北洺河地下矿山大块控制劈裂爆破技术研究

北洺河地下铁矿巷道内遗留大块难以高效处理，利用面对称金属聚能罩实现对大块的快速劈裂，在铁矿巷道内对大块进行了6组爆破试验，对比0、1倍炸高，2倍炸高时的块度分布、平均块度和爆破形态， 研究了聚能装药参数中炸高、炸药单耗对大块破碎效果的影响。结果表明：无炸高时，碎块主要分布在大尺寸60 ~ 80 cm区间内；随着炸高的增加，碎块主要分布在中尺寸20 ~ 60 cm区间内；有利的炸高使大尺寸区 间内的平均块度降低10%左右、中尺寸区间内平均块度增加30% ~ 45%；同等炸高条件下，炸药单耗的微幅变化对区间内平均块度影响较小；金属射流形态影响着爆破形态，随着炸高的提升，大块二次破碎程度提高， 碎块由轴向对称向交叉对称转变，利用聚能爆破可有效实现对大块的控制劈裂。

Study on the Controlled Splitting Blasting Technology of Large Blocks in Underground Mine

The large blocks left in the roadway of Beiminghe underground iron mine are difficult to efficiently handle.The surface symmetrical metal energy-concentrating cover is used to realize the rapid splitting of the large blocks. Six sets of blasting tests are performed on the large blocks in the iron mine roadway. Compare the fragmentation distribution,average fragmentation and blasting morphology when the explosion height is 0,1 explosion height and 2 explosion height,to study the influence of the explosion height and the unit consumption of the explosive on the crushing effect of large block in the parameters of the shaped charge. The results show that when there is no height,the fragments are mainly distributed in the interval of large size 60~80 cm;with the increase of the height of explosion,the fragments are mainly distributed in the interval of medium size 20~60 cm;the favorable height of the explosion makes the large size The average block size in the interval is reduced by about 10%,and the average block size increase in the medium-sized interval is about 30%~45%;under the same explosive height condition,the slight change of explosive unit consumption has little effect on the average value in the interval;the blasting shape is influenced by metal jet morphology,with the increase of the blast height,the degree of secondary crushing of large pieces increases,and the fragments change from axial symmetry to cross-symmetrical. The application of energy-accumulating blasting can effectively realize the controlled splitting of large pieces.