Aluminum sulfate type liquid accelerator and preparation method thereof

Abstract

According to the aluminum sulfate type liquid accelerator and the preparation method thereof, the modified liquid aluminum sulfate added into the accelerator can rapidly react with cement clinker minerals and water to generate a large amount of ettringite-like substances, the ettringite-like substances are mutually overlapped to form a network, a hardened network structure is formed, meanwhile, a large amount of water is consumed, and the water content is reduced; rapid setting and hardening of the cement paste are promoted; the added aluminum fluoride can enable the slurry to be quickly coagulated and can also prevent the cement from being hydrated at an early stage; the added low-temperature-resistant additive is aluminum oxide composite silicon dioxide aerogel, a basic framework for accommodating dopants is provided, the influence of aluminum fluoride and modified aluminum sulfide on the growth of ettringite is added, water can be further consumed, slurry condensation is accelerated, and the influence on the condensation time of the low-temperature-resistant additive in a low-temperature environment is not large.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sewage treatment coagulant, in particular to a kind of liquid accelerator of aluminium sulfate type and its preparation method. BACKGROUND

[0002] Accelerator generally refers to concrete accelerator, which is an additive that can make concrete quickly coagulate and harden, and is an essential additive for shotcrete and other engineering. In recent years, due to the rapid development of national infrastructure and the continuous improvement of the public's environmental safety awareness, alkaline accelerator, as a main product for long-term application in shotcrete construction and engineering scenarios requiring rapid strength formation, such as tunnel support, mine roadway and other underground engineering. However, alkaline accelerator has limitations and risks, including significant loss of concrete long-term strength, significant risk of alkali-aggregate reaction: alkaline accelerator contains sodium aluminate, sodium carbonate and other substances with high alkali content, which may cause alkali-aggregate reaction, leading to reduced concrete durability and increased internal corrosion risk. Alkaline accelerator also has an impact on health and construction environment: alkaline accelerator releases irritating gases during use, which may harm the health of construction personnel over a long period of time. In addition, its high alkaline nature can easily lead to deterioration of the construction environment, requiring protective equipment. Therefore, the development trend of the market is to make liquid accelerator non-alkaline. Especially, aluminum sulfate type liquid accelerator is gradually replacing traditional alkaline products, as it has better environmental performance, higher 28-day compressive strength retention rate and no corrosiveness.

[0003] Compared with traditional alkaline accelerator, aluminum sulfate type liquid accelerator has the advantages of non-alkaline formula, low corrosiveness, no irritating dust, etc., and has the characteristics of environmental protection and use safety; in terms of performance, aluminum sulfate type liquid accelerator has the characteristics of high long-term strength retention rate and controllable setting time, and is suitable for ordinary concrete, high-strength concrete and self-compacting concrete, and has good compatibility with cement brands. Moreover, it has small strength loss and significantly reduces maintenance costs in the later period.

[0004] However, aluminum sulfate type liquid accelerator still has the following deficiencies: 1. Sulfate erosion risk: high dosage may cause internal sulfate erosion of concrete, and high sulfate content in accelerator will adversely affect the durability of concrete; if the dosage is low, it will affect the strength of concrete; 2. Temperature sensitivity: setting time may be prolonged in low temperature environment; 3. Stability requirements: high stability storage requirements, such as light protection and anti-settling, etc., and some products may have stratification phenomenon.

[0005] In summary, aluminum sulfate-based liquid accelerators are significantly superior to traditional alkaline accelerators in terms of environmental friendliness, durability, and construction safety. However, the risk of sulfate corrosion and temperature adaptability must be considered. With the advancement of the non-alkaliification trend, aluminum sulfate-based accelerators have become the preferred choice in tunneling, underground engineering, and other fields. We are continuously researching and exploring their performance. To this end, we disclose an aluminum sulfate-based liquid accelerator and its preparation method. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an aluminum sulfate-based liquid quick-setting agent to solve the problems described in the background art.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: An aluminum sulfate-based liquid quick-setting agent, with the following formula based on its mass components: Liquid aluminum sulfate 28-45 parts, aluminum fluoride 7-9 parts, aluminum hydroxide 10-17 parts, hydrofluoric acid 30-55 parts, solution conditioner 8-12 parts, modified aluminum sulfate 2-5 parts, triethanolamine 1.5-7 parts, low temperature resistant additive 2-9 parts, balance is water; The low-temperature resistant additive is an alumina-silica composite aerogel.

