CN111219191B

CN111219191B - Ultra-thin coal seam longwall mining method based on N00 construction method

Info

Publication number: CN111219191B
Application number: CN202010330365.6A
Authority: CN
Inventors: 何满潮; 王�琦; 王亚军; 刘简宁
Original assignee: Beijing Zhongkuang Innovation Alliance Energy Environment Science Academy
Current assignee: Beijing Zhongkuang Innovation Alliance Energy Environment Science Academy
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2020-07-31
Anticipated expiration: 2040-04-24
Also published as: CN111219191A

Abstract

The disclosure provides a long-wall mining method of an ultra-thin coal seam based on an N00 construction method, and relates to the technical field of mining. The mining method comprises the following steps: carrying out advance operation on the working surface along the direction vertical to the working surface to form a first roadway, and supporting the first roadway to form a first crossheading; forming an advance working area in the first gate way; simultaneously mining coal from the coal mining machine to two sides of the first gateway along the direction parallel to the working face in the advance working area, and conveying the coal mining body to a scraper conveyor; blasting the working face to form a second roadway when the coal mining machine located on one side of the first crossheading runs to a first preset position, and supporting the second roadway to form a second crossheading; and blasting the working face to form a third roadway when the coal mining machine on the other side of the first crossheading runs to a second preset position, and supporting the third roadway to form a third crossheading. The mining method disclosed by the invention can avoid tunneling a roadway in advance, reduce the coal mining cost, improve the coal mining efficiency and avoid resource waste.

Description

Ultra-thin coal seam longwall mining method based on N00 construction method

Technical Field

The disclosure relates to the technical field of mining, in particular to a long-wall mining method of an ultra-thin coal seam based on an N00 construction method.

Background

Coal is widely used in life and industrial production as one of the main energy sources. With the development of science and technology, people have increasingly growing demands for coal resources, and efficient coal resource exploitation is particularly important.

The ultra-thin coal seam is a common coal seam distribution form, the ultra-thin coal seam is usually mined by adopting a high-grade common mining face-to-face mining process, a plurality of tunnels need to be excavated in advance before mining, and the tunnels are supported in a mode of reserving coal pillars in each tunnel. In order to ensure that the coal seam in the extremely-thin coal seam is completely exposed, the tunnels dug by the extremely-thin coal seam are all half-coal-rock tunnels, so that the tunnel digging difficulty is higher, the digging time is longer, the coal mining efficiency is lower, and the cost is higher; meanwhile, the coal pillars are left in the roadway and cannot be recovered, so that coal resource waste is caused.

Disclosure of Invention

The purpose of the disclosure is to overcome the defects in the prior art, and provide a long-wall mining method of an ultra-thin coal seam based on an N00 construction method, which can avoid tunneling a roadway in advance, reduce coal mining cost, improve coal mining efficiency and avoid resource waste.

According to one aspect of the disclosure, there is provided a method for longwall mining of an ultra-thin coal seam based on an N00 method, comprising:

carrying out advanced operation on the working surface along the direction vertical to the working surface to form a first roadway, and supporting the first roadway to form a first crossheading;

performing advanced operation on the coal wall of the working surface in the first gate way to form an advanced working area;

simultaneously mining coal from both sides of the first gate way along a direction parallel to the working face in the advance working area by adopting a coal mining machine, and conveying the coal bodies to a scraper conveyor;

when the coal mining machine located on one side of the first crossheading runs to a first preset position, performing advanced blasting on the working face to form a second roadway, and supporting the second roadway to form a second crossheading; and when the coal mining machine on the other side of the first crossheading runs to a second preset position, performing advanced blasting on the working face to form a third roadway, and supporting the third roadway to form a third crossheading.

In an exemplary embodiment of the present disclosure, the supporting the first roadway to form a first gate way includes:

adopting a temporary support system to temporarily support the first roadway, wherein the temporary support system comprises a single strut;

and permanently supporting the side wall and the top plate of the first roadway by adopting a permanent supporting system to form a first crossheading, wherein the permanent supporting system comprises an anchor cable support and a U-shaped steel support.

