Method for drawing ore from steeply inclined medium-thick ore body

Abstract

The present application provides a kind of steeply inclined medium-thick ore body falling method, comprising the following steps: arranging stope along the trend of ore body, cutting lane is constructed in the upper part of stope, and ore receiving lane is constructed in the bottom of stope, and ore receiving lane is constructed based on the position of ore receiving lane; Cutting well is constructed in cutting lane, and first fan-shaped deep hole is arranged on the inner side wall of cutting well along the thickest position of ore body, cutting groove is formed on cutting well by expanding slot blasting on first fan-shaped deep hole, and the cutting ore produced by expanding slot blasting falls into the ore receiving lane; Downward inclined fan-shaped hole with an inclination angle of 80-86° is arranged on the cutting groove, and the ore in the cutting groove is blasted into the ore receiving lane by stoping blasting on the downward inclined fan-shaped hole. The present application can solve the problems in the prior art, such as the need for construction of multiple drilling galleries for segmented perforation, low work efficiency, the need for stripping waste rock at the top and bottom of the drilling chamber, and high ore dilution rate.

Description

Technical Field

[0001] This invention relates to the field of mining construction technology, and more specifically, to a method for mining ore from a steeply inclined, medium-thick ore body. Background Technology

[0002] Most mineral resource extraction has now moved to underground mining. With the development of blasting technology, deep-hole blasting has been widely used in underground mining, characterized by large-scale blasting and high efficiency, and is suitable for large-scale mechanized and intelligent mining.

[0003] Currently, most underground mines with steeply dipping, medium-thick ore bodies use medium-deep hole quarrying, which requires the construction of multiple drilling tunnels for segmented drilling, resulting in low work efficiency. On the other hand, some mines use vertical deep hole quarrying, which requires the construction of drilling chambers at the top, and waste rock needs to be stripped from the hanging wall and footwall, resulting in a higher ore dilution rate. Summary of the Invention

[0004] In view of the above problems, the purpose of this invention is to provide a method for mining steeply inclined medium-thick ore bodies, so as to solve the problems of low work efficiency caused by the use of medium-deep hole mining in the prior art, which requires the construction of multiple drilling tunnels for segmented drilling; and the use of vertical deep hole mining, which requires the construction of drilling chambers at the top and the stripping of waste rock at the upper and lower plates, resulting in a large ore dilution rate.

[0005] This invention provides a method for extracting ore from a steeply dipping, medium-thick ore body, comprising the following steps:

[0006] S1. Arrange the mining area along the strike of the ore body, construct a cutting roadway in the upper part of the mining area, construct a receiving roadway in the bottom of the mining area, and construct an ore extraction roadway based on the location of the receiving roadway.

[0007] S2. Construct a cutting well in the cutting tunnel, and arrange a first fan-shaped deep hole along the thickest part of the ore body on the inner wall of the cutting well. By expanding the groove of the first fan-shaped deep hole by blasting, a cutting groove is formed on the cutting well, and the cutting ore body generated by the expanding groove blasting falls into the receiving tunnel.

[0008] S3. Arrange downward inclined fan-shaped holes with an inclination angle of 80-86° on the cutting groove, and blast the downward inclined fan-shaped holes to break the ore body in the cutting groove into a ore body that falls into the receiving roadway.

[0009] S4. The cut ore body and the recycled ore body in the receiving tunnel are transported out of the mining area through the ore exit tunnel.

[0010] Furthermore, a preferred embodiment is that the horizontal thickness of the ore body is 18-20m; and the dip angle of the ore body is 60-90°.

[0011] Furthermore, a preferred embodiment is that the construction method for the cutting well includes:

[0012] At least three layers of blast holes are constructed within the cutting tunnel: an outer layer of blast holes consisting of at least six blast holes, a middle layer of blast holes consisting of at least six blast holes arranged inside the outer layer of blast holes, and a vertical deep hole arranged in the middle of the middle layer of blast holes; wherein the outer layer of blast holes and the middle layer of blast holes are arranged in a circular pattern.

[0013] The vertical deep hole is used as an empty hole, and other blast holes are blasted in the height direction using a layered blasting method to form a well, so as to obtain a cutting well.

