Calcium aluminate-calcium silicate-based silicon-aluminum solid waste activating agent as well as preparation method and application thereof

Abstract

The invention discloses a calcium aluminate-calcium silicate-based silicon-aluminum solid waste activating agent and a preparation method and application thereof, and belongs to the technical field of solid waste activation, the activating agent comprises the following components in parts by mass: 10-30 parts of calcium aluminate, 10-30 parts of active calcium silicate, 1-5 parts of a sodium sulfate or potassium sulfate auxiliary exciting agent and 0.5-2 parts of a polycarboxylic acid type dispersing agent, the mass ratio of calcium aluminate to calcium silicate is 1: 2, 2: 1 or 1: 1. The preparation method comprises the following steps: drying the raw materials, preparing ultrafine powder, performing high-strength mechanical mixing, screening and packaging, and ensuring the uniformity and activity of the components through a refining process. The activating agent is suitable for concrete or mortar of a silicon-aluminum solid waste-based cementing material system, the mixing amount is 1%-5% of the total mass of the cementing material, and the process of wet mixing after dry mixing is adopted for construction. Through multi-component synergistic excitation, the problems that an existing activation technology is prone to saltpetering, out-of-control in condensation, poor in volume stability, limited in single-component performance and the like are effectively solved, and the resource utilization rate of the silicon-aluminum solid waste is increased.

Description

Technical Field

[0001] This invention relates to the field of solid waste activation technology, and in particular to calcium aluminate-calcium silicate-based silicoaluminate solid waste activator, its preparation method, and its application. Background Technology

[0002] Silica-alumina solid wastes (such as slag, fly ash, metakaolin, and coal gangue) are bulk wastes generated during industrial production. Their resource utilization is not only crucial for ecological environmental protection but also plays a vital role in promoting the green and low-carbon development of the building materials industry. Currently, activation technologies for these solid wastes have become a research hotspot in the industry, aiming to stimulate their potential cementitious activity through various technical means, transforming them into cementitious material components that can replace traditional cement, thus achieving the dual goals of waste reduction and resource recovery. However, while existing mainstream activation technologies have shown some potential in application, they still have many inherent defects, making it difficult to meet the needs of preparing high-performance cementitious materials and limiting the large-scale, high-value-added utilization of silica-alumina solid wastes.

[0003] Among various activation technologies, strong alkali activation technology is the most widely used. It typically uses strong alkalis such as water glass and sodium hydroxide as activators to disrupt the crystal structure of aluminosilicate solid waste, promoting the dissolution of aluminum and silicon ions and forming gel products. However, this technology has significant drawbacks. The setting and hardening rate of the strong alkali system is difficult to control precisely, easily leading to problems such as early rapid setting or late slow setting, which seriously affects the workability of construction. Strong alkali components tend to accumulate on the material surface and migrate and precipitate with moisture, causing the "efflorescence" phenomenon, which not only reduces the appearance quality of the material but also weakens the interfacial bonding strength, affecting the structural durability. In addition, gel materials prepared by strong alkali activation are often brittle, have poor volume stability, and are prone to shrinkage cracks, thereby reducing the service life of the structure.

[0004] The technical approach of relying solely on chemical activation (such as sulfate activation) also has limitations. For low-activity or highly crystalline siliceous aluminate solid waste, a single chemical activator is insufficient to fully break its stable crystal structure, resulting in low aluminum and silicon ion dissolution rates and insufficient formation of cementitious products. Ultimately, this prevents the material from meeting the requirements for high-performance cementitious materials in terms of key properties such as strength and durability. While physical activation methods such as mechanical and thermal activation can improve the activity of solid waste to some extent, mechanical activation suffers from excessive energy consumption and low treatment efficiency, while thermal activation faces the dilemma of large equipment investment and high operating costs. Furthermore, the high-temperature treatment process may generate secondary pollutants, causing new environmental problems and hindering the industrial-scale promotion of the technology.

