel compositions, plasticizers, modifying agents and hardeners, as components in the perfumery industry, antimicrobial and antifungal preparations, catalysts and cocatalysts are highlighted. It is demonstrated that adding these esters to diesel fuel leads to a significant improvement in its thermal oxidation stability, a decrease in its pour point and an increase in the flash point. The ethers of norbornene series are considered as new functionally substituted monomers for the synthesis of modified norbornene-containing polymers and co-polymers. It has been established that fluorine-substituted norbornene-containing ethers are applied as a matrix material for photoresists used in microlithography.

This work deals with the problem of utilization of iron-containing waste and its processing into a pigment with improved colouring properties. Steel scrap has been used as an alternative raw material for the electrochemical synthesis of pigments based on iron oxide for use in the production of construction materials. Investigation of the samples by means of X-ray diffraction analysis and scanning electron microscopy showed that the conditions of electrochemical synthesis have no effect on the phase composition and morphology of the samples. It was established that iron oxide powders after thermal treatment at 750 ^oC are composed of hematite α-Fe₂O₃, are characterized by pure and bright colour, and by the absence of impurities. To determine the colouring properties of the pigment, the resulting iron oxide was mixed with clay rock in various proportions and heated to high temperatures.

A brief review of the results of studies in the area of obtaining linear and polycyclic derivatives of dicarboxylic acids is presented. Attention to the indicated compounds is due to the broad and diverse areas of their application in technology, in agrochemical and pharmaceutical industries, as biologically active agents, fragrances, additives to lubricating oils, plasticizers, stabilizing and modifying agents for polymer materials, etc. Biologically active compounds - the derivatives of bisamides of dicarboxylic acids possessing antibacterial, antiviral, anticonvulsant, antitumour, analgesic, fungicide properties are used for prophylactics and treatment of cardiovascular, viral and oncological diseases. The high thermal and thermal-oxidative stability of the adamantine derivatives based on dicarboxylic acids is also of great interest. These compounds, due to their properties caused by the presence of the framework fragment, are used for the synthesis of high-molecular compounds, in the production of fuel and lubricants or as additives to them. The rational use of more available, cheap raw material and the possibilities to use it for obtaining the derivatives of dicarboxylic acids in higher yields define the relevance of the studies aimed at the search for new promising methods to synthesize these compounds.