Coordinated Mining Technology of Contiguous Ultra Thick Seams in Mine with Annual Production over 10 Million Tons

In order to realize the coordinated mining in contiguous ultra thick seams, taking No. 4 and No.9 seams in Pingshuo Mining Area as the study objects, th e theoretical analysis, numerical simulation and the site observation method were applied to determine the top coal caving parameters of the coal mining face, gateway layout mode, gateway support mode, sectional coal pillar size and terminal mining line location. The results showed that the fully-mechanized top coal caving mining fac e in No.9 seam with one cutting and one caving, sectional and twice sequence top coal caving could improve the coal mining recovery rate by 2.1%. Based on the enh anced gateway support of the coal mining face in No. 9 seam, an internal and external dislocated combined gateway layout mode applied could effectively prevent the C oal wall spaling and roof falling accident occurred. When the sectional coal pillar size of the coal mining face in No.4 seam was not less than17 m and the terminal min ing line had a distance of 50 m to the mine main roadway, thus the stability of the mine roadway in No.4 seam and the water bunker in No. 9 seam could be effectively ensured.