[0005] To compensate for the shortcomings of single activation technologies, the industry is increasingly inclined to adopt a strategy of using multiple activation methods in combination, improving activation effects through component blending and technological synergy. However, existing composite activation technologies still suffer from a lack of refined design, especially for key components such as calcium aluminate and calcium silicate, which have different hydration activity sequences. Their blending systems lack a systematic design based on hydration mechanisms. Calcium aluminate is characterized by high early hydration activity and rapid heat release, while calcium silicate focuses more on the formation of later gelling products and strength development. The simple physical mixing methods in existing technologies fail to effectively utilize the heat and alkalinity released by calcium aluminate during early hydration to fully stimulate the potential activity of calcium silicate, resulting in the synergistic effect of the two components not being fully realized. These defects directly lead to the difficulty in synergistically optimizing the performance of gelling materials from early coagulation to later enhancement in the blended activation system. Either the early strength is insufficient, affecting construction progress and efficiency; or the later strength growth is slow, and the structural durability is poor, failing to balance workability and long-term service stability.

[0006] Therefore, developing a composite activation system based on hydration mechanism, which can achieve synergistic activation of different active components by precisely controlling the component ratio and preparation process, taking into account both the early performance and later durability of cementitious materials, while avoiding various defects of existing technologies, has become an urgent technical problem to be solved in the field of resource utilization of siliceous aluminate solid waste. Summary of the Invention

[0007] The purpose of this invention is to provide a calcium aluminate-calcium silicate-based silicoaluminate solid waste activator, its preparation method, and its application, in order to solve the above-mentioned problems.

[0008] This invention provides a calcium aluminate-calcium silicate-based silicoaluminate solid waste activator, comprising the following components by mass: 10-30 parts of calcium aluminate, which, when added to a cement system, can rapidly react with water and gypsum to form a hydrated calcium aluminate phase, accelerating the hydration process of C3A minerals in cement; 10-30 parts of calcium silicate, which is an active calcium silicate that is not cement clinker, and whose silicate ions, provided by itself or during hydration, can preferentially combine with calcium ions in the slurry to form CSH gel nuclei; 1-5 parts of auxiliary activator; and 0.5-2 parts of dispersant.

[0009] Preferably, the mass ratio of calcium aluminate to calcium silicate is 1:2, 2:1 or 1:1, and the amount of activator in the silica-alumina solid waste-based cementitious system is 1%-5% of the total mass of the silica-alumina solid waste-based cementitious material.

[0010] Preferably, the auxiliary activator is sodium sulfate or potassium sulfate, which can quickly dissolve and release sulfate ions to react with calcium aluminate, calcium silicate and other components in the system, promoting the rapid formation of ettringite early strength products; the dispersant is a polycarboxylate superplasticizer, which disperses fine particles through steric hindrance and electrostatic repulsion, breaking the particle agglomeration state.

[0011] Preferably, each powder component in the activator is subjected to ultrafine grinding, resulting in a specific surface area ≥ 400 m². 2 / kg.

[0012] A method for preparing the calcium aluminate-calcium silicate-based aluminosilicate solid waste activator as described above is provided, comprising the following steps: S1. Raw material drying: Dry the calcium aluminate, calcium silicate raw materials, and auxiliary activators, dispersants and additives at 105±5℃ to constant weight; S2. Powder grinding: The dried raw materials are ground separately using a planetary ball mill until the specific surface area is ≥400 m². 2 / kg, and then sieved through a 45μm sieve to remove coarse particles; S3. Dry powder mixing: The ground and sieved calcium aluminate and calcium silicate powders are mixed with the dry powder dispersant and auxiliary activator in a dry state using a V-type mixer or a high-efficiency dry powder mixer to ensure that the components are mixed evenly. S4. Screening and Packaging: Pass the uniformly mixed dry powder product through a 325-mesh sieve. After passing the screening, package the product to obtain dry powder calcium aluminate-calcium silicate-based silica-alumina solid waste activator.

