A mining and filling method and equipment for a full negative pressure continuous mining machine for corner coal

Abstract

The present invention discloses a mining and filling method and equipment for a full-negative-pressure continuous miner of corner coal, belonging to the technical field of coal mining; the mining and filling method includes: arranging mining units, mining of block mining chambers, filling of block goafs, mining and filling of a whole group of mining units, and mining and filling of all corner coals, wherein the length of the mining chamber can exceed the length of the continuous miner body by 10m to 50m, effectively reducing the frequency of moving and reversing the working face; the mining and filling equipment includes a continuous miner, a mining support, a filling support, a wind barrier, and a detachable retaining wall, wherein the filling support is additionally provided with a tail isolation device, which has the characteristics of simple assembly and good isolation effect, and the wind barrier can ensure the ventilation safety of the full-negative-pressure airflow passing by the mining chamber; the present invention effectively improves the mining efficiency and filling effect of the working face, thereby improving the resource recovery rate and coal production of the mine.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mining, and in particular relates to a mining and filling method and equipment for a full-negative-pressure continuous miner of marginal coal. Background Art

[0002] Mines commonly use shortwall mining, drift mining, and continuous miner mining (such as Wangeveli mining) to recover marginal coal. These methods have contributed to improving overall resource recovery rates. Due to the small and irregular size of marginal coal areas, their mining faces (i.e., working faces) are mostly shortwalls, making it difficult to achieve the full negative pressure ventilation used in longwall mining. Therefore, most existing marginal coal mining methods still utilize localized fans for ventilation. Compared to longwall mining, marginal coal mining requires the creation of significant coal pillars, resulting in lower recovery rates, with recovery rates typically ranging from 30% to 50%. A few mines have incorporated backfilling into continuous miner mining of marginal coal, leveraging the backfill to replace coal pillars for roof support and the rapid advance of the continuous miner. This has reduced pillar loss to some extent, but due to ventilation safety concerns and issues with the matching mining and backfilling equipment, successful cases of continuous miner backfilling in marginal coal have been limited.

[0003] The 2016 Coal Mine Safety Regulations first stipulated continuous miner mining, and the current 2022 Coal Mine Safety Regulations continue to use these provisions. Two of the regulations stipulate: "Continuous mining must establish full air pressure ventilation before mining can commence," and "The maximum cutting depth of the continuous miner should be determined based on factors such as roof conditions, equipment availability, and coal mining techniques." Following the implementation of the 2016 regulations, the previous method of using localized fans for mining has been eliminated. Currently, continuous miner-based backfill mining technology for marginal coal is largely in the research or trial phase.

[0004] CN 113944464 A discloses a "full-negative-pressure continuous miner mining method for marginal coal." The method employs a "one-in, one-out" ventilation arrangement to achieve full negative-pressure ventilation in both the branch lanes of the mining unit and the mining chamber (i.e., the mining face). While this patented technology meets the full-pressure ventilation requirements of the Coal Mine Safety Regulations, the maximum length of the mining chamber (i.e., the maximum cutting depth of the continuous miner in the mining face) is the length of the continuous miner. When the mining face exceeds the length of the continuous miner, ventilation can only be achieved through diffusion ventilation or local ventilators, and full negative-pressure ventilation cannot be achieved. Furthermore, a shorter mining chamber results in frequent relocation and reversal of the working face, impacting production progress and resulting in lower coal yields. Secondly, in this patented technology, fresh air flows past the continuous miner and the mining shaft during mining. When the stability of the coal seam roof is poor, the air flow may flow through the roof collapse area next to the mining shaft, which violates the provisions of the "Coal Mine Safety Regulations" that "the air intake and return air of the mining working face shall not pass through the roof collapse area". When the coal seam gas concentration is high, it may also cause safety accidents.

[0005] CN 115839240 A discloses a "continuous mining method for high-gas mine corner coal." It employs a "one-in, two-out" ventilation system for laneway layout and a gas extraction method that primarily uses air exhaust and concurrently extracts gas from goaf areas to dilute gas. This achieves full negative pressure ventilation in both the branch lanes of the mining unit and the mining chamber, addressing the problem of gas accumulation or over-limit in the continuous mining working face. However, as with CN 113944464 A, the maximum length of the mining chamber in this patented technology is still the length of the continuous miner, resulting in frequent face shifting and reversing, and airflow may flow through roof collapse areas adjacent to the mining chamber, violating relevant provisions of the Coal Mine Safety Regulations.

[0006] A review of existing patent literature, academic reports, and related books, both domestically and internationally, reveals no effective solution to the short maximum feed depth in full-negative-pressure continuous mining faces. To address the issue of airflow flowing through the roof collapse zone, a few projects have incorporated backfilling into continuous miner mining technology, using backfill to support the coal seam roof and prevent large-scale roof collapse in the goaf. However, determining the optimal roof management, feed depth, and supporting mining and backfilling equipment for continuous miner mining combined with backfilling remains a major technical challenge for scholars and engineers.