[0008] Based on the above scheme and as a preferred embodiment of the above scheme, the solution regulator is a solution pH regulator.

[0009] Based on the above scheme and as a preferred embodiment of the above scheme, the pH adjuster of the solution is sodium aluminate solution.

[0010] Based on the above scheme and as a preferred embodiment of the above scheme, the mass ratio of the liquid aluminum sulfate to the aluminum fluoride is (4.0-5.0):1.

[0011] Based on the above scheme and as a preferred embodiment of the above scheme, the mass ratio of aluminum hydroxide powder to hydrofluoric acid is 1:(3.7-3.9).

[0012] Based on the above scheme and as a preferred embodiment of the above scheme, the modified liquid aluminum sulfate is aluminum formate modified aluminum sulfate.

[0013] Based on the above scheme and as a preferred embodiment of the above scheme, the alumina composite silica aerogel is prepared by the sol-gel method.

[0014] Based on the above scheme and as a preferred embodiment of the above scheme, a method for preparing an aluminum sulfate-type liquid quick-setting agent includes the following steps: S1. Raw material preparation First, alumina composite silica aerogel was prepared by sol-gel method and dried at 60°C for later use, which is the low-temperature resistant additive mentioned above. Simultaneously, formic acid and aluminum hydroxide are added to a beaker at a molar ratio of 3.5:1. The mixture is heated to 60°C and reacted for 2.5-3.5 hours. Then, aluminum sulfate is added and stirred until completely dissolved. Next, fluorosilicic acid, triethanolamine, and lithium carbonate are added. The mixture is heated to 78-82°C and reacted for 0.5-1 hour. After rapid cooling, the modified liquid aluminum sulfate is obtained and set aside for later use. S2, Material Premixing First, add water to the PPH reactor, then add the modified aluminum sulfate and the hydrofluoric acid to the PPH reactor according to the mass ratio, turn on the agitator and the tail gas absorption device, and stir for 10-15 minutes to obtain pre-stirred material A; Meanwhile, the liquid aluminum sulfate and the aluminum fluoride were stirred and mixed in a container according to the mass ratio to obtain pre-stirred material B; S3, Preparation of Mixed Solution Maintain the stirring speed of the PPH reactor, and then add aluminum hydroxide powder, pre-stirred material B, triethanolamine and low temperature resistant additive to pre-stirred material A in sequence. Stir at the same stirring speed for 30-40 minutes until the mixture is clear and transparent to obtain a mixed solution. S4, Preparation of Accelerating Agent Heat the mixed solution to 80°C, add the solution conditioner solution dropwise, adjust the pH value to above 2, and stir for 10-15 minutes until clear and transparent; S5, Preparation of Accelerating Agent Adjust the temperature to room temperature and continue stirring until the solution temperature drops to room temperature to obtain aluminum sulfate type liquid quick-setting agent, which is then bottled and sealed for later use.

[0015] Based on the above scheme and as a preferred embodiment of the above scheme, the stirring speed is 300-400 rpm.

[0016] Compared with the prior art, the beneficial effects of the technical solution of the present invention are: This invention provides an aluminum sulfate-based liquid accelerator and its preparation method. The modified liquid aluminum sulfate added to the accelerator can react rapidly with cement clinker minerals and water to generate a large amount of ettringite-like substances. These substances interlock to form a network, and while forming a hardened network structure, they consume a large amount of water, promoting rapid setting and hardening of the cement paste. The added aluminum fluoride enables the paste to set rapidly and also inhibits early cement hydration. The added low-temperature resistant additive is an alumina composite silica aerogel, which provides a basic framework for the containment of dopants. In addition, the influence of aluminum fluoride and modified aluminum sulfide on the growth of ettringite further consumes water and accelerates the setting of the paste, and its setting time is not significantly affected at low temperatures. Detailed Implementation

[0017] To enable those skilled in the art to better understand the technical solutions of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific examples, but these should not be construed as limiting the present patent.

[0018] Unless otherwise specified, the test methods or experimental methods described in the following examples / comparative examples are conventional methods; unless otherwise specified, the reagents and materials are obtained from conventional commercial sources or prepared by conventional methods.

