Medium-length hole mining method for multidirectional space curtain under hanging wall complex sudden water gushing condition

Abstract

The invention provides a medium-length hole mining method for a multidirectional space curtain under the hanging wall complex water inrush condition, and belongs to the field of underground mine exploiting.The medium-length hole mining method for the multidirectional space curtain under the hanging wall complex water inrush condition comprises the following steps that an ore body is divided, and the position of a water-containing body of the ore body is detected; and the common mining areas on the two sides of the water disaster mining area are stoped and filled, three-direction upper disc curtains and four-direction bottom plate curtains are formed in the upper disc curtains and the bottom plate curtains of the water disaster mining area through grouting, and the water disaster mining area is stoped. After the multidirectional space curtain is formed, mining is conducted through the medium-length hole technology with the large production capacity, safe and efficient mining under the complex water burst condition is achieved, the mining method is safe, reliable and flexible in technology, the hole arrangement scheme can be adjusted at any time according to the ore body and the water burst condition, the grouting cost is saved to the maximum extent, and the mining efficiency is improved. The method improves the ore extraction rate, reduces the loss and dilution rate, increases the resource utilization rate of mines, and has great significance for mines threatened by water disasters.

Description

Technical Field

[0001] The invention relates to the technical field of underground mining, and in particular to a multi-directional space curtain medium-deep hole mining method under complex sudden water inrush conditions in the upper plate. Background Art

[0002] The coastal areas of Jiaodong Peninsula in my country are rich in gold geological resources and have become the main gold supply area in the country. In addition to the typical problems faced by deep mines due to the depth of mining, the special geographical location near the sea and the objective conditions of structural fissures make the coastal deep mines affected by major geological disasters such as underground water inrush. Major water inrush accidents can easily cause well flooding, production suspension, loss of manpower and material resources, slow down the speed of excavation and mining, and seriously restrict the economic benefits of mines.

[0003] Curtain grouting is a conventional method to isolate underground water and control water hazards. At present, curtain grouting mainly includes "constructing L-shaped grouting interception curtain", "water-saving mining method of segmented grouting curtain in aquifer" and "three-way advanced curtain grouting method in mining approach". Although it has certain guiding significance for water gushing control, its common problems are that the water gushing situation is simple and there are few water outlets. The curtain can be constructed in the form of "single plane", and its ore body has good occurrence conditions, so it does not require complex mining technology to complete the mining of the ore body. However, when there is a water-conducting fault zone connected to the seawater in the upper plate of the ore body, and the hydrogeology is in extremely complex conditions, there may be sudden water gushing points in the exposed working space top and bottom plates, two sides, and the face. The existing curtain can no longer meet the production and safety needs. The ore body mining is always threatened by water hazards, and tunnel excavation is difficult. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides a multi-directional space curtain medium-deep hole mining method with complex sudden water inrush conditions in the upper plate, aiming to solve the technical problem that the existing curtain grouting method cannot meet the effective mining of ore bodies with extremely complex hydrogeology.

[0005] The present application provides a method for multi-directional space curtain medium-deep hole mining under complex water inrush conditions in the upper plate, comprising the following steps: S1. Divide the ore body into middle sections along the vertical height, and divide the middle sections into subsections. Mining is carried out from top to bottom with the middle sections as units, and auxiliary ramps are excavated in the footwall to connect different middle sections and subsections; S2, detecting the location of the water-bearing body in the ore body, dividing the middle section along the ore body strike into a water-damaged mining area and a first common mining area and a second common mining area located on both sides of the water-damaged mining area; excavating a segmented horizontal tunnel along the ore body strike in the lower wall, mining and filling the first common mining area and the second common mining area, forming a one-way filling curtain and a two-way filling curtain; S3, excavating a top drilling tunnel from the lower wall to the upper wall at the top of the middle section, excavating a roof plate along-vein grouting tunnel along the ore body in the upper wall, constructing a number of upper wall grouting holes parallel to the ore body inclination in the roof plate along-vein grouting tunnel, and forming a three-way upper wall curtain after grouting; S4. At the bottom of the middle section, a segmented rock drilling tunnel is excavated from the lower wall to the boundary of the ore body near the lower wall, and the bottom ore body is mined and filled or pre-grouted according to the economic indicators of ore body mining to form a four-way bottom plate curtain; the segmented rock drilling tunnel of each segment is excavated from the lower wall to the upper wall to mine different segments; S5. Repeat steps S2-S4 to mine the remaining middle section.

