A method for pre-splitting top coal at an end of a fully-mechanized caving face

Abstract

The present application relates to the technical field of fully mechanized caving face, especially to the technical field of fully mechanized caving face end top coal, in particular to a kind of fully mechanized caving face end top coal precracking method.The present application is to solve the problem that fully mechanized caving face end top coal cannot be recovered, therefore provides a kind of fully mechanized caving face end top coal precracking method, comprising the following steps:1) the directional cutting machine is placed in the roadway;2) using directional cutting machine to cut fully mechanized caving face end top coal;3) within the range of directional cutting machine cutting, drill holes at intervals, then adopt bubble mud hole sealing after leading out detonating cord and then detonating;4) using the support roadway of unit support, so that the roadway section is stably supported by unit support;5) while advancing the working face at a uniform speed, repeatedly execute the cutting of directional cutting machine, drilling blasting, support of unit support, until the top coal precracking of entire fully mechanized caving face is completed, and the method effectively improves the recovery rate of fully mechanized caving face end top coal.

Description

Technical Field

[0001] This invention relates to the field of fully mechanized longwall mining face technology, and particularly to the field of top coal technology at the end of a fully mechanized longwall mining face, specifically a method for pre-splitting the top coal at the end of a fully mechanized longwall mining face. Background Technology

[0002] Top coal caving is one of the mainstream coal mining techniques in my country, improving coal extraction efficiency compared to traditional methods. However, during mining, the cantilever beam structure and the constraint of roadway anchor cables and bolts at the end of the fully mechanized longwall face prevent the recovery of top coal, resulting in resource waste and reduced coal extraction rate. Currently, pre-splitting of the top coal at the end of the fully mechanized longwall face is an effective means to solve the above problems, including continuous and discontinuous top cutting. However, continuous top cutting can easily affect the anchoring system of the end roadway, while discontinuous top cutting can easily cause top coal caving difficulties and collapse. Summary of the Invention

[0003] In order to solve the problem of the inability to recover the top coal at the end of a fully mechanized longwall mining face, this invention provides a method for pre-splitting the top coal at the end of a fully mechanized longwall mining face.

[0004] This invention is achieved using the following technical solution:

[0005] A method for pre-splitting the top coal at the end of a fully mechanized longwall mining face includes the following steps: 1) placing a directional cutting machine in the roadway; 2) using the directional cutting machine to cut the top coal at the end of the fully mechanized longwall mining face; 3) drilling holes at certain intervals within the cutting range of the directional cutting machine, then sealing the holes with mud before leading out detonating cords and detonating them; 4) using unit supports to support the roadway, so that the roadway cross-section is stably supported by the unit supports; 5) while advancing the working face at a uniform speed, repeatedly performing cutting with the directional cutting machine, drilling and blasting, and support with unit supports until the pre-splitting of the top coal of the entire fully mechanized longwall mining face is completed.

[0006] The beneficial effects of this invention are as follows: This invention breaks with conventional thinking by combining continuous cutting with directional cutting machine and discontinuous blasting to achieve pre-splitting of the top coal at the end of the fully mechanized longwall mining face, thereby improving the recovery rate of the top coal at the end of the fully mechanized longwall mining face. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the tunnel layout of the present invention;

[0008] Figure 2 This is a schematic diagram of section II;

[0009] Figure 3 This is a schematic diagram of section II-II.

[0010] In the diagram: 1—directional cutting machine, 2—roadway, 3—cutting tool, 4—roadway side, 5—roadway centerline, 6—drill hole, 7—mud soaking, 8—detonating cord, 9—unit support, 10—working face, 11—goaf. Detailed Implementation

