Microbial mineralization high-strength carbonized aerated concrete and preparation method thereof

Abstract

The present application provides a kind of microbial mineralization high-strength carbonized aerated concrete and its preparation method, microbial mineralization high-strength carbonized aerated concrete includes the following weight parts of each component: carbonized cementitious material 100 parts, water 10-25 parts, 3-6 parts of aerobic microbial bacteria powder with mineralization deposition function, 3-7 parts of hydrogen peroxide, 0.2-0.3 parts of water reducing agent, 1-10 parts of nutrient solution;The concrete slurry prepared by the above components is poured into shape after static standing maintenance, and CO2 carbonization maintenance is carried out to obtain the microbial mineralization high-strength carbonized aerated concrete.The present application combines microbial mineralization pre-carbonization and kiln tail gas carbonization, solves the problem that aerated concrete carbonization maintenance condition is high and internal carbonization is difficult to complete, and is economic and environmental protection, and the prepared aerated concrete is carbonized uniformly, and has good thermal insulation performance and shrinkage performance.

Description

Technical Field

[0001] This invention relates to the field of aerated concrete technology, specifically to a microbial mineralized high-strength carbonized aerated concrete and its preparation method. Background Technology

[0002] With the rapid development of modern industry, people's demand for building materials will continue to grow, and the production of building materials will not decrease significantly in the future. As a result, the problems of CO2 emission reduction and air pollution need to be addressed urgently.

[0003] Currently, carbon dioxide capture, utilization, and storage (CCUS) technology is an important technical route for reducing carbon dioxide emissions and achieving carbon neutrality. Meanwhile, aerated concrete (AAC), as a new type of energy-saving building wall material, has been widely used. It possesses excellent properties such as lightweight, thermal insulation, earthquake resistance, and fire resistance. Its rich internal porosity (40-80%) facilitates CO2 diffusion and reaction, resulting in a high carbon sequestration capacity. During the carbonization curing process, AAC can fix some carbon dioxide, making its production more energy-efficient and environmentally friendly, and is an important way to reduce environmental pollution. However, it also suffers from problems such as low carbonization degree within the AAC block, high requirements for carbonization curing conditions (long carbonization time, high carbonization concentration, etc.), slow hardening of the block, poor volume stability leading to long static curing time, and poor performance. Summary of the Invention

[0004] To address the problems existing in the background technology, the present invention provides a microbial mineralized high-strength carbonized aerated concrete and its preparation method, which can significantly shorten the preparation cycle of carbonized aerated concrete, and the prepared aerated concrete has uniform carbonization, good thermal insulation performance and shrinkage performance.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] In a first aspect, the present invention provides a microbial mineralized high-strength carbonized aerated concrete, comprising the following components in parts by weight: 100 parts of carbonized cementitious material, 10-25 parts of water, 3-6 parts of aerobic microbial powder with mineralization deposition function, 3-7 parts of hydrogen peroxide, 0.2-0.3 parts of water-reducing agent, and 1-10 parts of nutrient solution.

[0007] The concrete slurry prepared from the above components is poured, shaped, and then subjected to CO2 carbonization curing to obtain the microbial mineralized high-strength carbonized aerated concrete.

[0008] According to the above scheme, the carbonized cementitious material includes 70-85 parts of air-hardening material and 15-30 parts of hydraulic material.

[0009] According to the above scheme, the air-hardening material is one or two of magnesium slag and steel slag, and the hydraulic material is one or more of silicate cement, aluminate cement and sulfoaluminate cement.

[0010] According to the above scheme, the specific surface area of ​​the hydraulic material is 300-400 m². 2 / kg.

[0011] According to the above scheme, the air-hardening material is a mixture of magnesium slag and steel slag, with magnesium slag accounting for 60% to 80% of the air-hardening material.

[0012] According to the above scheme, the total content of the carbonized active mineral components CS, C3S2, C3S, and C2S in the air-hardening material is greater than 80wt%.

[0013] According to the above scheme, the specific surface area of ​​the air-hardening material is 300-400 m². 2 / kg.

[0014] According to the above scheme, the aerobic microorganism is one or more of Bacillus coliformis, Bacillus pseudostrongylus, and Bacillus subtilis.

