Study On The Recovery Of The Residual Coal Pillar In Room And Pillar Goaf Using The Paste Backfilling

The paste filling is one of the important content of green technology in coal minesystem. In recent years, Coal paste filling technology developed rapidly, receivedrecognition and attention from the majority of coal mining enterprises, got promotedin many coal mines, and good technical and economic results have been achieved, andthe system has been basically mature technology. Small coal mines In yulin of shanxiprovince use room and pillar mining method, leave a lot of residual pillar, lead to thelow recovery rate, have a lot of room and pillar goaf，buried the huge hidden troublefor goaf spontaneous combustion and large-area collapse.This paper puts room and pillar mining mine in yulin area as the background. Inview of the room and pillar goaf, Put forward to using paste filling method torecycling residual coal resources in room and pillar goaf and governance goaf. Bystudying the regional strata structure, paste filling material, filling body bearingcapacity，the technical basis is provided for the safety of the residual pillar recoveryand useful reference.In the first place，this paper research on stress distribution of coal pillarload before filling,the evolution of the overburden rock supporting system before andafter the filling process and the analysis of roof caving step distance of the study area.The researches provide theoretical basis for the paste filling mining scheme andrelated parameters design. In view of the specific conditions of studied coalmine,paste filling recycling residual pillar concrete solutions have been proposed.recycling residual pillar of room and pillar goaf in three stages use completebackfilling, recycling residual top-coal resources of room and pillar goaf use bandingpart filling. Aeolian sand and loess as filling materials, The article studied the optimalproportion of paste, evaluated the stability of paste filling support system, determinedthe strength of the filling body4MPa and2MPa. The last, The paste filling effect ofrecovery of coal resources is analyzed, The results showed that the paste filling caneffectively reduce surface subsidence and the surface buildings deformation wascontrolled in the permitted range.In this paper, The results of the preliminary study provides a new train of thoughtfor residual pillar resources recovery and room and pillar goaf management, Caneffectively promote the paste filling technology on the issue in room and pillar goaftreatment into practice.