[0014] Furthermore, a preferred embodiment is that, in the outer layer of boreholes, the diameter of each borehole is 4±0.5m, and the distance between adjacent boreholes is 2±0.5m;

[0015] In the intermediate-level boreholes, the diameter of each borehole is 2±0.5m, and the distance between adjacent boreholes is 1±0.5m;

[0016] The diameter of the vertical deep hole is 1.5-2m.

[0017] Furthermore, a preferred embodiment is that the vertical deep hole is used as an empty hole, and other blast holes are blasted in a layered blasting manner in the height direction to obtain a cut well, including:

[0018] The vertical deep holes are treated as empty holes and no explosive charge is applied. The single charge length of each of the other holes is 0.5-1m and the charge weight is 18kg. The lower part of the holes is plugged with rock powder with a plugging length of 0.5±0.1m.

[0019] After the explosive charge is applied, the blast holes are detonated one by one using digital electronic detonators and detonating cords. The height of each blast is 2±0.5m, until the preset height of the cutting well is reached, thus obtaining the cutting well.

[0020] Furthermore, a preferred embodiment is that the blasting for widening the groove in the first sector-shaped deep hole includes:

[0021] An inclined first sector-shaped deep hole is constructed on one side of the upper plate in the cutting well, and a vertical first sector-shaped deep hole perpendicular to the cutting well is constructed on one side of the lower plate.

[0022] The inclined first sector deep hole and the vertical first sector deep hole are charged with explosives in an intermittent manner to obtain the deep hole to be blasted;

[0023] The deep holes to be blasted are detonated one by one in the width direction using a layered blasting method until the distance between the blasted cutting groove and the upper and lower plates of the ore body reaches the preset ore retention thickness, thus completing the trenching blasting.

[0024] Furthermore, in a preferred embodiment, the row spacing of the inclined first sector-shaped deep holes is 1±0.5m, and the hole spacing is 2.5±0.5m; the row spacing of the vertical first sector-shaped deep holes is 2.5±0.5m, and the hole spacing is 2.5±0.5m.

[0025] Furthermore, a preferred embodiment is that, during the process of loading explosives into the inclined first sector-shaped deep hole and the vertical first sector-shaped deep hole using an intermittent charging method to obtain the deep hole to be blasted,

[0026] The spacing between each charge layer is three rows of holes; each charge is 18 kg; the bamboo poles are spaced 1.5 m apart; the lower part of the deep hole to be blasted is plugged with rock powder, with a plugging length of 0.8 m.

[0027] Furthermore, a preferred approach is that, during the process of sequentially initiating the detonation of the deep hole to be blasted using a layered blasting method in the width direction,

[0028] The deep holes to be blasted are detonated one by one using digital electronic detonators and detonating cord.

[0029] Furthermore, a preferred embodiment is that during the blasting process of mining through the downwardly inclined fan-shaped holes,

[0030] The explosive charge is loaded from the top of the mining area, with a charge density of 1 ± 0.5 g / cm³. 3 The bottom of the downwardly inclined fan-shaped hole is plugged with a spherical plug, and the plugging length of the opening of the downwardly inclined fan-shaped hole is 0.8 to 1.5 m.

[0031] As can be seen from the above technical solution, the ore-cutting method for steeply inclined medium-thick ore bodies provided by this invention ensures the width of the cutting groove by arranging it along the thickest part of the ore body. This ensures the width of the mining area during normal mining and reduces the loss rate. The cutting roadway replaces the mining chamber in the prior art, and combined with the downward-inclined fan-shaped holes used in the mining blasting process, it reduces the difficulty of mining and cutting construction, lowers the exposed area of ​​the roof, improves mining safety, and comprehensively reduces the mining-cutting ratio. The use of downward-inclined fan-shaped holes with an inclination angle of 80-86° for mining blasting reduces construction difficulty and utilizes the safety of the slope formed after blasting, making personnel and equipment safer and more reliable during blasting operations. After blasting, a blasting slope can be formed according to the angle of the blast holes, reducing the risk of floor collapse in the roadway, making the charging operation safer and more reliable, and effectively controlling the ore thickness of the hanging wall and footwall, thereby effectively controlling ore dilution.

