Rapid filling mining method for shallow seam

Abstract

The application discloses a kind of shallow coal seam rapid filling mining method, comprising the following steps: in the sequence of existing equipment in working face, special chute is arranged, and special chute is connected with the operation channel of at least two working face operation space and rear goaf of hydraulic support on working face;Along the working face, set up filling wall construction area between the two adjacent operation channels, and fill the filling paste into the filling wall construction area in goaf through the operation channel, and form multiple filling walls in goaf, which are discontinuously arranged along the working face;Unfilled area between adjacent filling walls is interconnected to form a continuous filling space, and the interval distance between filling wall and adjacent filling wall is a preset distance;Grouting hole is set on the ground in unfilled area, and filling slurry is injected into filling space, and filling slurry flows in filling space to complete the overall filling of goaf.The shallow coal seam rapid filling mining method provided by the application has the advantage of rapid filling effect.

Description

Technical Field

[0001] This invention relates to the field of underground support technology, and in particular to a method for rapid backfilling mining of shallow coal seams. Background Technology

[0002] Shallow coal seams, with a burial depth not exceeding 150m, only have caving zones and fracture zones at the working face, lacking a slow subsidence zone. Because the working face lacks this "three-zone" structure, traditional surface grouting for overburden filling is not feasible. Furthermore, paste filling at the working face is costly and inefficient, failing to meet the need for efficient and rapid filling. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] The filling effect of shallow coal seams is poor.

[0005] The present invention aims to at least partially solve one of the technical problems in the related art.

[0006] Therefore, embodiments of the present invention propose a rapid backfilling mining method for shallow coal seams, comprising the following steps: arranging special chutes in the existing equipment sequence of the working face; the special chutes, in conjunction with hydraulic supports on the working face, construct at least two working channels connecting the working face's working space with the goaf behind it; setting up backfill wall construction areas between two adjacent working channels along the working face's direction; injecting backfill paste into the backfill wall construction areas within the goaf through the working channels, forming multiple backfill walls arranged discontinuously along the working face's direction within the goaf; connecting unfilled areas between adjacent backfill walls to form continuous backfill spaces; the interval between adjacent backfill walls being a preset distance; setting grouting holes on the ground in the unfilled areas; injecting backfill slurry into the backfill spaces; the backfill slurry flowing within the backfill spaces to complete the overall backfilling of the goaf.

[0007] The present invention has the advantages of rapid filling effect and technical benefits. This application combines the advantages of paste filling and overburden filling. First, paste filling technology is used to construct discontinuous filling walls in the goaf of the working face to prevent roof collapse. The discontinuous filling walls are interconnected and fillable spaces, creating an overburden filling environment. Grouting holes are set in the goaf to inject grout at a certain pressure into the areas of the goaf without filling walls, so as to achieve a rapid and efficient filling effect.

[0008] In some embodiments, the width of the special chute is half the length of the scraper conveyor or half the center distance of the hydraulic support. Multiple sets of special chutes and corresponding hydraulic supports are arranged at intervals along the working face to form multiple working channels. At the end of the working face, the end support is pushed by the lug to make the end support cooperate with the transition support to form an end working channel connecting the working face and the goaf. The special chute, the hydraulic support and the end support cooperate to set up multiple filling wall areas on the working face.

[0009] In some embodiments, the working face is intermittently filled, constructing multiple discontinuous filling walls in the goaf, wherein the span between adjacent filling walls is less than or equal to... , σ The allowable tensile strength of the overlying rock strata. H For the working face burial depth, γ It represents the unit weight of the overlying rock strata.

[0010] In some embodiments, a roof protection device is installed above the goaf passage of the working face to protect the working face operations.

[0011] In some embodiments, the system further includes a filling end support, with side retaining walls provided on the left and right sides of the upper retaining wall of the filling end support. The side retaining walls block the gangue on the side closer to the non-filling area and protect the slurry on the side closer to the filling area.

[0012] In some embodiments, a telescopic beam is provided on the side retaining wall, and a retaining wall jack is provided on the side retaining wall to push the telescopic beam to contact the working face bottom plate.

[0013] In some embodiments, the system further includes a diagonal bracing jack disposed between the upper retaining wall and the side retaining wall near the filling side to support the side retaining wall.

[0014] In some embodiments, the width of the upper retaining wall of the filling end support is the sum of the width of the hydraulic support and the width of the special chute. The upper retaining wall can swing upward to contact the top plate of the working face. The lower retaining wall is located at the bottom of the filling end support. The upper retaining wall can swing downward to contact the lower retaining wall. The upper retaining wall of the filling end support contacts the upper and lower retaining walls of the adjacent filling end support.

