Sub-section medium-deep hole mining method with top pretreatment under broken ore and rock conditions

Abstract

The present application provides a segmented medium-deep hole mining method with top pretreatment under conditions of broken ore and rock, which belongs to the field of mining. The method constructs rock drilling tunnels in each stope in the adjacent upper segment in advance before mining each stope in the segment to be mined, and pre-supports the rock drilling tunnel. Horizontal blastholes perpendicular to the side of the rock drilling tunnel are constructed at the bottom thereof, and the horizontal blastholes are blasted in an intermittent manner along the direction of the rock drilling tunnel to separate the bottom plate of the adjacent upper segment stope from the top plate of the stope to be mined. The present application combines the top pretreatment of the stope with pre-support, achieving the effect of stabilizing the rock drilling tunnel and the bottom ore pillar in the upper segment stope, avoiding the structural damage and collapse caused by blasting disturbance and empty field when mining in the lower stope under conditions of broken ore and rock; the solution makes the production connection between the upper and lower segment stopes more compact, improves the mining progress and safety of the stope, and has a simple process and high practical application value.

Description

Technical Field

[0001] The invention relates to the technical field of mining, and in particular to a segmented medium-deep hole mining method with top pretreatment under broken ore and rock conditions. Background Art

[0002] Currently, steeply inclined, medium-thick or thicker ore bodies under broken rock conditions are mostly mined using the segmented medium-deep hole and subsequent backfill method, with the overall mining sequence being from bottom to top. While the lower segmented stope is operating, the rock-drilling tunnels at the bottom of the adjacent stope directly above it have already been completed and supported with shotcrete mesh. The advance construction and support of the upper segmented stope rock-drilling tunnels in the segmented medium-deep hole and subsequent backfill method, in part, provides access for the placement of backfill piping in the lower segmented stope, and in part, accelerates the mining and approval process to ensure the stability of the mine's production capacity. However, in actual engineering, due to the influence of broken ore rock conditions and blasting disturbance in the lower sub-level mining area, the drilling tunnels constructed in the upper sub-level are difficult to preserve intact after the completion of the lower sub-level mining area. Even under the support conditions of anchor nets or shotcrete, the drilling tunnels and the triangular pillars on both sides will mostly be destroyed and collapse to a certain extent. The collapsed drilling tunnels will affect the mining progress and safety of the upper sub-level mining area. If they are repaired again, the mining cost will be increased, the economic benefits of ore recovery will be reduced, and the safety risk will be increased.

[0003] A patent discloses a large-structure filling mining method for extremely broken ore bodies with roof reconstruction and side wall reinforcement. The stope is divided into a middle stope, and two upper and lower sections are set in the middle stope, and mining is carried out in steps. First, the top of the section is mined by the downward approach filling mining method, an artificial false roof is constructed, and grouting anchors are used in the second-step stope to support the two sides of the first-step stope, so that the first-step stope forms a relatively stable mining environment. The first-step stope is mined by the upward segmented filling method. After the first-step stope is mined and filled, the second-step stope is mined by the segmented drilling stage empty site followed by filling method. Under the action of the artificial false roof, grouting anchor reinforcement of the side walls and high-strength filling body, this method improves the mining environment of the second-step stope and realizes efficient upward fan-shaped medium-deep hole mining of all ore bodies in the second-step stope. However, this mining method involves constructing grouting anchor cables through the side walls of the stope in the second step, constructing a thick artificial false roof (6 to 8 meters) of filling material on the roof of each stope, and combining it with complex mining technology to reduce the exposure time of the roof. This makes the entire mining project more complicated, the mining efficiency is low, and the ore recovery cost is increased. As a result, its actual application value in the mining of extremely broken ore bodies is relatively low. Summary of the Invention

[0004] In view of the technical problems existing in the background technology, the present application provides a segmented medium-deep hole mining method with top pretreatment under broken ore rock conditions, which aims to solve the technical problem that the constructed tunnels or pillars in the upper segment mining area are easily affected by the lower segment construction during the mining of steeply inclined medium-thick or thicker ore bodies under broken ore rock conditions, resulting in damage or collapse.

