Preparation process of fly ash special for construction concrete

Abstract

The application discloses a preparation process of fly ash special for construction concrete, and relates to the technical field of fly ash preparation, which comprises the following steps: preparing raw materials; mixing fly ash and sodium chloride, adding distilled water, uniformly stirring, and obtaining initial mixed solution A; adding a modifier and a surfactant into the initial mixed solution A, and obtaining composite mixed solution B; treating the composite mixed solution B through airflow dispersion, and obtaining modified fly ash slurry; separating the modified fly ash slurry through a centrifugal machine, obtaining solid fly ash after the separation, and then performing drying treatment, and finally obtaining the fly ash for construction. The fly ash modification process improves the surface activity and reactivity of the fly ash by adding sodium chloride, the modifier and the surfactant and combining with the airflow dispersion technology, meanwhile, the airflow dispersion technology effectively improves the dispersibility of the fly ash, increases the contact area of the fly ash and the cement slurry, and thus improves the overall performance of the fly ash.

Description

Technical Field

[0001] This invention relates to the field of fly ash preparation technology, specifically to a preparation process for fly ash specifically for concrete in construction. Background Technology

[0002] Fly ash is an industrial byproduct produced by coal-fired power plants. Its main components are silicon dioxide and aluminum. Due to its low activity, the application of fly ash in concrete construction is limited. Therefore, many studies have focused on improving the performance of fly ash by modifying its preparation process, so that it can better meet the requirements of concrete and enhance its strength and durability.

[0003] Traditional fly ash modification methods typically employ physical, chemical, or biological modifications. However, these methods are either inefficient or fail to effectively improve the overall performance of fly ash. Therefore, a new method is needed that not only enhances the activity of fly ash but also improves its compatibility with concrete, thereby improving concrete performance. Currently, there is no unified standard for the preparation of modified fly ash. Due to the diverse properties and sources of fly ash, and the lack of standardized modification processes, the application effects of fly ash vary considerably. Therefore, developing a stable and easy-to-operate modified fly ash preparation process has become an urgent need in the industry. Summary of the Invention

[0004] To solve the above-mentioned technical problems, a preparation process for fly ash specifically for concrete construction is provided. This technical solution solves the aforementioned problems.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A process for preparing fly ash specifically for concrete construction includes:

[0007] S1: Prepare the following raw materials in the following proportions: 100-1000 parts fly ash, 3-30 parts sodium chloride, 1-10 parts modifier, 2-20 parts surfactant, and 100-800 parts distilled water.

[0008] S2: Mix fly ash with sodium chloride, add distilled water, and stir well to obtain initial mixture A;

[0009] S3: Add modifier and surfactant to the initial mixture A, and continue stirring at a speed of 60-120 r / min for 30-60 minutes to obtain composite mixture B;

[0010] S4: The composite mixture B is dispersed by airflow at a temperature of 80-120℃ for 10-20 minutes to obtain modified fly ash slurry;

[0011] S5: The modified fly ash slurry is separated by a centrifuge to obtain solid fly ash, which is then dried at a temperature of 70-100℃ to obtain the final fly ash for construction.

[0012] Preferably, the specific proportions of raw materials in step S1 are: 500 parts fly ash, 15 parts sodium chloride, 5 parts modifier, 10 parts surfactant, and 400 parts distilled water.

[0013] Preferably, the fly ash is highly active fly ash containing 60% to 80% silica and aluminum, the modifier is a polymer with a high molecular chain structure, the surfactant is sodium dodecylbenzenesulfonate, the airflow dispersion treatment temperature is 100°C, the treatment time is 15 minutes, and the fly ash particle size in the obtained modified fly ash slurry is 1-5 μm.

[0014] Preferably, the preparation process further includes a quality inspection step for the final product, including particle size distribution testing, specific surface area testing, flowability testing, and bonding strength testing. The bonding strength test is performed using standard mortar to evaluate the performance of fly ash.

