Tubular interval charging structure and blasting method applied by tubular interval charging structure

Abstract

The invention discloses a tubular interval charging structure and a blasting method applying the same. The tubular interval charging structure comprises an energy gathering pipe and explosive sections, wherein the energy gathering pipe is inserted in a manner of clinging to the inner wall of a blast hole, and the explosive sections are filled in the energy gathering pipe at intervals in a segmented manner; the inner side pipe wall, corresponding to the explosive section, of the energy gathering pipe is provided with an energy gathering cone facing the center of the pipe, and the explosive side face of the explosive section is shaped through the energy gathering cone to form an outward energy gathering cavity; a metal powder layer is arranged on the side wall, making contact with the explosive section, of the energy gathering cone. According to the tubular interval charging structure, the energy gathering caves are formed in the side faces of the explosive sections which are filled in the energy gathering pipes at intervals in a segmented mode, the blasting penetrating capacity is enhanced, uniform distribution and fine regulation and control of blasting energy in blast holes are achieved, the utilization rate of the blasting energy is increased, the efficiency of mining engineering is improved through the blasting method applied by the tubular interval charging structure, and the blasting efficiency is improved. The economic cost is reduced, the rock mass crushing efficiency is improved, meanwhile, the blasting safety is guaranteed, and the requirements of modern mining are met.

Description

Technical Field

[0001] The present invention relates to a tubular interval charge structure and a blasting method using the same, and belongs to the technical field of mining blasting. Background Art

[0002] During the process of mine exploitation, the rock blasting process is actually a process of explosive energy distribution and transfer. Using existing technologies to regulate explosive energy and make the energy reasonably distributed is of great significance for improving the mine exploitation efficiency. In the blasting with traditional charge structures, at least 50% of the blasting energy acts on the excessive crushing inside the rock, while the block size of the upper ore block is too large. To achieve the expected blasting effect, secondary blasting or even multiple blasts are required, which reduces the engineering efficiency.

[0003] To improve the distribution of explosion energy, interval charge technology is commonly used in engineering practice. For example, a water sandbag interval charge smooth blasting structure and blasting method disclosed in a Chinese patent application with the application number CN202311237533.7. However, the interval charge structure still has many deficiencies in practice: on the one hand, using interval charge makes the blasting energy act on air or interval media, and the blasting gas diffuses through microcracks and pores on the rock surface, increasing the degree of rock fragmentation, but local concentration occurs, the fragmentation effect is uneven, and it is easy to cause instability of the surrounding rock structure after blasting; on the other hand, the existence of the interval structure makes the propagation path of shock waves in the rock longer, the throw distance after blasting is longer, and the blasting safety needs to be improved. In addition, due to the large amount of nitrogen oxides and carbon monoxide particles contained in the smoke and dust generated by the chemical reaction after explosive blasting, it is easy to pollute the blasting operation environment. Summary of the Invention

[0004] The technical problem solved by the present invention is: aiming at the problems of uneven rock fragmentation and unstable surrounding rock structure caused by uneven distribution of blasting energy in the existing interval charge blasting technology, a tubular interval charge structure and a blasting method using the same are provided.

[0005] The present invention is realized by adopting the following technical solutions:

[0006] The present invention first discloses a tubular interval charge structure, which includes a shaped charge tube 100 inserted closely against the inner wall of the blast hole and explosive segments 200 filled in the shaped charge tube at intervals in segments;

[0007] On the inner side wall of the shaped charge tube 100 corresponding to the explosive segments, shaped charge cones 101 are provided facing the center of the tube, and the sides of the explosives of the explosive segments 200 are shaped by the shaped charge cones to form shaped charge cavities 201 facing outwards;

[0008] The side wall of the shaped charge cone 101 in contact with the explosive segment is provided with a metal powder layer 102.

[0009] In the pipe-type interval charge structure of the present invention, further, several groups of shaped charges 101 are axially distributed along the inner wall of the shaped charge pipes on both sides of the explosive section. The circumferential azimuth of the shaped charges distributed axially in the shaped charge pipes is aligned with the azimuth of the line connecting the current blast hole and the adjacent blast hole, and the groups of shaped charges 101 on the same axis are evenly distributed at equal intervals.