[0005] The present application provides a segmented medium-long hole mining method with top pretreatment under broken ore and rock conditions, comprising the following steps:

[0006] S1. Divide the ore body to be mined into sections in height, and mine each section from bottom to top; arrange the stopes for each section along the strike of the ore body, and adopt the mining method of every other stope;

[0007] S2. Before mining each stope in any segment to be mined, construct in advance rock drilling tunnels for each stope in the current segment and each stope in the adjacent upper segment; pre-support the rock drilling tunnel of the upper sub-segment stope adjacent to the stope to be mined, construct horizontal blastholes at the bottom of the stope perpendicular to the side of the rock drilling tunnel, and blast the horizontal blastholes with interval charging along the direction of the rock drilling tunnel to separate the floor of the adjacent upper sub-segment stope from the roof of the stope to be mined;

[0008] S3, blasting and mining the stope in the to-be-mined section by using upward fan-shaped medium-long holes, and immediately backfilling after mining is completed, completing the mining of all the stopes in the to-be-mined section by mining one stope at a time;

[0009] S4. Repeat steps S2 to S3 to continue mining the adjacent upper segmented stopes from bottom to top until the mining of the entire ore body to be mined is completed.

[0010] In the technical solution of the present application, before mining any mining area of ​​each mining area in the segment to be mined, the rock drilling tunnels of each mining area in the adjacent upper segment are constructed in advance, and the rock drilling tunnels are pre-supported. At the bottom of the mining area, horizontal blast holes perpendicular to the side of the rock drilling tunnel are constructed, and the horizontal blast holes are blasted along the direction of the rock drilling tunnel in an intermittent manner to separate the bottom plate of the adjacent upper segment mining area from the top plate of the mining area to be mined. In this way, the rock drilling tunnels and the bottom ore pillars in the upper segment mining area are stabilized, and the mining area is prevented from being affected by the blasting disturbance and the empty field when mining in the lower segment mining area under the condition of broken ore and rock. This solution makes the production connection between the upper and lower segment mining areas more compact, improves the mining progress and safety of the mining area, and has a simple mining process and high practical application value.

[0011] As a further improvement of the present invention, in step S2, the height of the horizontal blasthole constructed at the bottom of the rock drilling tunnel of the adjacent upper sub-level stope is no more than 0.1 m from the bottom plate of the rock drilling tunnel, and the construction length exceeds the boundary of the stope where the rock drilling tunnel is located by 0.3~0.5 m.

[0012] By implementing blasting in a staggered manner on the horizontal blastholes, the setting of uncharged empty holes can act as air intervals during blasting, which is beneficial to controlling the blasting effect, reducing damage to the integrity of the bottom pillars, and preventing the pillars from losing their bottom support function; limiting the distance between the horizontal blastholes and the bottom plate of the rock drilling tunnel and the distance beyond the boundary of the mining area is also for the purpose of controlling the blasting range and effect, so that the bottom plate of the adjacent upper segmented mining area is completely separated from the top plate of the mining area to be mined, thereby avoiding damage to the stability of the mining area.

[0013] As a further improvement of the present invention, in step S3, when the upward fan-shaped medium-deep holes are used for blasting and mining in the mining area to be mined, horizontal shallow holes are used at the same time to blast and mine the triangular pillars on both sides of the rock drilling tunnel at the bottom of the mining area to be mined.

[0014] By using horizontal blastholes to pre-crack the upper and lower boundaries of adjacent segmented stopes, the difficulty of recovering the triangular pillars at the bottom of the stope is reduced, and the recovery completeness of the pillars is improved, so that they can be blasted and recovered together with the normal mining rows; in this way, the overall loss of ore is reduced and the recovery rate of broken ore rock is improved.

[0015] As a further improvement of the present invention, in step S1, the ore body to be mined is a steeply inclined, medium-thick or thicker ore body under conditions of broken ore rock, the ore body has an inclination angle greater than 50°, and the ore body thickness is greater than 5 meters. This technical solution solves the technical problem that when mining a steeply inclined, medium-thick or thicker ore body under conditions of broken ore rock using a sublevel medium-deep hole and subsequent backfill mining method, existing tunnels or pillars in the upper sublevel stope are easily affected by construction work in the lower sublevel stope, resulting in damage or collapse.

[0016] As a further improvement of the present invention, the aperture of the horizontal blasthole is 60-80 mm, the length is 5-6 m, and the row spacing of the horizontal blasthole along the direction of the rock drilling tunnel in which the horizontal blasthole is located is 1.0-1.2 m.

