A structure and method for arranging upward first blasting groove holes in a natural caving method

Abstract

The application discloses a blasting hole arrangement structure and method for a first upward blasting groove in a natural caving method. The cutting roadway of the blasting hole arrangement structure extends to both sides through the middle of the mining roadway, and a plurality of fan-shaped cutting holes with a center angle are arranged on the roof of the cutting roadway, with the center angle being raised and staggered from hole to hole. A plurality of upward vertical cutting holes are arranged on the roof of the middle of the cutting roadway, with the length of the vertical cutting holes being gradually shortened from the center of the mining roadway to both sides and arranged below the fan-shaped cutting holes staggered on both sides. The first blasting groove method comprises the steps of mining and cutting roadway excavation, blasting hole arrangement, drilling, delay control, initiation of the explosive package arrangement, blasting hole filling, and initiation. The blasting hole arrangement structure is simple, and it is not necessary to dig large holes to form a cutting shaft, nor is it necessary to blast multiple times, so that the first blasting groove can be realized without a shaft, the construction efficiency is improved, the labor intensity is reduced, and the construction cost and safety risk are reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of blasting engineering, and particularly relates to a structure and method of a simple, efficient, low-labor, low-cost and safe upward one-time blasting slotting blasthole arrangement for a natural caving method. BACKGROUND

[0002] For a natural caving method mine with relatively stable ore and rock, a "cutting drift + cutting raise" or "cutting raise + fan-shaped blasthole" method is usually used to form a cutting slot. The "cutting drift + cutting raise" slotting method is to first construct a cutting drift at the end of the access, then construct a cutting raise upward in the cutting drift, then construct an upward blasthole row parallel to the cutting raise in the cutting drift, and finally form a cutting slot with the cutting raise as the blasting compensation space. The "cutting raise + fan-shaped blasthole" slotting scheme is to first form a cutting raise at the end of the access, then arrange fan-shaped blastholes on both sides of the cutting raise, and form a cutting slot with the cutting raise as the blasting compensation space when slotting.

[0003] As can be seen, the formation of the cutting raise is the most important and key in the above-mentioned slotting scheme. As long as a qualified cutting raise is formed, a cutting slot can generally be formed as expected. However, the existing "first form a cutting raise, then form a cutting slot" slotting scheme has the disadvantages of low operation efficiency, poor slotting effect, poor safety, etc., and cannot meet the requirements of rapid and safe slotting construction of the cutting slot. Although the use of a raise drill can avoid the problems of poor safety and low efficiency, it will also result in high construction cost, and is difficult to popularize in mines due to the requirement of rock firmness coefficient.

[0004] In addition, the formation of the cutting raise requires two blasting for well expansion and slot expansion to form a cutting slot. For an upward cutting raise, there is only one free surface at the lower opening position without a connected engineering at the upper part, it is difficult to implement one-time well-forming segmented charging and blasting, and the blasthole arrangement is easily affected by the drilling accuracy of the drill, resulting in poor blasting effect and limited height during one-time well-forming.

[0005] That is, in the existing cutting slot slotting technology, there are technical defects such as multi-stage slotting, high labor intensity, low efficiency, poor safety, etc. Therefore, in view of the above technical problems and defects, it is urgent to design and develop an upward non-raise one-time blasting slotting blasthole arrangement structure and method for a natural caving method. SUMMARY

[0006] According to the deficiencies of the prior art, the natural caving method upward one-time blasting slotting hole arrangement structure with simple hole arrangement, high construction efficiency, low labor intensity, low construction cost and low safety risk is provided, and a one-time blasting slotting method based on the natural caving method upward one-time blasting slotting hole arrangement structure is also provided.

