阅读说明：本技术 一种沿空留巷采空区分次充填开采装置及其方法 (Gob-side entry retaining gob graded filling mining device and method thereof ) 是由 顾伟 黎勇 宋刚 冯鑫 郭宁 于 2021-08-03 设计创作，主要内容包括：本发明涉及一种沿空留巷采空区分次充填开采装置及其方法,属于煤炭开采的技术领域,解决了现有技术中工作面的推进速度低和大量煤矸石等固定废物堆积的问题。本发明提供一种沿空留巷采空区分次充填开采装置,包括多个液压支架、多个注浆连管、多个注浆袋和采空区；注浆连管安装在液压支架的掩护梁上；掩护梁的两侧边对称设有支撑组件,支撑组件可向上或向下转动。本发明利用液压支架留设注浆袋,形成采空区的阻挡墙,在采空区注浆的同时可进行开采,缩短工程时间,提升开采效率。(The invention relates to a gob-side entry retaining gob graded filling mining device and a gob-side entry retaining gob graded filling mining method, belongs to the technical field of coal mining, and solves the problems that the advancing speed of a working face is low and a large amount of fixed wastes such as coal gangue are accumulated in the prior art. The invention provides a gob-side entry retaining gob graded filling mining device, which comprises a plurality of hydraulic supports, a plurality of grouting connecting pipes, a plurality of grouting bags and a gob; the grouting connecting pipe is arranged on a shield beam of the hydraulic support; and the two side edges of the shield beam are symmetrically provided with supporting components which can rotate upwards or downwards. According to the invention, the grouting bags are reserved on the hydraulic support to form the blocking wall of the goaf, so that the goaf can be exploited while grouting, the engineering time is shortened, and the exploitation efficiency is improved.)

1. A gob-side entry retaining gob graded filling mining device is characterized by comprising a plurality of hydraulic supports (1), a plurality of grouting connecting pipes (2), a plurality of grouting bags (3) and a gob (4);

the grouting connecting pipe (2) is arranged on a shield beam (11) of the hydraulic support (1) and is used for grouting into the grouting bag (3);

two side edges of the shield beam (11) are symmetrically provided with supporting components which can rotate upwards or downwards;

the grouting bag (3) is sleeved on the supporting component, and the supporting component rotates upwards to drive the grouting bag (3) to be parallel to the supporting beam (14) of the hydraulic support (1);

the hydraulic support (1) is lowered and moves forwards, meanwhile, the support component rotates downwards, and a grouting bag (3) for completing grouting is separated from the support component, so that a blocking wall of the goaf (4) is formed.

2. A gob-side entry retaining gob fractional filling mining apparatus according to claim 1 wherein the support assembly includes a first support bar (12), the first support bar (12) being hinged at one end to the top end of the shield beam (11).

3. A gob-side entry retaining gob fractional filling mining apparatus according to claim 2 wherein the support assembly further comprises a second support bar (13), the second support bar (13) being hingedly connected at one end to the first support bar (12) and slidably connected at the other end to the shield beam (11).

4. A gob-side entry retaining gob fractional filling mining apparatus according to claim 2 wherein the grouting bag (3) is provided with a grommet (31), the grommet (31) fitting over the first support bar (12).

5. The gob-side entry retaining gob fractional filling mining apparatus according to claim 1, further comprising a first gangue bag wall (5).

6. The gob-side entry retaining gob fractional filling mining apparatus according to claim 1 further comprising a second gangue bag wall (8).

7. The gob-side entry retaining gob fractional filling mining apparatus according to claim 1 further comprising a concrete pillar (6).

8. A gob-side entry retaining gob fractional filling mining apparatus according to claim 7 further comprising a flexible pad layer (7), the flexible pad layer (7) being disposed above the concrete column (6).

9. A gob-side entry retaining gob fractional cut-fill mining method according to any one of claims 1 to 8, characterized by the steps comprising:

step 1: mounting the support assembly and the grouting connecting pipe (2) on a hydraulic support (1), and enabling the hydraulic support (1) to move forwards along with a coal mining machine to form a first transportation lane (100) and a second transportation lane (200);

step 2: when the hydraulic support (1) is lifted, the grommet (31) of the grouting bag (3) is sleeved on the support component, and grouting liquid is injected into the grouting bag (3) by the grouting connecting pipe (2), and when the hydraulic support (1) is lowered, the grouting bag (3) forms a barrier wall;

and step 3: a first gangue bag wall (5), a second gangue bag wall (8) and a concrete pillar (6) are piled up;

and 4, step 4: grouting the goaf (4), and simultaneously lifting the hydraulic support (1) to mine forwards;

and 5: pouring the first pouring layer (51) and the second pouring layer (81);

step 6: and (5) repeating the steps 1-5 until the mining of the working face is finished.

