A system and method for dynamically modeling carbon dioxide sequestration by mineralization to fill mined-out areas

Abstract

The application discloses a system and method for dynamically simulating carbon dioxide mineralization sealing and filling goaf, and belongs to the technical field of carbon dioxide mineralization sealing; the system is provided with a mineralization reaction device, a conveying device and a mineralization simulation device; the mineralization reaction device is composed of a reaction main body, an ultrasonic wave generating device and a bubble generating device; the conveying device is provided with a conveying pipeline and a pipeline monitoring device; the mineralization simulation device comprises a triaxial loading device and a heating device; the triaxial loading device is provided with a material supporting part and a loading assembly. The mineralization reaction device and the mineralization simulation device are connected through the sectional pipeline joint of the conveying device, so as to form a mineralization reaction system, and then the carbon dioxide mineralization sealing and filling goaf is dynamically simulated through the mineralization reaction system; the application is simple in simulation operation, economic and feasible, and conforms to the concept of green mining.

Description

Technical Field

[0001] This invention belongs to the field of mineralization and carbon dioxide storage technology, and more specifically, it relates to a system and method for dynamically simulating the mineralization and storage of carbon dioxide to fill goaf areas. Background Technology

[0002] Carbon dioxide emissions and their effective control have always been key concerns in various fields. The proposed carbon dioxide mineralization and sequestration offers a solution. Carbon dioxide mineralization and sequestration mainly mimics and accelerates the natural process of rock weathering and carbon dioxide absorption. Carbon dioxide dissolves in water to produce carbonic acid, which then undergoes a neutralization reaction with alkaline minerals to produce stable solid carbonates that do not decompose over long geological periods, thus achieving permanent carbon dioxide sequestration.

[0003] Given the high carbon emissions of the coal mining industry, it is essential to implement certain carbon sequestration measures. Furthermore, coal mining can cause rock strata movement and surface damage, necessitating the filling of goaf areas. However, conducting large-scale experiments on-site is subject to many limitations. Therefore, it is of great significance to simulate the mineralization and filling process of goaf areas in the laboratory and apply the experimental results to actual production. This method is convenient, economical, and in line with the concept of green mining. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing a system for dynamically simulating mineralization and sealing carbon dioxide to fill goaf areas.

[0005] To solve the above-mentioned technical problems, the present invention includes:

[0006] The mineralization reaction device consists of a reaction body, an ultrasonic generator, and a bubble generator.

[0007] The transportation equipment is equipped with transportation pipelines and pipeline monitoring devices;

[0008] And a mineralization simulation device, which includes a triaxial loading device and a heating device. The triaxial loading device is equipped with a material support and a loading component.

[0009] Preferably, the reaction body is equipped with a reaction vessel, a stirring device is installed inside the reaction vessel, an ultrasonic generator is connected to the reaction vessel through a conversion device, and a carbon dioxide cylinder is connected to the bubble generator.

[0010] Preferably, the mineralization simulation device includes a curing section, a loading section, and a molding section. The loading section has a material placement area, and a loading head and a loading baffle are provided on the outer periphery of the material placement area. The heating equipment in the molding section is located on the lower side of the loading section.

[0011] The present invention also provides a method for dynamically simulating mineralization and carbon dioxide storage for filling goaf areas, comprising the following steps:

[0012] Weigh and mix the mineralization reaction materials, and load them into the mineralization reaction device;

[0013] Water is added to a bubble generator, and then carbon dioxide is introduced to generate an aqueous solution containing micro-nano carbon dioxide bubbles, which is then introduced into a mineralization reaction device to carry out a mineralization reaction.

[0014] The fully mixed mineralized filling paste is transported through a transport device. Data on temperature and pressure within the system are collected. The filling paste at the output port is sampled and analyzed through a sampling port. The transport of the mineralized filling paste in the pipeline is monitored in real time through a pipeline monitoring device.

[0015] The mineralized filling paste is transported to the mineralization simulation device through a transport pipeline, and the airtightness of the mineralization simulation device is tested. The first sample is taken through the air outlet, and the sampled gas is analyzed for composition. Then the mineralized material is naturally cured until it is completely solidified.

[0016] At this point, a triaxial loading test is conducted. The stress conditions of the goaf are simulated by the triaxial loading equipment, and the temperature of the mineralized area of ​​the goaf is simulated by the heating equipment to change the forming environment temperature of the test block.

[0017] After the loading test is completed, gas is extracted through the vent and a second gas composition analysis is performed. The analysis results are then compared with the results of the first composition analysis.