[0007] The natural caving method upward one-time blasting slotting hole arrangement structure is achieved as follows: comprising a mining roadway and a cutting roadway, the cutting roadway extends through the middle of the mining roadway and extends to both sides, a plurality of fan-shaped slotting holes are arranged on the roof of the cutting roadway on both sides of the mining roadway in the longitudinal direction, the angle of the fan-shaped slotting holes is increased hole by hole and the fan-shaped slotting holes are arranged staggeredly on both sides, a plurality of upward vertical slotting holes are arranged on the roof of the cutting roadway at the intersection with the mining roadway in the longitudinal direction, the length of the vertical slotting holes on the roof of the cutting roadway is gradually shortened from the center of the mining roadway to both sides of the cutting roadway, and the vertical slotting holes on the roof of the cutting roadway are arranged below the fan-shaped slotting holes arranged staggeredly on both sides.

[0008] The one-time blasting slotting method based on the natural caving method upward one-time blasting slotting hole arrangement structure is achieved as follows: comprising mining and cutting roadway excavation, hole arrangement, drilling, delay control, detonating charge arrangement, hole filling, and detonation steps, and the specific steps are as follows:

[0009] A. Mining and cutting roadway excavation: excavating a straight-through mining roadway from two approaches, and excavating cutting roadways to both sides in the middle of the mining roadway;

[0010] B. Hole arrangement: removing float stones and uneven rocks in the cutting roadway, arranging upward vertical slotting holes with the center line of the mining roadway as the axis, and arranging fan-shaped slotting holes in the cutting roadways on both sides and making the angle of the fan-shaped slotting holes on both sides increase hole by hole and staggered arrangement;

[0011] C. Drilling: drilling the fan-shaped slotting holes and the vertical slotting holes according to the hole arrangement of step B, and the hole diameter is 75-80 cm when the hole depth is less than 10 m, and the hole diameter is 88-93 cm in the middle two rows of even rows and the center row of odd rows when the hole depth is greater than or equal to 10 m, and the hole diameter of the remaining rows is 75-80 cm;

[0012] D. Delay control: hole-by-hole detonation of the charge in the fan-shaped slotting holes and the vertical slotting holes, and the delay time between holes is 4-6 ms and the delay time between rows is 0-100 ms;

[0013] E. Detonating charge arrangement: upward filling of the explosives in the fan-shaped slotting holes and the vertical slotting holes to the hole bottom, and one detonating charge is placed on the top and the bottom of the explosives, and a digital electronic detonator is embedded in the detonating charge;

[0014] F. Hole filling: For fan-shaped cut holes and vertical cut holes, continuous coupled charging is used. For fan-shaped cut holes with a depth ≥10m, the charging length is 3.5 to 4.5m and for holes with a depth <10m, the charging length is 1.5 to 2.5m. For vertical cut holes, the charging length is 0.3 to 0.7m.

[0015] G. Detonation: Control the delay according to step D. First, the vertical cut holes are detonated, then the fan-shaped cut holes are detonated, and each row is detonated one hole at a time. The middle two rows or the center row of the fan-shaped cut holes and vertical cut holes are detonated first.

[0016] The beneficial effects of this invention are:

[0017] 1. The single-blasting slotting borehole arrangement structure of this invention forms a wedge-shaped slotting borehole structure by arranging vertical slotting holes and fan-shaped slotting holes on both sides. The fan-shaped slotting holes are constructed at both ends of the cutting tunnel, and the blasting delay of each hole is cleverly designed, thus forming a cutting groove in a single blast. Compared to the traditional slotting blasting structure, which requires drilling a large borehole first, then drilling enlargement boreholes, and finally drilling additional slotting boreholes, this invention shortens construction time, reduces drilling costs, and ensures drilling accuracy, thereby simplifying the process. The invention streamlines the drilling process; and compared to the traditional slotting structure, which requires two charging operations—first installing the well-enlarging blast holes and then the slot-enlarging blast holes—this invention only requires one charging operation, greatly simplifying the charging process for blasting and slotting. Compared to the traditional slotting scheme of "first forming the cutting well, then forming the cutting vertical slot," which requires one ore extraction after well formation and another after slot formation, this invention allows ore extraction after slot formation, which can improve construction efficiency by 15-30%, reduce the labor intensity of workers, and also reduce construction costs and safety risks.

