Device and method for mineralizing CO2 in flue gas by using solid waste

Abstract

The invention discloses a device and a method for mineralizing CO2 in flue gas by using solid waste, and belongs to the technical field of carbon sequestration. The mineralization reactor is provided with a nozzle and a microbubble generator, solid waste slurry enters the mineralization reactor through the nozzle in a jet flow mode, and flue gas enters the mineralization reactor through the microbubble generator in a microbubble mode; microbubbles can be reserved for a longer time, meanwhile, a large amount of gas-liquid phase interface area is provided, the turbulent mixing degree of gas and liquid can be increased and the updating frequency of the gas-liquid phase interface can be increased by slurry in a jet flow mode, CO2 in flue gas can be fully absorbed and reacted under the combined action of the slurry and the gas-liquid phase interface, the mineralization efficiency is remarkably improved, and the energy consumption is reduced. And the obtained carbonate product is small in particle size and high in quality.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon sequestration, and in particular relates to a device and method for utilizing CO2 in solid waste mineralization flue gas. Background Art

[0002] As one of the important technologies of CCUS (carbon capture, utilization and storage), CO2 mineralization technology uses calcium-magnesium-based minerals or solid waste to absorb CO2 to form carbonates, which is a thermodynamically favorable process. This process can safely store CO2 through chemical reactions, and has the characteristics of low environmental risk, low energy consumption, and high scale feasibility. At the same time, the resource and energy utilization process is accompanied by a large amount of solid waste containing calcium and magnesium, which seriously affects the ecological environment. Therefore, combining CO2 mineralization with solid waste can not only achieve the coordinated emission reduction of solid waste and CO2, but also produce high-value products such as carbonates or building materials, which has significant economic and environmental benefits.

[0003] In the CO2 mineralization process, it is an extremely slow process under natural conditions due to the limitations of kinetic mass transfer, among which the precipitation of alkaline earth metal ions and the diffusion rate of carbon dioxide have a great influence on the rate of mineralization reaction. Under low mineralization efficiency, CO2 in flue gas is difficult to be fully absorbed, and at the same time, alkaline substances in calcium-magnesium-based minerals or solid waste are difficult to react completely, which makes the mineralization process have the problems of long reaction time and high energy consumption of cyclic operation, which is also the main reason for limiting the scale-up of solid waste mineralization CO2 process. In response to this problem, researchers proposed an indirect mineralization process, that is, first using a leaching agent to leach calcium and magnesium ions in solid waste, and then passing CO2 into the leaching solution to undergo a mineralization reaction and generate carbonate precipitation. However, considering that the use of leaching agents will lead to increased costs and reduced process economy, the method of directly dissolving solid waste in water has gradually been adopted. However, it is difficult to complete the leaching of alkaline substances in solid waste, and the reaction efficiency of the mineralization process is slow, resulting in a certain alkalinity of solid waste after mineralization treatment, and direct storage will still cause environmental pollution.

[0004] Therefore, it is urgent to develop a green, high-mass transfer efficiency and high-reaction efficiency CO2 mineralization method to achieve the recycling of resources. Summary of the invention

[0005] In view of the above-mentioned prior art, the present invention discloses a device and method for utilizing CO2 in solid waste mineralization flue gas to solve the technical problems of low gas-liquid mass transfer rate and mineralization reaction efficiency between solid waste slurry and CO2 in the existing CO2 mineralization technology.

[0006] The technical solution adopted to solve the technical problem is to provide a device for utilizing CO2 in solid waste mineralization flue gas, which includes a mineralization reactor, a nozzle for spraying solid waste slurry is arranged on the top of the mineralization reactor, a microbubble generator for passing flue gas into the mineralization reactor in the form of microbubbles is arranged at the bottom, and a baffle is arranged on the side wall; the baffle is located at 0.7~0.8 times the height of the mineralization reactor; a slurry outlet is arranged at the lower end of the side wall of the mineralization reactor; a temperature sensor is arranged on the inner wall of the mineralization reactor, and a temperature regulation system is arranged on the outer wall.

