Arrangement and mining method of negative carbon coplanar filling system

Abstract

The invention discloses a negative carbon coplanar filling system arrangement and mining method, which comprises the following steps of: stoping by adopting a rear gangue high-porosity filling coal mining technology, retaining a stoping 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; the mining roadway serves as a CO2 filling roadway of the working face and a mining roadway on one side of an adjacent filling working face; when the working face advances by 300-500 m, the working face is separated from a rear goaf through a sealing wall, and a sealed storage space is formed; then, drill holes are formed in the goaf through the CO2 injection and filling roadway, and CO2 injection and filling pipelines are arranged in the mining roadway and the drill holes; and CO2 is injected into the goaf by the CO2 injection pump through the CO2 injection pipeline, and after injection is completed, CO2 injection in the next closed space is started until injection of the working face is completed. The system is simple in arrangement, CO2 filling and coal mining filling do not interfere with each other, operation is flexible, the sealing performance of the sealing space is good, the dual purposes of solid waste disposal and CO2 sealing 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 same-face backfill system layout and mining method. Background Art

[0002] Backfill mining technology has significant technical advantages in surface subsidence control, ecological environment protection, and mine solid waste disposal and utilization. It can solve problems such as surface subsidence, groundwater loss, gas emissions, and land occupation damage from the source of coal resource mining. 2 Permanently store it underground or elsewhere to prevent it from being released into the atmosphere. Therefore, by building a confined space within the goaf, CO 2 Sealed in filling materials mainly composed of solid wastes such as coal gangue and fly ash, it can achieve large-scale disposal of solid wastes and CO 2 The dual purpose of storage.

[0003] Based on this, the present invention proposes a negative carbon same-face filling system layout and mining method, which shows that the system layout is simple, the filling and coal mining filling do not interfere with each other, and the CO 2 The sealing space has good sealing performance, which can realize the rapid and efficient high-porosity filling of underground gangue and CO 2 Large-scale storage can improve the efficiency and benefits of backfill 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 same-face filling system layout and mining method, which has a simple layout and CO 2 Filling and coal mining filling do not interfere with each other, and are widely applicable, achieving the goal of synergistic CO2 removal in solid waste disposal. 2 The dual purpose of sealing realizes the green mining of coal resources.

[0005] To achieve the above-mentioned purpose, a negative carbon same-face 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 CT301 transport level tunnel, CT301 return air level tunnel and open the cutting hole to form a complete production system;

[0007] (2) CT301 adopts the high-porosity filling technology of gangue behind the frame for coal mining, uses the gob-side tunneling technology to retain the CT301 return air tunnel, and uses the tunnel side support body to reinforce it as the CO 2 Filling tunnel and CT302 transport tunnel;

[0008] (3) When the CT301 working face advances 300-500 meters, a closed wall is used to separate the working face from the goaf behind, forming a closed CO 2 Storage space;

[0009] (4) Through CO 2 The filling tunnel is drilled into the CT301 goaf, and CO is placed in the mining tunnel and the drill hole. 2 Filling pipelines;

[0010] (5) By CO 2 The injection pump passes CO 2 Inject CO into the goaf through the filling pipeline 2 After filling, start the next confined space CO 2 of injection until the working face is filled.

[0011] Preferably, the closed wall is composed of fly ash, cement and gangue, with a thickness of 5 to 10 m, which can effectively isolate the coal mining face from the rear goaf and prevent the filling from affecting the production of the working face.

[0012] Preferably, the enclosed CO 2 The sealed space is composed of closed walls, coal pillars, roadside support bodies and high-porosity gangue materials. The closed space formed can effectively prevent CO 2 of leakage.

[0013] Preferably, the borehole spacing is greater than 300m, and each closed CO 2 A borehole is arranged in the middle of the confined space. This arrangement of boreholes is convenient for CO 2 diffusion, increasing CO 2 Injection efficiency.

[0014] Preferably, the CO 2 The injection pump is placed in the chamber for transporting gas up the mountain. This arrangement can reduce CO 2 Filling pipeline length, reducing costs and increasing CO 2 Injection efficiency: The injection pump pressure is greater than 7.5MPa. At this pressure, CO 2 It can reach a supercritical state underground, with high diffusivity, low viscosity and high solubility.

[0015] Preferably, by CO 2 The flow sensor arranged in the filling pipeline determines whether the filling is completed. 2 When the injection flow rate remains unchanged, it can be determined that CO 2 Filling is complete.

[0016] Preferably, the CT301 injects CO 2The order of backfill mining with CT301 is as follows: after CT301 is advanced to a certain distance, a closed wall is laid to form a closed space, and the switch valve (13) of pipeline ① (8) is opened to inject CO 2 After the injection is completed, close the switch valve (13) of pipeline ① (8) and proceed to the next closed space CO 2 until the working face is fully filled, and then close the CO 2 Fill pump.

[0017] Beneficial effects: Compared with the prior art, the negative carbon same-surface filling system arrangement and mining method provided by the present invention has the following advantages:

[0018] 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;

[0019] 2. Use high-porosity gangue filling materials to increase the porosity of the filling materials, making it easier for CO 2 migration and diffusion, improving CO 2 Conservation efficiency;

[0020] 3. Use closed walls to isolate the working surface from the filling space, so that CO 2 Filling and coal mining filling do not interfere with each other;

[0021] 4. Use lane side support to reinforce the lane along the goaf, solving the problem of difficult maintenance and CO 2 The problem of poor sealing of sealed space. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a working face layout diagram of a negative carbon same-face filling system arrangement and mining method of the present invention;

[0023] In the figure: 1—return air uphill; 2—transport uphill; 3—stop mining line; 4—CT301 transport lane; 5—CT301 return air lane; 6—CO 2 Injection pump; 7—CO 2 Filling pipeline; 8—Pipeline ①; 9—Pipeline ②; 10—Enclosed wall; 11—Pipeline switch valve; 12—Tunnel side support body; 13—Coal pillar; 14—Gangue high-porosity filling material; 15—Flow sensor. DETAILED DESCRIPTION

[0024] The following is a detailed description of the negative carbon same-surface filling system layout and mining method of the present invention in conjunction with the accompanying drawings.