[0018] 2. The single-stage blasting trenching method of the present invention, compared with existing methods that do not drill a large central hole and do not perform well-enlargement blasting, lacks a free surface and compensation space for blasting. To address this, multiple rows of fan-shaped and vertical slotting holes are arranged, and a technique of sequential blasting with delayed blasting between holes and rows is adopted. The slotting holes in the middle two rows or the central row are blasted first to provide a certain compensation space for the blasting of subsequent blast holes. Then, the other rows are blasted to expand the trench cavity until the cutting trench designed for blasting is formed. This makes the subsequent blast holes equivalent to compression blasting, which greatly improves the success rate of single-stage blasting trenching. The combination of compression blasting optimizes the utilization of compensation space for blasting, expands the blastable range of the cutting trench, and provides a larger free surface for subsequent blasting to form aggregate trenches. Compared with the traditional trenching scheme, the blasted particles are more fragmented overall, and the large piece rate can be reduced by 30-50%, improving the economy of trenching blasting.

[0019] In summary, the present invention features simple borehole layout, high construction efficiency, low labor intensity, low construction cost, and low safety risk. Attached Figure Description

[0020] Figure 1 This is a schematic plan view of an embodiment of the blasting trenching borehole arrangement structure of the present invention;

[0021] Figure 2 This is a three-dimensional structural schematic diagram of an embodiment of the blasting trenching borehole arrangement structure of the present invention;

[0022] Figure 3 for Figure 2 A frontal view of the structure;

[0023] Figure 4 for Figure 3 Left view;

[0024] Figure 5 for Figure 3 MM-oriented view;

[0025] Figure 6 This is a schematic diagram of the charge structure of the present invention;

[0026] In the diagram: 1-mine exit tunnel, 2-cutting tunnel, 3-fan-shaped slotting hole, 4-vertical slotting hole, 5-cutting groove, 6-explosive, 7-detonating charge, 8-digital electronic detonator, 9-access route, 10-blasting mud, 11-hole sealing. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this does not limit the present invention in any way. Any changes or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.

[0028] like Figures 1 to 6 As shown, the upward primary blasting trenching hole arrangement structure in the natural caving method of the present invention includes an ore extraction level 1 and a cutting level 2. The cutting level 2 penetrates the middle of the ore extraction level 1 and extends to both sides. On the top plate of the cutting level 2 on both sides of the ore extraction level 1, there are several fan-shaped slotting holes 3 arranged longitudinally, which are raised from the center angle of the ore extraction level 1 and are staggered on both sides. On the top plate of the cutting level 2 at the part where it intersects with the ore extraction level 1, there are also several upward vertical slotting holes 4 arranged longitudinally. The length of the vertical slotting holes 4 on the top plate of the cutting level 2 is gradually shortened from the center of the ore extraction level 1 to both sides of the cutting level 2. The vertical slotting holes 4 on the top plate of the cutting level 2 are arranged below the fan-shaped slotting holes 3 arranged staggered on both sides.

[0029] The fan-shaped slotting holes 3 and vertical slotting holes 4 on the top plate of the cutting level 2 are arranged symmetrically with the center line of the cutting level 2 in the transverse direction, and there are 3 to 6 rows. When the number of rows of the fan-shaped slotting holes 3 and vertical slotting holes 4 is odd, they are arranged symmetrically with the central row that coincides with the center line of the cutting level 2 and the row spacing is 1.0 to 1.2m. When the number of rows is even, they are arranged symmetrically with the center line of the cutting level 2 and the row spacing of the middle two rows is 0.5 to 0.8m, and the row spacing of the other rows is 1.0 to 1.4m.