[0015] According to the above scheme, the mass concentration of the hydrogen peroxide is 27.5% to 35%.

[0016] According to the above scheme, the water-reducing agent is a polycarboxylate water-reducing agent.

[0017] According to the above scheme, the nutrient solution is a nutrient solution that can provide organic nutrients for aerobic microorganisms.

[0018] The nutrient solution may be selected from, but is not limited to, one or more of the following: calcium lactate solution, calcium propionate solution, calcium butyrate solution, tartaric acid solution, citric acid solution, with a mass concentration of 50-70%.

[0019] The aforementioned aerobic microbial powder can be commercially available or homemade. In some specific embodiments of the present invention, the preparation method is as follows: an aerobic microbial strain with mineralization deposition function is inoculated into a sterilized liquid culture medium and placed in a shaker. It is then cultured at a constant temperature of 20–30°C and 50–200 r / min for 12–60 h to obtain a bacterial solution containing aerobic microorganisms. After centrifugation at 2000–5000 r / min for 10–20 min at 20–30°C, the supernatant is removed, and deionized water is added to prepare a bacterial cell concentration of 10. 7 ~10 9 The concentrated bacterial solution with a concentration of cells / mL is then used to prepare bacterial powder using a spray dryer.

[0020] Secondly, the present invention provides a method for preparing the above-mentioned microbially mineralized high-strength carbonized aerated concrete, comprising the following steps:

[0021] S1. Preparation of slurry solution: Weigh each component according to the mass fractions, and mix the carbonized cementitious material, water, aerobic microbial powder with mineralization deposition function and water-reducing agent evenly to prepare slurry solution;

[0022] S2. Preparation of finished slurry: Hydrogen peroxide and nutrient solution are added to the slurry solution and stirred evenly to obtain the finished slurry;

[0023] S3. Casting and Curing: Pour the finished slurry into the mold to form the shape, and place the mold in the curing chamber for curing.

[0024] S4.CO2 carbonization curing: After the green body is demolded and cut, it is placed in a carbonization kettle and kiln tail flue gas is introduced for carbonization curing to obtain the microbial mineralized high-strength carbonized aerated concrete.

[0025] According to the above scheme, the stirring time in step S1 is 3 to 5 minutes, and the stirring rate is 300 to 600 r / min.

[0026] According to the above scheme, the stirring time in step S2 is 1 to 2 minutes, and the stirring rate is 450 to 750 r / min.

[0027] According to the above plan, the temperature for static curing in step S3 is 30-50℃, and the time is 2-3 hours.

[0028] The temperature during static curing can be maintained using the residual heat from the kiln tail flue gas duct.

[0029] According to the above scheme, the carbonization curing temperature in step S4 is 50-70℃, the time is 4-8 hours, the CO2 concentration in the kiln tail flue gas is not less than 15%, the pressure is 0.1-0.3 MPa, and the relative humidity is 50%-70%. Preferably, the CO2 concentration in the kiln tail flue gas is 25%-35%.

[0030] Hydrogen peroxide, used as a foaming agent in this aerated concrete, decomposes during the static curing stage to produce a large amount of oxygen, thus providing an oxygen-rich environment. In this oxygen-rich environment, aerobic microorganisms with mineralization and deposition functions can decompose organic nutrients in the nutrient solution through aerobic respiration to produce CO2, accelerating the dissolution of phase ions in the carbonized cementitious material and forming calcium carbonate precipitate with the dissolved calcium ions. Through the mineralization of aerobic microorganisms, the interior of the aerated block is pre-carbonized. Combined with a carbon dioxide curing system, microbial mineralized high-strength carbonized aerated concrete is obtained.

[0031] The beneficial effects of this invention are:

[0032] 1) This invention combines microbial mineralization pre-carbonization and kiln tail flue gas carbonization for secondary carbonization curing, improving the carbonization efficiency and degree of aerated concrete. Microbial mineralization achieves pre-carbonization curing inside the green body, forming stable carbonate mineralization products within the aerated block during the pre-carbonization process, increasing the green body strength. Simultaneously, it accelerates the dissolution and transformation of free oxide components that cause expansion in the carbonized cementitious materials, improving the volume stability of the green body. This solves the problem of high carbonization curing conditions and difficulty in complete internal carbonization of aerated concrete products. Furthermore, combined with the secondary oxidation process of kiln tail flue gas carbonization, the exterior of the green body is further carbonized, resulting in high-performance aerated concrete products.

