Low-temperature-resistant fluoride-free alkali-free liquid accelerator and normal-temperature preparation method thereof

Abstract

The invention relates to the technical field of underground mine engineering filling paste additives, in particular to a low-temperature-resistant fluoride-free alkali-free liquid accelerator and a normal-temperature preparation method of the low-temperature-resistant fluoride-free alkali-free liquid accelerator. The low-temperature-resistant fluoride-free alkali-free liquid accelerator comprises aluminum sulfate, a suspension component, an anti-freezing component, an organic complexing component, a solubilizing component, a conditioning agent and the balance of water. The setting of the alcohol amine compound improves the early strength of cement after the accelerator is added, complexes aluminum ions and improves the storage stability of the accelerator, the setting of the pH adjusting component controls the pH value of the accelerator to be 2-3 and improves the solubility of aluminum sulfate, the setting of the alkylphenol polyoxyethylene ether improves the solubility of aluminum sulfate at normal temperature, and the setting of the accelerator improves the stability of the accelerator. The low-temperature-resistant fluoride-free alkali-free liquid accelerator provided by the technical scheme has good adaptability to various types of cement, and overcomes the defects of strong corrosivity, poor workability, slow setting time, large later strength loss and the like of the traditional alkaline accelerator.

Description

Technical Field

[0001] The invention relates to the technical field of filling paste additives for underground mine engineering, and in particular to a low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent and a preparation method thereof at room temperature. Background Art

[0002] In recent years, coal mining has produced a large number of goafs, which has brought many problems to economic and social development. Most coal mining is carried out through underground mines, and most of them use longwall mining methods. With the advancement of coal mining technology, the speed of coal mining has continued to accelerate, and the area of ​​goafs has also expanded, seriously affecting industrial production and people's lives. Using cement, fly ash and coal gangue to make paste materials for goaf filling can not only fill the goaf, but also absorb a large amount of coal gangue, achieving two goals at one stroke, and pointing the way for the green mining of coal resources. Accelerator is a chemical admixture that can make cement-based materials set and harden quickly. Since the current filling system construction requires the paste to be self-sustaining quickly to improve construction efficiency, accelerator has become an indispensable component, and its demand is also increasing.

[0003] At present, the accelerators used in the market generally contain substances such as alkali metal hydroxides, carbonates, aluminates and silicates. Although they can meet the requirements of use, due to the strong alkalinity of these substances that make up the accelerator, there are many problems during the construction process and in the later stage of construction, such as large strength loss in the later stage, strong corrosiveness, poor durability and other problems, especially the corrosion problem caused by chloride ions and strong alkali metal ions, which is likely to cause alkali-aggregate reaction in cement-based materials in the later stage; at the same time, due to the low solubility of aluminum sulfate at room temperature, the production and synthesis process usually requires the introduction of a heat source, which is inconvenient to operate and has high production costs. Summary of the invention

[0004] The object of the present invention is to provide a low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent and a method for preparing the same at room temperature, so as to solve the problems that the quick-setting agents currently used in the market generally contain substances such as alkali metal hydroxides, carbonates, aluminates and silicates. Although the quick-setting agents can meet the use requirements, due to the strong alkalinity of these substances constituting the quick-setting agents, there are problems such as large strength loss in the later stage, strong corrosion and poor durability during the construction process and in the later stage of construction.

[0005] To achieve the above object, the present invention provides a low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent, which comprises the following components, measured by mass percentage: 55% to 60% aluminum sulfate, 0.5% to 1.0% suspension component, 1% to 3% antifreeze component, 2% to 3% organic complex component, 1.4% to 2.5% solubilizing component and 0.2% to 0.4% pH regulator, and the balance is water.

[0006] The organic complexing component is diethanolamine, the content of which is ≥99%, the aluminum sulfate is industrial-grade aluminum sulfate 18hydrate, the aluminum sulfate has an aluminum oxide content of ≥15.8%, and the aluminum sulfate is in the form of flakes.

