| Coal is Chinese basic energy, and gas has always been a major factor to threat the safety of coal mine production seriously. With the increasing depth of underground mining, the increasing pressure of gas, the increasing mechanization of mining work, and the increasing extractive strength, the gas disaster will be more and more serious. The technology of Tunnel drilling hole striped seam gas pre-drainage, both coal and gas extraction to achieve an extraction technology, but also a proven technology outburst. Problem of the Huainan coal is seam permeability is poor. The pre-pumping of not-relief coal seam, not only large projects, and the effect is not ideal. Through the combination of theoretical analysis and field tests, this article analysis the drilling hole band-style pre-drainage gas outburst mechanism and methods systematically. Use pressure method to measure the coal seam extraction radius had a reasonable layout of drilling. And test drilling hole striped method of pre-drainage gas in the LiZuiZi coal mine, the experiment shows that using drilling hole striped pre-pumping gas to the low permeability coal seams, pre-pumping the residual gas pressure after the Bllb is 0.04MPa,0.16MPa than the original gas pressure drop 75%, B9b 75d after coal pre-pumping the residual gas content than the original gas content decreased by 70% or so. Fully reflects the drilling hole pre-pumping striped effect outburst of gas relief. Cover tunnel is 3232 (1) machine roadway average 228m/month. Than 3231 (1) Machine average speed roadway 133.8m/month increased 94.2m. For the seam dip angle, occurrence of instability LiZuiZi mine, Excavating drilling hole than the failure to take measures to pre-pumping time 133.8m/month increased 70.4%. While 3232 (1) machine Lane in the tunneling had not happened the phenomenon of predictor overrun. Provide protection for the safe and efficient production.Figure [27]; table [28]; reference [53]... |
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