Pre-splitting blasting method

Abstract

The invention relates to a presplitting blasting method. The presplitting blasting method comprises the steps that S1, bamboo chips corresponding to presplitting holes in length are prepared; s2, a pre-splitting detonating assembly is prepared; pre-splitting detonating assemblies are sequentially fixed to the bamboo chips in the length direction of the bamboo chips; the pre-splitting detonating assembly comprises a pre-splitting cartridge bag, an air spacer and a digital electronic detonator. S3, after the pre-splitting explosive bag and the air spacer are fixed according to design requirements, a pre-splitting explosive string with bamboo chips is formed, the pre-splitting explosive string is put into the pre-splitting hole, and after the pre-splitting explosive string is put into the pre-splitting hole, the air spacer is expanded to form an air spacing cavity; s4, network setting: laying a double-strand copper core wire on one side of the pre-splitting hole, and connecting a leg wire of the digital electronic detonator to the double-strand copper core wire to form a blasting network; and S5, a digital electronic detonator is directly used for detonating the presplitting cartridge bag. According to the method, the influence of shock waves on the sensitivity of the explosive can be effectively reduced, the pre-splitting cost can be effectively reduced on the premise of ensuring the blasting quality, and the labor efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of open-pit blasting, in particular to a pre-splitting blasting method. Background Art

[0002] Pre-splitting blasting in open-pit mines is to bundle rock emulsion explosive strings onto detonating cords, which are then detonated by detonating cords to achieve pre-splitting and reduce the damage to the retained rock mass caused by blasting in the main blasting area.

[0003] At present, with the supply of detonating cord in the past two years outstripping the demand and the price increasing exponentially, the original pre-splitting blasting scheme is no longer optimal in terms of production and economic benefits. Therefore, it is urgent to design a new pre-splitting blasting scheme to achieve the goal of meeting the fast pace of production and achieving the best economic benefits. Summary of the invention

[0004] In view of the above problems, the object of the present invention is to provide a pre-splitting blasting method, which uses digital electronic detonators to directly detonate instead of the existing method of using detonating cords for pre-splitting blasting, which can effectively reduce the pre-splitting cost and improve labor efficiency while ensuring the blasting quality.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A pre-splitting blasting method proposed by the present invention comprises the following steps:

[0007] S1, preparing bamboo pieces corresponding to the length of the pre-split holes;

[0008] S2, preparing a pre-splitting detonating assembly; fixing the pre-splitting detonating assembly on the bamboo piece in sequence along the length direction of the bamboo piece;

[0009] The pre-splitting detonating assembly comprises a pre-splitting charge, an air spacer and a digital electronic detonator; the air spacer is fixed above the pre-splitting charge at a certain distance; the digital electronic detonator is fixed inside the pre-splitting charge; the pre-splitting charge is fixed on the bamboo piece;

[0010] S3, after the pre-splitting charge package and the air spacer are fixed according to the design requirements, a pre-splitting charge string with bamboo pieces is formed, the pre-splitting charge string is lowered into the pre-splitting hole, and after the pre-splitting hole is loaded, the air spacer is expanded to form an air spacer cavity;

[0011] S4. Network setting: Lay a double-strand copper core wire on one side of the pre-crack hole, connect the digital electronic detonator foot wire to the double-strand copper core wire to form a blasting network;

[0012] S5. Directly use digital electronic detonators to detonate the pre-splitting charge.

[0013] Furthermore, the pre-splitting medicine package is a rock emulsion medicine roll.

[0014] Furthermore, the number of the pre-splitting detonating assemblies is set according to the length of the pre-splitting hole.

[0015] Furthermore, the delay time of the digital electronic detonators is the same, and is set to detonate 145ms-155ms ahead of the main blasting area.

[0016] Furthermore, in step S2, the digital electronic detonator is inserted from the top of the pre-splitting charge until the detonator body is completely immersed in the pre-splitting charge, and then fixed by means of adhesive tape.

[0017] Furthermore, the pre-splitting hole is an inclined hole with an angle of 46° or 56°, and adopts an axially segmented and radially uncoupled charge structure.

[0018] Furthermore, the air spacer is a pull-type air spacer.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The present invention uses a digital electronic detonator to directly detonate the pre-splitting charge, which can effectively reduce the impact of shock waves on the sensitivity of explosives compared with the traditional method of using detonating cord to detonate the pre-splitting charge;

[0021] 2. The present invention adopts an axial segmented interval charging and radially uncoupled charging structure, while the traditional blasting method adopts a radially uncoupled axial continuous charging structure;

[0022] 3. The present invention uses a spacer to form an air spacer cavity, which can increase the action time of the detonation wave in the blast hole, weaken the influence of the shock wave on the sensitivity of the explosive, and better play the role of penetrating into seams and preventing vibration.