[0013] An application of the calcium aluminate-calcium silicate-based silicoaluminate solid waste activator described above is provided. The activator is applied to concrete or mortar systems in which silicoaluminate solid waste is used as a cementing material. The mix proportion of the silicoaluminate solid waste-based cementing material is as follows by mass percentage: cement 40%, slag 10%, fly ash 20%, metakaolin 20%, silica fume 10%, water-cement ratio 0.4, and mortar-cement ratio 0.3. The dosage of the activator is 1%-5% of the total mass of the silicoaluminate solid waste-based cementing material. During construction, a dry-mixing followed by wet-mixing process is adopted, and it is used in conjunction with a polycarboxylate superplasticizer.

[0014] Preferably, the activator is classified into single-component and multi-component types according to its component type; the single-component type contains only calcium aluminate component and is suitable for construction occasions requiring ultra-high strength within 1 day or 12 hours; the multi-component type contains calcium aluminate and calcium silicate components and is suitable for construction occasions that need to take into account early strength performance, later strength growth and durability.

[0015] Preferably, the specific operating steps during construction are as follows: Step 1: Determine the dosage of activator according to the performance requirements of mortar. Take the corresponding dosage of activator and mix it with one-third of the total water volume for mortar mixing. Use a mechanical mixer to stir for 2-4 minutes until the mixture is uniform to obtain the activator solution. Step 2: Pour the dry powder components of the mortar into the mixer, add the activator solution, then add the remaining water and sand in sequence, and use a mechanical mixer to mix until the mortar is evenly mixed; Step 3: Quickly pour, plaster, or grout the well-mixed mortar.

[0016] Therefore, the present invention, employing the above-mentioned calcium aluminate-calcium silicate-based aluminosilicate solid waste activator, its preparation method, and its application, has the following beneficial effects: (1) The calcium aluminate mineral in the activator can be rapidly hydrated, significantly improving the early strength of the cementitious system; at the same time, its components can synergistically react with the active silicon-aluminum components in solid waste, optimizing the microstructure and thus continuously improving the activity index of solid waste. Compared with traditional methods such as strong alkali activation, this mineral-based activation method can more stably and controllably activate the potential of solid waste and help improve the long-term durability of materials, providing an innovative path for the high-value-added resource utilization of solid waste.

[0017] (2) The compounding system can optimize the composition and structure of hydration products, promote the formation of a denser and more uniform microstructure, thereby reducing the volume change caused by water evaporation and chemical shrinkage during the hardening process, effectively inhibiting shrinkage and the generation of microcracks, and improving the long-term dimensional stability of the material.

[0018] (3) This accelerator does not contain harmful components such as chloride ions, completely eliminating the risk of steel corrosion introduced by admixtures. It is particularly suitable for reinforced concrete structures with strict anti-corrosion requirements, which helps to extend the service life of the structure and improve its durability in harsh environments.

[0019] (4) By using bulk industrial solid waste as the main raw material, waste treatment is achieved at the source, which greatly reduces the cost of raw materials. At the same time, its preparation process does not require high temperature or complex chemical treatment, the process is simple and energy consumption is low, which further reduces the production cost.

[0020] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0021] To better understand the above technical solutions, a detailed description of the specific implementation methods will be provided below. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.

[0023] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.

[0024] This invention provides a calcium aluminate-calcium silicate-based silicoaluminate solid waste activator, comprising the following components by mass: 10-30 parts of calcium aluminate, which, when added to a cement system, can rapidly react with water and gypsum to form a hydrated calcium aluminate phase, accelerating the hydration process of C3A minerals in cement; 10-30 parts of calcium silicate, wherein the calcium silicate is an active calcium silicate that is not a cement clinker, and the silicate ions provided by the calcium silicate itself or during the hydration process can preferentially combine with calcium ions in the slurry to form CSH gel nuclei; 1-5 parts of auxiliary activator; and 0.5-2 parts of dispersant.

[0025] To further optimize the above technical solution, the mass ratio of calcium aluminate to calcium silicate is 1:2, 2:1 or 1:1, and the amount of activator in the silica-alumina solid waste-based cementitious system is 1%-5% of the total mass of the silica-alumina solid waste-based cementitious material.

