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A review of systematic studies of unbranched radical-chain reactions by the example of pyrolysis of hydrocarbons and dichloroethane with the participation of heterogeneous catalysts is presented. It is shown that the determining role in catalytic pyrolysis is played not by the concentration of surface or gas-phase active centres but by the total concentration of free radicals per unit reaction volume, which determines the heterogeneous-homogeneous nature of the process. Four types of surface impact on the process have been identified: inhibitory, neutral, accelerating the heterogeneous or homogeneous components of the process. A phenomenological model of these reactions and experimental evidence of its validity are proposed. For catalysts that accelerate the homogeneous component, the effect of “ignition” of the catalyst activity is detected, and its nature is explained. The concept of catalysis spheres is introduced - the areas above the catalyst with an increased concentration of radicals. Its dimensions and conditions of existence are determined. Experimental criteria for the emergence of the sphere are determined. Techniques of purposeful selection and synthesis of catalysts, selection of methods of technological arrangement of radical-chain heterogeneous-homogeneous processes are shown.

A method for producing biocomposite fertilizers with increased water resistance, based on the sequential impregnation of supports from pine bark with the solutions of urea and potassium dihydrophosphate is proposed. The structure of supports prepared from pine bark and fertilizers based on them was studied by means of scanning electron microscopy. The ability of biocomposite fertilizers based on pine bark supports to provide slow outwashing of mineral components with water for a long time was established. The treatment of fertilizers with water at room temperature for 15 days results in the removal of nitrogen, phosphorus and potassium by not more than 34.4, 74.3 and 58.4 wt. %, respectively (of the initial content), which evidences in favour of the prolonged action of biocomposite fertilizers based on pine bark. It is shown that the use of support obtained through extraction treatment of pine bark with organic solvents allows making a fertilizer with higher stability against nitrogen removal with water in comparison with the fertilizer based on the support prepared by treating pine bark with 1 % NaOH solution. Vegetation experiments on germination of Megion oat seeds revealed the same growth-promoting effect of biocomposite fertilizers based on supports obtained using different methods: the length of sprouts and roots increased by a factor of 1.5 in comparison with the reference experiment (water). The studies demonstrated the high potential of the developed fertilizers as an alternative to traditional water-soluble fertilizers and provided evidence of the possibility to obtain them using either original pine bark or wastes from its extraction processing.

Electron microscopy and X-ray fluorescence spectroscopy were used to study the effect of the cooling parameters of the melt obtained by reductive melting of the Chuktukon rare metal ore on the composition of the silicate and metal phases formed. The conditions for ore reduction and melt cooling are established, ensuring the predominant transition of iron, manganese, niobium and titanium into the metallic phase, and rare earth elements concentrating in the silicate phase, which is important for subsequent stages of ore processing. With relatively rapid cooling of the melt, the slag and metal parts of the system are homogeneous. In contrast, with a slow decrease in temperature, the formation of several phases with different chemical compositions is observed in both parts of the system.

The production of many important carbon materials is currently based on the use of aromatic fractions of coal tar - a minor by-product in the production of metallurgical coke for the needs of ferrous metallurgy. Innovations to reduce the consumption of expensive metallurgical coke in blast furnace smelting and the priority development of the coke-free methods of steel production lead to a reduction in the output of coke-chemical products, which destabilizes the prospects for the production of important carbon materials, including those necessary for ferrous and non-ferrous metallurgy. The relevance of creating alternative methods for obtaining aromatic feedstock is substantiated. The potential of low-temperature coal processing by its thermosolvolysis with the production of concentrates of aromatic substances is shown. The possibility of their use as the raw material in the production of carbon anodes for the process of aluminum electrolysis is demonstrated.

To develop recommendations for the optimal consumption of food items considering the features of the Far North regions and the regional specificity of mineral composition, the content of 25 chemical elements was analyzed in the food items of local origin and those transported to the territory of the Magadan Region. It is determined that a portion of beef from cows grown in Magadan contains substantially higher amounts of calcium, sodium and phosphorus than beef samples brought from other regions. Locally produced beef liver contains higher concentrations of iron, iodine, manganese, and zinc. Locally produced pork contains significantly higher amounts of copper ( p = 0.01) and iron ( p = 0.1) in comparison with pork transported from other regions. Evaluation of microelement concentrations in vegetables in comparison with imported samples shows that local carrots contain higher selenium concentration, local cucumbers - higher potassium, copper, and manganese, beetroot is richer in selenium and zinc, with its portion being able to meet fully the daily demand for manganese. In all the analyzed vegetable samples imported from China, nickel content is higher than in local products. In addition, Chinese carrots contain reliably higher concentrations of boron and cobalt, tomatoes and cucumbers contain higher levels of chromium and vanadium, while silicon content is higher in vegetables from the Magadan Region. At the same time, neither of the examined samples exceeds the permissible levels of toxic elements.

Prediction of the physical-mechanical properties of metallurgical coke is an essential task from the viewpoint of its efficient application in the blast furnace process, in chemical industry, and also as fuel. The development of this task is the physical substantiation of the formation of coke piece strength. A method based on gasification is proposed to evaluate the size distribution of molecular oriented domains L_с(lamella height) and L_a(lamella length) indexes. It has been established through the analysis of the structure of large and small domains that large domains are less reactive in comparison with the small ones. For this reason, it is possible to use gasification with carbon dioxide to remove small domains leaving the large domains within the coke pieces. Results of the experiments provide evidence that mainly large domains remain in coke pieces after gasification. The indexes L_с and L_a were determined to increase approximately by a factor of 1.5 after gasification.

A systematic study of the relationship between the composition and structure of skeletal-dendritic ferrospheres isolated from fly ash formed in the combustion of Ekibastuz coal, carried out by means of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), allowed us to establish the general routes of their formation and the peculiarities of the influence of mineral precursors on their structure. The groups of globules were distinguished exhibiting a linear correlation between the content of silicon, iron and aluminium oxides in the gross composition of the polished sections. It is shown that the investigated ferrospheres are formed from the melt droplets of the general FeO-SiO₂-Al₂O₃-CaO system during their cooling and crystallization of individual phases. The formation of melt droplets occurs due to the sequential transformation of dispersed products from thermal conversion of mineral precursor associates, such as siderite, quartz, calcite and aluminosilicate components in the carbon matrix. The aluminosilicate precursor determining the structure of globules is hydromica of illite group. The crystallization of the ferrospinel of skeletal-dendritic globules occurs due to the “seed” of Al,Mg-ferrospinel, which is formed as a result of the thermochemical transformation of the illite of the initial coals. The observed general trend to changes in the structure of ferrospheres from coarse-grained crystalline skeletal type to fine-crystalline skeletal-dendritic globules is explained by a decrease in the content of the main spinel-forming oxides FeO, Al₂O₃ and MgO in the melt microdroplets.

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.

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.

Procedures for the control of iron content at all stages of the mechanochemical synthesis of lithium aluminates were developed. The procedures were proposed to determine iron content using two independent methods: molecular and atomic spectroscopy. Atomic absorption spectrometry should be used for iron content lower than 10^-3 mass %, as well as for aluminium-containing samples. It was found that lithium content in the sample up to 1 g/L does not affect the analytical signal of iron in the sample with iron concentration 2-5 µg/mL of iron when analyzing lithium carbonate by means of atomic absorption.