[0006] In the technical scheme of the embodiment of the present application, firstly, by reasonably arranging the order of ore body recovery, and making full use of the filling body formed by the previous recovery project as a one-way filling body curtain and a two-way filling body curtain, efficiency is improved and cost is saved; then, the curtain grouting technology is used to form a three-way upper plate curtain and a four-way bottom plate curtain at the upper plate and bottom plate of the ore body, so that a complete "four-way space curtain" is established in the upper plate, bottom plate, and two sides of the ore body in the water-hazard mining area, avoiding the influence of groundwater on the water-hazard mining area, and converting the water-hazard mining area into a water-free area; then, after the multi-directional space curtain is formed, a medium-deep hole process with large production capacity is adopted for mining, thereby realizing safe and efficient mining under complex sudden water conditions.

[0007] In some embodiments, in step S2, a safety zone without water gushing out is provided between the water-hazardous mining area and the first ordinary mining area and the second ordinary mining area; and the length of the safety zone is not less than 10 m.

[0008] In this embodiment, by setting up a safety zone, the impact of the water-damaged mining area on the mining process of the first ordinary mining area and the second ordinary mining area is reduced, and by reserving a safety distance, safe mining in the ordinary mining area is ensured.

[0009] In some embodiments, the unidirectional filling body curtain and the bidirectional filling body curtain are embedded in the upper plate, and the thickness of the unidirectional filling body curtain and the bidirectional filling body curtain embedded in the upper plate is ≥1 m.

[0010] In this embodiment, by setting the thickness of the one-way filling body curtain and the two-way filling body curtain to be greater than the thickness of the water-hazardous mining area, it is convenient to overlap with the three-way wall curtain subsequently formed in the upper wall, thereby further improving the water blocking effect.

[0011] In some embodiments, the strength of the filling body within 3 to 5 m of the one-way filling body curtain and the two-way filling body curtain close to the safety zone is ≥5 MPa.

[0012] In this embodiment, the water blocking effect is further improved by setting the filling body on one side of the first common mining area and the second common mining area adjacent to the water-hazardous mining area to a high-strength cemented filling body.

[0013] In some embodiments, the ore body is a medium-thick or thick ore body, and the ore body inclination angle is >30°.

[0014] In this embodiment, by reasonably setting the thickness and inclination of the ore body, the mining cost is reduced, and the smooth formation of the upper wall grouting holes and the three-way upper wall curtain is facilitated.

[0015] In some embodiments, in step S3, the length of the vein grouting tunnel is equal to the sum of the lengths of the water-hazard mining area and the safety areas on both sides; The upper plate grouting holes are arranged in 1 to 3 rows, and the upper plate grouting holes between adjacent rows are staggered; the row spacing of the upper plate grouting holes is less than 3m, and the hole spacing of each row is 3 to 5m; the length of the upper plate grouting holes is equal to the oblique length of the middle section; the upper plate grouting holes extend along the direction of the ore body to the safety zone, and the distance between the upper plate grouting holes at the end and the one-way filling body curtain and the two-way filling body curtain is less than 1m.

[0016] In this embodiment, by connecting the vein grouting tunnel to the one-way filling body curtain and the two-way filling body curtain on both sides, favorable conditions are provided for setting wider upper plate grouting holes and three-way upper plate curtains; by reasonably setting the row spacing of the upper plate grouting holes and the hole spacing of each row, the slurry in the adjacent upper plate grouting holes can overlap after the slurry penetrates along the rock cracks, forming a complete and thick three-way upper plate curtain, thereby improving the water-blocking effect.

[0017] In some embodiments, grouting uses ultrafine grouting materials with a water-cement mass ratio of 0.7-0.9:1, the initial setting time is ≤30min, and the final grouting pressure is 2-3 times the hydrostatic pressure; the 3-day compressive strength of the slurry of the three-upward plate curtain is ≥15MPa.

[0018] In this embodiment, by reasonably setting the water-cement mass ratio of grouting, a grouting material with good injectability is formed, thereby improving the water-isolating effect of the slurry.

[0019] In some embodiments, the middle section mining is specifically as follows: constructing an upward medium-deep hole in the segmented rock drilling tunnel in the middle section bottom segment, taking the three-upward plate curtain as the starting point, mining the ore in a backward manner, mining the remaining segments from bottom to top, and filling them afterwards.

