Emulsion type alkali-free accelerator and preparation method thereof

Abstract

The invention relates to the technical field of concrete admixture accelerators, in particular to an emulsion type alkali-free accelerator and a preparation method thereof.The emulsion type alkali-free accelerator is prepared from, by weight, 50-75 parts of coagulation accelerating component, 5-15 parts of fluosilicate, 15-25 parts of aluminum formate modified aluminum sulfate, 6-12 parts of complexing component, 8-15 parts of early strength component, 2-4 parts of suspension component, 1-3 parts of pH adjusting component and 0.5-1 part of anti-caking component; and 6-10 parts of a modified polyacrylic acid polymer. The early-strength liquid alkali-free setting accelerator has excellent setting effect and good product stability, can be compounded with an early-strength component to obtain the early-strength liquid alkali-free setting accelerator, can give consideration to both product stability and early strength performance, and is good in early strength and not prone to precipitation.

Description

Technical Field

[0001] The invention relates to the technical field of concrete admixture type accelerating setting agent, and more specifically, to an emulsion type alkali-free accelerating setting agent and a preparation method thereof. Background Art

[0002] Alkali-free liquid accelerator can significantly reduce the dust content in the construction environment, and has the advantages of safe and environmentally friendly production and use, fast setting and hardening, high strength guarantee rate, and no alkali aggregate hazards. It is widely used in shotcrete. Aluminum phase materials can promote the formation of calcium sulfonate and shorten the setting and hardening process of cement-based materials. They are the core materials of alkali-free accelerators, such as aluminum sulfate 18hydrate. However, the solubility of conventional aluminum sulfate 18hydrate is low. In order to improve the setting and hardening effect of the accelerator, using polyaluminum sulfate to increase the aluminum phase content is one of the most effective ways.

[0003] Patent CN202410313652.4 discloses a powdered alkali-free quick-setting agent and a preparation method thereof, wherein the main preparation method is to weigh magnesium aluminum hydrotalcite, aluminum sulfate, calcium silicate hydrate, early strength component, water retention component, accelerating coagulant component and water absorption component in parts by weight and mix them evenly. This technical solution is easy to operate, but the powdered quick-setting agent contains a large amount of water-insoluble substances, and its water solubility is poor during use, and there are many problems in terms of performance and stability.

[0004] Patent CN202211004195.8 discloses a method for preparing a dry powder accelerating setting agent using fluorosilicone slag. The main technical scheme of the patent is that, by weight, it contains 1-5 parts of fluorosilicone slag, 0.5-2 parts of sodium salt, 1-4 parts of aluminum-containing components, 40-55 parts of aluminum sulfate and 35-55 parts of water. First, the solution is wet-milled to obtain different mother liquors, and then the mother liquor and aluminum sulfate solution are mixed for reaction, and finally the water is dried and pulverized to obtain the dry powder accelerating setting agent. A large amount of energy will be consumed when the water is dried, which greatly increases the energy cost.

[0005] However, the raw materials of the commonly used alkali-free liquid accelerators are generally aluminum compounds. Aluminum ions are very likely to undergo hydrolysis-polymerization-precipitation reactions in water, and the solubility of aluminum salts is relatively low. As time goes by, the alkali-free liquid accelerators are prone to unstable phenomena such as flocculation, precipitation, and crystallization. The current alkali-free liquid accelerators have problems such as low early 1d strength, later strength loss, poor stability, easy precipitation, and long setting time. Summary of the invention

[0006] The present invention provides an emulsion-type alkali-free quick-setting agent and a preparation method thereof, which have excellent quick-setting effect and good product stability, and can be compounded with an early-strength component to obtain an early-strength liquid alkali-free quick-setting agent, which can take into account both product stability and early-strength performance, has good early strength, and is not easy to precipitate.