In an exemplary embodiment of the present disclosure, the mining method further comprises:

a four-beam eight-column and tail beam supporting system is adopted to support the joint of the first roadway and the working face;

arranging a reversed loader in the advanced working area and communicating the reversed loader with the end part of the scraper conveyor, wherein the reversed loader is used for receiving the coal conveyed by the scraper conveyor;

and one end of a belt conveyor is connected with the reversed loader, and the other end of the belt conveyor extends to the outside of the first gate way and is used for conveying the coal body to the outside of the first gate way.

and adopting a single support system to support one side of the coal mining machine, which is far away from the coal wall of the working face, in real time in the coal mining process of the coal mining machine.

In an exemplary embodiment of the present disclosure, a goaf is between the first and second gate roads, the mining method further comprising:

sealing the side wall of the first gate way close to the goaf by adopting concrete;

and sealing the side wall of the second gate way close to the goaf by adopting concrete.

In an exemplary embodiment of the present disclosure, a goaf is between the first and third gate roads, the mining method further comprising:

and sealing the side wall of the third gate way close to the goaf by adopting concrete.

temporarily supporting the side wall and the top of the second roadway by adopting the temporary supporting system and the permanent supporting system to form a second gate way;

and carrying out temporary support on the side wall and the top of the third roadway by adopting the temporary support system and the permanent support system to form the third gate way.

In an exemplary embodiment of the disclosure, the advancing the coal wall of the working face in the first gate way, and forming an advance working area includes:

and blasting the coal wall of the working face in the first gate way by adopting a blasting technology to generate a leading working area with a preset length.

In an exemplary embodiment of the present disclosure, the preset length ranges from 1.6m to 2.0 m.

In an exemplary embodiment of the disclosure, a distance between the first preset position and the first gate way is equal to a distance between the second preset position and the first gate way.

According to the ultra-thin coal seam longwall mining method based on the N00 construction method, the first crossheading, the second crossheading and the third crossheading can be formed in the process of tunneling a working face and a coal seam, the phenomenon that a roadway is tunneled in advance is avoided, a coal pillar does not need to be reserved, the labor, material and time costs are saved, accordingly, the resource waste is avoided, the coal mining cost is reduced, and the coal mining efficiency is improved. In the process, only advance operation is needed to be carried out on the first crossheading to ensure that the coal mining machine can enter the first crossheading, the tunneling work amount is small, and the time required by tunneling is short; still can carry out the operation in advance in first crossheading and form the advance workspace, can pack the waste rock that working face and first crossheading lateral wall dropped in the collecting space area around the first crossheading at the operation in-process, realize that zero waste rock of working face discharges, eliminates the cost of transportation of waste rock, still can utilize the self-supporting power of waste rock, reduces tunnel roof pressure intensity, reduces the support cost in tunnel. The coal body mined by the coal mining machine can be conveyed to the scraper conveyor, so that the coal body can be conveyed out through the scraper conveyor. In addition, because the first crossheading, the second crossheading and the third crossheading are communicated with each other, ventilation can be performed through the second crossheading and the third crossheading, and the problem of ventilation of a mining area is solved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

FIG. 1 is a schematic diagram of mining a very thin coal seam in the related art.

Fig. 2 is a schematic view of a mining area in the related art.

Fig. 3 is a flow chart of a longwall mining method of an ultra-thin coal seam based on an N00 construction method according to an embodiment of the present disclosure.

FIG. 4 is a schematic diagram of longwall mining of an ultra-thin coal seam based on an N00 construction method according to an embodiment of the disclosure.

Fig. 5 is a schematic sectional view taken along the direction a-a in fig. 4.

Fig. 6 is a schematic cross-sectional view taken along the direction B-B in fig. 4.

Fig. 7 is a schematic cross-sectional view taken along the direction C-C in fig. 4.

Fig. 8 is a schematic cross-sectional view taken along the direction D-D in fig. 4.