[0015] In some embodiments, the location of the grouting hole is selected according to the inclination angle of the working face. When the inclination angle of the working face is greater than a preset range, the grouting hole is set at a high position in the goaf, and gravity guides the flow of grout. When the inclination angle of the working face is less than the preset range, the grouting hole is set in the middle of the goaf, and the filling pump guides the flow of grout.

[0016] In some embodiments, the retaining wall jacks and the inclined bracing jacks retract synchronously, driving the side retaining wall to retract and form a rear passage for personnel to enter and exit between the hydraulic support and the goaf.

[0017] This application offers the following advantages: A special chute, combined with hydraulic supports, constructs an operating channel. Discontinuous filling walls are formed by grouting in the goaf, connecting unfilled areas. Combining the advantages of paste filling and overburden filling, the filling walls prevent roof collapse and provide interconnected, fillable spaces. Ground grouting enables rapid, integrated filling of the goaf. The width of the special chute is limited, and end supports and transition supports are used to form end operating channels. Multiple filling wall zones are constructed along the working face and at the ends, achieving a multi-point layout of filling spaces. The span of the discontinuous filling walls is set to not exceed the limit determined by the allowable tensile strength, burial depth, and unit weight of the rock strata, controlling the span between walls and preventing the subsidence of the overburden roof of shallow coal seams. A roof protection device is installed above the goaf channel to eliminate the hidden danger of a bare roof and protect the working face. Side retaining walls are installed on both sides of the upper retaining wall to act as rock retainers in non-filling areas and to protect against grout in filling areas, preventing grout from entering the support structure. The telescopic beam, driven by the retaining wall jacks, contacts the working face floor, enhancing the bottom support and sealing of the side retaining wall, and serving a dual function of blocking rock and grout. The inclined bracing jacks provide support to resist the pressure of the filling grout, preventing displacement of the side retaining wall and grout leakage. The width of the upper retaining wall is the sum of the width of the hydraulic support and the width of the special chute, allowing it to swing upwards to contact the roof or downwards to contact the lower retaining wall, thus fully sealing the top space at the filling end and forming a continuous seal with the adjacent retaining wall, preventing filling grout from entering the hydraulic support. The location of the grouting holes is selected according to the working face inclination angle; holes are placed at higher elevations for larger inclination angles and in the middle for smaller inclination angles to optimize the grout flow path and ensure rapid filling. The synchronous retraction of the retaining wall jacks and the inclined bracing jacks drives the side retaining wall to retract, forming a channel between the hydraulic support and the goaf, ensuring sealing and facilitating maintenance access. Attached Figure Description

[0018] Figure 1 This is a schematic diagram showing the location of the special chute and hydraulic support at the working face of the shallow coal seam rapid backfilling mining method according to an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram showing the location of the filling wall in the goaf of the shallow coal seam rapid filling mining method according to an embodiment of the present invention.

[0020] Figure 3 This is a schematic diagram of the span between the goaf filling wall and the adjacent filling wall in the rapid filling mining method for shallow coal seams according to an embodiment of the present invention.

[0021] Figure 4This is a schematic diagram showing the distance between the goaf filling wall and the hydraulic support in another direction of the shallow coal seam rapid filling mining method according to an embodiment of the present invention.

[0022] Figure 5 This is a schematic diagram showing the location of grouting holes in the rapid backfilling mining method for shallow coal seams according to an embodiment of the present invention.

[0023] Figure 6 This is a schematic diagram of the upper retaining wall and side retaining wall of the hydraulic support in the shallow coal seam rapid backfilling mining method according to an embodiment of the present invention.

[0024] Figure 7 This is a schematic diagram showing the supported state of the side retaining wall of the hydraulic support in the rapid backfilling mining method for shallow coal seams according to an embodiment of the present invention.

[0025] Figure 8 This is a schematic diagram of the retracted side retaining wall of the hydraulic support in the shallow coal seam rapid backfilling mining method according to an embodiment of the present invention.

[0026] Figure 9 This is a schematic diagram of the arrangement of hydraulic supports and adjacent supports in the rapid backfilling mining method for shallow coal seams according to an embodiment of the present invention.

[0027] Figure 10 This is a schematic diagram of the hydraulic support in use for the rapid backfilling mining method for shallow coal seams according to an embodiment of the present invention.

