Preparation system and method of rock stratum grouting modified material with carbon sequestration function

Abstract

The invention discloses a preparation system and method of a rock stratum grouting modified material with a carbon sequestration function, and relates to the field of fluorine-containing wastewater treatment and fluorine resource recovery, the preparation system comprises a gas inlet mechanism, a material mixing mechanism and an atmosphere control system; the mixing mechanism is composed of a stirring barrel, a closed end cover and a stirring assembly, slurry is contained in the stirring barrel, and a gas cavity is formed above the slurry; the atmosphere control system comprises a control system, a bubbling bed, a gas circulating pump and a carbon dioxide concentration sensor; the gas circulating pump circulates gas in the gas cavity into the slurry, the carbon dioxide concentration sensor monitors the carbon dioxide concentration in the gas cavity in real time, and the control system adjusts the opening degree of the electromagnetic valve of the gas inlet mechanism according to a signal of the sensor, so that the carbon dioxide concentration in the gas cavity is kept constant. According to the preparation system and method, organic combination of efficient carbon sequestration and rock stratum modified material preparation is achieved, and the preparation system and method have the advantages of being high in carbon sequestration efficiency, controllable in carbon dioxide reaction concentration and the like.

Description

Technical Field

[0001] The present invention relates to the field of fluorine-containing wastewater treatment and fluorine resource recovery, and in particular to a system and method for preparing a rock formation grouting modified material with carbon sequestration function. Background Art

[0002] The Yellow River Basin is a rich area of ​​coal resources in my country, but also a region with a relatively fragile ecological environment. There are nine national large-scale coal bases in the basin, including Ningdong, Shendong, Shaanxi, Huanglong, Shanxi, Jinzhong, and Shanxi, accounting for about 67.4% of the country's total carbon dioxide emissions. Under the dual background of the current energy security strategic needs and the implementation of the carbon neutrality goal, the water conservation mining and low-carbon development of coal resources in the basin face unprecedented opportunities and challenges.

[0003] Rock grouting modification technology is a technology that injects functional slurry materials into the target strata to enhance the physical, mechanical and permeability properties of the barrier / aquifer. It has become a direct technical means to solve the regional governance problems of floor pressure water or shallow water protection commonly faced in coal mining. Among the coal mine rock grouting modification materials, cement-based materials are still the "main force" due to their economy and water quality protection benefits, but their slurries have shortcomings such as short slurry preparation time, single slurry particle size, and large carbon emissions from source materials. Therefore, achieving carbon sequestration of cement-based materials is a key prerequisite for low-carbon development in the field of water conservation in coal mines.

[0004] The wet carbonation process is a technology that introduces carbon dioxide gas during the slurrying and stirring stage of cement-based materials to achieve carbon sequestration of cement-based materials under normal temperature and pressure conditions. This process has significant economic advantages over the direct mineralization method, and has the advantage of long-term stable sequestration compared to traditional CCS projects. It is currently a promising technology for coal mines to expand low-carbon development. However, the slurrying time of the grouting material is short, and the carbon fixation efficiency of the slurry is a fundamental contradiction that restricts the development of this technology. For example, the Chinese invention patent with publication number CN114179223B uses a gas pipe to inject carbon dioxide gas into the cement-based slurry to be stirred, but because the bubbles inevitably move freely upward due to buoyancy, it is easy to cause a stirring blind spot in the corners of the reactor, resulting in low carbon fixation efficiency. In addition, the existing wet mineralization devices for cement-based materials mostly use a single type of bubbling method. Regardless of whether the mixing barrel is open or closed, it will cause the carbon dioxide concentration to be difficult to accurately control and the bubble particle size to be single, which will lead to unstable particle size of the associated mineralization reaction product and difficult to control the solid phase particle size grading. Summary of the invention

[0005] The purpose of the present invention is to provide a system and method for preparing a rock grouting modified material with carbon sequestration function, so as to achieve effective treatment of fluorine-containing wastewater and recovery and reuse of fluorine element.

[0006] To achieve the above objectives, in one aspect, the present invention provides a system for preparing a rock formation grouting modification material with carbon sequestration function, comprising:

[0007] An air intake mechanism, used for stably outputting a preset flow rate of carbon dioxide gas;

[0008] The mixing mechanism comprises a mixing barrel and a closed end cover arranged on the mixing barrel, wherein the mixing barrel contains slurry liquid and forms a gas cavity above the slurry liquid, wherein the gas cavity forms a gas-liquid interface at the liquid surface of the slurry liquid; the mixing barrel comprises a mixing assembly;

[0009] An atmosphere control system comprises a control system, a bubbling bed, a gas circulation pump and at least one carbon dioxide concentration sensor; the gas inlet end of the gas circulation pump is connected to the gas cavity of the stirring barrel, and the gas outlet end is connected to the bubbling bed immersed in the slurry liquid; the carbon dioxide concentration sensor is arranged in the gas cavity to monitor the carbon dioxide concentration in the gas cavity in real time;

[0010] The gas circulation pump and the carbon dioxide concentration sensor are electrically connected to a control system, and the control system controls the opening of the solenoid valve of the air intake mechanism according to a signal from the carbon dioxide concentration sensor to maintain a constant carbon dioxide concentration in the gas cavity.

