A method for underground mining, dressing and filling integrated coal gangue filling and replacement of section coal pillars

Abstract

The present invention provides a method for replacing a segmented coal pillar with gangue filling in an integrated underground mining, sorting and filling process, which relates to the field of coal recovery technology and includes the following steps: respectively opening a transport chute and a return air chute on the left and right sides of the segmented coal pillar, the transport chute and the return air chute being connected by a chute connecting lane, mining and filling the even-numbered strips in sequence, and then mining and filling the odd-numbered strips. The segmented coal pillar adopts an odd-even segmented mining method, and after mining, a filling slurry is used to prepare a chamber to sort coarse coal and gangue, and the gangue is made into gangue filling slurry and filled into the goaf of the segmented coal pillar, thus realizing an integrated operation of mining, sorting and filling. The method is applicable to underground mining areas with multiple working faces, efficiently recovering coal pillar resources, and has good application prospects and a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of coal recovery, in particular to a method for underground mining, dressing and filling integrated coal gangue filling and replacement of section coal pillars. Background Art

[0002] During the coal mining process, the retention of section coal pillars causes a large amount of coal resources to remain underground, resulting in a waste of coal resources.

[0003] Gangue filling technology is a method of filling goaf with gangue during the coal mining process. The gangue is sorted and prepared as filling material on the surface before being transported underground for filling.

[0004] In view of this, how to provide a method for using coal gangue to fill and replace section coal pillars to avoid waste of coal resources is an urgent problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for underground mining, dressing and filling integrated coal gangue filling and replacement of section coal pillars, so as to solve the problems existing in the prior art.

[0006] To achieve the above-mentioned object, the present invention provides a method for underground mining, dressing and filling integrated coal gangue filling and replacement of coal pillars in a section, comprising the following steps:

[0007] S1: A section coal pillar is formed between adjacent working faces. A transport chute and a return air chute are respectively opened on the left and right sides of the section coal pillar. The transport chute and the return air chute are connected by a chute connecting lane. A movable belt conveyor is arranged in the chute connecting lane, and a belt conveyor is arranged in the transport chute.

[0008] S2: Divide the coal pillar into multiple strips evenly along the length of the transport chute, and number the strips in sequence as A1, A2, A3 to An;

[0009] S3: Mining is carried out on the even-numbered strips in the order of numbering. The mining direction is from the return air chute to the transport chute. The mined coal is discharged via the movable belt conveyor and the belt conveyor.

[0010] S4: Fill the strips with even numbers in sequence, using coal gangue filling slurry, which is transported from the return air chute to the strips;

[0011] S5: Mining the odd-numbered strips in order, with the mining direction from the return air chute to the transport chute. The mined coal is discharged via the movable belt conveyor and the belt conveyor;

[0012] S6: Fill the odd-numbered strips in sequence using gangue filling slurry, which is transported from the return air chute to the strips.

[0013] Furthermore, the connecting tunnel of the drift is located 10-15m below the supporting pressure zone of the working face.

[0014] Furthermore, in step S1, the transport chute is formed by the transport uphill excavation working face, and the return air chute is formed by the return air uphill excavation working face.

[0015] Furthermore, in steps S3-S6, when the strip numbered An is mined, the strip numbered An-2 is used as the connecting tunnel of the drift and a movable belt conveyor is arranged to fill the strip numbered An-4 or the original connecting tunnel of the drift.

[0016] Furthermore, the thickness of the strip is 5m. In steps S3-S6, the working face and the strip are mined simultaneously. The strip mining speed and filling speed are both 5m / d, and the working face mining speed is 4m / d.

[0017] Furthermore, in steps S3 and S5, the strips after mining form goafs, anchor rods and anchor cables are driven into the roof of the goaf, and anchor rods are driven into both sides of the goaf.

[0018] Furthermore, in steps S3 and S5, the coal is output to the filling slurry preparation chamber via a movable belt conveyor and a belt conveyor, and the coal is sorted into coarse carbon and gangue. The coarse coal is transported up the mountain and output, and the gangue is crushed to form gangue filling slurry, and the gangue filling slurry is transported to the strip through the return air up the mountain and the return air chute.

[0019] Furthermore, steps S1-S6 are repeated to mine all working faces and mine and fill all sections of coal pillars.

[0020] The present invention discloses the following technical effects:

[0021] The present application establishes a complete method for replacing segmented coal pillars with gangue filling. The segmented coal pillars adopt an odd-even segmented mining method. After mining, the filling slurry is used to prepare the chamber to sort coarse coal and gangue. The gangue is made into gangue filling slurry and filled into the goaf of the segmented coal pillars, realizing the integrated operation of mining, sorting and filling. It can be applied to underground mining areas with multiple working faces, efficiently recover coal pillar resources, and has good application prospects and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 This is a schematic diagram of the initial stage of coal pillar mining at the first working face and the first section;

[0024] Figure 2 This is a schematic diagram of the mining of the first working face and the mining and filling of the coal pillar in the first section;

[0025] Figure 3 This is a schematic diagram of the initial stage of coal pillar mining at the second working face and the second area;