[0028] Attached reference numerals: 1. Special chute; 2. Hydraulic support; 3. Filling wall; 4. Working passage; 5. Filling end supports; 6. Side retaining wall; 7. Telescopic beam; 8. Retaining wall jack; 9. Diagonal brace jack; 10. Upper retaining wall; 11. Lower retaining wall; 12. Grouting hole. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] An embodiment of the present invention proposes a method for rapid backfilling mining of shallow coal seams, comprising the following steps: Special chutes are arranged in the existing equipment sequence of the working face. The special chutes, together with the hydraulic supports on the working face, form at least two working channels connecting the working space of the working face with the goaf behind. The special chutes are located in the existing equipment sequence of the working face. The hydraulic supports are hydraulic supports with lateral roof protection devices. The hydraulic supports have bidirectional lateral protection functions. They can prevent filling slurry from entering the hydraulic supports in the filling area and can block gangue in the unfilled area.

[0031] A filling wall construction area is set up between two adjacent working channels along the working face. Filling paste is injected into the filling wall construction area in the goaf through the working channels, forming multiple filling walls arranged discontinuously along the working face in the goaf. Discontinuous filling can prevent the overlying roof of shallow coal seams from sinking and create conditions for surface grouting and filling in the goaf.

[0032] The unfilled areas between adjacent filling walls are interconnected to form a continuous filling space. The interval between adjacent filling walls is a preset distance. The interconnected space facilitates the flow of filling grout, laying the foundation for rapid grouting filling of the goaf. The maximum span of the unfilled area is L, where L is as follows: Figure 3 and Figure 4 As shown.

[0033] Grouting holes are set in the ground of the unfilled area, and filling grout is injected into the filling space. The filling grout flows and fills the entire goaf to complete the filling.

[0034] In some embodiments, the width of the special chute is half the length of the scraper conveyor or half the center distance of the hydraulic support. Multiple sets of special chutes and corresponding hydraulic supports are arranged at intervals along the working face to form multiple working channels. At the end of the working face, the end support is pushed by the end support to make the end support cooperate with the transition support to form an end working channel connecting the working face and the goaf. The special chute, hydraulic support and end support are used to set up multiple filling wall areas on the working face.

[0035] Specifically, the width of the special chute is half the length of the entire scraper conveyor or half the center distance of the hydraulic supports. The size of the special chute can be adapted to the existing scraper conveyor and hydraulic supports on the working face, without the need for large-scale modification of the main mining equipment, thus reducing equipment modification costs and operational adaptation difficulties. Multiple sets of special chutes and corresponding hydraulic supports with lateral roof protection devices are arranged at intervals on the working face. Together, they form multiple working channels connecting the working face working space with the goaf behind. Roof protection devices are installed along the top of the goaf channels to ensure there is no open roof area above the channels, protecting the safety of working face operations and providing stable and safe personnel and material passage conditions for the construction of the goaf filling wall. At the head position, the arrangement of the end supports and transition supports forms an end operation channel connecting the working face and the goaf, achieving full coverage of the operation channel throughout the working face and eliminating blind spots in the end area filling operation. Special chutes, hydraulic supports with lateral roof protection devices, and end supports work together to divide the working face into multiple independent filling wall construction areas along the direction. Each pair of adjacent operation channels corresponds to an independent filling wall area, defining the operation boundary for the construction of discontinuous filling walls in the goaf, ensuring uniform spacing between multiple filling walls, and forming a continuous space between unfilled areas of adjacent filling walls, laying the foundation for rapid grouting filling of the goaf surface.

[0036] In some embodiments, the working face is intermittently filled, and multiple discontinuous filling walls are constructed in the goaf, with the span between adjacent filling walls being less than or equal to... σ is the allowable tensile strength of the overlying rock, H is the working face burial depth, and γ is the unit weight of the overlying rock.