[0018] Finally, all the gas in the mineralization simulation device was extracted through the vent, and gas composition analysis was performed to obtain the change in carbon dioxide content in the gas. The mineralization effect of the mineralization material was judged based on the change in carbon dioxide content.

[0019] Preferably, the mineralization reaction materials include water glass, fly ash, carbide slag, gangue, NaOH, NaCl, CTAB, and H2O2.

[0020] Preferably, the mass ratio of water glass, fly ash, carbide slag, and gangue in the mineralization reaction material is 3:7:3:3.

[0021] Preferably, the mineralization reaction device is connected to the mineralization simulation device through a transport device to form a test system. The test system is also equipped with an intelligent control system for intelligent control and data monitoring.

[0022] Preferably, when the mineralized filling paste is transported by the transport device, the monitoring equipment in the pipeline monitoring device and the mineralization reaction device collects data every 1 minute, and samples the filling paste at the output port of the transport device are analyzed every 5 minutes, and the paste slump and stratification change values ​​of the samples are analyzed.

[0023] Preferably, when conducting a triaxial loading test and heating the mineralization simulation device with a heating device, the temperature and pressure inside the system are monitored by a detection sensor. When the pressure inside the device remains constant for a long time, the mineralization process is considered to have ended.

[0024] Preferably, based on the known total amount of carbon dioxide in the carbon dioxide cylinder, the content of carbon dioxide introduced into the system, and the theoretically absorbed carbon dioxide content of the mineralization reaction material, the content of carbon dioxide fixed by the bubbles inside the test block after the triaxial loading test can be obtained. This value can be used to judge the mineralization effect of the mineralization material.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This invention features simple and economical simulation operation, aligning with the concept of green mining. By adding foaming agents such as hydrogen peroxide, aluminum powder, and silica fume to the mineralization reaction material, the porosity of the mineralization material after complete reaction and solidification is increased, thus expanding the filling volume. Carbon dioxide gas and water are used to generate an aqueous solution containing micro-nano carbon dioxide bubbles through a micro-nano bubble generator, which is then introduced into the mineralization reaction material to promote the mineralization reaction and increase the mineralization reaction rate. Furthermore, mechanical stirring and ultrasound are combined, utilizing the cavitation effect of ultrasound combined with mechanical stirring to further promote the mineralization reaction.

[0027] Furthermore, the transportation device employs segmented pipelines to simulate the transportation of mineralized filling paste at the filling site. A mineralization simulation device loads mineralized reaction test blocks to simulate the stress conditions of the goaf. A heating device alters the temperature of the test blocks to simulate the temperature of the mineralized area in the goaf. A triaxial loading device performs triaxial loading experiments on the test blocks in the mineralization simulation device according to the stress conditions of filling the goaf, thus ensuring that the test environment closely resembles the actual working environment, and the simulation results are feasible and effective. After loading, gas analysis is performed to determine whether the mineralized filling paste can achieve the goal of filling the goaf. This invention provides reliable theoretical guidance for actual field operations. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the mineralization reaction device of the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the transportation device of the present invention;

[0031] Figure 3 This is a top view schematic diagram of the mineralization simulation device of the present invention;

[0032] Figure 4 This is a schematic diagram of the main structure of the mineralization simulation device of the present invention.

[0033] Explanation of symbols in the diagram:

[0034] 1. Reaction vessel; 2. Mechanical stirring device; 3. Carbon dioxide microbubble generator; 4. Gas cylinder; 5. Gas control valve; 6. Flow meter; 7. Ultrasonic generator; 8. Ultrasonic transducer; 9. Pressure sensor; 10. Temperature sensor; 11. Filling pump; 12. Paste filling pipeline; 13. Conveying control valve; 14. Mineralized material transport pipeline; 15. Electromagnetic flow meter; 16. Piezoresistive pressure sensor; 17. Mineralized material sampling port; 18. Main body of the device; 19. Material placement area; 20. Triaxial loading device; 21. Triaxial loading head; 22. Triaxial loading slotted head; 23. Loading baffle; 24. Heating plate; 25. Heating plate controller; 26. Sealing cover; 27. Gas outlet; 28. Sensor interface; 29. ​​Electrochemical instrument. Detailed Implementation

[0035] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0036] Please see Figure 1 The present invention provides a system for dynamically simulating mineralization and sealing carbon dioxide filling of goaf areas, including a mineralization reaction device, a transportation device and a mineralization simulation device. The mineralization reaction device is connected to the mineralization simulation device through the transportation device to form a test system. The test system is also equipped with an intelligent control system, which can perform intelligent control and data monitoring of the system.

[0037] The mineralization reaction device consists of a reaction body, an ultrasonic generator, and a bubble generator.