[0010] In the pipe-type interval charge structure of the present invention, further, the total area of the bottom of the shaped charge 101 accounts for 15-25% of the inner wall surface area of the shaped charge pipe 100.

[0011] In the pipe-type interval charge structure of the present invention, further, the metal powder layer 102 is a copper powder layer sprayed on the surface of the shaped charge.

[0012] In the pipe-type interval charge structure of the present invention, further, the shaped charge pipe 100 is a PVC pipe with a pore diameter of 80-90% of the outer diameter, and the PVC pipe is provided with a grounding conductive silica gel connecting the inner wall and the surrounding rock of the blast hole.

[0013] In the pipe-type interval charge structure of the present invention, further, the outer wall of the shaped charge pipe 100 is sprayed with an Al2O3-ZrO2 composite ceramic coating.

[0014] In the pipe-type interval charge structure of the present invention, further, an air spacer 400 is arranged between the explosive sections 200, so that the explosive sections are arranged in segments in the shaped charge pipe. A stemming section 300 is arranged at the top of the shaped charge pipe close to the blast hole outlet to seal the charge structure in the shaped charge pipe, and all the explosive sections 200 are connected to the detonation network through electronic detonators 500.

[0015] In the pipe-type interval charge structure of the present invention, further, the explosive section is filled with bulk explosives into the pipe section of the shaped charge pipe 100 corresponding to the shaped charge. Among them, emulsion explosives are used for hard rock around the blast hole, and ammonium fuel oil explosives are used for mudstone around the blast hole.

[0016] The present invention also discloses a blasting method using the above pipe-type interval charge structure, including the following steps:

[0017] Step 1: Explore and divide the blasting area, investigate the geological conditions of the area, and determine the hole layout parameters according to the ore body lithology, structural characteristics and blasting objectives;

[0018] Step 2: Use a drill to drill holes according to the hole layout parameters and maintain the blast holes;

[0019] Step 3: Prefabricate the shaped charge pipes used in the above-mentioned pipe-type interval charge structure of the present invention according to the hole layout plan. On the inner side wall of the shaped charge pipe, a shaped charge cone facing the center of the pipe is processed. The circumferential orientation of the shaped charge cone distributed axially in the shaped charge pipe is aligned with the orientation of the line connecting the corresponding blast hole and the adjacent blast hole. Spray copper powder onto the surface of the shaped charge cone inside the shaped charge pipe to form a metal powder layer. Spray an Al2O3-ZrO2 composite ceramic coating on the outer wall of the shaped charge pipe. Insert the prefabricated shaped charge pipe into the blast hole. When installing the shaped charge pipe, according to the hole layout plan between the blast holes, select the corresponding shaped charge pipe and align the orientation of the shaped charge cone provided thereon with the orientation of the line connecting the adjacent blast holes;

[0020] Step 4: Fill the shaped charge pipe with explosive segments and electronic detonators in a segmented and spaced manner according to the pipe-type interval charge structure of Claims 1-8. The segmented explosive segments correspond to the areas where the shaped charge cones are located inside the shaped charge pipe;

[0021] Step 5: Connect the electronic detonators in all the blast holes through wires to form a delay initiation network, and tightly seal the blast holes with stemming;

[0022] Step 6: Initiate the detonation. After the blasting is completed, collect the image of the muck pile, and use the WipFrag digital image analysis system to statistically analyze the fragment size distribution.

[0023] In the above-mentioned blasting method using the pipe-type interval charge structure of the present invention, further, the delay of the delay initiation network includes the delay between holes and the delay between rows. The calculation formula for the delay time Δt is as follows:

[0024] ,

[0025] In the formula: w is the single-hole charge amount of the explosive, V p is the blasting wave velocity, K1 is the empirical correction coefficient, W is the energy required for blasting, C p is the specific heat capacity of the rock, S is the hole spacing, and V is the volume of the blasting area.

