Influencing Factors Of Gas Emission And Their Correlativity In Fully Mechanized Mining Face Of Pingdingshan Fifth Mine

Gas is one of the main influencing factors in the coal mine safety production, which plays a very crucial role in the coal mining enterprises. Severe and great gas accidents often result to a large number of casualties and significant economic losses in coal. Therefore, the study about influencing factors of gas emission quantity in coal mine will be very significant for coal mines. In this dissertation, 23260 face of six-coal in Pingdingshan Fifth Mine was taken as the object of study. The methods such as the theoretical analysis, numerical simulation and field measurement methods, and so on, were used. The impact factors of gas emission in the coal face were studied and analyzed systematically.Analysis indicate that there are a few main factors influencing the gas emission in 23260 face of six-coal which including coal permeability, mining stress and gas pressure and roof cycle pressure and gob gas field. Coal seam permeability is a key factor in the face influencing gas emission, which determines the transport properties of coal seam gas. Mining stress has a great influence on the pore and fracture structure of the coal which locate in front of the coal face. Mining stress could influence the face gas emission by affecting the wall structure of coal seams in different regions in front of the coal face. The mining stress greater, the lower of the coal permeability in the peak stress region, and the more difficult of the gas emission before the coal with pressure relief. The gas pressure and the permeability of coal seams are negatively related.Gas pressure has a relatively large impact on the expansion relief regions’ gas adsorption activity in the front of the working face. In the original coal region, gas pressure will lead to coal seam permeability more lower and gas emission more hardly. Meanwhile, the gas pressure could easily lead to the expansion and the relief seam zone gas gradient become larger, that the amount of gas emission abruptly, easily lead to the occurrence of gas disaster. Periodic pressure and working face gas emission has certain correlation,and the peak of gas emission comes later 1-2 days than periodic pressure. In the period Periodic Roof, that not only caused the gob gas flood the face, but also made the face seam suddenly relief because of the roof collapse, which lead to the seam permeability become larger and could increase the gas emission, these two factors caused the increase of gas emission in stope.