Deep Hole Blasting In Open Differential Time Research On The Influence Of The Blasting Fragmentation

At present,deep hole blasting is still the most important technical means in open-pit mining.In recent years,due to the fine control blasting technology of strengthening and promotion,more and more high to the requirement of blasting quality and production cost,and the blasting fragmentation size is an important factor to reflect the blasting quality and production cost.To reduce the rate of rock block after blasting and the large size,improve the blasting quality,reduced the production cost,ore in this paper,combined with the high accuracy differential control blasting technology "project,in purple mountain gold mine for test site,using theoretical analysis,numerical simulation and field test of combining research methods,explore the open differential between time and deep hole blasting hole row between the influence law of millisecond time of blasting fragmentation,by optimizing the hole between the differential between differential time,time,in order to realize the lower rate of rock block after blasting and the large size of the target.According to carry out experimental study on the test purpose.First,summarizes the development course of millisecond blasting technology at home and abroad,this paper introduces the deep hole blasting in open a reasonable differential time half experience and half theory calculation formula and experience value,according to the experience and the characteristics of the theoretical formula and experience values,for deep hole blasting in open differential between the time of the initial test values for the hole between 28 ms,50 ms.Second,with the help of finite element analysis software ANSYS/ls-dyna,hole between the differential time of16 ms respectively,19 ms,22 ms,25 ms,28 ms,31 ms and row between the differential time of 35 ms respectively,40 ms,45 ms,50 ms,55 ms,60 ms to carry on the numerical simulation,and monitoring of adverse break the average of the maximum effective stress.Get,is not easy to broken the average of the maximum effective stress with the hole or between the increase of differential time between two presents first the change trend of decrease then increase,and 19 ms when differential between the hole,the differential between two time of 40 ms,bad broken maximum37.83 MPa,the average of the maximum effective stress for the whole of the rock broken.Finally,in the purple mountain gold copper opencast stope 24 different set of rows between differential blasting experiments,through analyzing the results of treatment,sum up the size of rock blasting fragmentation distribution,as well as the degree of large size with differential between rows and the changes of time and experimental conditions,the differential between the hole time of 19 ms,differential between two time of 40 ms ? 45 ms,rate of rock block after blasting and the large size achieves lower end,largely improve the blasting effect.In this paper show that the differential time of blasting fragmentation has very important influence,and determine the time differential between different rows and blasting fragmentation distribution,rock block rate and the dimension of the large degree of relationship.To improve the blasting effect,reduce the mining cost and promote the development of high precision millisecond controlled blasting technology is of great significance.