[0033] 2) The activation effect of microorganisms can accelerate and improve the dissolution of calcium and magnesium phase ions in carbonized cementitious materials, and generate more stable carbonate minerals and active minerals through mineralization, thereby increasing the hardening reaction rate of the green body and shortening the static curing time, which can significantly improve the factory turnover efficiency.

[0034] 3) This invention pre-carbonizes carbonized cementitious materials using microorganisms. The aerobic metabolism of microorganisms does not produce toxic ions that cause secondary pollution to the environment, and it can significantly shorten the subsequent carbonization curing time. It is characterized by high efficiency, simple method, economy and environmental protection. At the same time, it uses kiln tail flue gas for secondary carbonization curing, which reduces curing energy consumption and carbon emissions of the factory. It has wide applicability and has significant environmental and economic benefits. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the production process of microbial mineralization high-strength carbonized aerated concrete according to the present invention. Detailed Implementation

[0036] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0037] It should be noted that, in the description of the embodiments of this application, the term "some specific embodiments" means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same implementation or instance. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0038] This invention provides a microbial mineralized high-strength carbonized aerated concrete, comprising the following components in parts by weight: 100 parts carbonized cementitious material, 10-25 parts water, 3-6 parts aerobic microbial powder with mineralization deposition function, 3-7 parts hydrogen peroxide, 0.2-0.3 parts water-reducing agent, and 1-10 parts nutrient solution.

[0039] The concrete slurry prepared from the above components is poured, shaped, and then subjected to CO2 carbonization curing to obtain the microbial mineralized high-strength carbonized aerated concrete.

[0040] In some specific embodiments, the carbonized cementitious material includes 70-85 parts of air-hardening material and 15-30 parts of hydraulic material.

[0041] According to the above scheme, the air-hardening material is one or two of magnesium slag and steel slag, and the hydraulic material is one or more of silicate cement, aluminate cement and sulfoaluminate cement.

[0042] In some specific embodiments, the specific surface area of ​​the hydraulic material is 300–400 m². 2 / kg.

[0043] In some specific embodiments, the air-hardening material is a mixture of magnesium slag and steel slag, with magnesium slag accounting for 60% to 80% of the air-hardening material.

[0044] In some specific embodiments, the total content of the carbonized active mineral components CS, C3S2, C3S, and C2S in the air-hardening material is greater than 80 wt%.

[0045] In some specific embodiments, the specific surface area of ​​the air-hardening material is 300–400 m². 2 / kg

[0046] In some specific embodiments, the aerobic microorganism is one or more of Bacillus coliformis, Bacillus pseudostrongylus, and Bacillus subtilis.

[0047] Specifically, the mass concentration of the hydrogen peroxide is 27.5% to 35%.

[0048] In some specific embodiments, the water-reducing agent is a polycarboxylate water-reducing agent.

[0049] Specifically, the nutrient solution is a nutrient solution that can provide organic nutrients for aerobic microorganisms.

[0050] The nutrient solution may be selected from, but is not limited to, one or more of the following: calcium lactate solution, calcium propionate solution, calcium butyrate solution, tartaric acid solution, citric acid solution, etc., with a mass concentration of 50-70%.

[0051] The aforementioned aerobic microbial powder can be commercially available or homemade. In some specific embodiments of the present invention, the preparation method is as follows: aerobic microbial powder with mineralization deposition function is inoculated into sterilized liquid culture medium and placed in a shaker for constant temperature incubation at 20-30℃ and 50-200 r / min for 12-60 h to obtain a bacterial solution containing aerobic microorganisms. After centrifugation at 2000-5000 r / min for 10-20 min at 20-30℃, the supernatant is removed, and deionized water is added to prepare a bacterial cell concentration of 10. 7 ~10 9 The concentrated bacterial solution with a concentration of cells / mL is then used to prepare bacterial powder using a spray dryer.