[0007] Based on the above technical solution, the present invention can also be improved as follows.

[0008] Furthermore, there are no less than three nozzles and microbubble generators, which are evenly spaced and distributed on the central axis of the mineralization reactor.

[0009] Furthermore, the length of the baffle is equivalent to the width of the side wall of the mineralization reactor; the width of the baffle is 1 / 10 to 1 / 8 of the length of the mineralization reactor.

[0010] Furthermore, the baffle is arranged on the side wall of the mineralization reactor in a downwardly inclined manner.

[0011] Furthermore, the temperature regulating system includes a cold source and a hot source for regulating the temperature of the mineralization reactor.

[0012] The present invention also discloses a method for utilizing solid waste to mineralize CO2 in flue gas. The method is performed using the above-mentioned device and comprises the following steps: S1: mixing solid waste powder and water to obtain slurry; S2: The slurry is introduced into the mineralization reactor through a nozzle in the form of a jet, and the flue gas containing CO2 is introduced into the mineralization reactor in the form of microbubbles through a microbubble generator, and the temperature in the mineralization reactor is controlled at 20-50°C, and the reaction is kept warm for 10-20 minutes; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet, filtered and dried to obtain carbonate.

[0013] Furthermore, the solid waste is calcined phosphate tailings, the calcination temperature is 700-900°C, and the calcination time is 1-4h.

[0014] Furthermore, the particle size of the solid waste powder is less than 300 μm; and the mass ratio of the solid waste powder to water is 1:10~20.

[0015] Furthermore, the pH of the slurry is ≥10.

[0016] Furthermore, in step S2, the jet velocity is 0.5-5 m / s; the diameter of the microbubbles is less than 50 μm; the speed at which the microbubbles enter the reactor is 0.2-0.5 m / s; and the concentration of CO2 in the flue gas is 5-100 wt%.

[0017] The beneficial effects of the above technical solution adopted by the present invention are as follows: the mixing effect of slurry and microbubbles is more comprehensive and uniform, and the mixing reaction process is accelerated, thereby improving the mineralization efficiency. The rising speed of microbubbles is related to the diameter of the microbubbles. When the diameter of the microbubbles is less than 50 μm, the rising speed is appropriate and can exist stably for a long time, which is beneficial to improving the mineralization efficiency; when the diameter of the microbubbles is less than 50 μm, the surface of the microbubbles is negatively charged, which can increase the reaction efficiency with the metal ions in the slurry, and can affect the morphology and structure of the carbonate product, thereby facilitating the acquisition of carbonate products with small particle size and high quality.

[0018] The present invention has the following beneficial effects: 1. Microbubble generators and nozzles are arranged at the top and bottom of the mineralization reactor, and then CO2 and phosphate tailings slurry are introduced into the mineralization reactor by two enhanced methods, namely microbubbles and slurry jets. CO2 in the form of microbubbles can provide a large amount of gas-liquid interface area, and microbubbles will undergo interface instability phenomena such as aggregation during the floating process, and can be retained for a longer time. The slurry enters the mineralization reactor in the form of a jet, which can increase the turbulent mixing degree between CO2 and the slurry and accelerate the renewal frequency of the gas-liquid interface. Under the joint action of the two, the contact area and contact time of the gas-liquid two phases of the microbubbles and the phosphate tailings slurry are increased, the mass transfer process is enhanced, the CO2 in the flue gas can be fully absorbed and reacted, and the reaction efficiency of the phosphate tailings slurry absorption-mineralization CO2 is significantly improved, and a small-particle-size, high-quality carbonate product is obtained.

