A high-efficiency non-dilution filling mining method for mines in cold regions

Abstract

The application provides a high-efficiency non-dilution filling mining method in a cold region mine, which comprises the following steps: arranging a panel along the strike direction of a ore body and dividing the ore body into rooms and pillars; using the drill-and-blast method to excavate and mine alternately, one-step room mining is completed, and a filling pipe is laid at the highest point of the roof of the empty area; an anchoring device is arranged on the ore pillar rock mass on both sides of the empty area, and the anchoring devices are connected by a steel wire rope; a horizontal water pipe and a vertical water pipe are installed on the steel wire rope in a binding manner to form a water pipe network, and the water inlet and the water outlet of the water pipe network pass through a filling retaining wall; the filling retaining wall is built, and filling slurry is filled into the empty area of the one-step room from the filling pipe; when the filling slurry in the empty area of the one-step room is completely connected to the roof, warm water with a temperature of 40 DEG C to 60 DEG C is circulated and fed into the water pipe network; after the filling body is cured to the design strength, the ore pillars on both sides of the empty area are simultaneously mined; the application adopts active heat preservation and curing of the filling body, and the curing period of the filling body to reach the design strength is shortened.

Description

Technical Field

[0001] This application relates to the field of underground mining technology for metals and non-metals, and in particular to a high-efficiency, non-depletion-reducing backfilling mining method for cold-region mines. Background Technology

[0002] Backfill mining is a common mining method widely used due to its adaptability and high ore recovery rate. However, it requires high strength of the backfill body, often ≥5MPa, has low efficiency in single-stope operations, and typically employs a "three-days-ahead-one-day" mining pattern to ensure operational safety (e.g., ...). Figure 1 As shown), this is because the stope length in the access backfill mining method is usually very long, making roof connection work difficult. If a "one-off" mining mode is adopted (such as...), Figure 2 As shown in the image, poor roof connection could lead to an excessively large exposed roof area, potentially causing roof collapses and other safety accidents, seriously threatening the safety of personnel and equipment. Furthermore, if the pillars on both sides of the backfill are mined simultaneously, as shown in the image... Figure 2 As shown, after the first stope is mined, it is backfilled to form a backfill body. Then, the second stope is mined at the same time. The disturbance caused by blasting and ore extraction can easily lead to the collapse of the backfill body. At best, it will mix in ore and cause dilution, and at worst, it will endanger the lives of the workers. Therefore, the conventional approach backfilling method usually adopts the "one-out-of-three" mining mode. Although the operation efficiency is low, it is still within an acceptable range.

[0003] With the rapid development of backfill mining technology and the surge in mineral resource development in high-altitude and cold regions, low-temperature curing is a common problem in underground mine backfilling. Sustained low temperatures lead to the deterioration of the mechanical properties of the backfill, lengthening the curing period to reach the design strength, and potentially preventing it from reaching the design strength of the mining method altogether. Related research indicates that below 10℃, the strength of the backfill will decrease to 30%–40% of that at room temperature. Furthermore, mining operations in high-altitude and cold regions are costly, primarily due to the extreme working conditions that reduce the efficiency of personnel and equipment. Therefore, the efficiency of mining methods determines the mine's production costs and the company's profit level. The shortcomings of the "one-in-three" mining model become increasingly apparent in cold regions, with six operational cycles becoming increasingly difficult. Figure 1 The combined effect of the low-temperature mining sequence and the further decline in mining-backfilling cycle efficiency means that the extra ore recovered by the backfilling method cannot offset the increased mining costs due to the decreased efficiency, thus losing its application value. Enterprises also have to increase the cut-off grade due to the inability to make a profit, resulting in the waste of ore resources. At the same time, due to the low strength and poor homogeneity of the backfill body under low temperature curing, the backfill body is more prone to spalling when disturbed, leading to the dilution of the ore grade in adjacent stops, which also increases mining and beneficiation costs and weakens the enterprise's profitability.

[0004] The common solution is to develop filling cementitious materials that are more suitable for low-temperature conditions, and at the same time increase the amount of cementitious materials added to the unit volume of filling material, so as to improve the strength of the filling material in cold regions and shorten the curing cycle of the filling material. However, this method is very expensive, and in actual production, it can only appropriately shorten the curing cycle, and cannot fundamentally solve the shortcomings exposed by the "three-times-one-times-around" mining mode combined with the cold environment.

[0005] In summary, there is an urgent need for a new approach backfilling mining method in high-altitude and cold regions, which optimizes the mining process from "mining every three days" to "mining every one day." This method would shorten the cycle, dramatically increase production efficiency, eliminate mining waste, and completely solve the problems of high production difficulty, low efficiency, and high cost in high-altitude and cold regions. Summary of the Invention

[0006] The purpose of this application is to overcome the above-mentioned shortcomings of the prior art and provide a high-efficiency, non-depletion-reducing backfilling mining method for cold-region mines. It adopts active thermal insulation backfill curing, which shortens the curing cycle for the backfill to reach the design strength. At the same time, the active water pipe network also serves as the skeleton of the backfill. Combined with the prestressing during backfilling, after the backfill is exposed on both sides, the high confining pressure and the "steel reinforcement" effect of the water pipe network further enhance the overall mechanical properties of the backfill.

