Method for forming groove by once blasting of medium-length hole

Abstract

This application provides a method for creating a trench using a single-stage blasting technique for medium-deep holes, relating to the field of mining technology. The method includes: determining the layout and structural parameters of the drilling tunnel, cutting cross passage, and cutting trench; determining the fragmentation coefficient based on the type of ore and the size of the crushed ore blocks, and estimating the required compensation space; if the required compensation space is less than the space of the cutting cross passage, proceeding to the next step; constructing the drilling tunnel along the mining direction at the bottom of the mining area to the mining boundary; according to the cutting engineering layout plan, excavating from the drilling tunnel to both sides of the mining area to the sidewall boundary to form the cutting cross passage; dividing the top of the cutting cross passage into a slotting zone and a widening zone, and arranging upward fan-shaped medium-deep holes in the slotting zone and upward parallel medium-deep holes in the widening zone; performing a single-stage charge on the upward fan-shaped and upward parallel medium-deep holes in the cutting cross passage; and implementing zoned micro-delay blasting after the charge is completed. This application achieves trench creation through a single-stage blasting technique, improving safety and stability.

Description

Technical Field

[0001] This application relates to the field of mining, and more specifically, to a method for creating trenches using a single blasting method for medium-deep holes. Background Technology

[0002] In underground mining, the cutting trench provides compensation space and an initial free face for large-scale caving in the stope. Its construction quality directly affects the efficiency and safety of the entire subsequent mining operation. Currently, the cutting trench is commonly formed using the cutting raise method in the mining industry. This method typically involves first constructing a vertical or inclined cutting raise to create an initial free face, followed by multiple blasts to gradually expand and form the cutting trench. However, the construction of the cutting raise involves multiple processes such as rock drilling, charging, and ventilation, resulting in a long overall construction cycle and low efficiency. Furthermore, due to the strong clamping effect on the ore and rock above the cutting raise, a suspended roof phenomenon is prone to occur after blasting, affecting the smooth progress of subsequent operations. More critically, the single charge during cutting raise blasting typically reaches several tons, and the huge blast shock wave can significantly disturb surrounding existing blast holes, inducing the development of hole wall fissures or even hole collapse. This not only increases the construction difficulty but also creates safety hazards for subsequent mining operations. Summary of the Invention

[0003] The purpose of this application is to provide a method for one-time blasting trenching in medium-deep holes, which can realize one-time blasting trenching, avoid the need for personnel and equipment to be frequently exposed to the edge of the formed goaf, improve the inherent safety level of the mining process, and effectively ensure the formation of the trench.

[0004] This invention provides a method for creating trenches in medium-deep holes using a single blasting operation, comprising: Based on the mining and cutting engineering design plan, determine the layout and structural parameters of the drilling tunnels, cutting cross tunnels, and cutting slots; Based on the type of ore and the size of the crushed ore, determine the crushing expansion coefficient and estimate the required compensation space. If the required compensation space is less than the space for cutting the transverse tunnel, proceed to the next step. At the bottom of the mining area, the rock drilling tunnel is constructed along the mining area direction to the mining area boundary. According to the cutting project layout plan, the rock drilling tunnel is excavated from the rock drilling tunnel to both sides of the mining area to the side wall boundary to form a cutting cross tunnel. The cutting cross tunnel serves as the working site for rock drilling and charging of cutting slot blast holes and the compensation space for blasting and falling ore. The top of the cutting cross passage is divided into a slotting area and a widening area. Upward fan-shaped medium-deep holes are arranged in the slotting area, and upward parallel medium-deep holes are arranged in the widening area. The upward fan-shaped medium-deep hole and the upward parallel medium-deep hole are loaded with explosives in a single operation within the cutting transverse tunnel; After the explosive charge is completed, all boreholes in the entire cutting groove area are subjected to zonal micro-delay blasting. First, the upward fan-shaped medium-deep holes are blasted layer by layer from bottom to top, with the bottom cutting cross passage as the free surface and compensation space. Then, the upward parallel medium-deep holes are blasted with the slotting area and the bottom cutting cross passage as the free surface and compensation space.