[0007] CN 108825237 A discloses "a stratified mining process combining a continuous miner with backfilling for extra-thick coal." This patent combines continuous miner mining and backfilling techniques and applies them to the marginal coal of extra-thick coal seams. This patent provides valuable insights into in-depth research on continuous miner backfilling mining technology, particularly research on roof management after continuous miner mining. However, this patented technology still has some issues and shortcomings: First, the upper strata utilize Wangevilli-style mining, which no longer meets the full-pressure ventilation requirements of the Coal Mine Safety Regulations; second, the length of the mining tunnel (i.e., the cutting depth) is limited to the length of the continuous miner (only 10 meters), resulting in frequent relocation and reversal of the working face; third, the filling pipeline is simply inserted into the goaf of the working face for filling, without explaining how the mining and backfilling equipment should be coordinated. This makes this patented technology unsuitable for guiding on-site construction operations.

[0008] CN 104500070 A discloses a "continuous coal miner paste filling mining method." The method involves placing the continuous miner mining and paste filling pipelines in the branch lanes on either side of the main and auxiliary lanes, respectively. Parallel mining and filling operations are applied to "three-down" compressed coal mining. Because the patent application was filed in 2015, and the "Coal Mine Safety Regulations" (2016 edition) had not yet been implemented, the patented technology currently suffers from the following problems and shortcomings: First, the continuous miner performs a left-right mining operation (similar to the Wangevilli method) and relies on local ventilators, which no longer meets the full-pressure ventilation requirements of the "Coal Mine Safety Regulations." Second, the mining tunnel is 11 meters long, resulting in frequent face relocation and reversal. Third, the mining and filling operations are arranged on either side of the main and auxiliary lanes, with the two systems operating independently. No mention is made of supporting mining and filling equipment technology.

[0009] CN 111535844 A discloses a "coal-pillar-free mining equipment system and method for gob-side entry-retention in hard roofs." The patent describes a system comprising a base, roof beam, support pillars, filling baffles, and fixed plates. While coal mining is performed within the mining tunnel, filling operations are performed in the entry-retention area on one side of the gob. Because gob-side entry-retention in coal-pillar-free mining is a type of longwall mining system, it requires a dense distribution of several joint supports along the working face to support the working face roof and move the mining and transportation equipment. However, continuous miner-filling mining technology only requires a few supports to support the working face roof, eliminating the need to move the mining and transportation equipment. Therefore, the mining equipment system and method disclosed in this patent are not suitable for continuous miner-filling mining processes. Summary of the Invention

[0010] The present invention overcomes the shortcomings of the existing technology and proposes a mining and filling method and equipment for a full-negative-pressure continuous miner of marginal coal; it solves the problems in the current filling mining technology of the continuous miner of marginal coal, such as the short mining tunnel length, the inability to ensure ventilation safety due to the airflow passing by the deep mining tunnel, the unreasonable matching of mining and filling equipment, and the low resource recovery rate and coal output.

[0011] The present invention is achieved through the following technical solutions:

[0012] A method for mining and filling corner coal using a full negative pressure continuous miner, comprising the following steps:

[0013] Step 1: Arrange the mining unit: The mining unit includes the mining branch roadway, the filling branch roadway and the internal coal pillars between them; the internal coal pillars are divided into multiple blocks, each block includes multiple deep mining shafts; isolation coal pillars and unit cross-sections are set between adjacent blocks, and temporary closed walls are set in the unit cross-sections;

[0014] Step 2: Mining the innermost block: First, set up mining supports and filling supports in front of the two end branch tunnels of the innermost deep mining cave in the innermost block, and then use a continuous miner to mine the innermost deep mining cave. After mining is completed, move the mining supports and filling supports to the two end branch tunnels of the innermost deep mining cave, and hang wind barriers between the mining supports and filling supports. Then, mine the next adjacent deep mining cave. In this way, retreat mining is carried out in sequence until the last deep mining cave in the innermost block is mined.

[0015] Step 3: Filling the goaf of the innermost block: After mining the last deep mining tunnel in the innermost block, remove the wind barrier, move the mining support and the filling support to the branch tunnel openings at both ends of the isolation coal pillar between the innermost block and the next block, and then open the temporary closed wall in the unit cross-section between the two blocks to form a ventilation system between the mining unit branch tunnel and the next block; then set a detachable retaining wall at the isolation coal pillar position in the mining branch tunnel, and at the same time start the tail isolation device of the filling support in the filling branch tunnel to block the goaf of the innermost block; then fill the goaf;

[0016] Step 4: Mining and filling the entire mining unit: Mining and filling the remaining blocks in the mining unit from the inside to the outside in accordance with steps 2 and 3 until all blocks in the entire mining unit are mined and filled;

[0017] Step 5: Mining and filling all the corner coal: According to steps 2 to 4, adjacent mining units are mined and filled from the inside to the outside and alternately from left to right until all the corner coal areas are mined and filled.

[0018] Preferably, the length of the deep mining shaft is 10m to 50m.

[0019] Preferably, the width of the deep mining tunnel is the mining width of the continuous miner, the width of each block is 4 to 6 mining tunnels; the width of the isolation coal pillar is 1 to 2 mining tunnels, and the transverse width of the unit is 1 mining tunnel width.

[0020] Preferably, in step three, the filling of the goaf is performed by extending the filling pipe along the top plate of the filling branch tunnel through the filling hole reserved at the upper end of the tail isolation device of the filling support into the goaf, opening the gate valve on the filling pipe for filling until the filling body fills the goaf of the innermost block.