[0030] The fan-shaped slotted hole 3 and the vertical slotted hole 4 are respectively loaded with continuously coupled explosives. If the depth of the fan-shaped slotted hole 3 is ≥10m, the explosive is filled with a length of 3.5 to 4.5m, and if the depth is <10m, the explosive is filled with a length of 1.5 to 2.5m. The explosive in the vertical slotted hole 4 is filled with a length of 0.3 to 0.7m.

[0031] The charge in the fan-shaped cutout hole 3 and the vertical cutout hole 4 is detonated hole by hole with an inter-hole delay of 4-6 ms and an inter-row delay of 0-100 ms.

[0032] If the depth of the fan-shaped slotted hole 3 and the vertical slotted hole 4 is less than 10m, the hole diameter is 75-80cm. If the depth is greater than or equal to 10m, the hole diameter of the middle two rows of even-numbered rows and the center row of odd-numbered rows is 88-93cm, and the hole diameter of the remaining rows is 75-80cm.

[0033] In the fan-shaped slotting holes 3 and vertical slotting holes 4, the detonation is delayed from the middle two rows or the center row symmetrical to the center line of the cutting lane 2 outwards. When the corresponding holes of the two rows symmetrical to the center line of the cutting lane 2 have no delay and the width of the cutting slot 5 is ≤3m, the inter-row delay of other rows is ≥50ms; when the width is >3m, the inter-row delay of other rows is ≥80ms.

[0034] The corresponding holes in the vertical slotting holes 4 that are symmetrical about the center line of the ore extraction tunnel 1 have no time delay.

[0035] The explosives 6 in the fan-shaped slotted holes 3 and the vertical slotted holes 4 are filled upwards to the bottom of the holes, and a detonating charge 7 is placed at the top and bottom of the explosives 6. A digital electronic detonator 8 is embedded in the detonating charge 7.

[0036] This invention relates to a one-stage blasting trenching method based on the upward single-stage blasting trenching borehole arrangement structure in the natural caving method. The method includes the following steps: ore extraction and cutting level tunnel excavation, borehole arrangement, drilling, delay control, detonation charge arrangement, borehole filling, and detonation. The specific steps are as follows:

[0037] A. Mining and cutting tunnel excavation: Mining tunnel 1 is excavated from the two access routes to form a straight tunnel 1. Cutting tunnel 2 is formed by excavating from the middle of mining tunnel 1 to both sides.

[0038] B. Arrangement of blast holes: Remove loose rocks and uneven rocks from the cutting tunnel 2, arrange vertical blast holes 4 with the center line of the mining tunnel 1 as the axis, and arrange fan-shaped blast holes 3 on both sides of the cutting tunnel 2, and make the angle of the fan-shaped blast holes 3 on both sides increase one hole at a time and arrange them in an alternating manner.

[0039] C. Drilling: Drill fan-shaped slotted holes 3 and vertical slotted holes 4 according to the blast hole layout in step B. If the hole depth is <10m, the hole diameter is 75-80cm. If the hole depth is ≥10m, the hole diameter of the middle two rows of even-numbered rows and the center row of odd-numbered rows is 88-93cm, and the hole diameter of the remaining rows is 75-80cm.

[0040] D. Delay control: The charges in the fan-shaped cut holes 3 and the vertical cut holes 4 are detonated one hole at a time with a delay of 4-6ms between holes and 0-100ms between rows.

[0041] E. Arrangement of detonating charge: The explosive 6 in the fan-shaped slot 3 and the vertical slot 4 is filled upward to the bottom of the hole, and a detonating charge roll 7 is placed at the top and bottom of the explosive 6. A digital electronic detonator 8 is embedded in the detonating charge roll 7.

[0042] F. Hole filling: The fan-shaped cut hole 3 and the vertical cut hole 4 are filled with continuous coupled explosive charges. If the depth of the fan-shaped cut hole 3 is ≥10m, the explosive charge is filled with a length of 3.5 to 4.5m and if the depth is <10m, the explosive charge is filled with a length of 1.5 to 2.5m. The explosive charge of the vertical cut hole 4 is filled with a length of 0.3 to 0.7m.