[0015] Preferably, S2 specifically includes:

[0016] Use a precision balance to weigh fly ash and sodium chloride, ensuring that the ratio of fly ash to sodium chloride meets the formula requirements, and record the quality of the raw materials;

[0017] Weigh out the fly ash and sodium chloride and put them into a mixing container in the required ratio. Dry mix them at a speed of 30-50 r / min to ensure that they are mixed evenly. The mixing time is 5-10 minutes.

[0018] Gradually add distilled water to the container, the amount of water being 100-800 parts. During the addition process, maintain a stirring speed of 30-50 r / min to ensure that the water is evenly distributed in the fly ash and sodium chloride mixture.

[0019] Continue stirring the mixture for 15-30 minutes to ensure that the fly ash, sodium chloride, and distilled water are completely mixed to form a uniform initial mixture A. During the stirring process, check the appearance of the liquid regularly to ensure that there is no particle aggregation or stratification.

[0020] Preferably, S3 specifically includes:

[0021] Slowly add the weighed modifier and surfactant to the initial mixture A in several portions, ensuring that they are mixed evenly after each addition.

[0022] After the modifier and surfactant are added to the initial mixture A, continue stirring at a speed of 60-120 r / min to ensure that the modifier and surfactant are completely dissolved and react fully with the fly ash and sodium chloride in the initial mixture A.

[0023] Maintain stirring time for 30-60 minutes, checking the uniformity of the mixture during this period. The stirring speed can be adjusted appropriately to ensure that the modifier and surfactant can be completely mixed with fly ash and sodium chloride to form a uniform composite mixture B.

[0024] During the stirring process, regularly observe the appearance of the composite mixture B to ensure that the liquid is uniform and free from obvious sedimentation and stratification.

[0025] Preferably, S4 specifically includes:

[0026] Slowly heat the composite mixture B to a temperature range of 80-120℃, and use a temperature control system to maintain a stable temperature.

[0027] The composite mixture B is dispersed by high-pressure airflow, so that the fly ash particles in the composite mixture are quickly dispersed by the airflow, thereby enhancing its surface modification effect.

[0028] During the airflow dispersion process, the airflow velocity, pressure, and temperature are precisely controlled, with the airflow pressure maintained within the range of 0.2-0.5 MPa.

[0029] During the airflow dispersion process, the temperature and processing time are continuously monitored to ensure that the temperature is maintained between 80-120℃ and the processing time is 10-20 minutes. Temperature sensors and time control systems are used to ensure the accuracy of airflow dispersion.

[0030] An airflow dispersion tank is used to ensure that the dispersed fly ash particles are evenly distributed in the liquid.

[0031] While the airflow is being dispersed, stirring continues, and the temperature sensor and pressure gauge are monitored in real time to observe the temperature and pressure changes during the airflow dispersion process.

[0032] After the airflow dispersion treatment is completed, the modified fly ash slurry is collected and post-treated.

[0033] Preferably, the step of collecting the modified fly ash slurry and performing post-treatment after the airflow dispersion treatment specifically includes:

[0034] After the airflow dispersion treatment is completed, the modified fly ash slurry is cooled by using a cooling system or by gradually reducing the temperature of the slurry to 20-30℃ to ensure that the air pressure of the slurry is stable during the cooling process.

[0035] After cooling, the slurry is placed in a settling container and allowed to settle. The settling time is 1-2 hours to ensure that large fly ash particles in the slurry settle to the bottom of the container.

[0036] Based on the stratification phenomenon after sedimentation, the upper clear liquid is manually poured out, while the precipitate is retained;

[0037] The settled slurry is transferred to a centrifuge for centrifugation. The centrifuge speed is set in the range of 3000-5000 rpm and the centrifugation time is 10-15 minutes to further remove particulate impurities and obtain fly ash slurry.

[0038] Preferably, S5 specifically includes:

[0039] The modified fly ash slurry after air dispersion treatment is transferred to the centrifuge tube of a centrifuge. The centrifuge speed and time are set. The centrifuge speed is set to 3000-5000 rpm and the centrifugation time is 10-15 minutes.

