峨口铁矿北采场硐室大爆破安全控制技术

峨口铁矿为了稳定采矿生产能力 ,需要开发北采场 ,利用硐室大爆破剥离覆盖层。爆破分两次进行 ,每次药量控制在 40 0t以内 ,以减小爆破地震和空气冲击波对周围环境的影响。根据振动速度、飞石和冲击波安全距离的经验公式 ,计算出最大一响用药量和抵抗线的最大值 ;对药室的空间分布和层间距的选取做了精心设计 ;直接以前后排药室的最小水平距离作为中下层后排药室的最小抵抗线 ;此外 ,还采用了分集药包等手段 ,保证了爆破效果

SAFETY TECHNOLOGY FOR LARGE-SCALE CHAMBER BLASTING IN NORTHERN MINING AREA OF EKOU IRON OPENPIT

Ekou Iron Openpit needs to exploit the northern mining area and uses chamber blasting for the stripping of overburden,in order to stabilize mining production The chamber blasting is carried out at twice and the charge weight once is within 400 tons,so as to minimize the effect of blasting vibration and shockwave on surroundings The maximum one interval charge weight and the burden are calculated with empirical formulas for vibration velocity and the safety distances of flying rocks and shockwaves The space distribution of charged chambers and the selection of slice spacing are considered carefully The minimum horizontal distance between fore and post row charged chambers is directly used as the burden of post row charged chamber in mediate and bottom levels In addition,the technological measures such as sub concentration charges are taken,ensuring the blasting effect