Autoclaved aerated concrete prepared using bottom slag and a method of preparing the same

Abstract

The application relates to the field of concrete, and particularly discloses a steam pressure aerated concrete prepared from furnace bottom slag and a preparation method thereof. The steam pressure aerated concrete prepared from the furnace bottom slag comprises granulated blast furnace slag, carbon slag, quartz sand, Portland cement, lime, desulfurization gypsum, aluminum powder, reinforcing fiber and foam stabilizer. The preparation method is as follows: the granulated blast furnace slag, the carbon slag, the quartz sand and water are mixed to prepare a slurry, the lime and the desulfurization gypsum are added to the slurry and stirred, the reinforcing fiber is added to the slurry, the Portland cement is added after the slurry is uniformly stirred, the foam stabilizer is added, the aluminum powder is added after the slurry is thickened and kept, and the slurry is poured into a mold after being stirred, the concrete in the mold is cured, the mold is demolded, the green body is cut, the green body is high-temperature and high-pressure steam cured, and the steam pressure aerated concrete is prepared. The steam pressure aerated concrete prepared from the furnace bottom slag has the advantages of solving the problem of high water absorption of the steam pressure aerated concrete.

Description

Technical Field

[0001] This application relates to the field of concrete, and more specifically, to an autoclaved aerated concrete prepared using bottom slag and a method thereof. Background Technology

[0002] Autoclaved aerated concrete (AAC), as a lightweight, high-strength building material with excellent thermal insulation properties, has been widely used in the construction industry in recent years. Its emergence has not only greatly promoted the advancement of building technology but also provided strong support for the development of green and energy-efficient buildings.

[0003] Autoclaved aerated concrete (AAC) can be traced back to the mid-20th century. With rapid industrialization, traditional solid bricks and concrete materials, due to their heavy weight and high thermal conductivity, have gradually become unable to meet the demands of modern buildings for energy conservation, environmental protection, and efficient construction. Therefore, the development of new lightweight, high-strength building materials with good thermal insulation properties has become an urgent need in the industry.

[0004] It is against this backdrop that autoclaved aerated concrete (AAC) came into being. Its main raw materials are siliceous and calcareous materials, such as sand, lime, and cement, which are produced through processes including mixing with water, pouring into molds, static curing, cutting, and autoclaving. During autoclaving, a calcium silicate hydration reaction occurs inside the material, generating a large number of tiny air bubbles, giving the concrete its lightweight and porous characteristics.

[0005] Autoclaved aerated concrete (AAC) itself has a certain water absorption capacity, especially when no waterproofing measures are taken, its water absorption rate can be very high. During the preparation process, AAC blocks are prone to problems such as block adhesion and undercooked blocks. When the blocks absorb a large amount of water, it will not only cause the wall to be damp, but may also affect the strength and stability of the blocks, and even cause problems such as wall cracking and deformation. Summary of the Invention

[0006] To address the issue of high water absorption in autoclaved aerated concrete (AAC), this application provides an AAC prepared using bottom slag and its preparation method.

[0007] The autoclaved aerated concrete prepared using bottom slag provided in this application adopts the following technical solution: An autoclaved aerated concrete prepared using bottom slag comprises, by weight, the following components: 60-80 parts granulated blast furnace slag, 30-40 parts carbon slag, 40-60 parts quartz sand, 5-10 parts silicate cement, 1-5 parts lime, 1-2 parts desulfurized gypsum, 0.2-0.4 parts aluminum powder, 0.5-1.5 parts reinforcing fiber, and 0.2-0.5 parts foam stabilizer.

[0008] By adopting the above technical solution and using granulated blast furnace slag and carbon slag as raw materials for autoclaved aerated concrete (AAC) products, the amount of lime in the raw material formula is reduced, thus weakening the water absorption of the raw materials and lowering the product moisture content. This reduces problems such as green body adhesion and undercooked concrete. Through the rational combination of raw material components, this solution can comprehensively improve the performance of concrete, ensuring product quality and construction results.

[0009] Optionally, the granulated blast furnace slag contains Al2O3 > 20% and CaO > 50%.