[0026] Figure 4 This is a schematic diagram of the mining of the second working face and the mining and filling of the coal pillar in the second section;

[0027] Figure 5 Schematic diagram of strip division;

[0028] Figure 6 Schematic diagram of goaf formed by strip mining;

[0029] Among them, 1. Transport up the mountain; 2. Track up the mountain; 3. Return air up the mountain; 4. First transport chute; 5. First return air chute; 6. Chute connecting tunnel; 7. First section coal pillar; 8. First working face; 9. Second working face; 10. Second transport chute; 11. Second return air chute; 12. Coal gangue connecting tunnel; 13. Filling slurry preparation chamber; 14. Coal transport connecting tunnel; 15. Coal connecting tunnel; 16. Coal gangue filling retaining wall; 17. Filling body; 18. Second section coal pillar. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figures 1-6As shown, an embodiment of the present invention provides a method for replacing a segmented coal pillar with gangue filling by integrating underground mining, dressing and filling, which is applied to a coal mine. The parameters of the mine are as follows: the production capacity is 3 million tons / year, the length of the working face is L, the width of the segmented coal pillar is W, and the average thickness of the coal seam is H, which is 5 meters; the working face advances 5 times a day, each cut is 0.8 meters, the advancement speed x is 4 meters / day, the coal seam gangue content μ is 10%, and the coal density ρ is 1.4 tons / m 3 , the density of gangue ρ' is 1.8t / m 3 .

[0033] The following steps are involved:

[0034] S1: This embodiment illustrates three working faces in the initial stage of mining. The left side is the first working face 8, the middle is the second working face 9, and the right side is the third working face. Between the first and second working faces 8 and 9 is the first segmented coal pillar 7, and between the second and third working faces is the second segmented coal pillar 18. A transport chute and a return air chute are respectively established on the left and right sides of the segmented coal pillar. The transport chute extends from the transport uphill excavation face 1 to the mining boundary, and the return air chute extends from the return air uphill excavation face 3 to a point 10-15 meters below the bearing pressure zone of the working face.

[0035] It should be noted that in coal mining, transport uphill 1, track uphill 2 and return air uphill 3 are three inclined tunnels with different functions, each of which has different tasks:

[0036] Transport up the mountain 1

[0037] Uphill transport 1 refers to an inclined roadway used for transporting coal. It is typically equipped with a belt conveyor, hence the name "belt uphill transport." Its primary function is to transport coal from the mining area to the surface or other processing locations. Uphill transport 1 is arranged uphill, meaning it is excavated upward from the main transport roadway along the coal seam or rock stratum.

[0038] Tracks up the mountain 2

[0039] Track Uphill 2 is an inclined tunnel used to transport materials, equipment, and waste rock. It is equipped with tracks and primarily uses mine cars or electric locomotives for transportation. It not only transports materials but also serves as an auxiliary transport vehicle for transporting personnel and supplies. Track Uphill 2 also slopes upward from the transport level.

[0040] Back to the mountain 3

[0041] The return air uphill tunnel 3 is an inclined tunnel used for mine ventilation. Its primary function is to guide polluted air (air containing harmful substances such as gas and coal dust) within the mining area into the mine's main return air system. This ensures fresh air circulation within the mining area and provides a safe working environment for miners. The return air uphill tunnel 3 is also excavated upward from the main transport tunnel along the coal seam or rock stratum.

[0042] These three types of uphill tunnels are very important in the production system of coal mines. Together they ensure the efficient production and safe operation of coal mines.

[0043] Specifically, the first transport chute 4 and the first return air chute 5 are located on the left and right sides of the first working face 8, while the second transport chute 10 and the second return air chute 11 are located on the left and right sides of the second working face 9. The first transport chute 4 and the first return air chute 5 are connected by a chute connecting tunnel 6, which is located 10-15 meters below the supporting pressure zone of the working face. A movable belt conveyor is arranged in the chute connecting tunnel 6, while a belt conveyor is arranged in the first transport chute 4.

[0044] S2: Divide the coal pillar into multiple strips evenly along the length of the first transport chute 4, and number the strips A1, A2, A3 to A10 in sequence;

[0045] S3: Mining the first working face 8 and the first section coal pillar 7 simultaneously. Mining the even-numbered strips sequentially from the first return air chute 5 to the first transport chute 4, with the mining direction generally perpendicular to the length of the first transport chute 4. The mined coal is transferred by a loader to the chute connecting tunnel 6 and then to the movable conveyor, where it is discharged via the movable belt conveyor and the belt conveyor.

[0046] S4: Fill the even-numbered strips in order of numbering, using gangue filling slurry, which is transported from the return air chute to the strips. Not all strips are mined before filling. When the strip numbered A2 is mined, the chute connecting tunnel 6 is filled with gangue filling slurry to form a gangue filling retaining wall 16. At the same time, the strip numbered A4 is mined. At this time, the goaf of the strip numbered A2 is used as the new goaf connecting tunnel 6. Similarly, in the subsequent mining and filling process, when the strip numbered An is mined, the strip numbered An-2 is used as the new goaf connecting tunnel 6 and a movable belt conveyor is arranged to fill the strip numbered An-4. In steps S3 and S5, the mined strips form goafs, and anchor bolts and anchor cables are installed on the roof of the goaf, and anchor bolts are installed on both sides of the goaf.

