A method for the construction of a plug in an upwardly directed blasthole in an underground mine

Abstract

The application discloses an underground mine upward blast hole plugging construction method, which comprises a blast hole charging pipe, a compressed air charging and pipe withdrawing step and a blast hole plugging step. The plugging assembly is compacted to make the upper and lower movable ends of the plugging assembly dislocated and mutually extruded in the blast hole to be clamped and tightly combined with the inner wall of the blast hole, thereby realizing blast hole plugging. The plugging assembly is tightly combined with the inner wall of the blast hole through clamping and filling of gaps, thereby effectively preventing powdery ammonium nitrate explosive from falling or returning from the hole, ensuring stable existence of the explosive in the hole, avoiding waste of the explosive and avoiding safety hazards caused by falling of the explosive. The method is convenient and efficient, reduces labor intensity, and is easy to obtain and low in cost. The plugging assembly can be selected according to the upward blast hole with different diameters, is suitable for blast holes with different specifications, and is clear in construction steps and simple in operation. The method does not need complex construction technology, can effectively reduce the work load of repeated charging, reduces labor intensity of operation personnel and improves blasting operation efficiency.

Description

Technical Field

[0001] This invention relates to the field of underground mine blasting construction technology, and in particular to a method for plugging upward blast holes in underground mines. Background Technology

[0002] In upward deep-hole blasting operations in underground mines, ensuring that the explosive does not fall back or drop is crucial for guaranteeing the quality, safety, and effectiveness of the blasting operation when using powdered ammonium nitrate explosives for upward-facing borehole loading. Because the borehole opening faces upwards and the explosive inside is subject to gravity, upward-facing boreholes are highly susceptible to explosive falling back and falling back. Inadequate sealing measures can directly affect the blasting effect and even lead to safety accidents.

[0003] Currently, the industry commonly suffers from improper operation and poor sealing effects when sealing upward blast holes. In most cases, the hole is not sealed at all, or simply plugged with paper scraps, failing to form an effective sealing structure. This crude sealing method causes powdered ammonium nitrate explosive to easily fall out of the hole, resulting in serious waste of explosives and requiring workers to reload, increasing repetitive workload and labor intensity. Furthermore, the fallen explosives may cause accidental ignition and explosions, seriously threatening the personal safety of underground workers and the mine's production order. In addition, improper sealing leads to explosive waste, increased mining costs, reduced blasting efficiency, impaired rock breaking, and increased difficulty in subsequent cleanup operations. Summary of the Invention

[0004] The main objective of this invention is to provide a method for sealing upward blast holes in underground mines, which aims to solve the problems of waste of explosives, repetitive work, high labor intensity and prominent safety hazards caused by the non-standard sealing of upward blast holes in existing methods.

[0005] To achieve the above objectives, this invention proposes a method for sealing upward blast holes in underground mines, comprising the following steps: S1. Loading and feeding pipe for blast hole: The operator feeds the blast hole pipe and detonating cord together into the bottom of the blast hole, ensuring that the end of the detonating cord reaches the preset position at the bottom of the hole and the end of the blast hole pipe is close to the bottom of the blast hole. S2. Compressed air delivery and tube withdrawal: After confirming that the delivery tube and detonating cord are in place, the mixed explosive is delivered into the borehole through a manual compressed air loading device. After filling, the delivery tube is withdrawn and delivery is stopped. S3. Hole plugging: After the charge is completed, immediately insert the plugging component into the hole until it reaches the charge surface; use a long gun barrel to insert into the hole and press the plugging component so that the upper and lower movable ends of the plugging component are misaligned and squeezed against each other in the hole, tightly fitting against the inner wall of the hole. The blocking assembly includes an upper movable block and a lower movable block. The opposing surfaces of the upper and lower movable blocks are complementary wedge-shaped surfaces. They are connected by fastening pins with a gap. When the upper movable block is pressed, the fastening pins deform, and the two opposing wedge-shaped surfaces squeeze each other. The upper and lower movable blocks move closer to the inner wall of the borehole. A flexible filling material is provided between the upper and lower movable blocks and the inner wall of the borehole.

[0006] Preferably, the following steps are also included: Blocking component processing: Take a pair of the upper movable blocks and the lower movable blocks, make their wedge-shaped surfaces face each other, and use the fastening pins to drive them into the upper movable blocks or the lower movable blocks, with the driving direction of the fastening pins perpendicular to the wedge-shaped surfaces; cover the periphery of the assembled blocking component with flexible filler material.

[0007] Preferably, the reserved gap ranges from 5 to 10 mm.

[0008] Preferably, the diameters of the upper movable block and the lower movable block are in the range of 50~55mm, and the overall length after combination is 200~220mm.

[0009] Preferably, the flexible filler material includes rice straw and thatch.

