阅读说明：本技术 一种无碱速凝剂及其制备方法和应用 (Alkali-free accelerator and preparation method and application thereof ) 是由 李连震 王宏维 王英维 于 2020-05-18 设计创作，主要内容包括：本发明公开了一种无碱速凝剂及其制备方法。该无碱速凝剂的制备原料包括：偏铝酸钠、硫酸铝、氟硅酸、络合稳定剂和水。制备方法包括：步骤1、将偏铝酸钠与水进行混合,得到偏铝酸钠溶液；步骤2、将硫酸铝多次加入至所述偏铝酸钠溶液中,得到溶液I；步骤3、依次将氟硅酸和络合稳定剂加入至所述溶液I中。本发明的无碱速凝剂可以在较低掺量下即具有水泥凝结硬化快,后期强度能够满足工程施工要求等优点。(The invention discloses an alkali-free accelerator and a preparation method thereof. The alkali-free accelerator comprises the following raw materials: sodium metaaluminate, aluminum sulfate, fluosilicic acid, a complexing stabilizer and water. The preparation method comprises the following steps: step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution; step 2, adding aluminum sulfate into the sodium metaaluminate solution for multiple times to obtain a solution I; and 3, sequentially adding fluosilicic acid and a complexing stabilizer into the solution I. The alkali-free accelerator provided by the invention has the advantages that the cement can be quickly set and hardened at a lower mixing amount, the later strength can meet the engineering construction requirements, and the like.)

1. An alkali-free accelerator is prepared from the following raw materials: sodium metaaluminate, aluminum sulfate, fluosilicic acid, a complexing stabilizer and water.

2. The alkali-free accelerator as claimed in claim 1, wherein the sodium metaaluminate is used in an amount of 22 to 28 wt%, the aluminum sulfate is used in an amount of 35 to 42 wt%, the fluorosilicic acid is used in an amount of 25 to 33 wt%, the complexing stabilizer is used in an amount of 0.5 to 1 wt%, and the water is used in an amount of 3 to 5 wt%, based on the total weight of the alkali-free accelerator.

3. The alkali-free accelerator according to claim 1 or 2, wherein the complexing stabilizer is selected from one or more of hydroxymethyl cellulose, hydroxyethyl cellulose and EDTA.

4. A preparation method of an alkali-free accelerator comprises the following steps:

step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for multiple times to obtain a solution I;

and 3, sequentially adding fluosilicic acid and a complexing stabilizer into the solution I.

5. The method of claim 4, wherein the plurality of times in step 2 is 3 to 5 times.

6. A process according to claim 4 or 5, characterized in that the stirring is carried out for 20-30min after each addition of aluminium sulphate.

7. Process according to any one of claims 4 to 6, characterized in that the amount of aluminium sulphate added for the first time is between 10 and 25% by weight of the total amount of aluminium sulphate.

8. A method according to any one of claims 4 to 7, characterized in that the amount of aluminium sulphate added in the last pass is 10-25% by weight of the total amount of aluminium sulphate.

9. An alkali-free accelerator prepared by the method of any one of claims 4 to 8.

10. Use of an alkali-free accelerator according to any one of claims 1 to 3 and 9 or prepared according to the method of any one of claims 4 to 8 in infrastructure construction.

Technical Field

The invention relates to an alkali-free accelerator and a preparation method and application thereof.

Background

The accelerator is used as an additional concrete auxiliary agent, can effectively shorten the setting and hardening time of cement, has great influence on the setting time and the early strength of sprayed concrete, and has various types and different varieties in the current market. The alkali accelerator has high alkali content, strong corrosivity easily causes harm to the bodies of construction personnel, and alkali aggregate reaction is easily caused by the strong alkali property, so that the later strength of concrete is obviously reduced, the impermeability grade is reduced, the durability of the concrete is influenced, and the construction of engineering is not facilitated. However, the existing alkali-free accelerator mainly has the problems of large mixing amount, long coagulation time, high viscosity, easy generation of gel aggregation and thickening phenomenon, and incapability of meeting the requirements of engineering construction on later strength.

Disclosure of Invention

Aiming at the technical problems, the invention provides the alkali-free accelerator and the preparation method and the application thereof, and the alkali-free accelerator has the advantages that the cement can be quickly set and hardened under a lower mixing amount, the later strength can meet the engineering construction requirements and the like.

The invention provides an alkali-free accelerator, which is prepared from the following raw materials: sodium metaaluminate, aluminum sulfate, fluosilicic acid, a complexing stabilizer and water.

