大柳塔矿活鸡兔井12煤下分层放顶煤工作面放煤效果研究  

Top-coal caving effect in the lower slice of 12~#coal seam in Huojitu well Daliuta Mine

作　　者：高士岗 GAO Shi-gang(Daliuta Coal Mine,CHN Energy Shendong Coal Group,Shenmu 719315,China;College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China)

机构地区：[1]神东煤炭集团大柳塔煤矿,陕西神木719315 [2]西安科技大学能源学院,陕西西安710054

出　　处：《煤炭工程》2020年第10期56-60,共5页Coal Engineering

摘　　要：为了解决活鸡兔井复合区特厚硬煤上分层综采、下分层综放工作面在回采过程中存在工作面机尾段放煤效果差、采空区遗煤多的问题,根据复合区开采煤层的地质条件,对影响放顶煤工作面冒放性的主要因素进行分析,对工作面机尾段顶煤分别采取高压水力预裂、高压气体深孔预裂进行预先弱化的技术。通过在12下206综放工作面实施表明:高压水力预裂技术,预裂之后放煤效果有所提升,但效果不佳,顶煤回收率只有50%~70%左右。高压气体深孔预裂新技术可对顶煤实施预裂弱化,产生大量裂隙,增强顶煤的冒放性,顶煤回收率可达到85%左右,同时也可以释放上覆煤岩应力,防止回采过程中机尾段顶板突然垮落造成支架压死。固体产气预裂技术的应用,可以预先弱化坚硬顶煤,增强顶煤的冒放性,降低块煤率,提高采出率,同时减弱周期来压的显现强度,为放顶煤的安全生产提供有效的保障。Aiming at the insufficient coal caving and problems caused by the residual coal in goaf,during mining the extrathick hard coal at the machine-tail in in composite mining district of Huojitu Mine,which uses fully mechanized mining in the upper slice and top-coal caving in the lower slice,the main factors affecting coal caving property are analyzed according to the geological conditions,and the top coal at both sides of working face is pre-weakened using high-pressure hydraulic pre-fracturing and high-pressure gas deep-hole pre-cracking.The implementation effect in the No.206 working face in the 12 lower coal seam show that,the coal caving is improved while not satisfying after high-pressure hydraulic pre-fracturing,the top coal recovery rate is 50%~70%.The new technology of high-pressure gas deep hole pre-cracking can weaken the top coal,produce a large number of cracks,and enhance the top coal caving property,which raises the top coal recovery rate to about 85%,meanwhile release stress of the overlying rock and coal,and prevent the roof from sudden collapsing and crushing the support at the tail section during mining.Weakening top-coal with solid gas pre-cracking technology can enhance the top-coal caving property,reduce the large-lump rate,improve the recovery rate,and abate the behavior of periodic weighting,thus guarantee the safe production of top-coal caving.

关 键 词：分层开采 放顶煤 水力压裂 固体产气预裂 放煤效果 

分 类 号：TD823.49[矿业工程—煤矿开采]