[0021] Preferably, in step three, the four sides of the detachable retaining wall are inserted into the surrounding rock of the mining branch tunnel, and the mining side of the detachable retaining wall is tightly attached with an isolation membrane to seal the mining branch tunnel.

[0022] The mining and filling equipment used for the described method of full-negative-pressure continuous mining and filling of corner coal includes a continuous miner, a mining support, a filling support, a wind barrier and a detachable retaining wall; the mining support is arranged in the mining branch tunnel at one end of the deep mining tunnel immediately following the continuous miner, and the filling support is arranged in the filling branch tunnel at the other end of the deep mining tunnel; during mining, the wind barrier is hung across the goaf between the mining support and the filling support, and during filling, the filling support and the detachable retaining wall are arranged in the branch tunnels at both ends of the isolation coal pillar to seal the goaf of the entire block.

[0023] Furthermore, the filling bracket includes a bracket body and a tail isolation device arranged on the bracket body; the bracket body includes a top beam, a base and a pillar; the tail isolation device includes a tail beam, a tail seat, an isolation plate, an inclined pillar and a film roller; the tail of the top beam is connected to the tail beam, and the tail of the base is connected to the tail seat, and the tail beam and the tail seat are still supported by the pillar; the tail of the tail seat is connected to the isolation plate, and the base and the isolation plate are connected with an inclined pillar, and a film roller is suspended under the tail of the top beam, and the film roller is equipped with an isolation film.

[0024] Furthermore, the isolation plate is a combined plate that can be combined and spliced ​​upward and left and right; when the filling bracket seals the goaf, first rotate the membrane roller to pull the isolation membrane to the bottom plate of the goaf side branch tunnel of the isolation plate, and then combine and splice the isolation plates to close the filling branch tunnel.

[0025] The beneficial effects of the present invention compared to the prior art are:

[0026] (1) The mining and filling method provided by the present invention breaks through the technical bottleneck of the existing continuous miner mining technology in which the maximum cutting depth (i.e., the length of the mining tunnel) during mining does not exceed the length of the continuous miner body. The deep mining tunnel length can reach 10m to 50m. The increased mining tunnel length can not only ensure full negative pressure ventilation of the working face, but also avoid safety problems such as roof collapse. At the same time, it can reduce the frequency of working face relocation and face collapse, promote production progress, and thus increase coal production. Taking mining safety into consideration, the present invention limits the length of the deep mining tunnel to 10m to 50m. However, under the premise of good coal seam roof stability, sufficient filling strength, and sufficient coal pillars at the engineering site, the maximum mining tunnel length can be even longer.

[0027] (2) The mining and filling method and equipment provided by the present invention innovatively introduce wind barriers into the full negative pressure air path of the continuous mining machine. The wind barriers are reasonably hung in the goaf of the previous mining cave of the positive mining cave, so that full negative pressure ventilation can be achieved on the working face during the deep mining cave. Since the wind barriers are close to the positive mining cave (the distance is usually less than the maximum control distance), although they are located in the goaf, the roof of the goaf where the wind barriers are located will not collapse in a short time. Therefore, the wind barriers can smoothly guide the full negative pressure airflow in the deep mining cave, improve the ventilation efficiency, and avoid the airflow from flowing through the roof collapse area, meeting the relevant provisions of the "Coal Mine Safety Regulations". At the same time, the wind barriers can also isolate the gas and toxic and harmful gases in the goaf on the other side of the wind barriers, effectively solving the ventilation safety problem of full negative pressure airflow passing by the deep mining cave.

[0028] (3) The mining and filling method and equipment provided by the present invention innovatively integrate the filling support and detachable retaining wall into the continuous mining process. During mining and filling, each device performs its own function and cooperates closely, effectively improving the recovery efficiency and filling effect of the working face. The mining support is arranged in the mining branch tunnel at one end of the deep mining tunnel right after the continuous miner. It is responsible for supporting the roof of the branch tunnel behind the mining tunnel, which can not only ensure the stability of the roof caused by mining at the rear of the mining tunnel, but also ensure the safety of personnel operating the continuous miner and ancillary equipment under the mining support; the filling support is arranged in the filling branch tunnel at the other end of the deep mining tunnel, which can not only assist the mining support in jointly supporting the roof of the branch tunnels at both ends of the deep mining tunnel, but also ensure the safety of personnel operating the filling device under the filling support during filling; during mining, the wind barrier is hung across the goaf between the mining support and the filling support, which can effectively guide the wind flow during mining of the deep mining tunnel; during filling, the filling support and the detachable retaining wall are set in the branch tunnels at both ends of the isolation coal pillar, which can effectively seal the goaf of the entire block to prevent leakage and slurry leakage during the filling process. At the same time, the filling support and the detachable retaining wall can be reused, reducing the cost of goaf sealing materials.