[0043] G. Detonation: Control the delay according to step D. First, the vertical cut hole 4 is detonated, then the fan-shaped cut hole 3 is detonated, and each row is detonated one hole at a time. The middle two rows or the center row of the fan-shaped cut hole 3 and the vertical cut hole 4 are detonated first.

[0044] In step B, the fan-shaped slotting holes 3 and vertical slotting holes 4 on the top plate of the cutting level 2 are arranged symmetrically with the center line of the cutting level 2 in the transverse direction, with 3 to 6 rows. When the number of rows of fan-shaped slotting holes 3 and vertical slotting holes 4 is odd, they are arranged symmetrically with the central row that coincides with the center line of the cutting level 2 and the row spacing is 1.0 to 1.2m. When the number of rows is even, they are arranged symmetrically with the center line of the cutting level 2 and the row spacing of the middle two rows is 0.5 to 0.8m, and the row spacing of the other rows is 1.0 to 1.4m.

[0045] In step D, the fan-shaped slotting holes 3 and vertical slotting holes 4 are detonated with a delay from the middle two rows or the center row symmetrical to the center line of the cutting lane 2 outwards. When the corresponding holes of the two rows symmetrical to the center line of the cutting lane 2 have no delay and the width of the cutting slot 5 is ≤3m, the inter-row delay of other rows is ≥50ms; when the width is >3m, the inter-row delay of other rows is ≥80ms.

[0046] In step G, the vertical slotting holes 4 are detonated gradually from both sides of the ore extraction tunnel 1 toward the center with a time delay, and the two rows of holes that are centrally symmetrical are detonated without a time delay. The fan-shaped slotting holes 3 arranged alternately on both sides of the ore extraction tunnel 1 are detonated gradually upward from the lowest end closest to the vertical slotting holes 4 with a time delay.

[0047] In step C, the skewness of each hole in the fan-shaped slot 3 and the vertical slot 4 is ≤1%.

[0048] Example 1

[0049] like Figures 1 to 6 As shown, taking a cutting trench in an underground mine in Yunnan with a design height of 16m and a width of 3m as an example, the fan-shaped cut holes 3 on both sides of the ore extraction tunnel 1 are numbered H10~H21 along the longitudinal direction, and the vertical cut holes 4 are numbered H5~H9; the fan-shaped cut holes 3 and the vertical cut holes 4 are arranged symmetrically with the center line of the cutting tunnel 2 in 4 rows along the transverse direction and are numbered R1~R4. The specific process is as follows:

[0050] S100: A straight, through-passage mining tunnel 1 is excavated from the two access routes 9, and a cutting tunnel 2 is formed by excavating from the middle of the mining tunnel 1 to both sides.

[0051] S200: Remove loose rocks and uneven rocks from the cutting tunnel 2. Arrange upward vertical cut holes 4 numbered H5 to H9 with the center line of the cutting tunnel 2 as the axis, with a hole spacing of 1.2m. The distance between the blast holes H8 and H9 and the far end of the cutting tunnel 2 is 4.1m. Then arrange fan-shaped cut holes 3 numbered H10 to H21 on both sides of the cutting tunnel 2, and raise the angle of the fan-shaped cut holes 3 on both sides one by one and arrange them in an alternating manner. The spacing between R1 and R2 of the fan-shaped cut holes 3 and the vertical cut holes 4 is 0.6m, and the spacing between R1 and R3 and between R2 and R4 is 1.2m.

