Method for repairing overlying strata water flowing crack solidified by microwave-induced high-diffusivity slurry

Abstract

The invention belongs to the technical field of coal mining advance crack grouting and repairing methods, and particularly relates to an overlying strata water flowing crack repairing method for microwave-induced high-diffusivity slurry consolidation, which comprises the following steps of: determining a raw material proportioning relation and preparing a grouting material according to the crack development condition and the strength requirement of an overlying waterproof key layer on a coal mining working surface; an underground grouting pipeline is arranged in front of the coal face, and a heating device is arranged; injecting the prepared grouting material into an underground grouting pipeline through a ground slurry transportation assembly; and after grouting is completed, standing is conducted, and after standing is completed, the grouting material is heated and solidified through a heating device. According to the overlying strata water flowing crack repairing method based on microwave-induced high-diffusivity slurry consolidation, raw materials comprise a coal-based solid waste material, cement and water, and the coal-based solid waste material, the cement and the water are prepared into a grouting material through a filling station. According to the method, the high-diffusivity slurry is heated through the microwave means to achieve rapid consolidation, and barrier protection of the aquifer is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mining advance fissure grouting and repair methods, and in particular relates to a method for repairing overburden water-conducting fissures by consolidating a microwave-induced high-diffusivity slurry. Background Art

[0002] In recent years, the damage caused by coal mining to surface and groundwater has attracted great attention. Its harm is not only in terms of quantity, but also causes permanent pollution to groundwater that cannot be controlled and restored. Effective measures are urgently needed to effectively control it. Arid and semi-arid areas have the characteristics of shallow coal seams, large thickness, and thin bedrock. High-intensity coal mining is prone to form large-scale water-conducting fissures, which provide channels for aquifer-rich water to flow into the working face, causing roof water inrush accidents and groundwater resource loss. Therefore, it is crucial to effectively prevent and protect the key water-insulating layer under the aquifer in the mining area and reduce mining damage.

[0003] In response to the serious loss of water resources and frequent roof water inrush accidents, how to develop a new method for repairing overburden water-conducting fissures so that the prepared high-diffusivity slurry can not only have a good water-blocking effect and effectively block the aquifer, but also play an effective role in grouting and water plugging, so as to achieve safe, efficient and low-carbon groundwater resource protection and roof water inrush disaster prevention and control is a scientific problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the present invention is to provide a method for repairing water-conducting fractures in overburden rocks by consolidating a microwave-induced high-diffusivity slurry, so as to solve the above-mentioned problems.

[0005] To achieve the above-mentioned purpose, the present invention provides the following scheme: a method for repairing water-conducting cracks in overlying rocks by consolidating microwave-induced high-diffusivity slurry, comprising: determining the raw material ratio and preparing grouting materials according to the development of cracks in the key water-isolating layer overlying the coal mining working face and the strength requirements, laying an underground grouting pipeline in front of the coal mining working face, and providing a heating device on the underground grouting pipeline, injecting the prepared grouting material into the underground grouting pipeline through a ground slurry transport component, allowing the grouting to stand after the grouting is completed, and heating and solidifying the grouting material through a heating device after the standing is completed.

[0006] A microwave-induced high-diffusivity slurry consolidation method for repairing water-conducting fractures in overburden rock is disclosed. The raw materials include coal-based solid waste materials, cement and water. The coal-based solid waste materials, cement and water are prepared into grouting materials through a filling station.

[0007] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein underground grouting pipes are arranged in front of the coal mining face, including: arranging underground grouting pipes along the directions of the sectional return airway and the sectional conveyor roadway in front of the coal mining face, and the distance between two adjacent underground grouting pipes is 50 m to 100 m.

[0008] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein arranging underground grouting pipes along the directions of the sectional return airway and the sectional conveyor roadway in front of the coal mining face includes: drilling holes above the water-resisting key stratum of the sectional return airway and the sectional conveyor roadway, arranging the underground grouting pipes in the drilled holes, and arranging heating devices at the ends of the underground grouting pipes.

