露天矿穿孔
露天矿穿孔-
通过实例，对中小型露天矿穿孔参数确定进行论述。
The paper gives discussion about the middle and small scale strip mine perforation parameter through example .
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从1958年研究新型穿孔设备，到七十年代才开始更新露天矿的穿孔设备。
Development of new drilling equipment began in 1958 , and in the seventies they began to replace older open pit drilling equipment .