Multi-directional spatial curtain medium-deep hole mining method under the complex water inrush conditions of the hanging wall

Abstract

The present application provides a multi-directional space curtain medium-deep hole mining method under the condition of complex water inrush from the hanging wall, belonging to the field of underground mine mining. Among them, the multi-directional space curtain medium-deep hole mining method under the condition of complex water inrush from the hanging wall includes the following steps: dividing the ore body, detecting the position of the water-bearing body in the ore body, mining and backfilling the ordinary mining areas on both sides of the water hazard mining area, forming a three-way hanging wall curtain and a four-way floor curtain by curtain grouting on the hanging wall and the floor of the water hazard mining area, and mining the water hazard mining area. After the multi-directional space curtain is formed in the present application, a medium-deep hole process with a large production capacity is used for mining, thereby realizing safe and high-efficiency mining under the condition of complex water inrush. The mining method is safe and reliable, and the process is flexible. The hole layout plan can be adjusted at any time according to the ore body and water inrush conditions, saving the grouting cost to the greatest extent, improving the ore mining rate, reducing the loss and dilution rate, increasing the resource utilization rate of the mine, and having great significance for mines threatened by water hazards.

Description

Technical Field

[0001] The present invention relates to the technical field of underground mine mining, and particularly relates to a multi-directional space curtain medium-deep hole mining method under the condition of complex water inrush from the hanging wall. Background Art

[0002] Curtain grouting is a conventional means to isolate underground water inrush and control water disasters. At present, curtain grouting mainly has several forms such as "constructing an L-shaped grouting cut-off curtain", "water conservation mining method of sectional grouting curtain in aquifers", and "three-way advanced curtain grouting method for mining headings". Although it has certain guiding significance for water inrush control, its common problem is that the water inrush situation faced is simple, the number of water outlets is small, the curtain can be constructed in the form of a "single plane", and the occurrence conditions of the ore body are good, and the ore body can be mined without complex mining processes. When there is a water-conducting fault zone connecting with seawater in the hanging wall of the ore body and the hydrogeology is extremely complex, water inrush points may exist on the roof and floor, both sides, and the heading face of the exposed working space. The existing curtain can no longer meet the production and safety needs, and the ore body mining is threatened by water disasters at all times, and the roadway driving is difficult. Summary of the Invention

[0003] In view of the technical problems in the background art, the present application provides a multi-directional space curtain medium-deep hole mining method under the condition of complex water inrush from the hanging wall, aiming to solve the technical problem that the existing curtain grouting method cannot meet the effective mining of ore bodies with extremely complex hydrogeology.

[0004] The embodiment of the present application provides a multi-directional space curtain medium-deep hole mining method under the condition of complex water inrush from the hanging wall, including the following steps:

[0005] S1. Divide the ore body into levels along the vertical height, divide each level into sections, and conduct back mining from top to bottom with each level as a unit. Drive an auxiliary ramp in the footwall to connect different levels and sections;

[0006] S2. Detect the position of the water-bearing body in the ore body, divide the level along the strike of the ore body into a water disaster mining area and a first ordinary mining area and a second ordinary mining area on both sides of the water disaster mining area; drive sectional headings along the strike of the ore body in the footwall, and conduct back mining and filling of the first ordinary mining area and the second ordinary mining area to form a one-way filling body curtain and a two-way filling body curtain;

[0007] S3. Drive a top rock-drilling roadway from the footwall to the hanging wall at the top of the level, drive a roof drift along the strike of the ore body on the hanging wall, construct a number of upper wall grouting holes parallel to the dip angle of the ore body in the roof drift, and form a three-way upper wall curtain after grouting;

[0008] S4. Drive a sectional drilling roadway from the footwall at the bottom of the middle section to the boundary of the ore body near the footwall, and backfill or pre-grout the bottom ore body according to the mining economic indicators of the ore body to form a four-way floor curtain; drive the sectional drilling roadway of each section from the footwall to the hanging wall and backfill different sections.

[0009] S5. Repeat steps S2 - S4 to backfill the remaining middle sections.

