Research on the control technology of medium-length hole blasting fragmentation in underground mine

The scalloped medium-length hole blasting mining method used in Dahongshan Copper Mine accounted for more than 61%of the total amount of mining,but the large boulder yield restricted the intensity of ore supply for mines,and the average boulder yield was as high as 22.7%.In order to develop the mine production efficiency,the circular medium-length hole blasting technology was proposed and field tests were carried out.The test results showed that circular medium-length hole blasting mining can reduce the average boulder yield to 10.3%.Compared with the traditional scalloped medium-length hole blasting mining,the average boulder yield was decreased by 12.4%.The daily yield of ore for the panel on duty was increased by 152.29 t,and the growth rate was 51.1%.The new technology can reduce the time for the handling of boulder and the consumption of explosives and detonators for recrushing,and increase the efficiency of mining while reduce the mining cost,which has received good blasting effects.

Numerical simulation of blasting effect with divided charge structure

This paper numerically simulates the stress development and generates a three-dimensional model of the medium-length hole blasting in infinite rock mass for continuous charge and divided charge in blasting by using the large-scale nonlinear dynamic analysis software LS-DYNA and the elastic-plastic model ~*MAT_PLASTIC_KINEMATIC and JWO-EOS.The differences of the decreasing rate in Von Mises effective stress of blasting,element effective stress peak of free surface,bore wall stress and acceleration are investigated.It is shown that divided charge could greatly improve the blasting effect by engineering blasting practice.

阶段回采与顶板支护中深孔一孔两用试验研究

针对谦比西铜矿预控顶上向中深孔空场嗣后充填法的采矿工艺,利用Sandvik DS421锚索台车,提出了一种“一孔两用”的预护顶技术方案,可不施工支护巷,直接在凿岩巷施工护顶锚索,安装好锚索后锚索孔作为回采中深孔使用。首先详细介绍了技术方案的设计思路,然后根据相关手册对扇形中深孔孔网及爆破参数进行计算与验证,最后介绍了该技术方案的现场施工,讨论了“一孔两用”的后续改进方向。结果表明:通过自制锚索套管装置,可实现矿体内自由端锚索的分离回收利用,实现了仅支护末端6.5 m的预期目的;将锚索孔并入扇形中深孔统一孔网参数设计,锚索孔排面与常规中深孔排距0.5 m,锚索孔孔底距为1.6 m;有间隔锚索孔的中深孔孔底距3.2 m,其余中深孔的孔底距为2.2 m,炸药单耗0.45 kg/m^(3);以谦比西铜矿采场参数为例,每个采场可节约采切工程量1672 m^(3)、管缝锚杆330根、金属锚网496 m^(2),减少了锚索使用量221 m、中深孔850 m,具有良好工程效益与应用价值。

地下矿山中深孔落矿爆破块度控制技术研究

扇形中深孔爆破的落矿方式在大红山铜矿中的应用占总采矿量的61%以上,但大块产出率较高严重制约着矿山供矿强度,平均大块率高达22.7%。为了降低大块率,实现矿山生产的高效发展,提出采用环形中深孔爆破落矿工艺并进行了现场试验,试验结果表明环形中深孔爆破落矿可使平均大块率降低至10.3%,与传统扇形中深孔落矿相比较,平均大块率降低了12.4%,使盘区当班日供矿量增加152.29 t,增长率为51.1%;减少了处理大块所耽误的时间和二次破碎的炸药与雷管的消耗,在提高出矿效率的同时,降低了落矿成本,取得了良好的爆破效果。

圆型隧洞超硬岩爆破进尺与掏槽方式探讨

本文介绍了圆型隧洞施工中,在超硬围岩条件下通过不同的钻爆试验,采用不同的掏槽方式,产生不同的爆破进尺效果,从而确定选择合理的掏槽方式和爆破参数,以达到最佳进尺确保进度的要求。

圆型隧洞超硬岩爆破进尺与掏槽方式探讨

介绍了圆型隧洞施工中,在超硬围岩条件下通过不同的钻爆试验,采用不同的掏槽方式,产生不同的爆破进尺效果,从而确定选择合理的掏槽方式和爆破参数,以达到最佳进尺确保进度的要求。