Blasting ignition method of fan-shaped medium-length hole

Abstract

The invention provides a blasting ignition method of a fan-shaped medium-length hole. The blasting ignition method comprises the steps that blast holes at the same row are divided into two sets, the deepest one third of blast holes located in the middle are a set A, and the rest of the blast holes located in the two sides are a set B; the blast holes of the set A are firstly ignited in the blasting process, and then the blast holes of the set B are ignited. The blast holes in the set A are sequentially provided with lower-section high-precision blasting caps at intervals of 25 milliseconds, the blast holes in the set B are sequentially provided with high-section high-precision blasting caps at intervals of 25 milliseconds, and meanwhile the time delay of 300-350 milliseconds is maintained between the maximal blasting cap section in the set A and the minimal blasting cap section in the set B. According to the blasting ignition method of the fan-shaped medium-length hole, energy released by explosive explosion is sufficiently utilized to break rocks and apply work, the ore rock fragmentation after blasting is improved, the ore recovery rate is increased, and meanwhile the secondary blasting harm is reduced.

Description

Technical field: [0001] The invention relates to a blasting initiation method for a fan-shaped medium and deep hole, which belongs to the technical field of underground mining. Background technique: [0002] Blasting in underground mining is a very important part of the entire mining process. On the one hand, it is necessary to ensure that the ore rock mass after blasting meets the design requirements, and to create a good foundation for the subsequent links of mining resources; on the other hand, it must be fully utilized The energy released by the explosive explosion is used to break the rock and do work to reduce secondary hazards, such as the destruction of underground facilities by shock waves and the damage to structures on the ground by seismic waves. In mines that use the pillarless sublevel caving method, the method of blasting the ore is the upward fan-shaped medium-depth hole millisecond squeeze blasting. Its characteristic is: when the blasting is carried out, conside...

AI Technical Summary

Problems solved by technology

The disadvantage of adopting this method of detonation is that the deeper holes in the middle of one group are not segmented, and the amount of explosives in one section of blasting is still relatively large, which is easy to produce over-extrusion after blasting, which is unfavorable for ore drawing, and at the same time The underground shock wave generated by the blasting and the seismic wave transmitted to the ground have a great negative impact; the blasting of the same row is only divided into two stages, and there are few opportunities for extrusion during the blasting process, and the ore lumpiness after blasting varies greatly

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