Experimental equipment and method for simulating filling and sealing of carbon dioxide in goaf

Abstract

The invention provides experimental equipment and method for simulating filling and sealing of carbon dioxide in a goaf, and the experimental equipment comprises a simulation system, a slurry injection system, a gas injection system, a data acquisition and processing module, a recording, analyzing and displaying module and a data acquisition system. A simulated overlying strata of the simulation system naturally collapses to form a porous medium space model, slurry and carbon dioxide are injected into the porous medium space model through the slurry injection system and the gas injection system, and data acquisition is conducted on the curing process of the carbon dioxide through the data acquisition system; and the data is transmitted to the recording, analyzing and displaying module through the data collecting and processing module. According to the invention, the influence of carbon dioxide on the slurry solidification behavior and the solidification reaction penetration depth can be comprehensively researched, and a scientific basis is provided for optimizing material selection, proportion design and injection process parameters in practical engineering.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon emission reduction, in particular to an experimental device and method for simulating goaf filling and sealing of carbon dioxide. BACKGROUND

[0002] In recent years, goaf filling technology has been widely used. On the one hand, by injecting filling materials into the goaf, the movement of overburden rock can be effectively controlled, and the surface subsidence can be reduced. On the other hand, the resource utilization of mine solid wastes such as fly ash and slag can be realized, and the pressure of stacking can be reduced. Combining goaf filling with carbon dioxide sealing can not only play the supporting role of the filling body on the surrounding rock, but also solidify carbon dioxide by mineralization of the filling material, which becomes an innovative direction to realize subsidence control, solid waste utilization and carbon emission reduction.

[0003] At present, a simulation experiment device can be used to simulate goaf filling and sealing of carbon dioxide, so as to help understand the process of solidification of carbon dioxide by filling materials in the actual goaf. However, the existing simulation experiment device is relatively simple, and the real situation of the process of solidification of carbon dioxide by filling materials in the goaf is limited, which may cause inconvenience to understand the process of solidification of carbon dioxide by filling materials in the actual goaf. SUMMARY

[0004] The present application aims to provide an experimental device and method for simulating goaf filling and sealing of carbon dioxide, so as to simulate more realistically, and to exhibit the real situation of the process of solidification of carbon dioxide by slurry in the goaf more comprehensively by collecting various data.

[0005] The technical scheme adopted by the present application is as follows: an experimental device for simulating goaf filling and sealing of carbon dioxide, comprising a hydraulic loading device, a mining device, and a simulation box with a transparent plate arranged at the front end, wherein the hydraulic loading device is installed at the top end of the simulation box, the mining device is installed in the simulation box, and the device further comprises a simulation system, a slurry injection system, a gas injection system, a data acquisition and processing module, a recording and analysis display module, and a data acquisition system; the simulation system comprises a bottom plate, a simulated coal seam, and a simulated overburden layer arranged in the simulation box in sequence along the height direction; the mining device can sequentially mine in multiple mining areas divided along the length direction of the simulated coal seam; the slurry injection system comprises a slurry tank, a grouting pump, a flow controller, and a grouting pipeline connected in sequence; the gas injection system comprises a gas storage tank, a gas booster pump, and a gas injection pipeline connected in sequence; a protective half-pipe with a semicircular cross section and an opening downward is fixedly arranged at the lower part of the simulated overburden layer; the parts of the grouting pipeline and the gas injection pipeline extending into the simulated overburden layer are located in the protective half-pipe and can move horizontally along the length direction of the simulated coal seam; the data acquisition system comprises a high-speed camera, a gas flow sensor, and multiple data acquisition units, wherein the data acquisition units comprise a viscosity sensor, a weight sensor, an electrochemical sensor, an electrodeless resistivity meter, multiple gas concentration sensors, and an acoustic emission sensor; the data acquisition units are fixedly installed on the inner side of the simulation box corresponding to multiple unit spaces divided along the height direction in each mining area; the high-speed camera corresponds to the transparent plate; the gas flow sensor is connected to the gas injection pipeline; and the data acquisition and processing module is electrically connected to the recording and analysis display module, the viscosity sensor, the electrochemical sensor, the gas concentration sensor, the acoustic emission sensor, the high-speed camera, the weight sensor, the gas flow sensor, and the electrodeless resistivity meter.

[0006] As a preferred solution of the above-mentioned solution, the length of the simulated coal seam and the length of the mining area are 1 m and 0.1 m, respectively.