[0007] To achieve the above objectives, the technical solution adopted in this application is as follows: A high-efficiency, non-drainage-reducing backfilling mining method for cold-region mines includes the following steps: S1: Panels are arranged along the strike of the ore body, and the panels are divided into stops and pillars within the panel perpendicular to the strike of the ore body. S2: The drilling and blasting method is used to excavate and mine along the length of the stope from the layered connecting roadway of the panel. The mining sequence is one step at a time. After the stope is mined in one step, a goaf is formed. A filling pipe is laid at the highest point of the roof of the goaf. S3: Anchoring devices are installed on the rock mass of the access pillar on both sides of the stope of the first step, and the anchoring devices correspond one-to-one with the side wall of the stope of the first step, and each one-to-one anchoring device is connected by two steel wire ropes. S4: Secure the horizontal water pipes to the steel wire ropes by binding. After the horizontal water pipes are installed, connect the vertical water pipes using multi-connector joints to create an insulated space within the open area, thus forming a water pipe network within the open area. Lead the leftmost water pipe of the bottom layer out through the unbuilt filling retaining wall as the inlet of the water pipe network. Lead the rightmost water pipe of the bottom layer out through the unbuilt filling retaining wall as the outlet of the water pipe network. S5: Construct and fill retaining walls to seal off the empty area of ​​the first-stage mine; S6: The paste filling slurry prepared at the surface filling station begins to enter the empty area of ​​the first-stage stope through the filling pipe; S7: After the filling slurry in the empty area of ​​the first-stage mine has completely reached the top, warm water of 40℃~60℃ is circulated into the water pipe network. S8: Once the void filling body of the first-stage stope has been cured to the design strength, simultaneous mining of the pillars on both sides of the access road begins.

[0008] In the technical solution of this application, the structure of the void area is formed by anchoring devices and steel wire ropes, and a water pipe network is installed on the steel wire ropes. In this way, the temperature range can be maintained during filling by continuously circulating warm water, which shortens the curing cycle for the filling body in cold regions to reach the design strength. At the same time, the water pipe network and steel wire ropes can also be used as the framework for filling, further improving the mechanical properties of the filling body.

[0009] As a further improvement of this application, in step S2, smooth blasting is used to control the flatness of the roadway walls during the first-step mining and excavation of the stope, with a hole spacing of 0.5 to 0.7 m and a row spacing of 0.8 to 1.0 m; the cross-sectional dimensions of the excavation approach are 3×3 m to 6×6 m.

[0010] As a further improvement of this application, the periphery of the anchoring device is stitched and bonded to the heat insulation pad. The heat insulation pad is composed of a double layer of fabric and an airtight inner liner. The heat insulation pad is fixed to the rock wall by the anchoring device, and the heat insulation pad covers the entire rock wall of the empty area sidewall. The air inlet pipe of the heat insulation pad leads out to the filling retaining wall that has not yet been built, serving as the air inlet of the heat insulation pad cavity.

[0011] In the technical solution of this application, the heat insulation pad is designed to keep the filling area heated by circulating water insulated, thereby further reducing the curing time of the filling body.

[0012] As a further improvement of this application, the insulation pad includes a dense insulation pad zone in the middle and an expanded insulation pad zone at the edge. The expanded insulation pad zone can continue to expand when the gas pressure increases. At the beginning of filling, the air inlet pipe is opened to inject 0.3MPa gas into the insulation pad, and the insulation pad cavity expands to a thickness of 30-50mm. In the final stage of the first-stage stope connection, the air inlet pipe is switched to inject 0.8MPa gas into the insulation pad. The dense insulation pad zone still maintains a cavity expansion thickness of 30-50mm, but the expanded insulation pad zone continues to expand, with an expansion thickness of 500-800mm, so that the voids formed by incomplete filling and seepage are filled. This process is maintained until the filling material initially solidifies, so that the filling material is completely connected to the roof.

[0013] In the technical solution of this application, the dual-zone design of the heat insulation pad combined with low-pressure and high-pressure gas injection can compress the edge and top plate of the filling body during the filling process, ensuring that the filling body is fully in contact with the top plate and ensuring stable support during subsequent pillar mining. At the same time, the heat insulation pad can also serve as a buffer space for pillar blasting mining, further ensuring the stability of the stope filling body during subsequent blasting.