[0052] Secondly, such as Figure 1 As shown, the present invention provides a method for preparing the above-mentioned microbially mineralized high-strength carbonized aerated concrete, comprising the following steps:

[0053] S1. Preparation of slurry solution: Weigh each component according to the mass fractions, and mix the carbonized cementitious material, water, aerobic microbial powder with mineralization deposition function and water-reducing agent evenly to prepare slurry solution;

[0054] S2. Preparation of finished slurry: Hydrogen peroxide and nutrient solution are added to the slurry solution and stirred evenly to obtain the finished slurry;

[0055] S3. Casting and Curing: Pour the finished slurry into the mold to form the shape, and place the mold in the curing chamber for curing.

[0056] S4. Carbonation curing: After the green body is demolded and cut, it is placed in a carbonation kettle and kiln tail flue gas is introduced for carbonation curing to obtain the microbial mineralized high-strength carbonized aerated concrete.

[0057] In step S4, CO2 from the kiln tail flue gas is used for carbonization curing.

[0058] In some specific embodiments, the stirring time in step S1 is 3 to 5 minutes, and the stirring rate is 300 to 600 r / min.

[0059] In some specific embodiments, the stirring time in step S2 is 1 to 2 minutes, and the stirring rate is 450 to 750 r / min.

[0060] In some specific embodiments, the temperature for static curing in step S3 is 30-50°C, and the time is 2-3 hours.

[0061] In some specific embodiments, the carbonization curing temperature in step S4 is 50–70°C, the time is 4–8 hours, the CO2 concentration in the kiln tail flue gas is not less than 15%, the pressure is 0.1–0.3 MPa, and the relative humidity is 50%–70%. Preferably, the CO2 concentration in the kiln tail flue gas is 25%–35%.

[0062] Hydrogen peroxide, used as a foaming agent in this aerated concrete, decomposes during the static curing stage to produce a large amount of oxygen, thus providing an oxygen-rich environment. In this oxygen-rich environment, aerobic microorganisms with mineralization and deposition functions can decompose organic nutrients in the nutrient solution through aerobic respiration to produce CO2, accelerating the dissolution of phase ions in the carbonized cementitious material and forming calcium carbonate precipitate with the dissolved calcium ions. Through the mineralization of aerobic microorganisms, the interior of the aerated block is pre-carbonized. Combined with a carbon dioxide curing system, microbial mineralized high-strength carbonized aerated concrete is obtained.

[0063] Based on the above embodiments, the present invention provides the following specific examples to further illustrate the invention. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following examples, unless otherwise specified, are generally performed according to the manufacturer's recommended conditions. Unless otherwise stated, percentages and parts are calculated by mass.

[0064] In the following examples, the P.O42.5 silicate cement, sulfoaluminate cement, magnesium slag, and water-reducing agent used were provided by Huaxin Cement Co., Ltd., wherein the specific surface area of ​​the P.O42.5 silicate cement and sulfoaluminate cement is 350 m². 2 / kg; The main mineral composition and their mass percentage in magnesium slag are: C3S 10%, β-C2S 34%, C3S2 11%, CS 38%, SiO2 4.9%, MgO 2%, and the specific surface area after ball milling is 330m². 2 / kg; the water-reducing agent has a water-reducing efficiency of 30%; the hydrogen peroxide used is provided by Wuhan Luhu Chemical Co., Ltd., with a mass concentration of 27.5%; the steel slag used is a by-product generated during the ironmaking process of steel plants, and its main mineral composition and mass percentage include: C2S 26.2%, C3S 28.6%, CS 32.6%, C3S 10.8%, quartz 9%, limonite dolomite 12.7%, and a specific surface area of ​​320m² after ball milling. 2 / kg; the nutrient solution used was a laboratory-prepared calcium lactate solution with a concentration of 60%; the microbial powder used (Bacillus coliformis and Bacillus pseudostrongylus) was prepared after laboratory culture.

[0065] The preparation method of microbial inoculum is as follows: *Bacillus coli* is inoculated into sterile liquid culture medium containing 10g peptone, 3g beef extract, 5g NaCl, and 15g agar per liter of medium. The pH of the medium is adjusted to 7 with sodium hydroxide, and the medium is placed in a shaker and incubated at 30℃ and 150r / min for 48h to obtain the microbial inoculum. After centrifugation at 4000r / min for 15min at 30℃, the supernatant is removed, and deionized water is added to prepare a bacterial concentration of 10. 8 The bacterial solution is concentrated at cells / mL, and then the bacterial solution is prepared into powder using an LPG-50 spray dryer to obtain microbial powder.