[0026] To further optimize the above technical solution, the auxiliary activator is sodium sulfate or potassium sulfate. The auxiliary activator can quickly dissolve and release sulfate ions, which react with calcium aluminate, calcium silicate and other components in the system to promote the rapid generation of ettringite early strength products. The dispersant is a polycarboxylate superplasticizer. The polycarboxylate superplasticizer disperses fine particles through steric hindrance and electrostatic repulsion, breaking the particle agglomeration.

[0027] To further optimize the above technical solution, each powder component in the activator is subjected to ultrafine grinding, resulting in a specific surface area ≥400m². 2 / kg.

[0028] A method for preparing the calcium aluminate-calcium silicate-based aluminosilicate solid waste activator as described above is provided, comprising the following steps: S1. Raw material drying: Dry the calcium aluminate, calcium silicate raw materials, and auxiliary activators, dispersants and additives at 105±5℃ to constant weight; S2. Powder grinding: The dried raw materials are ground separately using a planetary ball mill until the specific surface area is ≥400 m². 2 / kg, and then sieved through a 45μm sieve to remove coarse particles; S3. Dry powder mixing: The ground and sieved calcium aluminate and calcium silicate powders are mixed with the dry powder dispersant and auxiliary activator in a dry state using a V-type mixer or a high-efficiency dry powder mixer to ensure that the components are mixed evenly. S4. Screening and Packaging: Pass the uniformly mixed dry powder product through a 325-mesh sieve. After passing the screening, package the product to obtain dry powder calcium aluminate-calcium silicate-based silica-alumina solid waste activator.

[0029] An application of the calcium aluminate-calcium silicate-based silicoaluminate solid waste activator described above is provided. The activator is applied to concrete or mortar systems in which silicoaluminate solid waste is used as a cementing material. The mix proportion of the silicoaluminate solid waste-based cementing material is as follows by mass percentage: cement 40%, slag 10%, fly ash 20%, metakaolin 20%, silica fume 10%, water-cement ratio 0.4, and mortar-cement ratio 0.3. The dosage of the activator is 1%-5% of the total mass of the silicoaluminate solid waste-based cementing material. During construction, a dry-mixing followed by wet-mixing process is adopted, and it is used in conjunction with a polycarboxylate superplasticizer.

[0030] To further optimize the above technical solutions, the activator is classified into single-component and multi-component types according to its component type; the single-component type contains only calcium aluminate component and is suitable for construction occasions that require ultra-high strength within 1 day or 12 hours; the multi-component type contains calcium aluminate and calcium silicate components and is suitable for construction occasions that need to take into account early strength performance, later strength growth and durability.

[0031] To further optimize the above technical solution, the specific operating steps during construction are as follows: Step 1: Determine the dosage of activator according to the performance requirements of mortar. Take the corresponding dosage of activator and mix it with one-third of the total water volume for mortar mixing. Use a mechanical mixer to stir for 2-4 minutes until the mixture is uniform to obtain the activator solution. Step 2: Pour the dry powder components of the mortar into the mixer, add the activator solution, then add the remaining water and sand in sequence, and use a mechanical mixer to mix until the mortar is evenly mixed; Step 3: Quickly pour, plaster, or grout the well-mixed mortar.

[0032] To more clearly and in detail introduce the calcium aluminate-calcium silicate-based silica-alumina solid waste activator, its preparation method, and its application provided in the embodiments of the present invention, the following description will be based on specific embodiments.

[0033] Example 1 The calcium aluminate-calcium silicate-based silicoaluminate solid waste activator contains, by mass, 20 parts calcium aluminate and 20 parts calcium silicate in a mass ratio of 1:1, 3 parts sodium sulfate as an auxiliary activator, and 1 part polycarboxylate superplasticizer as a dispersant. In the preparation process, each raw material was first dried to constant weight at 105±5℃ for 4 hours, with a moisture content ≤0.5%. Then, it was ground separately using a planetary ball mill. After grinding, the powder was sieved through a 45μm sieve, and the specific surface area of ​​the powder reached 420m². 2 / kg; then each powder was poured into a V-type mixer and mixed at 200r / min for 30min. After being mixed evenly, it was passed through a 325-mesh sieve and vacuum-packed to obtain a dry powder activator.

