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1·The technique of primary drilling and blasting is an effective way to solve the problem of crushing, caving and transportation.

该方法的初采钻爆技术是解决顶煤破碎与顺利放出的有效途径之一。

2·The primary and secondary dry crushing and associated dry screening systems are designed and sized to operate 6000 hours per year or 68.5 percent of total time.

初级和次级破碎和配套的干筛系统的设计和规模确定，是依据每年运行6000小时或总时间的68.5%。