[0029] (4) The mining and filling method provided by the present invention divides each mining unit into multiple blocks, and performs mining and filling operations sequentially from the inside out. During operation, the coal seam roof within the block is supported by filling bodies, isolation coal pillars, inter-unit coal pillars, mining supports, filling supports, and support materials across the top of the branch tunnel. This is beneficial to the roof management of the goaf after deep mining, and avoids large-scale roof collapse in the goaf within the block, as well as safety issues such as roof pressure and gas influx caused by roof collapse. Compared with the existing full negative pressure continuous mining machine mining technology, the addition of filling bodies and filling supports can reduce the size of isolation coal pillars and inter-unit coal pillars, thereby improving the resource recovery rate of the working face, which can reach 50% to 70%.

[0030] (5) The mining and filling equipment provided by the present invention also innovatively proposes a new type of filling support, which is modified from an ordinary support body with a tail isolation device added. It takes into account the supporting ability of the ordinary support on the coal seam roof and the sealing ability of the isolation device on the filling area. It has the characteristics of simple assembly, low investment and good isolation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the planar layout of the mining and filling method of the full negative pressure continuous miner for corner coal according to the present invention;

[0032] Figure 2 This is a schematic diagram of the mining arrangement of block ① within the mining unit of the present invention;

[0033] Figure 3 This is a schematic diagram of the filling arrangement of the goaf in block ① within the mining unit according to the present invention;

[0034] Figure 4 This is a schematic diagram of the modified structure of the filling bracket according to the present invention;

[0035] In the figure: 1—transport chute; 2—return air chute; 3—mining branch lane; 4—filling branch lane; 5—inter-unit coal pillar; 6—adjusting air door; 7—sealed wall; 8—deep mining cavern; 9—isolation coal pillar; 10—unit cross-section; 11—temporary closed wall; 12—goaf; 13—fresh air flow; 14—exhaust air flow; 15—mining support; 16—filling support; 161—tail beam; 162—tail stock; 163—isolation plate; 164—inclined support; 165—membrane roller; 166—top beam; 167—base; 168—support; 17—continuous miner; 18—wind barrier; 19—detachable retaining wall; 20—isolation membrane; 21—filling pipe; 22—filling body. DETAILED DESCRIPTION

[0036] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail with reference to the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. The technical solutions of the present invention will be described in detail below with reference to the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0037] like Figures 1 to 3 As shown, this embodiment provides a method for mining and filling corner coal with a full negative pressure continuous miner, comprising the following five steps:

[0038] Step 1: Arrangement of mining units: Figure 1As shown, two drift tunnels, a transport drift 1 and a return air drift 2, are arranged along the corner coal area. Multiple groups of mining units are then arranged sequentially from the inside out along both sides of the drift tunnel (this embodiment uses a group of mining units on the right side of the drift tunnel as an example). A mining unit consists of a mining branch tunnel 3, a filling branch tunnel 4, and their internal coal pillars. The interior of the mining unit is divided into multiple blocks, such as ①, ②, ③, etc. Each block has 4 to 6 mining tunnels, each of which is a deep mining tunnel 8. Isolating coal pillars 9 and unit cross sections 10 are installed between adjacent blocks, with temporary closed walls 11 installed in the unit cross sections 10. During on-site construction, the drift tunnels should be arranged as close to the higher level of the corner coal area as possible, so that the mining unit branch tunnels are relatively low to facilitate the self-flow of the filling material 22 during filling. The two drift tunnels are connected to the two branch tunnels of each mining unit, and adjustable dampers 6 and closed walls 7 are reasonably set at the intersection to form a full negative pressure ventilation system between the drift tunnel and the branch tunnels of each mining unit.

[0039] Furthermore, in step 1, the length of the deep mining cave 8 is 10m to 50m, and the width of the deep mining cave 8 is the mining width of the continuous mining machine 17. During on-site construction, the angle between the drift roadway and the mining unit branch roadway is 50° to 70°, and the angle between the deep mining cave 8 and the mining branch roadway 3 is 40° to 60°. The two mining unit branch roadways may not be arranged in parallel, but the angle between the branch roadway and the drift roadway should be in the range of 50° to 70°, and the net width of the coal pillar inside the mining unit shall not be greater than the cosine value of the angle between the deep mining cave 8 and the mining branch roadway 3 multiplied by the maximum length of the deep mining cave 8; the width of the deep mining cave 8 should be reasonably determined according to the specifications of the continuous mining machine 17, and be the width of one cut of the continuous mining machine 17.

[0040] Furthermore, in step one, the width of each block is 4 to 6 mining tunnels, the width of the isolation coal pillar 9 is 1 to 2 mining tunnels, and the width of the unit cross section 10 is 1 mining tunnel; an inter-unit coal pillar 5 is provided between two adjacent groups of mining units, and the width of the inter-unit coal pillar 5 is 10m to 15m. During on-site construction, when the internal blocks of the mining unit are divided, the width of each block should be reasonably determined based on factors such as the width of the isolation coal pillar 9 and the inter-unit coal pillar 5, the length of the mining tunnels within the block, the support strength of the mining unit branch tunnels and the top of the unit cross section 10, etc. It is usually appropriate to take 4 to 6 mining tunnels. If the width is too small, there will be too many block divisions and frequent alternation of mining and filling processes. If the width is too large, it will make it difficult to manage the roof of the goaf after the mining tunnels in the block. The main function of the isolation coal pillar 9 is to carry out effective work within the block. To effectively seal the coal seam, its width should be reasonably determined based on factors such as the thickness of the coal seam (specifically, the mining height of the mining tunnel), coal seam stability, and density. In projects encountering medium-thick coal seams with good stability and density, the isolation pillar 9 should be one mining tunnel width, while in projects encountering coal seams with poor stability and density or thick coal seams, the isolation pillar 9 should be two mining tunnel widths. The main function of the unit cross-section 10 is to ensure the formation of a ventilation system during mining in each block, so it does not need to be too wide. When arranging the mining unit branch tunnels, a continuous miner 17 can be used to dig a cut in advance, that is, the width of the unit cross-section 10 should be one mining tunnel width. If the coal seam roof has structural or other special geological conditions and the mine pressure is severe at the project site, the size of the inter-unit coal pillars 5 and the isolation coal pillars 9 should be increased to ensure the safety of the project construction.