[0014] As a further improvement of this application, the anchoring device has a screw tightening device, which applies prestress to the wire rope to tighten the wire rope between the anchoring devices.

[0015] In the technical solution of this application, the spiral tightening device keeps the wire rope in a taut state, thus ensuring that it can play an excellent skeleton support role as a filling body support.

[0016] As a further improvement to this application, the panel length is 30-50m, the width is 25-55m, the stope or pillar width is 3m-6m, and the stope length is the same as the panel length.

[0017] As a further improvement of this application, the water inlet is connected to a water inlet pipe, which is connected to a constant temperature water tank via an axial flow water pump, and the water outlet is connected to the constant temperature water tank via an water outlet pipe.

[0018] As a further improvement of this application, the constant temperature water tank is equipped with an intelligent heater that can set the temperature, and the constant temperature water tank is also connected to an external water supply pipe.

[0019] As a further improvement of this application, the anchoring device is fixed to the rock mass of the access pillar by drilling and anchoring agent, and the spacing of the anchoring device is 1m×1m~2m×2m.

[0020] As a further improvement to this application, the horizontal and vertical water pipes that make up the water pipe network are all made of thin-skinned steel pipes with specifications ranging from DN25 to DN50.

[0021] Compared with the prior art, the beneficial effects of this application are as follows: 1. Active insulation backfill curing in cold-region mines, shortening the curing cycle for the backfill to reach its design strength.

[0022] 2. The active insulation network also serves as the skeleton of the filling body. Combined with the prestressing during filling, the high confining pressure and the "steel reinforcement" effect of the insulation network after the filling body is exposed on both sides further enhance the overall mechanical properties of the filling body.

[0023] 3. The insulation layer also serves as a forced roof support, with the fully connected filling material effectively supporting the roof. The high-quality filling material acts as a support pillar, making it possible to mine pillars from both sides simultaneously. This optimizes the traditional "three-times-one-times-mining" model into a "one-times-one-times-mining" model. It can significantly shorten the mining and filling cycle efficiency in cold-region mines, resulting in a substantial reduction in production costs.

[0024] 4. Complete roof and backfill sidewalls without sidewall fragmentation not only ensure the safety of the mining area but also achieve zero dilution in the ore recovery process. Attached Figure Description

[0025] To more clearly illustrate the technical solution of this application, the accompanying drawings used in this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the "one-times-every-three-mining" recovery mode; Figure 2 This is a schematic diagram of the "one-time-everything" mining mode; Figure 3 A cross-sectional view of a single-step stope recovery process; Figure 4 for Figure 3 Sectional view of AA.

[0027] Figure 5 for Figure 3 A cross-sectional view of BB.

[0028] Figure 6 for Figure 3 A sectional view of CC.

[0029] Figure 7 This is a magnified view of a section of the insulation pad and water pipes.

[0030] The text labels shown in the image indicate: 1. One-step stope; 2. Access pillar; 3. Filling retaining wall; 4. Anchoring device; 5. Steel wire rope; 6. Insulation pad; 7. Air inlet pipe; 8. Water pipe network; 9. External water supply pipe; 10. Constant temperature water tank; 11. Heater; 12. Axial flow water pump; 13. Water inlet pipe; 14. Water outlet pipe; 601. Dense area of ​​insulation pad; 602. Enlarged area of ​​insulation pad; 801. Horizontal water pipe; 802. Multi-port connector; 803. Vertical water pipe; 804. Insulated space; 805. Water inlet; 806. Water outlet. Detailed Implementation

[0031] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0033] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0034] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0036] For ease of explanation, the following embodiments use an example of a high-efficiency, non-drainage-reducing backfilling mining method for cold-region mines according to an embodiment of this application.

[0037] Please refer to Figures 2-7 This application discloses a high-efficiency, non-dilution-reducing backfilling mining method for cold-region mines, comprising the following steps: S1: Panels are arranged along the strike of the ore body, and the panels are divided into stops and pillars within the panel perpendicular to the strike of the ore body. S2: The drilling and blasting method is used to excavate and mine along the length of the stope from the layered connecting roadway of the panel. The mining sequence is one mining every other step. After the first step stope is mined out, a goaf is formed. A filling pipe is laid at the highest point of the roof of the goaf. S3: Anchoring devices 4 are installed on the rock mass of the access pillar on both sides of the first-step stope void, and the anchoring devices 4 correspond one-to-one with the side wall of the first-step stope void. Each one-to-one anchoring device is connected by two steel wire ropes 5 with a diameter of 2mm to 5mm. S4: Secure the horizontal water pipe 801 to the steel wire rope by binding. After the horizontal water pipe 801 is installed, connect the vertical water pipe 803 with the multi-connector 802 to form a uniform 1m×1m~2m×2m insulation space 804 in the empty area, that is, form a water pipe network 8 in the empty area; lead the leftmost water pipe of the bottom layer out to the filling retaining wall 3 that has not yet been built, as the water inlet 805 of the water pipe network; lead the rightmost water pipe of the bottom layer out to the filling retaining wall 3 that has not yet been built, as the water outlet 806 of the water pipe network. S5: Construct and fill retaining wall 3 to seal off the empty area of ​​the first-stage mine; S6: The paste filling slurry prepared at the surface filling station begins to enter the empty area of ​​the first-stage stope through the filling pipe; S7: After the filling slurry in the empty area of ​​the first-step mine has completely reached the top, warm water of 40℃~60℃ is circulated into the water network 8. S8: After the void filling body of the first-step stope has been cured to the design strength, simultaneous mining of the two side access pillars 2 begins.

