Blasting method for benches in open mining area

Abstract

The present invention relates to a blasting method for benches in an open mining area. At least three groups of holes, namely, pre-splitting holes, main blast holes and blast holes, are drilled vertically downward on a bench flat plate. Interval charging is carried out in the blast holes, and the explosive load is increased from top to bottom according to the need; interval charging is further carried in the pre-splitting holes, and the explosive load is decreased from top to bottom; and the main blast holes are fully charged. The pre-splitting holes are initiated first, the main blast holes and the blast holes are initiated after the pre-splitting holes are initiated for 50-120ms, and the interval time between the main blast holes and the blast holes is [delta]t in sequence. The effect that an idea bench slope is directly blasted out is achieved. According to the blasting method for the benches in the open mining area, vertical drilling is adopted, the construction is relatively simple, and the requirements on a drilling rig are not high; the charging procedure adopts interval charging, the blasting effect in each section can be effectively used to form an ideal bench slope angle,and the amount of rock stripping is reduced; and in terms of blasting time, the pre-cracking holes are initiated first to form a pre-splitting surface, differential blasting is used for remaining blast hole rows and between holes, and the best blasting effect is achieved by rational use of explosive energy rationally.

Description

technical field [0001] The invention relates to the field of blasting, in particular to a step blasting method in an open-pit stope. Background technique [0002] In the mining process of open-pit mines, the cost of stripping rocks is relatively large. The increase of the slope angle of the steps can effectively reduce the amount of rock stripping and increase economic benefits. Therefore, it is necessary to increase the slope angle of the steps as much as possible under the premise of ensuring the stability of the steps. [0003] The process of forming each step is mainly to punch holes, charge explosives, detonate explosives, and strip excess rock blocks. Choosing reasonable drilling, charging and detonation methods can achieve better blasting effects, form an ideal slope angle, reduce the amount of rock stripping in the later stage, and increase economic benefits. The charge structure currently used is mainly continuous charge, or interval charge according to the diffe...

AI Technical Summary

Problems solved by technology

However, during the formation of inclined drilling, the drilling machine not only has to bear the vertical downward force, but also resists the component force generated by the angle between the drilling machine and the vertical direction, so the stability of the drilling machine in the drilling process is poor. , the construction difficulty is increased, and the construction cost is also high

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