Elimination of Coal and Gas Outburst Dynamic Disasters in Dengfeng Coalfield through Gas Extraction Based on Extremely Thin Protective Coal Seam Mining

<table class="table-group" id="tab2"><tr><td><table class="table"><tr><td class="thead-hr" colspan="9"><hr/></td></tr><tr class="thead"><td class="align_center" colspan="3">Permeability coefficient (mD)</td><td class="align_center" colspan="2">Gas pressure (MPa)</td><td class="align_center" rowspan="2">Gas extraction rate (%)</td><td class="align_center" colspan="2">Gas content (m<sup>3</sup>/t)</td><td class="align_center" rowspan="2">Measured expansion displacement of coal seam (mm)</td></tr><tr class="thead"><td class="align_left">Original</td><td class="align_center">After relief</td><td class="align_center">Additional magnification</td><td class="align_center">Original</td><td class="align_center">After relief</td><td class="align_center">Original</td><td class="align_center">Remnant</td></tr><tr><td class="thead-hr" colspan="9"><hr/></td></tr><tr><td class="align_left">0.0012</td><td class="align_center">0.473</td><td class="align_center">394</td><td class="align_center">1.17</td><td class="align_center">0.12</td><td class="align_center">68</td><td class="align_center">9.74</td><td class="align_center">3.1</td><td class="align_center">72</td></tr><tr class="table-tr"><td colspan="9"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>The investigated relief protective effect parameters of No. 2<sub>1</sub> coal seam.</div>

Advances in Civil Engineering

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Table 2

Table 2: Elimination of Coal and Gas Outburst Dynamic Disasters in Dengfeng Coalfield through Gas Extraction Based on Extremely Thin Protective Coal Seam Mining 

Table 2 | Elimination of Coal and Gas Outburst Dynamic Disasters in Dengfeng Coalfield through Gas Extraction Based on Extremely Thin Protective Coal Seam Mining 