[0026] The above technical solution adopted by the present invention has the following beneficial effects:

[0027] (1) In the pipe-type interval charge structure of the present invention, by arranging shaped charge cones on both sides of the inner side wall of the shaped charge pipe, after filling the shaped charge pipe with explosives, a conical cavity-shaped shaped charge cavity is integrally formed on the side of the explosive segment. When the energy generated by the explosion of the explosive is dispersed, it first concentrates towards the axis of the conical shaped charge cavity to form a shaped charge air flow. After the shaped charge air flow reaches the maximum concentration point, it then disperses, making the blasting energy disperse in multiple directions, weakening the main stress concentration effect in the blast hole. Combining with the copper metal powder layer lined on the shaped charge cone greatly improves the concentration degree of the shaped charge air flow, thereby generating a great penetration ability for the surrounding rock of the blast hole, making the blasting energy of the explosive more evenly distributed inside the rock, resulting in uniform fragmentation of the blasted ore blocks and shorter throw distances.

[0028] (2) The tubular interval charge structure of the present invention adopts an interval charge structure in the explosive section within the shaped charge tube. The explosive sections are separated by air. The blasting waves generated by the explosion of the explosive sections are transmitted to the gas and then to the rock mass from the blast hole. The shaped charge airflows generated by the shaped charge cavities converge towards the axis of the conical cavities and then disperse, ensuring the uniformity of energy distribution. It not only effectively reduces the formation of large blocks after blasting, but also does not cause local over-crushing, facilitating the loading and transportation after blasting, effectively improving the engineering efficiency and reducing costs.

[0029] (3) The blasting method of the tubular interval charge structure of the present invention effectively improves the utilization rate of explosives by setting the in-hole electronic detonator delay, the between-hole delay, and the between-row delay, and adopting an air interval charge structure. The shaped charge structure of the tubular interval charge structure combined with the delay initiation of the initiation network can avoid the problem that the explosion waves are too concentrated and the ore body in the blasting area cannot be effectively crushed, enabling the stable propagation of the explosion energy. The air interval structure in the blast hole can raise the height of the charge column, promote the dispersion of the blasting energy in the hole, strengthen the reflection and superposition of the explosive shock waves, and extend the action time of the stress waves. This method strengthens the effective control of the blasting energy, avoids energy waste, and effectively improves the utilization rate of the blasting energy.

[0030] (4) When loading the charge in the tubular interval charge structure of the present invention, the type of explosive loaded is determined by identifying the lithology, effectively improving the blasting efficiency. If the overall lithology is hard rock, the explosive sections in the hole are all loaded with emulsion explosive; if the overall lithology is hard rock, the explosive sections in the hole are all loaded with ammonium nitrate fuel oil explosive; if the lithology is a mixture of mudstone and hard rock, the explosive sections corresponding to the mudstone sections are loaded with ammonium nitrate fuel oil explosive, and the explosive sections corresponding to the hard rock sections are loaded with emulsion explosive. This method combines with the lithology of the blasting area, adapts to the geological environment, effectively reduces the unit consumption of explosives, and reduces the engineering cost.

[0031] In summary, the tubular interval charge structure provided by the present invention forms shaped charge cavities on the sides of the explosive sections filled in segments and at intervals within the shaped charge tube, enhancing the blasting penetration ability, realizing the uniform distribution and fine control of the blasting energy in the blast hole, improving the utilization rate of the blasting energy. The applied blasting method improves the efficiency of the mine exploitation project, reduces the economic cost, ensures the safety of blasting while improving the rock fragmentation efficiency, and meets the requirements of modern mine exploitation.

[0032] The following further illustrates the present invention in conjunction with the drawings and specific embodiments. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the shaped charge tube being inserted into the blast hole in the embodiment.

[0034] Figure 2 It is a schematic diagram of the explosive section being shaped by the shaped charge tube to form a shaped charge cavity in the embodiment.

[0035] Figure 3Schematic diagram of the blasting air flow of the shaped charge cavity in the embodiment.