[0010] In the technical solution of the embodiment of the present application, firstly, by reasonably arranging the ore body mining sequence and making full use of the filling bodies formed by the previous mining projects as the one-way filling body curtain and the two-way filling body curtain, the efficiency is improved and the cost is saved; then, the curtain grouting technology is used to form a three-way hanging wall curtain and a four-way floor curtain at the hanging wall and floor positions of the ore body, so as to establish a complete "four-way space curtain" in the four directions of the hanging wall, floor, and two sides of the ore body in the water disaster mining area, avoiding the influence of groundwater on the water disaster mining area and converting the water disaster mining area into a water-free area; then, after the multi-way space curtain is formed, the medium-deep hole technology with a large production capacity is used for mining, thereby realizing safe and high-efficiency mining under complex water inrush conditions.

[0011] In some embodiments, in step S2, a water-free safety area is provided between the water disaster mining area and the first ordinary mining area and the second ordinary mining area; the length of the safety area is not less than 10 m.

[0012] In this embodiment, by setting the safety area, the influence of the water disaster 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, the safe mining of the ordinary mining area is ensured.

[0013] In some embodiments, the one-way filling body curtain and the two-way filling body curtain are embedded in the hanging wall, and the thickness of the one-way filling body curtain and the two-way filling body curtain embedded in the hanging wall is ≥1 m.

[0014] 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 disaster mining area, it is convenient to overlap with the three-way hanging wall curtain formed subsequently in the hanging wall, further improving the water blocking effect.

[0015] In some embodiments, the strength of the filling body within 3 - 5 m on the side of the one-way filling body curtain and the two-way filling body curtain close to the safety area is ≥5 MPa.

[0016] In this embodiment, by setting the filling body on the side of the first ordinary mining area and the second ordinary mining area adjacent to the water disaster mining area as a high-strength cemented filling body, the water blocking effect is further improved.

[0017] In some embodiments, the ore body is a medium-thick or thick and large ore body, and the dip angle of the ore body is > 30°.

[0018] In this embodiment, by reasonably setting the thickness and dip angle of the ore body, the mining cost is reduced, which is convenient for the smooth formation of the up-dip grouting holes and the three-way up-dip curtain.

[0019] In some embodiments, in step S3, the length of the roof drift along the vein is equal to the sum of the lengths of the water hazard mining area and the two adjacent safety areas on both sides;

[0020] The up-dip grouting holes are arranged in 1 to 3 rows, and the up-dip grouting holes in adjacent rows are arranged staggeredly; the row spacing between the up-dip grouting holes is < 3 m, and the hole spacing in each row is 3 to 5 m; the length of the up-dip grouting holes is equal to the inclined length of the level; the up-dip grouting holes extend along the strike of the ore body into the safety area, and the distance between the end up-dip grouting holes and the one-way filling body curtain and the two-way filling body curtain is < 1 m.

[0021] In this embodiment, by connecting the roof drift along the vein to the one-way filling body curtain and the two-way filling body curtain on both sides, it provides favorable conditions for setting wider up-dip grouting holes and the three-way up-dip curtain; by reasonably setting the row spacing and the hole spacing in each row of the up-dip grouting holes, the slurry in adjacent up-dip grouting holes can overlap after permeating along the rock fissures, forming a complete and thick three-way up-dip curtain, improving the water blocking effect.

[0022] In some embodiments, the grouting uses an ultra-fine grouting material with a water-cement mass ratio of 0.7 - 0.9:1, the initial setting time ≤ 30 min, and the final grouting pressure is 2 to 3 times the hydrostatic pressure; the 3-day compressive strength of the slurry of the three-way up-dip curtain is ≥ 15 MPa.

[0023] In this embodiment, by reasonably setting the water-cement mass ratio of the grouting, a grouting material with good injectability is formed, improving the water isolation effect of the slurry.

[0024] In some embodiments, the level mining is specifically as follows: upward medium-deep holes are drilled in the sublevel drift at the bottom of the level, starting from the three-way up-dip curtain, retreating mining and caving, and mining the remaining sublevels from bottom to top, followed by filling.

[0025] In this embodiment, by mining the water hazard mining area using the medium-deep hole technology with a large production capacity and utilizing the mutual cooperation of the "four-way space curtain" and the medium-deep hole mining technology, the safe, efficient and green mining of the difficult-to-mine ore body under the complex water inrush conditions of the up-dip is realized.

