Method for filling mining under thick coal seam of linear structure with protective coal pillar

Abstract

The application discloses a linear structure under thick coal seam protection coal pillar filling mining method and relates to the technical field of coal seam mining. The mining method comprises the following steps: firstly, determining the length of the thick coal seam protection coal pillar under the linear structure, the thickness of the limited thickness mining and the filling scheme; secondly, when the thick coal seam is fully mined to the left end of the protection coal pillar, the linear structure protection coal pillar is limited thickness mined, and the "throwing gangue + grouting" filling body is formed at the left end of the protection coal pillar; the working face continues to advance, and the paste body filling is carried out in the limited thickness mining goaf; then, the working face continues to advance, and the original gangue filling is carried out in the limited thickness mining goaf; the first two steps are repeated in sequence until the protection coal pillar is mined; finally, the protection coal pillar is limited thickness mined, a distance is continuously mined, the "throwing gangue + grouting" filling body is formed at the right end of the protection coal pillar, and the working face continues to advance after the filling body is connected. The application can maximize the liberation of the overburden coal resources under the linear structure and can improve the coal recovery rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal seam mining, in particular to a linear structure under thick coal seam protection coal pillar filling mining method. BACKGROUND

[0002] With the development of economic society, linear structures such as oil and gas pipelines develop rapidly and have to be arranged above coal mines, thereby causing linear structures to overlie a large amount of coal resources. Due to the long running distance and high deformation requirement of these structures, coal mining is more strict, and liberating coal resources under linear structures gradually becomes a problem of mine exploitation.

[0003] At present, the coal resources under linear structures are mainly mined by leaving a large protection coal pillar, which causes a large amount of coal resources to be wasted. SUMMARY

[0004] The present application aims to provide a linear structure under thick coal seam protection coal pillar filling mining method, which can maximize the liberation of coal resources under linear structures and improve the coal recovery rate.

[0005] In order to achieve the above-mentioned purpose, the main technical problem to be overcome by the present application is how to improve the coal recovery rate under linear structures.

[0006] In order to solve the above-mentioned technical problem, the present application adopts the following technical scheme:

[0007] A linear structure under thick coal seam protection coal pillar filling mining method, comprising the following steps in sequence:

[0008] a. determining the length of the linear structure under thick coal seam protection coal pillar, the thickness limit mining thickness, and the filling scheme;

[0009] b. when the thick coal seam is fully mined to the left end of the protection coal pillar, the linear structure protection coal pillar is limit-thickness mined, and a "gangue throwing + grouting" filling body is formed at the left end of the protection coal pillar;

[0010] c. the working face continues to advance, and the paste body filling is carried out in the limit-thickness mining goaf to form a paste body filling section;

[0011] d. the working face continues to advance, and the original gangue filling is carried out in the limit-thickness mining goaf to form an original gangue filling section;

[0012] e. steps c and d are repeated in sequence until the protection coal pillar is mined;

[0013] f. after the limit-thickness mining of the protection coal pillar is completed, the full-thickness mining is restored, and after a distance is continuously mined, a "gangue throwing + grouting" filling body is formed at the right end of the protection coal pillar; and the working face continues to advance after the filling body is connected to the top;

[0014] The width of the "throwing gangue + grouting" filling body formed at the left end and the right end of the protective coal pillar is equal, and is equal to the width of the working face;

[0015] The total length of the paste filling section and the original gangue filling section is equal to the length of the protective coal pillar, and the width of the paste filling section and the original gangue filling section is equal to the width of the working face;

[0016] The "throwing gangue + grouting" filling body at the left and right ends of the protective coal pillar and the paste filling section and the original gangue filling section jointly form a "Π" type structure.

[0017] In the step a of the linear structure under thick coal seam protective coal pillar filling mining method, the length of the linear structure under thick coal seam protective coal pillar is determined according to the length of the protected length, the coal seam strike direction base rock movement angle and the coal seam depth; the thickness of the limited thickness mining and the filling scheme are determined according to the coal seam geological conditions.

[0018] In the step b of the linear structure under thick coal seam protective coal pillar filling mining method, the isolation wall is built at the left end of the protective coal pillar and a distance away from the left end, a closed filling space is formed, the gangue is thrown into the filling space, the high water filling material is injected into the filling space through the grouting hole on the isolation wall after the filling space is filled with the gangue, and the "throwing gangue + grouting" filling body at the left end of the protective coal pillar is formed.