In the figure: 100. a working face material roadway; 200. a scraper machine; 300. a hydraulic support; 400. a coal mining machine; 500. the working faces share a haulage roadway; 600. a mining area; 601. an air return downstroke passage; 602. a track descending passage; 603. a belt descending passage; 1. a first gate way; 11. a lead working area; 12. a temporary support system; 13. a four-beam eight-column and tail beam support system; 14. a single support system; 15. a first preset position; 16. a coal seam; 17. a coal seam roof; 2. a scraper conveyor; 21. a reversed loader; 22. a belt conveyor; 23. gangue; 24. an anchor rod; 3. a coal mining machine; 4. a second gate way; 5. a third gate way; 6. a gob; 7. and (3) concrete.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," and "said" are used to indicate the presence of one or more elements/components/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc. The terms "first," "second," and "third" are used merely as labels, and are not limiting as to the number of their objects.

In the related art, as shown in fig. 1, when mining an extremely thin coal seam, two face material tunnels 100 and a face common haulage tunnel 500 need to be excavated in advance, and adjacent tunnels in the three tunnels are all faces, and the face common haulage tunnel 500 located at the middle part is used as a common tunnel. In the mining process, a coal mining machine 400, a scraper 200 and a hydraulic support 300 are arranged in each working face material roadway 100, so that two working faces can simultaneously mine coal. However, in order to ensure that the working faces are coal walls, the two working face material tunnels 100 which are excavated in advance need to be half coal rock tunnels, the excavation efficiency of the tunnels is extremely low, and coal pillars need to be reserved to support the tunnels in the excavation process, so that a large amount of coal resources are wasted.

As shown in fig. 2, in another mining method, at least one mining area 600 is included in a mining area, before the mining of the working face, the mining area 600 needs to advance to dig an air return downhill passage 601, a track downhill passage 602 and a belt downhill passage 603 for satisfying the functions of ventilation, pedestrians, transportation and the like of the working face, so that the advance tunneling amount of the roadway is large, the preparation time in the early stage of coal production is too long, the cost of coal production is increased, a large amount of manpower, material resources and time are wasted, and safety accidents are easily caused in the tunneling process of the roadway.

The disclosed embodiment provides an ultra-thin coal seam longwall mining method based on an N00 construction method, as shown in FIG. 3, the mining method may include:

step S110, performing advance operation on the working surface along a direction perpendicular to the working surface to form a first roadway, and supporting the first roadway to form a first crossheading;

step S120, performing advanced operation on the coal wall of the working surface in the first gate way to form an advanced working area;

step S130, a coal mining machine is adopted to simultaneously mine coal to two sides of the first gateway along the direction parallel to the working face in the advance working area, and the coal mining body is conveyed to a scraper conveyor;

step S140, when the coal mining machine positioned on one side of the first crossheading runs to a first preset position, performing advanced blasting on the working face to form a second roadway, and supporting the second roadway to form a second crossheading; and when the coal mining machine on the other side of the first crossheading runs to a second preset position, performing advanced blasting on the working face to form a third roadway, and supporting the third roadway to form a third crossheading.

The steps of the ultra-thin coal seam longwall mining method based on the N00 construction method according to the embodiment of the present disclosure will be described in detail below:

as shown in fig. 3, in step S110, a first roadway is formed by advancing the working surface in a direction perpendicular to the working surface, and the first roadway is supported to form a first gate way.

The face may be where the tunnelling work is initiated when the coal or rock is mined and may move as the progress of the tunnelling changes. The working surface may be a plane or a curved surface, and is not particularly limited herein. As shown in fig. 4, the working surface can be advanced in a direction perpendicular to the working surface to form a first roadway, and the side wall and the top of the first roadway can be supported to form a first gate way 1. The first gate way 1 can be used for transporting coal bodies, and the width of the first gate way can be 3 m-4 m. For example, it may be 3m, 3.2m, 3.4, 3.6, 3.8 or 4m, and of course, other widths may be set according to the actual engineering requirement, which is not limited herein.

For example, as shown in fig. 8, a temporary support system 12 may be used to temporarily support a first roadway to prevent the mine spoil 23 from falling and causing injury to workers. In one embodiment, the temporary support system 12 may include a single prop, one end of which may be supported below the floor of the first roadway and the other end of which may be supported on the roof of the first roadway to prevent the first roadway roof rock mass from falling. The single prop can have a plurality ofly, and a plurality of single props can be according to presetting interval evenly distributed in first tunnel. For example, the single prop may be a hydraulic prop, but of course, other props may be used for supporting, and is not limited herein.

