Controlling Function Of Characteristics Of Surrounding Rock Mass On Gas Occurrence And Emission

The mine methane is the combination of the harmful gases underground, which mainly derives from the gases in the coal seam and the gases in the surrounding rock that host and emit into the mine. And the mine methane is the main factor which effects the coal mine safety production. By the exploring of the sixth mining area of the northern Taoyuan mine, studying of the production stage geology and analyzing the data of the methane's field experiments, this paper has grasped the law of the methane subsection and the storage state, and gained the answer that the characteristics of the surrounding rocks have effected on the methane occurance and emission. So this research will play the instructive role on predicting the methane emission.Based on collection and analysis of the primitive data , and by means of using relativity analysis methods of the mine statistical analysis mathematics and geological statistics, this research has studied that the surrounding rocks of Taoyuan mine have effected on the methane occurance and emission ,besides, in order to gain the methane delivery law, the research divides grades about the fissure in combination with the bored core's fissure structural surface density, and then pretects the mine methane emission rate by divition method And this research plays the impoint point on studying the effection of the fault which be exploded by the mine area to the methane emission.The result of the research has showed that the roof is made of three obvious zones, and the roofs of shallow and profound coal seams are the mudstone with poor permeability, the roof of middle coal seam is mainly the medium particle sandstone or the middle-fine sandstone with better permeability.The cementation degree of the roof sandstone, which is mainly the calcareous cement and travertine, is poorer. And the fracture is less developed, and there are some obvious fissure development zones. The surrounding rocks have obvious control action on the coal seam and the methane hosts in the surrounding rocks. The shallow and profound roof mudstones have the good sealing as barrier layer, and they can barrier that the methane occurred in the tenth coal seam dissipates to the surrounding rocks. The methane of the shallow coal seam will dissipate out of the coal seam by wind oxidize belt, and the profound one will also dissipate up the coal seam to the central block and the roof sandstone pre-existing fractures with the methane of the middle coal seam, and then it will dissipate to the surrounding rocks of the roof sandstone and reserve in them. The coal seam methane content in the central block is relative lower, and the methane pressure has not gotten to the critical value of the gas outburst pressure.