10. The gob-side entry retaining gob fractional filling mining method according to claim 9, wherein the first gangue bag wall (5), the barrier wall formed by the grouting bag (3), the second gangue bag wall (8) and the rock wall in step 3 jointly form a gob (4) closed space.

Technical Field

The invention relates to the technical field of coal mining, in particular to a gob-side entry retaining gob graded filling mining device and a gob-side entry retaining gob graded filling mining method.

Background

Currently, the 'three next to one up' coal pressing of Chinese coal mines is common, and according to incomplete statistics of key coal mines in China, the national coal pressing amount is about 137.9 hundred million tons, but the coal pressing amount mined is very small and is less than 7 percent of the total coal pressing amount. And a large amount of solid wastes such as coal gangue are generated by long-term coal mining, the current coal gangue accumulated nationwide is about 45 hundred million tons, and the accumulation of a large amount of coal gangue causes great pollution to the surrounding environment of a mining area. Under the condition of safety and economy, the processing of exploiting 'third-time coal pressing' and coal gangue is a problem which needs to be solved urgently at present in coal mines.

Gob-side entry retaining coal pillar-free mining is one of the main approaches for solving the current coal resource waste, and filling gangue into a goaf is a main approach for treating solid wastes such as coal gangue and the like. However, after grouting in a goaf is finished in the conventional coal mine gob-side entry retaining filling mining, coal mining can be pushed forward only after slurry is solidified, so that the stoping efficiency of a working face is greatly influenced, and the pushing speed of the working face is greatly reduced.

Disclosure of Invention

In view of the above analysis, the embodiment of the present invention aims to provide a gob-side entry retaining goaf fractional filling mining device and a method thereof, so as to solve the problems that coal mining can be advanced only after slurry is solidified after grouting of a gob in existing coal mine gob-side entry retaining filling mining is completed, so that the advancing speed of a working face is greatly reduced, and coal gangue is treated.

The invention provides a gob-side entry retaining gob graded filling mining device, which comprises a plurality of hydraulic supports, a plurality of grouting connecting pipes, a plurality of grouting bags and a gob;

the grouting connecting pipe is arranged on a shield beam of the hydraulic support and is used for grouting into the grouting bag;

the two side edges of the shield beam are symmetrically provided with supporting components which can rotate upwards or downwards;

the grouting bag is sleeved on the supporting component, and the supporting component rotates upwards to drive the grouting bag to be parallel to the supporting beam of the hydraulic support;

the hydraulic support (1) is lowered and moves forwards, meanwhile, the support component rotates downwards, and a grouting bag for completing grouting is separated from the support component, so that a blocking wall of the goaf is formed.

Optionally, the support assembly comprises a first support bar, one end of which is hinged to the top end of the shield beam.

Optionally, the support assembly further comprises a second support rod, one end of the second support rod is hinged to the first support rod, and the other end of the second support rod is connected with the shield beam in a sliding mode.

Optionally, the grouting bag is provided with a grommet, and the grommet is sleeved on the first support rod.

Optionally, a first mine waste bag wall is also included.

Optionally, a second mine waste bag wall is also included.

Optionally, a concrete column is also included.

Optionally, the concrete column further comprises a flexible cushion layer, wherein the flexible cushion layer is arranged above the concrete column.

The invention also provides a gob-side entry retaining gob graded filling mining method, which comprises the following steps:

step 1: mounting the support assembly and the grouting connecting pipe on a hydraulic support, and enabling the hydraulic support to move forwards along with the coal mining machine to form a first transportation lane and a second transportation lane;

step 2: when the hydraulic support is lifted, a grommet of the grouting bag is sleeved on the support assembly, and grout is injected into the grouting bag by using the grouting connecting pipe;

and step 3: stacking a first gangue bag wall, a second gangue bag wall and a concrete pillar;

and 4, step 4: grouting the goaf, and simultaneously lifting the hydraulic support to mine forwards;

and 5: pouring the first pouring layer and the second pouring layer;

step 6: and (5) repeating the steps 1-5 until the mining of the working face is finished.