Simultaneously, can adopt the permanent supporting system to carry out the permanent support in order to form first crossheading 1 to the lateral wall and the roof of first tunnel, the permanent supporting system can include that anchor bolt support and U shaped steel are strutted, particularly, can set up the roof at first tunnel top for prevent that first tunnel top waste rock 23 from dropping, can set up a plurality of stock 24 according to preset's interval equidistant side by side in the both sides of tunnel roof simultaneously, and accessible stock 24 top is supported in first tunnel roof fixedly. Of course, the top plate can also be fixed to the top of the first roadway by using the bracket, and the fixing mode of the top plate of the first roadway is not particularly limited. Simultaneously, can push up U shaped steel shop between first tunnel roof and first tunnel bottom plate to can laminate U shaped steel in the lateral wall in first tunnel, and then prevent that coal seam roof 17 in waste rock 23 or the first tunnel lateral wall from dropping in first tunnel by first tunnel lateral wall, thereby avoid the junk to cause unexpected injury to the staff.

It should be noted that the length of the excavation may be the length of the body of the coal mining machine 3 to ensure that the coal mining machine 3 can smoothly enter the first gate way 1, for example, the length of the excavation may be 2m, and of course, other lengths may also be used as long as the coal mining machine 3 can be accommodated, which is not listed here. The excavation may be performed by the coal mining machine 3, or may be performed by other excavation devices, and is not particularly limited herein.

As shown in fig. 3, in step S120, a lead work is performed on the coal wall of the working face in the first gate way to form a lead work area.

The advancing operation can be carried out on the coal wall of the working face in the direction vertical to the working face in the first gate way 1, and an advancing working area 11 is formed. For example, blasting techniques may be used to blast the face coal wall in the first gate way 1 to create the look-ahead region 11. The length of blasting region can be controlled through reasonably setting the amount of blasting materials and the blasting angle, so that the advance working area 11 has a preset length, as shown in fig. 5, the advance working area 11 with the preset length can be used for accommodating a reversed loader and a belt conveyer, in an embodiment, the value range of the preset length can be 1.6 m-2.0 m, for example, 1.6m, 1.7m, 1.8m, 1.9m or 2.0m, and of course, other preset lengths can be provided as long as the reversed loader and the belt conveyer can be accommodated.

The waste rock 23 generated in the advanced operation process can be filled in the goaf 6 outside the side wall of the first gate way 1, zero waste rock 23 discharge on the working surface is realized, the transportation cost of the waste rock 23 can be eliminated, and the pollution of the waste rock 23 to the earth surface environment can be reduced to the maximum extent. Meanwhile, the waste rock 23 is filled in the goaf 6, the supporting force of the waste rock 23 can be utilized, the incoming pressure strength of the first roadway roof plate is reduced, the first crossheading 1 is easy to support, the supporting strength of the first roadway can be weakened appropriately, and the supporting cost is reduced.

In order to ensure the safety of the workers in the lead working area 11, the lead working area 11 may be supported to prevent the gangue 23 in the lead working area 11 from falling, and as shown in fig. 6, the lead working area 11 may be supported by a four-beam eight-column and tail beam support system 13. Four-beam eight-column and tail-beam supporting system 13 can include four supporting beams and eight supporting columns at least, and every supporting beam all can be supported by two supporting columns, and two supporting columns can be located a supporting beam's both ends respectively, can be used to support a supporting beam top on the roof of leading workspace 11, still can add the tail-beam as supporting at the tip of supporting beam in order to consolidate a supporting beam, in order to guarantee that leading workspace 11 roof can not drop, and then prevent that waste rock 23 from dropping, guarantee various machine normal work, guarantee staff's safety.

As shown in fig. 3, in step S130, coal is simultaneously extracted to both sides of the first gateway in a direction parallel to the working face in the lead working zone using a shearer, and the extracted coal is conveyed to a scraper conveyor.