[0019] 2. The method for mineralizing CO2 using phosphate tailings of the present invention is simple to operate and has high mineralization efficiency. The mineralization efficiency of the phosphate tailings slurry can be increased from 20% to more than 95% in 10 minutes. After mineralization, a magnesium bicarbonate solution and calcium carbonate crystals with a smaller particle size are obtained. The magnesium bicarbonate solution can be separated by filtration, and the fine calcium carbonate crystals and the remaining solids can be separated by cyclone, thereby achieving the removal of calcium and magnesium components in the phosphate tailings. The P2O5 content in the tailings is enriched to more than 2 times, and the tailings can be used as a raw material for phosphate fertilizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a front view of the CO2 device in the flue gas of solid waste mineralization, where: 1. mineralization reactor; 2. nozzle; 3. nozzle; 4. microbubble generator; 5. slurry outlet; Figure 2 This is a graph showing the particle size of the solid phase product obtained at different mineralization reaction times in Example 1; Figure 3 This is a graph showing the particle size results of the solid phase product obtained at different mineralization reaction times in Comparative Example 1. DETAILED DESCRIPTION

[0021] The structure of the device for utilizing solid waste to mineralize CO2 in flue gas in the present invention is as follows: Figure 1 As shown, the device includes a mineralization reactor 1, and the volume of the mineralization reactor 1 is 200×200×200mm; a nozzle 2 for spraying solid waste slurry is arranged on the top of the mineralization reactor 1, and a microbubble generator 4 for passing flue gas into the mineralization reactor 1 in the form of microbubbles is arranged at the bottom of the mineralization reactor 1; in order to improve the uniformity of flue gas distribution and enhance the mass transfer effect and mineralization efficiency, the nozzle 2 and the microbubble generator 4 are not less than three, and they are evenly distributed on the central axis of the mineralization reactor; a baffle 3 is arranged on the side wall of the mineralization reactor 1; the length of the baffle 3 is equivalent to the width of the side wall of the mineralization reactor; the width of the baffle 3 is 1 / 10~1 / 8 of the length of the mineralization reactor, and the baffle 3 is located at 0.7~0.8 times the height of the mineralization reactor 1; in order to guide the fluid inside the mineralization reactor 1 to have a suitable flow speed and direction, so that the solid waste slurry and flue gas are more evenly distributed, thereby improving the mixing effect, the baffle 3 is arranged on the side wall of the mineralization reactor 1 at an angle downward. A slurry outlet 5 is provided at the lower end of the side wall of the mineralization reactor 1; a temperature sensor is provided on the inner wall of the mineralization reactor 1, and the temperature regulating device comprises a heat source, a cold source, an interlayer provided on the surface of the mineralization reactor 1, a coil provided on the inner wall of the mineralization reactor 1 and a processor, and a heat source outlet and a heat source inlet are provided on the interlayer; the heat source outlet and the heat source inlet are respectively connected to the heat source through an electric control valve, the outlet and the inlet of the coil are respectively connected to each cold source through an electric control valve, the processor is connected to each electric control valve and controls its on and off, and during the regulating process, according to the severity of the heating rate in the mineralization reactor 1, a cold source of a certain temperature is selected to be connected to the coil to cool the mineralization reactor 1.

[0022] The following is a further detailed description of the method for utilizing CO2 in flue gas from phosphate tailings in the above-mentioned device through examples.

