Arrangement and mining method of negative-carbon different-plane filling system

Abstract

The invention discloses a negative-carbon different-face filling system arrangement and mining method which comprises the following specific steps: firstly, during working face filling mining operation, retaining a mining roadway on one side of a filling section by utilizing a gob-side entry retaining technology, and reinforcing by adopting a roadway-side support body to serve as a CO2 filling roadway of the working face and a mining roadway on one side of an adjacent filling working face; then, a roadway is stoped from the adjacent working face, drill holes are formed in the mined-out area where the closed space is formed, and CO2 filling pipelines are arranged in the mining roadway and the drill holes; and finally, CO2 is injected into the goaf gangue high-pore filling body by a CO2 injection pump through a CO2 injection and filling pipeline, after filling mining of adjacent working faces is completed, CO2 injection is stopped, and a coal mining-filling-injection and filling cycle is completed. The system is simple in arrangement and flexible in operation, the dual purposes of solid waste disposal and CO2 storage are achieved, and green mining of coal resources is achieved.

Description

Technical Field

[0001] The present invention belongs to the field of backfill mining, gob-side tunnelling technology and carbon neutrality, and specifically relates to a negative carbon off-surface backfill system layout and mining method. Background Art

[0002] Coal resources are mined in large quantities from underground rock formations to form goafs, which cause the overlying rock formations to become unstable and trigger geological and environmental disasters. Backfill mining technology has significant technical advantages in surface subsidence control, ecological environmental protection, and mine solid waste disposal and utilization. It can solve the problems of surface subsidence, groundwater loss, gas emissions, and land occupation damage from the source of coal resource mining. However, the existing backfilling technology also has some shortcomings, such as backfilling affecting coal production efficiency, insufficient amount of gangue required for large-scale backfilling, and high cost of backfilling operations. It faces severe challenges such as the inability to achieve the green development requirements of "low carbon, zero carbon, and negative carbon". Therefore, in order to achieve near-zero ecological damage and low-carbon, zero-carbon, and negative-carbon mining goals, it is necessary to focus on innovating existing backfilling mining technology.

[0003] Based on this, the present invention proposes a negative carbon off-surface filling system layout and mining method. The invention has a simple system layout and flexible operation. It can realize rapid, efficient and high-porosity filling of underground gangue and large-scale storage of CO2, improve the efficiency and benefits of filling and mining, and has broad application prospects. Summary of the invention

[0004] Purpose of the invention: In view of the shortcomings of the prior art, the present invention provides a negative carbon off-surface filling system layout and mining method, which can solve the environmental pollution caused by ground gangue, achieve the dual purposes of solid waste disposal and coordinated CO2 storage, and realize green mining of coal resources.

[0005] To achieve the above-mentioned purpose, a negative carbon off-plane filling system arrangement and mining method of the present invention comprises the following steps:

[0006] (1) Excavate the return air uphill and transport uphill in one block, then excavate the CT101 transport level tunnel, CT101 return air level tunnel and open the cutting hole to form a complete production system;

[0007] (2) CT101 adopts post-filling technology for mining. The working face is filled as it is mined, and the goaf is filled with high-porosity filling materials such as gangue;

[0008] (3) After the backfill mining of CT101 is completed, the return air level tunnel is retained by using the gob-side tunnel retention technology, and the side tunnel support is used to reinforce it, which serves as the CO2 injection tunnel of this working face and the transportation level tunnel of CT102;

[0009] (4) Drill holes are laid from the transport tunnel of CT102 to the closed space of CT101 after backfilling and mining, and CO2 injection pipelines are laid in the transport tunnel and drill holes of CT102;

[0010] (5) CO2 is injected into the high-porosity filling material of the gangue in the goaf through the CO2 injection pipeline by the CO2 injection pump. After the CT102 filling and mining is completed, the injection of CO2 is stopped, completing a cycle of coal mining-filling-injection.

[0011] Preferably, the enclosed space is composed of the coal pillars, roadside support bodies and gangue high-porosity materials, and the enclosed space formed can prevent the leakage of CO2.

[0012] Preferably, the borehole spacing is 80 to 120 m, which facilitates the diffusion of CO2 and improves the CO2 injection efficiency.

[0013] Preferably, the CO2 injection pump is arranged in the chamber for transporting CO2 up the mountain. This arrangement can reduce the length of the CO2 injection pipeline, reduce costs, and improve the CO2 injection efficiency. The injection pump pressure is greater than 7.5MPa. Under this pressure, CO2 can reach a supercritical state underground, with high diffusivity, low viscosity and high solubility.

[0014] Preferably, the order of injecting CO2 and CT102 filling and mining is: before CT102 mining, first open the switch valve of pipeline ① to inject CO2. When the working face has mined 30 to 60 m through pipeline ①, open the switch valve of pipeline ② and close the switch valve of pipeline ①, and circulate in sequence. After the working face mining is completed, turn off the CO2 injection pump.