The side wall of the advanced working area 11 can expose an extremely thin coal seam and a coal seam roof 17, so that coal mining work can be performed by the coal mining machine 3 in the advanced working area 11 in a manner of oblique cutting feed along a direction parallel to a working surface, and in order to improve the coal mining efficiency, two coal mining machines 3 can be used for simultaneously mining coal from the advanced working area 11 to two sides of the first gateway 1. The scraper conveyor 2 can be arranged on one side of the coal mining machine 3 far away from the coal wall of the working face, and can continuously move forwards along with the running state of the coal mining machine 3, so that the coal body mined by the coal mining machine 3 can fall onto the scraper conveyor 2 in real time, and the coal body can be conveniently conveyed out through the scraper conveyor 2 in real time. And the scraper conveyor 2 can be pushed to slide in real time at a certain distance from the coal mining machine 3 while the coal mining machine 3 mines coal, namely: the pushing and sliding process and the coal mining process of the coal mining machine 3 are carried out simultaneously, and the scraper conveyor 2 can push and slide at a corresponding distance at a position lagging behind the coal mining machine 3 by a certain distance when the coal mining machine 3 moves forward for a certain distance.

It should be noted that, pushing and sliding can be performed in the operation process of the scraper conveyor 2, and the pushing and sliding step can be a coal cutting step; the scraper conveyor 2 can be pushed and slid in the same direction, namely from the head to the tail or from the tail to the head.

As shown in fig. 5, a single support system 14 can be used to support the side of the coal mining machine 3 away from the coal wall of the working face in real time during the coal mining process of the coal mining machine 3, and the machine tracking and moving can be performed in real time according to the operation state of the coal mining machine 3. For example, during the operation of the coal mining machine 3, the single support system 14 may be used to support the excavation roadway of the coal mining machine 3 in real time at the side lagging the coal mining machine 3, so as to prevent the gangue 23 from falling off, and ensure that the excavation roadway can be reused during the back stepping process.

The individual support system 14 may include a plurality of support rods, each of which may be supported against the roof of the roadway to prevent the mine spoil 23 from falling off the top of the roadway. In one embodiment, the struts may be arranged side by side along the width direction of the excavation roadway, and each strut is added by one row for each forward heading of the shearer 3 by a predetermined distance, for example, the predetermined distance may be 5m, 6m, 7m, 8m, 9m, or 10m, or other predetermined distances, which are not listed herein.

In an embodiment, the transfer conveyor 21 may be disposed at the junction of the first roadway and the working surface, and a four-beam eight-column and tail beam supporting system may be used to support the junction of the first roadway and the working surface, so as to prevent the gangue 23 from dropping, ensure the normal operation of various machines, and ensure the safety of workers. The reversed loader 21 can be communicated with the end part of the scraper conveyor 2 and can be used for receiving the coal body conveyed by the scraper conveyor 2. Specifically, the transfer conveyor 21 may overlap the face scraper conveyor 2 at one end and may be connected to the tail of the belt conveyor at the other end, and may be used to transfer the coal bodies carried out by the scraper conveyor to the belt conveyor 22.

One end of the belt conveyor 22 may be connected to the reversed loader 21, and the other end of the belt conveyor may extend to a side away from the reversed loader 21 along the extending direction of the first gate way 1, and may extend to the outside of the first gate way 1, and may be used to convey the coal to the outside of the first gate way 1.

As shown in fig. 3, in step S140, when the coal mining machine located on one side of the first gate way runs to a first preset position, performing advanced blasting on the working face to form a second roadway, and supporting the second roadway to form a second gate way; and when the coal mining machine on the other side of the first crossheading runs to a second preset position, performing advanced blasting on the working face to form a third roadway, and supporting the third roadway to form a third crossheading.

As shown in fig. 7, when the coal mining machine 3 located on one side of the first gate way 1 moves to the first preset position 15, the blasting technology can be used to perform advanced roof-breaking blasting on the working face to form a tunnel space, a second tunnel can be formed after the working face is pushed, and meanwhile, the temporary support system 12 and the permanent support system can be used to support the side wall and the top of the second tunnel to form the second gate way 4, so as to prevent the gangue 23 from falling off and causing injury to workers.