[0007] Further preferably, the material of the simulated overburden layer comprises sandstone and gypsum.

[0008] Further preferably, the porosity of the simulated overburden layer is 30%-40%.

[0009] An experimental method for simulating goaf filling and sealing of carbon dioxide, comprising the following steps:

[0010] S1, using the mining device to mine the first mining area, while controlling the hydraulic loading device to press down the simulated overburden layer; after mining is completed, a goaf is formed, the overburden in the simulated overburden layer naturally collapses and accumulates in the goaf, thereby forming a porous medium space model;

[0011] S2, moving the outlet end of the grouting pipeline and the gas injection pipeline, so that the outlet end of the grouting pipeline and the gas injection pipeline is located above the goaf;

[0012] S3, starting the grouting pump, the flow controller and the gas booster pump, the slurry in the slurry tank is injected into the porous medium space model through the grouting pipeline at a set flow rate, while the carbon dioxide in the gas storage tank is injected into the porous medium space model through the gas injection pipeline, the slurry is monitored using the electrochemical sensor, the electrodeless resistivity meter, the weight sensor and the viscosity sensor, the injected carbon dioxide flow and the carbon dioxide concentration at different positions in the unit space are monitored and collected respectively using the gas flow sensor and the plurality of gas concentration sensors, the diffusion range of the slurry in the porous medium space model and the dynamic process of occupying the pore space are monitored in real time using the high-speed camera, the data acquisition and processing module transmits the data of the high-speed camera, the electrochemical sensor, the electrodeless resistivity meter, the weight sensor, the viscosity sensor, the gas flow sensor and the gas concentration sensor to the recording, analysis and display module, and the recording, analysis and display module quantifies the initial flow diffusion law of the slurry in the goaf through the data of the weight sensor and the high-speed camera;

[0013] S4, after the slurry fills the unit space, the grouting pump and the flow controller are turned off, and the slurry reaction stage is entered, the slurry forms a slurry-overburden rock combination with the overburden rock in the goaf, the acoustic emission signal of the slurry-overburden rock combination is monitored using the acoustic emission sensor, and the data acquisition and processing module transmits the data of the acoustic emission sensor to the recording, analysis and display module;

[0014] S5, after the slurry solidifies, the gas booster pump is turned off, the slurry-overburden rock combination reacts with the carbon dioxide for a predetermined time, the recording, analysis and display module obtains a resistivity-time curve through the resistivity data transmitted by the data acquisition and processing module, and obtains the diffusion and solidification law of the slurry through the resistivity-time curve combined with the recorded pictures of the high-speed camera;

[0015] S6, repeating steps S3-S5 in the remaining unit space in the goaf from bottom to top along the height direction;

[0016] S7, repeating steps S1-S6 in the remaining mining area arranged along the length direction of the simulated coal seam;

[0017] S8, sampling the slurry-overburden rock combination in each unit space to obtain a plurality of slurry-overburden rock combination samples, and calculating the strength of the slurry-overburden rock combination samples through a uniaxial compression test;

[0018] S9, quantitatively determine the type and content of carbon dioxide solidification reaction products of the slurry-overburden combination sample, and the data acquisition and processing module transmits the data of the electrochemical sensor to the record analysis and display module, so as to obtain the penetration depth of the carbon dioxide solidification reaction;

[0019] S10, evaluate the carbon dioxide storage efficiency and solidification degree.

[0020] As a preferred embodiment of the above-mentioned scheme, after the slurry reaction stage, the slurry enters the solidification reaction stage, the data acquisition and processing module transmits the data of the acoustic emission sensor to the record analysis and display module, and the record analysis and display module reflects the damage evolution process in the slurry-overburden combination through the acoustic emission parameters in the acoustic emission sensor data, and then judges and displays the strength change process of the slurry-overburden combination through the damage evolution process in the slurry-overburden combination.

[0021] Further preferably, when the electrodeless resistivity meter detects that the resistivity of the slurry tends to be stable after changing, the slurry solidification is completed.

[0022] The beneficial effects of the present application are:

[0023] 1. By simulating the natural caving of the overburden layer and the accumulation of the overburden layer in the goaf to form a porous medium space model, and then injecting slurry and carbon dioxide into the porous medium space model to realize more realistic simulation of the carbon dioxide solidification process of the filling material in the actual goaf.