[0036] Figure 4 Schematic diagram of the spaced charge structure inside the shaped charge tube in the embodiment.

[0037] Figure 5 Schematic diagram of the process flow of the blasting method using the tubular spaced charge structure in the embodiment.

[0038] Figure 6a 、 6b Figures 6a, 6b, and 6c are schematic diagrams of the circumferential azimuth of the axial distribution of the shaped charge cones on the shaped charge tubes under three common hole - layout methods.

[0039] Reference numerals in the figure: 100 - shaped charge tube, 101 - shaped charge cone, 102 - metal powder layer, 103 - composite ceramic layer, 200 - explosive section, 201 - shaped charge cavity, 300 - stemming section, 400 - air spacer, 500 - electronic detonator, 501 - detonator connecting wire, 600 - blast hole. Detailed implementation mode

[0040] Embodiment

[0041] The tubular spaced charge structure of this embodiment is a specific implementation scheme of the present invention. As Figure 1 shown, this tubular spaced charge structure uses the shaped charge tube 100 as the container for loading explosives. The shaped charge tube 100 is inserted closely against the inner wall of the blast hole into the blast hole 600, and the explosive sections 200 are loaded in the shaped charge tube 100 at intervals by segments. While the shaped charge tube 100 serves as the container for loading explosives, it also plays a role in supporting and protecting the inner wall of the blast hole. A number of shaped charge cones 101 are arranged on the inner wall of the shaped charge tube 100. The distribution area of the shaped charge cones 101 is the inner wall of the shaped charge tube corresponding to the explosive section. The tip of the shaped charge cone 101 is arranged towards the center of the shaped charge tube, and the bottom end is located on the inner wall of the shaped charge tube. After the explosive is filled into the area of the shaped charge cone 101 in the shaped charge tube 100, the shaped charge cone 101 forms an outward - facing shaped charge cavity 201 on the side of the explosive in the explosive section, as Figure 2 and Figure 3 shown.

[0042] In this embodiment, the shaped charge cavity 201 is formed on the side of the explosive section 200 and is a conical cavity corresponding to the shape of the shaped charge cone 101. When the explosive energy diffuses, it first concentrates towards the axis of the shaped charge cavity to form a shaped charge air flow. After the shaped charge air flow reaches the maximum concentration point at the tip of the shaped charge cone, it then disperses, as specifically shown by the arrows in Figure 3 . A metal powder layer 102 is provided on the outer wall of the shaped charge cone 101 in contact with the explosive section. The metal powder layer 102 in this embodiment is a layer of copper powder sprayed on the surface of the shaped charge cone. Applying a copper metal coating on the side wall of the shaped charge cone 101 can greatly improve the concentration degree of the shaped charge air flow towards the tip of the shaped charge cavity, thereby generating a great penetration ability for the explosive energy to diffuse from the shaped charge cavity.

[0043] According to the regular hole layout orientation of the blast holes, several groups of the shaped charge cones 101 are axially distributed along the inner walls of the shaped charge tubes on both sides of the explosive section. From the cross-section of the shaped charge tube, the circumferential orientation of the shaped charge cones axially distributed in the shaped charge tube is aligned with the orientation of the connection line between the blast hole where they are located and the adjacent blast hole. The groups of the shaped charge cones 101 on the same axis are evenly distributed at equal intervals, and combined with the hole layout scheme of the blast holes, the rock mass in the blasting area is uniformly broken.

[0044] The total area of the bottoms of all the shaped charge cones 101 on the shaped charge tube 100 accounts for 15 - 25% of the inner wall surface area of the shaped charge tube 100. The calculation formula is as follows:

[0045] Ratio of the total area of the bottoms of the shaped charge cones = . Reasonably controlling the number of the shaped charge cones can not only ensure the shaped charge blasting effect but also ensure the structural strength of the shaped charge tube.

[0046] The shaped charge tube 100 is made of a PVC tube, and the tube aperture is 80 - 90% of the outer diameter. The PVC tube is provided with a grounding conductive silica gel connecting the inner wall and the surrounding rock of the blast hole, which can effectively prevent static electricity generated when filling explosives into the shaped charge tube.