[0005] In an optional embodiment, the slotted area is arranged with multiple rows of upward fan-shaped deep holes, each row of upward fan-shaped deep holes is formed by multiple inclined holes arranged in a fan shape, and the inclined holes of different rows with the same angle are divided into a layer.

[0006] In an optional implementation, the inclined holes located on the same layer are treated as a single blasting section.

[0007] In an optional implementation, the upward fan-shaped deep holes are detonated layer by layer in a bottom-up sequence, allowing the blast free surface to expand upward.

[0008] In an optional embodiment, the expansion groove area is arranged with multiple rows of upward parallel medium-deep holes, and each row of upward parallel medium-deep holes is formed by multiple vertical holes arranged in parallel.

[0009] In an optional implementation, each of the vertical holes in each row is considered as a blasting section.

[0010] In an optional implementation, the number of expansion zones is two sets, with the two sets of expansion zones arranged on both sides of the slotting zone, and the slotting zone arranged on the central axis of the rock drilling tunnel.

[0011] In an optional implementation, after the upward fan-shaped deep hole blasting of each of the slotting areas is completed, an initial slot cavity is formed. In the direction along the mining area, the distance between the two cavity walls of the initial slot cavity is greater than the width of the cutting cross passage.

[0012] In an optional implementation, each of the upward parallel medium-deep holes in the two sets of expansion zones uses the sidewalls of the initial slot cavity formed by the slotting zone as the free surface for micro-differential blasting, and expands along the cutting transverse direction from the initial slot cavity to the sidewalls of the stope to form a cutting slot. In the direction perpendicular to the stope, the distance between the sidewalls of the cutting slot is equal to the width of the stope.

[0013] In an optional implementation, the coefficient of fragmentation is 1.3 to 1.6.

[0014] Compared to existing technologies, the beneficial effects of this application are: This application utilizes a single-stage blasting method with medium-deep holes to form a cutting groove. Upward-facing fan-shaped medium-deep holes and upward-facing parallel medium-deep holes are arranged in the cutting and widening zones, respectively. Using the bottom cutting cross passage as the initial free surface and compensation space, all blast holes in the entire cutting groove area undergo zoned micro-delay blasting. This achieves single-stage blasting of the cutting groove, avoiding the drawbacks of multiple charging operations near the edge of the formed goaf in multi-stage blasting processes, thus effectively improving the overall safety level of mining operations. Simultaneously, because single-stage blasting reduces multiple disturbances to the surrounding rock, it helps maintain the integrity and self-stabilizing capacity of the surrounding rock around the cutting groove, creating favorable conditions for subsequent mining operations. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart of a method for creating trenches in medium-deep holes by single-stage blasting is shown. Figure 2 A schematic diagram of the mining area distribution is shown; Figure 3 A schematic diagram of the borehole arrangement of the cutting groove is shown; Figure 4 It shows Figure 3 Schematic diagram of the AA section; Figure 5 It shows Figure 4 A schematic diagram of the cut-out area after the completion of the upward fan-shaped medium-deep hole blasting in the first four layers of the middle section; Figure 6 It shows Figure 5 A schematic diagram of the cut-out area after all upward fan-shaped deep-hole blasting has been completed; Figure 7 It shows Figure 3 Schematic diagram of the BB cross section; Figure 8 It shows Figure 7 A schematic diagram of the trench expansion zone after all upward parallel medium-deep holes have been blasted; Figure 9 It shows Figure 3 Schematic diagram of the CC section; Figure 10 A schematic diagram of the arrangement of boreholes in a row of upward fan-shaped medium-deep holes is shown; Figure 11 A schematic diagram of the arrangement of borehole #1 with multiple rows of upward fan-shaped deep holes is shown; Figure 12A schematic diagram of a row of upward parallel medium-deep boreholes is shown.