[0024] 2. The data acquisition system can collect various data during the carbon dioxide solidification process of the slurry in the goaf, so that the record analysis and display module can display the diffusion law of the slurry in the pore, the solidification process, and the migration and concentration distribution of carbon dioxide, providing rich data support for in-depth study of the mechanism and kinetics of the carbon dioxide solidification of the slurry, so as to more comprehensively show the real situation of the carbon dioxide solidification process of the slurry in the goaf, and realize the convenience of understanding the carbon dioxide solidification process of the filling material in the actual goaf.

[0025] 3. The present application can restore the complex ground stress environment and overburden dynamic caving process of the goaf by means of hydraulic loading device, mining device, simulated coal seam and simulated overburden layer, and construct a heterogeneous porous medium space model. The present application integrates mining, material injection and carbon dioxide storage process into one, realizes the whole process of coal mining and overburden caving, slurry flow diffusion, slurry solidification reaction and carbon dioxide solidification, and realizes integrated simulation research. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1It is a structural schematic view of an experimental equipment for simulating goaf filling and sealing carbon dioxide in the application.

[0027] Fig. 2 It is a structural schematic view of a simulation coal seam, a simulation overburden layer and a porous medium space model in the application. DETAILED DESCRIPTION

[0028] The application will be further described in combination with the drawings and examples.

[0029] As shown in the drawings, Figs. 1-2 An experimental equipment for simulating goaf filling and sealing carbon dioxide, comprising a hydraulic loading device 4, a mining device and a simulation box 14 provided with a transparent plate at the front end, the hydraulic loading device 4 is installed at the top end of the simulation box 14, and the mining device is installed in the simulation box 14.

[0030] The experimental equipment for simulating goaf filling and sealing carbon dioxide further comprises a simulation system, a slurry injection system, a gas injection system, a data acquisition and processing module, a recording and analysis display module and a data acquisition system.

[0031] The simulation system comprises a bottom plate 7, a simulation coal seam 6 and a simulation overburden layer 11 arranged in sequence along the height direction in the simulation box 14, and the mining device can mine in multiple mining areas divided along the length direction of the simulation coal seam 6 in sequence.

[0032] The slurry injection system comprises a slurry tank 1, a grouting pump 2, a flow controller 3 and a grouting pipeline 5 connected in sequence. The gas injection system comprises a gas storage tank 9, a gas booster pump 10 and a gas injection pipeline 8 connected in sequence.

[0033] The simulation overburden layer 11 is fixedly provided with a protective half pipe 12 with a semicircular cross section and an opening downward at the lower part, and the parts of the grouting pipeline 5 and the gas injection pipeline 8 extending into the simulation overburden layer 11 are located in the protective half pipe 12 and can move horizontally along the length direction of the simulation coal seam 6.

[0034] The data acquisition system comprises a high-speed camera, a gas flow sensor and multiple data acquisition units, the data acquisition units comprise a viscosity sensor, a weight sensor, an electrochemical sensor, an electrodeless resistivity meter, multiple gas concentration sensors and an acoustic emission sensor, the data acquisition units are fixedly installed on the inner side of the simulation box 14 corresponding to multiple unit spaces divided along the height direction in each mining area, the high-speed camera corresponds to the transparent plate, the gas flow sensor is connected to the gas injection pipeline 8, and the data acquisition and processing module is electrically connected to the recording and analysis display module, the viscosity sensor, the electrochemical sensor, the gas concentration sensor, the acoustic emission sensor, the high-speed camera, the weight sensor, the gas flow sensor and the electrodeless resistivity meter.

[0035] The electrodeless resistivity meter is used to monitor the slurry, and the high-speed camera is installed outside the simulation box 14 and monitors the inside of the simulation box 14 through the transparent plate, the weight sensor can detect the injection weight of the slurry in the unit space, and the injection volume of the slurry can be obtained in combination with the density of the slurry, and the recording and analysis display module can obtain the flow of the slurry according to the injection volume of the slurry in the unit space. The output end of the acoustic emission sensor is electrically connected with the input end of the preamplifier, and the output end of the preamplifier is electrically connected with the input end of the data acquisition and processing module. The hydraulic loading device 4, the mining device, the data acquisition and processing module and the recording and analysis display module are all prior art, and will not be described in detail here.

[0036] The protective half pipe 12 can conveniently move the outlet end of the grouting pipeline 5 and the gas injection pipeline 8 along the length direction of the simulated coal seam 6, so as to realize grouting and gas injection for each goaf.