[0034] When applied, the silica-alumina solid waste-based cementitious material is composed of 40% cement, 10% slag, 20% fly ash, 20% metakaolin, and 10% silica fume by mass percentage, with a water-cement ratio of 0.4 and a mortar-cement ratio of 0.3. The activator dosage is 3% of the total mass of the cementitious material (compound type).

[0035] The construction adopts the "dry mixing followed by wet mixing" process. First, the activator is mixed with 1 / 3 of the total water to make an activator solution. Then, the dry powder components of the cementitious material, sand and activator solution are mixed. After adding the remaining water, the mixture is stirred for 5 minutes. After being poured into shape, it is placed in a standard curing box for curing.

[0036] Performance test results show that the mortar has a 1-day compressive strength of 22.5 MPa and a flexural strength of 4.2 MPa, a 3-day compressive strength of 31.8 MPa and a flexural strength of 5.5 MPa, a 28-day compressive strength of 52.3 MPa and a flexural strength of 7.8 MPa, an initial setting time of 185 min, a final setting time of 260 min, no efflorescence on the surface within 7 days, and a 28-day drying shrinkage rate of 0.035%, exhibiting excellent early strength performance, workability, and volume stability.

[0037] Example 2 The activator for calcium aluminate-calcium silicate-based silica-alumina solid waste consists of 15 parts calcium aluminate and 30 parts calcium silicate by mass ratio of 1:2, 2 parts sodium sulfate, and 0.8 parts polycarboxylate superplasticizer.

[0038] The preparation process was slightly adjusted based on Example 1, with calcium aluminate and calcium silicate being ground to achieve a powder specific surface area of ​​435 m². 2 / kg, the remaining steps are the same as in Example 1.

[0039] When applying, the activator dosage is adjusted to 2% of the total mass of the cementitious materials (multi-admixture type), and the mix proportions, construction techniques and curing conditions of the remaining cementitious materials are the same as in Example 1.

[0040] Test results show that the mortar has a 1-day compressive strength of 19.8 MPa and a flexural strength of 3.8 MPa, a 3-day compressive strength of 30.2 MPa and a flexural strength of 5.2 MPa, a 28-day compressive strength of 55.6 MPa and a flexural strength of 8.1 MPa, an initial setting time of 195 min, a final setting time of 275 min, no efflorescence within 7 days, and a 28-day drying shrinkage rate of 0.032%, indicating better later-stage strength and volume stability.

[0041] Example 3 Potassium sulfate was selected as an auxiliary activator. The activator, by mass, consisted of 30 parts calcium aluminate, 15 parts calcium silicate (mass ratio of the two to 2:1), 4 parts potassium sulfate, and 1.5 parts polycarboxylate superplasticizer.

[0042] During preparation, calcium aluminate and calcium silicate are ground into powder, resulting in a powder specific surface area of ​​410 m². 2 / kg, and the remaining preparation steps are the same as in Example 1; When applying, the activator dosage is 4% of the total mass of the cementitious material (multi-admixture type). It is suitable for construction occasions requiring ultra-high strength within 1 day. The cementitious material mix ratio, construction process and curing conditions are the same as in Example 1.

[0043] The performance test results are as follows: 1-day compressive strength 25.3 MPa, flexural strength 4.5 MPa; 3-day compressive strength 33.5 MPa, flexural strength 5.8 MPa; 28-day compressive strength 53.8 MPa, flexural strength 7.9 MPa; initial setting time 170 min; final setting time 245 min; no efflorescence within 7 days; and 28-day shrinkage rate 0.038%. The early strength performance is outstanding, while also taking into account later strength and durability, which confirms the adaptability of different component ratios to performance.

[0044] Comparison Group 1 As a blank group, without the addition of any activator, the test results showed that its 1-day compressive strength was only 8.2 MPa, flexural strength was 1.5 MPa, 3-day compressive strength was 15.6 MPa, flexural strength was 2.8 MPa, 28-day compressive strength was 32.5 MPa, flexural strength was 5.2 MPa, initial setting time was 240 min, final setting time was 330 min, and 28-day drying shrinkage was 0.045%. Its strength performance and construction efficiency were far lower than those of Example 1.