[0040] Through centrifugal force, the solid fly ash particles in the slurry are pulled to the bottom of the pipe, and the liquid part is separated to the upper layer. After centrifugation, the solid fly ash part at the bottom is collected and the liquid at the top is separated.

[0041] The solid fly ash obtained by centrifugation is washed with deionized water to remove the residues adhering to the surface of the solid fly ash.

[0042] The cleaning solution is added to the fly ash, stirred and allowed to stand, and then separated by a centrifuge to ensure that impurities in the cleaning solution are removed.

[0043] After cleaning, the solid fly ash is transferred to a drying equipment for vacuum drying. The drying temperature is set between 70-100℃, and the drying time is 6-12 hours. The temperature and humidity are checked regularly during the drying process.

[0044] Preferably, if the dried fly ash particles are uneven, they are crushed and sieved using a screen to remove unqualified particles.

[0045] The treated fly ash is packaged and stored in a dry warehouse.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] The fly ash modification process proposed in this invention significantly enhances the surface activity and reactivity of fly ash by adding additives such as sodium chloride, modifiers, and surfactants, combined with airflow dispersion technology. This strengthens the fly ash's bonding ability with concrete components. Simultaneously, the airflow dispersion technology effectively improves the fly ash's dispersibility, increasing the contact area with cement paste, thereby improving the overall performance of the fly ash. The modified fly ash has a more optimized particle size distribution, allowing for better reaction with cement and improving the strength and durability of concrete, particularly for high-strength concrete. Furthermore, the modified fly ash exhibits good flowability and workability, improving construction performance. This process is applicable to fly ash from different sources and with varying compositions, especially highly reactive fly ash. It offers strong environmental and resource utilization advantages, aligns with sustainable development requirements, is simple to operate, highly adaptable, and ensures the stability and quality of fly ash, meeting the high standards required for concrete engineering. Attached Figure Description

[0048] Figure 1 This is a flowchart illustrating the steps of the present invention. Detailed Implementation

[0049] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0050] Reference Figure 1 As shown, a process for preparing fly ash specifically for concrete construction includes:

[0051] S1: Prepare the following raw materials in the following proportions: 100-1000 parts fly ash, 3-30 parts sodium chloride, 1-10 parts modifier, 2-20 parts surfactant, and 100-800 parts distilled water.

[0052] S2: Mix fly ash with sodium chloride, add distilled water, and stir well to obtain initial mixture A;

[0053] S3: Add modifier and surfactant to the initial mixture A, and continue stirring at a speed of 60-120 r / min for 30-60 minutes to obtain composite mixture B;

[0054] S4: The composite mixture B is dispersed by airflow at a temperature of 80-120℃ for 10-20 minutes to obtain modified fly ash slurry;

[0055] S5: The modified fly ash slurry is separated by a centrifuge to obtain solid fly ash, which is then dried at a temperature of 70-100℃ to obtain the final fly ash for construction.

[0056] The specific proportions of raw materials in step S1 are: 500 parts fly ash, 15 parts sodium chloride, 5 parts modifier, 10 parts surfactant, and 400 parts distilled water.

[0057] The fly ash is highly active fly ash containing 60% to 80% silica and aluminum. The modifier is a polymer with a high molecular chain structure, and the surfactant is sodium dodecylbenzenesulfonate. The airflow dispersion treatment is carried out at a temperature of 100°C for 15 minutes, and the fly ash particle size in the resulting modified fly ash slurry is 1-5 μm.

[0058] The preparation process also includes quality testing steps for the final product, including particle size distribution testing, specific surface area testing, flowability testing, and bond strength testing. The bond strength test is conducted using standard mortar to evaluate the performance of fly ash.

[0059] S2 specifically includes:

[0060] Use a precision balance to weigh fly ash and sodium chloride, ensuring that the ratio of fly ash to sodium chloride meets the formula requirements, and record the quality of the raw materials;

[0061] Weigh out the fly ash and sodium chloride and put them into a mixing container in the required ratio. Dry mix them at a speed of 30-50 r / min to ensure that they are mixed evenly. The mixing time is 5-10 minutes.

