A method for advanced replacement of coal pillars in tunnels by retreating continuous excavation and filling

Abstract

The purpose of the present invention is to provide a method for the advanced replacement of coal pillars in the tunnel by retreating continuous excavation and filling, which belongs to the technical field of coal mine excavation and filling. The present invention gives full play to the characteristics of the flexibility of excavation and support equipment and the simplicity and reliability of the filling equipment set, forming an integrated excavation and filling process and system with retreat between stages, skipping mining within stages and timely filling. Through the process of the present invention, on the one hand, advanced replacement can be achieved, that is, the coal pillars in the tunnel are recovered and filled before the comprehensive mining face is mined, ensuring the safety and efficiency of the mining work. On the other hand, the excavation and coal pillar recovery processes are separated, the process is simplified, and the workload of filling preparation is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine excavation and filling, and particularly relates to a backward continuous excavation and filling advance replacement method for coal pillars in a roadway. Background Art

[0002] Most underground coal mines in my country use a comprehensive mechanized mining method. Due to the mining process, equipment, and tunnel system layout, coal pillars are left between the two fully mechanized working faces. These pillars are difficult to recover, resulting in significant resource waste. The main reasons for this difficulty are: First, the current comprehensive mechanized mining process and equipment cannot recover the pillars; second, tunneling equipment is constrained by the tunneling process, tunnel system layout, and production efficiency, safety, filling efficiency, and cost, making conventional recovery methods uneconomical and unreasonable. Summary of the Invention

[0003] In response to the above problems, the present invention discloses a method for advanced replacement of coal pillars in tunnels with backward continuous excavation and filling, which fully utilizes the mobility and flexibility of the excavation equipment and the simplicity and reliability of the filling equipment set, forming an integrated excavation and filling process and system with backward excavation between stages, skip mining within stages and timely filling. It is one of the more practical technical methods currently.

[0004] This invention is suitable for coal seam roofs and floors of moderate or higher stability, and for low- or high-gas mines. It addresses the technical challenges of excavating the return air chute at the upper working face, the transport chute at the lower working face, and the recovery and filling of the intermediate coal pillars, ultimately ensuring safe mining at adjacent working faces. It overcomes the complex group divisions, discontinuities between stages, and frequent adjustments to the roadway ventilation system inherent in the integrated progressive excavation and filling process and system.

[0005] The present invention adopts the following technical solutions:

[0006] A method for advanced replacement of coal pillars in a roadway by retreating continuous excavation and filling, comprising the following steps:

[0007] Step 1: Double tunnel excavation:

[0008] Tunnel excavation and coal pillar recovery can use one or more of the following equipment: roadheaders, anchor miners, continuous miners, and anchor miners. After the main equipment is determined, matching transportation and support equipment will be provided based on actual conditions. Here, a complete set of continuous miner equipment is used as an example, but it is not limited to a complete set of continuous mining equipment. First, complete the double tunnel excavation of the lower working face transport chute and the upper working face return air chute. The continuous coal miner cuts twice in the lower working face transport chute, cuts the coal into tunnels, and completes the coal loading through the machine body's built-in rake claws and transport part, and unloads the coal to the shuttle car. The shuttle car travels back and forth between the continuous coal miner and the crawler transfer crusher to complete the coal transfer. The crawler transfer machine completes the coal loading process, and the transport belt completes the coal transportation process. In the other return air chute, the support operation is completed by operating the anchor drill vehicle. The excavation heads of the two chute operate in parallel. After completion, they alternate through the joint tunnels. The continuous coal miner and shuttle car enter the return air chute to cut, load and transfer coal. The anchor drill vehicle enters the lower working face transport chute to complete the anchor protection operation. Joint tunnels are excavated at a certain interval, and the operation is cyclically alternating until all the excavation and anchor protection work of the two chute is completed.

[0009] Step 2: Group planning:

[0010] (1) Divide the coal pillars between the two chutes into several stages, named as I, II, III, etc.;

[0011] (2) Each stage is divided into A~J, with a total of 10 groups;

[0012] (3) Each group consists of 4 unit coal pillars and 1 tunneling joint;

[0013] The third step is coal pillar recovery and filling within the stage:

[0014] (1) After completing the transport chute and return air chute of the next working face, as well as the excavation and filling of the A-J group tunnels in each stage, the excavation equipment returns to the starting point of stage I;

[0015] (2) After the continuous miner retreats, it begins to turn and smooth the corners, excavating the unit coal pillar 2 of group A. The shuttle car travels back and forth between the continuous miner and the crawler-type transfer crusher. The traveling hydraulic support is placed in the trench near the turning and smoothing corners. The anchor drilling vehicle completes the roof and coal side support after excavation. After completing the excavation of the unit coal pillar 2 of group A, the excavation of the unit coal pillar 2 of group B is continued. The above process sequence is repeated until the recovery of the unit coal pillars 2 of groups A to J is completed.