[0007] In a first aspect, the present invention provides an emulsion-type alkali-free quick-setting agent, wherein the raw materials include by weight: 50 to 75 parts of a coagulant component, 5 to 15 parts of a fluorosilicate, 15 to 25 parts of aluminum formate-modified aluminum sulfate, 6 to 12 parts of a complexing component, 8 to 15 parts of an early strength component, 2 to 4 parts of a suspending component, 1 to 3 parts of a pH adjusting component, 0.5 to 1 part of an anti-caking component, and 6 to 10 parts of a modified polyacrylic acid polymer.

[0008] Preferably, the raw materials include by weight: 62 to 75 parts of accelerating coagulant component, 8 to 15 parts of fluorosilicate, 15 to 20 parts of aluminum formate modified aluminum sulfate, 8 to 10 parts of complexing component, 10 to 15 parts of early strength component, 3 to 4 parts of suspension component, 2 to 3 parts of pH adjusting component, 0.7 to 1 part of anti-caking component, and 8 to 10 parts of modified polyacrylic acid polymer.

[0009] Preferably, the raw materials include by weight: 66 parts of accelerating coagulant component, 12 parts of fluorosilicate, 21 parts of aluminum formate modified aluminum sulfate, 8 parts of complexing component, 11 parts of early strength component, 4 parts of suspending component, 2 parts of pH adjusting component, 1 part of anti-caking component, and 8 parts of modified polyacrylic acid polymer.

[0010] Preferably, the coagulant-accelerating component is one of aluminum sulfate 18hydrate, nano-hydrated calcium silicate, silica powder, silicon carbon, and glass powder.

[0011] Preferably, the fluorosilicate is one of magnesium fluorosilicate, zinc fluorosilicate, sodium fluorosilicate, potassium fluorosilicate and hexafluorosilicate.

[0012] Preferably, the method for preparing aluminum formate-modified aluminum sulfate comprises the following steps:

[0013] S1: Add formic acid and aluminum hydroxide in a molar ratio of (1-4):1 into a beaker, heat to 60-80°C, react for 2-3 hours, and freeze-dry to obtain aluminum formate powder;

[0014] S2: Add water to a polytetrafluoroethylene beaker, heat to 60-80°C, add aluminum sulfate, stir until completely dissolved, add 1%-4% by mass of the aluminum formate obtained in step S1, then add fluorosilicic acid, triethanolamine, and lithium carbonate in sequence, heat the mixed solution to 80-100°C, react for 1-2h, and then quickly cool to obtain aluminum formate-modified aluminum sulfate.

[0015] Preferably, the complexing components are lysine, phosphoric acid and ethylenediaminetetraacetic acid, and the mass ratio of lysine, phosphoric acid and ethylenediaminetetraacetic acid is 1-2:1-4:1-3.

[0016] Preferably, the early strength component is one or more of diethanolamine, hydrated aluminum sulfate, and solid alcoholamine.

[0017] Preferably, the modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin for coordination.

[0018] Preferably, the suspension component is one of lignin sulfonate, naphthalene sulfonate, formaldehyde condensate, magnesium aluminum silicate, quartz, feldspar and carbonate; the pH adjusting component is one or more of citric acid, anhydrous sodium hydroxide, anhydrous calcium hydroxide and anhydrous calcium carbonate.

[0019] Preferably, the anti-caking component is one or more of microcrystalline cellulose, calcium stearate, magnesium stearate, and sodium hydroxymethylcellulose.

[0020] In a second aspect, the present invention provides a method for preparing an emulsion-type alkali-free accelerating setting agent, comprising the following steps:

[0021] (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A;

[0022] (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 60-80° C. and stirring evenly to obtain a mixed solution B;

[0023] (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

[0024] In summary, the present invention has the following beneficial effects:

[0025] 1. The present invention uses lysine, phosphoric acid and ethylenediaminetetraacetic acid as three complexing components to form an aluminum complex with aluminum sulfate to increase the liquid phase Al in the accelerator. 3+ The content of H + The pH of the solution can be lowered to inhibit Al 3+ The hydrolysis of the concrete achieves rapid setting and early strength, and the degree of hydration is improved.

