№60-10

Conversion of the coal microstructure affected by weak electrical fieldaction

T. Pichka¹

¹Institute for Physics of Mining Processes National Academy of Science of Ukraine, Dnipro, Ukraine

Coll.res.pap.nat.min.univ. 2020, 60:106-115

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ABSTRACT

Purpose. Study of physicochemical changes, which take place in coal microstructure after being treated with low-voltage electric fields.

Methodology. Used coal samples, have follow characteristics: carbon content 86.9%, hydrogen 5.6%, vitrinite reflectance R₀ ≥ 1,04 %, Y = 19 мм, W = 1,4%, V^daf = 31,3%, combustion heat Q^daf = 35560 kJ/kg. Low voltage electric fields up to 200 V/cm were used. Physicochemical characteristics study was carried out in research laboratories of SE NPP "Pavlograd Chemical Plant" using optical microscopy with differential scanning calorimetry, laser diffraction analysis of particle sizes, infrared spectroscopy and other.

Findings. Experimental studies, included coal samples preparation for electromagnetic treatment. After treatment with weak electric fields, were studied physicochemical changes in treated coal samples. To compare results of coal microparticles electric field treating we can see the tendency in microparticles fractional composition change with weak magnetic field.

The originality. Effect of changing coal microparticles granularity in a weak electric field was established, it means that microparticles content increases in size, when largest in size decreases. This effect based on the fact that deformed (destabilized) chemical bonds excitation, even with low electric field strength; it leads to microparticles destruction and corresponding gas generation. Weak magnetic field impact leads to repeated increase of maximum grain size in microparticles size. Assumed that magnetic fields action stimulates spin-selective chemical reactions between moving components and microparticles surfaces.

Practical implications are that s obtained experimental result will be useful for physico-mathematical modeling of solid phase fracture mechanisms, not only under thermobaric influences, but also of weak electric fields tensions. Particular importance of these works in new non-energy-intensive technologies development for processing coal into gas and liquid components.

Keywords: microstructure destabilization, destructuring, field strength, chemical activity.

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