[0017] The above-mentioned horizontal blasthole parameters are set to ensure the blasting effect of the horizontal blasthole, so that it can separate the bottom plate of the adjacent upper segmented mining area from the top plate of the mining area to be mined, without causing damage to the surrounding environment and affecting the normal mining of the ore body.

[0018] As a further improvement of the present invention, in step S2, before mining each stope in the lowest segment of the ore body to be mined, the rock drilling tunnel in the stope is pre-supported, and horizontal blast holes perpendicular to the side of the rock drilling tunnel are constructed at the bottom thereof. The horizontal blast holes are blasted along the direction of the rock drilling tunnel by using intermittent charging to separate the bottom plate of the stope in the segment from the bottom surrounding rock.

[0019] For each stope within the lowest section of the ore body to be mined, horizontal blastholes are also used for pre-splitting blasting to separate the bottom plate of the stope within the section from the bottom surrounding rock, which is beneficial to the stability of the stope recovery and the recovery of the bottom pillars, and avoids the mixing of the bottom surrounding rock, which causes an increase in the depletion rate of the ore.

[0020] As a further improvement of the present invention, the pre-support includes first constructing anchor holes and anchor cable holes on the side walls and top plate of the rock drilling tunnel, installing anchor rods and anchor cables, applying prestress and grouting to the anchor cables, then laying and fixing metal mesh on the inner surface of the rock drilling tunnel, and finally spraying concrete on the inner surface of the rock drilling tunnel.

[0021] The combination of anchor cables and shotcrete mesh supports improves the support effect. Cement is grouting through the anchor cable holes, and the cement penetrates the surrounding rock through the cracks, thereby consolidating the rock layer and strengthening its stability. The anchor cables are prestressed using special equipment, so that the rock layers penetrated by the anchor cables can fit together tightly, thereby strengthening the rock layer and preventing the roadway from collapsing and deforming. Finally, sprayed concrete is used to make the entire roadway more integrated. The tension of the anchor cables can act on the roadway surface as a whole through the metal mesh and the shotcrete layer, protecting the roadway from damage.

[0022] This technical solution combines the two processes of pretreatment and pre-support of the mine top to protect the already constructed rock drilling tunnels and pillars in the upper section from the influence of broken ore and rock conditions and blasting disturbance in the lower section mine, thus solving the technical problem of safe and efficient mining of medium and deep hole mines in the section under broken ore and rock conditions.

[0023] As a further improvement of the present invention, in step S2, before mining each stope of any segment to be mined, it is necessary to set up several ore-exit routes between adjacent stopes, using the rock-drilling roadway as the working surface. The ore-exit routes connect to the rock-drilling roadways of adjacent stopes and have an angle of 40° to 50° with the rock-drilling roadways. In step S1, before mining begins on the ore body to be mined, a mining and cutting process is carried out on the ore body, including segmented transport lanes set between the segments and along the direction of the ore body, and ore chute connecting lanes and ore chute shafts perpendicular to the segmented transport lanes.

[0024] As a further improvement of the present invention, the arrangement of the anchor rod holes and the anchor cable holes is alternately arranged along the direction of the rock drilling tunnel, the anchor rod holes are arranged on the inner surface of the rock drilling tunnel with a mesh size of 1m*1m, the hole diameter is 40~50 mm, and the length of the anchor rod is 1.8~2.2 m; the row spacing of the anchor cable holes is 2.0~2.2 m, the hole diameter is 50~70 mm, and the length is 6~8 m; the mesh size of the metal mesh is 100mm*100mm, and the diameter of its steel bar raw material is 5~8 mm; the thickness of the shotcrete is 25~30 mm.

[0025] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solution of this application, the following is a brief introduction to the drawings used in this application. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort.