[0010] By adopting the above technical solutions, the high Al2O3 and CaO content in granulated blast furnace slag is beneficial for improving the compressive strength and durability of concrete. Al2O3 can increase the corrosion resistance and high-temperature resistance of concrete, while CaO also plays an important role in improving the compressive strength and durability of concrete. The application of granulated blast furnace slag helps to reduce the water absorption rate of autoclaved aerated concrete. The high content of Al2O3 and CaO helps to optimize the pore structure of concrete, reduce water penetration, thereby reducing the occurrence of wall dampness problems, and also helps to reduce problems such as green body adhesion and underdevelopment, improving production efficiency and product quality.

[0011] Optionally, the carbon slag has a particle size of 0.1-0.5 mm and an MgO content of 10-15%.

[0012] By adopting the above technical solutions, a carbon slag particle size in the range of 0.1-0.5mm is beneficial to the uniformity and fluidity of concrete, helping to reduce problems such as concrete block adhesion and underdevelopment. A MgO content in the carbon slag in the range of 10-15% can improve the impermeability and durability of concrete, while also helping to regulate the chemical properties of concrete, influencing its hardening rate and early strength development.

[0013] Optionally, the granulated blast furnace slag needs to undergo microencapsulation treatment, and the specific steps of the microencapsulation treatment are as follows: A1. Add 1-5 parts by weight of ethylene glycol, 15-30 parts by weight of polyester polyol and 3-6 parts by weight of diethanolamine into a reaction vessel, dehydrate the mixture, cool it to room temperature, add 10-16 parts by weight of diphenylmethane diisocyanate and 1-3 parts by weight of tertiary amine catalyst, and react at a certain temperature for 2-4 hours to obtain polyurethane prepolymer. A2. When the temperature of the prepolymer drops below 50℃, add 0.5-2 parts of sodium hydroxide and 5-8 parts of diphenylmethane diisocyanate and stir evenly. Add 60-80 parts of blast furnace slag to the prepolymer and stir to disperse. Add 10-20 parts of deionized water and continue stirring to disperse, thereby obtaining a polyurethane prepolymer dispersion containing blast furnace slag. A3. Add 1-5 parts of an organic amine aqueous solution to a polyurethane prepolymer dispersion containing blast furnace slag to carry out a chain extension reaction to obtain a microencapsulated blast furnace slag emulsion with polyurethane as the wall material. Vacuum dry the microencapsulated blast furnace slag emulsion and grind it into microencapsulated granulated blast furnace slag with a particle size of 50-100μm using a grinder.

[0014] By adopting the above technical solutions, the dispersibility of microencapsulated blast furnace slag in concrete is improved, which can enhance the workability of concrete, reduce problems such as billet adhesion and undercooking, and improve production efficiency and product quality. Microencapsulated blast furnace slag is more stable, which helps reduce water penetration into concrete, reduces the occurrence of dampness in walls, improves the compressive strength, corrosion resistance, and durability of concrete, and enhances the overall performance of concrete.

[0015] Optionally, it may also include 5-10 parts by weight of zeolite, wherein the zeolite particle size is 0.5-2 mm.

[0016] By adopting the above technical solution, zeolite has a microporous structure. When zeolite is dispersed in concrete, it can absorb excess water in the concrete and evaporate it slowly, thereby avoiding the problems of cracking and deformation of autoclaved aerated concrete blocks.

[0017] Optionally, the reinforcing fiber includes surface-carbonized straw fiber, which is obtained by heating straw fiber to 500-800°C in an environment with an oxygen content of 0.5-1.5% and then cooling it.

[0018] By adopting the above technical solutions, surface carbonization treatment helps improve the corrosion resistance of fibers, making them more durable. When added to concrete, it can improve the durability of concrete and extend its service life. Surface carbonization treatment forms a carbonized layer on the surface of straw fibers, reducing the water absorption of the fibers themselves, thus reducing the amount of water absorbed by the fibers in concrete. It also has good filling properties, which can improve the micropores of concrete, reduce the connectivity of concrete pores, thereby reducing the rate of water conduction in concrete and reducing the amount of water absorbed by concrete.

[0019] Optionally, the foam stabilizer is selected from fatty alcohol polyoxyethylene ether or fatty alcohol polyoxyethylene ether silane.

