Study on mining technology to further improve production in fully-mechanized coal mining face with large mining height

Based on the current state of fully-mechanized coal mining with large mining height technology and equipment,the paper analyzed the factors of large-scale development and studied approaches to further raise production volume at in fully-mechanized coal mining face with large mining height. The paper summarized the followi ng major factors of the large-scale development.First,there was a large and stable coal reserve in China with seam height ranging at 3.5 ~ 7.0 m,and most coal seams had small dip angle.Second,function parameters and performance of the coal mining equipment had been improved and most of the equipment were produced domestically in C hina and no longer needed to import. Third,the movement rule of rock strata in large mining height had been further understood through studies. It's learned that rock strata in the roof of large mining height tend to form into a structure of " inverted-steps-like short cantilever rock beams-hinged rock beams" .With the increasing of mining height,t he sphere of influence from pilot support pressure and its peak value would increase remarkably.The movement range of overburden rock strata in both horizontal and verti cal direction would enlarge. The coal wall tended to fracture at 0.35 time higher of the mining height above the working face,and then the coal wall would cave in.Such rule helped the application of coal mining machinery into coal mining technology.