[0017] Explanation of key component symbols: 100 - Drilling tunnel; 200 - Cutting cross tunnel; 300 - Cutting groove; 400 - Mining area; 410 - Slotting area; 411 - Inclined hole; 420 - Enlarged slotting area; 421 - Vertical hole; 430 - Ore body. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0021] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0023] Please see Figure 2 This embodiment is applicable to mining operations, with three parallel mining areas 400. The middle mining area 400 is used as an example to illustrate blasting in this embodiment.

[0024] Please base on Figure 1 and Figure 2 Referring to the following figures, this embodiment provides a method for creating trenches in medium-deep holes using a single blasting operation. The method includes the following steps: Please see Figure 3 .

[0025] S100. Based on the design scheme of the 400 mining and cutting project, determine the layout and structural parameters of the drilling tunnel 100, the cutting cross tunnel 200, and the cutting groove 300.

[0026] The design includes the layout and structural parameters of the rock drilling tunnel 100, the layout and structural parameters of the cutting cross tunnel 200, and the layout and structural parameters of the cutting groove 300.

[0027] The dimensions of the cutting cross passage 200 are determined based on the equipment dimensions. Generally speaking, the dimensions of the cutting cross passage 200 are basically the same in different mining areas 400, based on the premise that the equipment can operate normally in the cutting cross passage 200.

[0028] The aforementioned equipment includes, but is not limited to, scrapers, rock drilling rigs, etc.

[0029] The cutting groove 300 is generally located at the end or middle of the stope 400. In this embodiment, the cutting groove 300 is arranged at the end of the stope 400 as an example.

[0030] S200. Determine the crushing expansion coefficient based on the type of ore and the size of the crushed ore blocks, and estimate the required compensation space. If the required compensation space is less than the space of the cutting cross passage 200, proceed to the next step.

[0031] The rock fragmentation coefficient is the ratio of the loose volume of the rock after it is broken to the original volume of the rock, reflecting the characteristic of the rock increasing in volume after it is broken.

[0032] The coefficient of fragmentation is an important parameter describing the volume change of rock after fracturing, commonly used in mining, tunnel engineering, and other fields. It represents the ratio of the volume of the rock after blasting, excavation, or other processes to the volume of the original rock. Generally, the coefficient of fragmentation is greater than 1 because the increased void space between particles after fracturing leads to an increase in the overall volume.

[0033] The coefficient of fragmentation is affected by a variety of factors, including: Rock type: The coefficient of fragmentation varies significantly among different lithologies (such as mudstone, sandstone, etc.), and is usually related to factors such as rock hardness, degree of fracture development, and size of fragmented blocks.

[0034] Particle size distribution: The uniformity of the size of the crushed particles affects the crushing expansion coefficient. The more uneven the particle size, the stronger the void filling ability and the lower the crushing expansion coefficient.

[0035] External pressure: If the crushed rock is compressed (such as by backfilling or self-weight compaction), the voids will decrease and the volume will shrink accordingly. In this case, the "compacted expansion coefficient" needs to be considered, which is usually less than the initial expansion coefficient.

[0036] In mining operations, the coefficient of fragmentation is of great significance for roof management and the study of mining subsidence patterns. By calculating the coefficient of fragmentation, better design and planning of mine backfill volume, transportation volume, and other parameters can be achieved.

[0037] The fragmentation coefficient is an important parameter in rock mechanics, and understanding its characteristics and influencing factors is of great guiding significance for engineering design and construction. In practical engineering, it is recommended to conduct detailed rock mechanics tests to determine the accurate fragmentation coefficient value.

[0038] Generally, the coefficient of fragmentation is 1.3 to 1.6, which needs to be determined based on factors such as lithology and fragment size.

[0039] When the required compensation space is less than the space of the cutting transverse tunnel 200, it indicates that the conditions for single-stage blasting trenching are met. The volume of ore to be blasted + the volume of the cutting transverse tunnel 200 > the volume of ore to be blasted. The coefficient of fragmentation can be determined by forming a cutting groove of 300 using a single blasting method.

[0040] S300. At the bottom of the stope 400, the rock drilling roadway 100 is constructed along the stope direction to the boundary of the stope 400. According to the cutting project layout plan, the rock drilling roadway 100 is excavated from both sides of the stope to the side wall boundary to form the cutting cross roadway 200. The cutting cross roadway 200 serves as the working site for the rock drilling and charging of the cutting slot 300 blast holes and the compensation space for blasting and falling ore.