[0038] Specifically, the reaction body is equipped with a reaction tank 1 for mineralizing the reaction materials; a mechanical stirring device 2 is installed inside the reaction tank 1 to promote the mineralization reaction; the upper end of the reaction tank 1 is connected to a bubble generating device installed at the outer end through a connecting pipe. The bubble generating device includes a carbon dioxide microbubble generator 3 and a gas cylinder 4. The gas cylinder 4 is connected to the carbon dioxide microbubble generator 3, and carbon dioxide is injected into the carbon dioxide microbubble generator 3 through the gas cylinder 4.

[0039] Furthermore, the bubble generating device is also equipped with a flow meter 6 and a gas control valve 5, both of which are installed on the connecting pipe connected to the outer end of the bubble generating device. The bubble generating device improves the efficiency of the mineralization reaction by introducing carbon dioxide and water into the mineralization reaction device in the form of micro-nano bubbles.

[0040] like Figure 1 As shown, the lower end of the reaction vessel 1 is connected to an ultrasonic generator via a connecting line. The ultrasonic generator includes an ultrasonic generator 7 and an ultrasonic transducer 8. The ultrasonic transducer 8 is fixedly installed at the bottom of the reaction vessel 1. The ultrasonic generator 7 is connected to the reaction vessel 1 through the ultrasonic transducer 8. The ultrasonic generator 7 can control the power of the ultrasonic waves, which can improve the mineralization effect and promote the mineralization of carbon dioxide.

[0041] Furthermore, the ultrasonic generating device 7 can be an ultrasonic generator or other ultrasonic generating equipment.

[0042] Furthermore, the reaction vessel 1 is also connected to a pressure sensor 9 and a temperature sensor 10 to monitor the reaction pressure and temperature inside the reaction vessel 1.

[0043] The reaction tank 1 is equipped with a mineralization reaction material conveying port, through which mineralization reaction materials can be added to the reaction tank 1; the bottom end of the reaction tank 1 is connected to a filling pump 11 and a paste filling pipe 12, so that the fully mixed mineralization filling paste is transported to the transportation device for transfer through the paste filling pipe 12, and a conveying control valve 13 is provided on the paste filling pipe 12 to control the conveying of the mineralization filling paste.

[0044] like Figure 2As shown, the transport device includes multiple segmented, detachable mineral material transport pipelines 14 and electromagnetic flowmeters 15 and piezoresistive pressure sensors 16 installed within the mineral material transport pipelines 14. The electromagnetic flowmeters 15 are located at the inlet of the mineral material transport pipelines 14, and a mineral material sampling port 17 is located at the outlet of the mineral material transport pipelines 14 for convenient sampling and monitoring. This transport device simulates the pipeline transport of mineral materials at a mineralized filling site, and the flow of mineral materials within the pipelines is monitored in real time by the electromagnetic flowmeters 15 and the piezoresistive pressure sensors 16.

[0045] Furthermore, multiple piezoresistive pressure sensors 16 are provided and are installed at certain intervals inside the mineral material transport pipeline 14 to monitor the pressure of the paste material transported in the pipeline.

[0046] like Figure 3 , Figure 4 As shown, the mineralization simulation device is an integrated processing device for curing, molding, and loading of mineralization reaction materials. The mineralization simulation device includes a curing section, a loading section, and a molding section, all of which are located within the main body 18 of the device. The curing section is located inside the loading section. When no loading test is conducted, the curing section is used for the natural curing of the mineralization material, and the loading section is used for the triaxial loading test of the mineralization material.

[0047] Specifically, the curing section is the material placement area 19 set inside the loading section, which is used to place mineralized materials for curing and loading tests. The loading section is equipped with a triaxial loading device 20, which is used to load and analyze the compressive strength of the solidified mineralized materials. The triaxial loading device 20 includes a triaxial loading head 21, a triaxial loading slotted head 22, a loading baffle 23, and an electrical resistivity instrument 29. The triaxial loading slotted head 22 is set at the inner end of the triaxial loading head 21 and is connected by a thread. Moreover, the loading head and the loading baffle 23 are both set on the outer periphery of the material placement area 19.

[0048] The molding section includes a heating plate 24 and a heating plate controller 25. The molding section is located below the triaxial loading device 20. The heating plate 24 of the molding section heats the mineralization simulation device. After heating, the temperature change is detected by a temperature sensor, and the heating components are adjusted to control the temperature range inside the mineralization simulation device. In addition, the heating plate 24 can be used to change the molding environment temperature of the test block to simulate the temperature of the mineralization area in the goaf.

[0049] Furthermore, in a preferred embodiment of the present invention, the heating plate 24 is a constant-temperature graphite heating plate.