[0037] Specifically, the working face adopts an intermittent filling method, constructing multiple discontinuous filling walls in the goaf, with the span between adjacent filling walls being less than or equal to... Where σ is the allowable tensile strength of the overlying rock, H is the working face burial depth, and γ is the unit weight of the overlying rock. The span limit is set based on the mechanical properties of the overlying rock of the shallow coal seam, anchoring the critical bearing condition that prevents the roof from collapsing, providing a basis for the interval arrangement of the filling walls. Discontinuous filling can effectively prevent the overlying roof of the shallow coal seam from sinking, creating conditions for surface grouting filling in the goaf. The unfilled areas between the filling walls are interconnected, facilitating the flow of filling grout, laying the foundation for rapid surface grouting filling in the goaf. Under the premise of ensuring roof stability, this span reserves space for connecting filling in the goaf, reducing the material consumption and operation time of paste filling, achieving roof control safety and improving filling efficiency. It is suitable for shallow coal seams with a burial depth of no more than 150m, where the working face only has collapse zones and fracture zones, and no slow subsidence zones, solving the problems that traditional surface grouting overlying rock filling technology cannot be implemented in shallow coal seams and that conventional paste filling is costly and inefficient. The working channel, constructed in conjunction with a special chute on the working face and a hydraulic support with a lateral roof protection device, enables the uniform spacing of multiple filling walls, ensuring uniform stress on the overlying rock strata, avoiding the risk of collapse caused by concentrated subsidence of the local roof, and providing a stable spatial foundation for rapid grouting and filling of the goaf in the subsequent process.

[0038] In some embodiments, a roof protection device is installed above the goaf passage of the working face to protect the working face operations.

[0039] Specifically, a roof protection device is installed along the route above the goaf passage in the working face. The roof protection device is connected with the lateral roof protection device of the hydraulic support, so that there is no empty roof area above the goaf passage, protecting the safety of working face operations and eliminating the risk of roof collapse and gangue falling in the goaf passage operation in the environment of shallow buried coal seam fractured roof. It provides continuous safety protection for the entire section for the passage of workers, the transfer of filling materials and the construction of filling walls. The roof protection device, together with the special chute and the hydraulic support with lateral roof protection device, forms a complete working passage support, avoiding the interruption of work or safety accidents caused by the instability of the passage roof. It forms a synergistic protection with the retaining structure of the support at both ends of the filling, and comprehensively covers the roof and lateral protection needs of goaf operations.

[0040] In some embodiments, the system further includes a filling end support, with side retaining walls provided on the left and right sides of the upper retaining wall of the filling end support. The side retaining walls block the gangue on the side closer to the non-filling area and protect the slurry on the side closer to the filling area.

[0041] Specifically, the side retaining wall near the non-filling area acts as a retainer against rockfall, while the side near the filling area acts as a protector against grout, preventing the filling grout from entering the hydraulic support. The supports at both ends of the filling wall construction area are arranged in conjunction with the special chute and lateral roof support of the working face, providing lateral boundary support for the single-section filling wall construction. The side retaining wall meets the protection needs of two different working areas, simplifies the supporting structure for filling at the working face, reduces equipment modification costs and on-site work procedures, and prevents rockfall from the goaf from entering the filling area and the working face space, providing stable lateral protection for the filling operation. The protective grout, together with the retaining wall and the retaining wall structure of adjacent supports, forms a closed filling boundary, preventing grout leakage during the filling process, improving the sealing effect of the filling operation, and ensuring that the grouting operation of each section of the filling wall can proceed stably in a closed and safe environment.

[0042] In some embodiments, a telescopic beam is provided on the side retaining wall, and a retaining wall jack is provided on the side retaining wall to push the telescopic beam to contact the bottom plate of the working face.

[0043] Specifically, during the backfilling operation at the working face, the retaining wall jacks extend, driving the telescopic beams of the side retaining walls downwards to contact the working face floor. This simultaneously achieves both the blocking of rockfill on the non-backfilling side and the protection of grout on the backfilling side. Furthermore, it provides stable vertical support to the upper retaining wall, preventing it from swaying downwards and achieving a seal between the side retaining walls and the working face floor. This eliminates the risk of grout leakage from gaps in the floor and strengthens the seal. The telescopic beams are adaptable to uneven working face floor conditions, ensuring stable rockfill and grout blocking functions under different geological conditions without requiring additional floor sealing structures.

[0044] In some embodiments, the system also includes a bracing jack, which is arranged between the upper retaining wall and the side retaining wall near the filling side to support the side retaining wall.

[0045] Specifically, the inclined bracing jacks provide stable support to the side retaining walls. During filling operations, the inclined bracing jacks extend and apply a supporting force to the side retaining walls on the filling side, opposite to the lateral pressure of the filling slurry. This prevents the filling slurry from pushing the side retaining walls to shift or deform under pressure, thus avoiding slurry leakage at the working face. When workers need to enter the goaf area behind the working face, the inclined bracing jacks and the matching retaining wall jacks retract synchronously, causing the side retaining walls to retract smoothly, facilitating workers' access to the back of the working face. The inclined bracing jacks counteract the lateral impact load of the high-pressure filling slurry on the side retaining walls, improving the structural stability and sealing effect of the side retaining walls. The inclined bracing jacks, together with the telescopic beams and retaining wall jacks, form a synergistic force to strengthen the sealing capability of the filling operation boundary, taking into account both the safety protection of the filling operation and the passage of the goaf area, ensuring the operational efficiency of the construction of discontinuous filling walls in shallow coal seams.