[0010] Preferably, before step S1, there is also a step of making explosive bags: pouring powdered ammonium nitrate explosive and diesel into a mixing container and stirring according to a preset ratio; after stirring, packing the evenly mixed explosive into a packaging bag.

[0011] Preferably, before step S1, the following steps are included: a comprehensive cleaning of the blasting operation site, removal of obstacles from the site, delineation of the charging warning zone, inspection of the air pressure of the manual air pressure charging device, and inspection and acceptance of the blast holes and recording of the findings.

[0012] Preferably, after step S3, the process further includes a post-plugging inspection of the borehole: after plugging is completed, the stability of the plugging assembly and the condition of the detonating cord are confirmed; the construction site is inspected and cleaned, and original records of the loading and plugging are made.

[0013] Preferably, the recorded content includes basic information about the explosive loading, blockage status, problems encountered, and their handling measures.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The plugging component, through its clamping action, fits tightly against the inner wall of the borehole and fills the gaps, effectively preventing powdered ammonium nitrate explosive from falling out of the borehole or returning to its original state. This ensures the explosive remains stably within the borehole, avoiding waste and potential safety hazards caused by falling explosive. Construction is convenient and efficient, reducing labor intensity. The plugging component material is readily available and inexpensive; the appropriate plugging component size can be selected based on the diameter of the upward-facing borehole to accommodate different specifications. The construction steps are clear and simple, requiring no complex construction techniques, effectively reducing the workload of repeated loading, lowering the labor intensity of operators, and improving blasting efficiency. It also improves the rock fragmentation effect, reduces the difficulty of subsequent cleanup operations, and lowers safety risks such as flyrock, hole punching, and blasting noise during blasting, ensuring the safety and stability of blasting operations. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic flowchart of a method for sealing upward blast holes in an underground mine, according to the present invention. Figure 2 This is a schematic diagram showing the usage status of the plugging component in an upward blast hole plugging construction method for underground mines according to the present invention; Figure 3 This is a schematic diagram of the plugging component structure in an upward blast hole plugging construction method for underground mines according to the present invention; Figure 4 This is a schematic diagram of the structure of the plugging component before compression in the above-ground blast hole plugging construction method of the present invention; Figure 5 This is a schematic diagram of the structure of the plugging component after compression in the above-ground blast hole plugging construction method of the present invention.

[0017] In the attached diagram, 1-blast hole, 2-detonating cord, 3-upper movable block, 4-lower movable block, 5-reserved gap, 6-wedge-shaped surface, 7-nail, 8-flexible filling material. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] Please see Figure 1 and Figure 2 This invention provides a method for plugging an upward blast hole 1 in an underground mine, comprising the following steps: S1. Loading and feeding pipe for borehole 1: Pour the bagged explosives, which have been mixed on-site, into the tank of the manual compressed air loader one by one. After pouring, close the sealing cap of the compressed air loader to ensure a good seal and prevent air or explosive leakage during the loading process. The operator will then feed the delivery pipe and detonating cord 2 together into the bottom of borehole 1, ensuring that the end of the detonating cord 2 reaches the preset position at the bottom of the hole and that the end of the delivery pipe is tightly against the bottom of borehole 1. S2. Compressed Air Delivery and Pipe Retraction: After confirming that the delivery pipe and detonating cord 2 are in place, the mixed explosive is delivered into borehole 1 using a manual compressed air loader. After filling, the delivery pipe is withdrawn and delivery is stopped. During delivery, the personnel delivering the delivery pipe and the personnel operating the delivery switch cooperate with each other to observe the air and explosive discharge of borehole 1 in real time to ensure that the air and explosive discharge are normal, without blockage or leakage. When it is observed that the air and explosive discharge are both normal, the personnel delivering the delivery pipe slowly withdraw the delivery pipe at a uniform speed until the end of the delivery pipe is withdrawn to the position corresponding to the designed charge amount of borehole 1. After filling, the delivery switch is turned off, and then the air supply switch is turned off to stop delivery and avoid excessive explosive charge.

[0023] S3. Hole 1 plugging: After the charge is completed, immediately insert the plugging component into hole 1 until it reaches the charge surface; use a long ram to insert into hole 1 and compact the plugging component so that the upper and lower movable ends of the plugging component are misaligned and squeezed together in hole 1, tightly fitting against the inner wall of hole 1; flexible filling material 8 fills the gap between the plugging component and the inner wall of hole 1 to achieve double sealing, ensuring that the powdered explosive does not leak, return powder, or fall off; during the plugging process, avoid tamping the filling material that is in direct contact with the explosive, and avoid flattening, squeezing, or pulling the detonating cord 2.