[0011] The above structure aims to propose a rock grouting modification material preparation system with carbon sequestration function. Through structural design, it realizes the organic combination of efficient carbon fixation and rock modification material preparation. It has the advantages of high carbon fixation efficiency and controllable carbon dioxide reaction concentration.

[0012] Optionally, the air intake mechanism includes a carbon dioxide gas source and a switch main valve arranged at the outlet end of the carbon dioxide gas source; the switch main valve is fixedly connected to an air intake hose, and the air intake hose is connected to a pressure reducing valve, a flow valve, a flow sensor and a solenoid valve in sequence; the flow sensor and the solenoid valve are communicatively connected to a control system. Through the cooperation of the atmosphere control system and the air intake mechanism, the carbon dioxide concentration in the mixing barrel can be monitored and accurately controlled in real time to ensure that it is always within a preset constant range, thereby significantly improving the utilization rate of carbon dioxide and the carbon fixation efficiency.

[0013] Optionally, the air inlet hose passes through the closed end cover and extends along the inner wall of the stirring barrel to 5 to 8 cm above the gas-liquid interface.

[0014] Optionally, the bubbling bed is a low-pressure refined gas disc stone, which is provided with a gas supply hole for carbon dioxide gas to overflow, and the diameter of the gas supply hole is set according to the opening amount of the rock formation fissure to achieve control of the size of the calcium carbonate crystal nucleus. Uniform dispersion is achieved through the nanopores of the bubbling bed, avoiding the problems of stirring blind spots and low carbon fixation efficiency caused by the floating of bubbles in traditional methods. The diameter of the gas outlet of the bubbling bed can be flexibly adjusted according to the opening amount of the rock formation fissure, thereby achieving the regulation of the size of the calcium carbonate crystal nucleus. This design can optimize the particle size grading of the slurry, improve the mechanical properties and impermeability of the stone body, and better meet the needs of rock formation modification.

[0015] Optionally, the relationship between the diameter of the air supply hole and the opening amount of the rock formation fissure is as follows:

[0016] When the opening of rock fractures is 8μm to 10μm, the diameter of the pores is 0.8μm to 1μm;

[0017] When the opening of rock fracture is 6μm to 8μm, the diameter of air pore is 0.6μm to 0.8μm;

[0018] When the opening of rock fractures is 4μm to 6μm, the diameter of the air pore is 0.4μm to 0.6μm;

[0019] When the opening of rock fractures is 2μm to 4μm, the diameter of the air pore is 0.2μm to 0.4μm;

[0020] When the opening of rock fractures is ≤2μm, the diameter of the pores is 0.05μm to 0.2μm.

[0021] Optionally, the total gas outlet rate of the bubbling bed is 4-5 L / min, the diameter of the bubbling bed is 10-15 mm smaller than the inner diameter of the stirring barrel, and the thickness is 25-30 mm smaller than the height from the stirring blade to the bottom of the stirring barrel.

[0022] Optionally, the bubbling bed is composed of two or more equally divided circular sub-gas disks, the diameters of the gas supply holes on each of the sub-gas disks are different, and each of the sub-gas disks is connected to a different gas injection hose.

[0023] Optionally, the atmosphere control system further comprises a pressure sensor disposed in the stirring barrel, and the pressure sensor is communicatively connected to the control system.

[0024] Optionally, the system for preparing rock formation grouting modified materials with carbon sequestration function further includes a degassing and discharging mechanism, which is connected to a discharge pipe connected to the bottom of the mixing barrel; the degassing and discharging mechanism includes:

[0025] A degassing chamber for removing unreacted carbon dioxide gas from the slurry;

[0026] An ultrasonic vibration module is arranged at the center of the bottom of the degassing chamber;

[0027] A vacuum pump is connected to the degassing chamber through a degassing pipe;

[0028] The ultrasonic vibration module and the vacuum pump are both electrically connected to the control system.

[0029] Through ultrasonic vibration and vacuum extraction, unreacted carbon dioxide gas in the slurry is effectively removed, the undesirable pore structure is eliminated, and the error in analyzing the carbon fixation capacity of the grouting material is reduced, thereby improving the reliability and measurement accuracy of the system.

[0030] Optionally, the closed end cover is fixedly connected to the mixing barrel through a plurality of threaded components arranged in its circumferential direction; and a safety valve and an exhaust port are arranged on the closed end cover.

[0031] Optionally, the air inlet end of the gas circulation pump is connected to the gas cavity of the mixing barrel through an exhaust pipe, and the exhaust pipe passes through the closed end cover and extends along the inner wall of the mixing barrel to 5 to 8 cm above the gas-liquid interface.

[0032] Optionally, the carbon dioxide concentration sensor is arranged inside the closed end cover and is electrically connected to the control system through a waterproof connector.

[0033] Optionally, the stirring assembly includes a stirring motor disposed on a closed end cover, the lower end of the rotating shaft of the stirring motor is connected to a stirring rod extending into the stirring barrel, and the lower end of the stirring rod is evenly distributed with stirring blades in a circumferential direction.