[0047] In addition, in this embodiment, an Al2O3-ZrO2 composite ceramic coating 103 is sprayed on the outer wall of the shaped charge tube 100. The Al2O3-ZrO2 composite ceramic coating 103 is formed by uniformly dispersing Al2O3 particles and ZrO2 particles in a molar ratio of 3:1 to form a composite phase, and the two phases are connected by an oxygen bridge bond (Al-O-Zr). Then, using the plasma spraying technology, the dispersed suspension is sprayed onto the outer surface of the shaped charge tube to form a dense coating. The spraying thickness of the ceramic layer is about 10 - 20 microns, covering the outer wall surface of the PVC tube of the shaped charge tube, presenting a nanostructure. After the shaped charge tube is broken by blasting, the nanostructure of the composite ceramic coating on it captures small molecule gases such as NOx and CO generated after the explosion of the explosive through van der Waals forces. The NOx emission is reduced by at least 50% in a single blasting, and the CO concentration is reduced to <10 ppm, reducing environmental pollution. At the same time, the Al2O3-ZrO2 composite ceramic coating can maintain stable performance in the environment of -40°C to 2000°C, has extremely high thermal stability and chemical inertness, further ensures the safety and environmental protection of the blasting process, and is applicable to the deep well high-temperature blasting scenario.

[0048] The explosive segments are filled with bulk explosives into the tube sections of the focused tube 100 corresponding to the focusing cones. Emulsion explosives are used for hard rock surrounding the blasthole, while ammonium nitrate explosives are used for mudstone surrounding the blasthole. During the bulk explosive filling process, the space formed by the focusing cones shapes a focusing cavity for the filled explosive segments. The focusing cones are only placed in the tube sections corresponding to the explosive segments, and are filled sequentially from bottom to top within the focused tube sections using bulk explosives. The inner walls of the remaining tube sections separated by explosives are kept smooth to facilitate installation of air spacers in the corresponding separated sections. This prevents the focusing cones from squeezing the inflated air spacers, potentially damaging them, and also prevents gaps between the focusing cones and the air spacers, which could cause seal failure between the explosive segments.

[0049] See also Figure 4 In this embodiment, the tubular spaced charge structure as a whole also includes air spacers 400 that divide the multiple explosive segments 200 into sections and a packing segment 300 that seals the charge structure within the focusing tube. Air spacers 400 are provided between the explosive segments 200 to achieve the segmented and spaced arrangement of the explosive segments 200 within the focusing tube. The packing segment 300 is provided at the top of the focusing tube near the blasthole outlet to seal the charge structure within the focusing tube. All explosive segments 200 are connected to electronic detonators 500, and the electronic detonators 500 are connected to the blasting network via detonator connecting lines 501. When setting up the tubular spaced charge structure, first install the air spacer 400 at the bottom of the focusing tube 100. Then, the explosive segments 200 and other air spacers 400 are sequentially added. The explosive segments 200 are filled with bulk explosives and compacted. The electronic detonator 500 for detonation is also placed at the same time as the explosive segments. The air spacers 400 are placed into the focusing tube in a compressed state and then inflated to isolate the internal space between the explosive segments. This prevents the focusing cone from blocking the air spacers. After all the spaced explosive segments are installed, taphole mud is added to the focusing tube above the outermost explosive segment and compacted to form the packing section 300.

[0050] like Figure 5 As shown, the construction process of the blasting method using the tubular spaced charge structure of this embodiment is as follows:

[0051] Step 1: Exploration and division of blasting area, investigation of regional geological conditions, determination of hole layout parameters according to ore body lithology, structural characteristics and blasting targets, selection of explosive type and amount according to ore body lithology.

[0052] This embodiment takes a triangular hole arrangement as an example, and the hole spacing L used in the triangular hole arrangement is calculated as follows:

[0053] ,

[0054] Where S is the reference spacing of hole layout, ranging from 1 to 2m.

