Numerical and theoretical investigations of the effect of the gangue-coal density ratio on the drawing mechanism in longwall top-coal caving
Jinwang Zhang1
Dongliang Cheng2
Yinchao Yang3
Weijie Wei2
Zhaolong Li4
Zhengyang Song5
1.State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology-Beijing,Beijing 100083,China;State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology,Xuzhou 221116,China;Coal Industry Engineering Research Center of Top-Coal Caving Mining,Beijing 100083,China2.State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology-Beijing,Beijing 100083,China;Coal Industry Engineering Research Center of Top-Coal Caving Mining,Beijing 100083,China3.Jizhong Energy Group,Xingtai 054099,China4.Yichun Luming Mining Co.,Ltd.,Yichun 152500,China5.Coal Industry Engineering Research Center of Top-Coal Caving Mining,Beijing 100083,China;Department of Civil Engineering,School of Civil and Resource Engineering,University of Science and Technology Beijing,Beijing 100083,China
摘要：Discrete element calculations of the top-coal drawing process for different gangue-coal density ratios were conducted to investigate the effect of the gangue-coal density ratio on the drawing mechanism in longwall top-coal caving.The effects were analyzed for the drawing body,the top-coal boundary,and the recovery of top coal.The results show that for increasing density ratio,the initial drawing body on the goaf side is farther away from the drawing support and its width and volume gradually increase.The upper part of the sickle-shaped drawing body extends near the initial drawing body with increasing density ratio in the normal cycling stage,and the distance from the drawing body to the initial drawing body is its maximum width.The larger the density ratio,the smaller the height of the top coal above the goaf at the end of the initial drawing process.The height of the top-coal boundary decreases with increasing density ratio,until it reaches a limit.In a normal cycle,due to hysteretic development,the top-coal boundary moves toward the goaf until the density ratio is approximately 2.0,which is consistent with the physical experiment results.Finally,increasing the advance length of the working face is beneficial for increasing the overall recovery of top coal.
机标关键词：mechanismdensitycavingdrawingeffectgangue-coalinvestigationslongwall
论文发表日期：2022-04-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：20( 147-166 )
英文信息