[0016] (3) After completing the excavation of the unit coal pillar 2 of group A, the mining equipment continues to excavate the unit coal pillar 2 of group B. At the same time, the two sides of the unit coal pillar 2 of group A are sealed with filling templates 16 in the return air chute and the lower working face transport chute. The two filling templates 16 are tightened and reinforced with tension anchor cables 17. The space is sealed by spraying materials or sealing materials, and then the filling pipeline 18 is extended to complete the filling work. While the mining equipment continues to excavate the unit coal pillar 2 C3 of group C, the filling work of B3 is completed. The above process is repeated until the filling work of the unit coal pillar 2 of groups A to J is completed;

[0017] The fourth step is to complete the recovery and filling of coal pillars in the working lanes of phase I after the first round of joint lane recovery and filling and four rounds of unit coal pillar recovery and filling. Then, the coal pillar recovery and filling in the working lanes of phase I are completed, and the coal pillars are recovered and filled in the working lanes of phase I are completed. The coal pillars are recovered and filled in the working lanes of phase I are completed.

[0018] Furthermore, the length of the stages of the middle coal pillar division in the second step is 200-400 m.

[0019] Furthermore, the recovery of coal pillars within the stage adopts the skip mining process, and the skip mining order is A~J group No. 2 coal pillar → A~J group No. 4 coal pillar → A~J group No. 1 coal pillar → A~J group No. 3 coal pillar.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. Achieve efficient tunneling, recover coal pillars left between working faces, and simplify mining processes.

[0022] Rapid dual-lane excavation of the coal pillars was achieved, allowing for safe and efficient recovery of the central coal pillars before mining at the fully mechanized working faces on both sides, significantly improving resource recovery. Through rational planning and simplified mining techniques, forward tunneling, backward coal pillar recovery between stages, and grouped mining within stages, the mine was more efficient and time-efficient, streamlining on-site construction.

[0023] 2. Coordinate the relationship between procurement and supply to improve practicality and feasibility.

[0024] Coordinating the mining and filling relationship is mainly reflected in the overall arrangement of time and space. First, in terms of time, when the tunneling equipment is excavating the next group of unit coal pillars, the filling work is carried out in parallel to complete the filling of the previous group of recovered unit coal pillars. Through group skipping, sufficient solidification time is reserved for the unit coal pillar filling. Secondly, in terms of space, the coal transportation system is arranged in the lower working face transportation chute, and the filling pipeline is arranged in the return air chute for filling work. The space is reasonably allocated to solve the problems of tight mining and filling space and low efficiency of mining and filling interference. Through the above two aspects of planning, the practicality and feasibility of continuous mining and filling in coal pillar recovery have been greatly improved, and the coal resource recovery rate has been greatly improved.

[0025] 3. Reverse displacement separates tunneling and coal pillar recovery, reducing the workload for filling pipeline adjustments. This simplifies the tunneling process, allowing simultaneous tunneling of both tunnels and the connecting tunnel between them. This overcomes the complex internal group divisions and the frequent adjustments associated with the reciprocating advance between stages and within-stage skipping and skipping in the integrated tunneling and filling process and system. The early establishment of the tunnel system simplifies the tunnel ventilation system, achieving full-pressure ventilation after the completion of dual tunnel excavation. This early establishment of the tunnel system allows for the simultaneous laying of filling pipelines, reducing workload and streamlining the schedule for mining and filling. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is an integrated process and system for retreating coal pillar excavation and filling in the roadway;

[0027] Figure 2 Schematic diagram of working face stage and group planning;

[0028] Figure 3 This is a schematic diagram of the integrated excavation and filling working face;

[0029] Among them: 1- mining area transport tunnel; 2- mining area return air tunnel; 3- transport chute; 4- return air chute; 5- transport chute for the next working face; 6- mining working face; 7- goaf; 8- coal; 9- stage filling body; 10- continuous coal mining machine; 11- shuttle car; 12- walking hydraulic support; 13- crawler transfer crusher; 14- transport belt; 15- air duct; 16- filling formwork; 17- tension anchor cable; 18- filling pipeline; 19- heading tunnel; 20- third round filling body; 21- first round filling body; 22- fourth round filling body; 23- second round filling body.

[0030] A...H, I, J: group numbers within the stage; A1: Group A excavation joint tunnel; A2: Group A unit coal pillar 1; A3: Group A unit coal pillar 2; A4: Group A unit coal pillar 3; A5: Group A unit coal pillar 4. DETAILED DESCRIPTION

[0031] The present invention will be further described with reference to the accompanying drawings.