[0019] In this invention, the modified liquid aluminum sulfate is aluminum formate-modified aluminum sulfate. Specifically, formic acid and aluminum hydroxide are added to a beaker in a molar ratio of 3.5:1, and the mixture is heated to 60°C and reacted for 2.5-3.5 hours to obtain an aluminum formate solution. Then, aluminum sulfate is added to the aluminum formate solution and stirred until completely dissolved. Next, fluorosilicic acid, triethanolamine, and lithium carbonate are added sequentially, and the mixture is heated to 78-82°C and reacted for 0.5-1 hour, followed by rapid cooling to obtain the modified liquid aluminum sulfate. The amount of aluminum formate solution added is 1.5-2.5% of the weight of aluminum sulfate. The modified liquid aluminum sulfate described herein uses aluminum sulfate as the main material. Aluminum sulfate provides a large amount of aluminum ions and sulfate ions, which can rapidly react with calcium ions and hydroxide ions in cement clinker minerals, as well as water in the system, to generate a large amount of ettringite-like substances. These substances have an interlocking effect, forming a hardened network structure around cement particles while consuming a large amount of water, thus promoting rapid setting and hardening of the cement paste, building early strength, and improving the strength of cement mortar. The modified liquid aluminum sulfate is doped with aluminum formate, which increases the concentration of aluminum ions in the modified liquid aluminum sulfate component, thereby accelerating the rapid setting effect. Moreover, during the cement hydration reaction, the interlocking effect of the ettringite-like substances continuously accumulates to form a network state, further promoting the rapid setting effect. However, the amount of aluminum formate doped should not be too high. If it is too high, the acidity of the modified liquid aluminum sulfate component will increase, the setting-promoting effect of the accelerator will gradually weaken, and the setting time of the cement mortar will be affected.

[0020] Furthermore, the aluminum sulfate-based liquid accelerator system of the present invention contains aluminum fluoride. Specifically, the mass ratio of the liquid aluminum sulfate to the aluminum fluoride is (4.0-5.0):1, preferably 4.5:1. Aluminum fluoride is a fluorine-aluminum complex. Similarly, in the aluminum sulfate-based accelerator, the addition of aluminum fluoride increases the aluminum ion concentration in the system, resulting in a significant accelerating effect. Moreover, aluminum fluoride and modified liquid aluminum sulfate are dispersed and interwoven in the gaps between cement mortar particles, forming a tightly overlapping network structure, thereby accelerating the setting and hardening rate of the cement paste and improving the compressive strength of the mortar. The aluminum fluoride described in this invention is commercially available, industrial grade.

[0021] Furthermore, the mass ratio of aluminum hydroxide powder to hydrofluoric acid is 1:(3.7-3.9). Preferably, the mass ratio of aluminum hydroxide powder to hydrofluoric acid in this invention is 1:3.8.

[0022] Furthermore, the alumina-silica composite aerogel is prepared via a sol-gel method. Specifically, it uses aluminum sol as the aluminum source, tetraethyl orthosilicate, and alkaline silica sol as the composite silicon source, and includes the following steps: 1. Preparation of the first mixture Tetraethyl orthosilicate, water, and ethanol were dissolved in the alcohol-water mixture at room temperature in a molar ratio of 1:2:9. Then, 0.5M hydrochloric acid was added to adjust the pH to 2-3. The mixture was stirred until the tetraethyl orthosilicate was completely dissolved, and stirring continued for 15-25 minutes. Aluminum sol was then added, and stirring continued for 10-15 minutes to obtain the first mixture. The molar ratio of aluminum to silicon in the first mixture is (0.05-0.35):1.

[0023] 2. Mixing of alkaline silica sol with the first mixture The alkaline silica sol was diluted with an alcohol-water mixture at a molar ratio of 1:5:1 to obtain a second mixture. This second mixture was then added to the first mixture and stirred for 5-10 minutes to obtain a homogeneous mixture. The mixture was then transferred to a polyethylene mold and gelled under normal pressure to obtain a preliminary aerogel. The gelation conditions were aging at 45°C for 10-12 hours.

[0024] 3. Preparation of alumina-silica composite aerogel The preliminary aerogel was immersed in a solution of ethanol and tetraethyl orthosilicate in a 4:1 ratio for 24 hours to enhance its structure. Then, the preliminary aerogel was immersed in hexane for solvent exchange, with the hexane being replaced every 12 hours at room temperature, for at least two replacements. Subsequently, the aerogel was placed in a solution of graphene oxide and hexane in a 1:9 volume ratio for 24 hours for surface modification, thus obtaining an alumina-silica composite aerogel.