[0026] In some embodiments, in step S4, when the sales revenue from the ore body mining within the planned four-way floor curtain area ≥ the mining cost, the "drift mining + subsequent backfilling" method is adopted for the bottom ore body to form the four-way floor curtain; when the sales revenue from the ore body mining < the mining cost, only advanced grouting is carried out on the bottom ore body to form the four-way floor curtain.

[0027] In this embodiment, a suitable method is selected to form the four-way floor curtain according to the economic rationality of ore body mining, which reduces costs and improves economic benefits.

[0028] In some embodiments, in step S2, a combination of "geophysical exploration + drilling" is used to detect the location of the water-bearing body.

[0029] In this embodiment, the water-bearing body is detected by a combination of "geophysical exploration + drilling", with high detection accuracy, providing favorable conditions for the formation of the "four-way space curtain" and achieving efficient water blocking.

[0030] The above description is only an overview of the technical solution of this application. In order to be able to understand the technical means of this application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of this application more obvious and understandable, the specific embodiments of this application are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solution of this application, the drawings used in this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is a schematic diagram of the stoping sequence in the embodiment of this application;

[0033] Figure 2 It is a schematic diagram of the multi-way space curtain in the embodiment of this application;

[0034] Figure 3 It is the front view of the medium-deep hole mining method for the multi-way space curtain with complex water inrush conditions in the hanging wall in the embodiment of this application;

[0035] Figure 4 For Figure 3 the schematic diagram in the direction of II-II;

[0036] Figure 5 For Figure 3 the schematic diagram in the direction of III-III;

[0037] Description of the drawing reference numerals: 1 - Water hazard mining area; 2 - First general mining area; 3 - Second general mining area; 4 - Auxiliary ramp; 5 - Sublevel drift; 6 - One-way filling body curtain; 7 - Two-way filling body curtain; 8 - Top rock drilling roadway; 9 - Roof drift along strike for grouting; 10 - Hanging wall grouting hole; 11 - Three-way hanging wall curtain; 12 - Sublevel rock drilling roadway; 13 - Four-way floor curtain; 14 - Safety area; 15 - Hanging wall water-bearing area; 16 - Floor grouting hole. Detailed implementation manners

[0038] The embodiments of the technical solution of the present application will be described in detail below with reference to the drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill 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" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0040] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0041] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "length", "width", "thickness", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of this application.

[0042] To solve the technical problem that the existing curtain grouting method cannot meet the effective mining of ore bodies with extremely complex hydrogeological conditions, the present application provides a multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper wall. Firstly, by reasonably arranging the ore body mining sequence and making full use of the filling bodies formed by the previous mining projects as the first-direction filling body curtain and the second-direction filling body curtain, the efficiency is improved and the cost is saved. Then, the curtain grouting technology is used to form the third-direction upper wall curtain and the fourth-direction floor curtain at the upper wall and the floor positions of the ore body, so as to establish a complete "four-directional space curtain" in the four directions of the upper wall, the floor, and the two sides of the ore body in the water disaster mining area, avoiding the influence of groundwater on the water disaster mining area and transforming the water disaster mining area into a water-free area. After the multi-directional space curtain is formed, the medium-deep hole process with a large production capacity is adopted for mining, thereby realizing safe and high-efficiency mining under complex water inrush conditions. This method is safe and reliable, and the drilling layout plan can be adjusted at any time according to the ore body and water inrush conditions, saving the grouting cost to the greatest extent, improving the ore mining rate, reducing the loss and dilution rate, increasing the resource utilization rate of the mine, and being of great significance to the mining of mines threatened by water disasters.

[0043] Please refer to Figures 1 to 5 , the embodiment of the present application provides a multi-directional space curtain medium-deep hole mining method under complex water inrush conditions in the upper wall, including the following steps:

[0044] S1. Divide the ore body into levels along the vertical height, divide each level into sublevels, and mine from top to bottom with each level as a unit. Drive an auxiliary ramp 4 in the lower wall to connect different levels and sublevels. Specifically, Figure 2 the X-axis is the strike direction of the ore body, the Y-axis is the thickness direction of the ore body, and the Z-axis is the vertical height direction. The auxiliary ramp 4 is arranged along the vertical height direction of the ore body. If conditions permit, multiple levels can also be mined simultaneously.

[0045] In this step, the ore body is first divided into different level mining units, each level is further subdivided into sublevels, and the auxiliary ramp 4 is constructed simultaneously to facilitate the smooth progress of the mining operation.