[0020] In this embodiment, by adopting a medium-deep hole process with high production capacity to mine the water-hazard mining area, and utilizing the mutual coordination of the "four-way space curtain" and the medium-deep hole mining process, safe, efficient and green mining of difficult-to-mine mineral bodies under complex sudden water conditions in the upper plate can be achieved.

[0021] In some embodiments, in step S4, when the sales revenue of the ore body mining in the area of ​​the four-way bottom plate curtain to be formed is ≥ the mining cost, the "advance mining + subsequent filling" is adopted for the bottom ore body to form the four-way bottom plate curtain; when the sales revenue of the ore body mining is < the mining cost, only advance grouting is carried out on the bottom ore body to form the four-way bottom plate curtain.

[0022] In this embodiment, a suitable method is selected to form a four-way floor curtain according to the economic rationality of ore body mining, thereby reducing costs and improving economic benefits.

[0023] In some embodiments, in step S2, the location of the water body is detected by combining "geophysical exploration + drilling".

[0024] In this embodiment, the water-containing body is detected by combining "geophysical exploration + drilling" with high detection accuracy, which provides favorable conditions for the formation of the "four-way space curtain" and realizes efficient water blocking.

[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] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings used in the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 This is a schematic diagram of the recovery sequence in the embodiment of the present application; Figure 2 This is a schematic diagram of a multi-directional space curtain in an embodiment of the present application; Figure 3 This is a front view of a multi-directional space curtain medium-deep hole mining method under complex sudden water inrush conditions in the upper wall in an embodiment of the present application; Figure 4 for Figure 3 Schematic diagram of the II-II direction; Figure 5 for Figure 3 Schematic diagram of the III-III direction; Explanation of the reference numerals: 1-water-hazard mining area; 2-first ordinary mining area; 3-second ordinary mining area; 4-auxiliary ramp; 5-segmented horizontal tunnel; 6-one-way filling body curtain; 7-two-way filling body curtain; 8-top rock drilling tunnel; 9-top plate along-vein grouting tunnel; 10-upper plate grouting hole; 11-three-way upper plate curtain; 12-segmented rock drilling tunnel; 13-four-way bottom plate curtain; 14-safety area; 15-upper plate water-bearing area; 16-bottom plate grouting hole. DETAILED DESCRIPTION

[0028] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field 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" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0030] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0031] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "length", "width" and "thickness" is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the embodiments of the present application.

[0032] The coastal area is rich in gold geological resources, but the special geographical location of Binhai and the objective conditions of the existence of structural fissures make Binhai deep mines not only face the typical problems of deep mine recovery, but also suffer from major geological disasters such as underground sudden water inrush, resulting in slow mining and mining speed. Curtain grouting is a conventional means of isolating underground water inrush and controlling water hazards. The existing curtain grouting method cannot meet the effective mining of ore bodies with extremely complex hydrogeology.

[0033] In order to solve the technical problem that the existing curtain grouting method cannot meet the effective mining of ore bodies with extremely complex hydrogeology, the present application provides a multi-directional space curtain medium-deep hole mining method under complex sudden water inrush conditions in the upper plate, wherein, firstly, the order of ore body recovery is reasonably arranged, and the filling body formed by the previous recovery project is fully utilized as a one-way filling body curtain and a two-way filling body curtain, so as to improve efficiency and save costs; then, the curtain grouting technology is used to form a three-way upper plate curtain and a four-way bottom plate curtain at the upper plate and bottom plate position of the ore body, so that a complete "four-way space curtain" is established in the upper plate, bottom plate, and two sides of the ore body in the water-damaged mining area, avoiding the influence of groundwater on the water-damaged mining area and transforming the water-damaged mining area into a water-free area; then, after the multi-directional space curtain is formed, a medium-deep hole process with large production capacity is adopted for mining, thereby realizing safe and efficient mining under complex sudden water inrush conditions. This method is safe and reliable, with flexible technology. The hole layout plan can be adjusted at any time according to the ore body and water gushing conditions, which saves grouting costs to the greatest extent, improves ore mining rate, reduces loss and depletion rate, and increases resource utilization rate of mines. It is of great significance to the mining of mines threatened by water disasters.

[0034] Please refer to Figures 1 to 5 The present application provides a method for multi-directional space curtain deep hole mining under complex water inrush conditions in the upper plate, comprising the following steps: S1. Divide the ore body into middle sections along the vertical height, divide the middle sections into subsections, and mine from top to bottom using the middle sections as units, and excavate auxiliary ramps 4 in the lower wall to connect different middle sections and subsections. Specifically, Figure 2 The X axis is the ore body strike, the Y axis is the ore body thickness direction, and the Z axis is the vertical height direction. The auxiliary ramp 4 is set along the vertical height direction of the ore body. If conditions permit, multiple middle sections can also be mined at the same time.

