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A systematic study employing scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS) of ferrospheres isolated from the fly ash formed in the combustion of pulverised coal of the Kuznetsk basin allowed us to determine the glass phase composition. The groups of globules have been identified for which the gross composition of polished sections exhibits a linear correlation between the content of glass-forming silicon and calcium oxides. Heterogeneity of the glass phase of the studied ferrospheres in composition and the number of its components was established. It is shown that iron is mainly found in the crystallites of iron-containing phases, and silicon is in the glass phase. The remaining elements are distributed between these phases. It is shown that ferrospheres contain microglobules of varying compositions, with sizes of less than 1 mm, localized in the amorphous glass phase. Their presence determines the chemical heterogeneity of the glass phase. The composition of microglobules, like the composition of ferrospheres as a whole, is determined by the mineral components of the original coal. The precursor for the formation of the glass phase of ferrospheres are aluminosilicates of original coal.

The possibility to generate acetylene by pyrolysis in hydrogen plasma was determined using thermodynamic calculations taking into account the elemental composition, temperature range, and the C/H ratio for coal samples from six open-cut mines of the coal deposits of Eastern Siberia: the Mugunsky production site of Tulunugol (ZBR coal rank, the Irkutsk Region), Chadan (GZh coal rank, the Republic of Tyva), Zalushansky (D coal rank, the Trans-Baikal Territory), Irbeysky (2BR coal rank, the Krasnoyarsk Territory), Cheremkhovugol (G coal rank, the Irkutsk Region), Kaakhem (G coal rank, the Republic of Tyva). Results of thermodynamic calculations for the listed coal samples demonstrate the possibility to obtain acetylene from all the six coal ranks under consideration. These results can be used to develop the technology for obtaining acetylene and other compounds by the hydrogen-plasma pyrolysis of coals from the deposits of Eastern Siberia.

The dependence of the indicators of thermal decomposition of coal from the Kuzbass and Pechora basins on coal moisture was studied when determining the liability of coal to spontaneous combustion by thermogravimetric analysis. The rates of mass change were calculated, and characteristic temperature points were determined (the onset of mass increase, and the maximum rate of mass change) by heating the coal samples within temperature ranges 120-300 and 300-900 °C. It has been determined that the rate of mass gain within the range of 120-300 °C is 10 times higher for the coals of the Pechora coal basin, prone to spontaneous combustion, while within the range of 300-900 °C it is independent of the tendency of coals to spontaneous combustion. It is shown that with an increase in the moisture content in coal, the rate of thermal decomposition of coal increases with an increase in moisture content within the temperature range of 25-200 °C. Moisture content of coal was not detected to affect the parameters (the temperature points of oxidation onset and mass gain) characterising coal oxidation reaction in the studies by thermogravimetric analysis.

As a result of studying the phase composition of Ni-Pt nanoalloy particles using X-ray diffraction (XRD) analysis, it has been established that during the synthesis of Ni-Pt nanoalloy particles by co-reduction of the aqueous metal precursor solutions (Ni²⁺ and [PtCl₆]^2-) with an alkaline hydrazine hydrate solution, the formation of fcc-type Ni-Pt solid solution particles occurs, with an average Ni content of 13 at%. These particles have ellipsoid shape with the equatorial and lateral size 6-13 and 10-28 nm, respectively. By comparing the XRD results with data obtained from high-resolution transmission electron microscopy (HRTEM) and small-angle X-ray scattering (SAXS), it has been shown that, in addition to the aforementioned Ni-Pt solid solution particles, the synthesised samples contain ultrafine Ni-rich particles: the phases of Ni-Pt intermetallides and the fcc-phase of individual Ni. As a result of heating the sample with total nickel content 20 at% in high vacuum to a temperature of 390 °C, the phase transformation takes place, leading to the formation of fcc-type Ni-Pt solid solution particles with Ni content 23 at% and average size ≈26 nm, as well as the particles of practically pure platinum with the average size ≈55 nm.

The problem related to processing and disposal of ash and slag waste from thermal power facilities has not been solved in Russia as a whole, and particularly in Kuzbass. In the present work, we studied ash and slag (slag, fly ash from Kemerovo and Belovo heat plants, and Kemerovo power plant) and related wastes (cake and ore from the enrichment plant) from the enterprises of Kuzbass using physicochemical methods to assess the optimal ways of their processing. X-Ray diffraction analysis has shown the presence of quartz in all the studied wastes, carbon-like phases in rocks and cake, and vitreous phases in all slags and the vast majority of fly ash samples. The materials were analysed by atomic emission spectroscopy with inductively coupled plasma after autoclave preparation of the sample with a mixture of nitric and hydrochloric acids. X-Ray fluorescence analysis was performed for rocks and cake. Element content in samples, assessed from atomic emission analysis data, correlates with the data of X-ray fluorescence analysis. Fly ash, ash and slag wastes differ from each other in composition: fly ash is characterised by lower magnesium and iron content. It is shown that glass formation in ash and slag at high combustion temperatures complicates the acid extraction of elements. The method of acid leaching with nitric acid followed by precipitation with a solution of ammonia and oxalic acid was tested. Rare earth elements are observed to concentrate in the fraction of insoluble hydroxides, where aluminium prevails as the major element; in particular, europium is concentrated up to 144 g/t. Low calcium content, high silicon and aluminium content allowed us to propose manufacture of silicate products with the possibility of isolating rare and rare earth elements as the main way of processing the wastes from the enterprises of fuel and energy complex of the Kemerovo Region (Kuzbass).