[0041] Step 2: Mining and re-mining of Block ①: Figure 2 As shown, first, mining supports 15 and filling supports 16 are respectively set in front of the two end branch tunnels of the innermost deep mining shaft 8 in block ①, and then the continuous mining machine 17 is used to mine the innermost deep mining shaft 8; after the innermost deep mining shaft 8 is mined, the mining supports 15 and filling supports 16 are respectively moved to the two end branch tunnels of the innermost deep mining shaft 8, and wind barriers 18 are hung between the mining supports 15 and the filling supports 16, and then the next connected deep mining shaft 8 is mined; in this way, backward mining is carried out in sequence until the last deep mining shaft 8 in block ① is mined. During on-site construction, the number of mining supports 15 and filling supports 16 should be reasonably determined based on factors such as roof pressure and branch tunnel width, and usually no less than two. During mining, the distance between the front ends of the mining supports 15 and filling supports 16 and the empty wall of the deep mining tunnel 8 being mined is 1m to 2m; the mining supports 15 are used in conjunction with the continuous mining machine 17, which is responsible for supporting the branch tunnel roof behind the deep mining tunnel 8 being mined, and the filling supports 16 are mainly used in conjunction with the filling pipe 21, and assist the mining supports 15 in jointly supporting the branch tunnel roofs at both ends of the deep mining tunnel 8; the wind barrier 18 is hung above the nearest mining support 15 and filling support 16 at both ends of the deep mining tunnel 8, and crosses the goaf of the deep mining tunnel 8 before the deep mining tunnel 8 being mined, and is responsible for guiding the full negative pressure airflow in the deep mining tunnel 8; see Figure 2The new air flow 13 flows from the mining branch tunnel 3 to the area between the deep mining tunnel 8 and the wind barrier 18, forming the exhausted air flow 14 and then flowing to the filling branch tunnel 4.

[0042] Step 3: Filling the goaf of block ①: Figure 3 and Figure 4 As shown, after the last deep mining tunnel 8 in block ① is mined, the wind barrier 18 is removed, and the mining support 15 and the filling support 16 are moved to the branch tunnels at both ends of the isolation coal pillar 9 between blocks ① and ②, and then the temporary closed wall 11 in the innermost unit cross 10 of block ② is opened to form a ventilation system for the mining unit branch tunnel and block ②. Figure 3 , the new air flow 13 passes through the unit cross-section 10 to form the exhausted air flow 14 and then flows to the filling branch tunnel 4; then a removable retaining wall 19 is set at the position of the isolation coal pillar 9 in the mining branch tunnel 3, and at the same time, the tail isolation device of the filling support 16 is started in the filling branch tunnel 4 to seal the goaf 12 of block ①; then the filling pipe 21 is extended into the goaf 12 along the top plate of the filling branch tunnel 4 through the filling hole reserved at the upper end of the isolation plate 163, and the gate valve on the filling pipe 21 is opened for filling until the filling body 22 fills the goaf of block ①. During on-site construction, before sealing the goaf 12 of the block, the temporary closed wall 11 in the unit cross-section 10 between the next block and the next block should be opened first to form a ventilation system between the mining unit branch tunnel and the next block connected to the block before sealing the goaf 12 of the block; when the staff sets up the removable retaining wall 19 and starts the tail isolation device, they should operate within 6m of the ventilation system line to meet the diffusion ventilation requirements. At the same time, gas monitoring at the personnel location should be strengthened to prevent poisoning and suffocation of personnel; in order to meet the filling needs of the filling pipe 21, the filling pipe 21 in the filling branch tunnel 4 should be reasonably equipped with a series of supporting regulating valves, stop valves, material distribution valves, reducers and other components. After each block is filled, the filling pipe 21 should be cleaned as necessary.

[0043] Furthermore, in step three, the perimeter of the removable retaining wall 19 should be inserted into the surrounding rock of the mining branch tunnel 3, and the mined side of the removable retaining wall 19 should be closely attached to an isolation membrane 20 to seal the mining branch tunnel 3. During on-site construction, the removable retaining wall 19 can be assembled by hand or purchased as a ready-made product, as long as it can effectively seal and remove the mining branch tunnel 3. The isolation plate 163 of the filling support 16 and the mined side of the removable retaining wall 19 should both be closely attached to a layer of isolation membrane 20. The isolation membrane 20 should seal the entire branch tunnel section. If a single layer is insufficient to seal the entire branch tunnel section, multiple layers of overlapping membranes can be used.