[0045] Comparison Group 2 The single-doped calcium aluminate group contained only 30 parts of calcium aluminate (dosage 3%) as the activator, without calcium silicate, auxiliary activator and dispersant. The rest of the preparation steps and applications were the same as in Example 1. Although the 1-day compressive strength reached 20.1 MPa and the flexural strength was 3.9 MPa, showing good early strength performance, the 28-day compressive strength was only 38.6 MPa and the flexural strength was 6.1 MPa. The 28-day shrinkage rate was 0.052%, indicating slow strength growth and poor volume stability in the later stage.

[0046] Comparison Group 3 The single-doped calcium silicate group contains only 30 parts of calcium silicate (dosage 3%) as the activator, with no other components. The remaining preparation steps and applications are the same as in Example 1. Its 1-day compressive strength is 10.5 MPa, flexural strength is 2.0 MPa, 3-day compressive strength is 18.8 MPa, and flexural strength is 3.2 MPa. The early strength performance is weak. Although the 28-day compressive strength reaches 40.2 MPa, the overall performance is unbalanced.

[0047] Comparison Group 4 Using an existing strong alkali activator (water glass, modulus 3.2, dosage 3%), the remaining preparation steps and applications are the same as in Example 1. Its 1-day compressive strength is 18.5 MPa, flexural strength is 3.5 MPa, 3-day compressive strength is 27.6 MPa, flexural strength is 4.9 MPa, and 28-day compressive strength is 45.3 MPa, flexural strength is 7.0 MPa. Although the strength is better than the blank group, the initial setting time is only 120 min and the final setting time is 190 min. The excessively rapid setting leads to poor workability, and obvious efflorescence appears on the surface within 7 days. The 28-day shrinkage rate is 0.065%, and the volume stability is poor. Compared with the embodiment of the present invention, there are obvious technical defects.

[0048] Based on the test results of the above embodiments and comparative groups, it can be seen that the activator prepared by the present invention, through precise control of the ratio of calcium aluminate to calcium silicate (1:2, 1:1, 2:1), combined with sodium sulfate or potassium sulfate as an auxiliary activator and polycarboxylate dispersant, and combined with a refined preparation process, can fully activate the solid waste activity through the synergistic effect of the components when applied to the silica-alumina solid waste-based cementitious material system. This ensures both early strength and workability, while also improving later strength and durability. It effectively avoids the problems of efflorescence, uncontrolled coagulation, poor volume stability, and limited performance of single components that exist in existing activation technologies. It takes into account both construction efficiency and structural service stability, and has significant technical advantages and industrial application value.

[0049] Therefore, this invention employs the aforementioned calcium aluminate-calcium silicate-based silicoaluminate solid waste activator, its preparation method, and its application. The calcium aluminate mineral in the activator can rapidly hydrate, significantly improving the early strength of the cementitious system. Simultaneously, its components can synergistically react with the active silicoaluminate components in the solid waste, optimizing the microstructure and thus continuously improving the activity index of the solid waste. Compared to traditional methods such as strong alkali activation, this mineral-based activation method can more stably and controllably stimulate the potential of solid waste and helps improve the long-term durability of materials, providing an innovative path for the high-value-added resource utilization of solid waste. The compounding system can optimize the composition and structure of hydration products, promoting the formation of a denser and more uniform microstructure, thereby reducing volume changes caused by water evaporation and chemical shrinkage during hardening, effectively inhibiting shrinkage and microcrack formation, and improving the long-term dimensional stability of the material. This accelerator does not contain harmful components such as chloride ions, completely eliminating the risk of steel corrosion introduced by admixtures. It is particularly suitable for reinforced concrete structures with strict corrosion resistance requirements, helping to extend the service life of the structure and improve its durability in harsh environments. By using bulk industrial solid waste as the main raw material, waste is treated at the source, which greatly reduces the cost of raw materials. At the same time, its preparation process does not require high temperature or complex chemical treatment, the process is simple and energy consumption is low, which further reduces the production cost.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A calcium aluminate-calcium silicate-based silicoaluminate solid waste activator, characterized in that, By mass, it contains the following components: 10-30 parts calcium aluminate, 10-30 parts calcium silicate, 1-5 parts auxiliary activator, and 0.5-2 parts dispersant.

