Top coal caving mining method and system for medium-thick coal seams with extremely large inclination angles

Abstract

The present invention provides a method and system for top coal caving mining in a medium-thick coal seam with a particularly steep inclination. A vertical and horizontal U-shaped ventilation system is formed by connecting a process connection tunnel with an upper return air tunnel and a lower air intake and transportation tunnel to ensure timely ventilation during coal mining. Through the development and layout of the tunnel and the installation of mining equipment, the medium-thick coal seam with a particularly steep inclination is changed from a large-angle pseudo-inclined long-arm mining method to a vertical caving top coal caving mining method, which can effectively recover the coal between the upper return air tunnel and the lower air intake and transportation tunnel, realize the mechanized mining of the medium-thick coal seam with a particularly steep inclination, effectively solve the safety problem of mechanized mining at a particularly steep inclination, and has a high mining efficiency. The mining equipment is stable and easy to install.

Description

Technical Field

[0001] The invention belongs to the technical field of mining engineering, and in particular relates to a top coal caving mining method and system for a medium-thick coal seam with an extremely large inclination angle. Background Art

[0002] The occurrence conditions of steeply inclined coal seams have always been the focus of the current industry. Due to the difficulty of mechanized mining of steeply inclined coal seams, mining of steeply inclined coal seams usually adopts blasting mining or abandoned mining, resulting in a large amount of resource waste, low production efficiency, and frequent safety accidents. Therefore, how to safely and effectively mine coal resources under the conditions of steeply inclined coal seams is one of the problems that the coal industry needs to solve.

[0003] The evolution of domestic mining methods in steeply inclined coal seams can be summarized into the following five stages:

[0004] The first development stage: In the early 1950s, domestic front-line technical researchers adopted different methods according to different geological conditions, including reverse benching, horizontal stratification, long wall and pitch, pneumatic pick coal dropping, etc. Compared with the previous method, it not only improved the production capacity of coal mining enterprises, reduced the labor intensity of workers and improved the working environment, but also changed the technical and economic prospects of steeply inclined coal seams for the first time.

[0005] The second development stage: Starting from the 1960s, the steeply inclined coal seams were mainly blasted by electric drills, replacing the first pneumatic pick method. In order to expand the application scope of the shielding support, the shielding support of "eight" and "7" shapes was used in Huainan and other mining areas. Compared with the flat shielding support, it achieved good economic benefits. At the same time, metal pillars and metal articulated top beams were gradually adopted to improve the mining technology of the steeply inclined working face, which also achieved good technical and economic results.

[0006] The third development stage: In the mid-1970s, the main method was the pseudo-inclined flexible shield support mining method, with the Huainan mining area as a typical case. This method has the advantages of good output, simple process, small excavation volume, safety and high efficiency, and is still used in mining areas. In order to improve the degree of mechanization under this condition, Jixi, Panzhihua, Huainan and other mining areas have conducted experiments on drum coal mining machines, impact plows and ditches. In addition, similar experiments have been carried out in other mining areas, but the success rate is not high and cannot be promoted on a large scale.

[0007] The fourth development stage: In the late 1980s and early 1990s, the mining methods of steeply inclined coal seams were further improved. The length of the working face, the increase in unit yield and the safety production conditions were further improved. For example, the successful dive, inclined, long-wall horizontal segmented coal mining method in the test of Xuntian Coal Mine of Sichuan Furong Mining Bureau is a short-wall coal mining method with the characteristics of large production, good ventilation conditions and convenient roof management.

[0008] The fifth development stage: From the mid-1990s to the present, it has entered the stage of popularization and promotion of comprehensive mechanized mining of steeply inclined medium-thick, thick and extra-thick coal seams.

[0009] In the past thirty years, seven methods of mining steeply inclined coal seams have been basically formed in terms of mining steeply inclined medium-thick coal seams, thick coal seams and extra-thick coal seams, including: horizontal layer comprehensive mining with top coal caving; tunnel pillar-horizontal layer comprehensive mining with top coal caving; inclined layer changing inclination direction long wall comprehensive mining with top coal caving; inclined direction long wall variable line layout comprehensive mining with top coal caving; inclined layer direction long wall comprehensive mining with top coal caving; inclined direction long wall pseudo-inclined layout comprehensive mining with full height at one time; tunnel pillar comprehensive mining with top coal caving. These methods still do not effectively solve the problem of mechanized mining of coal seams with a thickness of 1 to 5 meters and a coal seam inclination angle of 45 to 90 degrees, and are still using traditional flexible shield support blasting technology, such as Figure 1 and 2 As shown, there are huge technical safety issues, and the state has proposed closing such mines many times.