[0009] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein the ground slurry transportation assembly includes a ground grouting pipe and a grouting pump. One end of the ground grouting pipe is communicated with a filling station, the other end of the ground grouting pipe is communicated with the liquid inlet end of the grouting pump, the liquid outlet end of the grouting pump is communicated with the underground grouting pipe, and the grouting material enters the grouting pump through the ground grouting pipe and is then pumped into the underground grouting pipe by the grouting pump.

[0010] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein the standing time of the grouting material is 6 h to 12 h.

[0011] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein after the grouting is completed, it is left standing, and after the standing is completed, the grouting material is heated and solidified by a heating device, including: controlling the heating device by a heating control device to heat and solidify the grouting material in the underground grouting pipe.

[0012] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein the ratio of cement to water is greater than 0.25:1.

[0013] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein the slump of the grouting material is greater than 130 mm, the initial fluidity is greater than 180 mm, and the average uniaxial compressive strength is greater than 0.8 Mpa.

[0014] A method for repairing water-conducting fissures in overlying strata by microwave-induced consolidation of highly diffusible slurry based on the present invention, wherein the inner diameter of the underground grouting pipe is not less than 244.5 mm, and the inner diameter of the drilled hole is not less than 355.1 mm.

[0015] Compared with the prior art, the present invention has the following advantages and technical effects: According to the first weighting interval, pipes are laid from the sectional haulage gateway and the sectional return airway to the water-resisting key stratum. The ground slurry transportation assembly pumps the grouting material above the water-resisting key stratum. The slurry relies on its strong fluidity to fill the rock fissures. After the fissures are filled, a heating device is used to accelerate the hydration reaction of cement, promote the formation of hydration products in the cement slurry, improve the density of the material, and achieve rapid solidification of the slurry. The present invention provides a new idea for the repair of water-conducting fissures in overlying strata of coal mines. By heating highly diffusible slurry by microwave means to achieve rapid consolidation, it realizes the barrier protection of the aquifer, and at the same time plays a certain role in grouting water plugging, effectively protecting the coal mine water resources and the ecological environment of the mining area, and has wide practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0017] Figure 1 It is a plan view of the present invention.

[0018] Figure 2 It is a flowchart for the preparation of the grouting material of the present invention.

[0019] Figure 3 It is a schematic diagram of the heating device of the present invention.

[0020] Among them, 1. filling station; 2. ground grouting pipeline; 3. grouting pump; 4. heating control equipment; 5. underground grouting pipeline; 6. coal-based solid waste material; 7. belt conveyor; 8. vibrating feeder; 9. first crusher; 10. vibrating screen; 11. second crusher; 12. mixer; 13. grouting material; 14. transmission cable; 15. heating device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0022] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0023] Refer toFigures 1 to 3 As shown, the present invention provides a method for repairing water-conducting fissures in overlying rocks by consolidating microwave-induced high-diffusivity slurry, comprising: determining the raw material ratio according to the fissure development and strength requirements of the key water-isolating layer overlying the coal mining working face, and preparing grouting material 13, laying an underground grouting pipeline 5 in front of the coal mining working face, and providing a heating device 15 on the underground grouting pipeline 5, injecting the prepared grouting material 13 into the underground grouting pipeline 5 through a ground slurry transport component, allowing the grouting to stand after the grouting is completed, and heating and solidifying the grouting material 13 through the heating device 15 after the standing is completed.

[0024] Furthermore, the raw materials include coal-based solid waste materials 6 , cement and water, and the coal-based solid waste materials 6 , cement and water are prepared into grouting materials 13 through the filling station 1 .

[0025] The coal-based solid waste material 6 includes coal gangue and fly ash. The grouting material 13 made of coal gangue, fly ash, cement and water has excellent fluidity and can flow into tiny cracks.

[0026] The particle size of coal gangue is less than 1mm, the fly ash is secondary fly ash, the cement is 425 silicate cement, and the water is industrial water.

[0027] Furthermore, underground grouting pipes 5 are laid in front of the coal mining face, including: underground grouting pipes 5 are laid along the direction of the section return air lane and the section transport lane in front of the coal mining face, and the distance between two adjacent underground grouting pipes 5 is 50m~100m.

