Study on ultra-contiguous steep coal seams with combined mining method

Guo Zhongping; Wang Kai; Chen Jianjie

doi:10.13199/j.cnki.cst.2017.01.011

Abstract：In order to solve the problems of difficult roadway layout and poor ventilation during the mining of ultra-contiguous steep coal seams(thin and thick),two top coal caving methods including horizontal sectional step type top coal caving and false-inclined top beam overall combination suspend-shift support mining with sublevel caving were compared based on the geological conditions of the steep coal seams in Dawanqi Coal Mine in Baicheng of Xinjiang,and one method suitable for combined mining of ultra-contiguous steep coal seams was selected.Two ultra-contiguous steep coal seams were mined unitedly by excavating 30° inclined lane between them and forming a U-shaped ventilation,which actually was the horizontal sectional step type top coal caving method.Results indicated that the combined mining method improved the working environment in coal face,and reduced the labor intensity of workers and increased the production efficiency.The extraction rate reached to 85％ and the production capacity of working face was up to 0.4 Mt/a.