[0024] like Figures 3 to 5 As shown, the blocking assembly includes an upper movable block 3 and a lower movable block 4. The opposing surfaces of the upper movable block 3 and the lower movable block 4 are complementary wedge-shaped surfaces 6. They are connected by fastening pins with a gap 5. When the upper movable block 3 is pressed, the fastening pins deform, and the two opposing wedge-shaped surfaces 6 squeeze each other. The upper movable block 3 and the lower movable block 4 move closer to the inner wall of the borehole 1. A flexible filling material 8 is provided between the upper movable block 3 and the lower movable block 4 and the inner wall of the borehole 1.

[0025] Furthermore, it also includes the following steps: Blocking component processing: Take a pair of the upper movable block 3 and the lower movable block 4, make their wedge-shaped surfaces 6 face each other, and use the fastening pin to drive it into the upper movable block 3 or the lower movable block 4. The driving direction of the fastening pin is perpendicular to the wedge-shaped surface 6. Cover the periphery of the assembled blocking component with flexible filling material 8.

[0026] Furthermore, the reserved gap 5 is in the range of 5~10mm.

[0027] Furthermore, the diameters of the upper movable block 3 and the lower movable block 4 range from 50 to 55 mm, and the overall length after combination is 200 to 220 mm.

[0028] Furthermore, the flexible filling material 8 includes straw and thatch.

[0029] Furthermore, before step S1, there is also a step of making explosive bags: according to a preset ratio, powdered ammonium nitrate explosive and diesel oil are poured into a mixing container and stirred to ensure that the explosive and diesel oil are mixed evenly, and that the mixed explosive is free of lumps and stratification; after stirring, the evenly mixed explosive is packed into a packaging bag.

[0030] Furthermore, before step S1, the process includes an inspection of the construction site and equipment: a comprehensive cleanup of the blasting operation site is conducted, removing obstacles, demarcating a charging warning zone, and checking the air pressure of the manual compressed air charging device to ensure there is no damage or leakage. Simultaneously, the connection of the on-site air supply pipe is checked, and the air pressure is tested to ensure it meets construction requirements, ensuring stable air pressure to meet the normal operating needs of the manual compressed air charging device and preventing charging difficulties due to insufficient air pressure or equipment malfunction. The blast hole 1 is inspected and accepted to ensure it is free from blockages and collapses, and that its depth and diameter meet design requirements. Inspection records are made and preserved.

[0031] Furthermore, after step S3, the process includes a post-plugging inspection of borehole 1: After plugging is completed, the stability of the plugging assembly and the condition of the detonating cord 2 are confirmed; the construction site is inspected and cleaned, and original records of the charging and plugging are prepared. The records include basic information about the charging, the plugging situation, any problems encountered, and their handling measures.

[0032] Example In an underground mine, deep-hole blasting operation is carried out. Hole 1 has a diameter of 65mm and a depth of 9m. Powdered ammonium nitrate explosive is used for charging. The plugging structure and construction method of this invention are employed. The specific implementation steps are as follows: Processing of round wooden wedges (plugging components): Select a round wooden post with a diameter of 50mm and a length of 200mm that is free from cracks and decay. Cut it diagonally with a saw to obtain two wedge-shaped wooden blocks (i.e., upper movable block 3 and lower movable block 4). Take a thin nail 7 with a diameter of 2mm and a length of 20mm and drive it through the connection between the two wedge-shaped wooden blocks from the direction perpendicular to the wedge surface 6, so that a 5-10mm offset space is formed between the wedge surfaces 6 of the upper movable block 3 and the lower movable block 4, thus making a round wooden wedge.

[0033] Site and equipment inspection: Clear the blasting operation site, remove loose rocks and debris, and demarcate the warning zone; inspect the manual compressed air charging equipment to ensure that the tank and delivery pipe are undamaged, properly grounded, and the grounding resistance is not greater than 1×10⁻⁶. 5 Ω; Check that the air supply duct connection is secure and test the air pressure to be 5×10. 5 Pa meets construction requirements; inspect borehole 1 to ensure that the hole depth and diameter meet design requirements, and that there is no blockage or collapse.

[0034] Explosive mixing and bagging: Pour the powdered ammonium nitrate explosive and diesel oil into a mixing container according to a mass ratio of 100:4, mix thoroughly, and pack into special packaging bags, with each bag weighing 30kg.

[0035] Loading explosives into borehole 1: Pour the bagged explosives into the manual compressed air loading device and seal the cap; send the delivery pipe and detonating cord 2 together into the bottom of borehole 1, ensuring that the end of the detonating cord 2 reaches the bottom of the hole and the delivery pipe is close to the bottom of the hole.

[0036] Compressed air delivery and withdrawal of the delivery pipe: Slowly open the air supply switch, and after the air pressure stabilizes, open the delivery switch. After observing that the air and explosives are coming out of borehole 1 normally, slowly withdraw the delivery pipe until the end of the delivery pipe is 1.8m away from the borehole opening (the position corresponding to the designed charge). Then close the delivery switch and the air supply switch. At this time, the charge in borehole 1 meets the design requirements.