[0032] The present invention aims to provide a process and system for integrated retreat-type excavation and filling of inter-face coal pillars, suitable for coal seam roofs and floors with moderate or higher stability and low-gas or high-gas mine gas levels. This invention addresses the technical challenges of excavating the return air chute at the upper working face, the transport chute at the lower working face, and the recovery and filling of the intermediate coal pillars, ultimately ensuring safe mining of adjacent working faces. It also overcomes the problems inherent in the integrated forward excavation and filling process and system, such as complex group divisions, discontinuities between stages, and frequent adjustments to the roadway ventilation system.

[0033] 1. Double tunnel excavation and stage division

[0034] (1) Tunnel excavation and coal pillar recovery can be carried out by using one or more equipment such as tunnel boring machines, anchor miners, continuous miners, and integrated miners. After the main equipment is determined, the transportation and support equipment can be matched according to the actual situation. Here, the continuous miner equipment set is used as an example, but it is not limited to the continuous mining equipment set. The continuous mining equipment set completes the double tunnel excavation of the lower working face transport chute and the upper working face return air chute. The continuous miner 10 cuts twice in the transport chute 5 of the next working face, cuts the coal into tunnels, and completes the coal loading through the rake claws and transportation part of the machine body, and unloads the coal to the shuttle car 11. The shuttle car 11 travels back and forth between the continuous miner 10 and the crawler transfer crusher 13 to complete the coal transfer. The crawler transfer crusher 13 completes the coal loading process, and the transport belt 14 completes the coal transportation process. In the other return air chute 4, the support operation is completed by operating the anchor drilling vehicle. The tunneling heads of the two drifts operate in parallel, alternating through joint tunnels. The continuous miner 10 and shuttle car 11 enter the return air drift 4 to cut, load, and transport coal. The anchor drill enters the lower working face transport drift to complete the anchoring and support operations. Joint tunnels are excavated at regular intervals; here, a 30-meter joint tunnel is used for illustration. This cycle continues until all tunneling and anchoring work is complete in both drifts.

[0035] (2) In order to ensure the coordination of mining and filling and reduce the reciprocating movement, the middle coal pillars of the two chute are divided into several stages, named as I, II, III, etc., each stage is 200~400m, and 300m is used as an example here.

[0036] (3) During the excavation process, after the excavation of the next tunnel is completed, the two sides of the previous tunnel are sealed with filling templates 16. The two filling templates 16 are tightened and reinforced with tension anchors 17. The space is sealed by spraying materials or plugging materials. Then, the filling pipeline 18 is extended to complete the filling work. This cycle is repeated until all the planned tunnels between the two drifts are completed.

[0037] 2. Group planning

[0038] (1) Each stage is divided into A~J, with a total of 10 groups, each group is 30m long.

[0039] (2) Each group consists of 4 unit coal pillars and 1 tunneling tunnel. Taking group A as an example, it is divided into tunneling tunnel A1, unit coal pillar 1 A2, unit coal pillar 2 A3, unit coal pillar 3 A4, and unit coal pillar 4 A5.

[0040] (3) To facilitate the excavation of the continuous coal mining machine 10 and the installation of the filling template 16, the width of the unit coal pillar and the connecting roadway is 6~9m. Here, 6m is used as an example for explanation.

[0041] 3. Coal pillar recovery and filling in the completion stage

[0042] (1) After completing the excavation and filling of the transport drift 5 and the return air drift 4 of the next working face, as well as the A-J group tunnels in each stage, the excavation equipment retreats 300m to the starting point of stage I.

[0043] (2) After the continuous miner retreats, it begins to turn and smooth the corners, excavating the unit coal pillar 2 A3 of group A. The shuttle car 12 travels back and forth between the continuous miner 10 and the crawler-type transfer crusher 13. The traveling hydraulic support 12 is placed in the trench near the turning and smoothing point. The anchor drilling vehicle completes the roof and coal support after excavation. After completing the excavation of the unit coal pillar 2 A3 of group A, the excavation of the unit coal pillar 2 B3 of group B is continued. The above process sequence is repeated until the recovery of the unit coal pillars 2 of groups A to J is completed.

[0044] (3) After completing the excavation of the unit coal pillar 2 A3 of group A, the mining equipment continues to excavate the unit coal pillar 2 B3 of group B. At the same time, the two sides of the unit coal pillar 2 A3 of group A are sealed with filling templates 16 in the return air chute 4 and the next working face transport chute 5. The two filling templates 16 are tightened and reinforced with tension anchor cables 17. The space is sealed by spraying materials or sealing materials, and then the filling pipeline 18 is extended to complete the filling work. While the mining equipment continues to excavate the unit coal pillar 2 C3 of group C, the filling work of B3 is completed. The above process is repeated until the filling work of the unit coal pillar 2 of groups A to J is completed.

[0045] (4) In order to ensure the safety of mining operations and sufficient solidification time of the filling materials, the skip mining process is adopted. The skip mining sequence is A~J group No. 2 coal pillar → A~J group No. 4 coal pillar → A~J group No. 1 coal pillar → A~J group No. 3 coal pillar.

