公开(公告)号：US3917347A

公开(公告)日：1975-11-04

申请号：US49969874

申请日：1974-08-22

申请人： JANSSEN ALBERT T ,  ATLANTIC RICHFIELD CO

发明人： JANSSEN ALBERT T ,  ATLANTIC RICHFIELD COMPANY

IPC分类号： E21C41/24 ,  F42D99/00 ,  E21C41/10 ,  F42D7/00

CPC分类号： E21C41/24

摘要： A subterranean ore deposit, such as oil shale, is undercut to form a cavity of predetermined void volume. A specific block of the deposit overlaying this cavity is designated together with an intermediate level thereof. From a suitable working space, explosively charged primary blasting holes are drilled substantially horizontally into the block so as to provide a uniform explosive charge distribution therein below the intermediate level. At least one secondary blasting hole is driven downwardly into the block from the surface of the earth or from an upper mining level and explosively charged above the intermediate level. The primary and secondary explosives are detonated in upwardly progressing timed sequence. This results in expansion of the overlaying block into the cavity and fragmentation thereof in a cone-shaped configuration above the intermediate level.

摘要翻译： 诸如油页岩的地下矿床被切削以形成预定空隙体积的空腔。 覆盖该空腔的沉积物的特定块与其中间水平一起被指定。 从合适的工作空间中，爆炸性充电的初级爆破孔基本上水平地钻入该块中，以便在中间水平面之下提供均匀的炸药电荷分布。 至少一个二次爆破孔从地球表面向下驱动到块体中或从上部采矿层向下驱动，并在中间水平以上爆炸充电。 主要和次要爆炸物以向上的时间顺序引爆。 这导致覆盖块在空腔中的膨胀和其在中间水平以上的锥形构造中的分裂。