[0023] Example 1 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 800°C for 2h, then sieving the calcined phosphate tailings powder to obtain a phosphate tailings powder with a particle size of less than 100μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 1000g of water to obtain a phosphate tailings slurry, and adding ammonia water to adjust the pH of the phosphate tailings slurry to make the pH of the phosphate tailings slurry = 10; S2: The phosphate tailings slurry is introduced into the mineralization reactor 1 through the nozzle 2 in the form of a jet, and the jet speed is 5m / s. At the same time, the flue gas containing 50wt% CO2 is introduced into the mineralization reactor 1 in the form of microbubbles through the microbubble generator 4, and the speed at which the microbubbles enter the reactor is 0.2m / s. The diameter of the microbubbles is less than 50μm. The temperature in the mineralization reactor 1 is controlled to be 40°C, and the phosphate tailings slurry and the flue gas are kept warm for reaction for 20min; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0024] Example 2 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 700°C for 1h, then sieving the calcined phosphate tailings powder to obtain a phosphate tailings powder with a particle size of less than 100μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 2000g of water to obtain a phosphate tailings slurry, and adding ammonia water to adjust the pH of the phosphate tailings slurry to make the pH of the phosphate tailings slurry = 10; S2: The phosphate tailings slurry is introduced into the mineralization reactor 1 through the nozzle 2 in the form of a jet, and the jet speed is 0.5m / s. At the same time, the flue gas containing 50wt% CO2 is introduced into the mineralization reactor 1 in the form of microbubbles through the microbubble generator 4, and the speed at which the microbubbles enter the reactor is 0.5m / s. The diameter of the microbubbles is less than 50μm. The temperature in the mineralization reactor 1 is controlled to be 50°C, and the phosphate tailings slurry and the flue gas are kept warm for reaction for 20min; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0025] Example 3 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 900°C for 4h, then sieving the calcined phosphate tailings powder to obtain phosphate tailings powder with a particle size of less than 100μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 1500g of water to obtain phosphate tailings slurry, and testing the pH of the phosphate tailings slurry with a pH meter to find that the pH is 11; S2: The phosphate tailings slurry is introduced into the mineralization reactor 1 through the nozzle 2 in the form of a jet, and the jet speed is 3m / s. At the same time, the flue gas containing 5wt% CO2 is introduced into the mineralization reactor 1 in the form of microbubbles through the microbubble generator 4, and the speed at which the microbubbles enter the reactor is 0.4m / s. The diameter of the microbubbles is less than 50μm. The temperature in the mineralization reactor 1 is controlled to be 20°C, and the phosphate tailings slurry and the flue gas are kept warm for 20min. S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0026] Example 4 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 800°C for 3h, then sieving the calcined phosphate tailings powder to obtain a phosphate tailings powder with a particle size of less than 100μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 1000g of water to obtain a phosphate tailings slurry, and adding ammonia water to adjust the pH of the phosphate tailings slurry to make the pH of the phosphate tailings slurry = 10; S2: The phosphate tailings slurry is introduced into the mineralization reactor 1 through the nozzle 2 in the form of a jet, and the jet speed is 1m / s. At the same time, the flue gas containing 50wt% CO2 is introduced into the mineralization reactor 1 in the form of microbubbles through the microbubble generator 4, and the speed at which the microbubbles enter the reactor is 0.2m / s. The diameter of the microbubbles is less than 50μm. The temperature in the mineralization reactor 1 is controlled to be 40°C, and the phosphate tailings slurry and the flue gas are kept warm for reaction for 15min; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0027] Example 5 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 800°C for 2h, then sieving the calcined phosphate tailings powder to obtain a phosphate tailings powder with a particle size of less than 200μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 1000g of water to obtain a phosphate tailings slurry, and adding ammonia water to adjust the pH of the phosphate tailings slurry to make the pH of the phosphate tailings slurry = 10; S2: The phosphate tailings slurry is introduced into the mineralization reactor 1 through the nozzle 2 in the form of a jet, and the jet speed is 4m / s. At the same time, the flue gas containing 5wt% CO2 is introduced into the mineralization reactor 1 in the form of microbubbles through the microbubble generator 4, and the speed at which the microbubbles enter the reactor is 0.2m / s. The diameter of the microbubbles is less than 50μm. The temperature in the mineralization reactor 1 is controlled to be 40°C, and the phosphate tailings slurry and the flue gas are kept warm for reaction for 10min. S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0028] Example 6 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 900°C for 3h, then sieving the calcined phosphate tailings powder to obtain a phosphate tailings powder with a particle size of less than 300μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 1500g of water to obtain a phosphate tailings slurry, and adding ammonia water to adjust the pH of the phosphate tailings slurry to make the pH of the phosphate tailings slurry = 10; S2: The phosphate tailings slurry is introduced into the mineralization reactor 1 through the nozzle 2 in the form of a jet, and the jet speed is 5m / s. At the same time, the flue gas containing 100wt% CO2 is introduced into the mineralization reactor 1 in the form of microbubbles through the microbubble generator 4, and the speed at which the microbubbles enter the reactor is 0.2m / s. The diameter of the microbubbles is less than 50μm. The temperature in the mineralization reactor 1 is controlled to be 40°C, and the phosphate tailings slurry and the flue gas are kept warm for reaction for 10min; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0029] Comparative Example 1 A method for mineralizing CO2 in flue gas from phosphate tailings, the method comprising the following steps: S1: calcining the phosphate tailings at 800°C for 2h, then sieving the calcined phosphate tailings powder to obtain a phosphate tailings powder with a particle size of less than 100μm, taking 100g of the sieved phosphate tailings powder and mixing it evenly with 1000g of water to obtain a phosphate tailings slurry, and adding ammonia water to adjust the pH of the phosphate tailings slurry to make the pH of the phosphate tailings slurry = 10; S2: Use a common nozzle to spray the phosphate tailings slurry into the mineralization reactor 1, the jet speed is 5m / s, and at the same time, the flue gas containing 50wt% CO2 is introduced into the mineralization reactor 1 in the form of bubbles through a bubbling device, the bubble diameter is 1.0~5.0mm, and the speed of the bubbles entering the reactor is 0.2m / s. The temperature in the mineralization reactor 1 is controlled to 40℃, and the phosphate tailings slurry and the flue gas are kept warm for 20min; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet 5, the reaction liquid is filtered, and the solid product is dried at 60° C. for 12 hours to obtain carbonate.