[0055] The calculation formula for explosive unit consumption Q is as follows:

[0056] ,

[0057] Where: W is the total amount of explosive, and V is the volume of rock in the blasting area.

[0058] Step 2: Use a drill to drill holes according to the hole layout parameters and maintain the blast holes.

[0059] Use a down-the-hole drill to layout holes according to the hole layout parameters and maintain them. The depth of the blast hole is 10 m, and the thickness of the residual rock slag at the bottom of the hole is less than 10 cm. After drilling, use a high-pressure air gun to clean the debris in the hole to ensure the integrity of the blast hole wall.

[0060] Step 3: Prefabricate the shaped charge tube used in the above-mentioned tubular interval charge structure of the present invention according to the hole layout plan. A shaped charge cone facing the center of the tube is processed on the inner wall of the shaped charge tube. The circumferential orientation of the shaped charge cone distributed axially in the shaped charge tube is aligned with the orientation of the connection line between the corresponding blast hole and the adjacent blast hole. Spray copper powder on the surface of the shaped charge cone in the shaped charge tube to form a metal powder layer. Spray an Al2O3-ZrO2 composite ceramic coating on the outer wall of the shaped charge tube. Insert the prefabricated shaped charge tube into the blast hole. When installing the shaped charge tube, according to the hole layout plan between the blast holes, select the corresponding shaped charge tube and adjust the orientation of the shaped charge cone set on it to be aligned with the orientation of the connection line between the adjacent blast holes and then insert it into the blast hole.

[0061] The shaped charge tube is made of PVC tube. The outer diameter is selected according to the diameter of the blast hole. The hole diameter is 80-90% of the outer diameter. The wall thickness is generally 2-4 mm. The tube length is selected according to the depth of the blast hole as 10 m. 5-7 shaped charge cones are symmetrically arranged on both sides of the inner wall of the shaped charge tube corresponding to each explosive section. The total area of the bottoms of all the shaped charge cones accounts for 15-25% of the inner wall surface area of the 100-shaped charge tube.

[0062] When inserting the shaped charge tube into the blast hole, according to the hole layout plan of the blast hole, align the orientation of the shaped charge cone set on it with the orientation of the connection line between the adjacent blast holes.

[0063] See Figure 6a , 6b and 6c, which show three common blast hole layout methods. In the triangular hole layout method, after the shaped charge tube 100 is inserted into the blast hole, the shaped charge cavity 201 formed by the shaped charge cone in the explosive section should be set facing the direction of the connection line between the adjacent blast holes, as shown in Figure 6a . That is, the connection line of each row of shaped charge cones in the axial direction of the shaped charge tube should point to the direction of the adjacent blast hole. In this way, when the explosion occurs, the directional blasting energy generated by the shaped charge cavity will directly act on the rock mass between the adjacent blast holes, forming an optimized stress field distribution and improving the fragmentation efficiency.

[0064] In the rectangular hole layout method, after the shaped charge pipe 100 is inserted into the blast hole, the shaped charge cavities 201 formed by the shaped charge cones on it in the explosive section should be evenly distributed according to the four main directions of the rectangular grid, that is, the axes of the shaped charge cones are distributed at four azimuths on the pipe circumference with an interval of 90°, and the shaped charge cavities 201 formed in the explosive section respectively point to the positions of the adjacent four blast holes, as Figure 6b shown. This layout ensures that the blasting energy is evenly distributed on the horizontal plane and avoids the formation of areas that are not fully fragmented.

[0065] In the circular hole layout method, after the shaped charge pipe 100 is inserted into the blast hole, the axial distribution azimuth of the shaped charge cones on it is radially distributed in the circumferential direction of the shaped charge pipe according to the number of blast holes distributed on the outer circumference, covering a range of 360°. The included angle interval between the shaped charge cones corresponds to the included angle of the blast holes distributed on the outer circumference, as Figure 6c shown. This layout is applicable to large-scale blast hole blasting or blasting operations under special geological conditions.