[0046] S2. As Figure 1 shown, detect the position of the water-bearing body in the ore body, divide the level along the strike direction of the ore body into a water disaster mining area 1 and a first ordinary mining area 2 and a second ordinary mining area 3 on both sides of the water disaster mining area 1; drive a sublevel drift 5 along the strike direction of the ore body in the lower wall. After the mining conditions are formed, mine and fill the first ordinary mining area 2 and the second ordinary mining area 3 to form a first-direction filling body curtain 6 and a second-direction filling body curtain 7. Specifically, in the actual production process, detect the position of the water-bearing body in each level respectively, or directly detect the position of the water-bearing body in the whole ore body. When mining the first ordinary mining area 2 and the second ordinary mining area 3, use medium-deep hole blasting to advance from both ends to the water disaster mining area 1, and the filling mining method can be adopted.

[0047] In this step, before the sublevel stoping, the water-bearing body position of the sublevel is first detected to master the ore body situation of the sublevel, providing favorable conditions for the efficient and safe sublevel stoping. Then, the middle level is divided along the ore body strike into a water hazard mining area 1 and the first general mining area 2 and the second general mining area 3 on both sides. First, the first general mining area 2 and the second general mining area 3 with safe and simple ore body environment are mined, and after mining, backfilling is carried out. During the process of mining the ore body, the filling body formed by backfilling the mined-out area is used as a water-blocking curtain on both sides of the water hazard mining area 1 (i.e., the one-way filling body curtain 6 and the two-way filling body curtain 7). By making full use of the engineering-formed space curtain in the first general mining area 2 and the second general mining area 3, no additional curtain grouting is required, which not only reduces the grouting workload, improves efficiency and saves costs, but also has good compactness and large thickness of the filling body, and good water-blocking effect.

[0048] S3. From the footwall, a top rock-drilling roadway 8 is driven to the hanging wall at the top of the middle level, and a roof drift grouting roadway 9 is driven along the ore body strike on the hanging wall. A number of upper wall grouting holes 10 parallel to the dip angle of the ore body are constructed in the roof drift grouting roadway 9, and a three-way upper wall curtain 11 is formed after grouting. Specifically, the top rock-drilling roadway 8 is arranged along the thickness direction of the ore body, the roof drift grouting roadway 9 is arranged along the ore body strike, and the upper wall grouting holes 10 are arranged in the upper wall. It can be understood that if it is found after detection that the water-bearing area 15 in the upper wall extends into the ore body and affects the stoping of part of the ore body, at this time, the upper wall grouting holes 10 are located in the ore body, separating the water-inflow area and the non-water-inflow area of the ore body. Adopting a cycle mode of "advance grouting + blasting excavation + advance grouting", one or more top rock-drilling roadways 8 are driven at the top of the ore body middle level to prevent water inrush during the process of driving the top rock-drilling roadway 8 towards the water-bearing area 15 in the hanging wall; continue to adopt the cycle excavation mode of "advance grouting + blasting excavation + advance grouting" to drive the roof drift grouting roadway 9 along the ore body strike to form an operation space for the upper wall grouting curtain; the upper wall grouting holes 10 cover the entire upper wall area of the water hazard mining area 1 and the safety area 14.

[0049] In this step, by driving the top rock-drilling roadway 8 and the roof drift grouting roadway 9, a working space is provided for the subsequent upper wall grouting holes 10, and then a three-way upper wall curtain 11 is formed. The upper wall grouting holes 1 are set parallel to the dip angle of the ore body, so that the formed three-way upper wall curtain 11 is closely attached to the water hazard mining area 1, which is convenient for better water blocking.