[0052] S300: As described above, use a rock drilling rig to drill vertical cut holes 4 from H5 to H9 and fan-shaped cut holes 3 from H10 to H21, in four rows (R1 to R4). Using the centerline of the ore extraction level 1 as the axis, first drill the upward vertical cut holes 4 in the middle of the cutting level 2 with a diameter of 78mm, where the hole depths of H5 to H9 are 1.5m, 2.8m, 4.8m, 2.8m, and 1.5m respectively. Then, on the outer sides of the cutting level 2 on both sides of the ore extraction level 1, drill the fan-shaped cut holes 3 from H10 to H21 in rows with a hole depth <10m and a diameter of 78mm for rows with a hole depth ≥10m, and drill the remaining rows with a diameter of 78mm for rows H10 to H21. The deviation rate of the cut holes from H5 to H9 and H10 to H21 is ≤1%.

[0053] S400: The time delay between each borehole in rows R1 to R4 of the fan-shaped cut-out holes 3 and the vertical cut-out holes 4 is 5ms, that is, H8 and H9 have a time delay of 0ms, H6 and H7 have a time delay of 5ms, H5 has a time delay of 10ms, H10 has a time delay of 15ms, H11 has a time delay of 20ms, H12 has a time delay of 25ms, H13 has a time delay of 30ms, H14 has a time delay of 35ms, H15 has a time delay of 40ms, H16 has a time delay of 45ms, H17 has a time delay of 50ms, H18 has a time delay of 55ms, H19 has a time delay of 60ms, H20 has a time delay of 65ms, and H21 has a time delay of 70ms; among them, there is no time delay between the corresponding holes in each row of R1 and R2 and R3 and R4 and they are detonated simultaneously.

[0054] S500: The explosive 6 in the fan-shaped cut hole 3 and the vertical cut hole 4 is filled upward to the bottom of the hole, and a detonating charge 7 is placed at the top and bottom of the explosive 6. A digital electronic detonator 8 is embedded in the detonating charge 7. The explosive 6 is a granular sticky ammonium nitrate explosive.

[0055] S600: The fan-shaped cut hole 3 and the vertical cut hole 4 are respectively continuously coupled with explosives. If the depth of the fan-shaped cut hole 3 is ≥10m, the explosives are filled with a length of 3.5m and if the depth is <10m, the explosives are filled with a length of 1.5m. The explosives in the vertical cut hole 4 are filled with a length of 0.5m.

[0056] S700: According to the delay in S400, the vertical cut hole 4 is detonated first, followed by the fan-shaped cut hole 3, and each row is detonated one hole at a time. The fan-shaped cut hole 3 and the vertical cut hole 4 are detonated first in the middle two rows symmetrical to the center line of the cutting level 2.

[0057] The effect of blasting trenching: The traditional trenching method of "first forming a cutting well, then forming a cutting trench" requires a large amount of ore extraction because the cutting well is horizontally connected to the bottom of the trench. Furthermore, construction workers must work under the already blasted cutting well, resulting in a very poor working environment and compromised safety. This invention's one-time blasting trenching increases construction safety, reduces auxiliary work time, accelerates the construction progress of the ore-gathering trench, shortens the preparation time for the ore outlet, and ensures timely ore production. This improves labor productivity, reduces production costs, and simplifies the operation process. Preliminary observations of the embodiments show that, compared with traditional trenching, the one-time blasting trenching method using the ore-gathering trench and cutting trench, when observed during the trenching process, did not show serious damage to the surrounding blast holes and access routes. The ore piles from the trenching collapse were relatively concentrated, with virtually no scattered flyrock around. The size of the collapsed ore pieces was mainly concentrated between 0.3 and 0.6 mm, with virtually no large pieces exceeding 0.6 mm, reducing the large piece rate by 30%. Using a loader to remove the ore, further observation revealed a well-formed cutting groove cavity. The cavity extended from bottom to top, with no overhanging roof on the east and west sides. The roof height met the blasting design requirements. The middle of the cutting groove connected to the upper section of the drilling roadway without any overhanging roof. The blast face was neat, and the groove wall was smooth, facilitating the next stage of forward blasting. The overall cutting groove blasting effect was good, meeting the engineering blasting requirements. Furthermore, blasting vibration monitoring showed that the maximum vibration velocity generated by this slotting blasting was 1.6 cm / s at the monitoring point in the caving method stope (125m from the blast center) and 0.44 cm / s at the monitoring point in the upper horizontal stope (250m from the blast center), both below the safe allowable values ​​for blasting vibration velocity specified in the "Blasting Safety Regulations." This example demonstrates that this method has a series of advantages, including simple process, safety and reliability, and high slotting efficiency.