[0066] In actual operation, it should be ensured that the azimuth of the shaped charge cone is accurately corresponding to the azimuth of the connection line between the installed blast hole and the adjacent blast hole under the predetermined hole layout plan when loading into the blast hole. In addition, for complex geological conditions, the orientation of the shaped charge cone can be appropriately adjusted based on the weak surface or joint surface direction of the rock mass structure to further optimize the blasting effect.

[0067] Step Four: Segmentally and intermittently fill the shaped charge pipe with explosive segments and electronic detonators according to the tubular intermittent charge structure described above in this embodiment. The segmented explosive segments correspond to the areas where the shaped charge cones are located in the shaped charge pipe.

[0068] In the shaped charge pipe, an intermittent charge method is adopted. From bottom to top in the pipe are an air spacer, an explosive segment, an air spacer, an explosive segment, and a stemming segment. The air spacer used in this embodiment is 0.5 m long. The first explosive segment in the lower layer is 3.5 m long, the second explosive segment in the upper layer is 2.5 m long, and the remaining stemming segment is 3 m long.

[0069] The air spacer is inflated after being installed in place through the space in the shaped charge pipe in a compressed state. The air spacer causes the energy during the explosion of the explosive segment to mix with air to form a blasting air current, and after obtaining energy, the blasting air current acts on the rock through the shaped charge cones on the shaped charge pipe.

[0070] The type of explosive for the explosive section is determined according to the specific geological conditions of the blasting area. After loading, the perforating tube at the outlet of the blast hole is plugged with stemming. If the lithology around the blast hole is all hard rock, emulsion explosive is loaded in all explosive sections; if the lithology around the blast hole is all hard rock, ammonium nitrate fuel oil explosive is loaded in all explosive sections. If the lithology is stratified, ammonium nitrate fuel oil explosive or emulsion explosive is selected and loaded in segments according to the lithology corresponding to the rock layer area where the explosive section is located. The explosive section is filled with bulk explosive evenly in the PVC pipe, and the explosive density is controlled at 0.8 - 1.0 g / cm³. Before loading the explosive, a millisecond delay detonator is installed at the corresponding position of the explosive section. After filling the explosive, the electronic detonator is buried at the bottom of the explosive section, and the detonator connecting wire is connected to the connecting wire in the blasting area to form a detonation network.

[0071] Step Five: Connect the electronic detonators in all blast holes through wires to form a delay detonation network, and tightly seal the blast holes with stemming.

[0072] The delay of the delay detonation network corresponding to this embodiment includes the delay between holes and the delay between rows. The calculation formula for the delay time Δt is as follows:

[0073] ,

[0074] w is the single-hole charge of the explosive, V p is the blasting wave velocity, K1 is the empirical correction coefficient, W is the energy required for blasting, C p is the specific heat capacity of the rock, S is the hole spacing, and V is the volume of the blasting area. Through calculation, the delay between holes of the delay detonation network in this embodiment is 15 ms, and the delay between rows is 40 ms.

[0075] Step Six: Initiate the detonation. After the blasting is completed, collect the image of the muck pile, and use the WipFrag digital image analysis system to statistically analyze the block size distribution.

[0076] In this text, the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the clarity of expressing the technical solution and the convenience of description. Therefore, it should not be construed as a limitation to the present invention.

[0077] In this text, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion. In addition to including the listed elements, it may also include other elements not specifically listed.

[0078] The above are only the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. Tubular interval charging structure, characterized in that: It includes a shaped charge tube (100) inserted closely against the inner wall of the blast hole and explosive segments (200) filled in the shaped charge tube at intervals in sections; On the inner side wall of the shaped charge tube (100) corresponding to the explosive segments, there is a shaped charge cone (101) facing the center of the tube. The side of the explosive in the explosive segment (200) is shaped by the shaped charge cone to form an outward-shaped charge cavity (201); On the side wall of the shaped charge cone (101) in contact with the explosive segment, there is a metal powder layer (102).