[0050] S4. Drive the sectional drilling roadway 12 from the footwall at the bottom of the middle section to the boundary of the ore body near the footwall. According to the economic rationality of ore body mining, extract and backfill the bottom ore body or conduct advance grouting, and form a four-way floor curtain 13. Drive the sectional drilling roadway 12 of each section from the footwall to connect each stope, and use medium-deep hole caving + subsequent filling method to extract different sections. The ore room is arranged perpendicular to the ore body strike. Specifically, adopt a cyclic driving method of "advance grouting + blasting driving + advance grouting". Drive the sectional drilling roadway 12 from the footwall at the bottom of the middle section to the boundary of the ore body near the footwall. When the economic and technical indexes of the ore body mining in the area where the four-way floor curtain 13 is to be formed are reasonable (i.e., sales revenue ≥ mining cost), continue to extend the sectional drilling roadway 12 to the hanging wall of the ore body, adopt "heading mining + subsequent filling" for the bottom ore body, form the four-way floor curtain 13, and the method of forming the four-way floor curtain 13 is economically reasonable. When the economic and technical indexes of the ore body mining are unreasonable (i.e., sales revenue < mining cost), do not conduct mining, directly construct bottom grouting holes 16 in the ore body perpendicular to the hanging wall direction in the sectional drift 5, conduct advance grouting on the ore body in the area where the curtain is to be formed, and form a four-way floor curtain 13 after grouting. The hole spacing of the bottom grouting holes 16 is 3 - 5 m, so that the slurry can penetrate along the rock mass fissures and the slurry in adjacent bottom grouting holes 16 can overlap, forming a complete four-way floor curtain 13. The thickness of the four-way floor curtain 13 ≥ 4 m to prevent water inrush from the bottom of the middle section into the mining area of this middle section. After forming the four-way floor curtain 13, then drive a sectional drilling roadway 12 from the footwall to the hanging wall on the upper surface of the four-way floor curtain 13 to conduct the extraction work of the bottommost section.

[0051] In this step, driving the sectional drilling roadway 12 provides a working space for the four-way floor curtain 13 and subsequent medium-deep hole mining. Through the mutual cooperation of the one-way filling body curtain 6, the two-way filling body curtain 7, and the three-way hanging wall curtain 11, the ore body in the water hazard mining area 1 is transformed into an ore body in an ordinary mining area without water hazard threat. Then, through driving the mining preparation engineering of each section, medium-deep hole caving mining is realized. In addition, before the extraction of this middle section, the ore body at the corresponding position in the vertical direction of the previous middle section has usually completed the extraction and filling operations. At this time, the filling body of the previous middle section can be used as a five-way roof curtain for this middle section to further improve the safety of the water hazard mining area 1. At the same time, the four-way floor curtain 13 of this middle section can also be used as a five-way roof curtain for the next middle section, greatly reducing the grouting cost.

[0052] S5. Repeat steps S2 - S4 to extract the remaining middle sections until the extraction of the entire ore body is completed.

[0053] In the technical solution of the embodiment of the present application, first, the mining sequence of the ore body is reasonably arranged, the first general mining area 2 and the second general mining area 3 are mined, and the filling bodies formed by the previous mining projects are fully utilized as the first-direction filling body curtain 6 and the second-direction filling body curtain 7, which improves efficiency, saves costs, and has a good water-blocking effect. Then, the auxiliary ramp 4, the sectional drift 5, the top rock-drilling roadway 8, the roof drift grouting roadway 9, and the sectional rock-drilling roadway 12 and other development projects are used to connect the middle sections to be mined, and the third-direction upper plate curtain 11 and the fourth-direction bottom plate curtain 13 are respectively formed at the upper plate and the bottom plate positions of the ore body, so as to establish a complete "four-directional space curtain" in the four directions of the upper plate, the bottom plate, and the two sides of the ore body in the water disaster mining area 1, isolate the possible water inrush points around the water disaster mining area 1, avoid the influence of groundwater on the water disaster mining area 1, and make the water disaster mining area 1 in a water-free area. After the multi-directional space curtain is formed, the sectional rock-drilling roadway 12 of each section of the water disaster mining area 1 is driven from the lower plate to the upper plate, and the medium-deep hole mining of the ore body is carried out, so as to realize safe and high-efficiency mining under complex water inrush conditions. This method is safe and reliable, and the process is flexible. The hole layout plan can be adjusted at any time according to the ore body and water inrush conditions, saving the grouting cost to the greatest extent, improving the ore mining rate, reducing the loss and dilution rate, and increasing the resource utilization rate of the mine.

[0054] Further, in some embodiments, as Figure 1 shown, in step S2, a non-water-inrushing safety area 14 is provided between the water disaster mining area 1, the first general mining area 2, and the second general mining area 3, and the length of the safety area 14 is not less than 10 m.

