摘要
在上薄下厚极近距离煤层联合开采条件下,上位薄煤层开采对两煤层间岩层造成不同程度的破坏,同时其直接顶和老顶垮冒后成为破碎介质和块裂介质,因而下位厚煤层综放开采顶煤顶板为破坏程度不同、破断块度大小不一的不同介质属性岩层,将对顶煤的放落回收产生很大影响。因此,采用二维离散元PFC数值模拟软件对极近距离煤层联合开采在不同破断块度条件下的顶煤放出过程及煤矸流动规律进行了模拟分析。研究表明,下位煤层的顶板块度与顶煤块度差异较大时,放煤过程中易出现窜矸等现象,导致顶煤回收率较低;优化确定了放煤工艺为一刀一放上行顺序放煤。研究成果在现场进行了应用,实测分析了放煤工艺及回收率,取得了良好的技术效果。
In the combined mining of ultra-close multiple-seams with thin upper seam and thick lower seam,the mining of thin upper seam leads to damage of different degress in the interlayer.Meanwhile,the caved immediate roof and main roof become crushing medium and block medium.As a result,the roof of the thick lower seam in the fully mechanized caving process is turned into layers consisting of parts with different medium properties,in terms of damage severity and rock size,which significantly affects the caving and recovery of top coal.Therefore,in this paper,a simulation analysis of top coal caving and roof rock movement law under different fracture conditions was carried out with a two dimensional discrete element PFC numerical simulation software program.The results have revealed that roof rock channels into the top coal in the coal caving process in the presence of a considerable difference in the lump size of roof rock and top coal of the lower seam,which results in low recovery ratio;after optimization,the one-cut-one-caving-upward caving pattern is determined to be top coal caving parameter.The research results have been applied in the field,and the coal caving process and recovery rate have been measured,and good technical results have been obtained.
作者
张宁波
刘长友
陈宝宝
朱传奇
周劲锋
ZHANG Ningbo;LIU Changyou;CHEN Baobao;ZHU Chuanqi;ZHOU Jinfeng(School of Mines,Key Laboratory of Deep Coal Resource Mining,Ministry of Education of China,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology,Huainan,Anhui 232001,China;National Engineering Research Center for Coal Gas Control,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2021年第5期911-918,共8页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52174137,51704275)
中国博士后科学基金项目(2020T130697,2019M661994)
深部煤矿采动响应与灾害防控国家重点实验室开放基金项目(SKLMRDPC20KF13)。
关键词
近距离煤层
下位厚煤层
联合开采
放煤工艺参数
ultra-close multiple-seams
thick lower seam
combined mining
top coal caving parameters