[0028] Furthermore, an underground grouting pipe 5 is laid along the direction of the section return air tunnel and the section transport tunnel in front of the coal mining face, including: drilling above the key waterproof layer of the section return air tunnel and the section transport tunnel, setting the underground grouting pipe 5 in the drill hole, and setting the heating device 15 at the end of the underground grouting pipe 5.

[0029] Furthermore, the ground slurry transportation component includes a ground grouting pipeline 2 and a grouting pump 3. One end of the ground grouting pipeline 2 is connected to the filling station 1, and the other end of the ground grouting pipeline 2 is connected to the liquid inlet end of the grouting pump 3. The liquid outlet end of the grouting pump 3 is connected to the underground grouting pipeline 5. The grouting material 13 enters the grouting pump 3 through the ground grouting pipeline 2, and is then pumped into the underground grouting pipeline 5 by the grouting pump 3.

[0030] Furthermore, the grouting material 13 is allowed to stand for 6 to 12 hours.

[0031] Furthermore, after the grouting is completed, the material is allowed to stand still, and after the standing still is completed, the grouting material 13 is heated and solidified by the heating device 15, including: controlling the heating device 15 to heat and solidify the grouting material 13 in the underground grouting pipe 5 by the heating control device 4.

[0032] The heating control device 4 is electrically connected to the heating device 15 through the transmission cable 14. According to the microwave induction principle, it facilitates remote control by the heating control device 4. The microwave is transmitted through the transmission cable 14, and finally the heating device 15 heats the end of the underground grouting pipeline 5, realizing the accelerated evaporation and condensation of the moisture in the slurry. The microwave can penetrate deep into the filling area, uniformly heat the slurry, and promote its solidification. The heating control device 4 is arranged underground and explosion-proof treatment is carried out, and the heating device 15 also undergoes explosion-proof treatment.

[0033] The heating control device 4 is a pipeline-type microwave continuous heating device with a microwave power of 800W. The microwave reaction temperature control range is 0 - 170°C, supporting the external circulation liquid dynamic process mode, and the flow rate range is 0 - 50 ml / min.

[0034] Furthermore, the ratio of cement to water is greater than 0.25:1.

[0035] Furthermore, the slump of the grouting material 13 is greater than 130 mm, the initial fluidity is greater than 180 mm, and the average uniaxial compressive strength is greater than 0.8 Mpa.

[0036] The uniaxial compressive strength is the compressive strength when the material solidification time is 28 h.

[0037] Furthermore, the inner diameter size of the underground grouting pipeline 5 is not less than 244.5 mm, and the inner diameter size of the borehole is not less than 355.1 mm.

[0038] The material of the underground grouting pipeline 5 is alloy steel. Two adjacent underground grouting pipelines 5 are connected by flanges. The borehole size is larger than the size of the underground grouting pipeline 5, which can realize the installation of the transmission cable 14 and the heating device 15.

[0039] The outside of the transmission cable 14 is wrapped with a rubber protective sleeve and pasted on the outer wall of the underground grouting pipeline 5. The heating device 15 is installed on the outer wall at the end of the underground grouting pipeline 5.

[0040] Example: After being washed and selected in the coal washery, the coal gangue is transported to the gangue hill by the belt conveyor 7, and then transported to the filling station 1 by the belt conveyor 7. The coal gangue is fed into the jaw crusher 9 through the vibrating feeder 8 for primary screening to obtain coal gangue with a particle size less than 20 mm. Then, the particle size screening is carried out by the vibrating screen 10. If the particle size is less than 1 mm, it directly skips the crushing process. The coal gangue with a particle size greater than 1 mm is transported to the impact crusher 11 and the jaw crusher 9 by the belt conveyor 7 for secondary crushing. Then, secondary screening is carried out for particle size differentiation. The coal gangue particles with a particle size less than 1 mm are transported to the mixer 12 by the belt conveyor 7 and mixed with class II fly ash, 425 Portland cement and water to prepare the grouting material 13. The slump of the grouting material 13 is greater than 130 mm, the initial fluidity is greater than 180 mm, and the average uniaxial compressive strength is greater than 0.8 Mpa.

