A four-side filling in-situ roof column upward medium-deep hole mining method

Abstract

The present application relates to the technical field of mining, in particular to a kind of four filling body in top pillar upward medium-length hole mining method, comprising the following steps: preparation, the selection and excavation of slot area, the blast hole position in slot area is arranged, the blast hole position in the drilling roadway is arranged, construction upward blast hole position, upward blast hole position charges, plugging and blasting preparation and blasting etc., the present mining method is through the arrangement of top pillar stope structure, slot area charging hole and positive row fan-shaped blast hole, solve the problem of high risk coefficient and large mining capacity in the process of four filling body top pillar recovery;Also solve the problem of a large amount of ore powder produced in the blasting process;Slot area is provided with charging hole and compensation empty hole, which is convenient for cutting well and material falling after blasting in later blasting construction. By cutting well along the length direction of top pillar, segment delay blasting is carried out, which is beneficial to slag removal and provides sufficient compensation space for post-response blast hole, reduces the generation of blind blasting.

Description

Technical Field

[0001] This invention relates to the field of mining technology, specifically to a method for mining medium-deep holes from the top pillar of a four-sided filled body. Background Technology

[0002] In underground mining, many mines choose the pillar mining method, which is characterized by high safety risks and difficulty in production recovery. Currently, conventional pillar mining mines generally adopt the upward medium-deep hole followed by backfilling mining method with segmented retreat mining. The width of the segmented section is generally about 5m. YGZ-90 drills are used to drill upward fan-shaped medium-deep holes in the rock drilling roadway. Cutting slot blasting technology is used to create the shaft, and a remote-controlled loader is used to extract the ore. After extraction, backfilling is carried out.

[0003] Because pillar mining involves segmented, intermittent mining, with each segment being mined separately, after backfilling, only strip-shaped pillars remain, surrounded by backfill on all four sides. This fundamentally changes the mining conditions for this section of the pillar, making mining significantly more difficult. The original mining parameters are no longer suitable for this type of pillar mining. Furthermore, the original pillar mining process suffers from low production capacity per stope, dense blast holes, low ore yield per unit length of blast hole, high explosive consumption, high fines ratio, and excessively small ore blocks. This is particularly problematic in mines with complex hydrological conditions, leading to difficulties in fines recovery. Additionally, pillar stops are typically adjacent to backfill; inadequate roof support and sidewall control can cause backfill to collapse and mix into the ore heap water, easily causing the ore heap to become sticky and prone to compaction, negatively impacting subsequent ore transportation and hoisting. Summary of the Invention

[0004] In order to overcome one of the shortcomings of the prior art, the purpose of this invention is to provide a method for mining medium-deep holes with a top pillar inside a four-sided filled body. This method reduces the safety difficulty and mining cost of mining operations and improves the production capacity of the stope.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for mining medium-deep holes with a top pillar inside a four-sided filled body includes the following steps:

[0007] Preparation: During the mining of the stope, increase the width of the reserved pillar stope to 6-7m. Before mining the pillar stope, complete the filling of the four sides of the pillar stope. Along the direction of the pillar stope, drill through the rock tunnel at the bottom to ensure that the thickness of the support pillars on both sides of the rock tunnel is at least 2-3m.

[0008] Selection and excavation of the trenching zone: Select an area with relatively stable roof rock in the pillared stope to expand and lift the roof, and obtain the trenching zone;

[0009] Arrange the blasting holes in the slotted area: Select a central blasting point in the slotted area, drill a charging hole at the central blasting point, and drill several compensation holes at equal intervals around the central blasting point. All compensation holes are arranged in a grid pattern. Drill at least 4 compensation holes and at least 4 charging holes at equal intervals outside all the compensation holes. All the above-mentioned charging holes and compensation holes are spaced apart. All the compensation holes and charging holes together form the cutting well area, and the cross-section of the cutting well area is square.

