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

<div>Schematic diagram of coal seam gas pressure grouting method: (1) air charging system; (2) three direct links; (3) pressure gage; (4) wooden wedge; (5) piezometer tube; (6) coal seam; (7) blocking material; (8) injection pipe; (9) grouting pump; (10) holder; (11) small holes.</div>

Advances in Civil Engineering

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Figure 4: Elimination of Coal and Gas Outburst Dynamic Disasters in Dengfeng Coalfield through Gas Extraction Based on Extremely Thin Protective Coal Seam Mining 

Figure 4 | Elimination of Coal and Gas Outburst Dynamic Disasters in Dengfeng Coalfield through Gas Extraction Based on Extremely Thin Protective Coal Seam Mining 