[0026] 2. The modified polyacrylic acid polymer of the present invention has a three-dimensional porous network structure with uneven gaps formed by the accumulation of irregular colloidal particles. The three-dimensional skeleton is formed by a large number of large-particle colloids, which are aggregated by nano-scale small particles and have high thermal stability.

[0027] 3. The aluminum formate in the aluminum formate-modified aluminum sulfate added in the present invention provides additional Al for the aluminum sulfate-based alkali-free liquid accelerator. 3+ , which promotes the hydration process of cement, accelerates the hydration reaction, generates more needle-shaped calcium aluminate, and accelerates the hydration reaction of tricalcium aluminate, which is beneficial to the formation of CSH gel, shortens the cement setting time and improves the compressive strength.

[0028] 4. The emulsion-type alkali-free quick-setting agent prepared by the present invention helps to shorten the initial setting time and final setting time of concrete, and can also enhance the early strength of concrete.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not intended to limit the scope of protection of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0031] Preparation Example

[0032] Preparation Example 1

[0033] The preparation method of aluminum formate modified aluminum sulfate comprises the following steps:

[0034] S1: Formic acid and aluminum hydroxide were added into a beaker in a molar ratio of 1:1, heated to 60°C, reacted for 2 hours, and freeze-dried to obtain aluminum formate powder;

[0035] S2: Add water to a polytetrafluoroethylene beaker, heat to 60°C, add aluminum sulfate, stir until completely dissolved, add 1% by mass of the aluminum formate obtained in step S1, then add 5g of fluorosilicic acid, 10g of triethanolamine, and 12g of lithium carbonate in sequence, heat the mixed solution to 80°C, react for 1h, and then quickly cool to obtain aluminum formate-modified aluminum sulfate.

[0036] Preparation Example 2

[0037] The preparation method of aluminum formate modified aluminum sulfate comprises the following steps:

[0038] S1: Formic acid and aluminum hydroxide were added into a beaker in a molar ratio of 2:1, heated to 80°C, reacted for 2 hours, and freeze-dried to obtain aluminum formate powder;

[0039] S2: Add water to a polytetrafluoroethylene beaker, heat to 80°C, add aluminum sulfate, stir until completely dissolved, add 2% by mass of the aluminum formate obtained in step S1, then add 8g of fluorosilicic acid, 12g of triethanolamine, and 10g of lithium carbonate in sequence, heat the mixed solution to 80°C, react for 1h, and then quickly cool to obtain aluminum formate-modified aluminum sulfate.

[0040] Preparation Example 3

[0041] The preparation method of aluminum formate modified aluminum sulfate comprises the following steps:

[0042] S1: Formic acid and aluminum hydroxide were added into a beaker in a molar ratio of 3:1, heated to 80°C, reacted for 2 hours, and freeze-dried to obtain aluminum formate powder;

[0043] S2: Add water to a polytetrafluoroethylene beaker, heat to 80°C, add aluminum sulfate, stir until completely dissolved, add 4% of the aluminum formate obtained in step S1, then add 10g of fluorosilicic acid, 15g of triethanolamine, and 8g of lithium carbonate in sequence, heat the mixed solution to 100°C, react for 2h, and then quickly cool to obtain aluminum formate-modified aluminum sulfate.

[0044] Example

[0045] Example 1

[0046] The invention discloses an emulsion type alkali-free quick setting agent. The raw materials include, by weight, 50 parts of a coagulant component, 5 parts of fluorosilicate, 15 parts of aluminum formate-modified aluminum sulfate, 6 parts of a complexing component, 8 parts of an early strength component, 2 parts of a suspension component, 1 part of a pH adjusting component, 0.5 parts of an anti-caking component and 6 parts of a modified polyacrylic acid polymer.