Optionally, in the step 3, the first gangue bag wall, the blocking wall formed by the grouting bag, the second gangue bag wall and the rock wall form a goaf closed space together.

Compared with the prior art, the invention can realize at least one of the following beneficial effects:

1. according to the invention, the grouting bags are reserved on the hydraulic support to form the blocking wall of the goaf, so that slurry in the goaf can be blocked, and mining can be carried out while grouting is carried out on the goaf, thus solving the problem of mining-filling contradiction in the prior art, shortening the engineering time and improving the mining efficiency.

2. The invention adopts a fractional filling method, namely, slurry is injected into the grouting bag firstly, and then slurry is injected into the goaf, so that the mining efficiency is increased, and the resource recovery rate of 'three next to one top' coal pressing is improved.

3. The invention adopts gob-side entry retaining non-pillar mining, reduces the loss of pillars and increases the resource recovery rate of coal.

4. According to the invention, the first gangue bag wall and the second gangue bag wall both adopt gangue, the gangue is recycled, the problem of accumulation of coal gangue and fly ash solid wastes is solved, and the environmental pollution caused by coal mining is reduced; and the first gangue bag wall and the second gangue bag wall support a top plate of the goaf together, so that the stability of the goaf is ensured.

5. The invention reserves the first gangue bag wall for the next-stage mining, accelerates the project progress and provides the mining efficiency.

6. According to the invention, the grommet is designed on the grouting bag, and when the hydraulic support is lifted, the grommet is sleeved on the first support rod; along with hydraulic support frame and forward movement, the grommet just can drop from first bracing piece, and grommet simple structure, this process operation is simple and convenient and high-efficient.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic view of a gob-side entry retaining gob graded filling mining process of the present invention;

FIG. 2 is a schematic diagram of the arrangement of the hydraulic support and the grouting bag of the present invention;

FIG. 3 is a schematic cross-sectional view of a first haulage roadway according to the present invention;

FIG. 4 is a schematic cross-sectional view of a second haulage roadway according to the present invention;

fig. 5 is a schematic structural diagram of a hydraulic bracket and a support assembly according to the present invention.

Reference numerals:

1-a hydraulic support; 11-a shield beam; 12-a first support bar; 13-a second support bar; 14-a support beam; 2-grouting connecting pipes; 3-grouting bags; 31-a grommet; 4-a goaf; 5-a first gangue bag wall; 51-a first casting layer; 6-concrete columns; 7-a flexible cushion layer; 8-a second gangue bag wall; 81-a second casting layer; 91-a first grouting pump; 92-a first slip casting pipe; 93-first grouting holes; 94-second grouting pump; 95-a second slip casting pipe; 96-second grouting hole; 100-a first lane; 200-second lane.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

Example 1

The invention discloses a gob-side entry retaining goaf fractional filling mining device, which comprises a plurality of hydraulic supports 1, a plurality of grouting connecting pipes 2, a plurality of grouting bags 3 and a goaf 4, wherein the grouting connecting pipes 2 are arranged on a shield beam 11 of the hydraulic supports 1 and are used for grouting the grouting bags 3; the two side edges of the shield beam 11 are symmetrically provided with supporting components which can rotate upwards or downwards; the grouting bag 3 is sleeved on the supporting component, the supporting component rotates upwards to drive the grouting bag 3 to rise to be parallel to the supporting beam 14 of the hydraulic support 1, and the grouting connecting pipe 2 is used for grouting into the grouting bag 3; the hydraulic support falls down and moves forwards, and meanwhile, the support component moves downwards, and the grouting bag 3 for completing grouting is separated from the support component, so that a blocking wall of the goaf 4 is formed.

In the embodiment, the grouting bag 3 is reserved on the hydraulic support 1 to form a blocking wall of the goaf 4, so that the slurry in the goaf 4 can be blocked, the goaf 4 can be grouted and mined simultaneously, the problem of the contradiction of mining and filling in the prior art is solved, namely, when the goaf is filled with the slurry, the goaf can be mined only after the slurry is solidified, so that the slurry flow is prevented from influencing the coal mining work; the invention adopts a fractional filling method, namely, slurry is injected into the grouting bag firstly, and then slurry is injected into the goaf, so that the mining efficiency is increased, and the resource recovery rate of 'three next and one top' coal pressing is improved; the invention adopts gob-side entry retaining non-pillar mining, reduces the loss of pillars and increases the resource recovery rate of coal.