[0010] Arrange blasting holes in the rock drilling tunnel: Arrange several rows of fan-shaped holes every 1.8m-2m along the excavation direction in the controlled area of ​​the rock drilling tunnel. According to the width of the top pillar stop, the bottom distance of all the fan-shaped holes in the controlled area of ​​the rock drilling tunnel is evenly distributed. Arrange several side control blasting holes on both sides of each row of fan-shaped holes in the rock drilling tunnel.

[0011] Construction of upward blasting holes: In the slotted area, construction proceeds from bottom to top, drilling compensation holes and charging holes at preset depths. Select any one compensation hole and construct it as a test hole. The test hole penetrates the entire top pillar stope. The construction depth of the remaining charging holes is 0.5m lower than the depth of the test hole. In all the positive row fan-shaped holes, select one row every three rows to construct as a test hole. The depth of the other positive row fan-shaped holes is 0.5m lower than the depth of the test hole.

[0012] Upward blasting hole loading and plugging: Use foam material to fill the bottom of the positive row of fan-shaped holes and the loading hole, with a filling height of 0.5-0.6m, and set the filling height of 1.5-2m for the opening of the positive row of fan-shaped holes;

[0013] Blasting preparation and blasting: Set the blasting delay parameters for the stope. In the slotted area, detonation proceeds sequentially from the central blasting point outwards. The main row of fan-shaped holes and the control blasting holes are blasted sequentially from one end of the slotted area toward the direction of the drilling tunnel. The main row of fan-shaped holes and the control blasting holes are detonated using a delayed detonation method with the same charge in the same row and section. The blasting is controlled by digital electronic detonators. After blasting, the ore is removed by a remote-controlled loader.

[0014] Furthermore, in the steps of selecting and excavating the trenching area, the width of the trenching area is less than or equal to the width of the top column.

[0015] Furthermore, the step of arranging the blasting holes in the slotted area also includes drilling several peripheral blasting holes outside the cutting well area until all peripheral blasting holes are evenly distributed throughout the slotted area, and the arrangement points of the peripheral blasting holes and the charging holes together form the same grid.

[0016] Furthermore, the mesh size of the grid formed by all the charging holes and the surrounding blast holes is 1×1m.

[0017] Furthermore, the step of arranging the blasting holes within the grooved area includes the following steps:

[0018] Select a central blasting point in the slotted area, drill a charge hole at the central blasting point, and drill four outer ring compensation holes at equal intervals with the central blasting point as the center. The four compensation holes are arranged in a grid pattern.

[0019] Four points are set up on the outer side of the four compensation holes at an equal scale. The scale is inversely proportional to the strength of the roof rock in the top pillar stope. Charge holes are drilled and formed at these four points. The diameter of the charge holes is 50-80mm. A compensation hole is drilled at the midpoint between the two nearest adjacent charge holes. The diameter of the compensation hole is 60-80mm. The area enclosed by the charge holes and compensation holes in this circle together constitutes the cutting well area.

[0020] Furthermore, at least one ring of compensation holes was drilled on the outer ring of the aforementioned cutting well area.

[0021] Furthermore, in the step of arranging the blasting holes in the rock drilling tunnel, there are three sets of control blast holes, which penetrate the side wall of the entire support column and are connected to the filling material.

[0022] Furthermore, in the preparatory work steps, a reinforced filling layer is set at the bottom of the filling body located at the top of the top pillar stope, and several ground grids are set in the reinforced filling layer; the strength of the reinforced filling layer must be greater than the strength of the filling body at the bottom of the top pillar stope, and the ratio between the thickness of the reinforced filling layer and the height of the top pillar stope is 1:2-3.

[0023] Furthermore, in the steps of blasting preparation and blasting: when the main row of fan-shaped holes and control blast holes are blasted in a backward manner from one end of the slotting area towards the direction of the rock drilling tunnel, the blasting interval between adjacent rows of main row fan-shaped holes and control blast holes gradually increases.