[0050] Furthermore, in a preferred embodiment of the present invention, the loading baffle 23 is disposed at the inner end of the triaxial loading slotted head 22. The loading baffle 23 has a square plate structure. The triaxial loading slotted head 22 can abut against the loading baffle 23, thereby applying a loading force to the sample placed in the material placement area 19. Moreover, the triaxial loading device 20 is provided with multiple sets of loading heads and their cooperating loading baffles 23, thereby enabling triaxial loading tests to be performed on the sample.

[0051] Furthermore, the loading baffle 23 is divided into upper and lower parts. The lower loading baffle is set on the base at the lower end, and the upper and lower loading baffles are connected to the two ends of the slot of the triaxial loading slotting head 22 by threads. The triaxial loading slotting head 22 is equipped with a variety of slotting sizes and the angle is variable. Moreover, the shape and size of the loading baffle 23 are also variable, so as to accommodate the changes in the size and inclination angle of the mineralization reaction material.

[0052] Specifically, such as Figure 4 As shown, a sealing cover 26 is also provided at the upper end of the main body 18 of the device for sealing the device and ensuring its airtightness. The sealing cover 26 is provided with an air outlet 27 and a sensor interface 28. The gas inside the device is sampled and detected through the air outlet 27. The stability of the bubbles in the mineralized sample can be determined by the detection. The sensor interface 28 can be used to connect a temperature sensor and a pressure sensor for temperature and pressure monitoring. The loading process is controlled by an electrical instrument 29.

[0053] Furthermore, before closing the sealing cover 26, high-vacuum silicone grease must be applied to the contact surface between the sealing cover 26 and the loading part provided on the lower side to ensure the airtightness of the device.

[0054] Example 1

[0055] The present invention also provides a method for dynamically simulating mineralization and carbon dioxide storage for filling goaf areas, comprising the following steps:

[0056] Step 1: Connect the mineralization reaction device and the mineralization simulation device through the segmented pipe joints of the transport device to form a mineralization reaction system.

[0057] Step 2: Weigh and mix the mineralization reaction materials and load them into the mineralization reaction device.

[0058] Specifically, the mineralization reaction materials include water glass, fly ash, carbide slag, gangue, NaOH, NaCl, CTAB, and H2O2. The composition of each mineralization reaction material and its optimal ratio are shown in the table below.

[0059] Table 1. Composition and Proportioning of Mineralization Reaction Materials

[0060]

[0061] The CTAB listed in Table 1 is hexadecyltrimethylammonium bromide.

[0062] Specifically, the filling pump 11 and the conveying control valve 13 at the bottom of the reaction tank 1 are closed, and the prepared mineralizing reaction material is added into the reaction tank 1 through the mineralizing reaction material conveying port.

[0063] Step 3: Open the gas control valve 5 and the carbon dioxide microbubble generator 3 of the bubble generator. First, add a certain amount of water to the carbon dioxide microbubble generator 3, and then pass the carbon dioxide from the gas cylinder 4 into the carbon dioxide microbubble generator 3. The device generates an aqueous solution containing micro-nano carbon dioxide bubbles, and then passes it into the reaction tank 1 to start the mineralization reaction. Turn on the mechanical stirring device 2 and the ultrasonic generator 7 installed in the reaction tank 1 to improve the mineralization reaction efficiency of the reaction tank 1.

[0064] After the mineralization reaction material and carbon dioxide in the reaction tank 1 have fully reacted, the filling pump 11 and the conveying control valve 13 connected to the bottom of the reaction tank 1 are opened, and the fully mixed mineralization reaction material is transported to the mineralization simulation device in the form of paste through the paste filling pipe 12 via the transport device.

[0065] Step 4: Open the piezoresistive pressure sensor 16, electromagnetic flowmeter 15, and mineralized material sampling port 17 in the transport device to observe the transport of the mineralized filling paste in the transport pipeline. Since this system is equipped with an intelligent control system, data is collected online using the intelligent control system. During each experiment, the pressure sensor, temperature sensor, and electromagnetic flowmeter 15 collect data once every 60 seconds, and the filling paste at the output of the transport device is sampled and analyzed through the mineralized material sampling port every 5 minutes.

[0066] Specifically, by analyzing data from pressure sensors, temperature sensors, and electromagnetic flowmeters, it is determined whether the filling paste can be transported smoothly in the pipeline without clogging it. By analyzing the paste slump and stratification changes of samples from the mineralized material sampling port 17, it is determined whether the filling paste can still meet the requirements for paste pumping after long-term pipeline transportation. The transportation of the filling paste in the pipeline is monitored in real time by the piezoresistive pressure sensor 16 and the sampling port to observe whether the mineralized filling paste can be transported smoothly.