[0038] In the above embodiments, the anchoring device 4 and the steel wire rope 5 form the structure of the void area, and the water pipe network 8 is installed on the steel wire rope 5. In this way, the temperature range can be maintained during filling by continuously circulating warm water, which shortens the curing cycle for the filling body in cold regions to reach the design strength. At the same time, the water pipe network 8 and the steel wire rope 5 can also be used as the filling frame to further improve the mechanical properties of the filling body.

[0039] Furthermore, in some implementation examples, in step S2, smooth blasting is used to control the flatness of the roadway walls during the first-step mining and excavation of the stope, with a hole spacing of 0.5 to 0.7 m and a row spacing of 0.8 to 1.0 m; the cross-sectional dimensions of the excavation approach are 3×3 m to 6×6 m.

[0040] Furthermore, in some implementation examples, the perimeter of the anchoring device 4 is stitched and bonded to the heat insulation pad 6. The heat insulation pad 6 is composed of a double layer of fabric and an airtight inner liner. The heat insulation pad 6 is fixed to the rock wall by the anchoring device 4, and the heat insulation pad 6 covers the entire rock wall of the empty area. The air inlet pipe 7 of the heat insulation pad 6 leads out to the filling retaining wall that has not yet been built, serving as the air inlet of the cavity of the heat insulation pad 6.

[0041] In the above embodiments, the design of the heat insulation pad 6 can keep the filling area heated by circulating water warm, further reducing the curing time of the filling body.

[0042] Furthermore, in some implementation examples, the insulation pad 6 includes a dense insulation pad zone 601 in the middle and an expanded insulation pad zone 602 at the edge. The expanded insulation pad zone can continue to expand when the gas pressure increases. At the beginning of filling, the air inlet pipe is opened to inject 0.3MPa gas into the insulation pad, and the insulation pad cavity expands to a thickness of 30-50mm. In the final stage of the first-step stope connection, the air inlet pipe is switched to inject 0.8MPa gas into the insulation pad. The dense insulation pad zone 601 still maintains a cavity expansion thickness of 30-50mm, but the expanded insulation pad zone 602 continues to expand, and its expansion thickness can reach a maximum of 500-800mm, so that the unfilled and water-bleeding voids are filled. This process is maintained until the filling material initially solidifies, so that the filling material is completely connected to the roof.

[0043] In the above embodiments, the dual-zone design of the heat insulation pad 6, combined with low-pressure and high-pressure gas injection, can compress the edges and top plate of the filling body during the filling process, ensuring that the filling body is fully in contact with the top plate and ensuring stable support during subsequent pillar mining. At the same time, the heat insulation pad can also serve as a buffer space for pillar blasting mining, further ensuring the stability of the stope filling body during subsequent blasting.

[0044] Furthermore, in some implementation examples, the anchoring device 4 has a screw-tightening device, which applies prestress to the wire rope 5, thereby tauting the wire rope 5 between the anchoring devices 4.

[0045] In the above embodiments, the spiral tightening keeps the wire rope 5 in a taut state, thus ensuring that it can play an excellent skeletal support role as a filling body support.

[0046] Furthermore, in some implementation examples, the panel length is 30-50m, the width is 25-55m, the stope or pillar width is 3m-6m, and the stope length is the same as the panel length.

[0047] Furthermore, in some implementation examples, the water inlet 805 is connected to the water inlet pipe 13, the water inlet pipe 13 is connected to the constant temperature water tank 10 through the axial flow water pump 12, and the water outlet 806 is connected to the constant temperature water tank 10 through the water outlet pipe 14.

[0048] Furthermore, in some implementation examples, the constant temperature water tank 10 is equipped with an intelligent heater 11 that can set the temperature, and the constant temperature water tank 10 is also connected to an external water supply pipe 9.

[0049] Furthermore, in some implementation examples, the anchoring device 4 is fixed to the rock mass of the access pillar 2 by drilling and anchoring agent, and the spacing of the anchoring device 4 is 1m×1m~2m×2m.

[0050] Furthermore, in some implementation examples, the horizontal water pipes 801 and vertical water pipes 803 that make up the water pipe network 8 are both made of thin-skinned steel pipes with specifications of DN25 to DN50.