[0034] On the other hand, the present invention provides a method for preparing a rock formation grouting modified material with a carbon sequestration function, using any of the above-mentioned systems for preparing a rock formation grouting modified material with a carbon sequestration function, the method comprising the following steps:

[0035] Step S501, adding grouting material into a mixing barrel according to the set material ratio and water-binder ratio, and adding a water reducer and an anti-dispersant, wherein the cementitious material ratio is 800-1350, and the water-binder ratio is 0.4-1.0;

[0036] Step S502, setting a preset threshold value β of the carbon dioxide concentration in the mixing barrel within a range of 80-100%, and injecting carbon dioxide gas into the mixing barrel by an emptying method until the carbon dioxide concentration reaches the preset threshold value β;

[0037] Step S503, start gas circulation and stirring, the gas circulation pump extracts the carbon dioxide in the gas cavity and disperses it into the slurry through the bubbling bed to realize carbon dioxide gas circulation, and stirs for 8 to 10 minutes under the gas circulation condition to obtain the mixed material;

[0038] Step S504, using negative pressure to discharge the mixed material in the mixing barrel to the degassing and discharging mechanism, and using the ultrasonic vibration module in the degassing and discharging mechanism to vibrate for 4 to 5 minutes to complete pulping;

[0039] Step S505, connecting the discharge port of the degassing and discharging mechanism to the coal mine rock formation grouting modification system, injecting grout into the modified target area, and completing carbon sequestration;

[0040] Step S506: complete the evaluation of the carbon sequestration amount M of the grouting material for carbon dioxide. The carbon sequestration amount M is calculated by the following formula:

[0041] M = (Q1-N1*V2)*1.96;

[0042] Wherein, Q1 is the total carbon dioxide intake flow recorded by the flow sensor, in L; N1 is the recorded value of the carbon dioxide concentration sensor, in %; V2 is the volume of carbon dioxide in the degassing chamber, in L.

[0043] Compared with the prior art, the present invention at least discloses the following beneficial effects:

[0044] 1. The preparation system and method of the present invention have the advantages of high carbon fixation efficiency, controllable carbon dioxide reaction concentration, and reliable structure. Compared with traditional mineralization methods and CCS projects, they have significant economic advantages and can achieve long-term and stable storage of carbon dioxide.

[0045] 2. The bubbling bed in the preparation system of the present invention can be used for rock fractures with different opening amounts. A cylindrical bubbling bed with a pore size of 0.5 to 10 mm is used to inject carbon dioxide gas into the slurry from bottom to top. The generated carbon dioxide bubbles have the characteristics of large coverage volume and controllable size, which is beneficial to the nucleation and filling effects of calcium carbonate crystals, reduces the formation of undesirable pores, and achieves the goal of improving the mechanical and anti-permeability properties of the stone body.

[0046] 3. Compared with the open direct bubbling method, the present invention can monitor and accurately control the carbon dioxide concentration in the stirring barrel in real time through the cooperation of the atmosphere control system and the carbon dioxide intake mechanism, ensuring that it is always within a preset constant range. This precise control significantly improves the utilization rate of carbon dioxide and the carbon fixation efficiency.

[0047] 4. The degassing and discharging mechanism in the preparation system of the present invention uses ultrasonic vibration to remove unreacted carbon dioxide gas from the carbon-fixed slurry, which can eliminate the undesirable pore structure in the slurry on the one hand, and reduce the error in analyzing the carbon-fixing capacity of the grouting material on the other hand.

[0048] 5. The present invention provides technical support for low-carbon development in coal-rich areas such as the Yellow River Basin, which helps to achieve carbon emission reduction targets in the coal mining process. At the same time, it protects water resources through grouting modification technology, which has important environmental significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 It is a structural schematic diagram of a preparation system according to an embodiment of the present invention;

[0051] Figure 2 Flow chart of the preparation method of an embodiment of the present invention.

[0052] Reference numerals:

[0053] 100, air intake mechanism; 101, carbon dioxide gas source; 102, switch main valve; 103, pressure reducing valve; 104, flow valve; 105, flow sensor; 106, solenoid valve; 107, air intake hose;

[0054] 200, mixing mechanism; 201, stirring motor; 202, rotating shaft; 203, stirring rod; 204, stirring blade; 205, closed end cover; 206, stirring barrel; 207, safety valve; 208, exhaust valve; 209, discharge pipe; 210, threaded member; 211, gas-liquid interface; 212, gas cavity; 213, slurry;

[0055] 300, atmosphere control system; 301, exhaust pipe; 302, gas circulation pump; 303, gas injection hose; 304, bubbling bed; 305, carbon dioxide concentration sensor 1; 306, control system;

[0056] 400. Degassing and discharging mechanism; 401. Degassing chamber; 402. Carbon dioxide concentration sensor 2; 403. Ultrasonic vibration module; 404. Discharge port; 405. Degassing pipe; 406. Vacuum pump. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0059] Embodiment 1:

[0060] Reference Figure 1 As shown, Example 1 of the present invention provides a system for preparing a rock grouting modification material with a carbon sequestration function. The preparation system includes an air intake mechanism 100, a mixing mechanism 200, and an atmosphere control system 300.