[0023] 4. The present invention adopts an axial segmented charge structure. Compared with the axial continuous charge structure adopted in the traditional technology, the present invention requires fewer bundled medicine rolls and has higher labor efficiency. In addition, the present invention ties the medicine rolls to bamboo pieces, which have a certain strength and are easier to lower into the pre-splitting hole. Due to the presence of the bamboo pieces, it also plays a certain protective role in preserving the rock mass. The traditional blasting method is to directly tie the pre-splitting charge to the detonating cord, which lacks strength (the pre-splitting hole is an inclined hole with an angle of 46° and 50°).

[0024] 5. The pre-splitting blasting cost of the present invention is greatly reduced compared with the traditional method. Calculated based on a 100-meter pre-splitting line, the single-hole pre-splitting blasting cost of the present invention is reduced by about 164 yuan compared with the traditional technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a blasting structure of an embodiment of a pre-splitting blasting method proposed by the present invention.

[0026] Among them, the figure markings are: 1-pre-splitting charge; 2-air spacer cavity; 3-digital electronic detonator; 4-pre-splitting hole; 5-air spacer; 6-filling section; 7-bamboo piece. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] A pre-splitting blasting method proposed by the present invention has the following specific implementation process:

[0029] S1. Prepare bamboo pieces 7 corresponding to the length of the pre-splitting holes 4. In this embodiment, the pre-splitting holes 4 are inclined holes with an angle of 46° or 56° and a diameter of 115 mm, and adopt an axially segmented and radially uncoupled charging structure.

[0030] S2, prepare pre-splitting detonating components; fix the pre-splitting detonating components on the bamboo piece 7 in sequence along the length direction of the bamboo piece; the number of the pre-splitting detonating components is set according to the length of the pre-splitting hole. In this embodiment, three groups of pre-splitting detonating components are provided; the three groups of pre-splitting detonating components are fixed on the bamboo piece 7 in sequence and connected end to end;

[0031] The pre-splitting detonating assembly comprises a pre-splitting charge 1, a lifting air spacer 5 and a digital electronic detonator 3; the pre-splitting charge 1 is a rock emulsion charge, which is fixed and tied to a bamboo piece 7 by an adhesive tape; the air spacer 5 is fixed above the pre-splitting charge 1 at a certain distance; the digital electronic detonator 3 is inserted from the top of the pre-splitting charge 1 until the detonator body is completely immersed in the pre-splitting charge 1, and then fixed by an adhesive tape;

[0032] The diameter of the bottom pre-splitting package 1 in the pre-splitting hole 4 is 110 mm, which matches the inner diameter of the pre-splitting hole 4. First, the gap between the medicine roll and the pre-splitting hole 4 is reduced as much as possible to reduce the gap effect; second, the medicine loading at the bottom of the pre-splitting hole 4 is strengthened to overcome the clamping effect at the bottom; note that the packaging at the connection of the medicine roll should be removed.

[0033] S3, after the pre-splitting charge 1 and the lifting air spacer 5 in each group of pre-splitting detonating components are fixed according to the design requirements, a pre-splitting charge string with bamboo pieces 7 is formed, and the pre-splitting charge string is lowered into the pre-splitting hole 4, and a filling section 6 is arranged between the top of the pre-splitting hole 4 and the top lifting air spacer 5; after the pre-splitting charge string is loaded into the pre-splitting hole 4, each lifting air spacer 5 is expanded to form an air spacer cavity 2 between each pre-splitting charge 1;

[0034] Due to the adoption of the axial segmented interval charging structure, compared with the traditional pre-splitting continuous charging structure, the number of bundled medicine rolls is less and the labor efficiency is higher; due to the inherent strength of the bamboo strips 7, it is easier to lower, and it is not easy to cause blockage, waste holes, etc., and the blasting effect is more ideal.

[0035] The lifting air spacers 5 of the bottom section and the middle section can be expanded with the help of the resistance of the pre-splitting charge 1 on the top; the lifting air spacer 5 of the top section can be expanded with the help of the gun rod.

[0036] The purpose of setting the air spacer cavity 2 is, firstly, that the air shock wave generated by the explosion of the explosive will be refracted and weakened after encountering the spacer, so as to avoid the air compression wave generated by the air shock wave reducing the sensitivity of the explosive; secondly, to prolong the time for the detonation wave generated by the explosion of the explosive to act in the pre-crack hole 4, so as to better play the role of penetrating into cracks and preventing vibration.