[0051] Specific embodiments are listed below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific technologies or conditions are not specified in the embodiments, they shall be performed in accordance with the technologies or conditions described in the literature in this field or in accordance with the product manual.

[0052] This embodiment provides a detailed explanation of a high-efficiency, non-drainage-reducing approach filling mining method for mines in cold regions.

[0053] like Figure 2-7 As shown, for a copper mine in a cold region, a panel is arranged along the strike of the ore body. The panel is 40m long and 30m wide. The panel is divided into stops and pillars perpendicular to the strike of the ore body. The width of the stops or pillars is 5m, and the length of the stop is the same as the length of the panel, which is 40m.

[0054] Mining is carried out along the length of the stope using the drill-and-blast method from the interlayer connecting roadway of the block, with a mining sequence of one stope every other stope. The cross-sectional dimensions of the excavation approach are 4×4m. To reduce spalling of the backfill material in adjacent stops, smooth blasting is used during the excavation of stope 1 in the first-stage mining stage to control the flatness of the roadway walls. The spacing between boreholes is 0.6m, and the row spacing is 1.0m. No backfilling is carried out before stope 1 reaches the stope boundary. The two side roadway pillars 2 serve as supports to ensure the stability of the void formed after stope 1 is mined. After stope 1 is mined, a backfill pipe is laid at the highest point of the void roof to serve as a channel for backfill slurry to fill the void.

[0055] Before the construction of the filling retaining wall 3 of the first-stage stope 1, anchoring devices 4 are installed on the rock mass of the approach pillar 2 on both sides of the stope void. The anchoring devices 4 are fixed to the rock mass of the approach pillar 2 by drilling and anchoring agent. The spacing of the anchoring devices 4 is about 1.8m×1.8m. The anchoring devices 4 correspond one-to-one with the side wall of the stope void of the first-stage stope 1. The anchoring devices 4 have a screw tightening device. Each corresponding anchoring device 4 is connected by two 4mm diameter steel wire ropes 5. The screw tightening device applies prestress to the steel wire ropes 5, so that the steel wire ropes between the anchoring devices 4 are taut and form a certain prestress, which is offset by the force of the anchoring in the rock mass.

[0056] Integrated with the anchoring device 4 is a heat insulation pad 6, which consists of a double-layered fabric and an airtight inner liner, providing excellent insulation and extremely poor heat conduction. The anchoring device 4 is a 0.3m diameter circular object that adheres to the rock wall, with its perimeter stitched and bonded to the heat insulation pad 6. The heat insulation pad 6 is well-sealed and can be fixed to the rock wall by the anchoring device 4, covering the entire sidewall of the empty area. Air can be injected into the heat insulation pad 6 through the air inlet pipe 7, which provides high-pressure gas in two levels: low pressure 0.3MPa and high pressure 0.8MPa. When the heat insulation pad 6 is filled with low-pressure 0.3MPa gas, its cavity expands to a thickness of approximately 40mm. Since the height of a typical mining area does not exceed 10m, the maximum fluid pressure formed by filling the entire area with air using the filling slurry is only about 0.2MPa. Therefore, the heat insulation pad 6 is designed for low pressure 0.3MPa. When the gas is filled with 0.8MPa, its shape remains unaffected by the filling slurry. When the insulation pad 6 is filled with high-pressure 0.8MPa gas, its cavity expansion state is divided into two types. The dense area 601 of the insulation pad still maintains a cavity expansion thickness of 40mm, but the expanded area 602 of the insulation pad can expand to a greater extent due to the different pressure-sensitive materials used, with a maximum expansion thickness of 600mm. The main function of the expanded area 602 of the insulation pad is to address the issue that when the inlet pipe is being filled, the top plate is difficult to completely fill, and small voids will form after the secreted water is drained. By switching the pressure level of the inlet pipe 7 and injecting high-pressure 0.8MPa gas, the expanded area 602 of the insulation pad expands further, filling the voids formed by the incomplete filling and secreted water. This process can be maintained until the filling material initially solidifies, and the final effect is that the filling material is completely connected to the top plate.