[0067] Step 5: Open the sealing cover 26 on the triaxial loading device 20, and transport the mineralized filling paste to the material placement area 19 in the mineralization simulation device through the transport pipeline. Then close the sealing cover 26 to ensure the airtightness of the device. Take the first sample through the vent 27 on the main body of the device, analyze the composition of the sampled gas using experimental instruments, record the analysis data, and then close the vent 27 to ensure the airtightness of the device.

[0068] The mineralized material was allowed to naturally cure for 12 hours. After 12 hours, the specimen had completely solidified and then a triaxial loading test could be performed.

[0069] Step 6: Open sensor interface 28 and observe the changes in temperature and pressure inside the device through temperature and pressure sensors; load the mineralization reaction block by simulating the stress conditions of the goaf through the mineralization simulation device, and change the temperature of the block through the heating plate 24 of the molding part to simulate the temperature of the mineralization area of ​​the goaf; conduct a triaxial loading experiment on the block according to the stress conditions of filling the goaf through the triaxial loading device 20, and change the molding environment temperature of the mineralization sample through the heating plate 24.

[0070] Step 7: When the sensor detects that the pressure inside the device remains constant for a long time, it can be considered that the mineralization reaction has ended. Open the vent 27 to extract the gas, collect the gas inside the device for the second time, and perform a second gas composition analysis. Compare the results of this analysis with the results of the first composition analysis.

[0071] By comparing the two sets of data, we can determine the presence of air bubbles inside the solidified specimen after a triaxial loading test of a certain intensity. Some air bubbles were destroyed after the triaxial loading, and the internal carbon dioxide gas was released, which changed the gas composition of the loading device. Therefore, the two gas analyses will be different.

[0072] Step 8: Finally, extract all the gas from the mineralization simulation device through the vent 27, perform gas composition analysis, and obtain the change in carbon dioxide content in the gas. Based on the known total amount of carbon dioxide in the carbon dioxide cylinder, the content of carbon dioxide gas introduced into the system, and the theoretically absorbable carbon dioxide content of the mineralization reaction material, the content of carbon dioxide fixed by the bubbles inside the test block after the triaxial loading test can be obtained. This value can be used to judge the mineralization effect of the mineralization material.

[0073] This not only verifies the stability of mineralized carbon dioxide, but also calculates the efficiency of carbon dioxide absorption in the mineralization reaction. The compressive strength of the mineralized test block can be determined by examining the damage of the test block after the triaxial loading test, thereby judging whether the mineralized filling material can effectively fill the goaf.

[0074] Example 2

[0075] This embodiment provides a method for dynamically simulating the filling of goaf areas with carbon dioxide in mineralized flue gas, which includes the following steps:

[0076] Step 1: Connect the mineralization reaction device and the mineralization simulation device through the segmented pipe joints of the transport device to form a mineralization reaction system.

[0077] Step 2: Weigh and mix the mineralization reaction materials and load them into the mineralization reaction device.

[0078] Specifically, the mineralization reaction materials include water glass, fly ash, carbide slag, gangue, NaOH, NaCl, CTAB, and H2O2. The composition of each mineralization reaction material and its optimal ratio are shown in the table below.

[0079] Table 2. Composition and Proportioning of Mineralization Reaction Materials

[0080]

[0081] The CTAB listed in Table 2 is hexadecyltrimethylammonium bromide.

[0082] Specifically, H2O2 is the foaming agent, and CATB is the foam stabilizer.

[0083] Specifically, the filling pump 11 and the conveying control valve 13 at the bottom of the reaction tank 1 are closed, and the prepared mineralizing reaction material is added into the reaction tank 1 through the mineralizing reaction material conveying port.

[0084] Step 3: Using dried air and pure CO2 to simulate flue gas, record the percentage of CO2 gas and set it as a.

[0085] The composition of flue gas from conventional fuel gas, oil gas, and coal gas is as follows: N2: 82%–89%, CO2: 8%–15%, O2: 3%–5%, and a small amount of SO2. Since the SO2 content is low, it is not considered in this design. Therefore, dried air and analytically pure CO2 can be used to accurately simulate the composition of flue gas. (The gas composition of normal air is as follows: N2: 78%, O2: 21%, rare gases: 0.939%, CO2: 0.031%, other gases and impurities: 0.03%).