[0010] like Figure 1 and Figure 2 As shown, the pseudo-inclined long-arm working face of the traditional flexible shielding support is arranged as a coal seam 104, a rock layer 102, a broken rock layer 101, an upper return air tunnel 105, a support 103, and a lower air intake and transportation tunnel 106. The inclination of the coal seam is in the range of 45 to 90 degrees. Due to the large inclination, the anti-falling and anti-slip settings of the comprehensive mining equipment cannot be set, the construction management of the personnel is difficult, the safety hazards are great, and it is difficult to achieve mechanized mining. Summary of the invention

[0011] In order to solve the above technical problems, the present invention provides a method and system for top coal caving mining in medium-thick coal seams with an extremely large inclination angle. The present invention adopts the following technical solutions:

[0012] In some optional embodiments, a method for top coal caving mining in a medium-thick coal seam with an extremely steep inclination is provided, comprising: drilling a lower air intake and transportation tunnel in the coal seam, and the end of the lower air intake and transportation tunnel serves as a coal dropping working face, and drilling an upper return air tunnel above the coal dropping working face; drilling a process connection tunnel on the rock layer on the side of the coal seam, and the process connection tunnel is respectively connected with the upper return air tunnel and the lower air intake and transportation tunnel; installing mining equipment in the lower air intake and transportation tunnel; a local main fan installed in the upper return air tunnel is operated so that wind enters along the lower air intake and transportation tunnel, flows into the upper return air tunnel through the process connection tunnel and is discharged; the falling rock mass pushes the loosened coal at its bottom to flow downward, and the coal discharge plug plate on the hydraulic support after the coal return in the mining equipment performs a telescopic action, so that the flowing coal falls onto the transfer machine in the mining equipment, and when the coal stops flowing, the coal discharge tail beam on the hydraulic support after the coal return swings to loosen the coal and make it flow.

[0013] In some optional embodiments, the method for mining top coal in a medium-thick coal seam with an extremely steep inclination angle further includes: opening a plurality of safety control holes leading to the coal seam or the rock stratum in the process connection tunnel.

[0014] In some optional embodiments, the process of installing the mining equipment in the lower air intake and transport tunnel includes: overlapping the head of the transfer machine on the transfer pulley of the mining equipment, installing the transfer pulley on the track in the mining equipment, and laying the belt conveyor in the mining equipment parallel to the track in the lower air intake and transport tunnel.

[0015] In some optional embodiments, the present invention further provides a top coal caving mining system for medium and thick coal seams with extremely steep inclinations, comprising: mining equipment arranged in a lower air intake and transportation tunnel; the mining equipment comprises: a hydraulic support before coal return, a hydraulic support after coal return and a transfer machine, the ends of the transfer machine are arranged in the hydraulic support before coal return and the hydraulic support after coal return, a swing cylinder and a coal-releasing tail beam are arranged on the hydraulic support after coal return, the action end of the swing cylinder is connected to the coal-releasing tail beam, so that when the swing cylinder performs a telescopic movement, it drives the coal-releasing tail beam to swing on the hydraulic support after coal return; a telescopic cylinder and a coal-releasing plug plate are arranged on the coal-releasing tail beam, the action end of the telescopic cylinder is connected to the coal-releasing plug plate, so that when the telescopic cylinder is actuated, it drives the coal-releasing plug plate to move back and forth on the coal-releasing tail beam; and also comprises: a local main fan arranged in the upper return air tunnel.

[0016] In some optional embodiments, the mining equipment also includes: a transfer pulley, a track and a belt conveyor; one end of the transfer machine is arranged in the front hydraulic support and the rear hydraulic support of the coal return, and the other end is hinged to the transfer pulley, the transfer pulley is arranged on the track, and the belt conveyor is parallel to the track and laid in the lower air intake and transport tunnel.