[0025] Graphene oxide possesses abundant functional groups and exhibits amphiphilicity. The interaction between graphene oxide and Si-OH groups improves the hydrophilicity and hydrophobicity of the gel. However, unreacted graphene oxide and HCl generated by the graphene oxide-water interaction remain within the gel pores. To remove these residual components, the gel was washed 2-3 times with n-hexane. Finally, the gel was dried at 60°C for 8-12 hours to obtain an alumina-silica composite aerogel.

[0026] The tetraethyl orthosilicate, ethanol, and n-hexane were all analytical grade and purchased from Aladdin Reagent Co., Ltd.; the alkaline silica sol was purchased from Guolian Technology Co., Ltd., with a pH of 9.9, a solid content of 28.1%, and a particle size of 11-13 nm; the aluminum sol was purchased from Hangzhou Jiupeng New Materials Co., Ltd., with a pH of 4.3, a solid content of 18.9%, and a particle size of 8-10 nm; and the graphene oxide was purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., with a solid content of 3.5%.

[0027] Example 1 An aluminum sulfate-based liquid quick-setting agent, with the following formula based on its mass components: The mixture consists of 36 parts liquid aluminum sulfate, 8 parts aluminum fluoride, 10 parts aluminum hydroxide, 38 parts hydrofluoric acid, 10 parts solution conditioner, 3 parts modified aluminum sulfate, 5 parts triethanolamine, 6 parts low-temperature resistant additive, and the remainder is water. The low-temperature resistant additive is an alumina-silica composite aerogel.

[0028] Furthermore, the solution adjuster is a solution pH adjuster. Preferably, the solution pH adjuster is a sodium aluminate solution.

[0029] Furthermore, the modified liquid aluminum sulfate is aluminum formate-modified aluminum sulfate.

[0030] Furthermore, the alumina-silica composite aerogel is prepared by the sol-gel method.

[0031] Furthermore, the preparation method of the aluminum sulfate-based liquid quick-setting agent includes the following steps: S1. Raw material preparation First, alumina-silica composite aerogel was prepared by the sol-gel method for later use. Simultaneously, the modified liquid aluminum sulfate is prepared for later use; S2, Material Premixing First, add water to the PPH reactor, then add the modified aluminum sulfate and the hydrofluoric acid to the PPH reactor according to the mass ratio, turn on the agitator and the tail gas absorption device, and stir for 10-15 minutes to obtain pre-stirred material A; Meanwhile, the liquid aluminum sulfate and the aluminum fluoride were stirred and mixed in a container according to the mass ratio to obtain pre-stirred material B; S3, Preparation of Mixed Solution Maintain the stirring speed of the PPH reactor, and then add aluminum hydroxide powder, pre-stirred material B, triethanolamine and low temperature resistant additive to pre-stirred material A in sequence. Stir at the same stirring speed for 30-40 minutes until the mixture is clear and transparent to obtain a mixed solution. S4, Preparation of Accelerating Agent Heat the mixed solution to 80°C, add the solution conditioner solution dropwise, adjust the pH value to above 2, and stir for 10-15 minutes until clear and transparent; S5, Preparation of Accelerating Agent Adjust the temperature to room temperature and continue stirring until the solution temperature drops to room temperature to obtain aluminum sulfate type liquid quick-setting agent, which is then bottled and sealed for later use.

[0032] Furthermore, the stirring speed is 350 rpm.

[0033] Example 2 Unlike Example 1 above, an aluminum sulfate-based liquid quick-setting agent has the following formulation by weight of its components: The mixture consists of 45 parts liquid aluminum sulfate, 9 parts aluminum fluoride, 10 parts aluminum hydroxide, 39 parts hydrofluoric acid, 12 parts solution conditioner, 5 parts modified aluminum sulfate, 7 parts triethanolamine, 9 parts low-temperature resistant additive, and the remainder is water. Other operations are the same as in Example 1.

[0034] Example 3 Unlike Example 1 above, an aluminum sulfate-based liquid quick-setting agent has the following formulation by weight of its components: The mixture consists of 28 parts liquid aluminum sulfate, 7 parts aluminum fluoride, 10 parts aluminum hydroxide, 38 parts hydrofluoric acid, 8 parts solution conditioner, 2 parts modified aluminum sulfate, 1.5 parts triethanolamine, 2 parts low-temperature resistant additive, and the remainder is water. Other operations are the same as in Example 1.

[0035] Comparative Example 1 Unlike Example 1, the modified aluminum sulfate is replaced with an equal mass of liquid aluminum sulfate. That is, the aluminum sulfate-based liquid quick-setting agent formulation does not contain modified aluminum sulfate.