[0020] By adopting the above technical solutions, air bubbles in concrete can be effectively stabilized, and their size and distribution can be controlled, thereby improving the uniformity and strength of the concrete. The addition of foam stabilizers helps improve the workability of concrete, reduces problems such as billet adhesion and underdeveloped concrete, increases production efficiency and product quality, and optimizes the concrete's impermeability and crack resistance.

[0021] Secondly, this application provides a method for preparing autoclaved aerated concrete using bottom slag, employing the following technical solution: A method for preparing autoclaved aerated concrete using bottom slag includes the following steps: S1: The lime is crushed by a crusher to pass through a square-hole sieve with a fineness of 0.07-0.09mm. Blast furnace slag, carbon slag, quartz sand and water are mixed to make a slurry. S2: Add all the slurry obtained in S1 to the casting mixer and stir. During the stirring process, add lime and desulfurized gypsum, control the slurry diffusion at 35-38mm, and stir for 2-3 hours. Add the reinforcing fiber to the slurry, stir evenly, let stand for 30-60 minutes, and remove the supernatant. S3: Add silicate cement to the slurry in step S2 and stir until well mixed. Control the slurry diffusion at 20-25cm, the temperature at 40-45℃, and the stirring speed at 400-600r / min. Then add a foam stabilizer to the obtained slurry, stir until well mixed, remove the supernatant, and let it stand at room temperature for 2-3 hours to thicken it, thus obtaining the total slurry. S4: Add aluminum powder to a mixing tank and stir evenly at a stirring speed of 200-300 r / min to obtain aluminum powder liquid. Then add it to the total slurry in step S3, stir for 1-2 minutes, and pour it into the mold. S5: Cur the autoclaved aerated concrete in the mold in a pre-curing chamber at 55-60℃ for 30-40 minutes; then cure it in the curing chamber for 60-90 minutes; after static curing, demold and cut to obtain the blank of the required specifications and dimensions; S6: The billet is transferred to an autoclave for high-temperature and high-pressure steam curing to produce autoclaved aerated concrete.

[0022] By employing the above-mentioned technical solution and precisely controlling the fineness of lime crushing, slurry mixing parameters, and the order of component addition, this preparation method successfully produces autoclaved aerated concrete using bottom slag. This method not only improves the uniformity and strength of the concrete and reduces water absorption, but also fully utilizes the value of industrial waste, achieving the dual goals of environmental protection and high efficiency.

[0023] In summary, this application has the following beneficial effects: 1. Since this application uses granulated blast furnace slag and carbon slag as raw materials for autoclaved aerated products, it can reduce the amount of lime used, weaken the water absorption of raw materials, and reduce the moisture content of products, thereby effectively reducing production problems such as green body sticking and undercooking.

[0024] 2. In this application, microencapsulation treatment of granulated blast furnace slag is preferred, which improves its dispersibility in concrete and reduces the water absorption rate of the coated granulated blast furnace slag, thereby helping to reduce water penetration into the concrete and reduce the occurrence of wall dampness problems.

[0025] 3. The method of this application, by precisely controlling the fineness of lime crushing, slurry mixing parameters and the order of adding each component, not only improves the uniformity and strength of concrete and reduces water absorption, but also fully utilizes the value of industrial waste. Detailed Implementation

[0026] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0027] Preparation example of microencapsulated granulated blast furnace slag Preparation Example 1 A1. Add 250g of ethylene glycol, 2800g of polyester polyol and 450g of diethanolamine to a reaction vessel, dehydrate them, cool them to room temperature, add 1400g of diphenylmethane diisocyanate and 1-3 parts of tertiary amine catalyst, and react at a certain temperature for 2-4 hours to obtain polyurethane prepolymer. A2. When the temperature of the prepolymer drops below 50℃, add 120g of sodium hydroxide and 610g of diphenylmethane diisocyanate and stir evenly. Add 7kg of blast furnace slag to the prepolymer and stir to disperse. Add 1.5kg of deionized water and continue stirring to disperse, thereby obtaining a polyurethane prepolymer dispersion containing blast furnace slag. A3. Add 280g of organic amine aqueous solution to the polyurethane prepolymer dispersion containing blast furnace slag and carry out chain extension reaction to obtain microencapsulated blast furnace slag emulsion with polyurethane as wall material. Vacuum dry the microencapsulated blast furnace slag emulsion and grind it into microencapsulated granulated blast furnace slag with a particle size of 100-500μm using a grinder.