[0061] The air intake mechanism 100 is used to stably output a preset flow rate of carbon dioxide gas, and its main components include a carbon dioxide gas source 101 and a switch main valve 102 correspondingly arranged at the outlet end of the carbon dioxide gas source 101. The switch main valve 102 is fixedly connected to the air intake hose 107, and the air intake hose 107 is connected to the pressure reducing valve 103, the flow valve 104, the flow sensor 105 and the solenoid valve 106 in sequence. Among them, the flow sensor 105 and the solenoid valve 106 are both connected to the control system 306 for communication. The air intake hose 107 passes through the closed end cover 205 and extends along the inner wall of the mixing barrel 206 to 5 to 8 cm above the gas-liquid interface 211. The carbon dioxide gas source 101 is a carbon dioxide cylinder. When working, the switch main valve 102 is opened. By controlling the opening degree of the solenoid valve 106, the carbon dioxide gas supply flow rate can be accurately regulated, thereby realizing the precise control of the carbon dioxide gas supply amount of the mixing mechanism 200.

[0062] The mixing mechanism 200 includes a mixing barrel 206 with an open top and a closed end cover 205 sealed at the open end of the mixing barrel 206. A stirring assembly is arranged in the mixing barrel 206, and the stirring assembly includes a rotating shaft 202 arranged on the closed end cover 205 and a stirring motor 201 correspondingly arranged at the end of the rotating shaft 202. The lower end of the rotating shaft 202 is connected to a stirring rod 203 extending into the mixing barrel 206, and the lower end of the stirring rod 203 is uniformly distributed with stirring blades 204 in the circumferential direction. The stirring motor 201 can control the rotation speed of the stirring blades 204 to complete the stirring of the slurry. The closed end cover 205 is fixedly connected to the mixing barrel 206 through a threaded member 210, and a plurality of threaded members 210 are arranged along the circumference of the closed end cover 205. A safety valve 207 and an exhaust valve 208 are also arranged on the closed end cover 205. The mixing barrel 206 contains slurry 213, and a gas cavity 212 is formed above the slurry 213. The gas cavity 212 forms a gas-liquid interface 211 at the liquid surface of the slurry 213. The air intake mechanism 100 is connected to the gas cavity 212 through the air intake hose 107 to provide the mixing barrel 206 with stable carbon dioxide gas.

[0063] The atmosphere control system 300 includes a control system 306, a gas circulation pump 302 and a plurality of carbon dioxide concentration sensors (carbon dioxide concentration sensor 1 305 and carbon dioxide concentration sensor 2 402). The gas circulation pump 302, the carbon dioxide concentration sensor 1 305 and the carbon dioxide concentration sensor 2 402 are all electrically connected to the control system 306. The carbon dioxide concentration sensor 1 305 is arranged 2 cm inside the closed end cover 205, and is electrically connected to the control system 306 through a waterproof joint, so as to monitor the carbon dioxide concentration in the gas cavity 212 in real time. The air inlet end of the gas circulation pump 302 is connected to the gas cavity 212 of the mixing barrel 206 through the air extraction pipe 301, and the air extraction pipe 301 passes through the closed end cover 205 and extends along the inner wall of the mixing barrel 206 to 5 to 8 cm above the gas-liquid interface 211. The gas outlet end of the gas circulation pump 302 is connected to a gas injection hose 303, and the gas injection hose 303 is connected to a bubbling bed 304 immersed in the slurry liquid 213. The gas circulation pump 302 can suck the carbon dioxide gas in the gas cavity 212 into the gas injection hose 303 through the exhaust pipe 301, and then efficiently release the carbon dioxide into the grouting material through the bubbling bed 304 for sufficient carbon fixation reaction.

[0064] During operation, the control system 306 is connected to the electromagnetic valve 106 of the air intake mechanism 100 for communication. According to the signal of the carbon dioxide concentration sensor 305, the control system 306 can adjust the opening of the electromagnetic valve 106 to control the carbon dioxide gas concentration in the mixing barrel 206, and open the gas circulation pump 302 to realize the circulation of the carbon dioxide gas in the mixing barrel 206, and maintain the carbon dioxide atmosphere of constant pressure in the gas cavity 212. Compared with the traditional open direct bubbling method, the present invention uses the control system 306 to control the carbon dioxide concentration in the mixing barrel 206 in real time to ensure that it is always within a constant preset concentration range, thereby achieving efficient carbon fixation of the grouting material.

[0065] In a preferred embodiment, the bubbling bed 304 is a low-pressure refined cylindrical gas disc stone, which is provided with a gas supply hole for carbon dioxide gas to overflow, which can meet the preparation requirements of nano-scale grouting materials, obtain carbonized products with smaller diameters, achieve high-quality and efficient carbon fixation, and facilitate the generation of ultra-fine carbon fixation grouting materials, thereby achieving the purpose of grouting modification of rock formations. The diameter of the bubbling bed 304 is 10-15 mm smaller than the inner diameter of the stirring barrel 206, and the thickness of the bubbling bed 304 is 25-30 mm smaller than the height from the stirring blade 204 to the bottom of the stirring barrel 206. This size design can increase the contact area between the hydration products Ca(OH)2, C2S (Ca3SiO4) and C3S (Ca3SiO5) and carbon dioxide, prompting the slurry to fully absorb carbon dioxide and produce a large number of calcium carbonate crystal nuclei.