[0035] In this step, the ore body is first divided into different middle-section mining units, and the middle section is further subdivided into sections. At the same time, an auxiliary ramp 4 is constructed to facilitate the smooth progress of the mining operation.

[0036] S2, such as Figure 1 As shown, the location of the water-bearing body in the ore body is detected, and the middle section is divided along the direction of the ore body into a water-damaged mining area 1 and a first common mining area 2 and a second common mining area 3 located on both sides of the water-damaged mining area 1; after the segmented horizontal tunnel 5 along the direction of the ore body is excavated in the lower plate to form the mining conditions, the first common mining area 2 and the second common mining area 3 are mined and filled to form a one-way filling curtain 6 and a two-way filling curtain 7. Specifically, the location of the water-bearing body in the middle section is detected separately during the actual production process, or the location of the water-bearing body in the entire ore body is directly detected. When mining the first common mining area 2 and the second common mining area 3, medium-deep hole blasting is used to advance from both ends to the water-damaged mining area 1, and the filling mining method can be used.

[0037] In this step, before mining the sections, firstly, the locations of the water-bearing bodies of the sections are detected, and the conditions of the ore bodies of the sections are understood, so as to provide favorable conditions for efficient and safe mining of the sections; then, the middle section is divided into a water-hazard mining area 1 and a first common mining area 2 and a second common mining area 3 on both sides along the direction of the ore body; first, the first common mining area 2 and the second common mining area 3 which are safe and have a simple ore body environment are mined; and then, filling is performed after mining; in the process of mining the ore body, the filling body formed by filling the goaf is used as a water-blocking curtain (i.e., a one-way filling body curtain 6 and a two-way filling body curtain 7) on both sides of the water-hazard mining area 1, and the engineering of the first common mining area 2 and the second common mining area 3 is fully utilized to form a space curtain without the need for additional curtain grouting, which not only reduces the workload of grouting, improves efficiency and saves costs, but also has good density and thickness of the filling body and good water-blocking effect.

[0038] S3. At the top of the middle section, a top drilling tunnel 8 is excavated from the lower plate to the upper plate, and a top plate along-vein grouting tunnel 9 is excavated along the direction of the ore body in the upper plate. Several upper plate grouting holes 10 parallel to the inclination of the ore body are constructed in the top plate along-vein grouting tunnel 9, and a three-way upper plate curtain 11 is formed after grouting. Specifically, the top drilling tunnel 8 is arranged along the thickness direction of the ore body, the along-vein grouting tunnel 9 is arranged along the direction of the ore body, and the upper plate grouting holes 10 are arranged in the upper plate. It can be understood that if it is found after detection that the upper plate water-bearing area 15 extends into the ore body and affects the recovery of part of the ore body, at this time, the upper plate grouting holes 10 are located in the ore body, separating the water-gushing area and the non-water-gushing area of ​​the ore body. Adopting the cycle mode of "advance grouting + blasting excavation + advance grouting", one or more top rock drilling tunnels 8 are excavated at the top of the middle section of the ore body to prevent water inrush from occurring in the top rock drilling tunnel 8 during the excavation process toward the upper plate water-bearing area 15; continuing to adopt the cycle mode of "advance grouting + blasting excavation + advance grouting" to excavate the top plate vein grouting tunnel 9 along the direction of the ore body to form an upper plate grouting curtain operation space; the upper plate grouting holes 10 are distributed throughout the entire upper plate area of ​​the water-hazard mining area 1 and the safety area 14.

[0039] In this step, by excavating the top rock drilling tunnel 8 and the vein grouting tunnel 9, a working space is provided for the subsequent upper wall grouting hole 10, thereby forming a three-upward wall curtain 11. The upper wall grouting hole 1 is set parallel to the inclination of the ore body, so that the formed three-upward wall curtain 11 is close to the water-damaged mining area 1, which is convenient for better water blocking.

