Strip mine step deep hole blasting method

Abstract

The invention discloses a deep hole blasting method for a strip mine step, relates to the technical field of blasting engineering, and aims to solve the problems that an existing strip mine step blasting method is easy to cause excessive large blocks on a slope surface and on the front section of the step, so that the excavation difficulty and the transportation potential safety hazard are increased. The method comprises the steps that an inclined first main blast hole and a vertical second main blast hole are drilled in the end, close to the slope surface, of a step to be blasted; a first auxiliary hole crossed with the first main blast hole is drilled in the slope surface, and a second auxiliary hole is formed beside the first main blast hole of the step; charging each blast hole with explosives; all the blast holes are connected into a detonating network through detonating lines; detonating through an exploder; wherein the first main blast hole and the second main blast hole can be distributed in a quincunx shape, the second main blast hole is vertical, and each main blast hole comprises a filling section and a charging section. According to the method, the auxiliary holes are formed to solve the problem of insufficient explosion stress of the slope and the step front section, and the explosion effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of blasting engineering, in particular to a deep hole blasting method for open-pit mine steps. Background Art

[0002] The open-pit mine step slope refers to the inclined surface of the step during the open-pit mine step mining process. It is a rock slope with a certain inclination angle formed by blasting, excavation and other operations during the mining process. This slope connects the bottom of the previous step and the top of the next step, and is an important part of the spatial form of open-pit mining. For example, in a large metal open-pit mine, the step height may be 15 meters, and the step slope slopes upward from the bottom of the step to form a stable rock slope structure.

[0003] After the blasting is completed, the existing open-pit mine step blasting method often finds that there are too many large blocks on the slope surface and the front section of the open-pit mine step. The excessive large blocks on the slope surface and the front section of the step (i.e. the part close to the slope surface) make the excavation work of the excavation equipment (such as the electric shovel) difficult and also increase the safety hazards in the transportation process. Summary of the invention

[0004] The object of the present invention is to provide a deep hole blasting method for open pit mine steps to solve the problems existing in the above-mentioned prior art and improve the blasting effect of the slope and the front section of the steps.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a method for deep hole blasting of open pit benches, comprising the following steps:

[0007] S1. Drilling a plurality of rows of inclined first main gun holes at one end of the step to be blasted close to the slope surface, wherein the angle between the first main gun holes and the vertical plane is an inclined angle, and drilling second main gun holes on the step to be blasted, wherein any of the second main gun holes is farther away from the slope surface than any of the first main gun holes;

[0008] S2, drilling a plurality of first auxiliary holes on the slope surface, wherein the first auxiliary holes are arranged in a cross pattern with the first main gun holes; and setting a plurality of second auxiliary holes beside a row of the first main gun holes on the step that is closest to the slope surface;

[0009] S3, charging all the first main gun holes, the second main gun holes, the first auxiliary holes and the second auxiliary holes;

[0010] S4, connecting all the first main gun holes, the second main gun holes, the first auxiliary holes and the second auxiliary holes with detonating wires to form a complete detonating network;

[0011] S5. Detonating the entire detonation network by means of a detonator.

[0012] Preferably, all of the first main gun holes and all of the second main gun holes are distributed in a plum blossom shape.

[0013] Preferably, the second main gun hole is arranged vertically.

[0014] Preferably, the first main gun hole includes a first stuffing section and a first charging section, and the second main gun hole includes a second stuffing section and a second charging section.

[0015] Preferably, all of the second auxiliary holes are located on a side of a row of the first main gun holes closest to the slope surface and away from the slope surface.

[0016] Preferably, the bottom end of the first main gun hole is closer to the slope surface than the top end of the first main gun hole.

[0017] Preferably, the first auxiliary hole is perpendicular to the slope surface.

[0018] Preferably, the second auxiliary hole is perpendicular to the top surface of the step.

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

[0020] The open-pit mine step deep hole blasting method of the present invention compensates for the problem of insufficient explosion stress on the slope surface and the front section of the step by setting a first auxiliary hole on the slope surface and a second auxiliary hole on the front section of the step, thereby improving the blasting effect of the slope surface and the front section of the step.

[0021] Furthermore, the first auxiliary hole on the step slope helps the front row of blast holes to overcome the clamping effect of the rock bottom, thereby solving the problem of large blocks in the front section of the step; the second auxiliary hole in the front section of the step is located between the first main blast hole and the second main blast hole on the step, thereby solving the problem of large blasting blocks caused by insufficient stress on the upper part of the step.