[0037] Blocking of borehole 1: Wrap dry straw around a wooden wedge and insert it into borehole 1 until it reaches the surface of the explosive. Use a long rod to slowly press the wooden wedge firmly into borehole 1, and fill the gaps with straw to ensure that the explosive does not turn into powder or fall off.

[0038] Subsequent inspection: Check the blockage of borehole 1, confirm that the wooden wedges are firmly installed and there is no powdering or dropping of the blasting agent; clean the site and make construction records.

[0039] In summary, the plugging component, through its clamping action, fits tightly against the inner wall of borehole 1 and fills the gaps, effectively preventing powdered ammonium nitrate explosive from falling out of the borehole or returning to its original state. This ensures the explosive remains stably within the borehole, avoiding waste and potential safety hazards caused by falling explosive. Construction is convenient and efficient, reducing labor intensity. The plugging component material is readily available and inexpensive; appropriate plugging component sizes can be selected based on the diameter of the upward-facing borehole 1 to accommodate different specifications. The construction steps are clear and simple, requiring no complex construction techniques, effectively reducing the workload of repeated loading, lowering the labor intensity of operators, and improving blasting efficiency. It also improves the rock fragmentation effect, reduces the difficulty of subsequent cleanup operations, and lowers safety risks such as flyrock, hole punching, and blasting noise during blasting, ensuring the safety and stability of the blasting operation.

[0040] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for plugging upward blast holes in underground mines, characterized in that, Includes the following steps: S1. Loading and feeding pipe for blast hole: The operator feeds the blast hole pipe and detonating cord together into the bottom of the blast hole, ensuring that the end of the detonating cord reaches the preset position at the bottom of the hole and the end of the blast hole pipe is close to the bottom of the blast hole. S2. Compressed air delivery and tube withdrawal: After confirming that the delivery tube and detonating cord are in place, the mixed explosive is delivered into the borehole through a manual compressed air loading device. After filling, the delivery tube is withdrawn and delivery is stopped. S3. Hole plugging: After the charge is completed, immediately insert the plugging component into the hole until it reaches the charge surface; use a long gun barrel to insert into the hole and press the plugging component so that the upper and lower movable ends of the plugging component are misaligned and squeezed against each other in the hole, tightly fitting against the inner wall of the hole. The blocking assembly includes an upper movable block and a lower movable block. The opposing surfaces of the upper and lower movable blocks are complementary wedge-shaped surfaces. They are connected by fastening pins with a gap. When the upper movable block is pressed, the fastening pins deform, and the two opposing wedge-shaped surfaces squeeze each other. The upper and lower movable blocks move closer to the inner wall of the borehole. A flexible filling material is provided between the upper and lower movable blocks and the inner wall of the borehole.

2. The method for plugging upward blast holes in an underground mine according to claim 1, characterized in that, It also includes the following steps: Blocking component processing: Take a pair of the upper movable blocks and the lower movable blocks, make their wedge-shaped surfaces face each other, and use the fastening pins to drive them into the upper movable blocks or the lower movable blocks, with the driving direction of the fastening pins perpendicular to the wedge-shaped surfaces; cover the periphery of the assembled blocking component with flexible filler material.

3. The method for plugging upward blast holes in an underground mine according to claim 1, characterized in that, The reserved gap ranges from 5 to 10 mm.

4. The method for plugging upward blast holes in an underground mine according to claim 1, characterized in that, The diameters of the upper movable block and the lower movable block range from 50 to 55 mm, and the overall length after combination is 200 to 220 mm.

5. A method for plugging upward blast holes in an underground mine according to claim 1 or 2, characterized in that, The flexible filling material includes rice straw and thatch.

6. The method for plugging upward blast holes in an underground mine according to claim 1, characterized in that, Before step S1, there is also a step of making explosive bags: pouring powdered ammonium nitrate explosive and diesel into a mixing container and stirring according to a preset ratio; after stirring, packing the evenly mixed explosive into a packaging bag.

7. A method for plugging upward blast holes in an underground mine according to claim 1, characterized in that, Before step S1, the following steps are also included: a comprehensive cleanup of the blasting operation site, removal of obstacles, delineation of the charging warning zone, inspection of the air pressure of the manual air pressure charging device, and inspection and acceptance of the blast holes and recording of the findings.

8. A method for plugging upward blast holes in an underground mine according to claim 1, characterized in that, Step S3 is followed by a post-hole plugging inspection: after plugging is completed, the stability of the plugging assembly and the condition of the detonating cord are confirmed; the construction site is inspected and cleaned, and original records of the loading and plugging are made.

9. A method for plugging upward blast holes in an underground mine according to claim 8, characterized in that, The records include basic information about the explosive loading, blockages, problems encountered, and their handling measures.

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