[0040] S4. At the bottom of the middle section, a segmented drilling tunnel 12 is excavated from the lower plate to the boundary of the ore body near the lower plate. The bottom ore body is mined and backfilled or pre-grouted according to the economic and reasonable conditions of ore body mining to form a four-way bottom plate curtain 13; segmented drilling tunnels 12 of each segment are excavated from the lower plate to connect various mining areas, and different segments are mined by using the method of medium-deep hole mining + subsequent backfilling, and the mine room is arranged perpendicular to the direction of the ore body. Specifically, a cyclic excavation method of "advance grouting + blasting excavation + advance grouting" is adopted, and a segmented rock drilling tunnel 12 is excavated from the lower plate at the bottom of the middle section to the boundary of the ore body near the lower plate. When the economic and technical indicators of ore body mining in the area of ​​the four-way bottom plate curtain 13 to be formed are reasonable (i.e., sales revenue ≥ mining cost), the segmented rock drilling tunnel 12 is continued to be extended to the upper plate of the ore body, and the "advance mining + subsequent filling" is adopted for the bottom ore body to form the four-way bottom plate curtain 13, and the method of forming the four-way bottom plate curtain 13 is economically reasonable; when the economic and technical indicators of ore body mining are unreasonable (i.e., sales revenue < mining cost), no mining is carried out, and bottom plate grouting holes 16 are directly constructed in the ore body in the segmented horizontal tunnel 5 perpendicular to the upper plate direction, and advance grouting is carried out on the ore body in the curtain area to form, and the four-way bottom plate curtain 13 is formed after grouting. The spacing between the bottom plate grouting holes 16 is 3-5m, so that the grout in the adjacent bottom plate grouting holes 16 can overlap after the grout penetrates along the rock mass fissures, forming a complete four-way bottom plate curtain 13. The thickness of the four-way bottom plate curtain 13 is ≥4m, which prevents water from seeping into the middle section mining area from the bottom of the middle section. After the four-way bottom plate curtain 13 is formed, a segmented rock drilling tunnel 12 is constructed on the upper surface of the four-way bottom plate curtain 13 from the lower plate to the upper plate to carry out the mining work of the lowest segment.

[0041] In this step, the segmented rock drilling tunnel 12 is excavated to provide working space for the four-way bottom plate curtain 13 and subsequent medium-deep hole mining. Through the mutual coordination of the one-way filling body curtain 6, the two-way filling body curtain 7 and the three-way upper plate curtain 11, the ore body in the water-hazard mining area 1 is transformed into an ordinary mining area ore body without water hazard threat, and then the medium-deep hole mining is realized by excavating each segmented mining project. In addition, before the mining of this middle section, the ore body at the corresponding position of the previous middle section in the vertical direction has usually completed the mining and filling operations. At this time, the filling body of the previous middle section can be used as the five-way roof curtain of this middle section, further improving the safety of the water-hazard mining area 1; at the same time, the four-way bottom plate curtain 13 of this middle section can also be used as the five-way roof curtain of the next middle section, greatly reducing the grouting cost.

[0042] S5. Repeat steps S2-S4 to mine the remaining middle section until the mining of the entire ore body is completed.

[0043] In the technical solution of the embodiment of the present application, firstly, the order of ore body recovery is reasonably arranged, the first common mining area 2 and the second common mining area 3 are recovered, and the filling body formed by the previous recovery project is fully utilized as the one-way filling body curtain 6 and the two-way filling body curtain 7, so as to improve efficiency, save costs, and have a good water blocking effect; then, the auxiliary ramp 4, the segmented horizontal tunnel 5, the top rock drilling tunnel 8, the vein grouting tunnel 9 and the segmented rock drilling tunnel 12 and other development projects are used to connect the middle section to be recovered, and three-way filling curtains are formed at the upper plate and the bottom plate of the ore body respectively. The upper plate curtain 11 and the four-way bottom plate curtain 13 enable a complete "four-way space curtain" to be set up in the upper plate, bottom plate, and two sides of the ore body in the water-hazard mining area 1, isolating the possible water gushing points around the water-hazard mining area 1, avoiding the influence of groundwater on the water-hazard mining area 1, and making the water-hazard mining area 1 a water-free area; after the multi-directional space curtain is formed, the segmented rock drilling tunnel 12 of each segment of the water-hazard mining area 1 is excavated from the lower plate to the upper plate to carry out medium-deep hole mining of the ore body, thereby realizing safe and efficient mining under complex sudden water gushing conditions. This method is safe and reliable, with flexible process. The hole layout plan can be adjusted at any time according to the ore body and water gushing conditions, saving grouting costs to the greatest extent, improving the ore mining rate, reducing the loss and depletion rate, and increasing the resource utilization rate of the mine.