[0046] In some embodiments, the width of the upper retaining wall of the filling end support is the sum of the width of the hydraulic support and the width of the special chute. The upper retaining wall can swing upward to contact the top plate of the working face. The lower retaining wall is located at the bottom of the filling end support. The upper retaining wall can swing downward to contact the lower retaining wall. The upper retaining wall of the filling end support contacts the upper and lower retaining walls of the adjacent filling end support.

[0047] Specifically, the width of the upper retaining wall of the filling end supports is the sum of the width of the normal hydraulic support and the width of the special chute. This width can cover the support blind zone corresponding to the special chute, achieving connection with the support range of the hydraulic support and special chute on the working face, eliminating support and sealing gaps in the filling operation area. The upper retaining wall can swing upward to contact the top plate of the working face. During the filling operation, the upper retaining wall swings upward to completely fit the top plate of the working face, preventing the top plate from sinking, strengthening the support capacity of the top plate at both ends of the filling operation section, and ensuring the stability of the top plate structure during the filling operation. The lower retaining wall is set at the bottom of the filling end supports. The upper retaining wall swings downward to contact the lower retaining wall. The upper retaining wall of the filling end supports fully contacts the upper and lower retaining walls of the adjacent filling end supports, forming a closed sealing boundary for the filling operation, preventing the filling slurry from entering the hydraulic support, avoiding problems such as slurry flow and leakage during the filling operation, and ensuring reliable sealing of the filling operation. The upper retaining wall can work in conjunction with the side retaining walls, diagonal bracing jacks, and retaining wall jacks to form a synergistic sealing protection, adapting to the construction needs of intermittent non-continuous filling walls in shallow coal seams and ensuring the forming quality of each section of the filling wall.

[0048] In some embodiments, the location of the grouting hole is selected according to the dip angle of the working face. When the dip angle of the working face is greater than a preset range, the grouting hole is set at a high position in the goaf, and gravity guides the flow of grout. When the dip angle of the working face is less than a preset range, the grouting hole is set in the middle of the goaf, and the filling pump guides the flow of grout.

[0049] Specifically, this method selects the location of grouting holes based on the dip angle of the working face. When the dip angle is greater than a preset range, grouting holes are set at higher elevations in the goaf, using gravity to guide the filling grout to flow towards lower elevations. When the dip angle is less than a preset range, grouting holes are set in the middle of the goaf, using a filling pump to guide the grout flow. The unfilled areas between the filling walls are interconnected, facilitating the flow of the filling grout and laying the foundation for rapid surface grouting filling of the goaf. Grout under a certain pressure is injected through the grouting holes into areas of the goaf without filling walls, allowing the filling grout to flow within the interconnected spaces of the goaf. This differentiated grouting hole arrangement method is adapted to the on-site conditions of different dip angle working faces to achieve the filling effect. It optimizes the slurry flow path by using gravity or pump pressure, eliminates filling blind spots, and improves the slurry diffusion effect and filling operation efficiency. For large dip angle working faces, gravity drives the slurry flow, reducing the energy consumption of the filling pump group and reducing equipment investment. For near-horizontal small dip angle working faces, the central hole arrangement combined with pump pressure ensures that the slurry diffuses evenly to both sides of the goaf, avoiding the problems of slurry accumulation or incomplete filling. It solves the problems of low efficiency, high cost and inability to adapt to different dip angle working faces in traditional shallow coal seam filling technology.

[0050] In some embodiments, the retaining wall jacks and the inclined bracing jacks retract synchronously, driving the side retaining wall to retract and form a rear passage for personnel to enter and exit between the hydraulic support and the goaf.