[0057] A horizontal water pipe 801 made of thin-walled steel pipe is installed and fixed to the steel wire rope 5 between the anchoring devices 4 by binding. After the horizontal water pipe 801 is installed, the vertical water pipe 803 is connected by a tee / cross joint (multi-way connector 802) to form a uniform 2m×2m insulation space 804 between the water pipes in the empty area. The specifications of the horizontal and vertical water pipes are DN35. The pipes are connected by threads or quick clamps to ensure the convenience of on-site installation. After the aforementioned empty area water pipe network is formed, the leftmost water pipe of the bottom layer is led out of the unequal filling retaining wall 3 as the inlet 805 of the water pipe network 8. The rightmost water pipe of the bottom layer is led out of the unequal filling retaining wall 3 as the outlet 806 of the water pipe network. The function of the water pipe network is to circulate water at a certain temperature (around 50℃) within the water pipe network 8. Through heat dissipation, this maintains the filling material within a favorable temperature range, promoting the hydration reaction of the filling material, shortening the hardening time of the filling material in cold regions, and ensuring that the strength of the filling material can reach the design strength requirements in a timely manner. Simultaneously, the water pipe network system is bound to the steel wire rope 5. After the filling material solidifies, the water pipe network 8 itself acts like the reinforcing steel bars in reinforced concrete, providing a framework support and contributing to the overall strength of the filling material.

[0058] The external water supply pipe 9 replenishes water to the constant temperature water tank 10. The constant temperature water tank 10 has an intelligent heater 11, which maintains the water in the constant temperature water tank 10 at a certain temperature (e.g., around 50°C). The warm water in the constant temperature water tank 10 is pumped to the water network 8 through the axial flow water pump 12 via the inlet pipe 13 and the inlet 805. After flowing slowly, the water flows back to the constant temperature water tank 10 through the outlet 806 and the outlet pipe 14.

[0059] After the above equipment is completed, the goaf of the first-stage mine 1 is filled through the filling pipe installed on the top plate of the goaf. During the filling process, the device provides warm water to release and transfer heat to the filling body. At the same time, the heat insulation pad 6 delays the heat dissipation of the filling body during the hydration process, thereby enabling the filling body in the cold area to undergo hydration reaction within a suitable temperature range, improving strength and shortening the time to reach the set strength value.

[0060] The specific mining backfilling steps are as follows: The panel is arranged along the strike of the ore body. The panel is 40m long and 30m wide. The panel is divided into stops and pillars perpendicular to the strike of the ore body. The width of the stops or pillars is 5m. The length of the stop is the same as the length of the panel, which is 40m.

[0061] Mining was carried out along the length of the stope using the drill-and-blast method, with each stope being mined in an alternating pattern. The cross-sectional dimensions of the excavation path were 4×4m. During the mining of the first-stage stope, smooth blasting was used to control the flatness of the roadway walls, with a borehole spacing of 0.6m and a row spacing of 1.0m. After mining was completed, a goaf was formed, and a filling pipe was laid at the highest point of the goaf roof.

[0062] Anchoring devices 4 are installed on the rock mass of the access pillar 2 on both sides of the empty area of ​​the first-step mine stope 1. The anchoring devices 4 are fixed to the rock mass of the access pillar 2 by drilling and anchoring agent. The spacing of the anchoring devices 4 is about 1.8m×1.8m.

[0063] The anchoring device 4 is stitched and bonded to the heat insulation pad 6 around its perimeter. The heat insulation pad 6 is composed of a double-layer fabric and an airtight inner liner, which has good heat preservation and extremely poor heat conduction function. The heat insulation pad 6 is well sealed and can be fixed to the rock wall by the anchoring device 4. The heat insulation pad 6 covers the entire rock wall of the empty area sidewall.

[0064] Anchoring devices 4 are one-to-one corresponding to the sidewalls of the empty area of ​​the first-step stope 1. Anchoring devices 4 have screw tightening facilities. Each one-to-one corresponding anchoring device 4 is connected by two 4mm diameter steel wire ropes 5. The steel wire ropes 5 are prestressed by the screw tightening facilities, so that the steel wire ropes between the anchoring devices 4 are taut and a certain prestress is formed, which is offset by the force of rooting in the rock mass.

[0065] A horizontal water pipe 801 made of thin-walled steel pipe is installed. The horizontal water pipe 801 is fixed to the steel wire rope 5 between the anchoring devices 4 by binding. After the horizontal water pipe 801 is installed, the vertical water pipe 803 is connected by a tee / cross joint to form a uniform 2m×2m heat preservation space 804 between the water pipe network 8 in the open area.

[0066] After the water pipe network 8 in the empty area is formed, the leftmost water pipe of the bottom layer is led out of the unbuilt filling retaining wall 3 as the water inlet 805 of the water pipe network; the rightmost water pipe of the bottom layer is led out of the unbuilt filling retaining wall 3 as the water outlet 806 of the water pipe network; and the air inlet pipe 7 of the heat insulation pad 6 is led out of the unbuilt filling retaining wall 3 as the air inlet of the cavity of the heat insulation pad 6.

[0067] Construct and fill retaining wall 3 to seal off the empty area of ​​the first-stage mine 1.

[0068] The filling process begins. The paste-like filling slurry prepared at the surface filling station is introduced into the empty area of ​​the first-stage stope 1 through the filling pipe. At the same time, the air inlet pipe 7 is opened to inject low-pressure gas (0.3 MPa) into the insulation pad 6. The cavity of the insulation pad 6 expands, forming a thickness of approximately 40 mm. Throughout the filling process of the empty area, the injection of gas into the cavity of the insulation pad 6 is maintained. Its function is to form a heat insulation layer to keep the filling material warm during the hydration process.