[0027] Figure 1 This is a schematic diagram of the stope structure in the Ⅰ-Ⅰ direction in the segmented medium-deep hole mining method with top pretreatment under the condition of broken ore and rock in the embodiment of the present application;

[0028] Figure 2 for Figure 1 Schematic diagram of the stope structure in the middle II-II direction;

[0029] Figure 3 for Figure 1 Schematic diagram of the stope structure in the middle III-III direction;

[0030] Figure 4 The collapse of the rock drilling tunnel and the pillars on both sides in the existing segmented medium-deep hole and subsequent backfill mining method;

[0031] Figure 5 This is a schematic diagram of the arrangement of horizontal blastholes in the segmented medium-deep hole mining method with top pretreatment under the condition of broken ore and rock in an embodiment of the present application;

[0032] Figure 6 This is a schematic diagram of the structure of pre-support in the segmented medium-deep hole mining method with top pretreatment under broken ore and rock conditions in an embodiment of the present application.

[0033] Explanation of the accompanying reference numerals: 100, segment; 110, rock drilling tunnel; 120, horizontal blasthole; 130, upward fan-shaped medium-deep hole; 140, horizontal shallow hole; 151, anchor rod; 152, anchor cable; 160, mine access road; 170, segmented transport tunnel; 180, ore chute connecting tunnel; 190, ore chute; 200, ore; 300, filling body. DETAILED DESCRIPTION

[0034] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0036] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0037] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0038] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0039] For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0040] At present, the medium-thick or thicker ore bodies with steep inclinations under broken ore rock conditions are mostly mined by the segmented medium-deep hole and subsequent backfill mining method, and the overall mining order of the mine is from bottom to top; when the lower segment stope is in production, the rock drilling tunnel at the bottom of the adjacent stope directly above the stope has been completed and has been supported by shotcrete anchor nets. The purpose of the advance construction and support of the rock drilling tunnel in the upper segment stope in the segmented medium-deep hole and subsequent backfill mining method is, on the one hand, to provide a channel for the layout of the backfill pipeline in the lower segment stope, and on the other hand, to speed up the construction progress of the mining project and ensure the stability of the mine's production capacity. However, in actual projects, due to the influence of broken ore rock conditions and blasting disturbance in the lower segment stope, the rock drilling tunnels that have been constructed in the upper segment are difficult to preserve intact after the completion of the lower segment stope. Even under the support conditions of anchor nets or shotcrete, the rock drilling tunnels and the triangular ore pillars on both sides will mostly be destroyed, and a certain degree of collapse will occur (as shown in the attached manual). Figure 4 The collapsed drilling roadway will affect the mining progress and safety of the upper sub-level stope. If it is repaired, the mining cost will be increased, the economic benefits of ore recovery will be reduced, and the safety risk will be increased.

[0041] In order to solve the technical problem that the constructed tunnels or pillars in the upper segmented stope are easily affected by the construction of the lower segmented stope and may be damaged or collapsed when mining the steeply inclined medium-thick or thicker ore body under the current broken ore rock conditions, the present application provides a segmented medium-deep hole mining method with top pretreatment under broken ore rock conditions. Before mining each stope of any segment to be mined, the rock drilling tunnels of each stope in the adjacent upper segment are constructed in advance, and the rock drilling tunnels are pre-supported. Horizontal blast holes perpendicular to the side walls of the rock drilling tunnel are constructed at the bottom of the stope on both sides. The horizontal blast holes are blasted along the direction of the rock drilling tunnel by means of intermittent charging to separate the bottom plate of the adjacent upper segmented stope from the top plate of the stope to be mined. In this way, the rock drilling tunnel and the bottom pillar in the upper segmented stope are stabilized, and the structural damage and collapse caused by the disturbance of blasting in the stope and the empty site when mining in the lower segmented stope under the condition of broken ore and rock are avoided. This scheme makes the production connection between the upper and lower segmented stopes more compact, improves the mining progress and safety of the stope, and the mining process is simple and has high practical application value.

[0042] For the convenience of explanation, the following embodiments are described by taking a segmented medium-deep hole mining method with top pretreatment under broken ore and rock conditions according to an embodiment of the present application as an example.