[0058] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A structure for arranging boreholes in an upward primary blasting trench formation using a natural caving method, characterized in that... The system includes a mining tunnel (1) and a cutting tunnel (2). The cutting tunnel (2) runs through the middle of the mining tunnel (1) and extends to both sides. On the top plate of the cutting tunnel (2) on both sides of the mining tunnel (1), there are several fan-shaped slotting holes (3) that are raised from the center angle of the mining tunnel (1) and are staggered on both sides. On the top plate of the cutting tunnel (2) where it intersects with the mining tunnel (1), there are also several upward vertical slotting holes (4) along the longitudinal direction. The length of the vertical slotting holes (4) on the top plate of the cutting tunnel (2) is gradually shortened from the center of the mining tunnel (1) to the cutting tunnel (2) on both sides. The vertical slotting holes (4) on the top plate of the cutting tunnel (2) are arranged below the fan-shaped slotting holes (3) that are staggered on both sides. The fan-shaped slotting holes (3) and vertical slotting holes (4) on the top plate of the cutting level (2) are arranged symmetrically with the center line of the cutting level (2) in the transverse direction, and there are 3 to 6 rows. When the number of fan-shaped slotting holes (3) and vertical slotting holes (4) is odd, they are arranged symmetrically with the central row that coincides with the center line of the cutting level (2) and the row spacing is 1.0 to 1.2m. When the number of rows is even, they are arranged symmetrically with the center line of the cutting level (2) and the row spacing of the middle two rows is 0.5 to 0.8m, and the row spacing of the other rows is 1.0 to 1.4m. The fan-shaped slotted hole (3) and the vertical slotted hole (4) are respectively continuously coupled with explosives. If the depth of the fan-shaped slotted hole (3) is ≥10m, the explosives are filled with a length of 3.5 to 4.5m and if the depth is <10m, the explosives are filled with a length of 1.5 to 2.5m. The explosives in the vertical slotted hole (4) are filled with a length of 0.3 to 0.7m. The charge in the fan-shaped slotted hole (3) and the vertical slotted hole (4) is detonated hole by hole with a delay of 4-6 ms between holes and a delay of 0-100 ms between rows. If the depth of the fan-shaped slotted hole (3) and the vertical slotted hole (4) is <10m, the hole diameter is 75-80cm. If the depth of the hole is ≥10m, the hole diameter of the middle two rows of even-numbered rows and the center row of odd-numbered rows is 88-93cm, and the hole diameter of the remaining rows is 75-80cm. In the fan-shaped slotting hole (3) and the vertical slotting hole (4), the two middle rows or the central row symmetrical to the center line of the cutting lane (2) are detonated with a delay. When the corresponding holes of the two rows symmetrical to the center line of the cutting lane (2) have no delay and the width of the cutting slot (5) is ≤3m, the inter-row delay of other rows is ≥50ms. When the width is >3m, the inter-row delay of other rows is ≥80ms.

2. The upward primary blasting trenching borehole arrangement structure in the natural caving method according to claim 1, characterized in that... The explosives (6) in the fan-shaped slotted hole (3) and the vertical slotted hole (4) are filled upwards to the bottom of the hole, and a detonating charge (7) is placed at the top and bottom of the explosives (6). A digital electronic detonator (8) is embedded in the detonating charge (7).