[0032] To achieve the foregoing and related objectives, one or more aspects of the invention include the features that will be described in detail below. The following description and accompanying drawings illustrate certain exemplary aspects of the invention. However, these aspects indicate only a few of the various ways in which the principles of the invention can be used. Furthermore, the invention is intended to encompass all such aspects and their equivalents. Attached Figure Description

[0033] Other objects and results of the invention will become more apparent and readily understood with reference to the following description taken in conjunction with the accompanying drawings. In the drawings:

[0034] Figure 1 A flowchart of a ore-cutting method for a steeply dipping, medium-thick ore body according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the mining area layout according to an embodiment of the present invention;

[0036] Figure 3 for Figure 2 An enlarged view of part A;

[0037] Figure 4 for Figure 2 A schematic diagram of the structure in the 1-1 direction;

[0038] Figure 5 for Figure 2 Schematic diagram of the structure in the 2-2 direction;

[0039] Figure 6 for Figure 2 A schematic diagram of the structure in the 3-3 direction;

[0040] Figure 7 This is a diagram showing the arrangement of blast holes during well cutting construction according to an embodiment of the present invention.

[0041] In all the accompanying drawings, the same reference numerals indicate similar or corresponding features or functions. Detailed Implementation

[0042] In the following description, numerous specific details are set forth for illustrative purposes and to provide a thorough understanding of one or more embodiments. However, it will be apparent that these embodiments may also be implemented without these specific details.

[0043] To address the problems of existing technologies, such as the use of medium-deep hole ore cutting, which requires the construction of multiple drilling tunnels for segmented drilling and has low work efficiency, and the use of vertical deep hole ore cutting, which requires the construction of drilling chambers at the top and the stripping of waste rock at the hanging wall and footwall, resulting in a large ore dilution rate, a ore cutting method for steeply inclined medium-thick ore bodies is proposed.

[0044] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0045] To illustrate the ore extraction method for steeply dipping, medium-thick ore bodies provided by this invention. Figure 1 The flowchart of a method for extracting ore from a steeply inclined, medium-thick ore body according to an embodiment of the present invention is shown; Figure 2 The layout of the mining area according to an embodiment of the present invention is shown; Figure 3 It shows Figure 2 An enlarged structure of part A; Figure 4 It shows Figure 2 Structure in the 1-1 direction; Figure 5 It shows Figure 2 Structure in the 2-2 direction; Figure 6 It shows Figure 2 Structure in the 3-3 direction; Figure 7 The arrangement of blast holes during well cutting construction according to an embodiment of the present invention is shown.

[0046] like Figures 1 to 7 As shown in the figure, the ore extraction method for steeply dipping, medium-thick ore bodies provided by the present invention includes the following steps:

[0047] Step S1: Arrange the mining area along the strike of the ore body, construct the cutting roadway at the top of the mining area, construct the receiving roadway at the bottom of the mining area, and construct the exit roadway based on the location of the receiving roadway.

[0048] Specifically, steeply dipping, medium-thick ore bodies are inclined ore bodies. The upper end of the inclined ore body is called the hanging wall, and the lower end is called the footwall. The stope is arranged along the strike of the ore body, that is, between the hanging wall and footwall. In existing technologies, the arrangement of the stope generally requires the construction of mining chambers in the upper part, with downward deep holes drilled within the mining chambers. Cutting shafts are obtained through blasting in these downward deep holes. At the bottom of the stope, a ore-receiving shaft (or ore-dropping shaft) is constructed to receive the ore body generated by cutting and mining blasting. The ore body is then transported out through an ore-dropping roadway constructed at the bottom of the stope. In the method provided by this invention, a cutting roadway is constructed in the upper part of the stope instead of the mining chambers in the existing technology. Combined with the ore-dropping method using downwardly inclined fan-shaped holes in the method provided by this invention, the difficulty of mining and cutting is reduced. It is more applicable to surrounding rock with poor stability and can reduce support-related work. Furthermore, the roadway-type stope has lower construction costs and a smaller mining-to-cutting ratio than the chamber-type stope. The original width of the rock drilling chamber was the width of the mining area, which was generally 15m. After changing to the mining method of inclined downward fan-shaped deep holes, the width of the rock drilling roadway was 5m, which reduced the exposed area of ​​the roof, improved the safety of mining, and comprehensively reduced the mining-to-cutting ratio.