[0015] Beneficial effects: Compared with the prior art, the negative carbon off-plane filling system arrangement and mining method provided by the present invention has the following advantages:

[0016] 1. Using gangue solid waste as filling material can realize large-scale disposal and utilization of gangue solid waste, which is economical, green and environmentally friendly;

[0017] 2. The use of high-porosity gangue filling materials increases the porosity of the filling materials, facilitates the migration and diffusion of CO2, and improves the CO2 storage efficiency;

[0018] 3. The use of tunnel side support bodies to reinforce the tunnels along the goaf solves the problem of difficult maintenance of the tunnels along the goaf and poor sealing of the CO2 storage space. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a working face layout diagram of a negative carbon off-plane filling system arrangement and mining method of the present invention;

[0020] In the figure: 1—return air up the mountain; 2—transport up the mountain; 3—stop mining line; 4—CT101 transport level tunnel; 5—CT101 return air level tunnel; 6—CO2 injection pump; 7—CO2 filling pipeline; 8—pipeline ①; 9—pipeline ②; 10—pipeline ③; 11—pipeline ④; 12—pipeline ⑤; 13—pipeline switch valve; 14—gangue high-porosity filling material; 15—coal pillar; 16—tunnel side support body. DETAILED DESCRIPTION

[0021] The following is a detailed description of the arrangement of a negative carbon off-surface filling system and a mining method of the present invention in conjunction with the accompanying drawings.

[0022] Taking the No. 2 mining area of ​​a certain mine as an example, CT102 is currently being mined. The coal seam is buried at a depth of -800 to -1000m, with an average thickness of 3.4m and an average inclination of 8°. The roof of the coal seam is sandy mudstone, muddy siltstone and mudstone, and the old roof is often medium- and fine-grained sandstone; the bottom plate is generally mudstone, sandy mudstone, and siltstone. The working face is 150m long and the advancement length is 835m. Figure 1 As shown, the dotted line is the stop mining line, and the negative carbon off-surface filling mining process is as follows:

[0023] S1. Excavate the return air uphill tunnel (1) and the transport uphill tunnel (2) in one block, then excavate the CT101 transport tunnel (4), CT101 return air tunnel (5) and open the cut hole to form a complete production system;

[0024] S2 and CT101 adopt post-filling technology for mining, with the working face filled as it is mined, and the goaf filled with high-porosity gangue filling materials (14);

[0025] After the backfill mining of S3 and CT101 is completed, the CT101 return air level tunnel (5) is retained by using the gob-side tunnel retention technology, and is reinforced by using the side tunnel support body (16) to serve as the CO2 injection tunnel of this working face and the transportation level tunnel of CT102;

[0026] S4, drilling holes are arranged from the transport tunnel of CT102 to CT101 where the backfill mining has been completed to form a closed space, and a CO2 filling pipeline (7) is arranged in the transport tunnel of CT102 and the drilled holes; the closed space is composed of the remaining coal pillars (15), the roadside support body (16) and the gangue high-porosity material (14), and the drilling hole spacing is 100m;

[0027] S5, CO2 is injected into the high-porosity filling material (14) of the gangue in the goaf through the CO2 injection pipe (7) by the CO2 injection pump (6). After the CT102 filling and mining is completed, the injection of CO2 is stopped to complete a cycle of coal mining-filling-injection. The injection pump pressure is 7.5MPa. The sequence of injecting CO2 and CT102 filling and mining is as follows: before CT102 mining, the switch valve (13) of pipeline ① (8) is opened to inject CO2. When the working face advances 30 to 60m beyond pipeline ① (8), the switch valve (13) of pipeline ② (9) is opened and the switch valve (13) of pipeline ① (8) is closed. This operation is carried out until the CT102 mining is completed, and the CO2 injection pump is closed.

[0028] The negative carbon off-surface filling mining method used in the embodiment has a CO2 storage capacity of 213 tons and simultaneously disposes of 212,900 tons of gangue, achieving the dual purposes of solid waste disposal and CO2 storage and realizing green mining of coal resources.

[0029] The technical means disclosed in the scheme of the present invention are not limited to the technical means disclosed in the above-mentioned implementation mode, but also include technical schemes composed of any combination of the above-mentioned technical features. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also regarded as the protection scope of the present invention.

Claims

1. A negative carbon off-surface filling system arrangement and mining method, characterized in that: The steps include: S1. Excavate the return air uphill tunnel (1) and the transport uphill tunnel (2) in one block, then excavate the CT101 transport tunnel (4), CT101 return air tunnel (5) and open the cut hole to form a complete production system; S2 and CT101 adopt post-filling technology for mining, with the working face filled as it is mined, and the goaf filled with high-porosity gangue filling materials (14); During the backfill mining operation of S3 and CT101, the CT101 return air level tunnel (5) is retained by using the gob-side tunnel retention technology and reinforced by using the side tunnel support body (16) to serve as the CO2 injection tunnel of this working face and the transportation level tunnel of CT102; S4, arranging a borehole from the transport tunnel of CT102 to the CT101 which has been mined and formed into a closed space after backfilling, and arranging a CO2 filling pipeline (7) in the transport tunnel of CT102 and the borehole; S5. CO2 is injected into the high-porosity filling material (14) of the goaf by the CO2 injection pump (6) through the CO2 injection pipeline (7). After the CT102 filling and mining is completed, the injection of CO2 is stopped, completing a cycle of coal mining-filling-injection.

2. The negative carbon off-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S4, the enclosed space is composed of the remaining coal pillars (15), the roadway support body (16) and the gangue high-porosity material (14).

3. The negative carbon off-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S4, the drilling distance is 80 to 120 m.

4. The negative carbon off-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S5, the CO2 injection pump is arranged in the chamber for transporting CO2 up the mountain (2), and the injection pump pressure is greater than 7.5 MPa.

5. The negative carbon off-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S5, the sequence of CO2 injection by CT101 and filling and mining by CT102 is as follows: before mining by CT102, first open the switch valve (13) of pipeline ① (8) to inject CO2; when the working face advances 30 to 60 m beyond pipeline ① (8), open the switch valve (13) of pipeline ② (9) and close the switch valve (13) of pipeline ① (8); and follow this operation until mining by CT102 is completed, and then turn off the CO2 injection pump.

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