Specifically, the specific number of the hydraulic supports 1, the grouting connecting pipes 2 and the grouting bags 3 is determined according to the actual situation, and the hydraulic supports 1, the grouting connecting pipes 2 and the grouting bags 3 are in one-to-one correspondence; before the working face begins to recover, a grouting connecting pipe 2 is arranged on a shield beam 11 of a hydraulic support 1, the grouting connecting pipe 2 is hinged with the shield beam 11, and the angle of the grouting connecting pipe 2 can be adjusted according to the position of a grouting bag 3.

The supporting component comprises a first supporting rod 12, one end of the first supporting rod 12 is hinged with the top end of the shield beam 11, the first supporting rod 12 can rotate around the hinged point, the grouting bag 3 is provided with a grommet 31 matched with the first supporting rod 12, in the embodiment, 4 grommets are arranged, and 2 adjacent grommets 31 are sleeved on the front and back positions of the same first supporting rod 12; when the first support rod 12 rotates downwards, the grommet 31 of the grouting bag 3 is sleeved on the first support rod 12, and then the first support rod 12 rotates upwards to be parallel to the support beam 14, so that the opening of the grouting bag 3 is opened, and the grouting connecting pipe 2 is favorable for grouting into the grouting bag 3.

In this embodiment, a grommet 31 is designed on the grouting bag 3, and when the hydraulic support 1 is lifted, the grommet 31 is sleeved on the first support rod 12; as the hydraulic support 1 descends and moves forwards, the grommet 31 can fall off from the first support rod 12, the grommet 3 has a simple structure, and the operation of the process is simple, convenient and efficient.

Optionally, the grout in the grouting bag 3 is quick-setting grout, and can be solidified within 20 minutes, so that the grouting bag 3 has self-stability rapidly.

The support assembly further comprises a second support rod 13, wherein the second support rod 13 is used for driving the first support rod 12 to rotate, and when the first support rod 12 rotates to be parallel to the support beam 14, the second support rod 13 fixedly supports the first support rod 12.

In this embodiment, one end of the second support rod 13 is hinged to the first support rod 12, the other end of the second support rod is connected to the shield beam 11 in a sliding manner, specifically, a sliding groove is formed in the shield beam 11, a sliding block is arranged on the second support rod 13 and slides on the sliding groove, a limiting clamping groove is formed in two sides of the top end of the sliding groove, a limiting clamping strip matched with the limiting clamping groove is arranged on two sides of the sliding block, when the sliding block slides to the top end of the sliding groove, the limiting clamping strip is matched and fixed with the limiting clamping groove, the second support rod 13 is fixed to the top end of the sliding groove, and at the moment, the first support rod 12 is parallel to the support beam 14. .

The device also comprises a first waste rock bag wall 5 and a second waste rock bag wall 8, wherein the first waste rock bag wall 5, the grouting bag 3, the second waste rock bag wall 8 and the rock wall form a closed space of the goaf 4, and then the goaf is filled with slurry. Specifically, the first gangue bag wall 5 is arranged on the left side of the gob 4 to block the left side of the gob 4, namely the first transportation lane 100, but the first transportation lane 100 is not blocked for the next-stage mining; the second gangue bag wall 8 is horizontally arranged on the right side of the grouting bag 3, and plugs the upper side of the goaf 4 together with the grouting bag 3, and simultaneously plugs the second transportation lane 200.

According to the invention, the first waste rock bag wall 5 and the second waste rock bag wall 8 both adopt waste rocks, so that the waste rocks are recycled, the problem of accumulation of coal gangue and fly ash solid wastes is solved, and the environmental pollution caused by coal mining is reduced; the first gangue bag wall 5 is reserved for the next-stage recovery, so that the project progress is accelerated, and the recovery efficiency is improved; the first gangue bag wall 5 and the second gangue bag wall 8 support a top plate of the goaf together, and stability of the goaf is guaranteed.

In order to fill the gap between the first gangue bag wall 5 and the second gangue bag wall 8 and enhance the strength of the gap, a first pouring layer 51 and a second pouring layer 81 are paved on the outer layers of the first gangue bag wall 5 and the second gangue bag wall 8, and the first pouring layer 51 and the second pouring layer 81 are both formed by pouring concrete slurry.