[0049] The cutting roadway is constructed using drilling and rock drilling methods; the receiving roadway is arranged along the stope within the vein, and the ore extraction roadway is arranged along the stope outside the vein; furthermore, the bottom of the stope is constructed using a medium-deep hole method to form a flat-bottomed trench, thus creating the ore extraction structure. The ore extraction structure includes ore extraction roadways for transport equipment, such as vehicles, to enter and exit the bottom of the stope, and connecting roadways for connecting the receiving roadway and the ore extraction roadway. Each of the ore extraction roadway, receiving roadway, and connecting roadway includes both inlet and outlet routes. The method provided by this invention does not impose specific limitations on the specific structural arrangement of the receiving roadway, connecting roadway, and ore extraction roadway in the stope, as long as it ensures that the ore generated by cutting blasting and backfilling blasting can fall into the receiving roadway and be smoothly transported out through the ore extraction roadway.

[0050] In a preferred embodiment of the present invention, the horizontal thickness of the ore body is 18-20m; the dip angle of the ore body is 60-90°. Preferably, the horizontal thickness of the ore body is 18m; the dip angle is preferably 69°, but other thicknesses and dip angles are also possible and are not specifically limited here. The ore extraction method provided by the present invention is applicable to steeply dipping, medium-thick ore bodies with a horizontal thickness of 15-20m and a dip angle of 60-90°. Fan-shaped deep holes are used for downward ore extraction, and to ensure the safety of the extraction operation, the forward inclination angle of the fan-shaped deep holes is 85°. The stope is arranged along the strike of the ore body. When constructing the cutting shaft, the deep hole face of the stope is perpendicular to the strike of the ore body, and the preferred deep hole extraction height is 45m.

[0051] S2. Construct a cutting shaft in the cutting tunnel, and arrange the first fan-shaped deep hole along the thickest part of the ore body on the inner wall of the cutting shaft. By expanding the groove of the first fan-shaped deep hole by blasting, a cutting groove is formed on the cutting shaft, and the cutting ore body generated by the expansion blasting falls into the receiving tunnel.

[0052] Specifically, when constructing a cutting shaft within a cutting tunnel, a widening blast is required during the initial cutting blast. At this stage, blast holes can be drilled within the cutting tunnel to create a cutting groove. Subsequent widening blasts are then carried out within the cutting shaft. Examples of specific methods for constructing cutting shafts and cutting grooves are as follows:

[0053] For the construction of cutting wells and cutting slots, the preferred diameter for deep holes is φ165mm. A T150 down-the-hole drill rig is used for rock drilling. The deep holes of the cutting wells penetrate vertically through the stope height and also serve as drainage boreholes. Because the cutting wells need to penetrate into the surrounding rock, drilling control is strengthened during the drilling process to prevent stope depletion. This includes: 1) ensuring drilling quality and preventing excessive deviation; and 2) measuring and identifying the orebody boundaries during drilling and completing geological logging. A KQG-100 down-the-hole drill rig is used for construction. The deep holes are in a forward-inclined fan shape. On-site construction requires first fixing the rotation center, then determining the face angle based on the vertical direction, and finally determining the azimuth of each borehole based on the vertical direction and center azimuth. The difficulty in deep hole construction in the stope lies in determining the azimuth angle, ensuring construction quality during construction, and promptly conducting borehole inclination measurements after drilling to check the quality of the inclined holes.

[0054] As a preferred embodiment of the present invention, the construction method for cutting wells includes:

[0055] At least three layers of blast holes are constructed within the cutting tunnel: an outer layer of blast holes consisting of at least six blast holes, a middle layer of blast holes consisting of at least six blast holes arranged inside the outer layer of blast holes, and a vertical deep hole arranged in the middle of the middle layer of blast holes; wherein the outer layer of blast holes and the middle layer of blast holes are arranged in a circular pattern.

[0056] The vertical deep holes are used as empty holes, while other blast holes are blasted in layers along the height direction to form wells, so as to obtain cutting wells.