[0066] The total gas outlet rate of the bubbling bed 304 is 4 to 5 L / min. The diameter of the gas supply hole on the bubbling bed 304 is set according to the opening amount of the rock formation to be injected. The specific relationship is as follows:

[0067] When the opening of rock fractures is 8μm to 10μm, the diameter of the pores is 0.8μm to 1μm;

[0068] When the opening of rock fracture is 6μm to 8μm, the diameter of air pore is 0.6μm to 0.8μm;

[0069] When the opening of rock fractures is 4μm to 6μm, the diameter of the air pore is 0.4μm to 0.6μm;

[0070] When the opening of rock fractures is 2μm to 4μm, the diameter of the air pore is 0.2μm to 0.4μm;

[0071] When the opening of rock fractures is ≤2μm, the diameter of the pores is 0.05μm to 0.2μm.

[0072] Through this arrangement, the bubbling bed 304 can adjust the corresponding diameter size according to different needs, thereby better controlling the size of the calcium carbonate nucleus. For rock fractures with different opening amounts, carbon dioxide gas is injected into the slurry from bottom to top using gas supply holes with an aperture of 0.5 to 10 mm. The generated carbon dioxide bubbles have the characteristics of large coverage volume and controllable size, which is conducive to the nucleation effect and filling effect of calcium carbonate crystals, reducing the formation of undesirable pores, thereby improving the mechanical and anti-permeability properties of the stone body.

[0073] In a preferred embodiment, the bubbling bed 304 can be set to two or more, and the apertures of the air supply holes on each bubbling bed 304 are different. The air supply holes with appropriate apertures are ventilated according to the material grading requirements to flexibly adjust the particle size of the mineralized product. For example, in a specific embodiment, the bubbling bed 304 can be set to two semi-cylindrical gas disks, which are respectively connected to the gas injection hose 303 and controlled by a gas valve. In some other embodiments, the bubbling bed 304 can also be set to a plurality of equally divided circular structures, each equally divided circle is an independent sub-gas disk, and the plurality of sub-gas disks are combined into a complete cylindrical gas disk, and the apertures of the air supply holes on each sub-gas disk are different from each other.

[0074] In another optional embodiment, the bubbling bed 304 is a complete disc, but the air supply holes provided thereon include various apertures, and the air supply holes of various apertures are staggeredly distributed, and can be regularly distributed or irregularly distributed, and the air supply holes of the same aperture are connected to a gas injection hose 303. By controlling the conduction of each gas injection hose 303, switching between air supply holes of different apertures is achieved.

[0075] In a preferred embodiment, pressure sensors are respectively provided in the stirring barrel 206 and the degassing chamber 401 , and the pressure sensors are electrically connected to the control system 306 to implement servo control of the pressure in the preparation system.

[0076] In a preferred embodiment, the present invention further includes a degassing and discharging mechanism 400, which is connected to the discharge pipe 209 connected to the bottom of the mixing barrel 206. The degassing and discharging mechanism 400 includes a degassing chamber 401 and an ultrasonic vibration module 403, and the ultrasonic vibration module 403 is arranged at the bottom center of the degassing chamber 401. A carbon dioxide concentration sensor 2 402 is arranged 2 cm away from the top inside the degassing chamber 401, and the degassing chamber 401 is also equipped with a vacuum pump 406, which is connected to the degassing chamber 401 through a degassing pipe 405. The ultrasonic vibration module 403, the carbon dioxide concentration sensor 2 402 and the vacuum pump 406 are all electrically connected to the control system 306 through a data line. The degassing chamber 401 in the degassing and discharging mechanism 400 can use ultrasonic vibration to remove unreacted carbon dioxide gas for the slurry after carbon fixation. On the one hand, this can eliminate the bad pore structure in the slurry; on the other hand, it can reduce the error when analyzing the carbon fixation capacity of the grouting material.

[0077] Embodiment 2:

[0078] Reference Figure 2 As shown, Embodiment 2 of the present invention provides a method for preparing a rock formation grouting modification material having a carbon sequestration function, and the preparation method comprises the following steps:

[0079] Step S501: pour the grouting material into the mixing barrel 206 according to the set material ratio and water-binder ratio, close the sealing top cover and tighten the threaded member 210 to make the mixing barrel 206 airtight; the grouting material is at least one of ultrafine cement and ultrafine fly ash, the water reducer is polycarboxylic acid water reducer, and the anti-dispersion agent is at least one of methyl cellulose ether and polyacrylamide; the cementitious material ratio is 800, and the water-binder ratio is 0.4;

[0080] Step S502: setting the carbon dioxide concentration in the mixing barrel 206 to a preset threshold value β of 80%, and injecting carbon dioxide gas into the gas cavity 212 of the mixing barrel 206 by an emptying method; opening the switch main valve 102, controlling the electromagnetic valve 106 to open through the control system 306, and detecting the intake flow of carbon dioxide through the flow sensor 105, until the concentration detected by the carbon dioxide concentration sensor 305 in the mixing barrel 206 reaches the set carbon dioxide concentration threshold value β, and then closing the exhaust valve 208 of the mixing barrel 206;

