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The Russian Federation is one of the world leaders in coal mining. The Russian coal branch is one of the key industries of the Russian Federation. Currently the government carries out measures for restructuring of the Russian coal industry. One of the major factors of coal branch sustainable development is to focus on foreign markets in condition to meet the demands of domestic market. One of the priority directions of the Russian coal industry development is providing trade of hi-tech power product. Thus consider...

The paper presents results of experimental study of microstructural changes in rock specimens under the effect of high pulse pressure due to shock waves. Specimens of strong rock and coal were placed into special steel preservation ampoules. Shock waves were generated by explosion of trotyl blocks. The study involved electron microscopy, micro- and nanoindentation and laser spectroscopy of particle size. Images of specimen surface fragments were obtained by electron microscopy at various scale levels before and af...

In the paper the problem of coal permeability enhancement by hydraulic fracturing with the lightweight proppant is considered. The used proppant consists of hollow aluminosilicate microspheres ASPM-500. The experimental results of the lightweight proppant influence on the long-flame coal permeability are presented. The permeability of coal with a propped crack is reduced by 4-9 times as the confining pressure is increased by 5 times from 1 to 5 MPa. The permeability decrease may be caused by the proppant pack comp...

Obtaining more data on coalbeds in advance will presumably enhance the whole coal production process. Therefore, there is a need to employ a method of mechanical logging, which is able to provide data on coalbeds, including such parameters as coal seems thickness, depth of a coal seam?s roof, and coal ash content. Since drilling and blasting operations are inevitably used to burst overburden rocks, it would be much more efficient to employ them in extensive and accelerated data extraction. In some cases, the dista...

Adsorption of CO2 and N2 onto coal is used to describe its porous structure. It is mainly CO2 that allows for the analysis of the adsorption on coal, whose porous structure is dominated by micropores. Depending on the specificity of the transition process of CO2 molecules from the free state to the adsorbed state, the thermal characteristics of the adsorption process varies as well. The article presents the test results of three types of coal from Polish mines. The researcher carried out volumetric analyses of gas...

This paper addresses mechanisms of destruction of methane-saturated coal at micro- and macro-levels under dynamical impact due to methane transition from its natural bound to a free state. The focus is on possible destruction of practically impenetrable (crushed and pressed) coal. Our study is based on analysis of experimental investigations and computed modeling. The experimental investigations involved experiments with rock pre-cracking under explosive impact and analysis of photo images of coal microstructure a...

An important source of hydrocarbons is coal which is often associated with oil deposits. In the Volga-Ural oil and gas province (Russian Federation) coal resources in the Visean deposits of the Carboniferous Period exceed 3.5 billion tons. They are located at depths of about 1 km and are inaccessible to mine operations. At the same time, coals can be exploited by well methods as a source of gaseous raw materials. The power gas from coal seams can be used in the development of deposits of high-viscosity oils in adj...