Lagged top coal caving technologyat the ends of fully mechanized top coal caving faces

CUI Yongqing; ZHAO Baoyou

doi:10.11799/ce202507001

Abstract：To address the technical challenges of top coal recovery at face ends which is located over roadways and transition supports in thick-seam fully mechanized top coal caving face,based on the deformation characteristics of the roof strata at the face ends,a technology of face end top coal recovery through lagging coal caving supports at the face ends in a fully mechanized top coal caving face is proposed by combining theoretical analysis,numerical simulation and field application.The caving-capable supports in the face end are arranged 2～3 m lagging behind the working face supports toward the goaf,and the transfer conveyor and the rear scraper conveyor are extended to the end of the coal caving supports in the working face end.At the same time,the transition supports with coal caving function are adopted,and the top coal of the whole working face and the top coal of the entry can be recovered using the coal transportation equipment of the original working face.Multiple validated top coal fracturing technologies are implemented,including anchor withdrawing,mesh cutting,gas explosion fracturing,and static expansion fracturing.The technology was applied in Sanyuan Coal Mine and the results showed that,about 72 tons of top coal resources can be additionally recovered for every 1 m mining,and the recovery rate of the working face is increased by 2.5%,achieving safe and efficient extraction of roadway roof coal and transition hydraulic support-top coal.