2. The calcium aluminate-calcium silicate-based aluminosilicate solid waste activator according to claim 1, characterized in that, The mass ratio of calcium aluminate to calcium silicate is 1:2, 2:1 or 1:1, and the amount of activator in the silica-alumina solid waste-based cementitious system is 1%-5% of the total mass of the silica-alumina solid waste-based cementitious material.

3. The calcium aluminate-calcium silicate-based aluminosilicate solid waste activator according to claim 1, characterized in that, The auxiliary activator is sodium sulfate or potassium sulfate, and the dispersant is a polycarboxylate superplasticizer.

4. The calcium aluminate-calcium silicate-based aluminosilicate solid waste activator according to claim 1, characterized in that, Each powder component in the activator is subjected to ultrafine grinding, resulting in a specific surface area ≥400 m². 2 / kg.

5. A method for preparing a calcium aluminate-calcium silicate-based aluminosilicate solid waste activator as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Raw material drying: Dry the calcium aluminate, calcium silicate raw materials, and auxiliary activators, dispersants and additives at 105±5℃ to constant weight; S2. Powder grinding: The dried raw materials are ground separately using a planetary ball mill until the specific surface area is ≥400 m². 2 / kg, and then sieved through a 45μm sieve to remove coarse particles; S3. Dry powder mixing: The ground and sieved calcium aluminate and calcium silicate powders are mixed with the dry powder dispersant and auxiliary activator in a dry state using a V-type mixer or a high-efficiency dry powder mixer to ensure that the components are mixed evenly. S4. Screening and Packaging: Pass the uniformly mixed dry powder product through a 325-mesh sieve. After passing the screening, package the product to obtain dry powder calcium aluminate-calcium silicate-based silica-alumina solid waste activator.

6. The application of a calcium aluminate-calcium silicate-based aluminosilicate solid waste activator as described in any one of claims 1-4, characterized in that, The activator is applied to concrete or mortar systems using siliceous aluminate solid waste as a cementing material; the mix proportion of the siliceous aluminate solid waste-based cementitious material is as follows by mass percentage: cement 40%, slag 10%, fly ash 20%, metakaolin 20%, silica fume 10%, water-cement ratio 0.4, and mortar-cement ratio 0.3; the dosage of the activator is 1%-5% of the total mass of the siliceous aluminate solid waste-based cementitious material, and a dry-mixing followed by wet-mixing process is adopted during construction, and it is used in conjunction with polycarboxylate superplasticizer.

7. The application of the calcium aluminate-calcium silicate-based aluminosilicate solid waste activator according to claim 6, characterized in that, The activator is classified into single-component and multi-component types according to its component type; the single-component type contains only calcium aluminate component and is suitable for construction occasions requiring ultra-high strength within 1 day or 12 hours; the multi-component type contains calcium aluminate and calcium silicate components and is suitable for construction occasions that need to take into account early strength performance, later strength growth and durability.

8. The application of the calcium aluminate-calcium silicate-based aluminosilicate solid waste activator according to claim 6, characterized in that, The specific operating steps during construction are as follows: Step 1: Determine the dosage of activator according to the performance requirements of mortar. Take the corresponding dosage of activator and mix it with one-third of the total water volume for mortar mixing. Use a mechanical mixer to stir for 2-4 minutes until the mixture is uniform to obtain the activator solution. Step 2: Pour the dry powder components of the mortar into the mixer, add the activator solution, then add the remaining water and sand in sequence, and use a mechanical mixer to mix until the mortar is evenly mixed; Step 3: Quickly pour, plaster, or grout the well-mixed mortar.