[0047] The coagulant component is aluminum sulfate 18hydrate; the fluorosilicate is magnesium fluorosilicate;

[0048] Aluminum formate modified aluminum sulfate is prepared in Preparation Example 1;

[0049] The complexing component is a mixture of lysine, phosphoric acid and ethylenediaminetetraacetic acid in a mass ratio of 1:2:1;

[0050] The early strength component is diethanolamine; the modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin, and coordinating;

[0051] The suspension component is lignin sulfonate; the pH adjusting component is citric acid and anhydrous sodium hydroxide; and the anti-caking component is calcium stearate.

[0052] A method for preparing an emulsion-type alkali-free quick-setting agent comprises the following steps:

[0053] (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A;

[0054] (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 60° C. and stirring evenly to obtain a mixed solution B;

[0055] (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

[0056] Example 2

[0057] The invention discloses an emulsion type alkali-free quick setting agent. The raw materials include, by weight, 62 parts of a coagulant component, 8 parts of fluorosilicate, 18 parts of aluminum formate-modified aluminum sulfate, 8 parts of a complexing component, 10 parts of an early strength component, 3 parts of a suspension component, 2 parts of a pH adjusting component, 1 part of an anti-caking component, and 8 parts of a modified polyacrylic acid polymer.

[0058] The coagulant component is nano-hydrated calcium silicate; the fluorosilicate is zinc fluorosilicate;

[0059] Aluminum formate modified aluminum sulfate is prepared in Preparation Example 2;

[0060] The complexing component is a mixture of lysine, phosphoric acid and ethylenediaminetetraacetic acid in a mass ratio of 1:3:2;

[0061] The early strength component is hydrated aluminum sulfate; the modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin, and coordinating;

[0062] The suspension component is lignin sulfonate; the pH adjusting component is anhydrous sodium hydroxide; and the anti-caking component is microcrystalline cellulose.

[0063] A method for preparing an emulsion-type alkali-free quick-setting agent comprises the following steps:

[0064] (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A;

[0065] (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 80° C. and stirring evenly to obtain a mixed solution B;

[0066] (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

[0067] Example 3

[0068] The invention discloses an emulsion type alkali-free quick setting agent. The raw materials include, by weight, 55 parts of a coagulant component, 7 parts of fluorosilicate, 18 parts of aluminum formate-modified aluminum sulfate, 7 parts of a complexing component, 9 parts of an early strength component, 3 parts of a suspension component, 2 parts of a pH adjusting component, 1 part of an anti-caking component and 7 parts of a modified polyacrylic acid polymer.

[0069] The accelerating component is silica powder; the fluorosilicate is magnesium fluorosilicate;

[0070] Aluminum formate modified aluminum sulfate is prepared in Preparation Example 3;

[0071] The complexing component is a mixture of lysine, phosphoric acid and ethylenediaminetetraacetic acid in a mass ratio of 1:1:1;

[0072] The early strength component is solid alcohol amine; the modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin, and coordinating;

[0073] The suspension component is naphthalene sulfonate; the pH adjusting component is anhydrous calcium hydroxide; and the anti-caking component is calcium stearate.

[0074] A method for preparing an emulsion-type alkali-free quick-setting agent comprises the following steps:

[0075] (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A;

[0076] (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 75° C. and stirring evenly to obtain a mixed solution B;

[0077] (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

[0078] Example 4

[0079] An emulsion-type alkali-free quick-setting agent comprises, by weight, 68 parts of a coagulant component, 13 parts of fluorosilicate, 21 parts of aluminum formate-modified aluminum sulfate, 10 parts of a complexing component, 12 parts of an early strength component, 3 parts of a suspension component, 2 parts of a pH regulating component, 1 part of an anti-caking component, and 8 parts of a modified polyacrylic acid polymer.

[0080] The accelerating component is silicon carbon; the fluorosilicate is hexafluorosilicate;

[0081] Aluminum formate modified aluminum sulfate is prepared in Preparation Example 1;

[0082] The complexing component is a mixture of lysine, phosphoric acid and ethylenediaminetetraacetic acid in a mass ratio of 2:1:2;

[0083] The early strength component is diethanolamine; the modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin, and coordinating;

[0084] The suspension component is lignin sulfonate; the pH adjusting component is anhydrous sodium hydroxide; and the anti-caking component is sodium hydroxymethyl cellulose.