[0043] Please refer to Figures 1 to 3 The present invention provides a method for segmented medium-long hole mining with top pretreatment under broken ore and rock conditions, comprising the following steps:

[0044] S1. Divide the ore body to be mined into 100 segments in height, and mine each segment 100 from bottom to top; arrange stopes in each segment 100 along the strike of the ore body, and adopt a mining method of mining every other stope;

[0045] S2. Before mining each stope in any of the sections 100 to be mined, construct in advance rock drilling tunnels 110 for each stope in the current section 100 and each stope in the adjacent upper section; pre-support the rock drilling tunnel 110 of the upper sub-section stope adjacent to the stope to be mined, construct horizontal blastholes 120 perpendicular to the side walls of the rock drilling tunnel 110 at its bottom toward both sides of the stope, and blast the horizontal blastholes 120 along the direction of the rock drilling tunnel 110 using intermittent charging to separate the floor of the adjacent upper sub-section stope from the roof of the stope to be mined;

[0046] S3. Blasting and mining are performed on the stope to be mined using upward fan-shaped medium-long holes 130. Filling is performed immediately using the filling body 300 after mining is completed. Mining is completed in all the stopes in the segment to be mined using a one-by-one mining method.

[0047] S4. Repeat steps S2 to S3 to continue mining the adjacent upper segmented stopes from bottom to top until the mining of the entire ore body to be mined is completed.

[0048] This mining method is to construct the rock drilling tunnels 110 of each stope in the adjacent upper segment before mining in each stope of any segment to be mined 100, and pre-support the rock drilling tunnels 110. At the bottom of the stope, horizontal blast holes 120 perpendicular to the side walls of the rock drilling tunnels 110 are constructed on both sides of the stope. The horizontal blast holes 120 are blasted in an intermittent manner along the direction of the rock drilling tunnel 110 to separate the bottom plate of the adjacent upper segment stope from the top plate of the stope to be mined. In this way, the rock drilling tunnels 110 and the bottom ore pillars in the upper segment stope are stabilized, and the rock drilling tunnels 110 are prevented from being disturbed by the blasting of the stope and the empty field when mining in the lower segment stope under the condition of broken ore and rock. This solution makes the production connection between the upper and lower segment stopes more compact, improves the mining progress and safety of the stope, and has a simple mining process and high practical application value.

[0049] See also Figure 5 As shown, in some embodiments, in step S2, the horizontal blasthole 120 constructed at the bottom of the rock tunnel 110 in the adjacent upper sub-stope is no more than 0.1 m above the floor of the rock tunnel 110, and its construction length exceeds the stope boundary of the rock tunnel 110 by 0.3-0.5 m. It should be noted that the height distance between the horizontal blasthole 120 and the floor of the rock tunnel 110 is the distance between the bottom surface of the horizontal blasthole 120 and the surface of the floor of the rock tunnel 110.

[0050] In the technical solution of the embodiment of the present application, blasting is carried out by implementing intermittent charging of the horizontal blastholes 120. The setting of the uncharged empty holes can act as air intervals during blasting, which is beneficial to controlling the blasting effect, reducing the damage to the integrity of the bottom pillars, and avoiding the pillars from losing their bottom support function; limiting the distance between the horizontal blastholes 120 and the bottom plate of the rock drilling tunnel 110 and the distance beyond the boundary of the mining area is also for controlling the blasting range and effect, so that the bottom plate of the adjacent upper segmented mining area is completely separated from the top plate of the mining area to be mined, thereby avoiding damage to the stability of the mining area.

[0051] Furthermore, in some embodiments, in step S3, when the upward fan-shaped medium-deep hole 130 is used for blasting and mining in the mining area to be mined, the horizontal shallow hole 140 is used to blast and mine the triangular pillars on both sides of the rock drilling tunnel 110 at the bottom of the mining area to be mined.

[0052] In the technical solution of the embodiment of the present application, the upper and lower boundaries of the adjacent segmented mining areas 100 are pre-cracked by using horizontal blast holes 120, thereby reducing the difficulty of recovering the triangular pillars at the bottom of the mining area and improving the recovery completeness of the pillars so that they can be blasted and recovered together with the normal mining rows; in this way, the overall loss of ore is reduced and the recovery rate of broken ore rock is improved.

[0053] Furthermore, in some embodiments, in step S1, the ore body to be mined is a steeply inclined, medium-thick or thicker ore body under conditions of broken ore rock, the ore body has an inclination angle greater than 50°, and the ore body thickness is greater than 5 meters. This technical solution solves the technical problem that when mining a steeply inclined, medium-thick or thicker ore body under conditions of broken ore rock using a sub-level medium-deep hole and subsequent backfill mining method, existing tunnels or pillars in the upper sub-level stope are easily affected by construction work in the lower sub-level stope, resulting in damage or collapse.