[0030] The mineralization effects of the phosphate tailings for CO2 mineralization in Examples 1 to 6 are consistent. Taking Example 1 as an example, the performance of the solid product carbonate is explained and the effect of the mineralization method is verified.

[0031] Test example 1. Particle size test After 5 min, 10 min, 15 min and 20 min of mineralization reaction in Example 1 and Comparative Example 1, the solid product carbonate was sampled, the sample was filtered and dried at 60° C. for 12 h, and then the particle size of the sample was tested using a laser particle size analyzer. The test results are as follows: Figure 2 and Figure 3As shown in the figure, during the mineralization reaction from 5min to 10min in the embodiment, the particle size of the solid phase product first becomes smaller and then slowly increases. The reason is that the carbonation reaction is not perfect at 5min, and a part of calcium sulfate exists, showing a larger particle size. After the reaction is carried out for 10min, the particle size of the carbonate product D 50 The carbonate generated by the reaction began to agglomerate and the particle size became larger. At 20 min, D 50 is 2.586 μm, at which time the carbonation efficiency of the reaction is close to saturation; while in Comparative Example 1, the D 50 It is 7.568 μm. It can be seen that the particle size of the product obtained from the mineralization reaction in the embodiment is greatly reduced. This is because CO2 and phosphate tailings slurry are introduced into the mineralization reactor by two intensification methods, namely microbubbles and slurry jets, which enhance the turbulence of the slurry, increase the gas-liquid mass transfer area and interface renewal rate between the microbubbles and the phosphate tailings slurry, and generate small-size and high-quality carbonate products.

[0032] 2. Mineralization rate η test After 5 min, 10 min, 15 min and 20 min of mineralization reaction in Example 1 and Comparative Example 1, the reaction solution was sampled, the sample was filtered and dried at 60 ° C for 12 h, the mass of the solid phase product sample after drying was weighed using an electronic balance, and the loss of the solid phase product sample was determined by thermogravimetric analysis between 300 and 800 ° C; the mineralization rate η The calculation formula is as follows:

[0033] in, M is the mass of the solid product sample after the reaction; W 300~800℃ is the loss amount between 300 and 800 °C during the thermogravimetric analysis of the solid phase product sample. M CO2 is the molar mass of CO2, n ( Ca + Mg ) is the total molar amount of calcium and magnesium in the solid phase product. The mineralization rate results in Example 1 and Comparative Example 1 are shown in Table 1. It can be seen that the reaction rate of Comparative Example 1 in the first 10 minutes is only 1 / 4 of that in Example 1. This is because compared with ordinary bubbling gas diffusion, CO2 and phosphate tailings slurry are introduced into the mineralization reactor by two enhanced methods of microbubbles and slurry jets in the embodiments of the present invention. The microbubbles have a longer residence time in the slurry, which significantly improves the reaction efficiency of the phosphate tailings slurry absorbing-mineralizing CO2.

