A fluorine-containing quick-setting agent and its preparation method

Abstract

The present invention provides a fluorine-containing accelerator and a preparation method thereof, relating to the technical field of accelerator preparation. The fluorine-containing accelerator comprises the following weight percentages: liquid sodium aluminate: 8-15%; aluminum sulfate: 40-50%; fluoride salt: 6-9%; alcoholamine: 4-8%; and water: 25-32%; the sum of these components being 100%. The fluorine-containing accelerator does not produce particle precipitation during preparation, making the preparation process easy to operate.

Description

Technical Field

[0001] The present invention relates to the technical field of quick-setting agent preparation, in particular to a fluorine-containing quick-setting agent and a preparation method thereof. Background Art

[0002] Fluorinated accelerators, as concrete admixtures, effectively shorten the setting and hardening time of cement and are widely used in shotcrete and rapid leak plugging. Currently, there are many types of fluorinated accelerators on the market, which can be roughly divided into two categories: one is composed primarily of aluminum sulfate and carbonates, combined with other inorganic salts; the other is composed primarily of sodium silicate, combined with other inorganic salts.

[0003] Fluorinated cement accelerators based primarily on aluminum sulfate and carbonates are widely used due to their rapid setting and hardening. However, in actual production, it has been found that existing fluorinated cement accelerators based primarily on aluminates are prone to particle precipitation during preparation, which introduces unnecessary complications to the accelerator preparation process.

[0004] Therefore, providing a fluorine-containing quick-setting agent that is not prone to particle precipitation during the preparation process has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] (1) Technical problems solved

[0006] In view of the shortcomings of the existing technology, the present invention provides a fluorine-containing accelerator and a preparation method thereof, which solves the technical problem that the existing fluorine-containing accelerator mainly based on aluminate is very likely to produce particle precipitation during the preparation process.

[0007] (2) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A fluorine-containing quick-setting agent, wherein the weight percentage of the quick-setting agent formula is:

[0010] Liquid sodium aluminate: 8-15%;

[0011] Aluminum sulfate: 40-50%;

[0012] Fluoride salt: 6-9%;

[0013] Alcoholamine: 4-8%;

[0014] Water: 25-32%;

[0015] The sum of the components is 100%.

[0016] Preferably, the fluoride salt is selected from at least one of sodium fluorosilicate and magnesium fluorosilicate.

[0017] Preferably, the fluoride salt includes sodium fluorosilicate and magnesium fluorosilicate, and the mass ratio of the sodium fluorosilicate to the magnesium fluorosilicate is (5-7):(2-3).

[0018] Preferably, the fluoride salt includes sodium fluorosilicate and magnesium fluorosilicate, and the mass ratio of the sodium fluorosilicate to the magnesium fluorosilicate is 6:2.5.

[0019] Preferably, the liquid sodium aluminate comprises aluminum hydroxide and sodium hydroxide.

[0020] Preferably, the stability of the quick-setting agent is ≥90 days.

[0021] On the other hand, a method for preparing a fluorine-containing accelerating setting agent comprises the following steps:

[0022] 1) adding water, aluminum hydroxide, and sodium hydroxide in a mass ratio of sodium hydroxide to aluminum hydroxide of 1:1.2-1.5, heating to 90-110° C., and keeping warm for 1-2 hours to obtain a liquid sodium aluminate solution;

[0023] 2) adding water to the liquid sodium aluminate solution, stirring evenly, then adding a fluoride salt to the liquid sodium aluminate solution, stirring, and reacting at 50-80° C. for 0.5-1 h;

[0024] 3) After the fluoride salt reacts completely, add aluminum sulfate and continue the reaction for 1-2 hours;

[0025] 4) adding organic alcohol amine and stirring for 0.5 to 1 hour to obtain the fluorine-containing accelerating setting agent.

[0026] Preferably, in step 3), aluminum sulfate is added after the fluoride salt has reacted completely.

[0027] Preferably, in step 1), the mass concentration of liquid sodium aluminate is 55-65%.