[0085] A method for preparing an emulsion-type alkali-free quick-setting agent comprises the following steps:

[0086] (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A;

[0087] (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 80° C. and stirring evenly to obtain a mixed solution B;

[0088] (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

[0089] Example 5

[0090] The invention discloses an emulsion type alkali-free quick setting agent. The raw materials include, by weight, 75 parts of a coagulant component, 15 parts of fluorosilicate, 25 parts of aluminum formate-modified aluminum sulfate, 12 parts of a complexing component, 15 parts of an early strength component, 4 parts of a suspension component, 3 parts of a pH adjusting component, 1 part of an anti-caking component, and 10 parts of a modified polyacrylic acid polymer.

[0091] The coagulant component is aluminum sulfate 18hydrate; the fluorosilicate is sodium fluorosilicate;

[0092] Aluminum formate modified aluminum sulfate is prepared in Preparation Example 2;

[0093] The complexing component is a mixture of lysine, phosphoric acid and ethylenediaminetetraacetic acid in a mass ratio of 2:1:3;

[0094] The early strength component is hydrated aluminum sulfate; the modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin, and coordinating;

[0095] The suspension component is lignin sulfonate; the pH adjusting component is anhydrous calcium carbonate; and the anti-caking component is magnesium stearate.

[0096] A method for preparing an emulsion-type alkali-free quick-setting agent comprises the following steps:

[0097] (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A;

[0098] (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 80° C. and stirring evenly to obtain a mixed solution B;

[0099] (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

[0100] Comparative Example 1

[0101] The powdered accelerating agent is selected from Shanxi Jiawei New Materials Co., Ltd., model 1801P.

[0102] Comparative Example 2

[0103] Powdered alkali-free accelerating setting agent selected from Yunnan Fluorine Industry Environmental Protection Technology Co., Ltd.

[0104] Comparative Example 3

[0105] The emulsion-type alkali-free quick-setting agent prepared according to the method of Example 2 is different in that aluminum formate-modified aluminum sulfate is not added.

[0106] Comparative Example 4

[0107] The emulsion-type alkali-free quick-setting agent prepared according to the method of Example 2 is different in that no modified polyacrylic acid polymer is added.

[0108] Performance Testing

[0109] The performance of the liquid alkali-free quick-setting agents prepared in Examples 1-5 and Comparative Examples 1-4 was tested, and the results are shown in Table 1 below.

[0110] The solid content test and pH value determination method of liquid alkali-free accelerating setting agent shall refer to GB / T 8077-2012 "Test method for homogeneity of concrete admixtures".

[0111] The stability determination method of liquid alkali-free accelerating setting agent shall refer to Appendix C of GB / T35159-2017 "Accelerating setting agent for shotcrete", and the stratification value results at room temperature after 28d, 60d, 90d and 120d of age shall be taken.

[0112] The test methods for setting time, 3h, 8h, 1d compressive strength, 28d compressive strength ratio, and 90d compressive strength retention rate of liquid alkali-free accelerating setting agent shall refer to Appendix D and F in GB / T35159-2017 Accelerating Setting Agent for Shotcrete, and the cement used shall be P·I42.5 standard cement.

[0113] Table 1 Performance test results of embodiments and comparative examples

[0114]

[0115]

[0116]

[0117] The relevant test results are shown in Table 1, which show that the aluminum formate in the aluminum sulfate modified aluminum sulfate emulsion-type alkali-free liquid setting agent of the present invention provides additional Al 3+, which promotes the hydration process of cement, accelerates the hydration reaction, generates more needle-shaped calcium aluminate, and accelerates the hydration reaction of tricalcium aluminate, which is beneficial to the formation of CSH gel, shortens the cement setting time and improves the compressive strength. All indicators meet the requirements of GB / T35159-2017 "Accelerator for Shotcrete". The emulsion-type alkali-free accelerator has been verified again. It can be compounded into liquid products with different solid contents according to the adaptability of different cements at the site of use, and can also be compounded to introduce multiple components such as aluminum sulfate and mother liquor, which not only improves the product performance, but also reduces the cost of compounding to a certain extent, realizes the diversification of products, not only reduces the packaging and transportation costs, but also adds more adjustment plans for on-site compounding.