[0062] Gradually add distilled water to the container, the amount of water being 100-800 parts. During the addition process, maintain a stirring speed of 30-50 r / min to ensure that the water is evenly distributed in the fly ash and sodium chloride mixture.

[0063] Continue stirring the mixture for 15-30 minutes to ensure that the fly ash, sodium chloride, and distilled water are completely mixed to form a uniform initial mixture A. During the stirring process, check the appearance of the liquid regularly to ensure that there is no particle aggregation or stratification.

[0064] S3 specifically includes:

[0065] Slowly add the weighed modifier and surfactant to the initial mixture A in several portions, ensuring that they are mixed evenly after each addition.

[0066] After the modifier and surfactant are added to the initial mixture A, continue stirring at a speed of 60-120 r / min to ensure that the modifier and surfactant are completely dissolved and react fully with the fly ash and sodium chloride in the initial mixture A.

[0067] Maintain stirring time for 30-60 minutes, checking the uniformity of the mixture during this period. The stirring speed can be adjusted appropriately to ensure that the modifier and surfactant can be completely mixed with fly ash and sodium chloride to form a uniform composite mixture B.

[0068] During the stirring process, regularly observe the appearance of the composite mixture B to ensure that the liquid is uniform and free from obvious sedimentation and stratification.

[0069] S4 specifically includes:

[0070] Slowly heat the composite mixture B to a temperature range of 80-120℃, and use a temperature control system to maintain a stable temperature.

[0071] The composite mixture B is dispersed by high-pressure airflow, so that the fly ash particles in the composite mixture are quickly dispersed by the airflow, thereby enhancing its surface modification effect.

[0072] During the airflow dispersion process, the airflow velocity, pressure, and temperature are precisely controlled, with the airflow pressure maintained within the range of 0.2-0.5 MPa.

[0073] During the airflow dispersion process, the temperature and processing time are continuously monitored to ensure that the temperature is maintained between 80-120℃ and the processing time is 10-20 minutes. Temperature sensors and time control systems are used to ensure the accuracy of airflow dispersion.

[0074] An airflow dispersion tank is used to ensure that the dispersed fly ash particles are evenly distributed in the liquid.

[0075] While the airflow is being dispersed, stirring continues, and the temperature sensor and pressure gauge are monitored in real time to observe the temperature and pressure changes during the airflow dispersion process.

[0076] After the airflow dispersion treatment is completed, the modified fly ash slurry is collected and post-treated.

[0077] After the airflow dispersion treatment is completed, the collection and post-treatment of the modified fly ash slurry specifically includes:

[0078] After the airflow dispersion treatment is completed, the modified fly ash slurry is cooled by using a cooling system or by gradually reducing the temperature of the slurry to 20-30℃ to ensure that the air pressure of the slurry is stable during the cooling process.

[0079] After cooling, the slurry is placed in a settling container and allowed to settle. The settling time is 1-2 hours to ensure that large fly ash particles in the slurry settle to the bottom of the container.

[0080] Based on the stratification phenomenon after sedimentation, the upper clear liquid is manually poured out, while the precipitate is retained;

[0081] The settled slurry is transferred to a centrifuge for centrifugation. The centrifuge speed is set in the range of 3000-5000 rpm and the centrifugation time is 10-15 minutes to further remove particulate impurities and obtain fly ash slurry.

[0082] S5 specifically includes:

[0083] The modified fly ash slurry after air dispersion treatment is transferred to the centrifuge tube of a centrifuge. The centrifuge speed and time are set. The centrifuge speed is set to 3000-5000 rpm and the centrifugation time is 10-15 minutes.

[0084] Through centrifugal force, the solid fly ash particles in the slurry are pulled to the bottom of the pipe, and the liquid part is separated to the upper layer. After centrifugation, the solid fly ash part at the bottom is collected and the liquid at the top is separated.

[0085] The solid fly ash obtained by centrifugation is washed with deionized water to remove the residues adhering to the surface of the solid fly ash.

