Method of high bench hole interior millisecond delay blasting of open pit mine

Abstract

The invention provides a method of high bench hole interior millisecond delay blasting of an open pit mine. The method comprises the following steps that firstly, a blasting hole is drilled in the bench face; secondly, the blasting hole formed in the first step is filled with explosives, a grain is formed, the total length of the grain is 53%-60% the depth of the blasting hole, and detonation points are set at different height positions of the grain; and thirdly, millisecond delay interval detonation is carried out at the different detonation points, and the millisecond delay interval time t=L / v; specifically, L is the total length of the grain, the unit is the meter; t is the millisecond delay interval time, and the unit is the millisecond; and v is the detonation velocity, and the unit is the meter per millisecond. The method of high bench hole interior millisecond delay blasting of the open pit mine makes full use of the characteristic that the length of the grain in the high benchblasting hole is large, the hole interior millisecond delay interval time, the interval charging structure, the detonation point positions and the detonation sequence are reasonably set according to amethod of millisecond delay interval blasting in the blasting hole, the blasting effect is improved, and the blasting vibration harmful effect is reduced.

Description

technical field [0001] The invention belongs to the technical field of mining engineering, and in particular relates to a micro-difference blasting method in a high-step hole in an open-pit mine. Background technique [0002] With the increase in the demand for resources in modern society and the advancement of mining equipment and technology, the scale of open-pit mining has further increased, and the scale of blasting has also expanded, requiring further improvement in the efficiency of open-pit mining. Step blasting refers to the rock blasting method that is propelled in the form of steps, that is, the operation of drilling and blasting on the stepped excavation surface in the open air. For a long time, large-scale open-pit mines in my country have mostly used a step height of 12-15m. High-step blasting refers to step heights above 18m. High-step blasting increases the length of columnar charges, which is one of the important means to improve the blasting scale and mining...

AI Technical Summary

Problems solved by technology

[0003] The current open-pit mining method is affected by inertial thinking and the theoretical lag of blasting technology, and is limited by the low precision of traditional detonators. The usual way is to use common detonators to set one or two detonation points in the blast hole to detonate simultaneously to realize the detonation of explosives in the blast hole. As disclosed in the Chinese patent document CN108412495A, a method of step blasting in an open pit , drilling pre-splitting holes, main blasting holes and blasting holes on the steps, blasting the pre-splitting holes first, and adopting differential blasting between the remaining holes. The pre-splitting surface is formed by the pre-splitting holes to improve the blasting effect, but the holes are blasted at the same time Detonation can not produce the superposition effect of the blasting stress field in the high-step blasthole, and the time when the blasting stress wave does not act on the rock mass is relatively short

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