[0028] (3) Beneficial effects

[0029] The present invention provides a fluorine-containing accelerating setting agent and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0030] The fluorine-containing quick-setting agent provided by the present invention comprises liquid sodium aluminate and a fluoride salt, wherein the fluoride salt comprises sodium fluorosilicate and / or magnesium fluorosilicate. Sodium fluorosilicate and magnesium fluorosilicate are insoluble in water, but their aqueous solutions are acidic because their hydrolysis products contain hydrofluoric acid. Liquid sodium aluminate is alkaline, with a pH of approximately 11, and the liquid sodium aluminate can completely hydrolyze the fluoride salt to form silica gel. After the fluoride salt hydrolysis reaction, aluminum sulfate is added. The silica gel effectively encapsulates the fluoride ions, slowing the contact speed between the fluoride ions and the aluminum ions in the aluminum sulfate during the preparation process, thereby preventing the rapid formation of aluminum fluoride particles and agglomeration into granular precipitates. Therefore, the fluorine-containing quick-setting agent of the present invention does not produce granular precipitates during the preparation process, and the preparation process is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 This is a photo of the fluorine-containing quick-setting agent prepared in Example 1;

[0033] Figure 2 This is a photo of the fluorine-containing quick-setting agent prepared in Comparative Example 1; DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0035] The embodiments of the present application provide a fluorine-containing accelerating setting agent and a preparation method thereof, thereby solving the technical problem that the existing fluorine-containing accelerating setting agent mainly based on aluminate is very prone to particle precipitation during the preparation process.

[0036] The technical solution in the embodiments of the present application is to solve the above technical problems, and the overall idea is as follows:

[0037] Fluoride salts include sodium fluorosilicate and / or magnesium fluorosilicate. Sodium and magnesium fluorosilicate are poorly soluble in water, but their aqueous solutions are acidic due to the presence of hydrofluoric acid in their hydrolysis products. Sodium metaaluminate, on the other hand, hydrolyzes to an alkaline pH of around 11, allowing the fluoride salts to completely hydrolyze into silica gel. The silica gel effectively encapsulates the fluoride ions, slowing their subsequent contact with the aluminum ions in aluminum sulfate, thereby preventing the rapid formation of aluminum fluoride particles and their subsequent aggregation into precipitated particles.

[0038] The fluoride salt is sodium fluorosilicate and magnesium fluorosilicate. When the mass ratio of sodium fluorosilicate to magnesium fluorosilicate is (5-7):(2-3), sodium fluorosilicate and magnesium fluorosilicate act synergistically to ensure that the stability of the fluorine-containing accelerator is greater than or equal to 90 days.

[0039] The preparation method of the fluorine-containing accelerating setting agent comprises the following steps:

[0040] 1) adding water, aluminum hydroxide, and sodium hydroxide in a mass ratio of sodium hydroxide to aluminum hydroxide of 1:1.2-1.5, heating to 90-110° C., and keeping warm for 1-2 hours to obtain a liquid sodium aluminate solution;

[0041] 2) adding water to the liquid sodium aluminate solution, wherein the mass concentration of the liquid sodium aluminate is 55-65%, and stirring uniformly to obtain a liquid sodium aluminate solution having a pH value of 11; then adding a fluoride salt to the liquid sodium aluminate solution, stirring, and reacting at 50-80° C. for 0.5-1 hour, wherein the fluoride salt is completely hydrolyzed by the liquid sodium aluminate solution to form silica gel, and the silica gel preferably encapsulates the fluoride ions generated by the hydrolysis;

[0042] 3) After the fluoride salt reaction is complete and the system becomes uniformly milky white, aluminum sulfate is added and the reaction is continued for 1-2 hours; the fluoride ions produced by the fluoride salt reaction are well encapsulated by the generated silica gel, thereby slowing down the reaction rate of the fluoride ions and aluminum ions, thereby preventing the rapid generation of aluminum fluoride particles and preventing a large amount of aluminum fluoride from agglomerating into particle precipitation.

[0043] 4) Adding organic alcohol amine can promote the dissolution of aluminum sulfate, significantly improve the setting time of the slurry and the compressive strength of the mortar, and the fluorine-containing accelerating setting agent is prepared by stirring for 0.5 to 1 hour.