[0024] Furthermore, in the steps of loading and plugging the blasting holes from the top, the foam material filling the bottom of the fan-shaped holes of the exploratory filling holes should leave a protective space of at least 50cm from the bottom opening of the exploratory filling holes.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] This invention discloses a method for mining medium-deep holes from the top pillar within a four-sided infill stope. By optimizing the top pillar stope structure, the arrangement of charging holes in the slotted area, the fan-shaped blast holes, and the corresponding blasting scheme, this method addresses the high risk and high mining energy issues during the mining of the top pillar in a four-sided infill stope. It also solves the problem of generating large amounts of ore powder during blasting. Furthermore, the placement of charging holes and compensation holes in the slotted area facilitates the creation of cutting shafts during subsequent blasting operations and addresses the issue of material discharge after blasting, thus improving construction safety. Moreover, the method involves segmented delayed blasting along the length of the top pillar from the cutting shaft, and segmented caving of the top pillar stope, which facilitates slag removal and provides sufficient compensation space for subsequent blast holes, reducing the occurrence of misfires.

[0027] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0028] Figure 1 This is a plan view of an embodiment of the present invention;

[0029] Figure 2 This is an elevation view along the length of the top pillar stope in an embodiment of the present invention;

[0030] Figure 3 This is a diagram showing the arrangement of blast holes in the grooved area according to an embodiment of the present invention.

[0031] Figure 4 yes Figure 1 Elevation view along direction AA;

[0032] Figure 5 yes Figure 1 Elevation view along the BB direction. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] See Figures 1 to 5 This application provides a method for mining medium-deep holes from the top pillar within a four-sided filled body, comprising the following steps:

[0035] S100. Preparatory work: During the mining of stope 1, the width of the reserved top pillar stope 2 will be increased to 6-7m. Before the mining of top pillar stope 2, the four sides of top pillar stope 2 will be filled with filling body 3. Along the direction of top pillar stope 2, the bottom of the rock drilling tunnel 4 will be drilled through to ensure that the thickness of the support pillars 5 on both sides of the rock drilling tunnel 4 is at least 2-3m.

[0036] S200, Selection and excavation of the trenching zone: Select an area with relatively stable roof rock in the top pillar stope 2 to expand and scour the roof, and obtain the trenching zone 6;

[0037] S300. Arrange the blasting holes in the slotted area: Select a central blasting point in the slotted area 6, drill a charging hole 7 at the central blasting point, and drill several compensation holes 8 at equal intervals around the central blasting point. All compensation holes 8 are arranged in a grid pattern. Drill at least 4 compensation holes 8 and at least 4 charging holes 7 at equal intervals outside all compensation holes 8. All the above-mentioned charging holes 7 and all compensation holes 8 are arranged at intervals. All compensation holes 8 and charging holes 7 together form the cutting well area 9, and the cross-section of the cutting well area 9 is square.

[0038] S400. Arrange blasting holes in the rock drilling tunnel: In the control area of ​​rock drilling tunnel 4, arrange several rows of fan-shaped holes 10 every 1.8m-2m along the excavation direction. According to the width of the top pillar stop 2, the bottom distance of all the fan-shaped holes 10 in the control area of ​​rock drilling tunnel 4 is evenly distributed. Arrange several side control blasting holes 11 on both sides of each row of fan-shaped holes 10 in rock drilling tunnel 4.

[0039] S500, Construction of upward blasting holes: In the slotted area 6, construction proceeds from bottom to top, drilling compensation holes 8 and charging holes 7 at preset depths. Select any compensation hole 8 and construct it as a test hole 12. The test hole 12 penetrates the entire top pillar stope 2. The construction depth of the remaining charging holes 7 is reduced by 0.5m relative to the depth of the test hole 12. In all the positive rows of fan-shaped holes 10, select one row every three rows to construct as a test hole 12. The depth of the other positive rows of fan-shaped holes 10 is reduced by 0.5m compared to the depth of the test hole 12.