[0055] In the technical solution of the embodiment of the present application, by setting a section of safety redundancy length, that is, the safety area 14, between the water disaster mining area 1, the first general mining area 2, and the second general mining area 3, the influence of the water disaster mining area 1 on the mining process of the first general mining area 2 and the second general mining area 3 is reduced, ensuring the safe and efficient mining of the first general mining area 2 and the second general mining area 3; at the same time, the widths (i.e., the lengths along the strike of the ore body) of the subsequent third-direction upper plate curtain 11 and the fourth-direction bottom plate curtain 13 are expanded, ensuring to the greatest extent that the formed "four-directional space curtain" can achieve efficient water blocking in the water disaster mining area 1.

[0056] Further, in some embodiments, as shown in FIG. 1, the first-direction filling body curtain 6 and the second-direction filling body curtain 7 are embedded in the upper plate, that is, the thicknesses of the first-direction filling body curtain 6 and the second-direction filling body curtain 7 are greater than the thickness of the water disaster mining area 1, and the thicknesses of the first-direction filling body curtain 6 and the second-direction filling body curtain 7 embedded in the upper plate are ≥1 m. Specifically, during the mining and filling processes of the first general mining area 2 and the second general mining area 3, a certain thickness is mined and filled more upward to the upper plate.

[0057] In the technical solution of the embodiment of the present application, by setting the thicknesses 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 disaster mining area 1 and embedding the one-way filling body curtain 6 and the two-way filling body curtain 7 in the hanging wall, it is convenient to overlap with the three-way hanging wall curtain 11 formed in the hanging wall subsequently, further improving the water blocking effect.

[0058] Further, in some embodiments, the strength of the filling body within 3 to 5 m on the side of the one-way filling body curtain 6 and the two-way filling body curtain 7 close to the safety area 14 is ≥5 MPa.

[0059] 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 disaster mining area 1 to be a high-strength cemented filling body, the strengths of the one-way filling body curtain 6 and the two-way filling body curtain 7 close to the hanging wall water-bearing area 15 are better, further improving the water blocking effect.

[0060] Further, in some embodiments, the ore body is a medium-thick or thick and large ore body, and the dip angle of the ore body >30°.

[0061] In the technical solution of the embodiment of the present application, by setting the ore body to be a medium-thick or thick and large ore body, after forming the "four-way space curtain", the amount of mined ore is relatively large, thus achieving the effect of reducing costs. By setting the dip angle of the ore body to >30°, the inclination of the ore body is relatively large, facilitating the smooth formation of the hanging wall grouting holes 10 and the three-way hanging wall curtain 11.

[0062] Further, in some embodiments, in step S3, the length of the roof drift along the vein 9 is equal to the sum of the lengths of the water disaster mining area 1 and the safety areas 14 on both sides, that is, the roof drift along the vein 9 communicates with the one-way filling body curtain 6 and the two-way filling body curtain 7;

[0063] The hanging wall grouting holes 10 are arranged in 1 to 3 rows, and the hanging wall grouting holes 10 in adjacent rows are arranged staggeredly; the row spacing of the hanging wall grouting holes 10 <3 m, and the hole spacing in each row is 3 to 5 m; the length of the hanging wall grouting holes 10 is equal to the inclined length of the section; the hanging wall grouting holes 10 extend along the ore body strike into the safety area 14, and the distance from the end hanging wall grouting holes 10 to the one-way filling body curtain 6 and the two-way filling body curtain 7 <1 m; specifically, the number of rows of the hanging wall grouting holes 10 depends on the water inflow in the hanging wall. When the water inflow in the hanging wall is large, the number of rows of the hanging wall grouting holes 10 is large.

[0064] In the technical solution of the embodiment of the present application, by setting the length of the roof drift along the vein 9 to be equal to the sum of the lengths of the water hazard mining area 1 and the safety areas 14 on both sides, the roof drift along the vein 9 is connected to the first filling body curtain 6 and the second filling body curtain 7 on both sides, providing favorable conditions for setting a wider upper wall grouting holes 10 and the third upper wall curtain 11. The number of rows of the upper wall grouting holes 10 is set according to the water inflow of the upper wall to ensure that the formed third upper wall curtain 11 is thicker and improve the water blocking effect. By arranging the upper wall grouting holes 10 in a staggered manner between adjacent rows, and at the same time by reasonably setting the row spacing and hole spacing of each row of the upper wall grouting holes 10, the slurry can overlap after infiltrating along the rock mass fissures in adjacent upper wall grouting holes 10, forming a complete and thick third upper wall curtain 11, improving the water blocking effect. By reasonably setting the distance between the upper wall grouting holes 10 at the end and the first filling body curtain 6 and the second filling body curtain 7, the slurry can better overlap with the first filling body curtain 6 and the second filling body curtain 7 on both sides after infiltrating along the rock mass fissures, so that the third upper wall curtain 11 can better overlap with the first filling body curtain 6 and the second filling body curtain 7 to form a whole.