[0069] Continue filling until the filling slurry completely submerges the water pipe network 8. Because the water pipe is bound to the steel wire rope 5, its structure is stable and its position in the filling slurry will not move. During the hardening process of the filling body, it will form an integral part with the filling body.

[0070] Forced roof filling is performed on the empty area of ​​the first-step mine 1. In the final stage of roof filling, the air inlet pipe 7 is switched to inject high-pressure gas of 0.8MPa into the heat insulation pad 6. The cavity expansion state is divided into two types. The dense area 601 of the heat insulation pad still maintains a cavity expansion thickness of 40mm, but the expanded area 602 of the heat insulation pad can expand to a greater extent due to the different pressure-sensitive materials, and its expansion thickness can reach up to 600mm. The main purpose of the expanded area 602 of the heat insulation pad is to consider that when the roof is not completely filled during the roof filling, and small empty areas will be formed after the secreted water is drained, the pressure level of the air inlet pipe 7 is switched to inject high-pressure gas of 0.8MPa, so that the expanded area 602 of the heat insulation pad expands further, so that the empty areas formed by the incomplete filling and the secreted water are filled. This process can be maintained until the filling body initially solidifies. The final effect is that the filling body is completely connected to the roof.

[0071] After the filling slurry in the empty area of ​​the first-stage mine stope 1 is fully connected to the roof, the external water supply pipe 9 is opened to replenish the constant temperature water tank 10. The constant temperature water tank 10 is equipped with an intelligent heater 11, which maintains the water in the constant temperature water tank 10 at a certain temperature (around 50℃). The warm water in the constant temperature water tank 10 is pumped to the water network 8 through the axial flow water pump 12 via the inlet pipe 13 and the inlet 805. After flowing slowly, the water flows back to the constant temperature water tank 10 through the outlet 806 and the outlet pipe 14. Through the above process, the warm water releases and transfers heat to the filling body, while the heat insulation pad 6 delays the heat dissipation during the hydration process of the filling body, thereby allowing the filling body in cold regions to undergo hydration reaction within a suitable temperature range, improving strength and shortening the time to reach the set strength value.

[0072] The process of injecting high-pressure gas (0.8 MPa) into the air intake pipe 7 is maintained until the filling material initially sets. At this point, the filling material will stop bleeding water, and its outer contour will be basically formed. The complete contact with the roof will ensure close adhesion between the filling material and the roof rock mass, which is beneficial for future stress transfer and truly enables the filling material to support the roof. After the air intake stops, the opening of the air intake pipe 7 is sealed, keeping the heat insulation pad 6 in an expanded state. In the future, during the mining of the second-stage roadway pillar 2, it can also serve as a blasting buffer layer to mitigate the impact of shock waves on the filling material.

[0073] The constant temperature water tank 10 and its warm water continuously provide insulation and curing for the filling material during the flow of water in the water pipe network 8. This process must continue until the strength of the filling material reaches the set value. The function of the water pipe network is to circulate water at a certain temperature (around 50℃) within the network, dissipating heat to maintain the filling material within a favorable temperature range, thereby promoting the hydration reaction of the filling material, shortening the hardening time of the filling material in cold regions, and ensuring that the strength of the filling material can reach the design strength requirements in a timely manner. At the same time, the water pipe network 8 system is bound to the steel wire rope 5. After the filling material solidifies, the water pipe network itself acts like the steel bars in reinforced concrete, providing a framework support and contributing to the overall strength of the filling material.

[0074] Once the backfill in the first-stage stope 1 has cured to its designed strength, simultaneous mining of the two side pillars 2 can begin. The main reason this mining mode is feasible is that the backfill completely contacts the roof, providing support. Simultaneously, after the rock mass on both sides is transformed into loose ore by drill-and-blast method, the pre-stressed steel wire ropes 5 will drive the anchoring devices 4 and the heat insulation pads 6 to exert overall lateral confining pressure on the backfill. Combined with the water pipe network's "reinforced concrete" frame support, the overall strength of the backfill is significantly increased, ensuring the safety of the two side pillar mining and completely solving the shortcomings of the "three-day interval mining" mode. This allows for the "six work cycles" to be implemented as... Figure 1 The mining sequence has been optimized to a "one-times-per-mining" approach with "four operational cycles," as shown below. Figure 2The mining sequence is optimized; at the same time, considering the shortened curing cycle of the backfill body due to heat preservation, this mining method will greatly improve the efficiency of the mining-backfill cycle and realize efficient access backfill mining in cold regions.