[0057] As a preferred embodiment of the present invention, in the outer layer of boreholes, the diameter of each borehole is 4±0.5m and the distance between adjacent boreholes is 2±0.5m; in the middle layer of boreholes, the diameter of each borehole is 2±0.5m and the distance between adjacent boreholes is 1±0.5m; and the diameter of the vertical deep hole is 1.5-2m.

[0058] In a preferred embodiment of the present invention, the vertical deep hole is used as an empty hole, and other blast holes are blasted in a layered blasting manner in the height direction to obtain a cut well, including:

[0059] The vertical deep holes are treated as empty holes and no explosive charge is applied. The single charge length of each of the other holes is 0.5-1m, and the charge weight is 18kg. The lower part of the holes is plugged with rock powder, with a plugging length of 0.5±0.1m.

[0060] After the explosive charge is applied, the blast holes are detonated one by one using digital electronic detonators and detonating cords. The height of each blast is 2±0.5m until the preset height of the cutting well is reached, thus obtaining the cutting well.

[0061] Specifically, the well cutting adopts a layered blasting method, mainly consisting of borehole probing, hole plugging, charging, and blasting. For example, spherical explosive charges are used, with a length-to-diameter ratio of ≤6:1, a single charge length of 0.8m, and a charge weight of 18kg. The lower part is plugged with rock powder for a length of 0.5m. The well cutting diameter is φ4m, with a hollow center hole. Digital electronic detonators and detonating cord are used for initiation, with each hole detonated sequentially, and a layered blasting height of 2m.

[0062] As a preferred embodiment of the present invention, the blasting process for widening the groove in the first sector-shaped deep hole includes:

[0063] An inclined first sector-shaped deep hole is constructed on one side of the upper plate in the cutting well, and a vertical first sector-shaped deep hole is constructed on one side of the vertical cutting well.

[0064] The inclined first sector deep hole and the vertical first sector deep hole are charged with explosives in an intermittent manner to obtain the deep hole to be blasted;

[0065] The deep holes to be blasted are detonated one by one in the width direction using a layered blasting method until the distance between the blasted cutting groove and the hanging wall and the footwall of the ore body reaches the preset ore retention thickness, thus completing the trenching blast.

[0066] As a preferred embodiment of the present invention, the row spacing of the inclined first sector-shaped deep holes is 1±0.5m and the hole spacing is 2.5±0.5m; the row spacing of the vertical first sector-shaped deep holes is 2.5±0.5m and the hole spacing is 2.5±0.5m.

[0067] As a preferred embodiment of the present invention, in the process of loading explosives into the inclined first sector-shaped deep hole and the vertical first sector-shaped deep hole using an intermittent charging method to obtain the deep hole to be blasted,

[0068] The spacing between each charge layer is three rows of holes; each charge is 18 kg; the bamboo poles are spaced 1.5 m apart; the lower part of the deep hole to be blasted is plugged with rock powder, with a plugging length of 0.8 m.

[0069] As a preferred embodiment of the present invention, in the process of sequentially initiating detonation of the deep holes to be blasted using a layered blasting method in the width direction,

[0070] Digital electronic detonators and detonating cords are used to initiate detonation hole by hole in the deep holes to be blasted.

[0071] Specifically, after the cutting well blasting is completed, widening blasting is carried out. The cutting groove is blasted in stages along its length (width), with each blasting step consisting of three rows of holes. An intermittent charging mode is used, with 18 kg of explosives charged per layer. Bamboo poles are spaced 1.5 m apart, and the bottom is plugged with rock powder for a length of 0.8 m. Digital electronic detonators and detonating cords are used for initiation, with each hole detonated sequentially. During the stope cutting process, to prevent ore dilution, 1 m of ore is left in the footwall and 1.5 m in the hanging wall, depending on the ore and rock distribution, and the ore and rock are detonated separately.

[0072] S3. Arrange downward inclined fan-shaped holes with an inclination angle of 80-86° on the cutting groove, and blast the downward inclined fan-shaped holes to break the ore body in the cutting groove into a ore body that falls into the receiving roadway.