[0054] Furthermore, in some embodiments, the horizontal blastholes 120 have a diameter of 60-80 mm and a length of 5-6 m, and the spacing of the horizontal blastholes 120 along the direction of the rock drilling tunnel 110 is 1.0-1.2 m.

[0055] In the technical solution of the embodiment of the present application, the setting of the above-mentioned parameters of the horizontal blasthole 120 is to ensure the blasting effect of the horizontal blasthole 120, so that it can separate the bottom plate of the adjacent upper segmented mining area from the top plate of the mining area to be mined without causing damage to the surrounding environment and affecting the normal mining of the ore body.

[0056] Furthermore, in some embodiments, in step S2, before mining each stope in the lowest segment 100 of the ore body to be mined, the rock drilling tunnel 110 in the stope is pre-supported, and horizontal blast holes 120 perpendicular to the side of the rock drilling tunnel 110 are constructed at the bottom thereof, and the horizontal blast holes 120 are blasted along the direction of the rock drilling tunnel 110 by means of intermittent charging to separate the bottom plate of the stope in the segment from the bottom surrounding rock.

[0057] In the technical solution of the embodiment of the present application, horizontal blastholes 120 are also used for pre-splitting blasting of each mining area within the lowest segment 100 of the ore body to be mined, so as to separate the bottom plate of the mining area within the segment from the bottom surrounding rock, which is beneficial to the stability of the mining area and the recovery of the bottom pillars, and avoids the mixing of the bottom surrounding rock, which causes an increase in the depletion rate of the ore.

[0058] See also Figure 6 As shown, in some embodiments, the pre-support includes first constructing anchor holes and anchor cable holes on the side walls and top plate of the rock drilling tunnel 110, installing anchor rods 151 and anchor cables 152, applying prestress and grouting to the anchor cables 152, then laying and fixing metal mesh on the inner surface of the rock drilling tunnel 110, and finally spraying concrete on the inner surface of the rock drilling tunnel 110.

[0059] Furthermore, in some embodiments, the arrangement of anchor holes and anchor cable holes is alternately arranged along the direction of the rock drilling tunnel 110, and the anchor holes are arranged on the inner surface of the rock drilling tunnel 110 with a grid size of 1m*1m, a hole diameter of 40~50 mm, and a length of the anchor rod 151 of 1.8~2.2 m; the row spacing of the anchor cable holes is 2.0~2.2 m, the hole diameter is 50~70 mm, and the length is 6~8 m; the mesh size of the metal mesh is 100mm*100mm, and the diameter of its steel bar raw material is 5~8 mm; the thickness of the shotcrete is 25~30 mm.

[0060] In the technical solution of the embodiment of the present application, a combination of anchor cables 152, anchor rods 151, and sprayed anchor mesh support is employed to enhance support effectiveness. Cement is grouting through the anchor cable holes, allowing the cement to penetrate the surrounding rock formations through the cracks, thereby consolidating the rock formations and enhancing their stability. Anchor cables 152 are prestressed using specialized equipment, allowing the rock formations penetrated by anchor cables 152 to adhere tightly together, thereby reinforcing the rock formations and preventing the tunnel from collapsing and deforming. Finally, concrete is sprayed to enhance the integrity of the entire tunnel. The tension of anchor cables 152 is applied to the tunnel surface through the metal mesh and the sprayed concrete layer, protecting the tunnel from damage.

[0061] This technical solution combines the two processes of pretreatment and pre-support of the mine top to protect the upper segmented rock drilling tunnel 110 and the ore pillars from the influence of the broken ore and rock conditions and the blasting disturbance of the lower segmented mine, thus solving the technical problem of safe and efficient mining of segmented medium and deep hole mines under the existing broken ore and rock conditions.

[0062] Furthermore, in some embodiments, in step S2, before mining begins in each stope of any segment to be mined, it is necessary to set up several ore-discharging access roads 160 between adjacent stopes, using the rock drilling tunnel 110 as the working surface. The ore-discharging access roads 160 are used to discharge the collapsed ore 200. The ore-discharging access roads 160 connect to the rock drilling tunnels 110 of adjacent stopes and are at an angle of 40° to 50° with the rock drilling tunnels 110. In step S1, before mining begins in the ore body to be mined, a mining and cutting process is performed on the ore body, including a staged transport tunnel 170 located between each segment 100 and along the direction of the ore body, and a chute connecting tunnel 180 and a chute shaft 190 perpendicular to the staged transport tunnel 170.

