【作者】 何荣兴；

【导师】 任凤玉；

【作者基本信息】 东北大学 ， 采矿工程， 2008， 硕士

【摘要】 北洺河铁矿为接触交代矽卡岩型磁铁矿床,应用无底柱分段崩落法开采,现已进入东部厚大矿体开采,沿用分段高度15m、进路间距18m、崩矿步距1.7-3.7m、最小抵抗线1.7-2.0m的爆破参数和孔底同段起爆顺序,实际生产中出现炮孔堵塞和变形、大块率高、隔墙和悬顶事故时有发生等问题,严重影响矿石回采指标与生产效率。本文在系统地归纳与分析无底柱分段崩落法扇形炮孔破岩机理的基础上,对起爆顺序、爆破参数与布孔形式等问题进行了研究。基于冲击波与爆生气体共同破岩的原理以及国内文献介绍的微差起爆实现数据,论述了起爆方向与起爆顺序对破岩效果的影响,确定了孔底微差起爆方式。根据实验得出的放出体与残留体、的形态,以及在现场标定的出矿过程的混岩数据,推断出崩落体形态,进而通过几何作图法得出,现有采场结构情况下,崩矿步距1.7m所对应的放出体形态与崩落体、残留体的总体形态符合较差,是造成此时废石混入早和混入率高的主要原因；崩矿步距3.4m与和3.7m时对比,放出体中下部崩落矿石的增大率高于放出体上部覆盖层废石的增大率,由此得出,在现行的采场结构参数下,崩矿步距3.7m比崩矿步距3.4m优越。取用3.7m的崩矿步距,设计了一次微差爆破两排炮孔、前排抵抗线2.0m、共布置9个炮孔,后排抵抗线1.7m、共布置8个炮孔的爆破网络。改进后的爆破网络将孔底距由原来的2.6m增加到3.6m,每排节省1-2个炮孔,每步距可节省20.6m长的炮孔,可节省炸药92.7kg。改进方案已经提交矿山,并已得到认可,正在实施中。更多还原

【Abstract】 Beiminghe iron ore mine is contact metasomatic skarn polymeatal deposit, its mining method is non-pillar sublevel caving. The thick ore bodies of the mine have been mining. The sublevel height is fifteen meter, the drift interval is eighteen meter, the caving space is one point seven to three point seven,the ignition sequence is bottom priming in same stage. There are several problems in produce such as the borehole was blocked or deformation, the high big rock rate, the partition and goal suspended ceiling appeared which impact recovery index and mining efficiency seriously.This paper systematic study of initiation sequence, blasting parameters and deter-mining hole intervals based on the blasting mechanism of fan-patterned holes. The paper discussed that the initiation sequence and the explosive azimuth had effect on rock breaking efficiency and determined the model of hole-bottom millisecond initiation according to the mechanism of shock wave and detonation gas rock breaking together and the data in domestic literature. According to the shapes of draw body and residual body and the date of waste in-ore rate calibrated in ore removal, it deduced the shape of caved ore body. It proved that the shapes of draw body, residual body and caved ore body when the caving space is 1.7 meter coincided poor with each other in existing structure of the stope which is the main reason of sooner and higher waste in-ore rate. Comparing the condition when the caving space are 3.4 meter and 3.7 meter,it found that the ore increasing rate in the lower part of draw body is higher than the waste increasing rate in the upper of the draw body,so the caving space of 3.7 meter is superior to the caving space of 3.4 meter in existing structure of the stope. The paper designs the blasting network that it blasted two rows boreholes, the front row arrangements nine boreholes whose resistance line is two meter. The back row arrangements eight boreholes whose resistance line is one point seven meter. The hole-bottom spacing has increased from two point six to three point six, and the borehole has decreased by one ore two in improved blasting network, which can save 92.7 kilogram explosive and 20.6 meter boreholes in each caving space.The improvement scheme has submitted to the mine, and has been reviewed and implementing.更多还原