[0075] The combined effect of anchoring device 4 and heat insulation pad 6 in wrapping the sidewall of the backfill will completely eliminate the risk of backfill spalling during the mining process of the access pillar 2, and there will be no backfill mixed into the ore, thus achieving a dilution rate of 0 in the access backfill mining.

[0076] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0077] It should be noted that the above-described embodiments are merely examples. Any embodiments that have the same structure and achieve the same effect as the technical concept within the scope of this application are included in the scope of this application. Furthermore, without departing from the spirit of this application, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, are also included in the scope of this application.

Claims

1. A high-efficiency, non-drainage-reducing backfilling mining method for cold-region mines, characterized in that, Includes the following steps: S1: Panels are arranged along the strike of the ore body, and the panels are divided into stops and pillars within the panel perpendicular to the strike of the ore body. S2: The drilling and blasting method is used to excavate and mine along the length of the stope from the layered connecting roadway of the panel. The mining sequence is one step at a time. After the stope is mined in one step, a goaf is formed. A filling pipe is laid at the highest point of the roof of the goaf. S3: Anchoring devices are installed on the rock mass of the access pillar on both sides of the stope of the first step mine. The anchoring devices correspond one-to-one with the side wall of the stope of the first step mine. Each one-to-one anchoring device is connected by two steel wire ropes. The anchoring device has a screw tightening device. The screw tightening device applies prestress to the steel wire ropes to make the steel wire ropes between the anchoring devices taut. S4: Secure the horizontal water pipes to the steel wire ropes by binding. After the horizontal water pipes are installed, connect the vertical water pipes using multi-connector joints to create an insulated space within the open area, thus forming a water pipe network within the open area. Lead the leftmost water pipe of the bottom layer out through the unbuilt filling retaining wall as the inlet of the water pipe network. Lead the rightmost water pipe of the bottom layer out through the unbuilt filling retaining wall as the outlet of the water pipe network. S5: Construct and fill retaining walls to seal off the empty area of ​​the first-stage mine; S6: The paste filling slurry prepared at the surface filling station begins to enter the empty area of ​​the first-stage stope through the filling pipe; S7: After the filling slurry in the empty area of ​​the first-stage mine has completely reached the top, warm water of 40℃~60℃ is circulated into the water pipe network. S8: Once the void filling body of the first-stage stope has been cured to the design strength, simultaneous mining of the pillars on both sides of the access road begins.

2. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 1, characterized in that, In step S2, smooth blasting is used to control the flatness of the roadway walls during the first-step mining and excavation of the stope. The spacing between the peripheral holes is 0.5 to 0.7 m, and the row spacing is 0.8 to 1.0 m. The cross-sectional dimensions of the excavation approach are 3×3 m to 6×6 m.

3. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 2, characterized in that, The anchoring device is stitched and bonded to the heat insulation pad around its perimeter. The heat insulation pad consists of a double-layered fabric and an airtight inner liner. The heat insulation pad is fixed to the rock wall by the anchoring device, and the heat insulation pad covers the entire rock wall of the empty area. The air inlet pipe of the heat insulation pad leads out to the filling retaining wall that has not yet been built, serving as the air inlet of the heat insulation pad cavity.

4. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 3, characterized in that, The insulation pad consists of a dense zone in the middle and an expanded zone at the edge. The expanded zone continues to expand as the gas pressure increases. At the beginning of filling, the air inlet pipe is opened to inject 0.3 MPa of gas into the insulation pad, causing the insulation pad cavity to expand to a thickness of 30–50 mm. In the final stage of roof connection, the air inlet pipe is switched to inject 0.8 MPa of gas into the insulation pad. The dense zone of the insulation pad maintains its expanded cavity thickness of 30–50 mm, but the expanded zone continues to expand to a thickness of 500–800 mm, filling the voids formed by incomplete filling and seepage. This process continues until the filling material initially solidifies, allowing the filling material to fully connect with the roof.

5. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 1, characterized in that, The panel length is 30-50m and the width is 25-55m. The width of the stope or pillar is 3m-6m, and the stope length is the same as the panel length.

6. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 1, characterized in that, The inlet is connected to an inlet pipe, which is connected to a constant temperature water tank via an axial flow water pump. The outlet is connected to the constant temperature water tank via an outlet pipe.

7. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 6, characterized in that, The constant temperature water tank is equipped with an intelligent heater that can set the temperature, and the constant temperature water tank is also connected to an external water supply pipe.

8. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 1, characterized in that, The anchoring device is fixed to the rock mass of the access pillar by drilling and anchoring agent. The spacing of the anchoring device is 1m×1m~2m×2m.

9. The efficient, non-dilution-reducing backfilling mining method for cold-region mines according to claim 1, characterized in that, The horizontal and vertical water pipes that make up the water pipe network are all made of thin-skinned steel pipes, with specifications ranging from DN25 to DN50.

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