[0051] Specifically, the retaining wall jacks and the inclined bracing jacks can retract synchronously, driving the side retaining wall to retract smoothly, forming a rear passage for personnel to enter and exit between the hydraulic support and the goaf. When it is necessary to enter from behind the working face, the retaining wall jacks and the inclined bracing jacks retract, retracting the side retaining wall to facilitate workers' access to the rear of the working face. The synchronous retraction and the sealing protection state of the jacks extending to support the side retaining wall during the filling operation form a switchable strategy. The opening and closing of the working passage can be quickly completed without additional disassembly and assembly of the support and sealing structure. It takes into account the anti-slurry leakage sealing requirements during the filling operation and the personnel passage requirements during non-filling operations, simplifies the operation process, shortens the preparation time, and makes on-site operations flexible. Synchronous retraction ensures uniform stress distribution during the retraction of the side retaining wall, avoiding structural deformation and damage caused by unilateral jamming, extending equipment service life, adapting to the cyclical operation mode of rapid backfilling mining in shallow coal seams, and forming a fully connected working path from the working face to the goaf by using a special chute and hydraulic support lateral roof protection device, achieving full coverage of personnel access between the working face working space and the deep area of ​​the goaf, providing safe and convenient access conditions for operations such as goaf roof condition monitoring and backfilling quality control.

[0052] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0054] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0056] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for rapid backfilling mining of shallow coal seams, characterized in that, Includes the following steps: Special chutes are arranged in the existing equipment sequence of the working face. The special chutes, together with the hydraulic supports on the working face, form at least two working channels that connect the working face working space with the goaf behind it. A filling wall construction area is set up between two adjacent working channels along the working face direction. Filling paste is injected into the filling wall construction area in the goaf through the working channels to form multiple filling walls arranged discontinuously along the working face direction in the goaf. The unfilled areas between adjacent filling walls are interconnected to form a continuous filling space, and the interval between the filling walls and the adjacent filling walls is a preset distance; Grouting holes are set in the ground of the unfilled area, and filling grout is injected into the filling space. The filling grout flows and fills the entire goaf within the filling space.

2. The method for rapid backfilling mining of shallow coal seams according to claim 1, characterized in that, The width of the special chute is half the length of the scraper conveyor or half the center distance of the hydraulic support. Multiple sets of special chutes and corresponding hydraulic supports are arranged at intervals along the working face to form multiple working channels. At the end of the working face, the end support is pushed by the lug to make the end support cooperate with the transition support to form an end working channel connecting the working face and the goaf. The special chute, the hydraulic support and the end support cooperate to set up multiple filling wall areas on the working face.

3. The method for rapid backfilling mining of shallow coal seams according to claim 1, characterized in that, The working face is intermittently filled, constructing multiple discontinuous filling walls in the goaf, wherein the span between adjacent filling walls is less than or equal to... , σ The allowable tensile strength of the overlying rock strata. H For the working face burial depth, γ It represents the unit weight of the overlying rock strata.

4. The method for rapid backfilling mining of shallow coal seams according to claim 1, characterized in that, A roof protection device is installed above the goaf passage of the working face to protect the working face operations.

5. The method for rapid backfilling mining of shallow coal seams according to claim 1, characterized in that, It also includes supports at both ends of the filling, and side retaining walls are set on the left and right sides of the upper retaining wall of the supports at both ends of the filling. The side retaining walls block the gangue on the side closer to the non-filling area and protect the slurry on the side closer to the filling area.

6. The method for rapid backfilling mining of shallow coal seams according to claim 5, characterized in that, The side retaining wall is equipped with a telescopic beam, and the side retaining wall is equipped with a retaining wall jack to push the telescopic beam to contact the working face bottom plate.

7. The method for rapid backfilling mining of shallow coal seams according to claim 6, characterized in that, It also includes diagonal bracing jacks, which are arranged between the upper retaining wall and the side retaining wall near the filling side to support the side retaining wall.

8. The method for rapid backfilling mining of shallow coal seams according to claim 5, characterized in that, The width of the upper retaining wall of the filling end support is the sum of the width of the hydraulic support and the width of the special chute. The upper retaining wall can swing upward to contact the top plate of the working face. The lower retaining wall is set at the bottom of the filling end support. The upper retaining wall can swing downward to contact the lower retaining wall. The upper retaining wall of the filling end support contacts the upper and lower retaining walls of the adjacent filling end support.

9. The method for rapid backfilling mining of shallow coal seams according to claim 1, characterized in that, The location of the grouting hole is selected according to the dip angle of the working face. If the dip angle of the working face is greater than the preset range, the grouting hole is set at a high position in the goaf, and gravity guides the flow of grout. If the dip angle of the working face is less than the preset range, the grouting hole is set in the middle of the goaf, and the filling pump guides the flow of grout.

10. The method for rapid backfilling mining of shallow coal seams according to claim 7, characterized in that, The retaining wall jacks and the inclined bracing jacks retract synchronously, driving the side retaining wall to fold up and form a rear passage for personnel to enter and exit between the hydraulic support and the goaf.

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