[0007] The antifreeze agent is prepared from urea and ethylene glycol in a mass ratio of (1-1): (1-0.5): (0.5-1).

[0008] Wherein, the suspending agent is forsterite powder, the solubilizing component is alkylphenol polyoxyethylene ether, and the pH regulator is glycolic acid or oxalic acid.

[0009] The present invention also provides a method for preparing a low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent at room temperature, which is applied to the low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent as described above, and comprises the following steps:

[0010] S1: Add water to a reaction container, add the solubilizing component to the reaction container, and continue stirring until it is completely dissolved;

[0011] S2: slowly add the suspending agent into the container, continue stirring for 30 minutes until it is completely dissolved to form a suspension solution, then add 1 / 2 of the total amount of aluminum sulfate, and continue stirring for 30 minutes;

[0012] S3: slowly dripping the organic complex component into a container, then adding 1 / 2 of the total amount of aluminum sulfate, and stirring continuously for 30 minutes;

[0013] S4: slowly add the antifreeze component into the container, maintain the temperature and continue stirring for 30 minutes;

[0014] S5: adding the pH adjusting component and stirring until the solution is clear, thereby obtaining the low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0015] The invention discloses a low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent and a preparation method thereof at room temperature. The liquid quick-setting agent comprises aluminum sulfate, a suspension component, an antifreeze component, an organic complexing component, a solubilizing component and a regulator, with the balance being water. The aluminum sulfate is provided to shorten the cement setting time, the alcohol amine compound is provided to improve the early strength of the cement after adding the quick-setting agent, the aluminum ions are complexed, and the storage stability of the quick-setting agent is improved, the pH value of the quick-setting agent is controlled to be between 2 and 3 by the pH regulating component, and the solubility of the aluminum sulfate is improved, and the solubility of the aluminum sulfate at room temperature is improved by the micelle formation and hydrophobic effect of the alkylphenol polyoxyethylene ether. The low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent provided by the technical solution has good adaptability to various cements, overcomes the shortcomings of traditional alkaline quick-setting agents such as strong corrosiveness, poor workability, slow setting time, large later strength loss, etc., and has a simple production process, no need for heating, low raw material cost, and is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0017] Figure 1 The invention discloses a flow chart of steps for preparing a low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent at room temperature. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0019] See also Figure 1 The present invention provides a low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent, which comprises the following components, measured by mass percentage: 55% to 60% aluminum sulfate, 0.5% to 1.0% suspension component, 1% to 3% antifreeze component, 2% to 3% organic complex component, 1.4% to 2.5% solubilizing component and 0.2% to 0.4% pH regulator, and the balance is water.

[0020] The organic complexing component is diethanolamine, the content of which is ≥99%, the aluminum sulfate is industrial-grade aluminum sulfate 18hydrate, the aluminum sulfate has an aluminum oxide content of ≥15.8%, and the aluminum sulfate is in the form of flakes.

[0021] The antifreeze agent is prepared from urea and ethylene glycol in a mass ratio of (1-1): (1-0.5): (0.5-1).

[0022] Wherein, the suspending agent is forsterite powder, the solubilizing component is alkylphenol polyoxyethylene ether, and the pH regulator is glycolic acid or oxalic acid.

[0023] In this embodiment, the setting of aluminum sulfate shortens the cement setting time, the setting of the alcoholamine compound improves the early strength of cement after adding the accelerator, chelates aluminum ions, and improves the storage stability of the accelerator, the setting of the pH adjusting component controls the pH value of the accelerator between 2-3, improves the solubility of the aluminum sulfate, and improves the solubility of the aluminum sulfate at room temperature through the micelle formation and hydrophobic effect of the alkylphenol polyoxyethylene ether. The low-temperature resistant fluorine-free and alkali-free liquid accelerator provided by this technical solution has good adaptability to various cements, overcomes the shortcomings of traditional alkaline accelerators such as strong corrosiveness and poor workability, slow setting time, and large strength loss in the later stage, and the production process is simple, no heating is required, the raw material cost is low, and it is suitable for large-scale production. It can be widely used in the sprayed concrete construction and plugging of mine filling projects, shaft and tunnel projects, traffic tunnel projects, urban construction, water conservancy projects, etc., rapid construction of ground cement, emergency rescue, emergency repair and reinforcement projects.