[0086] The cleaning solution is added to the fly ash, stirred and allowed to stand, and then separated by a centrifuge to ensure that impurities in the cleaning solution are removed.

[0087] After cleaning, the solid fly ash is transferred to a drying equipment for vacuum drying. The drying temperature is set between 70-100℃, and the drying time is 6-12 hours. The temperature and humidity are checked regularly during the drying process.

[0088] 10. The preparation process of fly ash for concrete construction according to claim 9, characterized in that:

[0089] If the dried fly ash particles are uneven, they should be crushed and screened to remove unqualified particles.

[0090] The processed fly ash is packaged and stored in a dry warehouse.

[0091] Example 1:

[0092] A preparation process for fly ash specifically for concrete construction, comprising the following steps:

[0093] S1: Prepare the following raw materials in the following quantities: 500 parts fly ash, 15 parts sodium chloride, 5 parts modifier, 10 parts surfactant, and 400 parts distilled water.

[0094] S2: Mix fly ash with sodium chloride, add distilled water, and stir well to obtain initial mixture A;

[0095] S3: Add modifier and surfactant to the initial mixture A, continue stirring at a speed of 90 r / min for 45 minutes to obtain composite mixture B;

[0096] S4: The composite mixture B is dispersed by airflow at a temperature of 100℃ for 15 minutes to obtain modified fly ash slurry;

[0097] S5: The modified fly ash slurry is separated by a centrifuge to obtain solid fly ash, which is then dried at a temperature of 85℃ to obtain the final fly ash for construction.

[0098] Example 2:

[0099] A preparation process for fly ash specifically for concrete construction, comprising the following steps:

[0100] S1: Prepare the following raw materials in the following proportions: 300 parts fly ash, 10 parts sodium chloride, 3 parts modifier, 5 parts surfactant, and 250 parts distilled water.

[0101] S2: Mix fly ash with sodium chloride, add distilled water, and stir well to obtain initial mixture A;

[0102] S3: Add modifier and surfactant to the initial mixture A, continue stirring at a speed of 80 r / min for 35 minutes to obtain composite mixture B;

[0103] S4: The composite mixture B is dispersed by airflow at a temperature of 90℃ for 12 minutes to obtain modified fly ash slurry;

[0104] S5: The modified fly ash slurry is separated by a centrifuge to obtain solid fly ash, which is then dried at a temperature of 75℃ to obtain the final fly ash for construction.

[0105] Example 3:

[0106] A preparation process for fly ash specifically for concrete construction, comprising the following steps:

[0107] S1: Prepare the following raw materials in the following quantities: 800 parts fly ash, 20 parts sodium chloride, 8 parts modifier, 15 parts surfactant, and 700 parts distilled water.

[0108] S2: Mix fly ash with sodium chloride, add distilled water, and stir well to obtain initial mixture A;

[0109] S3: Add modifier and surfactant to the initial mixture A, and continue stirring at a speed of 110 r / min for 50 minutes to obtain composite mixture B;

[0110] S4: The composite mixture B is dispersed by airflow at a temperature of 110℃ for 18 minutes to obtain modified fly ash slurry;

[0111] S5: The modified fly ash slurry is separated by a centrifuge to obtain solid fly ash, which is then dried at a temperature of 95℃ to obtain the final fly ash for construction.

[0112] Comparative Example 1

[0113] The fly ash for construction prepared by methods other than those of the present invention, which are prepared by traditional methods without multi-component compounding and airflow dispersion treatment, has a larger particle size, uneven particle size, poor stability, easy moisture absorption, and poor flowability. Its actual application effect is not as good as that of Examples 1, 2 and 3.

[0114] The following table shows the properties of fly ash for construction prepared in different embodiments:

[0115]

[0116]

[0117] In summary, the advantages of this invention are as follows:

[0118] The fly ash modification process provided by this invention, by adding additives such as sodium chloride, modifiers and surfactants, combined with airflow dispersion technology, can effectively improve the surface activity of fly ash, thereby significantly enhancing its reactivity and bonding ability in concrete.