[0040] S600, Upward blasting hole loading and plugging: Use foam material to fill the bottom of the positive row fan-shaped holes 10 and the loading hole 7, with a filling height of 0.5-0.6m, and set the filling height of 1.5-2m for the opening of the positive row fan-shaped holes 10.

[0041] S700, Blasting Preparation and Blasting: Set the blasting delay parameters for the stope. In the slotting area 6, the blasting is initiated sequentially from the central blasting point outwards. The fan-shaped holes 10 and the control holes 11 are blasted sequentially from one end of the slotting area 6 toward the direction of the drilling tunnel 4. The fan-shaped holes 10 and the control holes 11 are detonated using a delayed initiation method with the same charge in the same row and section. The blasting is controlled by digital electronic detonators. After the blasting, the ore is removed by a remote-controlled shovel.

[0042] It should be noted that in step S700, the main row of fan-shaped holes 10 and the control-edge blast holes 11 are detonated using a delayed detonation method with charges in the same row and section. Simply put, each row of main row fan-shaped holes 10 and control-edge blast holes 11 is detonated simultaneously, which improves ore blasting efficiency and reduces ore powder generation. It should also be noted that the orientation of each row of fan-shaped holes 10 and control-edge blast holes 11 on the top pillar stope 2 can be understood as being arranged along the cross-sectional direction of the top pillar stope 2. For ease of explanation, the term "blast hole" will be used below to describe the main row of fan-shaped holes 10, the charge holes 8, and the control-edge blast holes 11.

[0043] In step S500, the bottom distance of the blast holes in the top pillar stope is evenly distributed, and the bottom distance of the hole is 0.5m from the filling body as the top layer. The construction depth of the charging hole 7 is 0.5m lower than the depth of the exploratory filling hole 12, which can be used as the side layer.

[0044] This method of mining deep-hole blasting from the top pillar within a four-sided infill body solves the problems of high risk and high mining energy during the mining of the top pillar in the four-sided infill body 3 by arranging the structure of the top pillar stope 2, the charging holes 7 in the slotted area 6, and the fan-shaped blast holes, as well as the corresponding blasting scheme. It also solves the problem of generating a large amount of ore powder during blasting. Furthermore, the placement of the charging holes 7 and compensation holes 8 in the slotted area 6 facilitates the later blasting construction of the cutting shaft 9 and addresses the issue of material discharge after blasting, thus improving construction safety. Moreover, the segmented delayed blasting along the length of the top pillar from the cutting shaft 9, and the segmented caving of the top pillar stope 2, facilitates slag removal and provides sufficient compensation space for subsequent blast holes, reducing the occurrence of misfires.

[0045] See Figures 1 to 3 In step S100, since the four sides of the top pillar stope 2 are filled with body 3, and the front and rear ends of the top pillar stope 2 are also connected to the cross-vein roadway, the body 3 is relatively easy to collapse in the actual production process. Therefore, in the early stage of mining the stope 1, the width of the reserved top pillar stope 2 is increased to 6-7m. The main purpose is to ensure a stable structure and safety when excavating the rock drilling roadway 4 in the later stage. At the same time, the body 3 on the four sides are far apart from each other, forming a stable backfill structure, which also facilitates the backfilling of the top pillar stope 2 in the later stage.