[0086] Step 4: Open the gas control valve 5 and the carbon dioxide microbubble generator 3 of the bubble generator. First, add a certain amount of water to the carbon dioxide microbubble generator 3, and then introduce the proportioned simulated flue gas. Record the total volume of the introduced gas as V. The device generates an aqueous solution containing micro-nano carbon dioxide bubbles, and then introduces it into the reaction tank 1 to start the mineralization reaction. Turn on the mechanical stirring device 2 and the ultrasonic generator 7 installed in the reaction tank 1 to improve the mineralization reaction efficiency of the reaction tank 1.

[0087] After the mineralization reaction material and carbon dioxide in the reaction tank 1 have fully reacted, the filling pump 11 and the conveying control valve 13 connected to the bottom of the reaction tank 1 are opened, and the fully mixed mineralization reaction material is transported to the mineralization simulation device in the form of paste through the paste filling pipe 12 via the transport device.

[0088] Step 5: Open the piezoresistive pressure sensor 16, electromagnetic flowmeter 15, and mineralized material sampling port 17 in the transport device to observe the transport of the mineralized filling paste in the transport pipeline; since this system is equipped with an intelligent control system, data is collected online by the intelligent control system. During each experiment, the pressure sensor, temperature sensor, and electromagnetic flowmeter 15 collect data once every 60 seconds, and the filling paste at the output of the transport device is sampled and analyzed through the mineralized material sampling port every 5 minutes.

[0089] Specifically, by analyzing data from pressure sensors, temperature sensors, and electromagnetic flowmeters, it is determined whether the filling paste can be transported smoothly in the pipeline without clogging it. By analyzing the paste slump and stratification changes of samples from the mineralized material sampling port 17, it is determined whether the filling paste can still meet the requirements for paste pumping after long-term pipeline transportation. The transportation of the filling paste in the pipeline is monitored in real time by the piezoresistive pressure sensor 16 and the sampling port to observe whether the mineralized filling paste can be transported smoothly.

[0090] Step 6: Open the sealing cover 26 on the triaxial loading device 20, and transport the mineralized filling paste to the material placement area 19 in the mineralization simulation device through the transport pipeline. Then close the sealing cover 26 to ensure the airtightness of the device. Take the first sample through the vent 27 on the main body of the device, analyze the composition of the sampled gas using experimental instruments, record the analysis data, and then close the vent 27 to ensure the airtightness of the device.

[0091] Specifically, sampling analysis revealed that the proportion of CO2 in the gas at this point was b%. In this simulated flue gas, CO2 was the primary gas capable of chemically reacting with the mineralization reaction materials; other reactive gases were present in negligible amounts. Therefore, the remaining CO2 content in the mineralization reaction device after the reaction could be calculated from the initial CO2 proportion of a%.

[0092] The CO2 content consumed by the mineralization reaction is .

[0093] After the mineralized material was naturally cured and the test block was completely solidified, a triaxial loading test was conducted.

[0094] Step 7: Open sensor interface 28 and observe the changes in temperature and pressure inside the device through temperature and pressure sensors; load the mineralization reaction block by simulating the stress conditions of the goaf through the mineralization simulation device, and change the temperature of the block through the heating plate 24 of the molding part to simulate the temperature of the mineralization area of ​​the goaf; conduct a triaxial loading experiment on the block according to the stress conditions of filling the goaf through the triaxial loading device 20, and change the molding environment temperature of the mineralization sample through the heating plate 24.

[0095] Step 8: When the sensor detects that the pressure inside the device remains constant for a long time, it can be considered that the mineralization reaction has ended. After the loading test is completed, the mineralization reaction block is fully compressed until it is completely broken and the gas fixed by the bubbles inside the block is completely released. At this time, the compressive strength of the mineralization reaction block can be obtained through the mineralization loading device. Then, the gas is extracted through the gas outlet 27, and the gas inside the device is collected for the second time and the gas composition is analyzed for the second time. The analysis results are calculated with the first composition analysis results to obtain the CO2 gas fixed by the bubbles in the mineralization reaction block.

[0096] By comparing the two sets of data, we can determine the presence of air bubbles inside the solidified specimen after a triaxial loading test of a certain intensity. Some air bubbles were destroyed after the triaxial loading, and the internal carbon dioxide gas was released, which changed the gas composition of the loading device. Therefore, the two gas analyses will be different.

[0097] Step 9: Finally, all the gas in the mineralization simulation device is extracted through the vent 27, and the gas composition is analyzed to obtain the change in carbon dioxide content in the gas; the mineralization effect of the mineralization material is comprehensively judged by the CO2 content consumed by the mineralization reaction, the CO2 content fixed by the bubbles, and the pressure bearing condition of the mineralization test block.

[0098] This not only verifies the stability of mineralized carbon dioxide, but also calculates the efficiency of carbon dioxide absorption in the mineralization reaction. The compressive strength of the mineralized test block can be determined by examining the damage of the test block after the triaxial loading test, thereby judging whether the mineralized filling material can effectively fill the goaf.