[0041] In some embodiments, the end of the drilling tunnel 100 needs to extend 0.3m-0.5m beyond the design boundary of the mining area 400 to provide sufficient space for subsequent drilling operations and precise positioning.

[0042] Please see Figure 3 , Figure 4 and Figure 7 .

[0043] S400. The top of the cutting cross passage 200 is divided into a slotting area 410 and a widening area 420. Upward fan-shaped medium-deep holes are arranged in the slotting area 410, and upward parallel medium-deep holes are arranged in the widening area 420.

[0044] The cutting cross passage 200 is located below the cutting slot 300. The cutting cross passage 200 has a dual function: on the one hand, it serves as the work site for drilling and loading explosives; on the other hand, it provides a free surface and compensation space for the subsequent blasting of the cutting slot 300.

[0045] There are two sets of expansion zones 420, which are arranged on both sides of the cut zone 410. The cut zone 410 is arranged on the central axis of the rock drilling tunnel 100.

[0046] Using rock drilling equipment, with the roof of the 200-meter-wide transverse tunnel as the drilling working face, boreholes are drilled into the ore body at the designed angle and depth, including the following steps: The slotted area 410 is arranged with multiple rows of upward fan-shaped medium-deep holes, each row of which is formed by multiple inclined holes 411 arranged in a fan shape. The inclined holes 411 of the same angle in different rows are divided into one layer.

[0047] For ease of narration and understanding, such as Figure 3 , Figure 10 and Figure 11 As shown, three rows of upward fan-shaped medium-deep holes are arranged in the slotted area 410, numbered as row 1, row 2 and row 3 respectively. Each row of upward fan-shaped medium-deep holes includes seven inclined holes 411, numbered as 1#, 2#, 3#, 4#, 5#, 6# and 7# respectively.

[0048] To clearly illustrate the arrangement of the deep holes in each row of upward-facing fan-shaped sections, Figure 10 Only the arrangement of boreholes in one row is shown. Similarly, to clearly show the arrangement of boreholes on the same level, Figure 11 Only the arrangement of all No. 1 blast holes in different rows is shown, with the three No. 1 blast holes arranged at the same inclination angle.

[0049] For example, all #1 blast holes are defined as the first layer of blast holes. Similarly, the deep holes in the upward fan shape are divided into seven layers.

[0050] like Figure 3 and Figure 12 As shown, the expansion groove area 420 is arranged with multiple rows of upward parallel medium-deep holes, which are formed by multiple vertical holes 421 arranged in parallel.

[0051] For ease of description and understanding, and in accordance with the numbering conventions of those skilled in the art, six rows of upward parallel medium-deep holes are arranged in the two expansion zones 420. To distinguish them from the numbering of the slotting zone 410, the numbering of the slotting zone 410 is continued. The three rows of upward parallel medium-deep holes in the right expansion zone 420 are numbered as row 4, row 6 and row 8, respectively, and the three rows of upward parallel medium-deep holes in the left expansion zone 420 are numbered as row 5, row 7 and row 9, respectively.

[0052] To clearly illustrate the arrangement of the upward parallel medium-deep holes, Figure 12 Only the arrangement of 6 rows of blast holes is shown.

[0053] S500. In the cutting transverse lane 200, charge the upward fan-shaped medium-deep holes and the upward parallel medium-deep holes in one go.

[0054] Before loading explosives, all boreholes should be inspected and approved before centralized loading can proceed.

[0055] S600. After the charge is completed, all boreholes in the entire cutting groove area are subjected to zonal micro-delay blasting. First, the upper fan-shaped medium-deep holes of the slotting area 410 are blasted from bottom to top with the bottom cutting cross passage 200 as the free surface and compensation space. Then, the upper parallel medium-deep holes of the expansion area 420 are blasted with the slotting area 410 and the bottom cutting cross passage 200 as the free surface and compensation space.

