Underground coal mine deep hole blasting method for weakening hard rock in whole deep hole range at one time

Abstract

The invention discloses an underground coal mine deep hole blasting method for weakening hard rock in the whole deep hole range at a time, and relates to the technical field of engineering blasting, according to the distribution condition of the underground coal mine hard rock, holes are drilled to obtain charging hole groups and empty hole groups, and the charging hole groups and the empty hole groups are alternately arranged in the height direction; the charging holes in the charging hole group and the empty holes in the empty hole group are staggered in the horizontal direction; detonating cords are laid in all the charging holes and connected with electronic detonators, the charging holes are filled with explosives, and all the charging holes are blocked through hole sealing materials; filling explosives into hole opening sections, corresponding to the plugging lengths of the charging holes, in the empty holes to form explosive sections, installing electronic detonators in one ends, close to the hole openings, of the explosive sections, and plugging the hole openings with hole sealing materials; leg wires of the electronic detonators are connected to a blasting line in parallel, and detonation is completed. The hard rock in the whole deep hole range can be weakened at a time, time and cost are saved, risks caused by multiple times of detonation are reduced, and the hard rock passing efficiency of the coal mining machine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering blasting, and particularly to a deep-hole blasting method for underground coal mines that can weaken hard rock in the entire deep-hole range at one time. Background Art

[0002] Deep-hole blasting in underground coal mines is different from that on the ground. In the "Coal Mine Safety Regulations", it is stipulated that in underground coal mine blasting, the plugging length should be greater than one-third of the hole length. Therefore, when deep-hole blasting is carried out underground, the plugging length is generally relatively long, and the weakening effect of hard rock in the plugging section is poor. The existing Chinese patents "A Deep-Hole Blasting Method for Underground Coal Mines" (Publication No. CN114234748A), "A Large-Diameter Deep-Hole Blasting Method Suitable for Coal Mines Passing Through Subsidence Columns" (Publication No. CN114279282A), and "A Super Deep-Hole Blasting Method" (Publication No. CN111207640A) do not consider the weakening of hard rock in the plugging section. In order to achieve the weakening effect of the entire blast hole, it is necessary to drill blast holes about 2 m deep in the hard rock of the plugging section later and complete the blasting layer by layer until the weakening work of all the hard rock in the plugging section is completed. This work not only wastes time and money but also brings negative risks and impacts due to multiple detonations, resulting in low efficiency of the shearer passing through hard rock. Summary of the Invention

[0003] The purpose of the present invention is to provide a deep-hole blasting method for underground coal mines that can weaken hard rock in the entire deep-hole range at one time, so as to solve the problems existing in the above-mentioned prior art, weaken the hard rock in the entire deep-hole range at one time, save time and cost, reduce the risks caused by multiple detonations, and improve the efficiency of the shearer passing through hard rock.

[0004] To achieve the above purpose, the present invention provides the following solutions:

[0005] The present invention provides a deep-hole blasting method for underground coal mines that can weaken hard rock in the entire deep-hole range at one time, including:

[0006] According to the distribution of hard rock in underground coal mines, charging holes and empty holes are drilled respectively. The charging hole group includes a plurality of charging holes arranged at intervals in the horizontal direction, and the empty hole group includes a plurality of empty holes arranged at intervals in the horizontal direction. The charging hole group and the empty hole group are alternately arranged in the height direction, and the charging holes in the charging hole group are horizontally misaligned with the empty holes in the empty hole group;

[0007] Lay detonating cords in each charging hole and connect the detonating cords to electronic detonators, lead out the leg wires of the electronic detonators from the charging holes, fill explosives in the charging holes, and plug each charging hole with plugging materials;

[0008] In each of the empty holes, in the hole section corresponding to the plugging length of the charging hole, first fill the orifice section with plugging material to form an inner plugging section, then fill with explosive to form an explosive section, install an electronic detonator inside one end of the explosive section close to the orifice, lead out the leg wires of the electronic detonator from the empty hole, and then plug each orifice with plugging material;

[0009] Parallelly connect the leg wires of each of the electronic detonators to the blasting main wire, and use a detonator to check the detonation network to complete the detonation work.

[0010] In one embodiment, the charging holes in each charging hole group are arranged at equal intervals, and the empty holes in each empty hole group are arranged at equal intervals.