[0028] Preparation Example 2 A1. Add 50g of ethylene glycol, 1000g of polyester polyol and 250g of diethanolamine to a reaction vessel, dehydrate them, cool them to room temperature, add 900g of diphenylmethane diisocyanate and 1-3 parts of tertiary amine catalyst, and react at a certain temperature for 2-4 hours to obtain polyurethane prepolymer. A2. When the temperature of the prepolymer drops below 50℃, add 40g of sodium hydroxide and 400g of diphenylmethane diisocyanate and stir evenly. Add 7kg of blast furnace slag to the prepolymer and stir to disperse. Add 1.5kg of deionized water and continue stirring to disperse, thereby obtaining a polyurethane prepolymer dispersion containing blast furnace slag. A3. Add 80g of organic amine aqueous solution to the polyurethane prepolymer dispersion containing blast furnace slag and carry out chain extension reaction to obtain microencapsulated blast furnace slag emulsion with polyurethane as wall material. Vacuum dry the microencapsulated blast furnace slag emulsion and grind it into microencapsulated granulated blast furnace slag with a particle size of 100-500μm using a grinder.

[0029] Preparation example of surface carbonized straw fiber Preparation Example 3 1 kg of straw was placed in a vacuum heating furnace with an oxygen content of 1%, heated to 650°C, held for 20 minutes, and then cooled with the furnace to obtain surface carbonized straw fiber. Example

[0030] Example 1 A method for preparing autoclaved aerated concrete using bottom slag: S1: The lime is crushed by a crusher to pass through a square hole sieve with a fineness of 0.08mm. 70kg of granulated blast furnace slag, 35kg of carbon slag, 52kg of quartz sand and 55kg of water are mixed to make a slurry. S2: Add all the slurry obtained in S1 to the casting mixer and stir. During the stirring process, add 2 kg of lime and 1.2 kg of desulfurized gypsum, control the slurry diffusion at 35-38 mm, and stir for 3 hours. Add 1.2 kg of surface carbonized straw fiber to the slurry, stir evenly, let stand for 45 minutes, and remove the supernatant. S3: Add 8 kg of silicate cement to the slurry in step S2 and stir until well mixed. Control the slurry diffusion at 23 cm, the temperature at 42 ℃, and the stirring speed at 500 r / min. Then add 0.4 kg of fatty alcohol polyoxyethylene ether silane to the obtained slurry, stir until well mixed, remove the supernatant, and let it stand at room temperature for 3 hours to thicken it, thus obtaining the total slurry. S4: Add 0.3 kg of aluminum powder to a mixing tank and stir evenly at a stirring speed of 250 r / min to obtain aluminum powder liquid. Then add it to the total slurry in step S3, stir for 2 minutes, and pour it into the mold. S5: Cur the autoclaved aerated concrete in the mold in a pre-curing chamber at 58°C for 35 minutes; then cure it in the curing chamber for 70 minutes; after static curing, demold and cut to obtain the blank of the required specifications and dimensions; S6: Transfer the billet to an autoclave and steam it at 8MPa pressure and 180℃ for 12 hours to obtain autoclaved aerated concrete.

[0031] In this process, the granulated blast furnace slag contains Al2O3 > 20%, CaO > 50%, carbon slag particle size is 0.1-0.5 mm, MgO content in the carbon slag is 10-15%, and surface carbonized straw fiber is prepared by Preparation Example 3.

[0032] Example 2 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that 60 kg of granulated blast furnace slag, 30 kg of carbon slag, 40 kg of quartz sand, 5 kg of silicate cement, 1 kg of lime, 1 kg of desulfurized gypsum, 0.2 kg of aluminum powder, 0.5 kg of reinforcing fiber, and 0.2 kg of foam stabilizer are added.

[0033] Example 3 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that 80 kg of granulated blast furnace slag, 40 kg of carbon slag, 60 kg of quartz sand, 10 kg of silicate cement, 5 kg of lime, 2 kg of desulfurized gypsum, 0.4 kg of aluminum powder, 1.5 kg of reinforcing fiber, and 0.5 kg of foam stabilizer are added.