[0056] The blasting sections are divided as follows: the inclined holes 411 located on the same layer are considered as one blasting section; each vertical hole 421 in each row is considered as one blasting section.

[0057] Please refer to the following: Figures 4 to 6 Using the bottom cutting cross passage 200 as the free surface and compensation space, the initial slot cavity is formed after the upward fan-shaped deep holes in the cut area 410 are blasted layer by layer, eliminating the need for empty hole construction and effectively improving construction efficiency. Furthermore, the layer-by-layer blasting method provides a larger effective free surface for subsequent blasting after each layer of upward fan-shaped deep hole blasting, thus significantly reducing the clamping effect of the surrounding rock on the blasting and improving the rock-breaking effect.

[0058] Please see Figure 7 and Figure 8 The two sets of expansion zones 420 each have upward parallel medium-deep holes with the sidewalls of the initial slot cavity formed by the slotting zone as the free surface, and micro-differential blasting is carried out. The cutting slots 300 are extended from the initial slot cavity to the sidewalls of the mining area 400 along the cutting cross roadway 200. The above construction method achieves precise control of the boundary of the cutting slots 300 and ensures that the outline is regular after blasting.

[0059] Please see Figure 9In the direction along the stope, the distance between the two walls of the initial slot is greater than the width of the cutting cross passage 200. After blasting, in the direction perpendicular to the stope, the distance between the two sides of the cutting slot 300 is equal to the width of the stope 400.

[0060] Please refer to the following: Figure 4 and Figure 7 In this embodiment, the cutting groove 300 is formed by combining upward fan-shaped medium-deep holes and upward parallel medium-deep holes. The blasting operation is carried out in the order of first removing the groove area 410 and then expanding the groove area 420. The upward fan-shaped medium-deep holes in the groove area 410 are blasted by inter-layer micro-delay blasting, and the upward parallel medium-deep holes in the expanding groove area 420 are blasted by inter-row micro-delay blasting.

[0061] Please refer to further information. Figures 4 to 6 For example, each row of upward fan-shaped deep holes consists of seven inclined holes 411. The seven inclined holes 411 are divided into seven layers, numbered starting from the layer closest to the bottom. The first layer of blast holes (i.e., blast hole 1) is blasted first. After the first layer of blast holes is blasted, a new free surface and compensation space are formed. When the second layer of blast holes is blasted, the rubble from the second layer of blast holes can fall into the compensation space. After blasting layer by layer, new compensation spaces are continuously formed to meet the subsequent ore falling needs.

[0062] Specifically, the inclined holes 411 in each row are detonated layer by layer in a bottom-up sequence, so that the free surface of the explosion expands upward.

[0063] Each inclined hole 411 in each row is a blasting segment, and each segment corresponds to a delay time. It can also be understood that the segments that detonate at the same time point are a segment. For example, 1# in row 1, 1# in row 2, and 1# in row 3 are the first segment, 2# in row 1, 2# in row 2, and 2# in row 3 are the second segment, and so on, 1# in row 4, 2# in row 4, 3# in row 4, and 4# in row 4 are the eighth segment.

[0064] During the blasting, the blasting is carried out sequentially, starting with the first layer of blast holes, then the second layer, third layer, and so on, at predetermined intervals, until the seventh layer of blast holes is completely blasted. Figure 4 As shown, none of the upward-facing fan-shaped deep holes have begun to blast, as... Figure 5 As shown, the blasting proceeded to the fourth layer of blast holes, as... Figure 6 As shown, the blasting continued until the seventh layer of blast holes, meaning all the upward-facing fan-shaped medium-deep holes were blasted.

[0065] like Figure 3 As shown, after the blasting of the slotted area 410 is completed, the blasting of the expansion area 420 is carried out.

[0066] Please refer to further information. Figure 7 and Figure 8Each row has four vertical holes 421 arranged in it, and these four vertical holes 421 form a blasting section.

[0067] The parallel medium-deep holes in the two-sided expansion zones have the following three blasting methods: First, blast all the blast holes in one side of the trench expansion area row by row, then blast all the blast holes in the other side of the trench expansion area row by row. For example, blast the 4th row first, then the 6th row, then the 8th row, then the 5th row, then the 7th row, and finally the 9th row.