It should be noted that, because the first gangue bag wall 5 needs to be reserved for the mining at the next stage, in order to ensure the stability of the top plate of the first transportation lane 100, a plurality of concrete columns 6 and flexible cushion layers 7 are arranged on the left side of the first gangue bag wall 5, and gaps are formed among the concrete columns 6 for grouting into the goaf 4; the flexible cushion layer 7 is arranged between the concrete upright 6 and the top plate of the first transportation lane 100 to relieve the pressure of the top plate; the flexible cushion layer 7 can be a gangue bag or a wood block and other substances with a buffering effect.

The apparatus further comprises a first grouting pump 91, a first grouting pipe 92 and a first grouting hole 93, the first grouting pump 91 is placed on the left side of the concrete column 6 in the open space area of the first haulage roadway 100; the first grouting hole 93 is formed in the first gangue bag wall 5; the first grouting pipe 92 is connected with a first grouting pump 91, penetrates through a gap between the concrete columns 6, and injects grout into the gob 4 through a first grouting hole 93; the system also comprises a second grouting pump 94, a second grouting pipe 95 and a second grouting hole 96, wherein the second grouting pump 94 is arranged above the second gangue bag wall 8 and in the open area of the second transportation roadway 200; and a second grouting hole 96 is formed in the second gangue bag wall 8, a second grouting pipe 95 is connected with a second grouting pump 94, and grout is injected into the gob 4 through the second grouting hole 96.

In the embodiment, the slurry is injected into the grouting bag 3 firstly, then the slurry is injected into the gob 4, and the gob 4 can be simultaneously injected with the slurry and can be mined forwards along the working face, so that the method for filling the gob in different times is beneficial to improving the coal mining efficiency and solving the existing mining and filling contradiction.

In this embodiment, the grout is injected into the gob 4 through the first grouting pump 91 and the second grouting pump 94 at the same time, so that the engineering time can be shortened; the shape of the first and second grout holes 93 and 96 is not limited, and preferably, the shape is a sector, which prevents the grout holes from being clogged during grouting and ensures uniform distribution of grout.

Further, the number of the first grouting pump 91, the first grouting pipe 92, the first grouting hole 93, the second grouting pump 94, the second grouting pipe 95, and the second grouting hole 96 is not limited, and is set according to the actual situation.

Example 2

According to the embodiment 1, the method for filling and mining gob sides with the gob-side entry retaining gob in the different times comprises the following steps:

step 1: mounting the support assembly and the grouting connecting pipe 2 on a hydraulic support 1, and enabling the hydraulic support 1 to move forwards along with a coal mining machine to form a first transportation lane 100 and a second transportation lane 200;

step 2: when the hydraulic support 1 is lifted, the grommet 31 of the grouting bag 3 is sleeved on the support component, and the grouting connecting pipe 2 is used for injecting grout into the grouting bag 3, and when the hydraulic support 1 is lifted, the grouting bag 3 forms a barrier wall;

and step 3: a first gangue bag wall 5, a second gangue bag wall 8 and a concrete pillar 6 are piled up;

and 4, step 4: grouting into the goaf 4, and simultaneously mining forwards by lifting the hydraulic support 1L;

and 5: pouring the first pouring layer 51 and the second pouring layer 81;

step 6: and (5) repeating the steps 1-5 until the mining of the working face is finished.

The specific contents are as follows:

in the step 1, before the stoping of the working face is started, one end of a first support rod 12 is arranged on the top end of a shield beam 11 of a hydraulic support 1 and is hinged with the shield beam 11; one end of a second support rod 13 is hinged with the first support rod 12, the other end of the second support rod is connected with the shield beam 11 in a sliding mode, a sliding groove needs to be formed in the shield beam 11, a sliding block matched with the sliding groove is arranged on the second support rod 13, a limiting clamping groove is formed in the top end of the sliding groove, and a limiting clamping strip fixed with the limiting clamping groove is arranged on the sliding block; a grouting connecting pipe 2 is arranged on the shield beam 11;

the working face begins to be mined, the hydraulic support 1 moves along with the coal mining machine as the coal mining machine cuts forward along the cutting hole, and the first transportation lane 100 and the second transportation lane 200 are formed after the working face is pushed forward for a certain distance.