[0046] In step S100, to prevent the collapse of the fill material 3 at the top of the top pillar stope 2 after blasting, in one embodiment of this application, a reinforced fill layer 14 is provided at the bottom of the fill material 3 at the top of the top pillar stope 2, and several ground grids 15 are provided within the reinforced fill layer 14. The strength of the reinforced fill layer 14 needs to be greater than the strength of the fill material 3 at the bottom of the top pillar stope 2, and the ratio between the thickness of the reinforced fill layer 14 and the height of the top pillar stope 2 is 1:2-3. The reinforced fill layer 14 is formed during the backfilling of the fill material 3, and its main purpose is to improve the strength of this area, preventing the stope 2 from collapsing due to loss of support during mining. Simultaneously, the strength of the fill material 3 in this area must be greater than that of the fill material 3 in other areas. For example, in one embodiment of this application, the strength of the reinforced fill layer 14 is 5 MPa, while the strength of the fill material 3 at the bottom of the top pillar stope 2 only needs to be 1 MPa, and the strength of the fill material 3 on both sides only needs to be 3 MPa, thus reducing backfilling costs. In the aforementioned structure, the preferred ratio between the thickness of the reinforced filling layer 14 and the height of the top pillar stope 2 is 1:2.5. The ground grid 15 can be a steel cage structure or a steel fork structure, which can improve tensile strength and prevent the top of the top pillar stope 2 from collapsing after mining. In some embodiments, a portion of the top pillar stope 2 can be reserved, meaning that the entire stope 2 is not blasted during blasting; the reserved portion can be used as a roof, increasing the safety of the stope 2. Specifically, in this application, the construction depth of the charging hole 7 is 0.5m lower than the depth of the exploratory hole 12; the depth of the fan-shaped holes 10 is also 0.5m lower than the depth of the exploratory holes 12. This design also aims to reserve a roof and prevent the entire top pillar stope 2 from collapsing.

[0047] Furthermore, in one embodiment of this application, in step S200, the width of the slotted area 6 is less than or equal to the width of the top pillar; its main purpose is to facilitate expanding the mining range of the slotted area 6 as much as possible while ensuring safety, and also to ensure that the ore has sufficient space to fall and be discharged after blasting in other areas of the top pillar stope 2. Moreover, the slotted area 6 does not experience over-mining, avoiding the collapse of the surrounding fill material 3, thus improving the safety of mining.

[0048] In step S300, to achieve complete blasting of the slotted area 6 as much as possible, in one embodiment of this application, several peripheral blast holes 13 are drilled outside the area of ​​the cutting well 9 until all peripheral blast holes 13 are evenly distributed throughout the slotted area 6. The locations of the peripheral blast holes 13 and the charging holes 7 together form the same grid. The main purpose is to ensure that when blasting the slotted area 6 in the later stages, the blasting points are blasted sequentially according to the predetermined blasting points, avoiding situations where there is a sudden increase in local blasting size or relatively weak blasting points, which would lead to different blasting effects each time, thus improving the safety of the blasting.

[0049] In the above embodiment, since the slotting zone 6 is located at one end of the top pillar stope 3 and in order to better realize the blasting and material dropping, the mesh size of the grid formed by all the charging holes 7 and the surrounding blast holes 13 is 1×1m. If the mesh size is too large, the size of the ore produced by blasting will also be too large, which is not conducive to transportation and will also make the ore easy to get stuck and not easy to drop. Conversely, if the mesh size is too small, the size of the ore will be smaller, which is easy to drop, but will produce too much mineral powder, which is not conducive to later transportation and recycling.

[0050] In one embodiment of this application, step S300 specifically includes the following steps:

[0051] S310. Select a central blasting point in the slotted area 6, drill a charging hole 7 at the central blasting point, and drill four outer ring compensation holes 8 at equal intervals with the central blasting point as the center. The four compensation holes 8 are arranged in a grid pattern.

[0052] S320. Four points are set up on the outside of the four compensation holes 8 at an equal scale. The scale is inversely proportional to the strength of the roof rock of the top pillar stope 2. Charge holes 7 are drilled and formed at these four points. The diameter of the charge holes 7 is 50-80mm. A compensation hole 8 is drilled at the midpoint between the two nearest adjacent charge holes 7. The diameter of the compensation hole 8 is 60-80mm. The area enclosed by the charge holes 7 and the compensation holes 8 together constitute the cutting well 9 area.

