The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

225 / 2018-05-04 21:59:30

Effect of gas pressure on occurrence of gassy coal extrusion

Gassy coal extrusion,gas pressure,failure mode of coal,gas expansion energy

Gas of Coal Mine & Coal and Gas Outburst > Coal and gas outburst

In recent years, with the coal mining depth increasing, gassy coal extrusion occurs more and more frequently. Gas pressure, as a mainly influencing factor, has an important effect on the occurrence of gassy coal extrusion. To study on the effect of gas pressure on gassy coal extrusion, an analogous test device was developed to simulate gassy coal extrusion under different gassy pressure, and extrusion intensity, coal failure mode, variation laws of gas pressure were observed, and gas expansion energy was calculated. The results show that the increasing of gas pressure prompts increment of extrusion intensity and transferring of extrusion to outburst. With the increasing of gas pressure, the relative intensity of extrusion varies from 2.88% to 5%. When the dynamic phenomenon transfers to outburst, the relative intensity changes suddenly to 43.31%. During the process of gassy coal extrusion, gas release has an obvious sequence. When gas pressure is low, the release of gas pressure can be divided into two stages, and there is a stable stage or elevating stage. When extrusion occurred, gas near the occurring area of the dynamic phenomenon mainly participated. The gas expansion energy of extrusion is less, and the gas releasing speed is slow; during the process of gassy coal extrusion, the role of gas is mainly promoting the destruction of coal and extruding the coal.