[0011] In one embodiment, the distance between two adjacent charging holes in the charging hole group is equal to the distance between two adjacent empty holes in the empty hole group.

[0012] In one embodiment, the length of the empty hole is not less than the length of the charging hole, and the diameter of the empty hole is not less than the diameter of the charging hole.

[0013] In one embodiment, each charging hole group is arranged at equal intervals in the height direction, and the empty hole group is located at the middle position in the height direction between two adjacent charging hole groups.

[0014] In one embodiment, the horizontal distance between the empty hole and the two adjacent charging holes on its two sides is equal.

[0015] In one embodiment, the axis of the charging hole is parallel to the axis of the empty hole.

[0016] In one embodiment, the length of the explosive section in the empty hole is one-half to two-thirds of the plugging length of the charging hole.

[0017] In one embodiment, the length of the detonating cord in the charging hole is equal to the charging length.

[0018] In one embodiment, the direction of the shaped charge cavity of the electronic detonator faces the bottom of the hole.

[0019] The present invention has achieved the following technical effects compared with the prior art:

[0020] The present invention provides a deep-hole blasting method for underground coal mines that weakens hard rock in the entire deep-hole range at one time. In the hard rock drilling in underground coal mines, a charging hole group and an empty hole group are obtained. The charging hole group and the empty hole group are alternately arranged in the height direction, and the charging holes in the charging hole group and the empty holes in the empty hole group are offset in the horizontal direction. Explosives are loaded in the hole mouth section of the empty hole corresponding to the plugging length of the charging hole. The design of the empty hole can not only create a free surface for the charging hole, but also provide a swelling space for the broken rock of the charging hole, improving the blasting effect of the charging hole. By loading explosives in the hole mouth section of the empty hole corresponding to the plugging length of the charging hole, together with the charging section in the charging hole, it is possible to complete the blasting of the hard rock in the entire deep-hole range at the same time, achieving the purpose of weakening the hard rock in the entire deep-hole range at one time, and only requiring one detonation, which not only saves time and cost, but also greatly reduces the risks caused by multiple detonations, thereby improving the efficiency of the shearer passing through hard rock and ultimately realizing the high-yield and high-efficiency production of coal mines. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of the arrangement of charging holes and empty holes in an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of the charging of charging holes and empty holes in an embodiment of the present invention.

[0024] In the figure: 1 - hard rock, 2 - first charging hole, 3 - second charging hole, 4 - third charging hole, 5 - fourth charging hole, 6 - fifth charging hole, 7 - sixth charging hole, 8 - seventh charging hole, 9 - eighth charging hole, 10 - ninth charging hole, 11 - tenth charging hole, 12 - eleventh charging hole, 13 - twelfth charging hole, 14 - thirteenth charging hole, 15 - fourteenth charging hole, 16 - fifteenth charging hole, 17 - sixteenth charging hole, 18 - first empty hole, 19 - second empty hole, 20 - third empty hole, 21 - fourth empty hole, 22 - fifth empty hole, 23 - sixth empty hole, 24 - seventh empty hole, 25 - detonating cord, 26 - type Ⅰ coal mine permitted digital electronic detonator, 27 - leg wire of detonator, 28 - type Ⅲ coal mine permitted powdered emulsion explosive, 29 - loess, 30 - type Ⅲ coal mine permitted digital electronic detonator, 31 - blasting main line, 32 - detonator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The present invention provides a deep-hole blasting method for underground coal mines that weakens hard rock in the entire deep-hole range at one time, including:

[0026] According to the distribution of hard rock in the coal mine underground, charging holes and empty holes are drilled respectively. The charging hole group includes a plurality of charging holes arranged at intervals in the horizontal direction. The empty hole group includes a plurality of empty holes arranged at intervals in the horizontal direction. The charging hole group and the empty hole group are alternately arranged in the height direction. The charging holes in the charging hole group and the empty holes in the empty hole group are arranged in a horizontal dislocation.

[0027] Detonating cords are laid in each of the charging holes and the detonating cords are connected to electronic detonators. The leg wires of the electronic detonators are led out of the charging holes. Explosives are loaded into the charging holes. Each of the charging holes is blocked with a plugging material.