[0022] Furthermore, by setting the first main gun hole at an angle and making the bottom end of the first main gun hole closer to the slope than the top end of the first main gun hole, the minimum resistance line of the step slope can be reduced, and the blasting energy can be more concentrated, thereby generating greater destructive power in a smaller area, better exerting the role of the explosives in the first main gun hole, and improving the blasting effect of the step slope.

[0023] Furthermore, at least two rows of first main gun holes can be set according to actual needs, and the first main gun holes farther away from the slope have smaller inclination angles. The first main gun holes are all arranged obliquely. The setting of at least two rows of first main gun holes is to improve the chassis resistance line and improve the uniformity of chassis resistance line distribution, so that the chassis resistance lines between any adjacent main gun holes (including the first main gun hole and the second main gun hole) are relatively small and uniform. The uniform arrangement of the chassis resistance line makes the fragments after blasting more uniform, reduces the generation of large pieces and flying stones, facilitates subsequent excavation and transportation, and improves work efficiency; the drilling angle is gradually vertical, combined with the uniformly arranged resistance line, it can reduce the uneven damage caused by stress concentration, avoid local over-explosion or under-explosion, and ensure the stability and controllability of the blasting.

[0024] Furthermore, the first auxiliary hole and the first main gun hole are arranged in a staggered manner, which can enhance the stress at the bottom angle of the front section of the step, reduce the influence of the clamping effect of the bottom of the rock, and thus improve the rock crushing effect.

[0025] Furthermore, in practical applications, the charge conditions of the first auxiliary hole and the second auxiliary hole are designed according to the geological rock mass conditions. Specifically, for hard rock, using both the detonating charge and the auxiliary hole filled with explosives can increase the blasting energy and improve the rock crushing effect. For soft rock, using only the auxiliary hole of the detonating charge can reduce unnecessary energy consumption and allocate resources more effectively, thereby improving blasting efficiency and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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 will be briefly introduced below. Obviously, the drawings described below are only 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.

[0027] Figure 1 It is a cross-sectional view of the arrangement of blastholes in the open-pit mine bench deep hole blasting method of the present invention;

[0028] Figure 2 It is a blasthole arrangement diagram on a step in the open-pit mine step deep hole blasting method of the present invention;

[0029] In the figure: 1, step; 2, slope; 3, first main gun hole; 301, first filling section; 302, first charging section; 4, second main gun hole; 401, second filling section; 402, second charging section; 5, first auxiliary hole; 6, second auxiliary hole. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The object of the present invention is to provide a deep hole blasting method for open pit mine steps to solve the problems existing in the above-mentioned prior art and improve the blasting effect of the slope and the front section of the steps.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] like Figure 1 to Figure 2 As shown, this embodiment provides a method for deep hole blasting of open pit benches, comprising the following steps:

[0034] S1, drilling a row of first main gun holes 3 on one end of the step 1 to be blasted close to the slope 2, and drilling second main gun holes 4 on the step 1 to be blasted; the first main gun holes 3 are arranged obliquely;

[0035] S2, drilling a plurality of first auxiliary holes 5 on the slope 2, the first auxiliary holes 5 and the first main gun holes 3 being arranged in a cross pattern; and setting a plurality of second auxiliary holes 6 on the side of the step 1 located at the first main gun holes 3;

[0036] S3, charging all the first main gun holes 3, the second main gun holes 4, the first auxiliary holes 5 and the second auxiliary holes 6;

[0037] S4, connect all the first main gun holes 3, the second main gun holes 4, the first auxiliary holes 5 and the second auxiliary holes 6 with detonating wires to form a complete detonating network;

[0038] S5. Detonate the entire detonation network through the detonator.

[0039] Since the stress waves generated after the explosion of the first main gun hole 3 and the second main gun hole 4 will have a canceling effect, a stress-free zone and a stress-reduced zone will be formed when the stress waves are superimposed, and the explosion of the first auxiliary hole 5 and the second auxiliary hole 6 can well compensate for the problem of insufficient stress in the stress-free zone and the stress-reduced zone; specifically, the first auxiliary hole 5 arranged on the slope surface 2 helps the front row of gun holes to overcome the clamping effect of the rock bottom, so as to solve the problem of large blocks in the front section of the step 1; the second auxiliary hole 6 in the front section of the step 1 is located between the first main gun hole 3 and the second main gun hole 4 on the step 1, so as to solve the problem of large blasting blocks caused by insufficient stress in the upper part of the step 1.