[0034] Example 4 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that the blast furnace slag is microencapsulated granulated blast furnace slag, which was prepared by Example 1.

[0035] Example 5 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that 5-10 kg of zeolite with a particle size of 0.5-2 mm needs to be added in step S1.

[0036] Example 6 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that glass fiber is used as the reinforcing fiber.

[0037] Example 7 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that the Al2O3 content in the granulated blast furnace slag is 15% and the CaO content is 40%.

[0038] Example 8 A method for preparing autoclaved aerated concrete using bottom slag: the difference from Example 1 is that the MgO content in the carbon slag is 5%.

[0039] Example 9 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that the foam stabilizer is fatty alcohol polyoxyethylene ether.

[0040] Comparative Example Comparative Example 1 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 4 is that the microencapsulated granulated blast furnace slag is obtained from Preparation Example 2.

[0041] Comparative Example 2 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that straw fiber is used as the reinforcing fiber.

[0042] Comparative Example 3 A method for preparing autoclaved aerated concrete using bottom slag: The difference from Example 1 is that the amount of granulated blast furnace slag added is 60 kg and lime is 12 kg.

[0043] Performance testing Detection methods Mechanical and water absorption tests were conducted according to the standards specified in GB / T 11969-2008 "Test Methods for Performance of Autoclaved Aerated Concrete". Specimens of the specified dimensions were prepared from the examples and comparative examples. The specimens were left to stand at room temperature for at least 24 hours, then placed on a testing machine and subjected to a vertical axial load until the specimens failed. The compressive strength of the specimens was then calculated.

[0044] According to the standard test method for water absorption of concrete products specified in the national standard GB / T 11968-2014 "Test Method for Water Absorption of Concrete Products", the autoclaved aerated concrete blocks prepared in the examples and comparative examples were tested, and the test results are summarized as follows: Table 1. Statistics on compressive strength and water absorption rate Example 1 6.73 6.35 Example 2 6.32 6.73 Example 3 6.58 6.58 Example 4 6.81 4.97 Example 5 7.13 5.89 Example 6 6.70 6.47 Example 7 6.28 7.15 Example 8 6.50 7.08 Example 9 6.61 6.65 Comparative Example 1 6.53 6.18 Comparative Example 2 6.23 9.53 Comparative Example 3 5.35 12.89 As can be seen from Example 4 and Comparative Example 1, and in conjunction with Table 1, the microencapsulated granulated blast furnace slag prepared by Example 1 can achieve a better coating effect, enabling the blast furnace slag to obtain a better water-repellent and waterproof effect and reduce moisture absorption.

[0045] As can be seen from Example 1 and Comparative Example 2, and Table 1, surface carbonation treatment can also achieve a waterproof effect and reduce the water absorption rate of autoclaved aerated concrete.

[0046] As can be seen from Example 1 and Comparative Example 3, and Table 1, the ratio of granulated blast furnace slag to lime used in this application can achieve better water discharge effect and effectively reduce the water absorption rate of autoclaved aerated concrete.

[0047] As can be seen from Examples 1-3 and Table 1, by adjusting the amount of each component added, not only can the water absorption rate of autoclaved aerated concrete be reduced, but its compressive strength can also be improved. The proportion in Example 1 of this application is the most preferred proportion of this application.

[0048] As can be seen from Examples 1 and 4 and Table 1, microencapsulation of blast furnace slag makes it more stable, which helps to reduce water penetration into concrete, reduce the occurrence of dampness in walls, improve the compressive strength and water absorption of concrete, and enhance the overall performance of concrete.

[0049] As can be seen from Examples 1 and 5 and Table 1, the addition of zeolite particles fills the voids in the concrete, reduces the space for water movement in the concrete, thereby slowing down the rate of water diffusion and reducing the water absorption capacity of the concrete.

[0050] As can be seen from Examples 1, 6-9 and Table 1, high Al2O3 and CaO content helps optimize the pore structure of concrete and reduce water penetration. A MgO content of 10-15% in carbon slag can improve the impermeability and durability of concrete. Using surface-carbonized straw fiber achieves better water absorption reduction than glass fiber, with fatty alcohol polyoxyethylene ether silane being even more superior.