[0011] A method for pre-splitting the top coal at the end of a fully mechanized longwall mining face includes the following steps: 1) Place the directional cutting machine 1 in the roadway 2, and adjust the cutter of the directional cutting machine 1 so that the distance between it and the roadway side 4 is B. When the width D of the roadway 2 is 3-4m, B is (0.08-0.10)D; when the width D of the roadway 2 is 4-5m, B is (0.07-0.08)D; when the width D of the roadway 2 is 5-6m, B is (0.06-0.07)D; 2) Use the directional cutting machine 1 to cut the top coal at the end of the fully mechanized longwall mining face. The specific steps are as follows: a. Using u Chain speed of 1 oh a) The rotational speed of 1 will rotate the cutting tool 3 along the direction of the roadway centerline 5 and cut to another horizontal position; b) The directional cutting machine 1 will be moved a distance S1 along the roadway centerline 5 towards the working face 10, where 0 < the vertical stress of the surrounding rock where the roadway 2 is located ≤ 8MPa. S 1 is 8~10m; when 8 < the vertical stress of the surrounding rock at the location of tunnel 2 is ≤25MPa, S 1 is 6~8m; when the vertical stress of the surrounding rock in roadway 2 is >25MPa, S 1 is 4~6m; c, with u Chain speed of 2 oh The rotational speed of step 2 will rotate the cutting tool 3 along the direction of the tunnel centerline 5 and cut to another horizontal position; step d, repeat steps b and c until the cumulative cutting distance of the directional cutting machine 1 along the tunnel centerline 5 towards the working face 10 exceeds L1, where 0 < the horizontal stress of the surrounding rock where tunnel 2 is located ≤ 10 MPa, L Set 1 to (6.0~7.5) S 1. When 10 < the horizontal stress of the surrounding rock at the location of tunnel 2 is ≤30MPa, L 1 is set to (3.0~5.5) S 1. When the horizontal stress of the surrounding rock in roadway 2 is >30MPa, L 1 is set to (2.0~3.0) S 1; among the steps a , c The chain speed described in u 1. u 2. The rotational speeds ω1 and ω2 are related to the uniaxial compressive strength of the immediate roof of roadway 2: when 0 < uniaxial compressive strength of the immediate roof of roadway 2 ≤ 18 MPa, υ1 is 1.2 m / s and υ2 is 1.5 m / s. u 1, oh1 is 45° / h oh 2 is 1.5 oh 1; When 18 < the uniaxial compressive strength of the direct roof of the roadway 2 ≤ 50 MPa, u 1 represents 1.0 m / s. u 2 is 1.3 u 1， oh 1 is 30° / h oh 2 is 1.2 oh 1; When the uniaxial compressive strength of the direct roof of roadway 2 is >50MPa, u 1 is 0.5 m / s u 2 is 1.2 u 1, oh 1 is 15° / h, oh 2 is 1.1 oh 1;3) Within the cutting range of the directional cutting machine 1, drill holes 6 at certain intervals, then seal the holes with mud 7 before leading out the detonating cord 8 and detonating. The drilling diameter of the holes 6 is D1, the depth is D2, and the hole spacing is M1. The depth of the mud 7 is H and is two-thirds of the length of the filling explosive, until the cumulative distance of the drilled holes 6 along the center line 5 of the roadway towards the working face 10 exceeds [a certain value]. L 2. When 0 MPa < uniaxial compressive strength of the immediate roof of roadway 2 ≤ 35 MPa, L 2 is (0.35~0.40) L 1; When 35MPa < uniaxial compressive strength of the immediate roof of roadway 2 ≤ 40MPa, L 2 represents (0.30~0.35) L 1; When the uniaxial compressive strength of the direct roof of roadway 2 is >40MPa, L 2 represents (0.25~0.30) L 1; where the borehole diameter is... D 1. Depth D 2. Hole spacing M1. Related to the Protodyakonov coefficient of the immediate roof and the depth of the stem cut, H: When 0 < Protodyakonov coefficient of the immediate roof ≤ 5, D1 is 0.025~0.030m, D2 is (1.0~1.2)H, and M1 is 1.25~1.35m; when 5 < Protodyakonov coefficient of the immediate roof ≤ 9, D1 is 0.030~0.035m, D2 is (1.2~1.35)H, and M1 is 1.35~1.45m; when the immediate roof... When the top Protodyakonov coefficient is >9, D1 is 0.035~0.040m, D2 is (1.35~1.40)H, and M1 is 1.45~1.50m; 4) Use unit supports 9 to support roadway 2, so that the cross-section of roadway 2 is stably supported by unit supports 9. Among them, the row spacing M2 and the support resistance P of unit supports 9 are related to the burial depth of roadway 2: when the burial depth of roadway 2 is >600m, P=2500KN, M 2 is 1.2~1.8m; when the burial depth of roadway 2 is ≤600m, P=1800KN, M2 is 1.8~2.2m; 5) while advancing the working face 10 at a uniform speed, repeatedly perform cutting by directional cutting machine 1, blasting by drilling 6, and support by unit support 9 until the top coal pre-splitting of the entire fully mechanized longwall working face 10 is completed. Among them, when the cumulative distance of unit support 9 in goaf 11 exceeds L3, the unit support 9 in goaf 11 is withdrawn. Among them, when 0MPa < uniaxial compressive strength of the direct roof of roadway 2 ≤25MPa, L2 is (0.30~0.35)L1; when 25MPa < uniaxial compressive strength of the direct roof of roadway 2 ≤35MPa, L2 is (0.35~0.40)L1; when the uniaxial compressive strength of the direct roof of roadway 2 >35MPa, L2 is (0.40~0.45)L1.