[0028] In the hole mouth section corresponding to the blocking length of the charging hole in each of the empty holes, a plugging material is first loaded to form an inner blocking section, and then explosives are loaded to form an explosive section. An electronic detonator is installed inside one end of the explosive section close to the hole mouth. The leg wires of the electronic detonator are led out of the empty hole, and then each hole mouth is blocked with a plugging material.

[0029] The leg wires of each of the electronic detonators are connected in parallel to the blasting main wire, and the initiation network is checked with an initiator to complete the initiation work.

[0030] In the present invention, by drilling charging holes and empty holes in the hard rock in the coal mine underground, the charging hole group and the empty hole group are alternately arranged in the height direction, and the charging holes in the charging hole group and the empty holes in the empty hole group are arranged in a horizontal dislocation. Explosives are loaded in the hole mouth section corresponding to the blocking length of the charging hole in the empty hole. The design of the empty hole can not only create a free surface for the charging hole, but also provide a swelling space for the broken rock in the charging hole, improving the blasting effect of the charging hole. By loading explosives in the hole mouth section corresponding to the blocking length of the charging hole in the empty hole, together with the explosive section in the charging hole, the hard rock in the entire deep hole range can be blasted simultaneously, achieving the purpose of weakening the hard rock in the entire deep hole range at one time, and only one initiation is required, which not only saves time and cost, but also greatly reduces the risks caused by multiple initiations, thereby improving the efficiency of the shearer passing through the hard rock and finally realizing the high-yield and high-efficiency production of the coal mine.

[0031] As an embodiment of the present invention, the charging holes in the charging hole group are arranged at equal intervals, and the empty holes in the empty hole group are arranged at equal intervals. The equal interval arrangement can make the explosion stress waves of adjacent charging holes fully superimpose during the propagation process, forming a continuous energy coverage area. In addition, the explosion stress wave reflects at the empty hole to form a tensile wave, and the tensile strength of the rock is much smaller than the compressive strength. Therefore, the damage range of the rock is increased.

[0032] As an embodiment of the present invention, the distance between two adjacent charging holes in the charging hole group is equal to the distance between two adjacent empty holes in the empty hole group. The same distance can ensure the same stress superposition effect in the middle of each blast hole, thus ensuring the uniformity of the blasting effect.

[0033] As an embodiment of the present invention, the length of the empty hole is not less than the length of the charging hole, and preferably the length of the empty hole is equal to the length of the charging hole. The empty hole can not only reflect the stress wave to form a tensile sound wave to expand the rock fragmentation range, but also form a swelling space for the fragmentation of the rock in the charging hole to further expand the blasting fragmentation area.

[0034] As an embodiment of the present invention, the diameter of the empty hole is not less than the diameter of the charging hole, and preferably the diameter of the empty hole is equal to the diameter of the charging hole. The larger the diameter of the empty hole, the better the effect, but the drilling equipment in the coal mine is limited and the construction difficulty is relatively large. For the convenience of construction, generally, the diameter of the charging hole is selected to be equal to the diameter of the empty hole.

[0035] As an embodiment of the present invention, each charging hole group is arranged at equal intervals in the height direction, and the empty hole group is located at the middle position in the height direction between two adjacent charging hole groups. According to the blasting funnel theory, when the blast holes are arranged in a five-flower hole pattern, the blasting effect is relatively the best.

[0036] As an embodiment of the present invention, the horizontal distance between the empty hole and the two adjacent charging holes on its two sides is equal. Based on the symmetry principle, under the condition of the same distance, the influence of the empty hole on the surrounding charging holes is consistent, thus avoiding the uncertainty of the blasting effect caused by the change of the blasting boundary conditions of the charging holes.

[0037] As an embodiment of the present invention, the charging hole and the empty hole are parallel to each other to ensure that the charging holes and the empty holes do not penetrate each other.

[0038] As an embodiment of the present invention, the length of the explosive section in the empty hole is one-half to two-thirds of the plugging length of the charging hole, and preferably the length of the explosive section in the empty hole is half of the plugging length of the charging hole, so as to improve the weakening effect of hard rock blasting in the plugging section.

[0039] As an embodiment of the present invention, the length of the detonating cord in the charging hole is equal to the charging length to ensure that all the explosives loaded in the charging hole can be detonated.