[0041] In the front section return airway and the front section transport airway of the coal mining face in the coal mine, boreholes and underground grouting pipelines 5 are arranged at intervals of 50 m - 80 m along the strike. When the distance between the water - resisting key stratum and the ground surface is less than 600 m, ground borehole grouting is selected. When the vertical distance between the water - resisting key stratum and the mined coal seam is less than 100 m, underground borehole grouting is selected.

[0042] After the grouting material 13 fills the cracks and stands still for 6 h - 12 h, according to the principle of microwave induction, it is remotely controlled by the heating control device 4. Microwaves are transmitted through the transmission cable 14, and finally heated by the heating device 15 at the end of the underground grouting pipeline 5 to accelerate the evaporation and condensation of the moisture in the slurry. The microwaves can penetrate deep into the filling area to uniformly heat the slurry and promote its solidification. The underground grouting pipeline 5 is arranged in the section roadway, the heating control device 4 is arranged underground and explosion - proof treatment is carried out, and the heating device 15 is also subjected to explosion - proof treatment.

[0043] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationship shown in the drawings. It is 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. Therefore, it should not be construed as a limitation to the present invention.

[0044] The above - described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for repairing water-conducting fractures in overburden rock by consolidating a microwave-induced high-diffusivity slurry, characterized in that: include According to the crack development and strength requirements of the key water-proof layer overlying the coal mining face, determine the raw material ratio and prepare the grouting material (13); An underground grouting pipeline (5) is laid in front of the coal mining working face, and a heating device (15) is provided on the underground grouting pipeline (5); Injecting the prepared grouting material (13) into the underground grouting pipeline (5) through the surface slurry transport component; After the grouting is completed, the material is allowed to stand still, and after the standing still is completed, the grouting material (13) is heated and solidified by a heating device (15).

2. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 1, characterized in that: The raw materials include coal-based solid waste materials (6), cement and water, and the coal-based solid waste materials (6), cement and water are prepared into grouting materials (13) through a filling station (1).

3. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 1, characterized in that: The underground grouting pipeline (5) is arranged in front of the coal mining working face, comprising: An underground grouting pipeline (5) is arranged along the direction of the section return air lane and the section transport lane in front of the coal mining face, and the distance between two adjacent underground grouting pipelines (5) is 50m to 100m.

4. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 3, characterized in that: The underground grouting pipeline (5) is arranged along the direction of the section return air lane and the section transport lane in front of the coal mining face, comprising: A hole is drilled above the water-insulating key layer of the section return air lane and the section transport lane, an underground grouting pipeline (5) is arranged in the drilled hole, and a heating device (15) is arranged at the end of the underground grouting pipeline (5).

5. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 2, characterized in that: The surface slurry transport component comprises a surface grouting pipeline (2) and a grouting pump (3); one end of the surface grouting pipeline (2) is connected to the filling station (1); the other end of the surface grouting pipeline (2) is connected to the liquid inlet end of the grouting pump (3); the liquid outlet end of the grouting pump (3) is connected to the underground grouting pipeline (5); the grouting material (13) enters the grouting pump (3) through the surface grouting pipeline (2) and is then pumped into the underground grouting pipeline (5) by the grouting pump (3).

6. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 1, characterized in that: The grouting material (13) is allowed to stand for 6 h to 12 h.

7. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 1, characterized in that: After the grouting is completed, the grouting material (13) is allowed to stand still, and after the standing still is completed, the grouting material (13) is heated and solidified by a heating device (15), comprising: The heating device (15) is controlled by the heating control equipment (4) to heat and solidify the grouting material (13) in the underground grouting pipeline (5).

8. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 2, characterized in that: The ratio of cement to water is greater than 0.25:

1.

9. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 1, characterized in that: The slump of the grouting material (13) is greater than 130 mm, the initial fluidity is greater than 180 mm, and the average uniaxial compressive strength is greater than 0.8 MPa.

10. The method for repairing water-conducting fractures in overburden rock by microwave-induced high-diffusivity slurry consolidation according to claim 4, characterized in that: The inner diameter of the underground grouting pipe (5) shall not be less than 244.5 mm, and the inner diameter of the borehole shall not be less than 355.1 mm.

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