采矿实践表明，露天矿爆破矿岩的平均（加权平均）块度，对有用矿物和废石的开采成本有重大的影响。破碎过细，穿孔爆破费用会显著增加，而破碎过租，回采、装载、运输和排土（推置）费用又会显著增加。如果在设计时知道最佳平均块度，则能合理地确定钻孔网度和装药量，从而保 Mining practice has shown that the average (weighted average) extent of blasting ore in open pit mines can have a significant impact on the cost of extracting useful minerals and waste rock. Broken too small, perforated blasting costs will be significantly increased, and broken rent, mining, loading, transportation and dumping (push) costs will increase significantly. If you know the best average block at design time, you can reasonably determine the mesh size and charge,