[0044] Step 4: Mining and filling of the entire mining unit: After the filling body 22 in block ① is basically solidified, the detachable retaining wall 19 is removed, and the tail isolation device of the filling support 16 is retracted. Then, the mining support 15 and the filling support 16 are respectively moved to the branch tunnels at both ends of the innermost unit cross 10 of block ②. The wind barrier 18 is hung in the same way as in step 2, and the deep mining shafts 8 in block ② are mined in a backward manner in sequence until the last deep mining shaft 8 in block ② is mined. An isolation coal pillar 9 is left and the temporary closed wall 11 in the innermost unit cross 10 of block ③ is opened to form a ventilation system between the mining unit branch tunnel and block ③. Then, the goaf of block ② is filled in the same way as in step 3. In this way, the remaining blocks in the mining unit are mined and filled in turn from the inside to the outside in the same way as in steps 2 and 3 until all the blocks in the entire mining unit are mined and filled. During on-site construction, the removable retaining wall 19 can be removed and the tail isolation device can be retracted only after the solidification strength of the filling body 22 in the block reaches 70% of the design strength and is not squeezed, deformed or flowed; after removal and retraction, the isolation membrane 20 remains attached to the filling body 22, and try not to destroy the closed structure of the isolation membrane 20.

[0045] Step 5: Mining and filling all corner coal: After completing one mining unit, arrange the next set of mining unit branch lanes from the inside out, alternating left and right. Continue mining and filling adjacent mining units in the same manner as Steps 2 through 4, and repeat this process until all corner coal areas are mined and filled. During on-site construction, after all mining units have been mined and filled, and while ensuring roof and ventilation safety, two drift lanes can be used as mining unit branch lanes. Using a similar approach as Steps 2 through 4, these two drift lanes and their internal coal pillars can be mined and filled appropriately to further improve the recovery rate of corner coal resources.

[0046] Furthermore, the tops of the drift roadway, mining branch roadway 3, filling branch roadway 4, and unit cross section 10 are all provided with support materials to stabilize the coal seam roof. No support materials are required on the tops of the deep mining chambers 8 within each mining unit. During on-site construction, the support materials for both sides of the aforementioned roadways should be reasonably determined based on factors such as roof pressure, mining height, and coal seam stability. Under the premise of ensuring the safety of roadway construction, the mining sides (i.e., the side of the mining chamber arranged within the mining unit) of the mining branch roadway 3 and the filling branch roadway 4, as well as the sides of the unit cross section 10, should not be provided with support materials other than protective nets as much as possible to improve the mining progress.

[0047] Based on the aforementioned method for mining and filling a corner coal continuous miner with full negative pressure, this embodiment further provides a mining and filling device for a corner coal continuous miner with full negative pressure, including a continuous miner 17, a mining support 15, a filling support 16, a wind barrier 18, and a removable retaining wall 19. The filling support 16 and the removable retaining wall 19 are integrated into the continuous miner mining process, so that during mining and filling, each device performs its respective functions while working closely together, effectively improving the recovery efficiency and filling effect of the working face. The filling support 16 is modified from an ordinary support body with a tail isolation device added. It takes into account both the ordinary support's ability to support the coal seam roof and the isolation device's ability to seal the filling area. It has the characteristics of simple assembly, low investment, and good isolation effect.

[0048] During on-site construction, the mining support 15 is arranged in the mining branch tunnel 3 at one end of the deep mining tunnel 8, following the continuous mining machine 17, and is responsible for supporting the roof of the branch tunnel behind the mining tunnel, which can not only ensure the stability of the roof caused by mining at the rear of the mining tunnel, but also ensure the safety of personnel operating the continuous mining machine 17 and ancillary equipment under the mining support 15; the filling support 16 is arranged in the filling branch tunnel 4 at the other end of the deep mining tunnel 8, which can not only assist the mining support 15 in jointly supporting the roof of the branch tunnels at both ends of the deep mining tunnel 8, but also ensure the safety of personnel operating the filling support 16 under the filling support 16 during filling. Control the safety of the filling pipe 21 and its supporting devices; during mining, the wind barrier 18 crosses the goaf 12 after the deep mining shaft 8 is mined and is hung between the mining support 15 and the filling support 16, which can effectively guide the wind flow during the deep mining shaft mining; during filling, the filling support 16 and the detachable retaining wall 19 are set in the branch tunnels at both ends of the isolation coal pillar 9 to seal the goaf 12 of the entire block, preventing slurry leakage and slurry leakage during the filling process. At the same time, the filling support 16 and the detachable retaining wall 19 can be reused, reducing the cost of goaf sealing materials. It should be noted that in addition to the aforementioned mining and filling equipment, the project site should also include other necessary transportation, support, loading and unloading and other supporting equipment.