3. A method for primary blasting trenching based on the upward primary blasting trenching borehole arrangement structure in the natural caving method as described in claim 1 or 2, characterized in that... This includes ore extraction and cutting tunnel excavation, borehole layout, drilling, delay control, detonation charge placement, borehole filling, and detonation procedures. The specific steps are as follows: A. Mining and cutting tunnel excavation: A straight mining tunnel (1) is excavated from the two access routes, and a cutting tunnel (2) is formed by excavating from the middle of the mining tunnel (1) to both sides. B. Arrangement of blast holes: Remove loose rocks and uneven rocks from the cutting tunnel (2), arrange vertical blast holes (4) facing upward with the center line of the mining tunnel (1) as the axis, and arrange fan-shaped blast holes (3) on both sides of the cutting tunnel (2) and make the angle of the fan-shaped blast holes (3) on both sides increase one hole at a time and arrange them in an alternating manner. C. Drilling: Drill fan-shaped slotted holes (3) and vertical slotted holes (4) according to the blast hole layout in step B. If the hole depth is <10m, the hole diameter is 75-80cm. If the hole depth is ≥10m, the hole diameter of the middle two rows of even-numbered rows and the center row of odd-numbered rows is 88-93cm, and the hole diameter of the remaining rows is 75-80cm. D. Delay control: The charge of the fan-shaped slotted hole (3) and the vertical slotted hole (4) is detonated hole by hole with a delay of 4-6ms between holes and a delay of 0-100ms between rows; E. Arrangement of detonating charge: The explosives (6) in the fan-shaped slotted hole (3) and the vertical slotted hole (4) are filled upward to the bottom of the hole, and a detonating charge roll (7) is placed at the top and bottom of the explosives (6). A digital electronic detonator (8) is embedded in the detonating charge roll (7). F. Filling the blast holes: The fan-shaped cut holes (3) and the vertical cut holes (4) are filled with continuous coupled charges. If the depth of the fan-shaped cut holes (3) is ≥10m, the charge is filled with a length of 3.5 to 4.5m and if the depth is <10m, the charge is filled with a length of 1.5 to 2.5m. The charge of the vertical cut holes (4) is filled with a length of 0.3 to 0.7m. G. Detonation: Control the delay according to step D. First, the vertical slotting hole (4) is detonated, then the fan-shaped slotting hole (3) is detonated, and each row is detonated one hole at a time. The middle two rows or the center row of the fan-shaped slotting hole (3) and the vertical slotting hole (4) are detonated first.

4. The upward single-stage blasting trenching method in the natural caving method according to claim 3, characterized in that... In step B, the fan-shaped slotting holes (3) and vertical slotting holes (4) on the top plate of the cutting tunnel (2) are arranged symmetrically with respect to the center line of the cutting tunnel (2) in the transverse direction, with 3 to 6 rows. When the number of fan-shaped slotting holes (3) and vertical slotting holes (4) is odd, they are arranged symmetrically with the central row coinciding with the center line of the cutting tunnel (2) and the row spacing is 1.0 to 1.2 m. When the number of rows is even, they are arranged symmetrically with respect to the center line of the cutting tunnel (2) and the row spacing between the two middle rows is 0.5 to 1.2 m. 0.8m, the row spacing of other rows is 1.0~1.4m; in the fan-shaped slotting hole (3) and vertical slotting hole (4) of step D, the middle two rows or the central row symmetrical to the center line of the cutting lane (2) are detonated with a delay from the outer row, so that the corresponding holes of the two rows symmetrical to the center line of the cutting lane (2) have no delay and the width of the cutting groove (5) is ≤3m, the row delay of other rows is ≥50ms, and the row delay of other rows is ≥80ms when the width is >3m.

5. The upward single-stage blasting trenching method in the natural caving method according to claim 3, characterized in that... In step G, the vertical slotting holes (4) are detonated gradually from both sides of the ore extraction tunnel (1) toward the center with a delay, and the two rows of holes that are centrally symmetrical are detonated without a delay. The fan-shaped slotting holes (3) arranged alternately on both sides of the ore extraction tunnel (1) are detonated gradually from the lowest end near the vertical slotting holes (4) upwards with a delay.

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