[0118] The emulsion-type alkali-free quick-setting agent prepared by the present invention has excellent quick-setting effect and good product stability, and can be compounded with an early-strength component to obtain an early-strength liquid alkali-free quick-setting agent, which can take into account both product stability and early-strength performance, has good early strength, and is not easy to precipitate.

[0119] The above is only an exemplary embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An emulsion-type alkali-free quick-setting agent, characterized in that: The raw materials include, by weight: 50-75 parts of accelerating coagulant component, 5-15 parts of fluorosilicate, 15-25 parts of aluminum formate modified aluminum sulfate, 6-12 parts of complexing component, 8-15 parts of early strength component, 2-4 parts of suspension component, 1-3 parts of pH adjusting component, 0.5-1 part of anti-caking component and 6-10 parts of modified polyacrylic acid polymer.

2. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The accelerating coagulant component is one of aluminum sulfate 18hydrate, nano calcium silicate hydrate, silica powder, silicon carbon and glass powder.

3. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The fluorosilicate is one of magnesium fluorosilicate, zinc fluorosilicate, sodium fluorosilicate, potassium fluorosilicate and hexafluorosilicate.

4. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The preparation method of aluminum formate modified aluminum sulfate comprises the following steps: S1: Add formic acid and aluminum hydroxide in a molar ratio of (1-4):1 into a beaker, heat to 60-80°C, react for 2-3 hours, and freeze-dry to obtain aluminum formate powder; S2: Add water to a polytetrafluoroethylene beaker, heat to 60-80°C, add aluminum sulfate, stir until completely dissolved, add 1%-4% by mass of the aluminum formate obtained in step S1, then add fluorosilicic acid, triethanolamine, and lithium carbonate in sequence, heat the mixed solution to 80-100°C, react for 1-2h, and then quickly cool to obtain aluminum formate-modified aluminum sulfate.

5. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The complexing components are lysine, phosphoric acid and ethylenediaminetetraacetic acid, and the mass ratio of lysine, phosphoric acid and ethylenediaminetetraacetic acid is 1-2:1-4:1-3.

6. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The early strength component is one or more of diethanolamine, hydrated aluminum sulfate and solid alcoholamine.

7. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The modified polyacrylic acid polymer is prepared by using polyacrylic acid as a long chain skeleton, adding nickel chloride and epoxy resin for coordination.

8. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The suspension component is one of lignin sulfonate, naphthalene sulfonate, formaldehyde condensate, magnesium aluminum silicate, quartz, feldspar and carbonate; the pH adjusting component is one or more of citric acid, anhydrous sodium hydroxide, anhydrous calcium hydroxide and anhydrous calcium carbonate.

9. The emulsion-type alkali-free quick-setting agent according to claim 1, characterized in that: The anti-caking component is one or more of microcrystalline cellulose, calcium stearate, magnesium stearate and sodium hydroxymethylcellulose.

10. The method for preparing the emulsion type alkali-free quick-setting agent according to any one of claims 1 to 9, characterized in that: The steps include: (1) dissolving a coagulant component, fluorosilicate, and aluminum formate-modified aluminum sulfate in water, and subjecting the mixture to ultrasonic treatment to obtain a mixed solution A; (2) adding the complexing component, the early strength component, the suspension component and the modified polyacrylic acid polymer to the mixed solution A at 60-80° C. and stirring evenly to obtain a mixed solution B; (3) Add the pH adjusting component and the anti-caking component to the mixed solution B and continue stirring to obtain an emulsion type alkali-free quick-setting agent.

Images