[0012] This embodiment takes a fully mechanized longwall face 10 of Jineng Holding Group as an example. The width of the roadway 2 is 5.5m, the uniaxial compressive strength of the direct roof of roadway 2 is 70MPa, the vertical stress of the surrounding rock of roadway 2 is 12MPa, the horizontal stress is 25MPa, the solidity coefficient of the direct roof of roadway 2 is 7, the length of the filling explosive is 1.6m, and the burial depth of roadway 2 is 750m. The pre-splitting method of the top coal at the end of the fully mechanized longwall face includes the following steps: 1) Place the directional cutting machine 1 in the roadway 2 and adjust the blade of the directional cutting machine 1 so that the distance between it and the roadway side 4 is 0.33m; 2) Use the directional cutting machine 1 to cut the top coal at the end of the fully mechanized longwall face. The specific steps are as follows: a. Using u 1 represents a chain speed of 0.5 m / s. oh 1. Rotate the cutting tool 3 at a rotation speed of 15° / h along the direction of the roadway centerline 5 and cut to another horizontal position; b. Move the directional cutting machine 1 7.5m along the roadway centerline 5 towards the working face 10; when the vertical stress of the surrounding rock in the roadway 2 is >25MPa, S 1 is 4~6m; c, with u 2 represents a chain speed of 0.6 m / s. oh 2. Rotate the cutting tool 3 at a rotation speed of 16.5° / h and cut to another horizontal position; d. Repeat steps b and c until the directional cutting machine 1 has cut a cumulative distance of more than 30.0m along the roadway centerline 5 towards the working face 10; 3) Drill holes 6 at certain intervals within the cutting range of the directional cutting machine 1, then seal the holes with mud 7 and lead out the detonating cord 8 for detonation. The drilling diameter of the holes 6 is 0.03m, the depth is 1.42m, the hole spacing is 1.40m, and the mud 7 depth is 1.06m, until the cumulative drilling distance of the holes 6 along the roadway centerline 5 towards the working face 10 exceeds 10m; 4) Use unit supports 9 to support the roadway 2, so that the cross-section of the roadway 2 is stably supported by the unit supports 9, wherein the unit supports The spacing of the frame 9 is 1.55m and the support resistance is 2500KN; 5) While advancing the working face 10 at a uniform speed, the cutting of the directional cutting machine 1, the blasting of the drilling 6, and the support of the unit support 9 are repeatedly performed until the top coal pre-splitting of the entire fully mechanized longwall working face 10 is completed. When the cumulative distance of the unit support 9 in the goaf 11 exceeds L3, the unit support 9 in the goaf 11 is withdrawn. When the uniaxial compressive strength of the direct roof of the roadway 2 is >35MPa, L3 is 12m.