[0068] Alternatively, the blast holes in the expansion slots on both sides can be blasted alternately. For example, blast the 4th row first, then the 5th row, then the 6th row, then the 7th row, then the 8th row, and finally the 9th row.

[0069] You can also simultaneously blast the blast holes near the initial slot cavity in both sides of the expansion zone, for example, blast all the blast holes in rows 4 and 5 at the same time, and then blast rows 6 and 7, and so on.

[0070] Of course, in some other embodiments, please refer to the relevant literature. Figure 4 and Figure 7 The number of inclined holes 411 and vertical holes 421 in each row can be other numbers, and the number of layers can be adaptively changed according to the space of the cutting cross alley 200.

[0071] The arrangement of deep holes in an upward fan shape utilizes the ore's own weight to fall, which can significantly improve the utilization rate of blasting energy. The blasting process is progressive, with each row of blasts creating a larger free surface for subsequent blasts, fully releasing the rock clamping force, thereby efficiently crushing and throwing out the rock and ore within a limited compensation space, and quickly forming the initial cavity.

[0072] The arrangement of blast holes in the cut zone 410 needs to extend appropriately beyond the boundary of the cutting groove 300 to provide a larger free surface for subsequent blasting in the expansion zone 420. Upward parallel medium-deep holes are arranged within the expansion zone 420. This upward parallel hole arrangement facilitates control of the blasting profile, precisely expanding the groove cavity to the designed boundary of the cutting groove 300, effectively controlling over-excavation or under-excavation.

[0073] It should be noted that the number, diameter, spacing, depth, dip angle, and minimum resistance line of the boreholes in the slotting zone 410 and the widening zone 420 should be designed and dynamically optimized based on the firmness coefficient of the rock and ore, the degree of joint development, and the characteristics of the explosives.

[0074] The blasting of the entire cutting groove 300 adopted a zoned micro-delay blasting scheme of "first excavating the groove, then expanding the groove" and "progressing layer by layer from bottom to top".

[0075] Using the bottom cutting cross passage 200 as the initial free surface and compensation space, the micro-delay detonation technology is adopted to detonate the top of the cutting groove 300 layer by layer in a bottom-up order, thereby forming a narrow and elongated groove cavity that runs vertically through the middle of the cutting groove 300, creating a new free surface and compensation space for the subsequent blasting of the expansion zone 420.

[0076] The 410-layer blasting in the slotted area can utilize the compensation space created by the blasting below to gradually expand the blasting compensation space.

[0077] Utilizing the compensation space formed by the cut-out area 410 and the bottom cutting cross passage 200, the blast holes in the expansion area 420 are detonated with a micro-delay time, gradually expanding from the side near the cut-out area 410 towards the boundary of the stope 400, forming a regular and complete cutting groove 300.

[0078] This embodiment achieves efficient one-time forming of the cutting groove 300 by implementing a single centralized charge in all blast holes and using zoned micro-delay blasting technology to control the blasting sequence. This solution not only simplifies the work process and avoids work interruptions caused by multiple blasts, improving construction efficiency, but also significantly reduces the frequency of worker exposure near the goaf, thus enhancing intrinsic safety.

[0079] Furthermore, in this embodiment, the throwing direction of the blasted ore is consistent with the direction of gravity-induced ore falling, effectively utilizing gravitational potential energy to assist in ore falling, and significantly improving the effective conversion rate of blasting energy and the quality of ore crushing.

[0080] Please see Figure 3 In this embodiment, the layout and structural dimensions of the drilling tunnel 100, the cutting cross tunnel 200, and the cutting groove 300 are pre-designed. Then, based on the type of ore and the size of the crushed ore pieces, the fragmentation coefficient is determined, and the required compensation space is estimated. If the required compensation space is less than the space of the cutting cross tunnel 200, blast holes are arranged in the slotting area 410 and the widening area 420 respectively. This enables the cutting groove 300 to be formed by blasting in one go, without the need to repeatedly enter the site to load explosives, thereby improving the mining safety factor and ensuring the overall stability of the surrounding rock.

