含水露天矿加强水封塞爆破技术研究

在露天矿山爆破中，台阶上部是大块产生的主要部位，一直未能得到很好的解决，当炮孔含水时这一问题尤为显著。鉴于目前很多露天矿山大多炮孔为水孔的情况，为了减少爆破时台阶上部产生的大块率，通过对高冲击下水介质特性的分析以及在和尚桥铁矿的现场试验，提出了大孔径加强水封塞爆破装药结构，即在炸药与填塞物之间留取一定长度的水柱，在水柱与填塞物之间设置加强封塞药包。经过对加强水封爆破技术的理论分析、计算及现场工程试验，结果表明大孔径加强水封塞爆破技术可改善台阶上部岩石爆破后的块度组成，大幅减少大块率，有效提高炸药有效能量利用率，降低爆破后二次破碎成本，提高矿山生产效率。同时，该技术可以有效降低爆破粉尘，创造良好的作业环境，在同类相似矿山推广应用，可以取得较好的经济效益和社会效益。

Stiffened Water Sealing Blasting Technology in the Hydrated Open-pit Mine

Large fragments are chiefly generated at the upside parts of bench in open-pit bench blasting，and this problem isn′t well solved all the time，especially in the hydrous holes.In view of the situation that hydrous holes exist in most of open-pit mines，and in order to reduce rate of block at upside parts of bench in blasting，the charge structure of stiffened water sealing for large diameter holes is presented by analyzing the characteristics of water medium under high-impact and on-site test in Heshangqiao iron ore.That is，a certain length of water column is retained between tamping and explosive，and the stiffened tamping ammunition is arranged between tamping and water column.The theoretical analysis，calculation and on-site tests of the stiffened tamping blasting showed that this blasting technology effectively improved the block composition at upside parts of bench after blasting，reduced the rate of block and increased the utilization efficiency of explosive.By this method，the costs of secondary crushing after blasting is reduced，and the mine productivity is improved as well.Meanwhile，this technique can effectively decrease the blasting dust and create a favorable working environment for staff.Its spreading and application in similar mine achieved good economic and social benefit.