Microstructure of Coal before and after Gas-Dynamic Phenomena

The applicability of calculated information entropy to quantification of coal structure nonuniformity at a microlevel is demonstrated. The calculations used digital images of coal surface from scanning electron microscopy after thousandfold increase. The calculated statistical entropy-complexity values enable comparing structural nonuniformity of coal sampled from outbursts, as well as from outburst-hazardous and outburst-nonhazardous zones. It is found that coal from outburst-hazardous zones contain areas of highly chaotic structure as against the ordered structure of coal from outburst-nonhazardous zones. Outburst coal is free from chaotic structures though its structure is less ordered than in coal from outburst-nonhazardous zones. The proposed method allows detecting the certainly outburst-nonhazardous zones in coal seams using digital images of coal samples.