[0025] Taking the No. 3 mining area of ​​a certain mine as an example, CT301 is currently being mined. The coal seam is buried at a depth of -750 to -1000m, with an average thickness of 3.8m and an average inclination of 6°. 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 200m long and the advancement length is 1000m. Figure 1 As shown, the dotted line is the stop mining line (3), and the negative carbon same-face filling mining process is as follows:

[0026] S1. Excavate the return air uphill (1) and the transport uphill (2) in one block, then excavate the CT301 transport tunnel (4), CT301 return air tunnel (5) and open the cut hole to form a complete production system;

[0027] S2 and CT301 adopt the high-pore filling technology of gangue after the frame for coal mining. The CT301 return air level tunnel (5) is retained by using the gob-side tunnel retention technology and reinforced by using the tunnel side support body (12) as the CO 2 Filling tunnel and CT302 transport tunnel;

[0028] When the S3 and CT301 working faces advanced 400 m, a 7 m thick closed wall (10) was used to separate the working face from the goaf behind, forming a closed CO 2 Sealed space; the closed space is composed of a retained coal pillar (13), a closed wall (10), a roadside support body (12) and a gangue high-porosity material (13);

[0029] S4. Through CO 2 The filling tunnel is drilled into the CT301 goaf, and CO is placed in the mining tunnel and the drill hole. 2 Filling pipeline, the drilling distance is 320m;

[0030] S5. By CO 2 The injection pump (6) is used to inject CO 2 The filling pipeline (7) injects CO into the goaf. 2 After filling, start the next confined space CO 2 The injection pump pressure is 7.5MPa, and CT301 injects CO 2 The order of backfill mining with CT301 is as follows: after CT301 is advanced 400m, a closed wall is laid to form a closed space, and the switch valve (11) of pipeline ① (8) is opened to inject CO 2 , when the CO in the flow sensor (15) 2 When the injection flow rate remains unchanged, it can be determined that CO 2 After filling, close the switch valve (11) of pipeline ① (8) and proceed to the next closed space CO 2until the working face is fully filled, and then close the CO 2 Fill pump (6).

[0031] Negative carbon same-face filling mining method CO used in the embodiment 2 The storage volume was 37.4 tons, and 3.4 million tons of gangue were disposed of at the same time, achieving the goal of solid waste disposal and CO 2 The dual purpose of sealing realizes the green mining of coal resources.

[0032] 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 same-face 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 CT301 transport tunnel (4), CT301 return air tunnel (5) and open the cut hole to form a complete production system; S2 and CT301 adopt the high-porosity filling mining technology of gangue after the frame for mining, and use the gob-side retaining technology to retain the CT301 return air level tunnel (5), and use the side tunnel support body (12) to reinforce it, so as to serve as the CO2 injection tunnel of this working face and the transportation level tunnel of CT302; When the S3 and CT301 working faces advance 300 to 500 m, a closed wall (10) is used to isolate the working face from the goaf behind, forming a closed CO2 storage space; S4, drilling holes into the CT301 goaf through the CO2 injection tunnel, and arranging CO2 injection pipelines (7) in the mining tunnel and the drill holes; S5. CO2 is injected into the goaf by the CO2 injection pump (6) through the CO2 injection pipeline (7). After the injection is completed, CO2 injection into the next enclosed space begins until the working face is completely filled.

2. The negative carbon same-face filling system arrangement and mining method according to claim 1 is characterized in that: In step S3, the closed wall (10) is made of fly ash, cement and gangue, and has a thickness of 5 to 10 m.

3. The negative carbon same-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S3, the enclosed CO2 storage space is composed of an enclosed wall (10), a coal pillar (13), a roadway support body (12) and a high-porosity gangue material (14).

4. The negative carbon same-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S4, the spacing between the boreholes is greater than 300m, and a borehole is arranged in each closed CO2 storage space, located in the middle of the closed space.

5. The negative carbon same-face filling system arrangement and mining method according to claim 1 is characterized in that: In step S5, the CO2 injection pump (6) is arranged in the chamber for transporting CO2 up the mountain (2), and the injection pump pressure is greater than 7.5 MPa.

6. The negative carbon same-surface filling system arrangement and mining method according to claim 1 is characterized in that: In step S5, a flow sensor (15) arranged in the CO2 filling pipeline (7) is used to determine whether the filling is completed. When the CO2 injection flow rate in the flow sensor (15) remains unchanged, it can be determined that the CO2 filling is completed.

7. The negative carbon same-face filling system arrangement and mining method according to claim 1 is characterized in that: In step S5, the sequence of CT301 injection of CO2 and CT301 backfilling and mining is as follows: after CT301 is advanced a certain distance, a closed wall (10) is laid to form a closed space, the switch valve (11) of pipeline ① (8) is opened to inject CO2, and after the injection is completed, the switch valve (11) of pipeline ① (8) is closed to inject CO2 into the next closed space, until the working face is filled and the CO2 injection pump (6) is turned off.

Images