[0047] S5: Mining the odd-numbered strips in order, with the mining direction from the return air chute to the transport chute. The mined coal is discharged via the movable belt conveyor and the belt conveyor;

[0048] S6: Fill the odd-numbered strips sequentially using gangue filling slurry, delivered to the strips via the return air chute. Each strip has a width y of 5m. The mining and filling rate y for the first section of coal pillar 7 is 5m / day. After compaction, the gangue filling retaining wall 16 forms a filling body 17, with a crushing expansion coefficient β of 0.05.

[0049] In steps S3 and S5, the coal mined from the first working face 8 and the first section coal pillar 7 is transported to the filling slurry preparation chamber 13 via the transport chute, the transport uphill 1 and the coal transport connecting tunnel 14. The filling slurry preparation chamber 13 sorts the coal into coarse carbon and gangue, and the coarse coal is transferred back to the transport uphill 1 for output through the coal connecting tunnel 15. The gangue is crushed to make gangue filling slurry, and the gangue filling slurry is transported to the strip through the gangue connecting tunnel 12, the return air uphill 3 and the return air chute by a grouting pump.

[0050] Numerical simulation is used to obtain the stress increase area during the mining of the second working face 9. When the coal gangue filling retaining wall 16 is fully compacted to form a filling body 17, and the filling body 17 closest to the transportation uphill 1 is 10-15m away from the stress increase area of ​​the second working face 9, the mining and filling work of the second working face 9 and the second section coal pillar 18 is started.

[0051] Repeat the above steps until all working faces and sections of coal pillars are mined and filled. When the distance between the working face and the filling slurry preparation chamber 13 reaches 1000-1200m, a new filling slurry preparation chamber 13 can be established.

[0052] In the above steps, in order to ensure that the filling slurry preparation chamber 13 can prepare sufficient coal gangue filling slurry, various working parameters during mining should be limited. The following conditions must be met:

[0053] LHxμρ'+WHyμρ'>WHyρ'(1 / (1+β))

[0054] It can be obtained that L>13W; assuming that the width of the section coal pillar is designed to be 20m, the working face length is at least 260m; assuming that the actual production time of the mine is 330 days a year, 9,100 tons of coal must be produced every day. It can be calculated that the required working face length is 295m, which can meet the filling requirements.

[0055] According to the production capacity of the filling slurry preparation chamber 13, during the filling of a strip, the filling slurry preparation chamber 13 must be able to sort out the amount of gangue required for the next filling strip, that is, WHyρ' (1 / (1+β)), and the production capacity of the filling slurry preparation chamber 13 is at least 1029t / d.

[0056] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0057] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for underground mining, dressing and filling integrated coal gangue filling and replacement of section coal pillars, characterized in that: The following steps are involved: S1: A section coal pillar is formed between adjacent working faces. A transport chute and a return air chute are respectively opened on the left and right sides of the section coal pillar. The transport chute and the return air chute are connected by a chute connecting lane (6). A movable belt conveyor is arranged in the chute connecting lane (6), and a belt conveyor is arranged in the transport chute; S2: Divide the coal pillar into multiple strips evenly along the length of the transport chute, and number the strips in sequence as A1, A2, A3 to An; S3: Mining is carried out on the even-numbered strips in the order of numbering. The mining direction is from the return air chute to the transport chute. The mined coal is discharged via the movable belt conveyor and the belt conveyor. S4: Fill the strips with even numbers in sequence, using coal gangue filling slurry, which is transported from the return air chute to the strips; S5: Mining the odd-numbered strips in order, with the mining direction from the return air chute to the transport chute. The mined coal is discharged via the movable belt conveyor and the belt conveyor; S6: Fill the odd-numbered strips in order of numbering, using coal gangue filling slurry, which is transported from the return air chute to the strips; The connecting tunnel (6) is located 10-15m below the supporting pressure zone of the working face; In step S1, the transport chute is formed by the transport uphill (1) excavation working face, and the return air chute is formed by the return air uphill (3) excavation working face; In steps S3-S6, when the strip numbered An is mined, the strip numbered An-2 is used as the connecting tunnel (6) and a movable belt conveyor is arranged to fill the strip numbered An-4 or the original connecting tunnel (6); The thickness of the strip is 5m. In steps S3-S6, the working face and the strip are mined simultaneously. The strip mining speed and filling speed are both 5m / d, and the working face mining speed is 4m / d. In steps S3 and S5, the coal is output to the filling slurry preparation chamber (13) via a movable belt conveyor and a belt conveyor, and the coal is sorted into coarse coal and gangue. The coarse coal is output by transporting uphill (1), and the gangue is crushed to form gangue filling slurry. The gangue filling slurry is transported to the strip through the return air uphill (3) and the return air chute; In steps S3 and S5, the strip after mining forms a goaf, anchor rods and anchor cables are driven into the roof of the goaf, and anchor rods are driven into both sides of the goaf; Repeat steps S1-S6 to mine all working faces and mine and fill all sections of coal pillars.

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