The work is focused on the preparation of zinc ferrite and study of its catalytic activity in the phenol ozonolysis reaction in an aqueous medium. Zinc ferrite was synthesised by co- precipitation of the hydroxides with ammonia solution, followed by hydrothermal treatment of the precipitate at a temperature of 160 °C. The product was characterized by X-ray diffraction and infrared spectroscopy. The catalytic activity of zinc ferrite in phenol ozonolysis was studied. It has been determined by UV-Vis spectroscopy that the products of phenol oxidation are cis,cis-muconic acid (absorption in the region of 300-400 nm) and 1,4-benzoquinone (absorption band at 237 nm). It is shown that the addition of zinc ferrite not only accelerates phenol ozonolysis but also causes deeper oxidation; 1,4-benzoquinone is not formed if the catalyst is absent. The data obtained can be used to develop new water purification technologies based on a combination of ozonation and heterogeneous catalysis.

The results of an experimental study of high-temperature plasma gasification of mixed organic fuel based on sawdust and coal washing waste (hereinafter referred to as coal) are presented. The relevance of the work is due to the need to develop effective and environmentally friendly methods for processing renewable raw materials in the context of increasing energy consumption and tightening environmental standards. Gasification of individual components (sawdust, coal), their mechanical mixtures and composite materials obtained by their joint activation milling in various ratios was studied. The experiments were conducted in a plasma-thermal unit with a capacity of 20 kg/h with an arc plasma torch (50 kW) at temperatures of 1200-1600 °C. The experiments showed that the maximum concentrations of the target components of the synthesis gas were achieved during gasification of a mixture containing 66 % sawdust and 33 % coal. In this version, the hydrogen content in the gasification products reached 9.91 vol%, and carbon monoxide - 28.04 vol%, which indicates a high efficiency of processing such a fuel composition. Analysis of the gas evolution dynamics revealed that in comparison with mechanical mixtures, the composite samples obtained by the joint activation milling provide a more stable and uniform yield of synthesis gas throughout the gasification process, which is important for the practical application of the technology. The studies have shown that the combined processing of biomass and coal in the form of composite materials allows optimising the gasification process, ensuring uniform gas emission and reducing harmful emissions. The results obtained are of practical importance for the development of energy-efficient and environmentally friendly technologies for processing organic waste.

Hollow aluminosilicate microspheres (cenospheres) of stabilised composition (glass phase - 95.4 wt%; (SiO₂/Al₂O₃)_glass - 3.1) isolated from coal fly ashes from coal combustion were used to prepare composite sorbents containing a sorption-active component based on zirconosilicates of framework structure. The synthesis products were characterised by X-ray diffraction analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and their sorption properties for Cs⁺, Pb²⁺ and Cd²⁺ cations were studied. The zirconosilicate material shows a high distribution coefficient in the process of sorption of Cs⁺, Pb²⁺ and Cd²⁺ from aqueous solutions (10³-10⁵ mL/g). For Pb²⁺ as an example, it is shown that as a result of high-temperature phase transformation of the Pb²⁺-form of zirconosilicate, Pb²⁺ cations are stabilised in the crystalline phase of lead zirconate PbZrO₃. The possibility to use spark plasma sintering for obtaining mineral-like ceramics based on zirconosilicate sorbent for immobilisation of radionuclide Cs-137 has been investigated. For ceramics sintered at different temperatures (800-1000 °C) the cesium leaching rate was studied, which is a criterion of hydrolytic stability of radioactive ceramics intended for disposal in rocks. The obtained values of leaching rate (~10^-5 g/(cm²⋅day)) meet the requirements of Federal Norms and Rules in the area of atomic energy use NP-019-2000 “Collection, processing, storage and conditioning of liquid radioactive wastes. Safety requirements”.

Modes of modification of carbon material obtained from wood raw materials are described in order to improve the electric capacitance characteristics for subsequent application as an electrode material in supercapacitors. The effect of two modification methods is considered: treatment with hydrogen at 1000 °C, treatment with a concentrated solution of hydrogen peroxide (37 wt%) at 60 °C. It is revealed that the greatest improvement in the functional properties of the material occurs when it is treated with hydrogen peroxide. Analyzing the sorbometry data, it was found that the specific surface area of the sample modified in this way increases by 20 % due to the formation of micropores. In this case, according to IR spectroscopy data, electrochemically active carbonyl groups are formed in the sample. Testing of the obtained electrode material in a model electrochemical cell simulating supercapacitor operation revealed an increase in its electrical capacity by 60 % relative to the initial sample.

An integrated method of mining quarry reclamation and landscaping is presented. The essence of the method is in making a protective layer of gel-forming composition, based on polyvinyl alcohol (PVA) and IKhN-PRO composition, including borax, on the surface of solid toxic rock. A fertile ground containing plant seeds is applied onto the surface of the protective layer; its surface is treated with a solution of PVA mixture and carboxymethylated starch (CMS). After the freezing-thawing cycle, soil-structuring cryogel is formed, which retains moisture, heat and makes comfortable conditions for plants. The rheological properties of the gel-forming composition were investigated; the time of gel formation at a temperature of 20 and 10 °C was determined to be 200 and 150 seconds, respectively. The rheological characteristics of the solutions of PVA and CMS mixture were studied. It is shown that with an increase in the polymer concentration in the mixture the viscosity increases. Dry films obtained on the basis of a mixture of PVA, CMS and cryogels swell in water. Phytotoxicity of the method was studied for coal samples. The biometric data of plants have shown that the productivity of plant biocenosis in experimental samples is much higher than in control samples.