[0037] The length of the simulated coal seam and the mining area is 1 m and 0.1 m respectively, the simulated coal seam 6 is mixed by coal powder and binder, the material of the simulated overburden layer 11 includes sandstone and gypsum, and the simulated overburden layer 11 is layered filled above the simulated coal seam 6 according to the block size distribution of 15% large blocks (particle size > 50 mm), 50% medium blocks (particle size 10-50 mm) and 35% small blocks (particle size < 10 mm) and the porosity of 30%-40%.

[0038] An experimental method for simulating goaf filling and sealing carbon dioxide, comprising the following steps:

[0039] S1, using the mining device to mine the first mining area, while controlling the hydraulic loading device 4 to press down the simulated overburden layer 11, after mining, forming a goaf, and the overburden in the simulated overburden layer 11 naturally collapses and accumulates in the goaf, thereby forming a porous medium space model 13.

[0040] The simulated coal seam 6 is mined at a rate of 0.5-1.0 m / h during mining, and the high-speed camera is used to record the dynamic collapse process of the overburden, the porous medium space model 13 is a goaf with naturally collapsed overburden, and the porous medium space model 13 can be directly used as a goaf carrier for subsequent filling and sealing experiments.

[0041] S2, moving the outlet end of the grouting pipeline 5 and the gas injection pipeline 8, so that the outlet end of the grouting pipeline 5 and the gas injection pipeline 8 is located above the goaf.

[0042] S3, start the grouting pump 2, the flow controller 3 and the gas booster pump 10, the slurry in the slurry tank 1 is injected into the porous medium space model 13 through the grouting pipeline 5 at a set flow rate, while the carbon dioxide in the gas storage tank 9 is injected into the porous medium space model 13 through the gas injection pipeline 8, the slurry is monitored using an electrochemical sensor, an electrodeless resistivity meter, a weight sensor and a viscosity sensor, the injected carbon dioxide flow and the carbon dioxide concentration at different positions in the unit space are monitored and collected respectively using a gas flow sensor and a plurality of gas concentration sensors, the diffusion range and the dynamic process of the slurry occupying the pore space in the porous medium space model 13 are monitored in real time using a high-speed camera, the data acquisition and processing module transmits the data of the high-speed camera, the electrochemical sensor, the electrodeless resistivity meter, the weight sensor, the viscosity sensor, the gas flow sensor and the gas concentration sensor to the recording, analysis and display module, and the recording, analysis and display module quantifies the initial flow diffusion law of the slurry in the goaf through the data of the weight sensor and the high-speed camera.

[0043] The slurry is prepared by mixing fly ash, slag, quartz stone and cement at a water-cement ratio of 0.8, and the weight ratio of fly ash, slag, quartz stone and cement is 4:4:1:1, and the grouting pump 2 injects the slurry into the unit space through the grouting pipeline 5 in multiple times at a flow rate of 0.3 L / min.

[0044] S4, after the slurry fills the unit space, the grouting pump 2 and the flow controller 3 are closed, and the slurry reaction stage is entered, the slurry and the overburden rock in the goaf form a slurry-overburden rock combination, the acoustic emission signal of the slurry-overburden rock combination is monitored using an acoustic emission sensor, and the data acquisition and processing module transmits the data of the acoustic emission sensor to the recording, analysis and display module.

[0045] S5, after the slurry solidifies, the gas booster pump 10 is closed, the slurry-overburden rock combination reacts with carbon dioxide for a predetermined time, the recording, analysis and display module obtains the resistivity-time curve through the resistivity data transmitted by the data acquisition and processing module, and then obtains the diffusion and solidification rules of the slurry through the resistivity-time curve combined with the recorded pictures of the high-speed camera.

[0046] S6, repeat steps S3-S5 in the remaining unit spaces in the goaf along the height direction from bottom to top.

[0047] S7, repeat steps S1-S6 in the remaining mining areas arranged along the length direction of the simulated coal seam 6.

[0048] S8, sample the slurry-overburden rock combination in each unit space to obtain a plurality of slurry-overburden rock combination samples, and calculate the strength of the slurry-overburden rock combination samples through a uniaxial compression test.

[0049] The uniaxial compression test is used to calculate the strength of the slurry-overburden combination sample, so as to quantitatively evaluate whether the mechanical strength of the rock mass after the carbon dioxide solidification and sealing meets the engineering requirements.