[0073] Specifically, the downward-sloping fan-shaped boreholes are optimized, with an inclination angle of 80-86°. This reduces the difficulty of borehole construction and leverages the safety of the resulting slope after blasting, making personnel and equipment safer and more reliable during blasting operations. After blasting, a blasting slope can be formed based on the borehole angle, reducing the risk of floor collapse in the roadway and making the charging process safer and more reliable. After the cutting groove is formed in the stope, the fan-shaped deep boreholes are blasted, with explosives charged from the top of the stope at a charge density of 1 g / cm³. 3 The bottom of the borehole is plugged with a spherical plug. The plugging length of the fan-shaped deep borehole opening is 0.8-1.5m. The blasting process includes borehole measurement → plugging → charging → blasting. Ammonium oil granular explosive is used for continuous charging. The opening is filled with an initiating charge, and digital electronic detonators are used for initiation. Each borehole is detonated sequentially, with each blasting step consisting of two rows of holes.

[0074] As a preferred embodiment of the present invention, during the blasting process of mining through downwardly inclined fan-shaped holes...

[0075] The top charge is located in the extraction site, and the charge density is 1 ± 0.5 g / cm³. 3 The bottom of the downwardly inclined fan-shaped hole is plugged with a spherical plug, and the plugging length of the opening of the downwardly inclined fan-shaped hole is 0.8 to 1.5 m.

[0076] As a preferred embodiment of the present invention, the downward inclined fan-shaped holes are arranged in a staggered arrangement with small spacing. Each row of fan-shaped deep holes is divided into rows A and B, staggered by 0.3m. While ensuring the hole spacing to avoid perforation, it can increase the amount of ore recovered from the bottom, improve the recovery rate, and achieve good blasting charging effect.

[0077] S4. The cut ore body and the recycled ore body in the receiving roadway are transported out of the mining area through the exit roadway.

[0078] A 4m can be used when extracting ore. 3 The loader extracts ore from the entrance in a centralized manner, ensuring timely ore removal after each blast to guarantee blast compensation space and personnel safety.

[0079] The method provided by this invention involves setting up a stope cutting project. The cutting groove is positioned along the thickest part of the ore body to ensure its width, guaranteeing the mining width during normal stope mining and reducing loss rate. The cutting shaft uses large-diameter deep holes to ensure drilling accuracy. Blasting operations utilize pre-formed spherical explosive charges to ensure the well completion effect and construction efficiency. The widening of the cutting groove employs a combination of parallel vertical deep holes and parallel inclined holes, ensuring the quality of deep hole formation, reducing ore dilution, and increasing borehole utilization. The rational and efficient completion of the stope cutting project prepares the ground for the formation of lateral blasting free faces and compensation space.

[0080] As can be seen from the above specific embodiments, the ore-cutting method for steeply inclined medium-thick ore bodies provided by the present invention ensures the width of the cutting groove by arranging the cutting groove along the thickest part of the ore body. This ensures the width of the mining operation during normal mining and reduces the loss rate. The cutting roadway replaces the mining chamber in the prior art, and combined with the downward-inclined fan-shaped holes used in the mining blasting process, it reduces the difficulty of mining and cutting construction, reduces the exposed area of ​​the roof, improves mining safety, and comprehensively reduces the mining-cutting ratio. The use of downward-inclined fan-shaped holes with an inclination angle of 80-86° for mining blasting reduces construction difficulty and utilizes the safety of the slope formed after blasting, making personnel and equipment safer and more reliable during blasting operations. After blasting, a blasting slope can be formed according to the angle of the blast holes, reducing the risk of floor collapse in the roadway. The charging operation is safer and more reliable, and it can effectively solve the problem of controlling the ore thickness of the hanging wall and footwall, thereby effectively controlling ore dilution.

[0081] The method for mining steeply dipping, medium-thick ore bodies according to the present invention has been described above by way of example with reference to the accompanying drawings. However, those skilled in the art should understand that various modifications can be made to the method for mining steeply dipping, medium-thick ore bodies according to the present invention without departing from the scope of the invention. Therefore, the scope of protection of the present invention should be determined by the contents of the appended claims.

