Increasing Permeability of Coal Seam and Improving Gas Drainage Using a Liquid Carbon Dioxide Phase Transition Explosive Technology

Figure 14

Variations of gas pressure as a function of time: (a) borehole spacing between the drainage hole and the blast hole is 3 m; (b) borehole spacing is 4 m; (c) borehole spacing is 5 m; (d) borehole spacing is 6 m.

(a)

(b)

(c)

(d)