[0044] Furthermore, in some embodiments, Figure 1 As shown, in step S2, a safety zone 14 without water inrush is provided between the water-hazard mining area 1 and the first common mining area 2 and the second common mining area 3, and the length of the safety zone 14 is not less than 10 m.

[0045] In the technical solution of the embodiment of the present application, a safety redundant length, namely a safety zone 14, is set between the water-hazard mining area 1 and the first ordinary mining area 2 and the second ordinary mining area 3 to reduce the impact of the water-hazard mining area 1 on the mining process of the first ordinary mining area 2 and the second ordinary mining area 3, thereby ensuring the safe and efficient mining of the first ordinary mining area 2 and the second ordinary mining area 3; at the same time, the width of the subsequent three-way wall curtain 11 and the four-way bottom plate curtain 13 (i.e., the length along the direction of the ore body) is expanded to ensure to the greatest extent that the formed "four-way space curtain" can achieve efficient water blocking in the water-hazard mining area 1.

[0046] Further, in some embodiments, as shown in Figure 1, the one-way filling body curtain 6 and the two-way filling body curtain 7 are embedded in the upper plate, that is, the thickness of the one-way filling body curtain 6 and the two-way filling body curtain 7 is greater than the thickness of the water-hazard mining area 1, and the thickness of the one-way filling body curtain 6 and the two-way filling body curtain 7 embedded in the upper plate is ≥1m. Specifically, during the mining and filling process of the first ordinary mining area 2 and the second ordinary mining area 3, a certain thickness is mined and filled more toward the upper plate.

[0047] In the technical solution of the embodiment of the present application, by setting the thickness of the one-way filling body curtain 6 and the two-way filling body curtain 7 to be greater than the thickness of the water-hazardous mining area 1, and embedding the one-way filling body curtain 6 and the two-way filling body curtain 7 in the upper plate, it is convenient to overlap with the three-way plate curtain 11 subsequently formed in the upper plate, thereby further improving the water-blocking effect.

[0048] Furthermore, in some embodiments, the strength of the filling body within 3 to 5 m of the one-way filling body curtain 6 and the two-way filling body curtain 7 close to the safety zone 14 is ≥5 MPa.

[0049] In the technical solution of the embodiment of the present application, by setting the filling body on one side of the first ordinary mining area 2 and the second ordinary mining area 3 adjacent to the water-hazardous mining area 1 as a high-strength cemented filling body, the strength of the one-way filling body curtain 6 and the two-way filling body curtain 7 close to the upper plate water-bearing area 15 is better, thereby further improving the water-blocking effect.

[0050] Furthermore, in some embodiments, the ore body is a medium-thick or thick ore body, and the ore body inclination is >30°.

[0051] In the technical solution of the embodiment of the present application, by setting the ore body to a medium-thick or thick ore body, after forming the "four-way space curtain", the amount of ore recovered is large, thereby achieving the effect of reducing costs. By setting the ore body inclination angle to >30°, the inclination of the ore body is relatively large, which facilitates the smooth formation of the upper wall grouting hole 10 and the three-way upper wall curtain 11.

[0052] Further, in some embodiments, in step S3, the length of the vein grouting tunnel 9 is equal to the sum of the lengths of the water-hazard mining area 1 and the safety areas 14 on both sides, that is, the vein grouting tunnel 9 connects the one-way filling body curtain 6 and the two-way filling body curtain 7; There are 1 to 3 rows of grouting holes 10 in the upper plate, and the upper plate grouting holes 10 in adjacent rows are staggered; the row spacing of the grouting holes 10 in the upper plate is <3m, and the hole spacing of each row is 3 to 5m; the length of the grouting holes 10 in the upper plate is equal to the oblique length of the middle section; the grouting holes 10 in the upper plate extend along the direction of the ore body to the safe zone 14, and the distance between the upper plate grouting holes 10 at the end and the one-way filling body curtain 6 and the two-way filling body curtain 7 is <1m; specifically, the number of rows of the grouting holes 10 in the upper plate depends on the water gushing amount of the upper plate. When the water gushing amount of the upper plate is large, the number of rows of the grouting holes 10 in the upper plate is large.