[0063] Specific examples are listed below. It should be noted that the examples described below are illustrative and are only used to explain this application, and should not be understood as limiting this application. If specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in this field or the product instructions shall be followed.

[0064] Example 1

[0065] This embodiment provides a practical application of a segmented medium-deep hole mining method with top pretreatment under broken ore rock conditions to a steeply inclined medium-thick or thicker ore body under certain broken ore rock conditions, including the following steps:

[0066] S1. Divide the ore body to be mined into 100 segments, each 27 m high. Mining of each segment 100 is carried out from bottom to top. Arrange stopes in each segment 100 along the strike of the ore body. The stope width is 15 m. Each stope adopts a stope-by-stop method.

[0067] S2. Before mining each stope in any of the sections 100 to be mined, construct in advance rock drilling tunnels 110 for each stope in the current section 100 and each stope in the adjacent upper section; pre-support the rock drilling tunnel 110 of the upper sub-section stope adjacent to the stope to be mined, construct horizontal blastholes 120 perpendicular to the side walls of the rock drilling tunnel 110 at its bottom toward both sides of the stope, and blast the horizontal blastholes 120 along the direction of the rock drilling tunnel 110 using intermittent charging to separate the floor of the adjacent upper sub-section stope from the roof of the stope to be mined;

[0068] The height of the horizontal blasthole 120 is 0.05 m from the bottom plate of the rock tunnel 110, and the construction length exceeds the boundary of the stope where the rock tunnel 110 is located by 0.5 m. The horizontal blasthole 120 has a diameter of 60 mm and a length of 6 m. The horizontal blasthole 120 is spaced 1.0 m apart along the direction of the rock tunnel 110. The pre-support construction includes first constructing anchor holes and anchor cable holes in the side walls and roof of the rock tunnel 110, installing anchor rods 151 and anchor cables 152, grouting the anchor cable holes and applying prestress to the anchor cables 152, laying and fixing metal mesh on the inner surface of the rock tunnel 110, and finally spraying concrete on the inner surface of the rock tunnel 110.

[0069] Structural parameters of pre-support: anchor holes are constructed according to a 1m*1m grid, with an anchor hole diameter of 42mm. Anchor 151 uses 18mm diameter threaded steel bars with a length of 2m. The anchor cable hole has a diameter of 60mm. Anchor cable 152 uses 21.8mm diameter steel strands with an anchor cable hole length of 7m (the ends of the upward anchor cables 152 are in stable rock formations, and the ends of the sub-horizontal anchor cables 152 are in stable ore rock in adjacent stopes). Six anchor cables 152 are arranged in one anchor cable row, with an anchor cable 152 row spacing of 2m. The steel bar material of the metal mesh has a diameter of 6mm and a grid size of 100mm*100mm. The spacing between anchor cables 151 is 1m, and the spacing between anchor cables 152 rows is 2m. During on-site construction, the rows of anchor cables 152 and anchor rods 151 are staggered along the direction of the rock drilling tunnel 110 to prevent the anchor cable holes and anchor bolt holes from intersecting.

[0070] S3. Blasting and mining are performed on the stope to be mined using upward fan-shaped medium-long holes 130. Simultaneously, horizontal shallow holes 140 are used to blast and mine the triangular pillars on both sides of the rock drilling tunnel 110 at the bottom of the stope to be mined. Backfilling is performed immediately after mining is completed. Mining is completed in all stopes within the section to be mined using a one-by-one mining method.

[0071] S4. Repeat steps S2 to S3 to continue mining the adjacent upper segmented stopes from bottom to top until the mining of the entire ore body to be mined is completed.

[0072] This embodiment combines the two processes of pretreatment and pre-support of the mine top to protect the rock drilling tunnels and pillars constructed in the upper segmented mine from the influence of broken ore and rock conditions and blasting disturbance in the lower segmented mine, making the production connection between the upper and lower segmented mines more compact, improving the mining progress and safety of the mine, reducing the loss of ore as a whole, and improving the recovery rate of broken ore and rock. In addition, the mining process is simple and the practical application value is high.