[0019] In the linear structure under thick coal seam protective coal pillar filling mining method, the length and the width of the paste filling section and the original gangue filling section are the same.

[0020] In the step c of the linear structure under thick coal seam protective coal pillar filling mining method, the isolation wall is built at the back of the working face of the limited thickness mining goaf by using the plastic woven cloth, a closed filling space is formed, and then the paste is filled in the filling space.

[0021] In the step d of the linear structure under thick coal seam protective coal pillar filling mining method, the isolation wall is built at the back of the working face of the limited thickness mining goaf by using the plastic woven cloth, a closed filling space is formed, and then the gangue is filled in the filling space.

[0022] In the linear structure under thick coal seam protective coal pillar filling mining method, the length of the protective coal pillar is L, which satisfies formula (1):

[0023]

[0024] In formula (1), a is the length of the protected length of the structure along the coal seam strike direction; α is the base rock movement angle in the coal seam strike direction; H is the coal seam depth;

[0025] The limited thickness mining thickness of the protective coal pillar is

[0026] Compared with the prior art, the present application has the following beneficial technical effects:

[0027] The present application provides a linear structure under thick coal seam protection coal pillar filling mining method, which fills the two ends of the linear structure and the goaf of limited thickness mining to form a "Π" type structure of the protection body, which can replace part of the pressure coal under the linear structure through the filling body while protecting the coal pillar, thereby improving the coal recovery rate.

[0028] Specifically, the goaf at both ends of the structure is filled by the "gangue throwing + grouting" method, and the goaf of limited thickness mining is filled by the "paste + original gangue" alternative filling method, and the overall "Π" type structure can transfer the stress concentration area generated at both ends of the protection coal pillar due to the bending and sinking of the main roof to both ends of the "gangue throwing + grouting" filling body, effectively reducing the influence of the movement of the overburden strata of the goaf on the protection coal pillar and the filling body structure in the protection coal pillar, further strengthening the protection of the linear structure on the ground, and the "Π" type structure is more stable, and part of the pressure coal under the structure can be replaced without being affected by mining.

[0029] The method can further consume the gangue in the mine, the two ends of the protection coal pillar are fully mined, and the goaf formed after mining is larger, so that the "gangue throwing + grouting" filling body arranged at both ends of the protection coal pillar can further consume the gangue in the mine, and better realize the green development of the mine.

[0030] Compared with the traditional coal mining method of setting a protection coal pillar to protect the surface structure, the present application replaces part of the pressure coal under the structure by limited thickness mining and alternative filling, improves the coal recovery rate, and reduces the waste of coal resources; the gangue grouting filling is performed at both ends of the linear structure protection coal pillar, and the paste + gangue alternative filling is performed in the protection coal pillar, which effectively limits the surface subsidence and protects the linear structure on the ground; the "gangue throwing + grouting" filling and the "paste + gangue" alternative filling are adopted, which reduces the filling cost, consumes the gangue in the mine, protects the ecological environment, and realizes the green development of the mine. BRIEF DESCRIPTION OF DRAWINGS

[0031] The present application will be further described below with reference to the accompanying drawings:

[0032] Figure 1 is a coal mining plan view of thick coal seam limited thickness mining alternative filling;

[0033] Figure 2 is a coal mining elevation view of thick coal seam limited thickness mining alternative filling;

[0034] In the drawings:

[0035] 1, "throwing gangue + grouting" filling body, 2, paste filling section, 3, original gangue filling section, 4, left end of protective coal pillar, 5, right end of protective coal pillar, 6, surface subsidence to transition zone, 7, linear structure, a, the length of the structure along the strike of the coal seam; b, the width of the "throwing gangue + grouting" filling body, c, the length of the "throwing gangue + grouting" filling body, d, the length of the paste filling section, e, the length of the original gangue filling section, alpha is the base rock movement angle in the direction of the strike of the coal seam; H is the coal seam depth; h, the thickness of the coal seam, L, the length of the protective coal pillar. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

[0037] The technical solutions of the present application will be further described in detail below with reference to the drawings.