[0053] In the technical solution of the embodiment of the present application, by setting the length of the grouting tunnel 9 along the vein to be equal to the sum of the lengths of the water-hazardous mining area 1 and the safety areas 14 on both sides, the grouting tunnel 9 along the vein is connected to the one-way filling body curtain 6 and the two-way filling body curtain 7 on both sides, providing favorable conditions for setting a wider upper plate grouting hole 10 and a three-way upper plate curtain 11. The number of rows of the upper plate grouting holes 10 is set according to the water inflow of the upper plate to ensure that the three-way upper plate curtain 11 formed is thicker, thereby improving the water blocking effect. By staggering the upper plate grouting holes 10 between adjacent rows, and by reasonably setting the row spacing of the upper plate grouting holes 10 and the hole spacing of each row, the slurry in the adjacent upper plate grouting holes 10 can be overlapped after the slurry penetrates along the rock mass fissures, forming a complete and thick three-way upper plate curtain 11, thereby improving the water blocking effect. By reasonably setting the distance between the upper plate grouting hole 10 at the end and the one-way filling body curtain 6 and the two-way filling body curtain 7, the slurry can better overlap with the one-way filling body curtain 6 and the two-way filling body curtain 7 on both sides after penetrating along the rock cracks, so that the three-way upper plate curtain 11 can be better overlapped with the one-way filling body curtain 6 and the two-way filling body curtain 7 to form a whole.

[0054] Furthermore, in some embodiments, the grouting uses ultrafine grouting materials with a water-cement mass ratio of 0.7-0.9:1, the initial setting time is ≤30min, the final grouting pressure is 2-3 times the hydrostatic pressure, and the 3-day compressive strength of the slurry of the three-upward plate curtain 11 is ≥15MPa. Specifically, the water-cement mass ratio of the grouting is preferably 0.8:1.

[0055] In the technical solution of the embodiment of the present application, by reasonably setting the water-cement mass ratio of grouting, a grouting material with good injectability is formed, thereby improving the water-blocking effect of the slurry. By reasonably controlling the initial setting time of the slurry after grouting, the final grouting pressure, and the compressive strength of the slurry after 3 days, a hard, high water-blocking three-way wall curtain 11 is formed after the slurry solidifies.

[0056] Further, in some embodiments, the middle section mining is specifically as follows: constructing an upward medium-deep hole in the segmented rock drilling tunnel 12 of the middle section bottom section, taking the three-way upward plate curtain 11 as the starting point, mining the ore in a backward manner, mining the remaining sections from bottom to top, and then filling until the mining of the entire middle section is completed. Specifically, the height of the segmented rock drilling tunnel 12 is 4.2m, which is adapted to the medium-deep hole mining process requirements. In the vertical height direction, the bottom of the segmented rock drilling tunnel 12 is close to the top of the four-way bottom plate curtain 13 for excavation construction.

[0057] In the technical solution of the embodiment of the present application, on the basis of forming a highly water-resistant "four-way space curtain", the water-hazard mining area 1 is transformed into an ordinary safe mining area, and then the water-hazard mining area 1 is mined by adopting a medium-deep hole process with high production capacity. Through the mutual coordination of the "four-way space curtain" and the medium-deep hole mining process, the safe, efficient and green mining of difficult-to-mine mineral bodies under complex sudden water conditions in the upper plate is achieved, the ore mining rate is improved, and the loss and depletion rate is reduced, which is of great significance to mines threatened by water disasters.

[0058] Furthermore, in some embodiments, in step S4, when the economic and technical indicators of ore body mining in the area of ​​the proposed four-way bottom plate curtain 13 are reasonable (i.e., sales revenue ≥ mining cost), "advance mining + subsequent filling" is adopted for the bottom ore body to form the four-way bottom plate curtain 13; when the economic and technical indicators of ore body mining are unreasonable (i.e., sales revenue < mining cost), only advance grouting is carried out on the bottom ore body to form the four-way bottom plate curtain 13.

[0059] In the technical solution of the embodiment of the present application, a suitable method is selected according to the economic and reasonable conditions of ore body mining to form the four-way bottom plate curtain 13, so as to reduce costs and improve economic benefits.

[0060] Furthermore, in some embodiments, in step S2, the location of the water-bearing body is detected by combining "geophysical exploration + drilling" and marked as the water-damaged mining area 1 that may be threatened by water damage. Specifically, after the middle section development project is completed, the geophysical exploration equipment is used to roughly delineate the scope of the entire middle section water-bearing body to ensure the safety of normal excavation operations of the mining project. When approaching the water-bearing body impact area, detailed water exploration work is performed again before each excavation by combining geophysical exploration + drilling until the scope of the final water-damaged mining area 1 is determined.