[0050] S9, the type and content of the carbon dioxide solidification reaction product of the slurry-overburden combination sample are quantitatively determined, the data acquisition and processing module transmits the data of the electrochemical sensor to the recording, analysis and display module, so as to obtain the penetration depth of the carbon dioxide solidification reaction.

[0051] The type and content of the carbon dioxide solidification reaction product can be quantitatively determined by comprehensively using chemical analysis and microscopic morphology observation technologies. The carbonation boundary of the slurry-overburden combination sample can be determined by using phenolphthalein titration, the un-solidified area is red, and the solidified area is colorless.

[0052] S10, the sealing efficiency and solidification degree of the carbon dioxide are evaluated.

[0053] When the sealing efficiency of the carbon dioxide is evaluated, the change of the carbon dioxide concentration is monitored by using the gas concentration sensor, and the process of the slurry solidification is monitored by using the electrodeless resistivity meter, so as to determine the amount of the carbon dioxide from the injection to the solidification sealing. The more the amount of the carbon dioxide sealed, the higher the sealing efficiency of the carbon dioxide. When the solidification degree of the carbon dioxide is evaluated, the strength of the slurry-overburden combination sample is calculated, the carbonate product and type are analyzed by using the microscopic morphology observation, and the penetration depth of the carbon dioxide solidification reaction is comprehensively evaluated, that is, the higher the strength of the slurry-overburden combination sample, the more the carbonate product and the more stable the type, and the greater the penetration depth of the carbon dioxide solidification reaction, the higher the solidification degree of the carbon dioxide, and the better the sealing effect.

[0054] After the slurry reaction stage, the slurry enters the solidification reaction stage, the data acquisition and processing module transmits the data of the acoustic emission sensor to the recording, analysis and display module, the recording, analysis and display module reflects the damage evolution process inside the slurry-overburden combination through the acoustic emission parameters in the acoustic emission sensor data, and then judges and displays the strength change process of the slurry-overburden combination through the damage evolution process inside the slurry-overburden combination.

[0055] In the solidification reaction stage, the slurry will change from a fluid to a solid with high strength and low permeability. When the electrodeless resistivity meter monitors that the resistivity of the slurry changes and then becomes stable, the solidification of the slurry is completed.

[0056] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An experimental device for simulating the backfilling and storage of carbon dioxide in a goaf, comprising a hydraulic loading device (4), a mining device and a simulation box (14) provided with a transparent plate at the front end, wherein the hydraulic loading device (4) is installed at the top end of the simulation box (14), and the mining device is installed in the simulation box (14), characterized in that: The simulation system, the slurry injection system, the gas injection system, the data acquisition and processing module, the record analysis and display module and the data acquisition system are further included. ​ The simulation system includes a bottom plate (7), a simulated coal seam (6) and a simulated overburden layer (11) arranged in sequence along the height direction in a simulation box (14), and the mining device can mine in multiple mining areas divided along the length direction of the simulated coal seam (6) in sequence. The slurry injection system includes a slurry tank (1), a grouting pump (2), a flow controller (3) and a grouting pipeline (5) connected in sequence, and the gas injection system includes a gas storage tank (9), a gas booster pump (10) and a gas injection pipeline (8) connected in sequence. The simulated overburden layer (11) is fixedly provided with a protective half pipe (12) with a semicircular cross section and an opening downward at the lower part, and the parts of the grouting pipeline (5) and the gas injection pipeline (8) extending into the simulated overburden layer (11) are located in the protective half pipe (12) and can move horizontally along the length direction of the simulated coal seam (6). The data acquisition system includes a high-speed camera, a gas flow sensor and multiple data acquisition units, the data acquisition units include a viscosity sensor, a weight sensor, an electrochemical sensor, an electrodeless resistivity meter, multiple gas concentration sensors and an acoustic emission sensor, the inside of each simulation box (14) corresponding to multiple unit spaces divided along the height direction in each mining area is fixedly provided with a data acquisition unit, the high-speed camera corresponds to a transparent plate, the gas flow sensor is connected to the gas injection pipeline (8), and the data acquisition and processing module is electrically connected to the record analysis and display module, the viscosity sensor, the electrochemical sensor, the gas concentration sensor, the acoustic emission sensor, the high-speed camera, the weight sensor, the gas flow sensor and the electrodeless resistivity meter.

2. The experimental apparatus for simulating the gob area filling and sealing of carbon dioxide according to claim 1, characterized in that: The length of the simulated coal seam and the mining area is 1 m and 0.1 m respectively.