[0049] Further, such as Figure 4As shown, the filling bracket 16 includes a common bracket body and a tail isolation device arranged on the bracket body; the bracket body includes a top beam 166, a base 167 and a support 168; the tail isolation device of the filling bracket 16 includes a tail beam 161, a tail seat 162, an isolation plate 163, an inclined support 164, and a film roller 165. When the ordinary bracket top beam 166 is modified, a tail beam 161 is added to the tail of the ordinary bracket top beam 166, and a tail seat 162 is added to the tail of the base 167. The tail beam 161 and the tail seat 162 are still supported by the support 168. The tail of the tail seat 162 is provided with an isolation plate 163, and the isolation plate 164 is provided. One side of 63 is hinged to the tail of the tailstock 162; the isolation plate 163 is a combined plate that can be spliced ​​upward and left and right, and a membrane roller 165 is suspended under the tail of the top beam 166, and an isolation membrane 20 is installed on the membrane roller 165; when the filling bracket 16 seals the goaf, first rotate the membrane roller 165 to pull the isolation membrane 20 to the bottom plate of the goaf side branch tunnel of the isolation plate 163, and then rotate the isolation plate 163 into an upright state, and then connect the inclined support 164 between the tail of the base 167 and the isolation plate 163 to support and fix the isolation plate 163, and use the isolation plate 163 to close the filling branch tunnel 4. During on-site reconstruction, the widths of the tail beam 161 and the top beam 166 need to match, and they are connected through bearings; the widths of the tail seat 162 and the base 167 need to match, and they are connected through bearings; the isolation plate 163 is a composite plate composed of multiple plates spliced ​​together, and the plates are extended or retracted by cableways. A filling hole needs to be reserved at the upper end of the isolation plate 163, and the hole diameter needs to match the filling pipe 21; the two ends of the inclined support 164 are connected to the base 167 and the isolation plate 163 through bearings.

[0050] The mining and backfilling method and equipment proposed in this embodiment were applied to the backfilling mining of marginal coal in a certain mine. The average thickness of the coal seam in this marginal coal area is 4.2 meters, the average burial depth is 240 meters, and the coal seam roof is relatively stable limestone. The specifications of the main mining and backfilling equipment used are as follows: The continuous miner 17 is an EML340 continuous miner with overall dimensions of 11 meters by 3.3 meters by 2.05 meters, a mining height range of 2.7 to 5.5 meters, and a mining width of 3.3 meters. The mining supports 15 are two XZ7000 / 24.5 / 46 crawler hydraulic supports. The backfilling supports 16 are two existing ZY6000 / 22 / 45 hydraulic supports modified with tail isolation devices. The windbreak 18 is a 4-meter-wide canvas windbreak. The removable retaining wall 19 is welded from steel plates and channel steel, with a maximum blockage dimension of 5.5 meters by 5.0 meters after extension.

[0051] The corresponding layout specifications of the mining and filling method are as follows: the cross-sectional dimensions of the transport drift 1 and the return air drift 2 are both 4.5m×3.5m, and the top and two sides are supported by anchor mesh; the cross-sectional dimensions of the mining branch roadway 3 and the filling branch roadway 4 are both 4.8m×4.2m, and the top and non-mining sides are supported by anchor rods + metal mesh, and the mining sides are supported by metal mesh; the angle between the drift roadway and the mining unit branch roadway is 60°, the net width of the coal pillar inside the mining unit is 30m, and the angle between the deep mining shaft 8 and the mining branch roadway 3 is 45°; the length of the deep mining shaft 8 is 42.4m (equal to 30 / cos45°). The width is 3.3m (equal to the mining width of continuous miner 17), the height is 4.2m (equal to the thickness of the coal seam), and no support materials are set in the deep mining shaft 8; the width of each block inside the mining unit is 16.5m (equal to the width of 5 mining shafts), the width of the isolation coal pillar 9 is 3.3m (the width of 1 mining shaft), and the width of the coal pillar 5 between units is 12m; the width of the unit cross section 10 is 3.3m (the width of 1 mining shaft) and the height is 4.2m (equal to the thickness of the coal seam), the cross section top is supported by anchor rods + metal mesh, and the two sides are supported by metal mesh; the filling method of the goaf is paste filling, and the compressive strength of the filling after solidification is 4MPa.

[0052] After on-site verification at the mine, the recovery rate of corner coal resources in the working face of the mine is about 65%, the monthly coal production reaches 35,000 tons, and the estimated annual coal production is about 400,000 tons, which exceeds the normal level of the industry (300,000 tons / year). No roof collapse accidents or ventilation safety accidents occurred during mining, and the safety is relatively good. There was basically no leakage or slurry running during filling, and the filling effect was good. The mining and filling method and equipment proposed in this patent have achieved good economic and social benefits for the mine, proving the feasibility and rationality of the technical solution of the present invention.

[0053] Furthermore, the mining and filling method and equipment of the full-negative-pressure continuous miner for corner coal provided by the present invention can replace the continuous miner 17 with an ordinary tunneling machine or coal shear, and its mining and filling method is still applicable; its goaf filling is not only suitable for paste filling, but also for slurry filling.

[0054] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be considered that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the present invention, which should be regarded as belonging to the scope of patent protection determined by the submitted claims of the present invention.