[0066] Example 1

[0067] The raw materials were weighed according to the following proportions by weight: 100 parts carbonized cementitious material, 25 parts water, 4 parts microbial powder, 0.3 parts water-reducing agent, 15 parts hydrogen peroxide (mass concentration 27.5%), and 6 parts nutrient solution; wherein the mass ratio of air-hardening material to hydraulic material in the carbonized cementitious material was 75:25, and the raw materials and their proportions in the air-hardening material were: 70wt% magnesium slag, 30wt% steel slag, and 85% carbonized active mineral components; all hydraulic materials were selected from P.O42.5 silicate cement.

[0068] The weighed carbonized cementitious material, microbial powder, water-reducing agent and water were stirred at a speed of 450 r / min for 4 min to obtain a slurry solution; then hydrogen peroxide and nutrient solution were added to the slurry solution and stirred at a speed of 600 r / min for 1 min to obtain the finished slurry.

[0069] The finished slurry is poured into the mold frame and cured statically at 40℃ for 2 hours before demolding and cutting. After cutting, the green body is placed in the autoclave for carbonization curing with kiln tail flue gas (wherein, the CO2 concentration of kiln tail flue gas is controlled at 30%, the pressure inside the autoclave is 0.2MPa, the temperature is 60℃, and the relative humidity is 65%), and the carbonization time is 4h (#1), 6h (#2), and 8h (#3).

[0070] The performance of the carbonized aerated concrete in this embodiment was tested in accordance with the standard GB / T11969-2008. The specific test results are shown in Table 1.

[0071] Table 1. Performance test results of the aerated concrete obtained in Example 1

[0072]

[0073] Example 2

[0074] A microbial mineralized high-strength carbonized aerated concrete, the preparation method of which differs from Example 1, is as follows: the microbial powder used is a mixture of Bacillus coccidioides and Bacillus pseudostrongylus (Bacillus coccidioides: Bacillus pseudostrongylus = 40:60), the hydraulic material is a composite of P.O42.5 silicate cement and sulfoaluminate cement, P.O42.5 silicate cement: sulfoaluminate cement = 75:25, and the carbonation time is 8 hours; the specific performance test results are shown in Table 2.

[0075] Table 2. Performance test results of the aerated concrete obtained in Example 2

[0076]

[0077] Example 3

[0078] A microbial mineralized high-strength carbonized aerated concrete, the preparation method of which differs from Example 1, is as follows: 5 parts by weight of microbial powder are used; the mass ratio of air-hardening material to hydraulic material in the carbonized cementitious material is 85:15; the raw materials and their proportions in the air-hardening material are: 80wt% magnesium slag, 20wt% steel slag; the carbonization active mineral component in the air-hardening material is 93%; and the carbonization time is 8 hours. Specific performance test results are shown in Table 3.

[0079] Table 3. Performance test results of the aerated concrete obtained in Example 3

[0080]

[0081] Comparative Example 1

[0082] This comparison provides a carbonized aerated concrete, the preparation method of which differs from that of Example 1 in that: no microbial powder is added, the static curing time of the prepared green body is 10h, and the carbonization time during the carbonization curing process is 4h, 6h, and 8h respectively; the specific performance test results are shown in Table 4.

[0083] Table 4 shows the performance test results of the carbonized aerated concrete obtained in Comparative Example 1.

[0084]

[0085] Comparative Example 2

[0086] A microbial mineralized high-strength carbonized aerated concrete is prepared in a manner that differs from that in Example 1 in that: the microbial powder is 2 parts (ratio #9) and 10 parts (ratio #10), the mixing and curing regimes are kept consistent, and the carbonization time is 8 hours; the specific performance test results are shown in Table 5.

[0087] Table 5. Performance test results of the aerated concrete obtained in Comparative Example 2

[0088]

[0089] Comparative Example 3

[0090] A microbially mineralized high-strength carbonized aerated concrete, the preparation method of which differs from that of Example 1, is as follows: the carbonization active mineral component in the air-hardening material is 60%, and the carbonization time is 8 hours; specific performance test results are shown in Table 6.