[0038] In combination with Figure 1 and Figure 2 shown, the linear structure under thick coal seam protective coal pillar filling mining method proposed by the present application, wherein the protective coal pillar is located under the linear structure, the present application sets "throwing gangue + grouting" filling body 1 at the left end of the protective coal pillar 4 and the right end of the protective coal pillar 5, and alternately fills the paste and the original gangue in the mined-out area in sequence to form the paste filling section 2, the original gangue filling section 3, the paste filling section 2, the original gangue filling section 3…

[0039] Figure 1 and Figure 2 shown, the surface subsidence to transition zone 6, the linear structure 7, the length of the structure along the strike of the coal seam a, the width of the "throwing gangue + grouting" filling body b, the length of the "throwing gangue + grouting" filling body c, the length of the paste filling section d, the length of the original gangue filling section e, the base rock movement angle in the direction of the strike of the coal seam alpha, the coal seam depth H, the thickness of the coal seam h, and the length of the protective coal pillar L.

[0040] The linear structure under thick coal seam protective coal pillar filling mining method proposed by the present application has the following specific steps:

[0041] The method comprises the following steps:

[0042] Step one, determining the length of the protective coal pillar under the linear structure, the thickness of the limited thickness mining, and the filling scheme; determining the length of the protective coal pillar under the linear structure according to the length of the protective coal pillar, the base rock movement angle in the direction of the strike of the coal seam, and the coal seam depth; determining the thickness of the limited thickness mining and the filling scheme according to the coal seam geological conditions;

[0043] Step two, when the thick coal seam is fully mined to the left end of the protective coal pillar, the linear structure of limited thickness mining is constructed to protect the coal pillar, and a "gangue + grouting" filling body is formed at the left end of the protective coal pillar; an isolation wall is built at the left end of the protective coal pillar and a distance away from the left end, a closed filling space is formed, and then the filling space is filled with gangue, and then high-water filling material is injected into the filling space through the grouting hole on the isolation wall to form a "gangue + grouting" filling body at the left end of the protective coal pillar.

[0044] Step three, the working face continues to advance, and the paste body filling is carried out in the limited thickness mining goaf to form a paste body filling section; the isolation wall is constructed with the plastic woven cloth behind the working face of the limited thickness mining goaf to form a closed filling space, and then the paste body filling is carried out in the filling space.

[0045] Step four, the working face continues to advance, and the original gangue filling is carried out in the limited thickness mining goaf to form an original gangue filling section; the isolation wall is constructed with the plastic woven cloth behind the working face of the limited thickness mining goaf to form a closed filling space, and then the gangue filling is carried out in the filling space.

[0046] Step five, steps three and four are repeated in turn until the protective coal pillar is mined out;

[0047] Step six, after the limited thickness mining of the protective coal pillar is completed, the full thickness mining is resumed, and after a distance of mining is continued, a "gangue + grouting" filling body is formed at the right end of the protective coal pillar; the working face continues to advance after the filling body is connected to the top;

[0048] The width of the "gangue + grouting" filling body formed at the left end and the right end of the protective coal pillar is equal, and both are the width of the working face;

[0049] The total length of the paste body filling section and the original gangue filling section is equal to the length of the protective coal pillar, and the width of the paste body filling section and the original gangue filling section is the width of the working face;

[0050] The "gangue + grouting" filling bodies at the left and right ends of the protective coal pillar and the paste body filling section and the original gangue filling section together form a "Π" type structure.

[0051] Suppose the length of the protective coal pillar is L, which satisfies formula (1):

[0052]

[0053] In formula (1), a is the length of the structure along the strike of the coal seam; α is the base rock movement angle in the strike direction of the coal seam; H is the burial depth of the coal seam;

[0054] The limited thickness mining thickness of the protective coal pillar is

[0055] The following will be further described in combination with specific embodiments:

[0056] Example 1

[0057] The specific steps are:

[0058] Step one: according to the length of the protected length, the direction of the coal seam, the base rock movement angle and the depth of the coal seam, the length of the structure protection coal pillar is determined. According to the geological conditions of the coal seam, the thickness of the limited mining, the length of the gangue + grouting filling body, the length of the paste filling section and the length of the original gangue filling section are determined.

[0059] Step two: after the full thickness mining of the thick coal seam to the left end of the protection coal pillar, the linear structure protection coal pillar is limited to thickness mining, and the isolation wall is built at the left end and c meters away from the left end of the protection coal pillar.

[0060] Step three: after forming a closed filling space, the filling space is filled with gangue, and after the filling space is filled with gangue, high water filling material is injected into the filling space through the grouting hole on the isolation wall. After the filling is connected to the top, the working face continues to advance.

[0061] Step four: after the working face continues to advance d meters, the length of the paste filling section is reached, and the isolation wall is built behind the working face with plastic woven cloth to form a closed filling space. Then, the filling space is filled with paste. After the filling is connected to the top, the working face continues to advance.