2. The tubular spaced charge structure according to claim 1, wherein: Several groups of the shaped charge cones (101) are axially distributed along the inner wall of the shaped charge tube on both sides of the explosive segment. The circumferential orientation of the shaped charge cones distributed axially in the shaped charge tube is aligned with the orientation of the line connecting the blast hole where they are located and the adjacent blast holes. The groups of the shaped charge cones (101) on the same axis are evenly distributed at equal intervals; 3. The tubular spaced charge structure according to claim 2, characterized in that: The total area of the bottoms of all the shaped charge cones (101) accounts for 15 - 25% of the surface area of the inner side wall of the shaped charge tube (100).

4. The tubular spaced charge structure according to claim 1, wherein: The metal powder layer (102) is a copper powder layer sprayed on the surface of the shaped charge cone; 5. The tubular spaced charge structure according to claim 1, characterized in that: The shaped charge tube (100) uses a PVC tube with a pore diameter of 80 - 90% of the outer diameter. The PVC tube is provided with a grounding conductive silica gel connecting the inner wall and the surrounding rock of the blast hole; 6. The tubular spaced charge structure according to claim 1, characterized in that: The outer wall of the shaped charge tube (100) is sprayed with an Al2O3 - ZrO2 composite ceramic coating; 7. The tubular spaced charge structure according to claim 1, wherein: An air spacer (400) is arranged between the explosive segments (200) to enable the explosive segments to be arranged in sections in the shaped charge tube. A stemming section (300) is arranged at the top of the shaped charge tube close to the blast hole outlet to seal the charging structure in the shaped charge tube. All the explosive segments (200) are connected to the initiation network through electronic detonators (500); 8. The tubular spaced charge structure according to claim 7, characterized in that: The explosive segments are filled with bulk explosives into the tube sections of the shaped charge tube (100) corresponding to the shaped charge cones. Among them, emulsion explosives are used for hard rock around the blast hole, and ammonium fuel oil explosives are used for mudstone around the blast hole; 9. A blasting method using a tubular interval charging structure, characterized in that: It includes the following steps: Step 1: Explore and demarcate the blasting area, investigate the geological conditions of the area, and determine the hole layout parameters according to the ore body lithology, structural characteristics and blasting objectives; Step 2: Use a drill to drill holes according to the hole layout parameters and maintain the blast holes; Step 3: Prefabricate the shaped charge tube used in the tubular interval charging structure of Claims 1 - 8. The inner side wall of the shaped charge tube is processed with a shaped charge cone facing the center of the tube. The circumferential orientation of the shaped charge cones distributed axially in the shaped charge tube is aligned with the orientation of the line connecting the blast hole where they are located and the adjacent blast holes. Spray copper powder on the surface of the shaped charge cones in the shaped charge tube to form a metal powder layer. Spray an Al2O3 - ZrO2 composite ceramic coating on the outer wall of the shaped charge tube. Insert the prefabricated shaped charge tube into the blast hole. When installing the shaped charge tube, select the corresponding shaped charge tube according to the hole layout plan between the blast holes and align the orientation of the shaped charge cones arranged on it with the orientation of the line connecting the adjacent blast holes; Step 4: Fill the explosive segments and electronic detonators into the shaped charge tube at intervals in sections according to the tubular interval charging structure of Claims 1 - 8. The segmented explosive segments correspond to the areas where the shaped charge cones are located in the shaped charge tube; Step 5: Connect the electronic detonators in all the blast holes through wires to form a delay initiation network, and seal the blast holes tightly with stemming; Step 6: Initiate. After the blasting is completed, collect the images of the muck pile, and use the WipFrag digital image analysis system to statistically analyze the fragment size distribution.

10. A blasting method using a tubular interval charging structure according to claim 9, characterized in that: The delays of the delay initiation network include the in-hole delay and the between-row delay, and the calculation formula for the delay time Δt is as follows: ， where: w is the single-hole charge of explosive, V p is the blasting wave velocity, K1 is the empirical correction factor, W is the energy required for blasting, C p is the specific heat capacity of the rock, S is the hole spacing, and V is the volume of the blasting area.

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