Claims

1. A method for pre-splitting of top coal at the end of a fully-mechanized coal mining face, characterized in that, The method comprises the following steps: 1) placing a directional cutting machine (1) in a roadway (2); 2) cutting the top coal at the end of the fully-mechanized caving face by using the directional cutting machine (1), and the specific steps of the directional cutting machine (1) during cutting are as follows: a, rotating and cutting the cutting tool (3) to another horizontal position along the direction of the roadway center line (5) at the chain speed of the directional cutting machine (1) and the rotating speed of the directional cutting machine (1); b, moving the directional cutting machine (1) along the roadway center line (5) to the working face (10) by a distance S1, wherein when 0 < the vertical stress of the surrounding rock where the roadway (2) is located ≤ 8 MPa, υ 1, the distance S1 is 8-10 m. ω 1, the distance S1 is 8-10 m. S 1, the distance S1 is 8-10 m. When 8 < the vertical stress of the surrounding rock where the roadway (2) is located ≤ 25 MPa, S 1 is 6-8 m; when the vertical stress of the surrounding rock where the roadway (2) is located > 25 MPa, S 1 is 4-6 m; c, the chain speed of υ 2, ω 2 rotates the cutting tool (3) in the direction of the roadway center line (5) and cuts to another horizontal position; d, repeat steps b, c, until the cumulative cutting distance of the directional cutting machine (1) along the roadway center line (5) in the direction of the working face (10) exceeds L1, wherein when 0 < the horizontal stress of the surrounding rock where the roadway (2) is located ≤ 10 MPa, L 1 is set to (6.0-7.5) S 1, when 10 < the horizontal stress of the surrounding rock where the roadway (2) is located ≤ 30 MPa, L 1 is set to (3.0-5.5) S 1; when the horizontal stress of the surrounding rock where the roadway (2) is located > 30 MPa, L 1 is set to (2.0-3.0) S 1; wherein the chain speed a 1, c 2 in steps υ 、 υ 2, the rotation speed ω1, ω2 is associated with the uniaxial compressive strength of the immediate roof of the roadway (2): when 0 < the uniaxial compressive strength of the immediate roof of the roadway (2) ≤ 18 MPa, υ1 is 1.2 m / s, υ2 is 1.5 υ 1, ω 1 is 45° / h, ω 2 is 1.5 ω 1; when 18 < the uniaxial compressive strength of the immediate roof of the roadway (2) ≤ 50 MPa, υ 1 is 1.0 m / s, υ 2 is 1.3 υ 1， ω 1 is 30° / h, ω 2 is 1.2 ω 1; when the uniaxial compressive strength of the immediate roof of the roadway (2) > 50 MPa, υ 1 is 0.5 m / s, υ 2 is 1.2 υ 1, ω 1 is 15° / h, ω 2 is 1.1 ω 1;3) in the range of cutting of the directional cutting machine (1), drill holes (6) at intervals, the drilling diameter of the holes (6) is D1, the depth is D2, the hole spacing is M1, the depth of the bubble mud (7) is H, until the cumulative distance of the holes (6) along the roadway center line (5) to the working face (10) direction exceeds L 2, wherein, when 0 < immediate roof Protodyakonov coefficient ≤ 5, D1 is 0.025~0.030m, D2 is (1.0~1.2)H, M1 is 1.25~1.35m; when 5 < immediate roof Protodyakonov coefficient ≤ 9, D1 is 0.030~0.035m, D2 is (1.2~1.35)H, M1 is 1.35~1.45m; when immediate roof Protodyakonov coefficient > 9, D1 is 0.035~0.040m, D2 is (1.35~1.40)H, M1 is 1.45~1.50m; when 0MPa < uniaxial compressive strength of the immediate roof of the roadway (2) ≤ 35MPa, L 2 is (0.35~0.40) L 1; when 35MPa < uniaxial compressive strength of the immediate roof of the roadway (2) ≤ 40MPa, L 2 is (0.30~0.35) L 1; when uniaxial compressive strength of the immediate roof of the roadway (2) > 40MPa, L 2 is (0.25~0.30) L 1, then the bubble mud (7) is used to seal the hole, and the detonating cord (8) is led out and detonated; 4) the roadway (2) is supported by using the unit support (9), so that the section of the roadway (2) is stably supported by the unit support (9); 5) the working face (10) is advanced at a uniform speed, and the cutting of the directional cutting machine (1), the blasting of the holes (6) and the support of the unit support (9) are repeatedly executed at the same time, until the top coal pre-cracking of the fully mechanized caving face is completed.

2. The method according to claim 1, characterized in that, In step 1, the cutter of the directional cutting machine (1) is adjusted to have a distance B from the roadway side (4), when the roadway (2) has a width D of 3-4 m, B is (0.08-0.10)D; when the roadway (2) has a width D of 4-5 m, B is (0.07-0.08)D; when the roadway (2) has a width D of 5-6 m, B is (0.06-0.07)D.

3. The method according to claim 2, characterized in that, The depth H of the bubble mud (7) is two-thirds of the length of the filling explosive.

4. The method according to claim 3, characterized in that, In step 4, the row spacing M2 and the support resistance P of the unit support (9) are associated with the buried depth of the roadway (2): when the buried depth of the roadway (2) is >600 m, P=2500 KN, and M2 is 1.2-1.8 m; when the buried depth of the roadway (2) is ≤600 m, P=1800 KN, and M2 is 1.8-2.2 m.

5. The method according to claim 4, characterized in that, When the cumulative distance of the unit support (9) in the goaf (11) exceeds L3, the unit support (9) in the goaf (11) is withdrawn, wherein when 0 MPa When the cumulative distance of the unit support (9) in the goaf (11) exceeds L3, the unit support (9) in the goaf (11) is withdrawn, wherein when 0 MPa

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