[0119] By employing airflow dispersion technology, fly ash particles can be effectively dispersed into the slurry, increasing the contact area between fly ash and cement paste, thereby enhancing its reactivity with other components in concrete and improving the overall performance of fly ash.

[0120] By optimizing the particle size distribution and surface activity of fly ash, the modified fly ash can react better with cement, generate more hydration products, and improve the strength and durability of concrete, especially for the use of high-strength concrete, where it has a better effect.

[0121] The fly ash processed by the process of this invention has better fluidity and workability, making it perform better in concrete mixing and construction, and reducing the construction difficulty caused by coarse or unevenly dispersed fly ash particles.

[0122] This process is applicable to fly ash from different sources and with different compositions, and it has a significant modification effect, especially on highly reactive fly ash. Therefore, it can be used in a variety of construction environments.

[0123] The process of this invention utilizes fly ash, an industrial byproduct, and improves its performance through modification treatment. This not only solves the waste disposal problem but also enhances resource utilization efficiency, meeting the requirements of sustainable development. The process steps are simple and easy to operate, and can be adjusted according to different production needs, thus having high industrial application value and economic benefits.

[0124] By precisely controlling each step and conducting rigorous quality testing, we ensure that the final fly ash used in construction has uniform particle size and stable quality, meeting the high standards required for concrete engineering.

[0125] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A preparation process for fly ash specifically for concrete construction, characterized in that, include: S1: Prepare the following raw materials in the following proportions: 100-1000 parts fly ash, 3-30 parts sodium chloride, 1-10 parts modifier, 2-20 parts surfactant, and 100-800 parts distilled water. S2: Mix fly ash with sodium chloride, add distilled water, and stir well to obtain initial mixture A; S3: Add modifier and surfactant to the initial mixture A, and continue stirring at a speed of 60-120 r / min for 30-60 minutes to obtain composite mixture B; S4: The composite mixture B is dispersed by airflow at a temperature of 80-120℃ for 10-20 minutes to obtain modified fly ash slurry; S5: The modified fly ash slurry is separated by a centrifuge to obtain solid fly ash, which is then dried at a temperature of 70-100℃ to obtain the final fly ash for construction. S5 specifically includes: The modified fly ash slurry after air dispersion treatment is transferred to the centrifuge tube of a centrifuge. The centrifuge speed and time are set. The centrifuge speed is set to 3000-5000 rpm and the centrifugation time is 10-15 minutes. Through centrifugal force, the solid fly ash particles in the slurry are pulled to the bottom of the pipe, and the liquid part is separated to the upper layer. After centrifugation, the solid fly ash part at the bottom is collected and the liquid at the top is separated. The solid fly ash obtained by centrifugation is washed with deionized water to remove the residues adhering to the surface of the solid fly ash. The cleaning solution is added to the fly ash, stirred and allowed to stand, and then separated by a centrifuge to ensure that impurities in the cleaning solution are removed. After cleaning, the solid fly ash is transferred to a drying equipment for vacuum drying. The drying temperature is set between 70-100℃ and the drying time is 6-12 hours. The temperature and humidity are checked regularly during the drying process. If the dried fly ash particles are uneven, they should be crushed and screened to remove unqualified particles. The treated fly ash is packaged and stored in a dry warehouse.

2. The preparation process of fly ash for concrete construction according to claim 1, characterized in that: The specific proportions of raw materials in step S1 are: 500 parts fly ash, 15 parts sodium chloride, 5 parts modifier, 10 parts surfactant, and 400 parts distilled water.

3. The preparation process of fly ash for concrete construction according to claim 2, characterized in that: The fly ash is highly active fly ash containing 60% to 80% silica and aluminum. The modifier is a polymer with a high molecular chain structure. The surfactant is sodium dodecylbenzenesulfonate. The airflow dispersion treatment is carried out at a temperature of 100°C for 15 minutes. The fly ash particle size in the resulting modified fly ash slurry is 1-5 μm.