[0036] Other operations are the same as in Example 1.

[0037] Comparative Example 2 Unlike Example 1, the aluminum sulfate-based liquid quick-setting agent formulation does not contain aluminum fluoride.

[0038] Other operations are the same as in Example 1.

[0039] Comparative Example 3 Unlike Example 1, the low-temperature resistant additive was replaced with an equal mass of commercially available industrial-grade alumina.

[0040] Other operations are the same as in Example 1.

[0041] Comparative Example 4 Unlike Example 1, the low-temperature resistant additive was replaced with silicon dioxide of the same mass and size.

[0042] Other operations are the same as in Example 1.

[0043] Comparative Example 5 Unlike Example 1, alumina and silicon dioxide were physically mixed according to the same molar ratio of aluminum to silicon, and then added according to the proportion of the aluminum sulfate-type liquid quick-setting agent to prepare the quick-setting agent. Other operations were the same as in Example 1.

[0044] Comparative Example 6 Unlike Example 1, the aluminum sulfate-based liquid quick-setting agent formulation does not contain low-temperature resistant additives.

[0045] Other operations are the same as in Example 1.

[0046] Comparative Example 7 Unlike Example 1, the aluminum sulfate-based liquid quick-setting agent formulation does not contain aluminum fluoride or modified aluminum sulfate.

[0047] Other operations are the same as in Example 1.

[0048] Comparative Example 8 Unlike Example 1, the aluminum sulfate-based liquid quick-setting agent formulation does not contain modified aluminum sulfate or low-temperature resistant additives.

[0049] Other operations are the same as in Example 1.

[0050] Comparative Example 9 Unlike Example 1, the aluminum sulfate-based liquid quick-setting agent formulation does not contain aluminum fluoride or low-temperature resistant additives.

[0051] Other operations are the same as in Example 1.

[0052] Performance testing Sample performance testing mainly includes the following aspects: 1. Setting time Weigh out a certain mass of PI 42.5 cement (the reference cement specified in "Concrete Admixtures GB8076—2008"), and use ISO standard sand produced by Xiamen Aisiou Standard Sand Co., Ltd. After adding aluminum sulfate-based alkali-free liquid accelerator at a certain mass ratio, test the setting time of the cement paste according to "Accelerators for Shotcrete" (GB / T35159—2017), including initial setting time and final setting time. The accelerator dosage is 8% of the cement mass. This standard requires that the initial setting time of the cement paste be ≤5 min and the final setting time be ≤12 min.

[0053] 2. Compressive strength The mortar compressive strength test was conducted according to the method specified in "Accelerating Agent for Shotcrete" (GB / T 35159—2017). The specimen size was 40mm×40mm×160mm, and the accelerating agent dosage was 8% of the cement mass. The compressive strength included 1-day compressive strength and 28-day compressive strength. The standard requires that the mortar 1-day compressive strength ≥ 7.0MPa and the 28-day compressive strength ratio ≥ 90%.

[0054] 3. Stability Test Stability testing mainly refers to the stable storage time, specifically the number of days after the accelerator first crystallizes. If the stable storage time is >30 days, it is recorded as 30 days.

[0055] 4. Low-temperature condensation time To further test the setting stability of the cement slurry in a low-temperature environment, we mixed the material in a stainless steel drum in an ice-water bath and tested the setting time of the material.

[0056] Based on the above testing methods and standards, we tested each sample, and the test results are compared in Table 1 below.

[0057] Table 1 Comparison of Relevant Performance Tests The analysis in the table above shows that, in terms of compressive strength comparison, both aluminum sulfate and aluminum fluoride have a certain reinforcing effect on accelerators, and the reinforcing effect of aluminum fluoride (Comparative Example 8) is significantly better than that of modified aluminum sulfate (Comparative Example 9). It should be noted that while the accelerator effect of aluminum fluoride is significant, the 1-day compressive strength of the cement mortar after its addition is not high. This is because the reaction of aluminum fluoride with cement accelerates the formation of ettringite, causing the mortar to set rapidly, while simultaneously generating fluoride-containing hydration products that hinder early cement hydration.

[0058] The modified liquid aluminum sulfate added to the accelerator of this invention can react rapidly with cement clinker minerals and water to generate a large amount of ettringite-like substances. These substances interlock to form a network, and while forming a hardened network structure, they consume a large amount of water, promoting rapid setting and hardening of the cement paste. The added aluminum fluoride enables the paste to set rapidly and also inhibits early cement hydration. The added low-temperature resistant additive is an alumina composite silica aerogel, which provides a basic framework for containing dopants. Furthermore, the influence of aluminum fluoride and modified aluminum sulfide on the growth of ettringite further consumes water and accelerates paste setting, with minimal impact on setting time at low temperatures. Although the setting time is slightly prolonged at low temperatures, it remains within the standard range.