[0053] In the above embodiment, the central detonation point is located in the middle area of ​​the grooved zone 6, which facilitates sequential outward detonation during detonation and ensures stability; moreover, it avoids the detonation point being too close to the filler 3, which could cause the filler 3 to collapse during detonation.

[0054] In the improved embodiment described above, at least one ring of compensation holes 8 is drilled on the outer ring of the cutting well 9 area. The main purpose of this is to absorb the impact force generated by the charge hole 7 during the explosion, and at the same time, to make the rock strata have certain weak points that are easy to break off during blasting, improve the regularity of blasting, and at the same time, to protect the safety of the filling material 3 around the top pillar stope 2.

[0055] Furthermore, in step S400, to ensure the blasting effect, three sets of control blast holes 11 are used. These control blast holes 11 penetrate the entire sidewall of the support column 5 and connect to the filling material 3. In practice, since both sides of the support columns 5 collapse into the drilling tunnel 4 during blasting, material discharge is effectively achieved, providing sufficient space for subsequent blasting. It should be noted that in the subsequent step S700, the control blast holes 11 and the corresponding front-row fan-shaped holes 10 on the same cross-section are detonated simultaneously.

[0056] In one embodiment, in step S600, the foam material filling the bottom of the positive row of fan-shaped holes 10 of the test hole 12 leaves a protective space of at least 50 cm between the bottom opening of the test hole 12 and the top. The main purpose of this protective space is to better protect the filler 3 and prevent the explosive charge from being too close to the filler 3, which could cause the filler 3 to collapse during subsequent blasting. Furthermore, it should be noted that in step S600, the bottom of the borehole is the upper end of the aforementioned charge hole 7 and positive row of fan-shaped holes 10, while the open end is the end from which the charge hole 7 and positive row of fan-shaped holes 10 are drilled, which in this application is the lower end.

[0057] Furthermore, in step S700, when the front row of fan-shaped holes 10 and the control edge blasting holes 11 are blasted sequentially from one end of the slotting area 6 toward the rock drilling tunnel 4 in a backward blasting manner, the blasting interval between adjacent rows of front row fan-shaped holes 10 and control edge blasting holes 11 gradually increases. The purpose of this is mainly to allow the area that is blasted first to have enough time for material to fall, so as to provide sufficient material falling space for the area to be blasted later and to achieve safe blasting.