[0051] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. An autoclaved aerated concrete prepared using bottom slag, characterized in that, By weight, it comprises the following components: 60-80 parts granulated blast furnace slag, 30-40 parts carbon slag, 40-60 parts quartz sand, 5-10 parts silicate cement, 1-5 parts lime, 1-2 parts desulfurized gypsum, 0.2-0.4 parts aluminum powder, 0.5-1.5 parts reinforcing fiber, and 0.2-0.5 parts foam stabilizer; The granulated blast furnace slag contains Al2O3 > 20% and CaO > 50%. The carbon slag has a particle size of 0.1-0.5 mm and an MgO content of 10-15%. The reinforcing fiber includes surface-carbonized straw fiber, which is obtained by heating straw fiber to 500-800°C in an environment with an oxygen content of 0.5-1.5% and then cooling it.

2. The autoclaved aerated concrete prepared using bottom slag according to claim 1, characterized in that: The granulated blast furnace slag needs to be microencapsulated. The specific steps of the microencapsulation process are as follows: A1. Add 1-5 parts by weight of ethylene glycol, 15-30 parts by weight of polyester polyol and 3-6 parts by weight of diethanolamine to a reaction vessel for dehydration treatment and cooling to room temperature. Add 10-16 parts by weight of diphenylmethane diisocyanate and 1-3 parts by weight of tertiary amine catalyst, and react at a certain temperature for 2-4 hours to obtain a polyurethane prepolymer. A2. When the temperature of the prepolymer drops below 50°C, add 0.5-2 parts by weight of sodium hydroxide and 5-8 parts by weight of diphenylmethane diisocyanate, and stir evenly. Add 60-80 parts by weight of blast furnace slag to the prepolymer and stir to disperse. Add 10-20 parts by weight of deionized water and continue stirring to disperse, thereby obtaining a polyurethane prepolymer dispersion containing blast furnace slag. A3. Add 1-5 parts of an organic amine aqueous solution to a polyurethane prepolymer dispersion containing blast furnace slag to carry out a chain extension reaction to obtain a microencapsulated blast furnace slag emulsion with polyurethane as the wall material. Vacuum dry the microencapsulated blast furnace slag emulsion and grind it into microencapsulated granulated blast furnace slag with a particle size of 100-500μm using a grinder.

3. The autoclaved aerated concrete prepared using bottom slag according to claim 1, characterized in that: The foam stabilizer is selected from either fatty alcohol polyoxyethylene ether or fatty alcohol polyoxyethylene ether silane.

4. A method for preparing autoclaved aerated concrete using bottom slag as described in any one of claims 1-3, characterized in that: Includes the following steps: S1: Crush lime to pass through a square-hole sieve with a fineness of 0.07-0.09 mm using a crusher. Mix granulated blast furnace slag, carbon slag, quartz sand, and water to prepare a slurry. S2: Add all the slurry obtained in S1 to a casting mixer and stir. During stirring, add lime and desulfurized gypsum, controlling the slurry diffusion at 35-38 mm, and stir for 2-3 hours. Add reinforcing fibers to the slurry, stir evenly, and let stand for 30-60 minutes. Remove the supernatant. S3: Add silicate cement to the slurry from step S2 and stir until homogeneous. Control the slurry diffusion at 20-25 cm, the temperature at 40-45℃, and the stirring speed at 400-600 r / min. Add a foam stabilizer to the resulting slurry, stir evenly, remove the supernatant, and let stand at room temperature for 2-3 hours to thicken, obtaining the total slurry. S4: Add aluminum powder to a mixing tank and stir evenly at a stirring speed of 200-300 r / min to obtain aluminum powder liquid. Then add it to the total slurry in step S3, stir for 1-2 minutes, and pour it into the mold. S5: Cur the autoclaved aerated concrete in the mold in a pre-curing chamber at 55-60℃ for 30-40 minutes; then cure it in a curing chamber for 60-90 minutes; after static curing, demold and cut to obtain the blank of the required specifications and dimensions. S6: The billet is transferred to an autoclave for high-temperature and high-pressure steam curing to produce autoclaved aerated concrete.