In the step 2, after the working surface is pushed forward for a certain distance, in order to avoid the collapse of the goaf, the goaf needs to be grouted; firstly, sleeving a grommet 31 of a grouting bag 3 on a first support rod 12 of a support assembly, lifting the hydraulic support, enabling the first support rod 12 to rotate upwards to be parallel to a support beam 14, supporting and fixing the first support rod 12 by a second support rod 13 at the moment, opening an opening of the grouting bag 3, and grouting into the grouting bag 3 by using a grouting connecting pipe 2; after grouting is completed, the hydraulic support is moved forwards while descending the support, and meanwhile the first support rod 12 and the second support rod 13 rotate downwards, the first support rod 12 forms an inclined and previously moved state, so that the grommet 31 can be automatically separated from the first support rod 12, and the grouting bag 3 subjected to grouting is separated from the first support rod 12 to form a barrier wall of the goaf 4; then, the limiting clamping strip is separated from the limiting clamping groove manually, the second supporting rod 13 slides downwards, the first supporting rod 12 is driven to rotate downwards, the first supporting rod 12 inclines, the grouting bag 3 for next use is sleeved on the first supporting rod 12, along with the lifting of the hydraulic support 1, the first supporting rod 12 rotates upwards to be parallel to the supporting beam 14, the first supporting rod 12 is supported and fixed by the second supporting rod 13, the opening of the grouting bag 3 is opened, and grouting is performed into the grouting bag 3 through the grouting connecting pipe 2 for next use.

In the step 3, a first waste rock bag wall 5 is piled up at the left side of the goaf 4, and at the moment, the gap between the first waste rock bag wall 5 and the grouting bag 3 is sealed; a second gangue bag wall 8 is piled up on the right side of the grouting bag 3, the second gangue bag wall and the grouting bag 3 together block the upper side of the gob 4, and meanwhile, a second transportation lane 200 is blocked; the first gangue bag wall 5 and the second gangue bag wall 8 support a top plate of the goaf together, and stability of the goaf is guaranteed.

Set up a plurality of concrete columns 6 and flexible bed course 7 on the left of first waste bag wall 5, flexible bed course 7 sets up between concrete column 6 and first haulage way 100's roof, and concrete column 6 guarantees that first haulage way 100's roof is stable, and in the working face forward propulsion, leaves first haulage way 100, supplies the lower stage to adopt the use.

The first gangue bag wall 5, a blocking wall formed by the grouting bag 3, the second gangue bag wall 8 and the rock wall jointly form a closed space of the gob 4.

In step 4, digging a first grouting hole 93 and a second grouting hole 96 on the first waste rock bag wall 5 and the second waste rock bag wall 8; the first grouting pump 91 is placed on the left side of the concrete column 6, in the open area of the first haulage roadway 100; the second grouting pump 94 is arranged above the second sack wall 8 in the open space region of the second haulage roadway 200.

The first grouting pipe 92 is connected with a first grouting pump 91, penetrates through a gap between the concrete columns 6, and injects grout into the gob 4 through a first grouting hole 93; the second grouting pipe 95 is connected to a second grouting pump 94, injects the slurry into the gob 4 through a second grouting hole 96, and can be mined forward along the face while injecting the slurry into the gob 4.

In the step 5, after the grouting of the gob 4 is completed, a first pouring layer 51 and a second pouring layer 81 are laid on the outer layers of the first gangue bag wall 5 and the second gangue bag wall 8, and the first pouring layer 51 and the second pouring layer 81 are both formed by pouring concrete grout.

In step 6, the grouting bags 3 are arranged according to the cutting length of the actual coal mining machine, in the embodiment, the grouting bags 3 are reserved after the coal mining machine cuts 2-3 cutters forwards, and the steps 1-5 are continuously repeated until the mining of the working face is completed.

The invention has the following beneficial effects:

1. according to the invention, the grouting bag is reserved on the hydraulic support to form the blocking wall of the goaf, so that slurry in the goaf can be blocked, and therefore, the goaf can be mined while grouting is carried out, and the problem of mining and filling contradiction in the prior art is solved.

2. The invention adopts a fractional filling method, namely, slurry is injected into the grouting bag firstly, and then slurry is injected into the goaf, so that the mining efficiency is increased, and the resource recovery rate of 'three next to one top' coal pressing is improved.

3. The invention adopts gob-side entry retaining non-pillar mining, reduces the loss of pillars and increases the resource recovery rate of coal.

4. According to the invention, the first gangue bag wall and the second gangue bag wall both adopt gangue, the gangue is recycled, the problem of accumulation of coal gangue and fly ash solid wastes is solved, and the environmental pollution caused by coal mining is reduced; and the first gangue bag wall and the second gangue bag wall support a top plate of the goaf together, so that the stability of the goaf is ensured.

5. The invention reserves the first gangue bag wall for the next-stage mining, accelerates the project progress and provides the mining efficiency.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.