[0081] Step S503: Turn on the gas circulation pump 302 and the stirring motor 201. When the stirring motor 201 drives the stirring blade 204 to stir, the carbon dioxide concentration in the gas cavity 212 is maintained by the atmosphere control system 300 and the air intake mechanism 100. When the value monitored by the carbon dioxide concentration sensor 305 is less than β, the control system 306 sends an opening command to the solenoid valve 106 through the data line; when the value monitored by the carbon dioxide concentration sensor 305 is equal to β, the control system 306 sends a closing command to the solenoid valve 106 through the data line; in this process, the gas circulation pump 302 extracts the carbon dioxide in the gas cavity 212 through the exhaust pipe 301 and disperses it into the slurry 213 through the gas injection hose 303 and the bubbling bed 304 to realize the circulation of carbon dioxide gas, and stirs for 8 to 10 minutes under the gas circulation condition to form a mixture; then the switch main valve 102, the solenoid valve 106 and the gas circulation pump 302 are closed in turn;

[0082] Step S504: Turn on the vacuum pump 406 and the degassing pipe 405 to evacuate the degassing chamber 401; then turn off the vacuum pump 406 and the exhaust pipe 301, open the discharge pipe 209 to discharge the mixed slurry 213 in the mixing barrel 206 into the degassing chamber 401 by negative pressure; then turn on the ultrasonic vibration module 403 to vibrate for 4 to 5 minutes to complete the slurrying and prepare for discharging;

[0083] Step S505: connecting the discharge port 404 to the coal mine rock formation grouting modification system, injecting grout into the modified target area, and completing carbon sequestration;

[0084] Step S506: Complete the evaluation of the carbon sequestration amount M of carbon dioxide by the grouting material. The carbon sequestration amount M is calculated by the following formula:

[0085] M = (Q1-N1*V2)*1.96;

[0086] Wherein, Q1 is the total carbon dioxide intake flow recorded by the flow sensor 105, in L; N1 is the recorded value of the carbon dioxide concentration sensor, in %; V2 is the volume of carbon dioxide in the degassing chamber 401, in L.

[0087] Embodiment 3:

[0088] Embodiment 3 of the present invention provides another method for preparing a rock formation grouting modification material having a carbon sequestration function, the preparation method comprising the following steps:

[0089] Step S501: pour the grouting material into the mixing barrel 206 according to the set material ratio and water-binder ratio, close the sealing top cover and tighten the threaded member 210 to make the mixing barrel 206 airtight; the grouting material is at least one of ultrafine cement and ultrafine fly ash, the water reducer is polycarboxylic acid water reducer, and the anti-dispersion agent is at least one of methyl cellulose ether and polyacrylamide; the cementitious material ratio is 1350, and the water-binder ratio is 1.0;

[0090] Step S502: setting the carbon dioxide concentration in the mixing barrel 206 to a preset threshold value β of 100%, and injecting carbon dioxide gas into the gas cavity 212 of the mixing barrel 206 by an emptying method; opening the switch main valve 102, controlling the electromagnetic valve 106 to open through the control system 306, and detecting the intake flow of carbon dioxide through the flow sensor 105, until the concentration detected by the carbon dioxide concentration sensor 305 in the mixing barrel 206 reaches the preset threshold value β of the set carbon dioxide concentration, and then closing the exhaust valve 208 of the mixing barrel 206;

[0091] Step S503: Turn on the gas circulation pump 302 and the stirring motor 201. When the stirring motor 201 drives the stirring blade 204 to stir, the carbon dioxide concentration in the gas cavity 212 is maintained by the atmosphere control system 300 and the air intake mechanism 100. When the value monitored by the carbon dioxide concentration sensor 305 is less than β, the control system 306 sends an opening command to the solenoid valve 106 through the data line; when the value monitored by the carbon dioxide concentration sensor 305 is equal to β, the control system 306 sends a closing command to the solenoid valve 106 through the data line; in this process, the gas circulation pump 302 extracts the carbon dioxide in the gas cavity 212 through the exhaust pipe 301 and disperses it into the slurry 213 through the gas injection hose 303 and the bubbling bed 304 to realize the circulation of carbon dioxide gas, and stirs for 8 to 10 minutes under the gas circulation condition to form a mixture; then the switch main valve 102, the solenoid valve 106 and the gas circulation pump 302 are closed in turn;

[0092] Step S504: Turn on the vacuum pump 406 and the degassing pipe 405 to evacuate the degassing chamber 401; then turn off the vacuum pump 406 and the exhaust pipe 301, open the discharge pipe 209 to discharge the mixed slurry 213 in the mixing barrel 206 into the degassing chamber 401 by negative pressure; then turn on the ultrasonic vibration module 403 to vibrate for 4 to 5 minutes to complete the slurrying and prepare for discharging;

[0093] Step S505: connecting the discharge port 404 to the coal mine rock formation grouting modification system, injecting grout into the modified target area, and completing carbon sequestration;

[0094] Step S506: Complete the evaluation of the carbon sequestration amount M of carbon dioxide by the grouting material. The carbon sequestration amount M is calculated by the following formula:

[0095] M = (Q1-N1*V2)*1.96;

[0096] Wherein, Q1 is the total carbon dioxide intake flow recorded by the flow sensor 105, in L; N1 is the recorded value of the carbon dioxide concentration sensor, in %; V2 is the volume of carbon dioxide in the degassing chamber 401, in L.