4. The preparation process of fly ash for concrete construction according to claim 3, characterized in that, The preparation process also includes quality testing steps for the final product, including particle size distribution testing, specific surface area testing, flowability testing, and bonding strength testing. The bonding strength test is conducted using standard mortar to evaluate the performance of fly ash.

5. The preparation process of fly ash for concrete construction according to claim 4, characterized in that, S2 specifically includes: Use a precision balance to weigh fly ash and sodium chloride, ensuring that the ratio of fly ash to sodium chloride meets the formula requirements, and record the quality of the raw materials; Weigh out the fly ash and sodium chloride and put them into a mixing container in the required ratio. Dry mix them at a speed of 30-50 r / min to ensure that they are mixed evenly. The mixing time is 5-10 minutes. Gradually add distilled water to the container, the amount of water being 100-800 parts. During the addition process, maintain a stirring speed of 30-50 r / min to ensure that the water is evenly distributed in the fly ash and sodium chloride mixture. Continue stirring the mixture for 15-30 minutes to ensure that the fly ash, sodium chloride, and distilled water are completely mixed to form a uniform initial mixture A. During the stirring process, check the appearance of the liquid regularly to ensure that there is no particle aggregation or stratification.

6. The preparation process of fly ash for concrete construction according to claim 5, characterized in that, S3 specifically includes: Slowly add the weighed modifier and surfactant to the initial mixture A in several portions, ensuring that they are mixed evenly after each addition. After the modifier and surfactant are added to the initial mixture A, continue stirring at a speed of 60-120 r / min to ensure that the modifier and surfactant are completely dissolved and react fully with the fly ash and sodium chloride in the initial mixture A. Maintain stirring time for 30-60 minutes, checking the uniformity of the mixture during this period. Adjust the stirring speed appropriately to ensure that the modifier and surfactant can be completely mixed with fly ash and sodium chloride to form a uniform composite mixture B. During the stirring process, regularly observe the appearance of the composite mixture B to ensure that the liquid is uniform and free from obvious sedimentation and stratification.

7. The preparation process of fly ash for concrete construction according to claim 6, characterized in that, S4 specifically includes: Slowly heat the composite mixture B to a temperature range of 80-120℃, and use a temperature control system to maintain a stable temperature. The composite mixture B is dispersed by high-pressure airflow, so that the fly ash particles in the composite mixture are quickly dispersed by the airflow, thereby enhancing its surface modification effect. During the airflow dispersion process, the airflow velocity, pressure, and temperature are precisely controlled, with the airflow pressure maintained within the range of 0.2-0.5 MPa. During the airflow dispersion process, the temperature and processing time are continuously monitored to ensure that the temperature is maintained between 80-120℃ and the processing time is 10-20 minutes. Temperature sensors and time control systems are used to ensure the accuracy of airflow dispersion. An airflow dispersion tank is used to ensure that the dispersed fly ash particles are evenly distributed in the liquid. While the airflow is being dispersed, stirring continues, and the temperature sensor and pressure gauge are monitored in real time to observe the temperature and pressure changes during the airflow dispersion process. After the airflow dispersion treatment is completed, the modified fly ash slurry is collected and post-treated.

8. The preparation process of fly ash for concrete construction according to claim 7, characterized in that, The process of collecting and post-treating the modified fly ash slurry after the airflow dispersion treatment specifically includes: After the airflow dispersion treatment is completed, the modified fly ash slurry is cooled by using a cooling system or by gradually reducing the temperature of the slurry to 20-30℃ to ensure that the air pressure of the slurry is stable during the cooling process. After cooling, the slurry is placed in a settling container and allowed to settle. The settling time is 1-2 hours to ensure that large fly ash particles in the slurry settle to the bottom of the container. Based on the stratification phenomenon after sedimentation, the upper clear liquid is manually poured out, while the precipitate is retained; The settled slurry is transferred to a centrifuge for centrifugation. The centrifuge speed is set in the range of 3000-5000 rpm and the centrifugation time is 10-15 minutes to further remove particulate impurities and obtain fly ash slurry.

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