[0058] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A method for mining medium-deep holes from a top pillar within a four-sided filled body, characterized in that, Includes the following steps: Preparation: During the mining of the stope, increase the width of the reserved pillar stope to 6-7m. Before mining the pillar stope, complete the filling of the four sides of the pillar stope. Along the direction of the pillar stope, drill through the rock tunnel at the bottom to ensure that the thickness of the support pillars on both sides of the rock tunnel is at least 2-3m. Selection and excavation of the trenching zone: Select an area with relatively stable roof rock in the top pillar stope to expand and excavate the roof, and obtain the trenching zone; the width of the trenching zone is less than or equal to the width of the top pillar; Arranging blasting hole positions within the slotted area: Select a central blasting point within the slotted area, drill a charge hole at the central blasting point, and drill several compensation holes at equal intervals around the central blasting point, all of which are arranged in a grid pattern; drill at least four compensation holes and at least four charge holes at equal intervals outside all the compensation holes; all the charge holes and compensation holes are spaced apart; all the compensation holes and charge holes together form a cutting well area, the cross-section of which is square; the steps for arranging blasting hole positions within the slotted area include the following: Select a central blasting point in the slotted area, drill a charge hole at the central blasting point, and drill four outer ring compensation holes at equal intervals with the central blasting point as the center. The four compensation holes are arranged in a grid pattern. Four points are set up on the outside of the four compensation holes at an equal scale. The scale is inversely proportional to the strength of the roof rock in the top pillar stope. Charge holes are drilled and formed at these four points. The diameter of the charge holes is 50-80mm. A compensation hole is drilled at the midpoint between the two nearest adjacent charge holes. The diameter of the compensation hole is 60-80mm. The area enclosed by the charge holes and compensation holes in this circle together constitutes the cutting well area. Arrange blasting holes in the rock drilling tunnel: Arrange several rows of fan-shaped holes every 1.8m-2m along the excavation direction in the controlled area of ​​the rock drilling tunnel. According to the width of the top pillar stop, the bottom distance of all the fan-shaped holes in the controlled area of ​​the rock drilling tunnel is evenly distributed. Arrange several side control blasting holes on both sides of each row of fan-shaped holes in the rock drilling tunnel. Construction of upward blasting holes: In the slotted area, construction proceeds from bottom to top, drilling compensation holes and charging holes at preset depths. Select any one compensation hole and construct it as a test hole. The test hole penetrates the entire top pillar stope. The construction depth of the remaining charging holes is 0.5m lower than the depth of the test hole. In all the positive row fan-shaped holes, select one row every three rows to construct as a test hole. The depth of the other positive row fan-shaped holes is 0.5m lower than the depth of the test hole. Upward blasting hole loading and plugging: Use foam material to fill the bottom of the loading hole and the positive row of fan-shaped holes, with a filling height of 0.5-0.6m, and the opening of the positive row of fan-shaped holes is filled with a filling height of 1.5-2m; Blasting preparation and blasting: Set the blasting delay parameters for the stope. In the slotted area, detonation proceeds sequentially from the central blasting point outwards. The main row of fan-shaped holes and control blast holes are blasted sequentially from one end of the slotted area toward the direction of the drilling tunnel. The main row of fan-shaped holes and control blast holes are detonated using a delayed detonation method with the same charge in the same row and section. Digital electronic detonators are used to control the blasting and ore excavation. After blasting, a remote-controlled shovel is used to remove the ore. When the main row of fan-shaped holes and control blast holes are blasted in a backward manner from one end of the slotted area toward the direction of the drilling tunnel, the blasting interval between adjacent rows of main row fan-shaped holes and control blast holes gradually increases.

2. The method for mining medium-deep holes from the top pillar within a four-sided filled body according to claim 1, characterized in that: The step of arranging blasting holes in the slotted area also includes drilling several peripheral blasting holes outside the cutting well area until all peripheral blasting holes are evenly distributed throughout the slotted area, and the arrangement points of peripheral blasting holes and charging holes together form the same grid.

3. The method for mining medium-deep holes from the top pillar within a four-sided filled body according to claim 2, characterized in that: The mesh size of the grid formed by all the charging holes and the surrounding blast holes is 1×1m.

4. The method for mining medium-deep holes from the top pillar within a four-sided filled body according to claim 1, characterized in that: At least one ring of compensation holes was drilled on the outer edge of the aforementioned cutting well area.

5. A method for mining medium-deep holes with a top pillar inside a four-sided filled body according to claim 1, characterized in that: In the step of arranging blasting holes in the rock drilling tunnel, there are three sets of control blasting holes. The control blasting holes penetrate the side wall of the entire support column and are connected to the filling material.

6. A method for mining medium-deep holes with a top pillar inside a four-sided filled body according to claim 1, characterized in that: In the preparatory work, a reinforced filling layer is set at the bottom of the filling body located at the top of the top pillar stope, and several ground grids are set in the reinforced filling layer; the strength of the reinforced filling layer must be greater than the strength of the filling body at the bottom of the top pillar stope, and the ratio between the thickness of the reinforced filling layer and the height of the top pillar stope is 1:2-3.

7. A method for mining medium-deep holes from the top pillar within a four-sided filled body according to claim 1, characterized in that: In the steps of loading and plugging the blasting holes from the top, the foam material filling the bottom of the fan-shaped holes of the exploratory filling holes should leave a protective space of at least 50cm from the top bottom opening of the exploratory filling holes.

Images