Claims

1. A method for extracting ore from a steeply dipping, medium-thick ore body, characterized in that, Includes the following steps: S1. Arrange the mining area along the strike of the ore body, construct a cutting roadway in the upper part of the mining area, construct a receiving roadway in the bottom of the mining area, and construct an ore extraction roadway based on the location of the receiving roadway. S2. Construct a cutting shaft within the cutting tunnel, and arrange a first fan-shaped deep hole along the thickest part of the ore body on the inner wall of the cutting shaft. Form a cutting groove on the cutting shaft by enlarging the first fan-shaped deep hole with blasting, and allow the cut ore body generated by the enlarging blasting to fall into the receiving tunnel; wherein, the construction method of the cutting shaft includes: At least three layers of blast holes are constructed within the cutting tunnel: an outer layer of blast holes consisting of at least six blast holes, a middle layer of blast holes consisting of at least six blast holes arranged inside the outer layer of blast holes, and a vertical deep hole arranged in the middle of the middle layer of blast holes; wherein the outer layer of blast holes and the middle layer of blast holes are arranged in a circular pattern. The vertical deep hole is used as an empty hole, and other blast holes are blasted in the height direction by layered blasting to form wells, so as to obtain a cutting well; The blasting process for widening the first sector-shaped deep hole includes: An inclined first sector-shaped deep hole is constructed on one side of the upper plate in the cutting well, and a vertical first sector-shaped deep hole is constructed on one side of the lower plate. The inclined first sector deep hole and the vertical first sector deep hole are charged with explosives in an intermittent manner to obtain the deep hole to be blasted; The deep holes to be blasted are detonated one by one in the width direction using a layered blasting method until the distance between the cutting groove formed by the blast and the upper and lower plates of the ore body reaches the preset ore retention thickness, thus completing the trenching blasting. S3. Arrange downward inclined fan-shaped holes with an inclination angle of 80-86° on the cutting groove, and blast the downward inclined fan-shaped holes to break the ore body in the cutting groove into a ore body that falls into the receiving roadway. S4. The cut ore body and the recycled ore body in the receiving tunnel are transported out of the mining area through the ore exit tunnel.

2. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, The horizontal thickness of the ore body is 18-20m; the dip angle of the ore body is 60-90°.

3. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, In the outer layer of boreholes, the diameter of each borehole is 4±0.5 m, and the distance between adjacent boreholes is 2±0.5 m; In the intermediate-level boreholes, the diameter of each borehole is 2±0.5 m, and the distance between adjacent boreholes is 1±0.5 m. The diameter of the vertical deep hole is 1.5-2 m.

4. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, The method of using the vertical deep hole as an empty hole and blasting other blast holes in the height direction using a layered blasting method to obtain a cut well includes: The vertical deep holes are treated as empty holes and no explosive charge is applied. The single charge length of each of the other holes is 0.5-1 m and the charge amount is 18 kg. The lower part of the holes is plugged with rock powder with a plugging length of 0.5 ± 0.1 m. After the explosive charge is applied, the blast holes are detonated one by one using digital electronic detonators and detonating cords. The height of each blast is 2±0.5 m, until the preset height of the cutting well is reached, thus obtaining the cutting well.

5. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, The spacing between the inclined first sector-shaped deep holes is 1±0.5 m, and the hole spacing is 2.5±0.5 m; The vertical first sector-shaped deep holes have a row spacing of 2.5±0.5m and a hole spacing of 2.5±0.5m.

6. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, In the process of loading explosives into the inclined first sector-shaped deep hole and the vertical first sector-shaped deep hole using an intermittent charging method to obtain the deep hole to be blasted, The spacing between each charge layer is three rows of holes; each charge is 18 kg; the bamboo poles are spaced 1.5 m apart; the lower part of the deep hole to be blasted is plugged with rock powder, with a plugging length of 0.8 m.

7. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, During the process of sequentially initiating the detonation of the deep hole to be blasted using a layered blasting method in the width direction. The deep holes to be blasted are detonated one by one using digital electronic detonators and detonating cord.

8. The method for extracting ore from a steeply dipping, medium-thick ore body according to claim 1, characterized in that, During the process of blasting for mining through the downwardly inclined fan-shaped holes. The explosive charge is loaded from the top of the mining area, with a charge density of 1 ± 0.5 g / cm³. 3 The bottom of the downwardly inclined fan-shaped hole is plugged with a spherical plug, and the plugging length of the opening of the downwardly inclined fan-shaped hole is 0.8~1.5m.

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