[0017] The beneficial effects brought about by the present invention are as follows: a vertical and horizontal U-shaped ventilation system is formed by connecting the process connecting tunnel with the upper return air tunnel and the lower air intake and transportation tunnel to ensure timely ventilation during coal mining. Through the development and layout of the tunnels and the installation of mining equipment, the large-angle pseudo-inclined long-arm mining method of the medium and thick coal seams is changed to a vertical caving and top coal mining method, which can effectively recover the coal between the upper return air tunnel and the lower air intake and transportation tunnel, realize the mechanized mining of the medium and thick coal seams with extremely large inclinations, effectively solve the safety problems of mechanized mining with extremely large inclinations, and have higher mining efficiency. The mining equipment is stable and easy to install. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1This is a schematic diagram of the pseudo-oblique long arm working surface layout of the traditional flexible shielding support;

[0019] Figure 2 This is a schematic diagram of the support section of the coal mining face using a traditional flexible shield support;

[0020] Figure 3 It is a schematic diagram of the space arrangement of the laneway of the present invention;

[0021] Figure 4 It is a schematic diagram of the tunnel plane layout of the present invention;

[0022] Figure 5 It is a schematic diagram of the arrangement of the hydraulic support before coal return and the hydraulic support after coal return of the present invention;

[0023] Figure 6 This is a schematic diagram of the installation layout of the mining equipment of the present invention;

[0024] Figure 7 This is a schematic diagram of the installation layout of the transfer machine of the present invention;

[0025] Figure 8 It is a schematic diagram of the upper return air lane, the process connection lane and the lower air intake and transportation lane of the present invention;

[0026] Fig. 9 It is a cross-sectional schematic diagram of the tunnel space layout of the present invention. DETAILED DESCRIPTION

[0027] The following description and accompanying drawings fully demonstrate specific embodiments of the present invention so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent possible variations only. Unless clearly required, separate components and functions are optional, and the order of operation may vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments.

[0028] like Figures 3 to 9 As shown, in some illustrative embodiments, the present invention provides a method for top coal caving mining in a medium-thick coal seam with an extremely steep inclination, including: tunnel construction, equipment installation and production process.

[0029] The tunnel construction includes: selecting a coal seam 1 of the required height, drilling a lower air intake and transportation tunnel 5 in the coal seam 1, and the end of the lower air intake and transportation tunnel 5 is used as a coal-dropping working face 6, that is, the lower air intake and transportation tunnel 5 is at the same level as the coal-dropping working face 6, and drilling an upper return air tunnel 3 on the upper part of the coal-dropping working face 6. At the same time, construct a process connection tunnel 4, drill a process connection tunnel 4 on the rock layer 2 on the side of the coal seam 1, and the process connection tunnel 4 is connected to the upper return air tunnel 3 and the lower air intake and transportation tunnel 5 respectively.

[0030] The tunnel construction process also includes: opening a number of safety control holes 15 leading to the coal seam 1 or the rock layer 2 in the process connection tunnel 4. The function of the safety control holes 15 is to deal with the looseness of the coal seam 1 and gas extraction, and at the same time deal with the caving of the overlying rock layer 2 on the coal seam 1 and various water on the upper part, eliminating the safety hazards of coal mining.

[0031] The equipment installation includes: installing mining equipment in the lower air intake and transportation tunnel 5. The process of installing mining equipment in the lower air intake and transportation tunnel includes: installing tracks 7 in the lower air intake and transportation tunnel 5 for transporting the installed equipment, first installing the hydraulic support 11 before coal return and the hydraulic support 12 after coal return, and then installing the transfer machine 10 and the transfer pulley 8, the transfer machine 10 is hinged to the hydraulic support 11 before coal return, the head of the transfer machine 10 is overlapped on the transfer pulley 8 of the mining equipment, the transfer pulley 8 is installed on the track 7, and the belt conveyor 9 parallel to the track 7 is laid in the lower air intake and transportation tunnel 5.

[0032] The local main fan 17 is installed in the upper return air tunnel 3, and its position is at the intersection of the upper return air tunnel 3 and the process connection tunnel 4. The function of the local main fan 17 is to extract the harmful gas generated by the scattered coal 19 on the upper part of the coal falling working face 6 into the upper return air tunnel 3, and at the same time accelerate the wind speed flow in the upper return air tunnel 3.

[0033] The production process includes:

[0034] The local main fan 17 works, so that the wind 16 enters along the lower air inlet and transport tunnel 5, flows into the upper return air tunnel 3 through the process connection tunnel 4 and is discharged. The local main fan 17 discharges the gas above the coal falling working face 6 and accelerates the gas flow in the upper return air tunnel 3;

[0035] The falling rock mass 18 pushes the loosened coal at its lower part to flow downward, and the coal discharge plug plate 14 on the hydraulic support 12 after the coal return performs a telescopic movement, so that the flowing coal falls onto the transfer machine 10 in the mining equipment, and the scattered coal 19 falls onto the tail of the transfer machine 10, and the scattered coal 19 is transported to the ground through the transfer machine 10 through the belt conveyor 9, and when the coal stops flowing, the coal discharge tail beam 20 on the hydraulic support 12 after the coal return swings to loosen the coal and make it flow.