[0044] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0045] Example 1:

[0046] This embodiment provides an accelerating setting agent, the weight percentage of the formula is:

[0047] Liquid sodium aluminate: 8%;

[0048] Aluminum sulfate: 50%;

[0049] Fluoride salt: 9%;

[0050] Organic alcohol amine: 7%;

[0051] Water: 26%;

[0052] The preparation method of the fluorine-containing catalyst comprises the following steps:

[0053] 1) adding water, aluminum hydroxide, and sodium hydroxide in a mass ratio of 1:1.2 to sodium hydroxide and aluminum hydroxide, heating to 90° C. and keeping warm for 1 hour to obtain a liquid sodium aluminate solution with a mass concentration of 55%;

[0054] 2) adding water to the liquid sodium aluminate solution, stirring evenly, then adding fluoride salt to the liquid sodium aluminate solution, stirring, and reacting at 50° C. for 0.5 h;

[0055] Fluoride salts include sodium fluorosilicate and magnesium fluorosilicate, with a mass ratio of 6:2.5;

[0056] 3) After the fluoride salt reacts completely, add aluminum sulfate and continue the reaction for 1 hour;

[0057] 4) adding organic alcohol amine and stirring for 0.5 h to obtain the fluorine-containing accelerating setting agent.

[0058] The prepared fluorine-containing quick-setting agent is shown in the photo Figure 1 As shown, the prepared fluorine-containing quick-setting agent has no particulate matter.

[0059] Example 2

[0060] This embodiment provides a fluorine-containing accelerating setting agent, and the weight percentage of the accelerating setting agent formula is:

[0061] Liquid sodium aluminate: 15%;

[0062] Aluminum sulfate: 45%;

[0063] Fluoride salt: 9%;

[0064] Organic alcohol amine: 8%;

[0065] Water: 23%;

[0066] The preparation method of the fluorine-containing catalyst comprises the following steps:

[0067] 1) adding water, aluminum hydroxide, and sodium hydroxide in a mass ratio of 1:1.3 between sodium hydroxide and aluminum hydroxide, heating to 100° C., and maintaining the temperature for 1.5 hours to obtain a liquid sodium aluminate solution having a mass concentration of 60%;

[0068] 2) adding water to the liquid sodium aluminate solution, stirring evenly, then adding fluoride salt to the liquid sodium aluminate solution, stirring, and reacting at 65° C. for 0.8 h;

[0069] Fluoride salts include sodium fluorosilicate and magnesium fluorosilicate, with a mass ratio of 6:2.5;

[0070] 3) After the fluoride salt reacts completely, aluminum sulfate is added and the reaction is continued for 1.5 hours;

[0071] 4) adding organic alcohol amine and stirring for 0.8 h to obtain the fluorine-containing accelerating setting agent.

[0072] The prepared fluorine-containing quick-setting agent has no particles.

[0073] Example 3

[0074] This embodiment provides a fluorine-containing accelerating setting agent, and the weight percentage of the accelerating setting agent formula is:

[0075] Liquid sodium aluminate: 8%;

[0076] Aluminum sulfate: 50%;

[0077] Fluoride salt: 9%;

[0078] Alkylamine: 4%;

[0079] Water: 29%;

[0080] The preparation method of the fluorine-containing catalyst comprises the following steps:

[0081] 1) adding water, aluminum hydroxide, and sodium hydroxide in a mass ratio of 1:1.5 of sodium hydroxide to aluminum hydroxide, heating to 110° C. and keeping warm for 2 hours to obtain a liquid sodium aluminate solution with a mass concentration of 65%;

[0082] 2) adding water to the liquid sodium aluminate solution, stirring evenly, then adding fluoride salt to the liquid sodium aluminate solution, stirring, and reacting at 80° C. for 1 hour;

[0083] Fluoride salts include sodium fluorosilicate and magnesium fluorosilicate, with a mass ratio of 6:2.5;

[0084] 3) After the fluoride salt reacts completely, aluminum sulfate is added and the reaction is continued for 2 hours;

[0085] 4) adding organic alcohol amine and stirring for 1 hour to obtain the fluorine-containing accelerating setting agent.

[0086] The prepared fluorine-containing quick-setting agent has no particles.

[0087] Comparative Example 1:

[0088] The difference between this comparative example and Example 1 is that the order of adding materials is different, and the rest is the same as Example 1. The order of adding materials in this comparative example is:

[0089] Add liquid sodium aluminate and water under stirring conditions, then add aluminum sulfate, continue stirring until all are dissolved, then add fluoride salt, continue stirring under heat preservation conditions, then add organic alcohol amine, continue stirring under heat preservation conditions to obtain a fluorine-containing accelerator.

[0090] The prepared fluorine-containing quick-setting agent is shown in the photo Figure 2 As shown, the prepared fluorine-containing quick-setting agent has obvious particles.

[0091] Comparative Example 2:

[0092] The difference between this comparative example and Example 1 is that sodium fluorosilicate is selected as the fluoride salt, and the rest is the same as Example 1. The prepared fluorine-containing accelerator is free of particulate matter.