[0037] S4. Network setting: Lay a double-strand copper core wire on one side of the pre-crack hole 4, connect the 3-pin wire of the digital electronic detonator to the double-strand copper core wire to form a blasting network.

[0038] S5. Directly use digital electronic detonators to detonate the pre-splitting charge; wherein the delay time of the digital electronic detonators is the same (except 0ms), and is set to detonate 145ms-155ms ahead of the main blasting area, which has a higher detonation accuracy and is safer. The reason why it is not set to 0ms is that 0ms is the initial state, which is unstable and has a certain probability of refusal to explode.

[0039] As shown in Table 1, the pre-splitting blasting method proposed in the present invention significantly reduces the blasting cost compared with the traditional blasting method.

[0040] Table 1 Comparison of pre-splitting blasting prices with new technology and traditional technology

[0041]

[0042]

[0043] The present invention uses a digital electronic detonator 3 to directly detonate the pre-splitting charge 1, while the existing blasting technology is to manufacture the digital electronic detonator and the detonator together into a detonating charge, and then the detonating charge detonates the pre-splitting charge. The present invention directly uses the digital electronic detonator 3 instead of the detonator, which can reduce the impact of the shock wave on the sensitivity of the explosive. In addition, the bottom of the present invention uses a 110 rock emulsion roll, which has a detonator sensitivity and can be directly detonated using the detonator. The existing blasting technology is to first load a certain amount of industrial emulsion explosives into the hole, and then place the rock emulsion roll in the industrial emulsified oil to form a coupled charge structure. Since the industrial emulsion explosive itself does not have the detonator sensitivity, it must be detonated using a detonator. The entire construction process is relatively complicated and the labor efficiency is low. In addition, there is a method of directly using a 90 rock emulsion roll at the bottom without coupling the charge and using a detonator to detonate, which is greatly affected by the gap effect and the probability of the explosive refusing to explode increases.

[0044] The pre-splitting blasting method proposed in the present invention has been tried out in the Nanfen open-pit iron mine of Benxi Steel, and has achieved good blasting effects, wherein the half-wall porosity can reach more than 90% in hard rock areas (mainly amphibolite), more than 80% in medium-hard rock (mixed granite), and 30% in soft rock areas (mainly quartzite) of silica mountain; the slope rate deviation is less than ±2°; the slope surface is smooth, and the slope surface flatness (concave-convex difference) is less than ±150mm, both of which are better than the industry standard.

[0045] Matters not described in detail in the present invention are all known technologies.

[0046] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A pre-splitting blasting method, characterized in that: The method comprises the following steps: S1, preparing bamboo pieces corresponding to the length of the pre-split holes; S2, preparing a pre-splitting detonating assembly; fixing the pre-splitting detonating assembly on the bamboo piece in sequence along the length direction of the bamboo piece; The pre-splitting detonating assembly comprises a pre-splitting charge, an air spacer and a digital electronic detonator; the air spacer is fixed above the pre-splitting charge at a certain distance; the digital electronic detonator is fixed inside the pre-splitting charge; the pre-splitting charge is fixed on the bamboo piece; S3, after the pre-splitting charge package and the air spacer are fixed according to the design requirements, a pre-splitting charge string with bamboo pieces is formed, the pre-splitting charge string is lowered into the pre-splitting hole, and after the pre-splitting hole is loaded, the air spacer is expanded to form an air spacer cavity; S4. Network setting: Lay a double-strand copper core wire on one side of the pre-crack hole, connect the digital electronic detonator foot wire to the double-strand copper core wire to form a blasting network; S5. Directly use digital electronic detonators to detonate the pre-splitting charge.

2. A pre-splitting blasting method according to claim 1, characterized in that: The pre-splitting medicine package is a rock emulsion medicine roll.

3. A pre-splitting blasting method according to claim 1, characterized in that: The number of the pre-splitting detonation components is set according to the length of the pre-splitting hole.

4. A pre-splitting blasting method according to claim 1, characterized in that: The delay time of the digital electronic detonators is the same, and is set to detonate 145ms-155ms ahead of the main blasting area.

5. A pre-splitting blasting method according to claim 1, characterized in that: In step S2, the digital electronic detonator is inserted from the top of the pre-splitting charge until the detonator body is completely immersed in the pre-splitting charge, and then fixed by adhesive tape.

6. A pre-splitting blasting method according to claim 1, characterized in that: The pre-splitting hole is an inclined hole with an angle of 46° or 56°, and adopts an axial segmented and radially uncoupled charge structure.

7. A pre-splitting blasting method according to claim 1, characterized in that: The air spacer is a pull-type air spacer.

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