[0073] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A segmented medium-deep hole mining method with top pretreatment under broken ore and rock conditions, characterized in that: The following steps are involved: S1. Divide the ore body to be mined into sections in height, and mine each section from bottom to top; arrange the stopes for each section along the strike of the ore body, and adopt the mining method of every other stope; S2. Before mining each stope in any segment to be mined, construct in advance rock drilling tunnels for each stope in the current segment and each stope in the adjacent upper segment; pre-support the rock drilling tunnel of the upper sub-segment stope adjacent to the stope to be mined, construct horizontal blastholes at the bottom of the stope perpendicular to the side of the rock drilling tunnel, and blast the horizontal blastholes with interval charging along the direction of the rock drilling tunnel to separate the floor of the adjacent upper sub-segment stope from the roof of the stope to be mined; S3, blasting and mining the stope in the to-be-mined section by using upward fan-shaped medium-long holes, and immediately backfilling after mining is completed, completing the mining of all the stopes in the to-be-mined section by mining one stope at a time; S4, repeating the method of steps S2 to S3 to continue mining the adjacent upper segmented stopes from bottom to top until the mining of the entire ore body to be mined is completed; In step S2, before mining each stope in the lowest segment of the ore body to be mined, pre-support the rock tunnels in the stope, and construct horizontal blastholes perpendicular to the side walls of the rock tunnels at their bottoms. The horizontal blastholes are blasted along the direction of the rock tunnels using intermittent charging to separate the floor of the stope in the segment from the bottom surrounding rock. In step S2, before mining any stope in any segment to be mined, it is necessary to use the rock drilling tunnel as the working surface and set up several mining access roads between adjacent stopes. The mining access roads are connected to the rock drilling tunnels of adjacent stopes, and the angle between the mining access roads and the rock drilling tunnels is 40°~50°.

2. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S2, the horizontal blasthole constructed at the bottom of the rock drilling tunnel of the adjacent upper sub-level stope has a height not exceeding 0.1 m from the bottom plate of the rock drilling tunnel, and a construction length exceeding the boundary of the stope where the rock drilling tunnel is located by 0.3-0.5 m.

3. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S3, while the upward fan-shaped medium-long holes are used for blasting and mining the stope to be mined, horizontal shallow holes are used for blasting and mining the triangular pillars on both sides of the rock drilling tunnel at the bottom of the stope to be mined.

4. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S1, the ore body to be mined is a steeply inclined medium-thick or thicker ore body under broken ore rock conditions, the ore body inclination angle of the steeply inclined medium-thick or thicker ore body is greater than 50°, and the ore body thickness is greater than 5 m.

5. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 2, characterized in that: The aperture of the horizontal blasthole is 60-80 mm, the length is 5-6 m, and the row spacing of the horizontal blasthole along the direction of the rock drilling tunnel in which the horizontal blasthole is located is 1.0-1.2 m.

6. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 5, characterized in that: The pre-support includes first constructing anchor holes and anchor cable holes on the side walls and top plate of the rock drilling tunnel, installing anchor rods and anchor cables, applying prestress and grouting to the anchor cables, then laying and fixing metal mesh on the inner surface of the rock drilling tunnel, and finally spraying concrete on the inner surface of the rock drilling tunnel.

7. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 1, characterized in that: In step S1, before the mining of the ore body to be mined begins, the ore body is mined and cut, including segmented transport tunnels set between the segments and along the direction of the ore body, and ore chute connecting tunnels and ore chute shafts perpendicular to the segmented transport tunnels.

8. The method for segmented medium-long hole mining under top pretreatment under broken ore and rock conditions according to claim 6, characterized in that: The anchor holes and anchor cable holes are arranged alternately along the direction of the rock drilling tunnel. The anchor holes are arranged on the inner surface of the rock drilling tunnel with a mesh size of 1m*1m, a hole diameter of 40~50 mm, and a length of 1.8~2.2 m; the row spacing of the anchor cable holes is 2.0~2.2 m, the hole diameter is 50~70 mm, and the length is 6~8 m; the mesh size of the metal mesh is 100mm*100mm, and the diameter of its steel bar raw material is 5~8 mm; the thickness of the shotcrete is 25~30 mm.

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