[0093] Comparative Example 3:

[0094] The difference between this comparative example and Example 1 is that magnesium fluorosilicate is selected as the fluoride salt, and the rest is the same as Example 1. The prepared fluorine-containing accelerator is free of particulate matter.

[0095] The stability, particulate matter, setting time of cement paste and compressive strength of the fluorine-containing accelerators prepared in Examples 1-3 and Comparative Examples 1-3 were tested, and the results are shown in Table 1. The test method is as follows:

[0096] Test methods for cement paste setting time and cement mortar compressive strength:

[0097] According to GB / T 35159-2017, "Accelerators for Shotcrete," accelerators were added to cement paste or cement mortar at 5% or 7% by weight of cement to test setting time and compressive strength. The cement paste setting time ratio was: base cement: water = 400:140. The cement mortar compressive strength ratio was: base cement: standard sand: water = 900:1350:450.

[0098] Stability test method: Place the prepared fluorine-containing quick-setting agent in a room at room temperature and pressure, observe the state of its solution, and record the time when the coagulant appears.

[0099] Table 1 Test results of stability, corresponding setting time and compressive strength of fluorinated accelerator

[0100]

[0101] As shown in Table 1, the fluorine-containing accelerators prepared in Examples 1-3 produced no particles. The fluorine-containing accelerator prepared in Comparative Example 1 produced obvious particles. The fluorine-containing accelerators prepared in Comparative Examples 2 and 3 also produced no particles, but exhibited significant crystallization and solidification after 14 and 15 days of storage. This indicates that the fluorine-containing accelerators prepared using only magnesium fluorosilicate or sodium fluorosilicate, while not producing particles during the preparation process, exhibited poor stability. The fluoride salts selected from magnesium fluorosilicate and sodium fluorosilicate, when used in conjunction, not only did not produce particulate matter during the preparation process, but also resulted in fluorine-containing accelerators with a stability of over 90 days.

[0102] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0103] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A fluorine-containing quick-setting agent, characterized in that: The weight percentage of the quick-setting agent formula: Liquid sodium aluminate: 8-15%; Aluminum sulfate: 40-50%; Fluoride salt: 6-9%; Alcoholamine: 4-8%; Water: 25-32%; The sum of the components is 100%; The fluoride salt is selected from at least one of sodium fluorosilicate and magnesium fluorosilicate; The fluoride salt is added to liquid sodium aluminate, and aluminum sulfate is added after the fluoride salt reacts completely.

2. The fluorine-containing quick-setting agent according to claim 1, characterized in that The fluoride salt includes sodium fluorosilicate and magnesium fluorosilicate, and the mass ratio of the sodium fluorosilicate to the magnesium fluorosilicate is (5-7):(2-3).

3. The fluorine-containing quick-setting agent according to claim 1, characterized in that The fluoride salt includes sodium fluorosilicate and magnesium fluorosilicate, and the mass ratio of the sodium fluorosilicate to the magnesium fluorosilicate is 6:2.

5.

4. The fluorine-containing quick-setting agent according to claim 1, characterized in that The liquid sodium aluminate comprises aluminum hydroxide and sodium hydroxide.

5. The fluorine-containing quick-setting agent according to claim 1, characterized in that The stability of the quick-setting agent is ≥90 days.

6. A method for preparing a fluorine-containing accelerating setting agent according to any one of claims 1 to 5, characterized in that: The steps include: 1) adding water, aluminum hydroxide, and sodium hydroxide in a mass ratio of sodium hydroxide to aluminum hydroxide of 1:1.2-1.5, heating to 90-110° C., and keeping warm for 1-2 hours to obtain a liquid sodium aluminate solution; 2) adding water to the liquid sodium aluminate solution and stirring evenly, then adding a fluoride salt to the liquid sodium aluminate solution and stirring, reacting at 50-80° C. for 0.5-1 h; 3) After the fluoride salt reacts completely, add aluminum sulfate and continue the reaction for 1-2 hours; 4) adding organic alcohol amine and stirring for 0.5 to 1 hour to obtain the fluorine-containing accelerating setting agent.

7. The preparation method according to claim 6, wherein In step 3), after the fluoride salt is completely dissolved, aluminum sulfate is added.

8. The preparation method according to claim 6, wherein In the step 1), the mass concentration of liquid sodium aluminate is 55-65%.

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