[0024] The present invention also provides a method for preparing a low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent at room temperature, which is applied to the low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent as described above, and comprises the following steps:

[0025] S1: Add water to a reaction container, add the solubilizing component to the reaction container, and continue stirring until it is completely dissolved;

[0026] S2: slowly add the suspending agent into the container, continue stirring for 30 minutes until it is completely dissolved to form a suspension solution, then add 1 / 2 of the total amount of aluminum sulfate, and continue stirring for 30 minutes;

[0027] S3: slowly dripping the organic complex component into a container, then adding 1 / 2 of the total amount of aluminum sulfate, and stirring continuously for 30 minutes;

[0028] S4: slowly add the antifreeze component into the container, maintain the temperature and continue stirring for 30 minutes;

[0029] S5: adding the pH adjusting component and stirring until the solution is clear, thereby obtaining the low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0030] Embodiment 1:

[0031] A low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent is synthesized at room temperature, including industrial aluminum sulfate, forsterite powder, urea, ethylene glycol, diethanolamine, alkylphenol polyoxyethylene ether, and glycolic acid. The specific preparation steps are as follows:

[0032] S101: Add 399 g of deionized water and 14 g of alkylphenol polyoxyethylene ether to a three-necked flask in sequence, and stir until completely dissolved;

[0033] S102: Add 5 g of forsterite powder into a three-necked flask, continue stirring for 30 min, then add 300 g of aluminum sulfate, and continue stirring for 30 min;

[0034] S103: 20 g of diethanolamine was dropped into a three-necked flask, and then 250 g of aluminum sulfate was added, and stirring was continued for 30 min;

[0035] S104: Add 5 g of urea and 5 g of ethylene glycol into a three-necked flask and continue stirring for 30 min;

[0036] S105: Add 2 g of glycolic acid and stir until the solution is clear to obtain the low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0037] Embodiment 2:

[0038] A low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent is synthesized at room temperature, including industrial aluminum sulfate, forsterite powder, urea, ethylene glycol, diethanolamine, alkylphenol polyoxyethylene ether, and glycolic acid. The specific preparation steps are as follows:

[0039] S201: Add 371 g of deionized water and 20 g of alkylphenol polyoxyethylene ether to a three-necked flask in sequence, and stir until completely dissolved;

[0040] S202: 10 g of forsterite powder was added to a three-necked flask, and the mixture was stirred for 30 min. Then, 300 g of aluminum sulfate was added, and the mixture was stirred for 30 min.

[0041] S203: 25 g of diethanolamine was dropped into a three-necked flask, and then 250 g of aluminum sulfate was added, and stirring was continued for 30 min;

[0042] S204: Add 10 g of urea and 10 g of ethylene glycol into a three-necked flask and continue stirring for 30 min;

[0043] S205: Add 4 g of glycolic acid and stir until the solution is clear to obtain the low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0044] Embodiment 3:

[0045] A low-temperature resistant fluorine-free and alkali-free liquid accelerating agent is synthesized at room temperature, including industrial aluminum sulfate, forsterite powder, urea, ethylene glycol, diethanolamine, alkylphenol polyoxyethylene ether, and oxalic acid. The specific preparation steps are as follows:

[0046] S301: Add 317 g of deionized water and 25 g of alkylphenol polyoxyethylene ether to a three-necked flask in sequence, and stir until completely dissolved;

[0047] S302: 10 g of forsterite powder was added to a three-necked flask, and the mixture was stirred for 30 min. Then, 300 g of aluminum sulfate was added, and the mixture was stirred for 30 min.

