Safe and efficient mining technology for high-level top coal caving working face in large inclination downward mining of Qingdong Coal Mine

DING Weiping; MA Chao; PAN Weidong; ZHAO Zhining

doi:10.11799/ce202412040

Abstract：Fully mechanized top coal caving technology is suitable for the working face of thick and extra-thick coal seam,for improving the recovery rate of resources,mining-excavation relay of tense mines have unique advantages.With the upgrading of equipment and the deepening and development of research,fully mechanized top coal caving mining technology has been widely used in a variety of coal mining conditions.The coal seam of No.832 working face in Qingdong Coal Mine has large dip angle and thick coal seam.If the traditional low-level coal caving method is adopted for coal caving,the coal and gangue can not effectively enter into the slot of the rear conveyor,and are scattered in the rack or channeled into the working face,leading to serious coal left in the goaf,increasing the cleaning workload of the rear vehicle.At the same time,the chain plate machine fails frequently,and the resistance during pushing is large,resulting in slow progress of the working face and great safety risks.According to the actual geological conditions of 832 working face,a new technology of coal caving at high level is adopted,that is,by means of the telescopic beam at the front end of the contraction support,the top coal can fall with the mining,after coal caving,the support should be restored in time and the coal shield should be protected by the coal shield,the roof is supported by timely falling of the gangue after the frame to ensure that the initial supporting force of the support meets the requirements.The process not only has high resource recovery rate,simple transportation system and low equipment failure rate,At the same time,in order to strengthen the safety management,the corresponding safety risk monitoring and management technical means are established to ensure the safe and efficient mining of the working face.