When the coal mining machine 3 on the other side of the first gate way 1 runs to a second preset position, the blasting technology can be adopted to carry out advanced roof breaking blasting on the working face to form a tunnel space, a third tunnel can be formed after the working face is pushed, and meanwhile, a temporary supporting system 12 and a permanent supporting system can be adopted to temporarily support the side wall and the top of the third tunnel to form a third gate way 5, so that the gangue 23 is prevented from falling off and injuring workers. The details of the temporary support system 12 and the permanent support system are shown in detail in the support process of the first gateway 1 and will not be described herein.

In an embodiment, the distance between the first predetermined position 15 and the first gate way 1 may be equal to the distance between the second predetermined position and the first gate way 1, and the distance may be set according to actual engineering requirements. For example, the pitch may be 100m, 150m, 200m, 250m, or 300 m. Of course, the distance between the first predetermined position 15 and the first gate way 1 may not be equal to the distance between the second predetermined position and the first gate way 1, and is not limited herein. The second crossheading 4 and the third crossheading 5 can be used as ventilation channels, and can be used for ensuring good ventilation of the mine and avoiding single-head ventilation. The width of the second gate groove 4 may be equal to the width of the third gate groove 5, and may be smaller than the width of the first gate groove 1. For example, the widths of the second gate way 4 and the third gate way 5 may range from 2m to 3m, for example, they may be 2m, 2.2m, 2.4m, 2.6m, 2.8m or 3.0m, of course, the widths of the second gate way 4 and the third gate way 5 may be other widths, which are not listed here.

The side wall of the second gate way 4 far away from the first gate way 1 is a coal seam 16, a goaf 6 can be arranged between the second gate way and the first gate way 1, and waste rock 23 generated by advanced operation can be directly filled into the goaf 6 under the shield of the temporary support system 12 in the advanced operation process, so that zero waste rock 23 discharge on a working surface is realized, the transportation cost of the waste rock 23 is eliminated, the self-supporting force of the waste rock 23 can be utilized, the incoming pressure strength of a roadway roof is reduced, and the support cost of the roadway is reduced. The side wall of the first gate way 1 close to the goaf 6 can be sealed by adopting concrete 7, so that the gangue 23 is prevented from falling into the first gate way 1. Meanwhile, the side wall of the second gate way 4 close to the goaf 6 can be sealed by adopting the concrete 7, so that the gangue 23 is prevented from falling into the second gate way 4, and the safety of workers is guaranteed.

The side wall of the third crossheading 5, which is far away from the first crossheading 1, is a coal seam 16, a goaf 6 can be arranged between the first crossheading 1, and waste rocks 23 generated by the advance operation can be respectively filled into the goaf 6 between the first crossheading 1 and the second crossheading 4 and the goaf 6 between the first crossheading 1 and the third crossheading 5 under the shield of the temporary support system 12 in the advance operation process, so that zero waste rocks 23 on the working surface can be discharged, and the support cost of a roadway can be reduced. The side wall of the first gate way 1 close to the goaf 6 can be sealed by adopting concrete 7, so that the gangue 23 is prevented from falling into the first gate way 1. Meanwhile, the concrete 7 can be adopted to seal the side wall of the third crossheading 5 close to the goaf 6, so that the gangue 23 is prevented from falling into the third crossheading 5, and the safety of workers is guaranteed.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A method for longwall mining of an ultra-thin coal seam based on an N00 construction method is characterized by comprising the following steps:

2. The mining method of claim 1, wherein the supporting the first roadway to form a first gate way comprises:

3. The mining method of claim 1, further comprising:

4. The mining method of claim 1, further comprising:

5. A mining method as claimed in claim 1, wherein a goaf is between the first and second gate roads, the mining method further comprising:

6. A mining method as claimed in claim 1, wherein a goaf is between the first and third gate roads, the mining method further comprising:

7. The mining method of claim 1, wherein the advancing the coal wall of the face within the first gate way to form an advance work zone comprises:

8. The mining method according to claim 7, wherein the preset length is in a range of 1.6m to 2.0 m.

9. A mining method as claimed in claim 1, wherein the first predetermined location is spaced from the first gate by a distance equal to the second predetermined location.