[0040] As an embodiment of the present invention, the direction of the shaped charge cavity of the electronic detonator faces the bottom of the hole. The shaped charge cavity converges the detonator explosion products into a high-speed and high-pressure shaped charge flow through its conical cavity. When the shaped charge cavity faces the bottom of the hole, the shaped charge flow directly acts on the bottom explosive or detonating cord of the hole, reducing energy loss and ensuring sufficient detonation of the explosive.

[0041] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0042] As Figure 1 - Figure 2 shown, this embodiment provides a deep-hole blasting method for coal mines underground to weaken the hard rock in the entire deep-hole range at one time, including:

[0043] Step 1: Determine the length, diameter, spacing between rows and columns, and number of blast holes according to the distribution of hard rock 1 in the coal mine underground, where the blast holes include charge holes and empty holes;

[0044] In Step 1, the length of hard rock 1 is 10 m, the width is 3 m, and the depth is 30 m. The length of the blast holes (charge holes and empty holes) is 30 m, the diameter is 75 mm, and the number is 23. Among them, there are 16 charge holes, namely the first charge hole 2, the second charge hole 3, the third charge hole 4, the fourth charge hole 5, the fifth charge hole 6, the sixth charge hole 7, the seventh charge hole 8, the eighth charge hole 9, the ninth charge hole 10, the tenth charge hole 11, the eleventh charge hole 12, the twelfth charge hole 13, the thirteenth charge hole 14, the fourteenth charge hole 15, the fifteenth charge hole 16, and the sixteenth charge hole 17. The first charge hole 2 to the eighth charge hole 9 form the second row of charge holes, and the ninth charge hole 10 to the sixteenth charge hole 17 form the first row of charge holes. There are 7 empty holes, arranged in rows, namely the first empty hole 18, the second empty hole 19, the third empty hole 20, the fourth empty hole 21, the fifth empty hole 22, the sixth empty hole 23, and the seventh empty hole 24. The row spacing of the charge holes is 80 cm, the spacing is 1.2 m, the first row of charge holes is 1.1 m from the bottom, and the second row of charge holes is 1.1 m from the top. The empty holes are 1.5 m from the bottom, the row spacing between the charge holes and the empty holes is 40 cm, and the spacing of the empty holes is also 1.2 m;

[0045] Step 2: Make marks on the working face according to the blast hole parameters in Step 1, and start drilling. The charge holes and the empty holes are kept parallel, and all blast holes cannot penetrate each other;

[0046] Step 3: Wash the residual rock debris in the blast holes with water, drain the water in each blast hole after washing, and record the blast hole positions, integrity, and on-site lengths to provide a basis for the determination of the later charge holes and the charge lengths;

[0047] Step 4: Determine the charge length and the charge length of the empty holes according to the charge hole length, and then determine the length of the detonating cord 25 in the charge holes; the length of the detonating cord 25 in the charge holes is equal to the charge length, and no detonating cord is laid in the empty holes;

[0048] Step 5: Connect two digital electronic detonators 26 permitted for use in Section I coal mines to 1m in front of one end of the detonating cord 25, and insert the other end of the detonating cord 25 into the bottom of the charging hole, wherein the energy-gathering hole of the digital electronic detonator 26 permitted for Section I coal mines faces the bottom of the hole, and lead the detonator leg wire 27 out of the blast hole; in addition, sieve the third-level coal mine permitted powdered emulsion explosive 28 and pour it into the charge loader, and use the charge loader to load the explosive into the charging hole;

[0049] Step 6: Repeat step 5 until all charging holes are charged, and then use loess 29 to block each charging hole;

[0050] Step 7: Charge each empty hole, the charging length of the empty hole is half of the plugging length of the charging hole; first, use loess 29 to plug the 2m empty hole, then start charging, install 2 digital electronic detonators 30 permitted for Section III coal mines 1m in front of the charging end, the energy-gathering hole direction of the digital electronic detonator 30 permitted for Section III coal mines is toward the bottom of the hole, lead the detonator foot line 27 out of the blasthole, and then use loess 29 to plug the opening of the empty hole;

[0051] In step 7, the plugging length of the charge hole is 10m, so the length of the empty hole to be acted on is 10m; first, 2m of the empty hole mouth is blocked with loess 29, then 4m of charge is charged, and then 2 digital electronic detonators 30 permitted for use in Section III coal mines are installed, and then 1m of charge is charged, and finally the remaining 3m of the hole mouth is blocked with loess 29;

[0052] Step 8: Connect all the detonator pins 27 in the blast hole in parallel to the blasting line 31, use the detonator 32 to check the detonation network, and complete the detonation work at one time.