[0099] Example 3

[0100] This embodiment provides a simulation experiment under different stress loading. The preparation process and proportioning of the mineralization reaction test block in this embodiment are the same as in Embodiment 1, specifically including the following steps:

[0101] Step 1: Weigh and mix the mineralization reaction materials and load them into the mineralization reaction device;

[0102] Step 2: Using dried air and analytically pure CO2 to simulate flue gas, record the percentage of CO2 gas as a%).

[0103] Step 3: Add water to the bubble generator, then introduce the proportioned simulated flue gas, record the total volume of the introduced gas as V carbon dioxide, thereby generating an aqueous solution containing micro-nano carbon dioxide bubbles, which is then introduced into the mineralization reaction device for mineralization reaction.

[0104] Step 4: The fully mixed mineralized filling paste is transported through a transport device. Data on temperature and pressure within the system are collected. The filling paste at the output port is sampled and analyzed through the mineralized material sampling port 17. The transport of the mineralized filling paste in the pipeline is monitored in real time through a pipeline monitoring device.

[0105] Step 5: The mineralized filling paste is transported to the mineralization simulation device via a pipeline, and the airtightness of the device is tested. A first sample is taken through the vent, and the sampled gas is analyzed. The proportion of CO2 in the gas at this point is b%. In this simulated flue gas, the main gas that can chemically react with the mineralization reaction material is CO2. The content of other reactive gases is negligible. Therefore, based on the initial proportion of CO2 (a%), the remaining CO2 content in the mineralization reaction device after the reaction can be calculated as follows:

[0106] The CO2 content consumed by the mineralization reaction is ;

[0107] The mineralized material is then allowed to naturally solidify until it is completely cured.

[0108] Step 6: The specific compressive strength of the test block can be determined through the mineralization loading experiment in Example 1. Based on the compressive strength obtained in Example 1, the compressive strength is divided into steps. The compressive strength is applied step by step from low to high using the electrical resistivity instrument 29. By analyzing the gas extracted from the vent, the degree of damage to the test block during each loading step is determined.

[0109] Example 4

[0110] This embodiment provides a secondary mineralization test under triaxial loading, and the ratio of the mineralization reaction test block is guaranteed to be the same as in Embodiment 1.

[0111] During the solidification process of the mineralization reaction test block, the stress conditions of filling the goaf were simulated to conduct a loading experiment on the test block. During the loading process, a sufficient amount of CO2 gas was introduced into the device to carry out secondary mineralization of the mineralization reaction test block under loading, thereby increasing the mineralization storage amount, improving the mineralization rate, and enhancing the mineralization effect.

[0112] After the mineralization reaction of the test block was completed in a CO2 gas environment and the test block had completely solidified, a loading test was conducted on the test block again. The compressive strength of the test block obtained from this loading test was compared with the compressive strength in the test of Example 1 to determine the degree of enhancement of the mineralization reaction by secondary mineralization.

[0113] This invention features simple and economical simulation operation, aligning with the concept of green mining. By adding foaming agents such as hydrogen peroxide, aluminum powder, and silica fume to the mineralization reaction material, the porosity of the mineralization material after complete reaction and solidification is increased, thus expanding the filling volume. Carbon dioxide gas and water are used to generate an aqueous solution containing micro-nano carbon dioxide bubbles through a micro-nano bubble generator, which is then introduced into the mineralization reaction material to promote the mineralization reaction and increase the mineralization reaction rate. Furthermore, mechanical stirring and ultrasound are combined, utilizing the cavitation effect of ultrasound combined with mechanical stirring to further promote the mineralization reaction.

[0114] Furthermore, the transportation device employs segmented pipelines to simulate the transportation of mineralized filling paste at the filling site. A mineralization simulation device loads mineralized reaction test blocks to simulate the stress conditions of the goaf. A heating device alters the temperature of the test blocks to simulate the temperature of the mineralized area in the goaf. A triaxial loading device performs triaxial loading experiments on the test blocks in the mineralization simulation device according to the stress conditions of filling the goaf, thus ensuring that the test environment closely resembles the actual working environment, and the simulation results are feasible and effective. After loading, gas analysis is performed to determine whether the mineralized filling paste can achieve the goal of filling the goaf. This invention provides reliable theoretical guidance for actual field operations.

