The article presents experimental results of research concerning the action of weak electric and magnetic fields on physicochemical transformations in samples of hard coal with a previously destabilized microstructure. The actions of electric and magnetic fields are fundamentally different by many parameters. It has been shown that after treatment with a weak electric field, coal posted an electret potential with an anomalously continuous charge relaxation. Compared to untreated coal samples, the rate of methane emission from methane-saturated samples is maximum for long-flame coal and decreases as it approaches anthracite. The electric field stimulates the grinding of microparticles, a decrease in the maximum gas outlet temperature, a decrease in the enthalpy value in the formation of a new phase, and an increase in the chemical activity of treated coal samples. Fundamentally different results were obtained with magnetic stimulation of coals. In X-ray diffractograms of coal powders after magnetic treatment, the values of the maxima of the main peaks are the largest in comparison with the original samples and those treated with an electric field, which is consistent with an increase in the size of microparticles in a magnetic field. There is an increase in the heat of combustion and a decrease (by 5 times) in the loss of coal mass during heating.

This study aims to analyse physical and chemical changes in hard coal samples under the influence of low-intensity electric fields in comparison to the fragments of ejected coal, as well as the coal samples selected from the zones of high and low outburst hazard. We used physical methods including X-raying, electron paramagnetic resonance, thermogravimetric analysis, differential scanning calorimetry, laser diffraction analysis of particle sizes, IR-spectrometry, nuclear magnetic resonance, and Raman spectroscopy. It has been shown that destruction of coal organic matter (COM) can be caused not only by mechanical impacts or thermal influences but also weak electric fields. Scientific novelty consists in the fact that for the first time we established the identity of the COM destruction mechanism of mechanical-chemical activation and weak electric fields influencing on the previously destabilized coal microstructure. The destruction mechanism is based on thermal field regularities in both cases. The results obtained are of practical significance for the technologies of coal conversion to other products. The research results can be useful in the development of methods for reducing outburst hazard in coal mines.

Purpose. To establish the regularities of the influence of magnetic fields on the peculiarities of changing the chemical and structural characteristics of the coal substance according to the size of microparticles enriched with vitrinite. To formulate a new system of views on the mechanisms of structural and functional transformations of coal substance under the influence of weak external fields. Methodology. The authors used an electric furnace heating up to 320 K that creates a pulsation magnetic field with a strength of up to 4,000 A/m to process dispersed samples of hard coal with a weak magnetic field. The methods of infrared spectroscopy and electron paramagnetic resonance were used in the research. Findings. Experimental works were carried out to estimate the impact of weak fields on the state and properties of coal substance. It is shown that weak energy fields, and the electromagnetic one in particular, are able to reduce the energy barriers of reactions in coal substance due to spin-spin interaction, which leads to the activation of processes at the atomic-molecular level and interfacial interaction. Originality.It is experimentallyestablished that for coal micro-particles with sizes from 0.16 to 0.1 m, enriched with vitrinite, the coupling coefficient decreases after exposure to an external magnetic field, and for micro-particles with sizes less than 0.63 m, this indicator increases. Such changes are caused by the redistribution of hydrogen between aromatic and aliphatic components during free-radical reactions. Changes in the spectrum on vitrinite (0.160.10 mm), are more significant than on inertinite (0.063<0.05 mm). At the same time, the external action of the electromagnetic field has caused the opposite consequences. It is shownthat magnetically stimulated chemical reactions occurring in the coal substance are aimed at the recombination of free radicals with active surface states of the organic mass of coal into stable gas molecules. The results of laboratory studies using the methods of electron magnetic resonance and infrared spectroscopy and infrared spectroscopy allow assuming that the changes in structural characteristics recorded during experiments with low-energy impacts can be considered as intermediatorsfor the matter transformation or changes in the state of coal in preparation for structural and functional transformations.For example, to the sorption interaction or destructive processes with methane generation. Practical values.The magnetic field effect can be used to develop new research methods for the study on elementary processes by electron spin resonance; control spin-dependent phase transitions. The use of magnetic resonance methods allows the usage of magnetically field effects in the form of basic tools for the research on structural defects. The results obtained will be a scientific ground for the development of methods for estimating the parameters of electromagnetic processes in coal to develop new technologies for the extraction and processing of hydrocarbon energy carriers.

The research was carried out by means of implosion plasma generators with conical and hemispherical compression chambers to conduct a quantitative assessment of the boundary temperature of super dense plasma jets. It was proved experimentally that nuclear transformations in metals are caused by the impact of super dense plasma jets (11, ..., 12) × 10³ kg/m³. The boundary temperature of these jets was evaluated. It was estimated that the nominal boundary temperature of the studied implosion plasma generators is 10⁶ К. The pressure in the target at the penetration of the super dense jet (~12,000 kg/m³) at the speed of 28,000 m / sec is more than 30 ТPa. The boundary temperature was estimated and proved to depend on the pre-determined values only slightly. It was experimentally established that stable isotopes of manganese Mn⁵⁵ (up to 27%) are formed in iron targets as a result of high temperature plasma jet penetration. The appearance of manganese must be related to iron transformation into stable isotopes Fe⁵⁶ and Fe⁵⁴. The obtained results may be applied for investigating structural changes in metals under the conditions of impulsive super high temperatures and pressures. This method can be also used as a testing ground for studying the physical conditions of forming chemical elements as well as super dense plasma jets.

Purpose. To synthesize diamond polycrystals in a thermodynamically stable region, and to grow up a single crystal shell under conditions of thermodynamic metastability. To investigate some physical properties and features of the internal structure for synthesized single crystals for the development of new models and hypotheses regarding the issue of diamond genesis. Methodology. Experimental studies using shock-wave effects on a metal alloy containing non-diamond carbon. Methods of infrared and ultraviolet spectroscopy, X-ray phase analysis, electron paramagnetic resonance, isotope analysis, differential thermal analysis, electron microscopy, and others are used. The synthesis of nanocrystalline diamond particles as nuclei for growing single crystals is carried out by the shock-wave method using profiled shock waves. Findings. A complex of physicochemical methods for studying the grown diamond monocrystals has been carried out. The reasons for the discrete growth of diamond and the retention of the central inclusion (a polycrystalline diamond of shock-wave origin) in the process of growth have been established and analyzed. It is shown that the discreteness of diamond formation is characteristic only for thermodynamically metastable conditions. The results of the experiments give grounds to make an assumption about the metastable growth, including of diamonds from primary deposits. Originality. The hypothesis has been developed concerning the origin of diamond nanoparticles in interstellar carbon clouds which refer exclusively to central polycrystalline inclusions in a monocrystal diamond shell. The hypothesis eliminates the scientific contradiction that arises in all cases when attempts are made to interpret the natural discreteness of diamond formation based on the regularities of the graphite-diamond state diagram. Possible causes of discrete diamond formation in nature and the scenario of the formation of diamond nanocrystals in an interstellar cloud of atomic carbon have been considered. Practical value. The value of the experimental research results refers to the development of a non-energy-intensive technology for the growing large diamond monocrystals at temperatures of 5001400 K, and pressures of 105107 Pa.