3. The experimental apparatus for simulating the gob area filling and sealing of carbon dioxide according to claim 1, characterized in that: The material of the simulated overburden layer (11) includes sandstone and gypsum.

4. The experimental apparatus for simulating the gob area filling and sealing of carbon dioxide according to claim 3, characterized in that: The porosity of the simulated overburden layer (11) is 30%-40%.

5. An experimental method of simulating the storage of carbon dioxide by backfilling a mined-out area, characterized in that, An experimental equipment for simulating the filling and storage of carbon dioxide in a goaf according to any one of claims 1-4, comprising the following steps: S1, using the mining device to mine in the first mining area, while controlling the hydraulic loading device (4) to press downward the simulated overburden layer (11), after mining, forming a goaf, the overburden in the simulated overburden layer (11) naturally collapses and accumulates in the goaf, thereby forming a porous medium space model (13); S2, moving the outlet ends of the grouting pipeline (5) and the gas injection pipeline (8) to make the outlet ends of the grouting pipeline (5) and the gas injection pipeline (8) located above the goaf; S3, start the grouting pump (2), flow controller (3) and gas booster pump (10), the slurry in the slurry tank (1) is injected into the porous medium space model (13) through the grouting pipeline (5) at a set flow rate, while the carbon dioxide in the gas storage tank (9) is injected into the porous medium space model (13) through the gas injection pipeline (8), the slurry is monitored using the electrochemical sensor, electrodeless resistivity meter, weight sensor and viscosity sensor, the injected carbon dioxide flow and the carbon dioxide concentration at different positions in the unit space are monitored and collected respectively using the gas flow sensor and multiple gas concentration sensors, the diffusion range of the slurry in the porous medium space model (13) and the dynamic process of occupying the pore space are monitored in real time using the high-speed camera, the data acquisition and processing module transmits the data of the high-speed camera, electrochemical sensor, electrodeless resistivity meter, weight sensor, viscosity sensor, gas flow sensor and gas concentration sensor to the recording, analysis and display module, and the recording, analysis and display module quantifies the initial flow diffusion law of the slurry in the goaf through the data of the weight sensor and high-speed camera; S4, after the slurry fills the unit space, the grouting pump (2) and the flow controller (3) are closed, and the slurry reaction stage is entered, the slurry forms a slurry-overburden rock combination with the overburden rock in the goaf, the acoustic emission signal of the slurry-overburden rock combination is monitored using the acoustic emission sensor, and the data acquisition and processing module transmits the data of the acoustic emission sensor to the recording, analysis and display module; S5, after the slurry solidifies, the gas booster pump (10) is closed, the slurry-overburden rock combination reacts with carbon dioxide according to a predetermined time, the recording, analysis and display module obtains a resistivity-time curve through the resistivity data transmitted by the data acquisition and processing module, and obtains the diffusion and solidification rules of the slurry through the resistivity-time curve combined with the pictures recorded by the high-speed camera; S6, repeat steps S3-S5 in the remaining unit space in the goaf from bottom to top along the height direction; S7, repeat steps S1-S6 in the remaining mining area arranged along the length direction of the simulated coal seam (6); S8, sample the slurry-overburden rock combination in each unit space to obtain a plurality of slurry-overburden rock combination samples, and calculate the strength of the slurry-overburden rock combination sample through a uniaxial compression test; S9, quantitatively determine the type and content of the carbon dioxide solidification reaction product of the slurry-overburden rock combination sample, the data acquisition and processing module transmits the data of the electrochemical sensor to the recording, analysis and display module, so as to obtain the penetration depth of the carbon dioxide solidification reaction; S10, evaluate the carbon dioxide storage efficiency and solidification degree.

6. The experimental method for simulating the gob area filling and sealing of carbon dioxide according to claim 5, characterized in that: After the pulp reaction stage, the pulp enters the solidification reaction stage, the data acquisition processing module transmits the data of the acoustic emission sensor to the record analysis display module, the record analysis display module reflects the damage evolution process inside the pulp-overburden combination through the acoustic emission parameters in the acoustic emission sensor data, and then judges and displays the strength change process of the pulp-overburden combination through the damage evolution process inside the pulp-overburden combination.

7. The experimental method for simulating the gob area filling and sealing of carbon dioxide according to claim 6, characterized in that: When the electrodeless resistivity meter monitors that the resistivity of the slurry tends to be stable and unchanged after changing, the slurry solidification is completed.

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