Claims

1. A method for mining and filling corner coal with a full negative pressure continuous miner, characterized in that: The following steps are involved: Step 1: Arrange the mining unit: the mining unit includes a mining branch tunnel (3), a filling branch tunnel (4) and the internal coal pillars therebetween; the internal coal pillars are divided into a plurality of blocks, each block including a plurality of deep mining chambers (8); isolation coal pillars (9) and unit cross sections (10) are provided between adjacent blocks, and a temporary closed wall (11) is provided in the unit cross section (10); Step 2, mining and re-mining of the innermost block: first, mining supports (15) and filling supports (16) are respectively set in front of the two end branch tunnels of the innermost deep mining cave (8) in the innermost block, and then the innermost deep mining cave (8) is mined by a continuous mining machine (17). After the mining is completed, the mining supports (15) and the filling supports (16) are respectively moved to the two end branch tunnels of the innermost deep mining cave (8), and a wind barrier (18) is hung between the mining supports (15) and the filling supports (16), and then the next adjacent deep mining cave (8) is mined; in this way, the mining is carried out in a backward manner until the last deep mining cave (8) in the innermost block is mined; Step 3, filling the goaf of the innermost block: after the last deep mining tunnel (8) in the innermost block is mined, the wind barrier (18) is removed, and the mining support (15) and the filling support (16) are respectively moved to the branch tunnel openings at both ends of the isolation coal pillar (9) between the innermost block and the next block, and then the temporary closed wall (11) in the unit cross-section (10) between the two blocks is opened to form a ventilation system for the mining unit branch tunnel and the next block; then a detachable retaining wall (19) is set at the position of the isolation coal pillar (9) in the mining branch tunnel (3), and at the same time, the tail isolation device of the filling support (16) is started in the filling branch tunnel (4) to block the goaf (12) of the innermost block; then the goaf (12) is filled; Step 4: Mining and filling the entire mining unit: Mining and filling the remaining blocks in the mining unit from the inside to the outside in accordance with steps 2 and 3 until all blocks in the entire mining unit are mined and filled; Step 5: Mining and filling all the corner coal: According to steps 2 to 4, adjacent mining units are mined and filled from the inside to the outside and alternately from left to right until all the corner coal areas are mined and filled.

2. A method for mining and filling corner coal with a full negative pressure continuous miner according to claim 1, characterized in that: The length of the deep mining tunnel (8) is 10m to 50m.

3. The method for mining and filling corner coal with a full negative pressure continuous miner according to claim 2, characterized in that: The width of the deep mining tunnel (8) is the mining width of the continuous mining machine (17), the width of each block is 4 to 6 mining tunnels, the width of the isolation coal pillar (9) is 1 to 2 mining tunnels, and the width of the unit cross section (10) is 1 mining tunnel.

4. The method for mining and filling corner coal with a full negative pressure continuous miner according to claim 1, characterized in that: In step three, the goaf (12) is filled by extending the filling pipe (21) along the top plate of the filling branch tunnel (4) through the filling hole reserved at the upper end of the tail isolation device of the filling support (16) into the goaf (12), and opening the gate valve on the filling pipe (21) to fill until the filling body (22) fills the goaf (12) of the innermost block.

5. The method for mining and filling corner coal with a full negative pressure continuous miner according to claim 1, characterized in that: In the step 3, the detachable retaining wall (19) is inserted into the surrounding rock of the mining branch tunnel (3) on all sides, and the mining side of the detachable retaining wall (19) is tightly attached with an isolation membrane (20) to seal the mining branch tunnel (3).

6. The mining and filling equipment used in the mining and filling method of a full negative pressure continuous miner for corner coal according to any one of claims 1 to 5, characterized in that: The invention comprises a continuous mining machine (17), a mining support (15), a filling support (16), a wind barrier (18) and a detachable retaining wall (19); the mining support (15) is arranged in a mining branch tunnel (3) at one end of a deep mining tunnel (8) immediately following the continuous mining machine (17); the filling support (16) is arranged in a filling branch tunnel (4) at the other end of the deep mining tunnel (8); during mining, the wind barrier (18) crosses the goaf (12) and is hung between the mining support (15) and the filling support (16); during filling, the filling support (16) and the detachable retaining wall (19) are arranged in the branch tunnels at both ends of the isolation coal pillar (9) to seal the goaf (12) of the entire block.

7. The mining and filling equipment for a full negative pressure continuous miner of corner coal according to claim 6, characterized in that: The filling bracket (16) includes a bracket body and a tail isolation device arranged on the bracket body; the bracket body includes a top beam (166), a base (167) and a support (168); the tail isolation device includes a tail beam (161), a tail seat (162), an isolation plate (163), an inclined support (164) and a film roller (165); the tail of the top beam (166) is connected to the tail beam (161), and the tail of the base (167) is connected to the tail seat (162), and the tail beam (161) and the tail seat (162) are still supported by the support (168); the tail of the tail seat (162) is connected to the isolation plate (163), and the inclined support (164) is connected between the base (167) and the isolation plate (163); a film roller (165) is suspended below the tail of the top beam (166), and an isolation film (20) is installed on the film roller (165).

8. The mining and filling equipment for a full negative pressure continuous miner of corner coal according to claim 7, characterized in that: The isolation plate (163) is a combined plate that can be combined and spliced ​​upward and leftward and rightward; when the filling support (16) blocks the goaf (12), the membrane roller (165) is first rotated to pull the isolation membrane (20) onto the bottom plate of the goaf side branch tunnel of the isolation plate (163), and then the isolation plate (163) is combined and spliced ​​to close the filling branch tunnel (4).

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