[0034] Table 1 Mineralization rate of phosphate tailings in different time examples and comparative examples

[0035] Although the specific implementation of the present invention is described in detail in conjunction with the embodiments, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A device for utilizing CO2 in solid waste mineralization flue gas, characterized in that: The invention comprises a mineralization reactor (1), wherein the top of the mineralization reactor (1) is provided with a nozzle (2) for spraying solid waste slurry, the bottom is provided with a microbubble generator (4) for passing flue gas into the mineralization reactor (1) in the form of microbubbles, and the side wall is provided with a baffle (3); the baffle (3) is located at 0.7 to 0.8 times the height of the mineralization reactor (1); the lower end of the side wall of the mineralization reactor (1) is provided with a slurry outlet (5); the inner wall of the mineralization reactor (1) is provided with a temperature sensor, and the outer wall is provided with a temperature regulation system.

2. The device for utilizing CO2 in solid waste mineralization flue gas according to claim 1, characterized in that: The number of the nozzles (2) and the number of the microbubble generators (4) are no less than three, and they are distributed at equal intervals on the central axis of the mineralization reactor (1).

3. The device for utilizing CO2 in solid waste mineralization flue gas according to claim 1, characterized in that: The length of the baffle (3) is equivalent to the width of the side wall of the mineralization reactor (1); the width of the baffle (3) is 1 / 10 to 1 / 8 of the length of the mineralization reactor (1).

4. The device for utilizing CO2 in solid waste mineralization flue gas according to claim 1 or 3, characterized in that: The baffle (3) is arranged on the side wall of the mineralization reactor (1) in a downwardly inclined manner.

5. The device for utilizing CO2 in solid waste mineralization flue gas according to claim 1, characterized in that: The temperature regulating system comprises a cold source and a hot source for regulating the temperature of the mineralization reactor (1).

6. A method for utilizing solid waste to mineralize CO2 in flue gas, characterized in that: The method is carried out using the device according to any one of claims 1 to 5, comprising the following steps: S1: mixing solid waste powder and water to obtain slurry; S2: the slurry is introduced into the mineralization reactor (1) through the nozzle (2) in the form of a jet, and the flue gas containing CO2 is introduced into the mineralization reactor (1) in the form of microbubbles through the microbubble generator (4), the temperature in the mineralization reactor (1) is controlled to be 20-50° C., and the reaction is kept at this temperature for 10-20 minutes; S3: After the mineralization reaction is completed, the reaction liquid is discharged from the slurry outlet (5), filtered and dried to obtain carbonate.

7. The method for utilizing CO2 in solid waste mineralization flue gas according to claim 6, characterized in that: The solid waste is calcined phosphorus tailings, the calcination temperature is 700-900° C., and the calcination time is 1-4 hours.

8. The method for utilizing CO2 in solid waste mineralization flue gas according to claim 7, characterized in that: The particle size of the solid waste powder is less than 300 μm; the mass ratio of the solid waste powder to water is 1:10-20.

9. The method for utilizing CO2 in solid waste mineralization flue gas according to claim 8, characterized in that: The pH of the slurry is ≥10.

10. The method for utilizing CO2 in solid waste mineralization flue gas according to claim 9, characterized in that: In step S2, the jet velocity is 0.5-5 m / s; the diameter of the microbubbles is less than 50 μm; the speed at which the microbubbles enter the reactor is 0.2-0.5 m / s; and the concentration of CO2 in the flue gas is 5-100 wt%.

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