[0036] In some illustrative embodiments, the present invention further provides a top coal caving mining system for a medium-thick coal seam with an extremely steep inclination, comprising: mining equipment arranged in a lower air intake and transportation tunnel 5 .

[0037] The mining equipment includes: a hydraulic support 11 before coal return, a hydraulic support 12 after coal return, a transfer machine 10, a transfer pulley 8, a track 7, a belt conveyor 9, a swing cylinder 13, a coal discharge tail beam 20, a telescopic cylinder 21 and a coal discharge plug plate 14.

[0038] One end of the transfer machine 10 is arranged in the hydraulic support 11 before coal return and the hydraulic support 12 after coal return, and the other end is hinged to the transfer pulley 8. The transfer pulley 8 is arranged on the track 7, and the belt conveyor 9 is parallel to the track 7 and laid in the lower air intake transport tunnel 5.

[0039] A swinging cylinder 13 and a coal-releasing tail beam 20 for loosening the coal seam are arranged on the hydraulic support 12 after coal return, and the coal-releasing tail beam 20 is hinged to the hydraulic support 12 after coal return; the action end of the swinging cylinder 13 is connected to the coal-releasing tail beam 20, and the fixed end is connected to the hydraulic support 12 after coal return. When the swinging cylinder 13 performs telescopic movement, it drives the coal-releasing tail beam 20 to swing on the hydraulic support 12 after coal return, thereby loosening the scattered coal 19.

[0040] A telescopic cylinder 21 and a coal placing plug plate 14 for blocking and placing coal are arranged in the coal placing tail beam 20. The action end of the telescopic cylinder 21 is connected to the coal placing plug plate 14. When the telescopic cylinder 21 is actuated, the coal placing plug plate 14 is driven to move back and forth on the coal placing tail beam 20, that is, the coal placing plug plate 14 is telescoped on the coal placing tail beam 20. When the falling rock mass 18 pushes the scattered coal 19 to fall, the coal placing plug plate 14 is telescoped to realize coal placing.

[0041] The action end of the oil cylinder refers to the end that moves when the oil cylinder is working, and the other end is the fixed end. The hydraulic support 12 after coal return, the hydraulic support 11 before coal return and the transfer machine 10 guide each other to move.

[0042] The top coal caving mining system for medium-thick coal seams with a large inclination angle of the present invention also includes: a local main fan 17 arranged in the upper return air tunnel 3, which is located at the intersection of the upper return air tunnel 3 and the process connection tunnel 4. The function of the local main fan 17 is to extract the harmful gas generated by the scattered coal 19 on the upper part of the coal-dropping working face 6 into the upper return air tunnel 3, and at the same time accelerate the wind speed flow in the upper return air tunnel 3.

[0043] The top coal caving mining system for medium-thick coal seams with extra-high inclination angles of the present invention requires tunnel construction before use, and the tunnel construction includes: drilling a lower air intake and transportation tunnel 5 in the coal seam 1, and the end of the lower air intake and transportation tunnel 5 serves as a coal-dropping working face 6, that is, the lower air intake and transportation tunnel 5 is at the same level as the coal-dropping working face 6, and an upper return air tunnel 3 is drilled on the upper part of the coal-dropping working face 6. A process connection tunnel 4 is drilled on the rock layer 2 on the side of the coal seam 1, and the process connection tunnel 4 is connected to the upper return air tunnel 3 and the lower air intake and transportation tunnel 5, respectively. A number of safety control holes 15 leading to the coal seam 1 or the rock layer 2 are opened in the process connection tunnel 4. The function of the safety control hole 15 is to deal with the looseness and gas extraction of the coal seam 1, and at the same time deal with the caving of the overlying rock layer 2 on the coal seam 1 and various water on the upper part, so as to eliminate the safety hazards of coal mining.

[0044] The process of installing the mining equipment in the lower air intake and transportation tunnel 5 includes: installing a track 7 in the lower air intake and transportation tunnel 5 for transporting the installed equipment, first installing the hydraulic support 11 before the coal return and the hydraulic support 12 after the coal return, and then installing the transfer machine 10 and the transfer pulley 8. The transfer machine 10 is hinged to the hydraulic support 11 before the coal return, and the head of the transfer machine 10 is overlapped on the transfer pulley 8 of the mining equipment, and the transfer pulley 8 is installed on the track 7, and the belt conveyor 9 parallel to the track 7 is laid in the lower air intake and transportation tunnel 5.

