Study On Surrounding Rock Control Technology Of Working Face On Old Residual Coal Mining

Coal is China’s basic energy and accounts for about70%of primary energy structure,which will not change coal is given priority to energy production and consumption pattern in the coming decades.However,with the continuous mining during the recent years and the backwardness of the mining method, the recovery rate of less than30%, resulting in the quality of coal resources less and less.For example, the old mining of coal seam8of Shenda Group Wangtian Coalmine in Xinzhou city of Shanxi province, due to the crude and small production mode and the backward coal winning method, resulting in using barrier or to dig generation from coal mining and other mining methods, which led to serious resources loss. Now, it becomes more and more importan how to recycle and use of resources have been wasted. It’s an effective way to solve the problem to recycle the remaining coal resources. Due to the complexity of the old residual coal mining, the recycled process of coal faces many technical problems, specifically,it’s a serious problem that the control technology of roof in the working face.The paper is given priority to with the preservation state of the left-over area and mining conditions in coal seam8of Shenda Group Wangtian Coalmine in Xinzhou city, and adopt longwall fully mechanized coal mining method is proposed of recovery of residual coal mining technology solutions. With the theoretical analysis, field research, methods of numerical simulation, in the residual coal occurrence mode on the basis of investigation and study of the old mining residual coal district wall surrounding rock stress distribution rule of fully mechanized working face. The research content and conclusions are as follows:1、Through analyse the occurrence structure of coal seam8of the old mining residual coal district, preliminary seven roof mechanical model is established. According to field investigation and observation, five of seven kinds of roof mechanical model as the research object of hope field of coal mine.2、Through theoretical analysis, the system of argument when single point pillar stress above the central pillar roof space stress is maximum; More stress, the coal pillar roof above the coal pillar largest stress; When the coal pillar width more than7.73m, the old mining area left in the residual coal with coal pillar support ability. 3、Using RFPA numerical simulation software, the system analysis of old mining area coal mining coal mining face entity residue, coal pillar and working face in front of coal pillars and mining in different coal pillar spacing of surrounding rock stress distribution law.4、Through the field analysis of the five kinds of coal mine roof mechanical model, summed up the old mining residual coal district secondary stoping in the three states position relationship between supports and surrounding rock during the process:①The state of coal cylinder②The state of support null zone above;③The state of a alley. And summed up in two kinds of roof management method, respectively, for the old mining area residual coal mining of coal pillar mining face roof control and old mining area the residual coal mining working face through empty roof when the top and empty lane management two management way, according to different management methods put forward the corresponding control technology.Based on the analysis of the above research, in the old mining residual coal district wall surrounding rock control technology of fully mechanized working face in more depth, we will further improve the longwall mining when the residual coal working face surrounding rock control technology measures. To different way of roof management face will face technical problems, put forward different attempts.