[0097] Embodiment 4:

[0098] Embodiment 4 of the present invention provides another method for preparing a rock formation grouting modification material having a carbon sequestration function, the preparation method comprising the following steps:

[0099] Step S501: pour the grouting material into the mixing barrel 206 according to the set material ratio and water-binder ratio, close the sealing top cover and tighten the threaded member 210 to make the mixing barrel 206 airtight; the grouting material is at least one of ultrafine cement and ultrafine fly ash, the water reducer is polycarboxylic acid water reducer, and the anti-dispersion agent is at least one of methyl cellulose ether and polyacrylamide; the cementitious material ratio is 1000, and the water-binder ratio is 0.7;

[0100] Step S502: setting the carbon dioxide concentration in the mixing barrel 206 to a preset threshold value β of 90%, and injecting carbon dioxide gas into the gas cavity 212 of the mixing barrel 206 by an emptying method; opening the switch main valve 102, controlling the electromagnetic valve 106 to open through the control system 306, and detecting the intake flow of carbon dioxide through the flow sensor 105, until the concentration detected by the carbon dioxide concentration sensor 305 in the mixing barrel 206 reaches the set carbon dioxide concentration threshold value β, and then closing the exhaust valve 208 of the mixing barrel 206;

[0101] Step S503: Turn on the gas circulation pump 302 and the stirring motor 201. When the stirring motor 201 drives the stirring blade 204 to stir, the carbon dioxide concentration in the gas cavity 212 is maintained by the atmosphere control system 300 and the air intake mechanism 100. When the value monitored by the carbon dioxide concentration sensor 305 is less than β, the control system 306 sends an opening command to the solenoid valve 106 through the data line; when the value monitored by the carbon dioxide concentration sensor 305 is equal to β, the control system 306 sends a closing command to the solenoid valve 106 through the data line; in this process, the gas circulation pump 302 extracts the carbon dioxide in the gas cavity 212 through the exhaust pipe 301 and disperses it into the slurry 213 through the gas injection hose 303 and the bubbling bed 304 to realize the circulation of carbon dioxide gas, and stirs for 8 to 10 minutes under the gas circulation condition to form a mixture; then the switch main valve 102, the solenoid valve 106 and the gas circulation pump 302 are closed in turn;

[0102] Step S504: Turn on the vacuum pump 406 and the degassing pipe 405 to evacuate the degassing chamber 401; then turn off the vacuum pump 406 and the exhaust pipe 301, open the discharge pipe 209 to discharge the mixed slurry 213 in the mixing barrel 206 into the degassing chamber 401 by negative pressure; then turn on the ultrasonic vibration module 403 to vibrate for 4 to 5 minutes to complete the slurrying and prepare for discharging;

[0103] Step S505: connecting the discharge port 404 to the coal mine rock formation grouting modification system, injecting grout into the modified target area, and completing carbon sequestration;

[0104] Step S506: Complete the evaluation of the carbon sequestration amount M of carbon dioxide by the grouting material. The carbon sequestration amount M is calculated by the following formula:

[0105] M = (Q1-N1*V2)*1.96;

[0106] Wherein, Q1 is the total carbon dioxide intake flow recorded by the flow sensor 105, in L; N1 is the recorded value of the carbon dioxide concentration sensor, in %; V2 is the volume of carbon dioxide in the degassing chamber 401, in L.

[0107] In some optional embodiments, the ratio of the cementitious material in step S501 is between 800 and 1350, and optionally, can be 800, 850, 880, 900, 960, 1000, 1250, 1350 or the like.

[0108] In some optional embodiments, the water-to-binder ratio in step S501 is between 0.4 and 1.0, and optionally, can be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, or the like.

[0109] In some optional embodiments, the predetermined value β of the carbon dioxide concentration in step S502 may be a plurality of values ​​between 80% and 100%, for example, 85%, 88%, 90%, 95%, 100%, etc.

[0110] The above parameter values ​​have been verified by experiments and can achieve the purpose of the preparation method of the present invention.

[0111] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0112] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A system for preparing rock grouting modification materials with carbon sequestration function, characterized in that: include: An air intake mechanism (100) is used to stably output a preset flow rate of carbon dioxide gas; A mixing mechanism (200) comprises a mixing barrel (206) and a closed end cover (205) arranged on the mixing barrel (206); the mixing barrel (206) contains slurry (213), and a gas cavity (212) is formed above the slurry (213); the gas cavity (212) forms a gas-liquid interface (211) at the liquid surface of the slurry (213); the mixing barrel (206) comprises a mixing assembly; An atmosphere control system (300) comprises a control system (306), a bubbling bed (304), a gas circulation pump (302) and at least one carbon dioxide concentration sensor; the gas inlet end of the gas circulation pump (302) is connected to the gas cavity (212) of the stirring barrel (206), and the gas outlet end is connected to the bubbling bed (304) immersed in the slurry liquid (213); the carbon dioxide concentration sensor is arranged in the gas cavity (212) and is used to monitor the carbon dioxide concentration in the gas cavity (212) in real time; the bubbling bed (304) is provided with a plurality of groups of gas supply holes for carbon dioxide gas to overflow, and the apertures of the gas supply holes in each group are different; The gas circulation pump (302) and the carbon dioxide concentration sensor are electrically connected to a control system (306), and the control system (306) controls the opening of the solenoid valve (106) of the air intake mechanism (100) according to a signal from the carbon dioxide concentration sensor to maintain a constant carbon dioxide concentration in the gas cavity (212).

2. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 1 is characterized in that: The air intake mechanism (100) comprises a carbon dioxide gas source (101) and a switch main valve (102) arranged at the outlet end of the carbon dioxide gas source (101); the switch main valve (102) is fixedly connected to an air intake hose (107), and the air intake hose (107) is connected in sequence to a pressure reducing valve (103), a flow valve (104), a flow sensor (105) and a solenoid valve (106); the flow sensor (105) and the solenoid valve (106) are communicatively connected to a control system (306).

3. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 2 is characterized in that: The air inlet hose (107) passes through the closed end cover (205) and extends along the inner wall of the stirring barrel (206) to a position 5 to 8 cm above the gas-liquid interface (211).

4. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 1 is characterized in that: The bubbling bed (304) is a low-pressure fine gas disc stone, and the diameter of the gas holes thereon is arranged in several groups according to the opening amount of the rock formation fissures, so as to realize the control of the size of the calcium carbonate crystal nucleus.

5. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 4 is characterized in that: The relationship between the diameter of the air supply hole and the opening amount of the rock formation fissure is as follows: When the opening of rock fractures is 8μm to 10μm, the diameter of the pores is 0.8μm to 1μm; When the opening of rock fracture is 6μm to 8μm, the diameter of air pore is 0.6μm to 0.8μm; When the opening of rock fractures is 4μm to 6μm, the diameter of the air pore is 0.4μm to 0.6μm; When the opening of rock fractures is 2μm to 4μm, the diameter of the air pore is 0.2μm to 0.4μm; When the opening of rock fractures is ≤2μm, the diameter of the pores is 0.05μm to 0.2μm.

6. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 4 is characterized in that: The total gas outlet rate of the bubbling bed (304) is 4 to 5 L / min, the diameter of the bubbling bed (304) is 10 to 15 mm smaller than the inner diameter of the stirring barrel (206), and the thickness is 25 to 30 mm smaller than the height from the stirring blade (204) to the bottom of the stirring barrel (206).

7. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 4, characterized in that: The bubbling bed (304) is composed of two or more equally divided circular sub-gas discs, the diameters of the gas supply holes on each of the sub-gas discs are different, and each of the sub-gas discs is connected to a different gas injection hose (303).

8. The system for preparing rock grouting modified materials with carbon sequestration function according to claim 1, characterized in that: The atmosphere control system (300) further comprises a pressure sensor disposed in the stirring barrel (206), and the pressure sensor is communicatively connected to the control system (306).

9. The system for preparing a rock grouting modification material with carbon sequestration function according to any one of claims 1 to 8, characterized in that: It also includes a degassing and discharging mechanism (400), which is connected to a discharge pipe (209) connected to the bottom of the mixing barrel (206); the degassing and discharging mechanism (400) includes: A degassing chamber (401) for removing unreacted carbon dioxide gas in the slurry; An ultrasonic vibration module (403) is arranged at the center of the bottom of the degassing chamber (401); A vacuum pump (406) is connected to the degassing chamber (401) through a degassing pipe (405); The ultrasonic vibration module (403) and the vacuum pump (406) are both electrically connected to the control system (306).

10. A method for preparing a rock grouting modified material with carbon sequestration function, using the system for preparing a rock grouting modified material with carbon sequestration function according to claim 9, characterized in that: The following steps are involved: Step S501, adding grouting material into the mixing barrel (206) according to the set material ratio and water-binder ratio, and adding a water reducer and an anti-dispersant, wherein the cementitious material ratio is 800-1350, and the water-binder ratio is 0.4-1.0; Step S502, setting a preset threshold value β of the carbon dioxide concentration in the mixing barrel (206) within a range of 80-100%, injecting carbon dioxide gas into the mixing barrel (206) by an emptying method until the carbon dioxide concentration reaches the preset threshold value β; at the same time, controlling the pressure in the mixing barrel (206) within a preset range P1-P2; Step S503, start gas circulation and stirring, the gas circulation pump (302) extracts the carbon dioxide in the gas cavity (212) and disperses it into the slurry (213) through the bubbling bed (304) to realize carbon dioxide gas circulation, and stirs for 8 to 10 minutes under the gas circulation condition to obtain the mixed material; Step S504, using negative pressure to discharge the mixed material in the mixing barrel (206) to the degassing and discharging mechanism (400), and using the ultrasonic vibration module (403) in the degassing and discharging mechanism (400) to vibrate for 4 to 5 minutes to complete pulping; Step S505, connecting the discharge port (404) of the degassing and discharging mechanism (400) to the coal mine rock formation grouting modification system, injecting grout into the modified target area, and completing carbon sequestration; Step S506: complete the evaluation of the carbon sequestration amount M of the grouting material for carbon dioxide. The carbon sequestration amount M is calculated by the following formula: M = (Q1-N1*V2)*1.96; In the formula, Q1 is the total carbon dioxide intake flow recorded by the flow sensor (105), unit L; N1 is the recorded value of the carbon dioxide concentration sensor, unit %; V2 is the volume of carbon dioxide in the degassing chamber (401), unit L.

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