[0048] S303: 30 g of diethanolamine was dropped into a three-necked flask, and then 300 g of aluminum sulfate was added, and stirring was continued for 30 min;

[0049] S304: Add 10 g of urea and 5 g of ethylene glycol into a three-necked flask and continue stirring for 30 min;

[0050] S305: Add 3 g of oxalic acid and stir until the solution is clear to obtain the low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0051] Embodiment 4:

[0052] A low-temperature resistant fluorine-free and alkali-free liquid accelerating agent is synthesized at room temperature, including industrial aluminum sulfate, forsterite powder, urea, ethylene glycol, diethanolamine, alkylphenol polyoxyethylene ether, and oxalic acid. The specific preparation steps are as follows:

[0053] S401: Add 302 g of deionized water and 25 g of alkylphenol polyoxyethylene ether to a three-necked flask in sequence, and stir until completely dissolved;

[0054] S402: 10 g of forsterite powder was added to a three-necked flask, and the mixture was stirred for 30 min. Then, 300 g of aluminum sulfate was added, and the mixture was stirred for 30 min.

[0055] S403: 30 g of diethanolamine was dropped into a three-necked flask, and then 300 g of aluminum sulfate was added, and stirring was continued for 30 min;

[0056] S404: Add 10 g urea and 20 g ethylene glycol into a three-necked flask and continue stirring for 30 min;

[0057] S405: Add 3 g of oxalic acid and stir until the solution is clear to obtain the low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0058] Embodiment 5:

[0059] A low-temperature resistant fluorine-free and alkali-free liquid quick-setting agent is synthesized at room temperature, including industrial aluminum sulfate, forsterite powder, urea, ethylene glycol, diethanolamine, alkylphenol polyoxyethylene ether, and glycolic acid. The specific preparation steps are as follows:

[0060] S501: Add 330 g of deionized water and 20 g of alkylphenol polyoxyethylene ether to a three-necked flask in sequence, and stir until completely dissolved;

[0061] S502: 8 g of forsterite powder was added to a three-necked flask, and the mixture was stirred for 30 min. Then, 290 g of aluminum sulfate was added, and the mixture was stirred for 30 min.

[0062] S503: 30 g of diethanolamine was dropped into a three-necked flask, and then 290 g of aluminum sulfate was added, and stirring was continued for 30 min;

[0063] S504: Add 20 g of urea and 10 g of ethylene glycol into a three-necked flask and continue stirring for 30 min;

[0064] S505: Add 2 g of glycolic acid and stir until the solution is clear to obtain the low-temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

[0065] Furthermore, the low temperature stability of the low temperature resistant fluorine-free and alkali-free liquid quick-setting agent of the technical solution was tested. The quick-setting agents of Examples 1-5 and Comparative Examples 1-3 were packaged in 100 ml measuring cylinders with stoppers according to the standard, stored in a -5°C refrigerator, and the V precipitation was continuously measured. The experimental results are shown in Table 1. At the same time, the coagulation effects of different quick-setting agents at the time of 7d and 28d of low temperature storage were tested, as shown in Table 2:

[0066] Table 1: Test results of low temperature stability of accelerators in Examples and Comparative Examples

[0067]

[0068] Table 2: Low temperature storage setting time of the fast setting agent in the examples and comparative examples

[0069]

[0070]

[0071] It can be seen from the table that this technical solution has excellent stability compared with the products on the market, with storage stability of up to 90 days, and storage in a low-temperature environment will not have a significant impact on the performance, while the control ratio is basically in an ineffective state after 28 days of low-temperature storage. Low-temperature stability is related to the antifreeze component and the suspension component. The suspension component provides suspension for the solution, controls the rheology of the accelerator liquid, and inhibits the stratification and precipitation of the accelerator by adjusting the interaction force between the particles, thereby improving the overall stability. The antifreeze component can lower the freezing point of the solution and further protect the stability in a low-temperature environment.