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for creating trenches in medium-deep holes using a single blasting operation, characterized in that, include: Based on the mining and cutting engineering design plan, determine the layout and structural parameters of the drilling tunnels, cutting cross tunnels, and cutting slots; Based on the type of ore and the size of the crushed ore, determine the crushing expansion coefficient and estimate the required compensation space. If the required compensation space is less than the space for cutting the transverse tunnel, proceed to the next step. At the bottom of the mining area, the rock drilling tunnel is constructed along the mining area direction to the mining area boundary. According to the cutting project layout plan, the rock drilling tunnel is excavated from the rock drilling tunnel to both sides of the mining area to the side wall boundary to form a cutting cross tunnel. The cutting cross tunnel serves as the working site for rock drilling and charging of cutting slot blast holes and the compensation space for blasting and falling ore. The top of the cutting cross passage is divided into a slotting area and a widening area. Upward fan-shaped medium-deep holes are arranged in the slotting area, and upward parallel medium-deep holes are arranged in the widening area. The upward fan-shaped medium-deep hole and the upward parallel medium-deep hole are loaded with explosives in a single operation within the cutting transverse tunnel; After the explosive charge is completed, all boreholes in the entire cutting groove area are subjected to zonal micro-delay blasting. First, the upward fan-shaped medium-deep holes are blasted layer by layer from bottom to top, with the bottom cutting cross passage as the free surface and compensation space. Then, the upward parallel medium-deep holes are blasted with the slotting area and the bottom cutting cross passage as the free surface and compensation space.

2. The method for creating trenches in medium-deep holes by single-pass blasting as described in claim 1, characterized in that, The slotted area is arranged with multiple rows of upward fan-shaped deep holes. Each row of upward fan-shaped deep holes is composed of multiple inclined holes arranged in a fan shape, and the inclined holes of different rows with the same angle are divided into a layer.

3. The method for creating trenches in medium-deep holes by single-stage blasting as described in claim 2, characterized in that, Each inclined hole within the same layer is considered as a blasting section.

4. The method for forming trenches in medium-deep holes by one-time blasting as described in claim 3, characterized in that, The upward-sloping fan-shaped deep holes are detonated layer by layer from bottom to top, allowing the blast free surface to expand upward.

5. The method for creating a trench in a medium-deep hole using a single blasting operation as described in any one of claims 1 to 4, characterized in that, The expansion groove area is arranged with multiple rows of upward parallel medium-deep holes, and each row of upward parallel medium-deep holes is composed of multiple vertical holes arranged in parallel.

6. The method for creating trenches in medium-deep holes by single-pass blasting as described in claim 5, characterized in that, Each vertical hole in each row constitutes a blasting section.

7. The method for forming trenches in medium-deep holes by single-stage blasting as described in any one of claims 1 to 4, characterized in that, The number of expansion zones is two sets, which are arranged on both sides of the slotting zone, and the slotting zone is arranged on the central axis of the rock drilling tunnel.

8. The method for creating trenches in medium-deep holes by single-pass blasting as described in claim 7, characterized in that, After the upward fan-shaped deep hole blasting in the slotting area is completed, an initial slot cavity is formed. In the direction along the mining area, the distance between the two cavity walls of the initial slot cavity is greater than the width of the cutting cross passage.

9. The method for creating trenches in medium-deep holes by single-pass blasting as described in claim 8, characterized in that, Each of the two sets of upward parallel medium-deep holes in the expansion zone uses the sidewalls of the initial slot cavity formed by the slotting zone as the free surface for micro-differential blasting. The cutting slots are extended from the initial slot cavity to the sidewalls of the stope along the direction of the cutting transverse roadway to form cutting slots. In the direction perpendicular to the stope direction, the distance between the sidewalls of the cutting slots is equal to the width of the stope.

10. The method for forming a trench in a medium-deep hole by one-time blasting as described in any one of claims 1 to 4, characterized in that, The coefficient of fragmentation is 1.3~1.6.

Images