[0065] Further, in some embodiments, the grouting uses an ultra-fine grouting material with a water-cement mass ratio of 0.7 - 0.9:1, the initial setting time ≤ 30 min, and the final grouting pressure is 2 - 3 times the hydrostatic pressure; the 3-day compressive strength of the slurry of the third upper wall curtain 11 ≥ 15 MPa. Specifically, the preferred water-cement mass ratio of the grouting is 0.8:1.

[0066] In the technical solution of the embodiment of the present application, by reasonably setting the water-cement mass ratio of the grouting, a grouting material with good injectability is formed, improving the water isolation effect of the slurry. By reasonably controlling the initial setting time of the slurry after grouting, the final grouting pressure, and the 3-day compressive strength of the slurry, a hard and highly water-blocking third upper wall curtain 11 is formed after the slurry solidifies.

[0067] Further, in some embodiments, the mid-section mining is specifically as follows: In the upward medium-deep hole drift 12 at the bottom of the mid-section, upward medium-deep holes are constructed, starting from the third upper wall curtain 11, retreating mining and ore drawing, mining the remaining sections from bottom to top, and then filling until the entire mid-section mining is completed. Specifically, the height of the upward medium-deep hole drift 12 is 4.2 m, adapting to the requirements of the medium-deep hole mining process. In the vertical height direction, the bottom of the upward medium-deep hole drift 12 is closely adjacent to the top of the fourth floor curtain 13 for tunneling construction.

[0068] In the technical solution of the embodiment of the present application, on the basis of forming a high-resistance water "four-way space curtain", the water hazard mining area 1 is transformed into an ordinary safe mining area. Then, the medium-deep hole process with a large production capacity is used to mine the water hazard mining area 1. Through the mutual cooperation of the "four-way space curtain" and the medium-deep hole mining process, the safe, efficient and green mining of the difficult-to-mine ore body under the complex water inrush conditions in the hanging wall is realized, the ore mining rate is increased, the loss and dilution rate is reduced, which is of great significance to the mines threatened by water hazards.

[0069] Further, in some embodiments, in step S4, when the economic and technical indexes of the ore body mining in the area of the proposed four-way floor curtain 13 are reasonable (i.e., the sales revenue ≥ the mining cost), the "heading mining + subsequent backfilling" is adopted for the bottom ore body to form the four-way floor curtain 13; when the economic and technical indexes of the ore body mining are unreasonable (i.e., the sales revenue < the mining cost), only advanced grouting is carried out on the bottom ore body to form the four-way floor curtain 13.

[0070] In the technical solution of the embodiment of the present application, a suitable method is selected to form the four-way floor curtain 13 according to the economic rationality of the ore body mining, so as to reduce the cost and improve the economic benefit.

[0071] Further, in some embodiments, in step S2, the position of the water-bearing body is detected by combining "geophysical exploration + drilling", and it is marked as the water hazard mining area 1 that may be threatened by water hazards. Specifically, after the development project of this section is completed, the general delineation of the water-bearing body range of the whole section is completed by using geophysical exploration equipment to ensure the safety of the normal driving operation of the development heading. When approaching the water-bearing body influence area, detailed water exploration work is carried out again by combining geophysical exploration + drilling before each driving until the range of the final water hazard mining area 1 is determined.

[0072] In the technical solution of the embodiment of the present application, the water-bearing body is detected by combining "geophysical exploration + drilling", and the detection accuracy is high, which provides favorable conditions for the formation of the "four-way space curtain", realizes efficient water blocking, and thus transforms the water hazard mining area 1 into a safe mining area.