[0062] Step five: after the working face continues to advance e meters, the length of the original gangue filling section is reached, and the isolation wall is built behind the working face with plastic woven cloth to form a closed filling space. Then, the filling space is filled with gangue. After the filling space is filled with gangue, the working face continues to advance.

[0063] Step six: repeat steps four and five until the linear structure protection coal pillar is mined.

[0064] Step seven: after the limited thickness mining of the protection coal pillar, the full thickness mining is resumed, and after c meters of mining, the length of the gangue + grouting filling body is reached, and the isolation wall is built behind the working face.

[0065] Step eight: after forming a closed filling space, the filling space is filled with gangue, and after the filling space is filled with gangue, high water filling material is injected into the filling space through the grouting hole on the isolation wall. After the filling is connected to the top, the working face continues to advance.

[0066] Comparative Example 1

[0067] The difference between Example 1 and Comparative Example 1 is:

[0068] The structure of "gangue + grouting" filling body is not used at the left and right ends of the protection coal pillar.

[0069] Comparison of the effects of Example 1 and Comparative Example 1:

[0070] The embodiment 1 further strengthens the protection of the linear ground structure. The coal pillar ends are both located at the position of the coal seam strike bedrock movement angle, which is the key to the deformation of the protected ground. The structure of the "gangue throwing + grouting" filling body at the two ends of the coal pillar can make it and the coal pillar and the filling body at the two ends of the coal pillar jointly play a supporting role, further limit the deformation and sinking of the protected ground, and strengthen the protection of the boundary of the linear ground structure.

[0071] Those skilled in the art should understand that the above embodiments are only used to illustrate the present application, and are not used as limitation to the present application, and any appropriate changes and variations made to the above embodiments within the spirit and principle of the present application fall within the scope of the present application.

Claims

1. A method for the filling mining of a protective coal pillar in a thick coal seam under a linear structure, characterized in that, The steps include the following in sequence: a. determining the length of the protective coal pillar under the linear structure, the thickness-limited mining thickness of the thick coal seam, and the filling scheme; b. when the thick coal seam is fully mined to the left end of the protective coal pillar, the protective coal pillar is thickness-limited mined, and a "gangue throwing + grouting" filling body is formed at the left end of the protective coal pillar; c. the working face continues to advance, and the paste body filling is carried out in the thickness-limited mining goaf to form a paste body filling section; d. the working face continues to advance, and the original gangue filling is carried out in the thickness-limited mining goaf to form an original gangue filling section; e. steps c and d are repeated in sequence until the protective coal pillar is mined out; f. after the protective coal pillar is fully mined, the full-thickness mining is resumed, and after a distance of continuous mining, a "gangue throwing + grouting" filling body is formed at the right end of the protective coal pillar; the working face continues to advance after the filling body is connected; The width of the "gangue throwing + grouting" filling bodies formed at the left and right ends of the protective coal pillar is equal, and is equal to the width of the working face; The total length of the paste body filling section and the original gangue filling section is equal to the length of the protective coal pillar, and the width of the paste body filling section and the original gangue filling section is equal to the width of the working face; The "gangue throwing + grouting" filling bodies at the left and right ends of the protective coal pillar and the paste body filling section and the original gangue filling section together form a "Π" type structure.

2. The method according to claim 1, characterized in that: In step a, the length of the protective coal pillar under the linear structure is determined according to the length of the protected length, the coal seam strike direction bedrock movement angle and the coal seam depth; the thickness-limited mining thickness and the filling scheme are determined according to the coal seam geological conditions.

3. The method according to claim 1, characterized in that: In step b, an isolation wall is built at the left end of the protective coal pillar and a distance away from the left end to form a closed filling space, and then the filling space is thrown with gangue; after the filling space is filled with gangue, high-water filling material is injected into the filling space through the grouting hole on the isolation wall to form a "gangue throwing + grouting" filling body at the left end of the protective coal pillar.

4. The method according to claim 1, characterized in that: The length and width of the paste body filling section and the original gangue filling section are the same.

5. The method according to claim 1, characterized in that: In step c, an isolation wall is built behind the working face of the thickness-limited mining goaf with plastic woven cloth to form a closed filling space, and then the filling space is filled with paste.

6. The method according to claim 1, characterized in that: In step d, an isolation wall is built behind the working face of the thickness-limited mining goaf with plastic woven cloth to form a closed filling space, and then the filling space is filled with gangue.

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