[0040] In this embodiment, all the first main gun holes 3 and all the second main gun holes 4 are distributed in a plum blossom shape, and the second main gun holes 4 are vertically arranged; the first main gun holes 3 include a first filling section 301 and a first charging section 302, and the second main gun holes 4 include a second filling section 401 and a second charging section 402; all the second auxiliary holes 6 are located on the side of the first main gun holes 3 away from the slope 2; the bottom end of the first main gun holes 3 is closer to the slope 2 than the top end of the first main gun holes 3, which can reduce the minimum resistance line of the slope 2, make the blasting energy more concentrated, thereby generating greater destructive power in a smaller area, better play the role of the explosives in the first main gun holes 3, and improve the blasting effect of the slope 2 in the step 1; the first auxiliary hole 5 is perpendicular to the slope 2, and the second auxiliary hole 6 is perpendicular to the top surface of the step 1.

[0041] In addition, in practical applications, the charge conditions of the first auxiliary hole 5 and the second auxiliary hole 6 need to be designed according to the geological rock mass conditions. Specifically, for hard rock, using both the detonating charge and the auxiliary holes filled with explosives can increase the blasting energy and improve the rock crushing effect. For soft rock, using only the auxiliary holes of the detonating charge can reduce unnecessary energy consumption and allocate resources more effectively, thereby improving blasting efficiency and economic benefits.

[0042] It is worth noting that, although only one row of first main gun holes 3 is provided in the present embodiment, in actual application, several rows of first main gun holes 3 can be provided according to actual needs, the angle between the first main gun holes 3 and the vertical plane is an inclination angle, and any second main gun hole 4 is farther away from the slope surface 2 than any first main gun hole 3; and the second auxiliary hole 6 is located on the side of the first main gun holes 3 in the row closest to the slope surface 2, which is farther away from the slope surface 2; all the first main gun holes 3 in the same row are at the same distance from the slope surface 2, and the inclination angles of all the first main gun holes 3 in the same row are equal, and in any two rows of first main gun holes 3, the inclination angle of the row of first main gun holes 3 closer to the slope surface 2 is greater than the inclination angle of the other row of first main gun holes 3. In practical applications, technicians should determine the number of rows of the first main gun holes 3 based on the uniformity of the chassis resistance line distribution and the actual construction complexity; the setting of at least two rows of the first main gun holes 3 is to improve the chassis resistance line and improve the uniformity of the chassis resistance line distribution, so that the chassis resistance lines between any adjacent main gun holes (including the first main gun hole 3 and the second main gun hole 4) are relatively small and uniform. The uniform arrangement of the chassis resistance line makes the fragments after blasting more uniform, reduces the generation of large pieces and flying stones, facilitates subsequent excavation and transportation, and improves work efficiency; the drilling angle is gradually vertical, combined with the uniformly arranged resistance line, which can reduce the uneven damage caused by stress concentration, avoid local over-explosion or under-explosion, and ensure the stability and controllability of the blasting.

[0043] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A deep hole blasting method for open pit benches, characterized in that: The following steps are involved: S1. Drilling a plurality of rows of inclined first main gun holes at one end of the step to be blasted close to the slope surface, wherein the angle between the first main gun holes and the vertical plane is an inclined angle, and drilling second main gun holes on the step to be blasted, wherein any of the second main gun holes is farther away from the slope surface than any of the first main gun holes; S2, drilling a plurality of first auxiliary holes on the slope surface, wherein the first auxiliary holes are arranged in a cross pattern with the first main gun holes; and setting a plurality of second auxiliary holes beside a row of the first main gun holes on the step that is closest to the slope surface; S3, charging all the first main gun holes, the second main gun holes, the first auxiliary holes and the second auxiliary holes; S4, connecting all the first main gun holes, the second main gun holes, the first auxiliary holes and the second auxiliary holes with detonating wires to form a complete detonating network; S5. Detonating the entire detonation network by means of a detonator.

2. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: All of the first main gun holes and all of the second main gun holes are distributed in a plum blossom shape.

3. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: The second main gun hole is arranged vertically.

4. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: The first main gun hole includes a first stuffing section and a first charging section, and the second main gun hole includes a second stuffing section and a second charging section.

5. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: All of the second auxiliary holes are located on a side of a row of the first main gun holes closest to the slope surface and away from the slope surface.

6. The open-pit mine bench deep hole blasting method according to claim 5, characterized in that: The bottom end of the first main gun hole is closer to the slope surface than the top end of the first main gun hole.

7. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: The first auxiliary hole is perpendicular to the slope surface.

8. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: The second auxiliary hole is perpendicular to the top surface of the step.

9. The open-pit mine bench deep hole blasting method according to claim 1, characterized in that: The distances between all the first main gun holes in the same row and the slope surface are equal, and the inclination angles of all the first main gun holes in the same row are equal.

10. The open-pit mine bench deep hole blasting method according to claim 9, characterized in that: In any two rows of the first main gun holes, the inclination angle of the row of the first main gun holes closer to the slope is greater than the inclination angle of the other row of the first main gun holes.

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