[0046] (5) In order to coordinate the mining and filling relationship, the excavation and filling process is adopted, that is, when the next group of unit coal pillars in the same stage are recovered, the unit coal pillars of the previous group that have just been recovered are filled. After the filling body reaches final setting, it is left to stand for a period of time, and then a second pressurized filling is carried out to complete the top connection and ensure subsequent mining work.

[0047] 4. Repeat the above steps to complete the recovery and filling of the coal pillars in the middle of the two chutes

[0048] After the first round of joint lane recovery and filling, and four rounds of unit coal pillar recovery and filling, the coal pillar recovery and filling between working faces in Phase I is completed. Continue to retreat to the starting position of Phase II and repeat the coal pillar recovery and filling in the same phase until the coal pillar recovery and filling between working faces is completed.

Claims

1. A method for advanced replacement of coal pillars in a roadway by retreating continuous excavation and filling, characterized by: The steps include: Step 1: Double tunnel excavation: The mining equipment can be selected from one or more of the following: tunnel boring machines, anchor boring machines, continuous coal miners, and integrated miner anchoring machines. After the main equipment is determined, the transportation and support equipment are matched according to the actual situation. The continuous mining equipment completes the double tunnel excavation of the lower working face transport chute and the upper working face return air chute. The continuous coal miner cuts twice in the lower working face transport chute, cuts the coal into tunnels, and completes the coal loading through the rake claws and transportation part of the machine body, and unloads the coal to the shuttle car. The shuttle car travels back and forth between the continuous coal miner and the crawler transfer crusher to complete the coal transfer. The crawler transfer machine completes the coal loading process, and the transport belt completes the coal transportation process. In the other return air chute, the support operation is completed by operating the anchor drilling vehicle. The tunneling heads of the two tunnels operate in parallel. After completion, they are alternated through the joint tunnel. The continuous coal miner and shuttle car enter the return air chute to cut, load and transfer coal. The anchor drilling vehicle enters the lower working face transport chute to complete the anchoring operation. The joint tunnel is excavated at a certain interval, and the operation is repeated until all the excavation and anchoring work of the two tunnels is completed. Step 2: Group planning: (1) Divide the coal pillars between the two chutes into several stages, named as I, II, III, etc.; (2) Each stage is divided into A~J, with a total of 10 groups; (3) Each group consists of 4 unit coal pillars and 1 tunneling joint; The third step is coal pillar recovery and filling within the stage: (1) After completing the transport chute and return air chute of the next working face, as well as the excavation and filling of the A-J group tunnels in each stage, the excavation equipment returns to the starting point of stage I; (2) After the continuous miner retreats, it begins to turn and smooth the corners, excavating the unit coal pillar 2 of group A. The shuttle car travels back and forth between the continuous miner and the crawler-type transfer crusher. The traveling hydraulic support is placed in the trench near the turning and smoothing corners. The anchor drilling vehicle completes the roof and coal side support after excavation. After completing the excavation of the unit coal pillar 2 of group A, the excavation of the unit coal pillar 2 of group B is continued. The above process sequence is repeated until the recovery of the unit coal pillars 2 of groups A to J is completed. (3) After the excavation of the unit coal pillar 2 of group A is completed, the mining equipment continues to excavate the unit coal pillar 2 of group B. At the same time, the two sides of the unit coal pillar 2 of group A are sealed with filling templates (16) in the return air chute and the lower working face transport chute. The two filling templates (16) are tightened and reinforced with tension anchor cables (17). The space is sealed by spraying materials or sealing materials, and then the filling pipeline (18) is extended to complete the filling work; while the mining equipment continues to excavate the unit coal pillar 2 C3 of group C, the filling work of B3 is completed. The above process is repeated until the filling work of the unit coal pillar 2 of groups A to J is completed; The fourth step is to complete the recovery and filling of coal pillars in the working lanes of phase I after the first round of joint lane recovery and filling and four rounds of unit coal pillar recovery and filling. Then, the coal pillar recovery and filling in the working lanes of phase I are completed, and the coal pillars are recovered and filled in the working lanes of phase I are completed. The coal pillars are recovered and filled in the working lanes of phase I are completed.

2. The method for advanced replacement of coal pillars in a roadway by retreating continuous excavation and filling according to claim 1 is characterized in that: The length of the stage of the middle coal pillar division in the second step is 200~400m.

3. The method for advanced replacement of coal pillars in a roadway by retreating continuous excavation and filling according to claim 1 is characterized in that: The coal pillars within the stage are recovered by skip mining technology, and the skip mining order is A~J group No. 2 coal pillar → A~J group No. 4 coal pillar → A~J group No. 1 coal pillar → A~J group No. 3 coal pillar.

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