[0073] It should be noted that the present application is not limited to the above embodiments. The above embodiments are only examples, and the embodiments with the same structure and the same effect as the technical idea within the technical solution scope of the present application are included in the technical scope of the present application. In addition, within the scope of not departing from the main idea of the present application, various deformations that can be thought of by those skilled in the art are applied to the embodiments, and other ways constructed by combining some constituent elements of the embodiments are also included in the scope of the present application.

Claims

1. A multi-directional spatial curtain medium-deep hole mining method under the condition of complex water inrush from the upper floor, characterized in that, It includes the following steps: S1. Divide the ore body into levels along the vertical height, divide each level into sublevels, and conduct stoping from top to bottom with each level as a unit. Drive an auxiliary ramp in the footwall to connect different levels and sublevels; S2. Detect the position of the water-bearing body in the ore body, divide the level along the strike of the ore body into a water hazard mining area and a first ordinary mining area and a second ordinary mining area on both sides of the water hazard mining area; Drive sublevel headings along the strike of the ore body in the footwall, stop and fill the first ordinary mining area and the second ordinary mining area to form a unidirectional filling body curtain and a bidirectional filling body curtain; S3. Drive a top rock drilling heading from the footwall to the hanging wall at the top of the level, drive a roof drift along the strike of the ore body in the hanging wall, construct a number of upper wall grouting holes parallel to the dip angle of the ore body in the roof drift along the strike, and form a three-way upper wall curtain after grouting; S4. Drive a sublevel rock drilling heading from the footwall to the boundary of the ore body near the footwall at the bottom of the level, stop and fill or pre-grout the bottom ore body according to the mining economic indexes of the ore body to form a four-way floor curtain; Drive the sublevel rock drilling headings of each sublevel from the footwall to the hanging wall and stop different sublevels; S5. Repeat steps S2 - S4 to stop the remaining levels.

2. The multi-directional spatial curtain medium-deep hole mining method under the complex water inrush condition of the upper plate according to claim 1, wherein In step S2, a water-free safety area is provided between the water hazard mining area and the first ordinary mining area and the second ordinary mining area; The length of the safety area is not less than 10 m.

3. The multi-directional spatial curtain medium-deep hole mining method under the complex water inrush conditions of the upper disk according to claim 2, characterized in that, The unidirectional filling body curtain and the bidirectional filling body curtain are embedded in the hanging wall, and the thickness of the unidirectional filling body curtain and the bidirectional filling body curtain embedded in the hanging wall is ≥1 m.

4. The multi-directional spatial curtain medium-deep hole mining method under the complex water inrush conditions of the upper plate according to claim 3, characterized in that, The strength of the filling body within 3 - 5 m on the side of the unidirectional filling body curtain and the bidirectional filling body curtain close to the safety area is ≥5 MPa.

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

6. The multi-directional spatial curtain medium-deep hole mining method under the complex water inrush conditions of the upper plate according to claim 5, characterized in that In step S3, the length of the roof drift along the strike is equal to the sum of the lengths of the water hazard mining area and the safety areas on both sides; The upper wall grouting holes are arranged in 1 - 3 rows, and the upper wall grouting holes between adjacent rows are arranged staggeredly; The row spacing of the upper wall grouting holes < 3 m, and the hole spacing of each row is 3 - 5 m; The length of the upper wall grouting holes is equal to the inclined length of the level; The upper wall grouting holes extend along the strike of the ore body into the safety area, and the distance from the end upper wall grouting hole to the unidirectional filling body curtain and the bidirectional filling body curtain < 1 m.

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

8. The multi-directional spatial curtain medium-deep hole mining method under the complex water inrush conditions of the upper plate according to claim 7, characterized in that, The specific stoping of the level is as follows: Construct upward medium-deep holes in the sublevel rock drilling headings at the bottom of the level, start from the three-way upper wall curtain, conduct retreating stoping and ore drawing, and stop the remaining sublevels from bottom to top and then fill.

9. The multi-directional spatial curtain medium-deep hole mining method for the upper plate under complex water inrush conditions according to claim 1, characterized in that In step S4, when the sales revenue from the ore body mining within the four-way floor curtain area to be formed ≥ the mining cost, the "drift mining + subsequent backfilling" method is adopted for the bottom ore body to form the four-way floor curtain; when the sales revenue from the ore body mining < the mining cost, only advanced grouting is carried out for the bottom ore body to form the four-way floor curtain.

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

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