[0061] In the technical solution of the embodiment of the present application, the water-containing body is detected by combining "geophysical exploration + drilling" with high detection accuracy, which provides favorable conditions for the formation of the "four-way space curtain" and realizes efficient water blocking, thereby transforming the water-damaged mining area 1 into a safe mining area.

[0062] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are only examples, and the embodiments having the same structure as the technical idea and exerting the same effect within the scope of the technical solution of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the main purpose of the present application, various modifications that can be thought of by those skilled in the art to the embodiments and other methods of combining some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate, characterized in that: The following steps are involved: S1. Divide the ore body into middle sections along the vertical height, and then divide the middle sections into subsections. Mining is carried out from top to bottom with the middle sections as units, and auxiliary ramps are excavated in the footwall to connect different middle sections and subsections. S2, detecting the location of the water-bearing body in the ore body, dividing the middle section along the ore body strike into a water-damaged mining area and a first common mining area and a second common mining area located on both sides of the water-damaged mining area; excavating a segmented horizontal tunnel along the ore body strike in the lower wall, mining and filling the first common mining area and the second common mining area, forming a one-way filling curtain and a two-way filling curtain; S3, excavating a top rock drilling tunnel from the lower wall to the upper wall at the top of the middle section, excavating a roof plate along the vein grouting tunnel along the ore body in the upper wall, constructing a number of upper wall grouting holes parallel to the inclination of the ore body in the roof plate along the vein grouting tunnel, and forming a three-way upper wall curtain after grouting; S4. At the bottom of the middle section, a segmented rock drilling tunnel is excavated from the lower wall to the boundary of the ore body near the lower wall, and the bottom ore body is mined and filled or pre-grouted according to the economic indicators of ore body mining to form a four-way bottom plate curtain; the segmented rock drilling tunnel of each segment is excavated from the lower wall to the upper wall to mine different segments; S5. Repeat steps S2-S4 to mine the remaining middle section.

2. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 1 is characterized in that: In step S2, a safety zone without water gushing out is provided between the water-hazard mining area and the first common mining area and the second common mining area; and the length of the safety zone is not less than 10 m.

3. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 2 is characterized in that: The one-way filling body curtain and the two-way filling body curtain are embedded in the upper plate, and the thickness of the one-way filling body curtain and the two-way filling body curtain embedded in the upper plate is ≥1m.

4. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 3 is characterized in that: The strength of the filling body within 3 to 5 m of the one-way filling body curtain and the two-way filling body curtain close to the safety zone is ≥5 MPa.

5. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 4 is characterized in that: The ore body is a medium-thick or thick ore body, and the ore body inclination is >30°.

6. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 5 is characterized in that: In step S3, the length of the grouting tunnel along the vein is equal to the sum of the lengths of the water-hazard mining area and the safety areas on both sides; The upper plate grouting holes are arranged in 1 to 3 rows, and the upper plate grouting holes between adjacent rows are staggered; the row spacing of the upper plate grouting holes is less than 3m, and the hole spacing of each row is 3 to 5m; the length of the upper plate grouting holes is equal to the oblique length of the middle section; the upper plate grouting holes extend along the direction of the ore body to the safety zone, and the distance between the upper plate grouting holes at the end and the one-way filling body curtain and the two-way filling body curtain is less than 1m.

7. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 6 is characterized in that: The grouting uses ultra-fine grouting materials with a water-cement mass ratio of 0.7-0.9:1, the initial setting time is ≤30min, and the final grouting pressure is 2~3 times the hydrostatic pressure; the 3-day compressive strength of the slurry of the three-upward plate curtain is ≥15MPa.

8. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 7 is characterized in that: The specific method of middle section mining is as follows: construct an upward medium-deep hole in the segmented rock drilling tunnel in the middle section bottom segment, use the three-upward plate curtain as the starting point, mine the ore in a backward manner, mine the remaining segments from bottom to top, and then fill them.

9. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 1 is characterized in that: In step S4, when the sales revenue of the ore body mining in the area of ​​the four-way floor curtain to be formed is greater than or equal to the mining cost, the bottom ore body is subjected to "advance mining + subsequent filling" to form the four-way floor curtain; when the sales revenue of the ore body mining is less than the mining cost, only advance grouting is performed on the bottom ore body to form the four-way floor curtain.

10. The multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper plate according to claim 1, characterized in that: In step S2, the location of the water body is detected by combining "geophysical exploration + drilling".

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