[0053] The invention provides a method for deep hole blasting in coal mines that can weaken the hard rock in the entire deep hole range at one time. The method utilizes a method of charging charges in charging holes and empty holes respectively to achieve one-time weakening of the hard rock in the entire deep hole range. Only one detonation is required, which not only saves time and cost, but also greatly reduces the risks caused by multiple detonations, thereby improving the efficiency of coal mining machines in passing through hard rocks, and ultimately achieving high-yield and high-efficiency production in coal mines. The method has important engineering practical significance.

[0054] 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 underground coal mines that weakens hard rock in the entire deep-hole range at one time, characterized in that, Including: According to the distribution of hard rock in the coal mine underground, charging holes and empty holes are drilled respectively. The charging hole group includes a plurality of charging holes arranged at intervals in sequence along the horizontal direction. The empty hole group includes a plurality of empty holes arranged at intervals in sequence along the horizontal direction. The charging hole group and the empty hole group are arranged alternately in the height direction. The charging holes in the charging hole group and the empty holes in the empty hole group are arranged in a horizontal dislocation; Detonating cords are laid in each of the charging holes and the detonating cords are connected to electronic detonators. The leg wires of the electronic detonators are led out of the charging holes. Explosives are loaded into the charging holes, and each of the charging holes is blocked with a hole-sealing material; In each of the empty holes, in the hole section corresponding to the blocking length of the charging hole at the orifice, a hole-sealing material is first loaded to form an inner blocking section, and then explosives are loaded to form an explosive section. An electronic detonator is installed inside one end of the explosive section close to the orifice. The leg wires of the electronic detonator are led out of the empty hole, and then each orifice is blocked with a hole-sealing material; The leg wires of each of the electronic detonators are connected in parallel to the blasting main wire, and the initiation network is checked with an initiator to complete the initiation work.

2. The method for deep-hole blasting in underground coal mines for weakening the entire hard rock in the deep-hole range at one time according to claim 1, wherein: The charging holes in the charging hole group are arranged at equal intervals, and the empty holes in the empty hole group are arranged at equal intervals.

3. The deep-hole blasting method for underground coal mines that weakens the entire hard rock in the deep-hole range at one time according to claim 2, characterized in that: The distance between two adjacent charging holes in the charging hole group is equal to the distance between two adjacent empty holes in the empty hole group.

4. The method for deep-hole blasting in underground coal mines for weakening the entire hard rock in the deep-hole range at one time according to claim 1, wherein: The length of the empty hole is not less than the length of the charging hole, and the diameter of the empty hole is not less than the diameter of the charging hole.

5. The method for deep-hole blasting in coal mines for weakening the hard rock in the entire deep-hole range at one time according to claim 1, wherein: Each of the charging hole groups is arranged at equal intervals in the height direction, and the empty hole group is located at the middle position in the height direction between two adjacent charging hole groups.

6. The deep-hole blasting method for underground coal mines that weakens the entire hard rock in the deep-hole range at one time according to claim 5, characterized in that: The horizontal distance between the empty hole and the two adjacent charging holes on its two sides is equal.

7. The method for deep-hole blasting in coal mines for weakening the hard rock in the entire deep-hole range at one time according to claim 1, characterized in that: The axis of the charging hole is parallel to the axis of the empty hole.

8. The method for deep-hole blasting in a coal mine for weakening the entire hard rock in the deep-hole range at one time according to claim 1, characterized in that: The length of the explosive section in the empty hole is one-half to two-thirds of the blocking length of the charging hole.

9. The method for deep-hole blasting in underground coal mines for weakening the entire hard rock in the deep-hole range at one time according to claim 1, characterized in that: The length of the detonating cord in the charging hole is equal to the charging length.

10. The method for deep-hole blasting in a coal mine for weakening the entire hard rock in a deep-hole range at one time according to claim 1, characterized in that: The shaped charge cavity direction of the electronic detonator faces the bottom of the hole.

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