[0091] Table 6 shows the performance test results of the aerated concrete obtained in Comparative Example 3.

[0092]

[0093] By selecting specific aerobic microbial strains and combining them with appropriate proportions of carbonization-active mineral components, microbially mineralized high-strength carbonized aerated concrete with optimal performance can be achieved. Based on the above examples and comparative experimental data, the type and dosage of aerobic microorganisms, as well as the proportion of carbonization-active mineral components, are two key technical aspects of microbially mineralized high-strength carbonized aerated concrete. These two aspects complement each other. Composite aerobic microbial powder can further accelerate the dissolution of phase ions, improve the utilization rate of calcium and magnesium minerals, and achieve a deeper degree of carbonization, further improving the compressive strength and splitting tensile strength of the carbonized aerated blocks, as well as improving thermal conductivity and drying shrinkage performance. Excessive microbial powder will destroy the already generated hydration products, disrupt the internal volume stability of the aerated blocks, and significantly reduce the compressive strength and splitting tensile strength of the carbonized aerated blocks, while also worsening thermal conductivity, bulk density, and drying shrinkage performance. Insufficient microbial powder will result in a low degree of carbonization, a small amount of carbonization products, reduced compressive strength and splitting tensile strength of the carbonized aerated blocks, and worsening thermal conductivity, bulk density, and drying shrinkage performance.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microbially mineralized high-strength carbonized aerated concrete, characterized in that, The product comprises the following components in parts by weight: 100 parts carbonized cementitious material, 10-25 parts water, 3-6 parts aerobic microbial powder with mineralization and deposition functions, 3-7 parts hydrogen peroxide, 0.2-0.3 parts water-reducing agent, and 1-10 parts nutrient solution; wherein the carbonized cementitious material comprises 70-85 parts air-hardening material and 15-30 parts hydraulic material, and the total content of the carbonized active mineral components CS, C3S2, C3S, and C2S in the air-hardening material is greater than 80 wt%. The concrete slurry prepared from the above components is poured, shaped, and then subjected to CO2 carbonization curing to obtain the microbial mineralized high-strength carbonized aerated concrete.

2. The microbial mineralized high-strength carbonized aerated concrete according to claim 1, characterized in that, The air-hardening material is one or both of magnesium slag and steel slag, and the hydraulic material is one or more of silicate cement, aluminate cement and sulfoaluminate cement.

3. The microbial mineralized high-strength carbonized aerated concrete according to claim 2, characterized in that, The air-hardening material is a mixture of magnesium slag and steel slag, with magnesium slag accounting for 60% to 80% of the air-hardening material.

4. The microbial mineralized high-strength carbonized aerated concrete according to claim 1, characterized in that, The aerobic microorganism is one or more of Bacillus coli, Bacillus pseudostrongylus, and Bacillus subtilis.

5. The microbial mineralized high-strength carbonized aerated concrete according to claim 1, characterized in that, The nutrient solution is a nutrient solution that can provide organic nutrients for aerobic microorganisms.

6. The method for preparing microbially mineralized high-strength carbonized aerated concrete according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of slurry solution: Weigh each component according to the mass fractions, and mix the carbonized cementitious material, water, aerobic microbial powder with mineralization deposition function and water-reducing agent evenly to prepare slurry solution; S2. Preparation of finished slurry: Hydrogen peroxide and nutrient solution are added to the slurry solution and stirred evenly to obtain the finished slurry; S3. Casting and Curing: Pour the finished slurry into the mold to form the shape, and place the mold in the curing chamber for curing. S4. Carbonation curing: After the green body is demolded and cut, it is placed in a carbonation kettle and kiln tail flue gas is introduced for carbonation curing to obtain the microbial mineralized high-strength carbonized aerated concrete.

7. The preparation method according to claim 6, characterized in that, In step S3, the static curing temperature is 30~50℃ and the time is 2~3 hours.

8. The preparation method according to claim 6, characterized in that, In step S4, the carbonization curing temperature is 50~70℃, the time is 4~8h, the CO2 concentration in the kiln tail flue gas is not less than 15%, and the pressure is 0.1~0.3MPa.

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