[0072] Although this technical solution is applied to filling paste, its reference standard still needs to be based on GB / T35159-2017 "Accelerator for Shotcrete". The relevant project test method detects the various performance indicators of Examples 1-5 and other manufacturers' liquid alkali-free accelerator comparative examples 1-3. The specific test results are shown in Table 3:

[0073] Table 3: Comparison of performance indicators of alkali-free quick-setting agents of the embodiments and comparative examples

[0074]

[0075]

[0076] Note: S in the table represents the solid content controlled by the manufacturer

[0077] It can be seen from the data in Table 3 that the alkali content of this embodiment and the comparative example is less than 1%, which is an alkali-free accelerating setting agent. Compared with comparative samples 1 to 3, the embodiment has obvious advantages in dosage, compressive strength at different ages, etc. When the dosage is within the range of 6 to 7%, the setting time of cement paste and the strength of mortar can meet the requirements of GB / T35159-2017 "Accelerator for Shotcrete" for liquid alkali-free accelerating setting agent.

[0078] The room temperature synthetic liquid alkali-free quick-setting agent provided by this technical solution has the appearance of a milky white uniform liquid, is alkali-free, chlorine-free, fluorine-free, has no irritating odor, has a low dosage, sets quickly, does not corrode the human body, does not corrode steel bars, has good adaptability to various cements, overcomes the shortcomings of traditional alkaline quick-setting agents such as strong corrosion, poor workability, slow setting time, and large strength loss in the later stage, and has a simple production process, no need for heating, low raw material cost, and is suitable for large-scale production. It can be widely used in shotcrete construction and plugging of mine filling projects, shaft and tunnel projects, traffic tunnel projects, urban construction, water conservancy projects, etc., rapid construction of ground cement, emergency rescue, repair and reinforcement and other projects.

[0079] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A low temperature resistant fluorine-free and alkali-free liquid quick-setting agent, characterized in that: In terms of mass percentage, The invention comprises the following components: 55% to 60% aluminum sulfate, 0.5% to 1.0% suspension component, 1% to 3% antifreeze component, 2% to 3% organic complex component, 1.4% to 2.5% solubilizing component and 0.2% to 0.4% pH regulator, and the balance is water.

2. The low temperature resistant fluorine-free and alkali-free liquid quick-setting agent according to claim 1, characterized in that: The organic complex component is diethanolamine, the content of which is ≥99%, the aluminum sulfate is industrial-grade aluminum sulfate 18hydrate, the aluminum oxide content in the aluminum sulfate is ≥15.8%, and the aluminum sulfate is in the form of flakes.

3. The low temperature resistant fluorine-free and alkali-free liquid quick-setting agent according to claim 2, characterized in that: The antifreeze agent is prepared from urea and ethylene glycol in a mass ratio of (1-1): (1-0.5): (0.5-1).

4. The low temperature resistant fluorine-free and alkali-free liquid quick-setting agent according to claim 3, characterized in that: The suspending agent is forsterite powder, the solubilizing component is alkylphenol polyoxyethylene ether, and the pH regulator is glycolic acid or oxalic acid.

5. A method for preparing a low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent at room temperature, applied to the low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent as claimed in claim 4, characterized in that: The steps include: S1: Add water to a reaction container, add the solubilizing component to the reaction container, and continue stirring until it is completely dissolved; S2: slowly add the suspending agent into the container, continue stirring for 30 minutes until it is completely dissolved to form a suspension solution, then add 1 / 2 of the total amount of aluminum sulfate, and continue stirring for 30 minutes; S3: slowly dripping the organic complex component into a container, then adding 1 / 2 of the total amount of aluminum sulfate, and stirring continuously for 30 minutes; S4: slowly add the antifreeze component into the container, maintain the temperature and continue stirring for 30 minutes; S5: adding the pH adjusting component and stirring until the solution is clear, thereby obtaining the low temperature resistant fluorine-free and alkali-free liquid accelerating setting agent.

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