Fragmentation of Coal Samples upon Intense Dynamic Impact

Explosive dynamic impact on coal samples placed in steel storage ampoules is investigated experimentally. The structural features of coal and the nature of its fragmentation are studied via electron microscopy and laser spectrometry for particle size. The different reaction of coal to the impact was determined, depending on the content of gas (methane) in them and their predisposition to dynamic gas destruction. A high share of particles with sizes of around 0.1 microns is observed in disintegrated samples of coal containing methane and prone to dynamic gas destruction, while particles with sizes on the order of several microns formed a substantial fraction of other coal samples. The main phenomenological difference was that storage ampoules with gas-containing coal were partially destroyed during the tests. The possibility of using the results from coal tests to predict hazardous dynamic gas phenomena in mines is considered.