[0045] The local main fan 17 works, so that the wind 16 enters along the lower air inlet and transport tunnel 5, flows into the upper return air tunnel 3 through the process connecting tunnel 4 and is discharged. The local main fan 17 discharges the gas above the coal falling working face 6 and accelerates the gas flow in the upper return air tunnel 3.

[0046] The falling rock mass 18 pushes the loosened coal at its lower part to flow downward, and the coal discharge plug plate 14 on the hydraulic support 12 after the coal return performs a telescopic movement, so that the flowing coal falls onto the transfer machine 10 in the mining equipment, and the scattered coal 19 falls onto the tail of the transfer machine 10, and the scattered coal 19 is transported to the ground through the transfer machine 10 through the belt conveyor 9, and when the coal stops flowing, the coal discharge tail beam 20 on the hydraulic support 12 after the coal return swings to loosen the coal and make it flow.

[0047] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

Claims

1. A method for mining top coal in a medium-thick coal seam with a particularly steep inclination, characterized in that: Applied to medium and thick coal seams with large dip angles, including: A lower air intake and transport tunnel is drilled in the coal seam, and the end of the lower air intake and transport tunnel serves as a coal dropping working face, and the lower air intake and transport tunnel is at the same level as the coal dropping working face; an upper return air tunnel is drilled above the coal dropping working face; A process connection tunnel is drilled on the rock layer on the side of the coal seam, and the process connection tunnel is connected with the upper return air tunnel and the lower air intake and transportation tunnel respectively; Installing mining equipment in the lower air intake and transport tunnel; The local main fan installed in the upper return air lane works so that the wind enters along the lower air inlet and transport lane, flows into the upper return air lane through the process connection lane and is discharged; The falling rock mass pushes the loosened coal at its bottom to flow downward, and the coal-releasing plug plate on the hydraulic support after coal return in the mining equipment retracts and contracts, so that the flowing coal falls onto the transfer machine in the mining equipment, and when the coal stops flowing, the coal-releasing tail beam on the hydraulic support after coal return swings to loosen the coal and make it flow.

2. The top coal caving mining method for medium-thick coal seams with a large inclination angle according to claim 1 is characterized in that: Also includes: A plurality of safety control holes leading to the coal seam or the rock layer are opened in the process connection tunnel.

3. The top coal caving mining method for medium-thick coal seams with a large inclination angle according to claim 2 is characterized in that: The process of installing the mining equipment in the lower air intake and transportation tunnel includes: overlapping the head of the transfer machine on the transfer pulley of the mining equipment, installing the transfer pulley on the track in the mining equipment, and laying the belt conveyor in the mining equipment parallel to the track in the lower air intake and transportation tunnel.

4. Extra-large-angle medium-thick coal seam top coal caving mining system, characterized by: The method for top coal caving mining in a medium-thick coal seam with an extremely steep inclination as described in any one of claims 1-3; comprising: mining equipment arranged in a lower air intake and transportation tunnel; the mining equipment comprises: a hydraulic support before coal return, a hydraulic support after coal return and a transfer machine, the ends of the transfer machine are arranged in the hydraulic support before coal return and the hydraulic support after coal return, a swing cylinder and a coal-releasing tail beam are arranged on the hydraulic support after coal return, the action end of the swing cylinder is connected to the coal-releasing tail beam, so that when the swing cylinder performs a telescopic movement, the coal-releasing tail beam is driven to swing on the hydraulic support after coal return; a telescopic cylinder and a coal-releasing plug plate are arranged on the coal-releasing tail beam, the action end of the telescopic cylinder is connected to the coal-releasing plug plate, so that when the telescopic cylinder is actuated, the coal-releasing plug plate is driven to move back and forth on the coal-releasing tail beam; also comprising: a local main fan arranged in the upper return air tunnel.

5. The top coal caving mining system for medium-thick coal seams with a large inclination angle according to claim 4 is characterized in that: The mining equipment also includes: a transfer pulley, a track and a belt conveyor; one end of the transfer machine is arranged in the front hydraulic support and the rear hydraulic support of the coal return, and the other end is hinged to the transfer pulley, the transfer pulley is arranged on the track, and the belt conveyor is parallel to the track and laid in the lower air intake and transportation tunnel.

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