Analysis of characters of No. 9 coal seam gas occurrence of middle-deep part of Yunnan Dahe Coal Mine

No. 9 coal seam of Yunnan Dahe Mine is located in the upper part of the coal bearing strata,is the most widely distributed and the thickest minable coal seam.The coal seam is charactered by stable position,gentle incline,bearing in the middle-deep part, shallow edge,3.50 meters deep average. The coal seam is made up of coking coal,1/3 coking coal and a small amount of fat coal,the coal has high gas generating rate,high adsorption rate(greater than 15 m3/t)and high desorption rate(more than 70%),those sre favorable to the enrichment and high yield of coalbed methane. Study on the characteristics of this region is of great guiding significance for similar exploration of coalbed methane.