[0115] In the description of this invention, it should be understood that terms such as “length”, “width”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, and “outer” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0116] Furthermore, in the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0117] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A system for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas, characterized in that, include: A mineralization reaction apparatus, comprising a reaction body, an ultrasonic generator, and a bubble generator; the reaction body is equipped with a reaction tank, the ultrasonic generator is connected to the reaction tank via a conversion device, the upper end of the reaction tank is connected to the bubble generator located at the outer end via a connecting pipe, and a carbon dioxide cylinder is connected to the bubble generator; the ultrasonic generator includes an ultrasonic generator and an ultrasonic transducer, the ultrasonic transducer is fixedly installed at the bottom of the reaction tank, and the ultrasonic generator is connected to the reaction tank via the ultrasonic transducer; The transportation device is equipped with a transportation pipeline and a pipeline monitoring device. The transportation pipeline includes multiple segmented, detachable, and connectable mineral material transportation pipelines. The device includes a mineralization simulation apparatus, wherein the mineralization reaction apparatus is connected to the mineralization simulation apparatus via a transport device. The mineralization simulation apparatus includes a curing section, a loading section, and a forming section. The curing section is provided with a material placement area, and a loading head and a loading baffle are provided on the outer periphery of the material placement area. The loading section is provided with a triaxial loading device, which is provided with a material support section and a loading assembly. The forming section is provided with a heating device, which is located on the lower side of the loading section.

2. The system for dynamically simulating mineralization and storing carbon dioxide for filling goaf areas according to claim 1, characterized in that, The reaction vessel is equipped with a stirring device.

3. A method for dynamically simulating mineralization and carbon dioxide storage for filling goaf areas, characterized in that, The system employs the dynamic simulation mineralization and carbon dioxide storage system for filling goaf areas as described in any one of claims 1-2, and the method includes the following steps: Weigh and mix the mineralization reaction materials, and load them into the mineralization reaction device; Water is added to the bubble generating device, and then carbon dioxide is introduced to generate an aqueous solution containing micro-nano carbon dioxide bubbles, which is then introduced into the mineralization reaction device to carry out a mineralization reaction. The fully mixed mineralized filling paste is transported through the transport device. Data on temperature and pressure within the system are collected. The filling paste at the output port is sampled and analyzed through the sampling port. The transport status of the mineralized filling paste in the pipeline is monitored in real time through the pipeline monitoring device. The mineralized filling paste is transported to the mineralization simulation device through a transport pipeline, and the airtightness of the mineralization simulation device is tested. A first sample is taken through the vent, and the sampled gas is analyzed for composition. Then, the mineralized material is allowed to naturally solidify until it is completely solidified. At this time, a triaxial loading test is carried out. The triaxial loading device is used to simulate the stress conditions of the goaf and load the test block. The heating equipment is used to change the forming environment temperature of the test block to simulate the temperature of the mineralized area of ​​the goaf. After the loading test is completed, gas is extracted through the vent and a second gas composition analysis is performed. The analysis results are then compared with the first composition analysis results. Finally, all the gas in the mineralization simulation device is extracted through the vent, and gas composition analysis is performed to obtain the change in carbon dioxide content in the gas. The mineralization effect of the mineralization material is judged based on the change in carbon dioxide content.

4. The method for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas according to claim 3, characterized in that, The mineralization reaction materials include water glass, fly ash, carbide slag, gangue, NaOH, NaCl, CTAB, and H2O2.

5. The method for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas according to claim 4, characterized in that, The mass ratio of water glass, fly ash, carbide slag, and gangue in the mineralization reaction material is 3:7:3:

3.

6. The method for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas according to claim 3, characterized in that, The mineralization reaction device is connected to the mineralization simulation device through the transport device to form a test system. The test system is also equipped with an intelligent control system for intelligent control and data monitoring.

7. The method for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas according to claim 3, characterized in that, When the mineralized filling paste is transported by the transport device, the monitoring equipment in the pipeline monitoring device and the mineralization reaction device collects data every 1 minute, and samples the filling paste at the output port of the transport device are analyzed every 5 minutes. The slump and stratification change values ​​of the paste are analyzed.

8. The method for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas according to claim 3, characterized in that, When a triaxial loading test is conducted, and the mineralization simulation device is heated by a heating device, the temperature and pressure inside the system are monitored by a detection sensor. When the pressure inside the device remains constant for a long time, the mineralization process is considered to have ended.

9. A method for dynamically simulating mineralization and sealing carbon dioxide for filling goaf areas according to claim 3, characterized in that, Based on the known total amount of carbon dioxide in the carbon dioxide cylinder, the content of carbon dioxide introduced into the system, and the theoretically absorbed carbon dioxide content of the mineralization reaction material, the content of carbon dioxide fixed by the bubbles inside the test block after the triaxial loading test can be obtained. This value can be used to judge the mineralization effect of the mineralization material.

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