Destabilization of the hard coal microstructure by a weak electric field

¹ Institute for Physics of Mining Processes National Academy of Science of Ukraine, 2a Simferopolska St., 49005 Dnipro
² National Mining University, Department of Hydrogeology and Engineering Geology, 19 Yavornytskoho Ave., 49005 Dnipro, Ukraine
³ National Mining University, Department of Construction, Geotechnics, and Geomechanics, 19 Yavornytskoho Ave., 49005 Dnipro, Ukraine

^* Corresponding author: rudakovdv21@gmail.com

Abstract

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.