[0059] Further testing revealed that the aluminum sulfate-based accelerator used in this invention exhibits a high retention rate of later-stage strength, with a 28-day compressive strength ratio exceeding 90%. Furthermore, the combined use of aluminum fluoride and modified aluminum sulfate makes its application even more convenient. Moreover, the setting time is controllable after adding the accelerator: the initial setting time can be controlled within 1-3 minutes, and the final setting time within 5-10 minutes, meeting the demands of rapid construction and facilitating further promotion and application.

[0061] Unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" in this invention should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An aluminum sulfate-based liquid quick-setting agent, characterized in that, Based on the components by weight, its formula is as follows: Liquid aluminum sulfate 28-45 parts, aluminum fluoride 7-9 parts, aluminum hydroxide 10-17 parts, hydrofluoric acid 30-55 parts, solution conditioner 8-12 parts, modified aluminum sulfate 2-5 parts, triethanolamine 1.5-7 parts, low temperature resistant additive 2-9 parts, balance is water; The low-temperature resistant additive is an alumina-silica composite aerogel.

2. The aluminum sulfate-based liquid quick-setting agent according to claim 1, characterized in that, The solution regulator is a solution pH regulator.

3. The aluminum sulfate-based liquid quick-setting agent according to claim 2, characterized in that, The pH adjuster for the solution is sodium aluminate solution.

4. The aluminum sulfate-based liquid quick-setting agent according to claim 1, characterized in that, The mass ratio of the liquid aluminum sulfate to the aluminum fluoride is (4.0-5.0):

1.

5. The aluminum sulfate-based liquid quick-setting agent according to claim 1, characterized in that, The mass ratio of aluminum hydroxide powder to hydrofluoric acid is 1:(3.7-3.9).

6. The aluminum sulfate-based liquid quick-setting agent according to claim 1, characterized in that, The modified liquid aluminum sulfate is aluminum formate-modified aluminum sulfate.

7. The aluminum sulfate-based liquid quick-setting agent according to claim 1, characterized in that, The alumina-silica composite aerogel was prepared by the sol-gel method.

8. A method for preparing an aluminum sulfate-type liquid quick-setting agent according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Raw material preparation First, alumina composite silica aerogel was prepared by sol-gel method and dried at 60°C for later use, which is the low-temperature resistant additive mentioned above. Simultaneously, formic acid and aluminum hydroxide are added to a beaker at a molar ratio of 3.5:

1. The mixture is heated to 60°C and reacted for 2.5-3.5 hours. Then, aluminum sulfate is added and stirred until completely dissolved. Next, fluorosilicic acid, triethanolamine, and lithium carbonate are added. The mixture is heated to 78-82°C and reacted for 0.5-1 hour. After rapid cooling, the modified liquid aluminum sulfate is obtained and set aside for later use. S2, Material Premixing First, add water to the PPH reactor, then add the modified aluminum sulfate and the hydrofluoric acid to the PPH reactor according to the mass ratio, turn on the agitator and the tail gas absorption device, and stir for 10-15 minutes to obtain pre-stirred material A; Meanwhile, the liquid aluminum sulfate and the aluminum fluoride were stirred and mixed in a container according to the mass ratio to obtain pre-stirred material B; S3, Preparation of Mixed Solution Maintain the stirring speed of the PPH reactor, and then add aluminum hydroxide powder, pre-stirred material B, triethanolamine and low temperature resistant additive to pre-stirred material A in sequence. Stir at the same stirring speed for 30-40 minutes until the mixture is clear and transparent to obtain a mixed solution. S4, Preparation of Accelerating Agent Heat the mixed solution to 80°C, add the solution conditioner solution dropwise, adjust the pH value to above 2, and stir for 10-15 minutes until clear and transparent; S5, Preparation of Accelerating Agent Adjust the temperature to room temperature and continue stirring until the solution temperature drops to room temperature to obtain aluminum sulfate type liquid quick-setting agent, which is then bottled and sealed for later use.

9. The method for preparing an aluminum sulfate-based liquid quick-setting agent according to claim 8, characterized in that, The stirring speed is 300-400 rpm.

Images