According to some embodiments of the alkali-free accelerator of the present invention, sodium metaaluminate is used in an amount of 22 to 28% by weight, based on the total weight of the alkali-free accelerator. Such as 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, and any value therebetween.

According to some embodiments of the alkali-free accelerator of the present invention, aluminum sulfate is used in an amount of 35 to 42 wt% based on the total weight of the alkali-free accelerator. Such as 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, and any value therebetween.

According to some embodiments of the alkali-free accelerator of the present invention, the fluorosilicic acid is used in an amount of 25 to 33% by weight, based on the total weight of the alkali-free accelerator. Such as 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, and any value therebetween.

According to some embodiments of the alkali-free accelerator of the present invention, the complexing stabilizer is used in an amount of 0.5 to 1% by weight, based on the total weight of the alkali-free accelerator. Such as 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, and any value therebetween.

According to some embodiments of the alkali-free accelerator of the present invention, water is used in an amount of 3 to 5% by weight, based on the total weight of the alkali-free accelerator. Such as 3 wt%, 4 wt%, 5 wt%, and any value therebetween. In the present invention, the water may be deionized water.

According to some embodiments of the alkali-free accelerator of the invention, the complexing stabilizer is selected from one or more of hydroxymethylcellulose, hydroxyethylcellulose and EDTA (ethylenediaminetetraacetic acid).

The invention provides a preparation method of an alkali-free accelerator, which comprises the following steps:

step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for multiple times to obtain a solution I;

and 3, sequentially adding fluosilicic acid and a complexing stabilizer into the solution I.

According to some embodiments of the preparation method of the present invention, the plurality of times in the step 2 is 3 to 5 times.

According to some embodiments of the preparation method of the present invention, the stirring is performed for 20-30min after each addition of aluminum sulfate.

According to some embodiments of the process of the present invention, the first addition of aluminum sulfate is 10 to 25% by weight of the total amount of aluminum sulfate. Such as 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, and any value therebetween.

According to some embodiments of the process of the present invention, the amount of aluminum sulfate added in the last time is 10 to 25% by weight of the total amount of aluminum sulfate. Such as 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, and any value therebetween.

The sodium metaaluminate is used in 22-28 wt% based on the total weight of the alkali-free setting accelerator. Such as 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, and any value therebetween.

According to some embodiments of the preparation method of the present invention, the aluminum sulfate is used in an amount of 35 to 42 wt% based on the total weight of the alkali-free accelerator. Such as 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, and any value therebetween.

According to some embodiments of the preparation method of the present invention, the fluorosilicic acid is used in an amount of 25 to 33% by weight, based on the total weight of the alkali-free accelerator. Such as 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, and any value therebetween.

According to some embodiments of the method of preparing the present invention, the complexing stabilizer is used in an amount of 0.5 to 1% by weight, based on the total weight of the alkali-free accelerator. Such as 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, and any value therebetween.

According to some embodiments of the preparation method of the present invention, the water is used in an amount of 3 to 5% by weight, based on the total weight of the alkali-free accelerator. Such as 3 wt%, 4 wt%, 5 wt%, and any value therebetween. In the present invention, the water may be deionized water.

According to some embodiments of the method of making of the present invention, the complexing stabilizer is selected from one or more of hydroxymethyl cellulose, hydroxyethyl cellulose and EDTA.

In a third aspect, the invention provides an alkali-free accelerator prepared by the above method.

In a fourth aspect, the invention provides the use of the alkali-free accelerator or the alkali-free accelerator prepared according to the method in the construction of foundation engineering.

Compared with the prior art, the invention has the beneficial effects that:

(1) compared with the existing alkali-free accelerator, the accelerator provided by the invention has the advantages that the cement can be quickly set and hardened under a lower mixing amount, the later strength can meet the engineering construction requirements, and the like;

(2) the alkali-free accelerator provided by the invention has the advantages of no corrosion, good long-term storage stability, low viscosity, easiness in construction and the like.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention easier to understand, the present invention will be described in further detail with reference to the following examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[ example 1 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 3 times to obtain a solution I; wherein, after adding aluminum sulfate each time, stirring for 20min, the first time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate, the second time of adding aluminum sulfate accounts for 50 wt% of the total amount of aluminum sulfate, and the last time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose (complexing stabilizer) into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 22 weight percent, the dosage of aluminum sulfate is 40 weight percent, the dosage of fluosilicic acid is 33 weight percent, the dosage of complexing stabilizer is 1 weight percent, and the dosage of water is 4 weight percent.

[ example 2 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 4 times to obtain a solution I, stirring for 20min after adding aluminum sulfate each time, wherein the amount of aluminum sulfate added for the first time is 10 wt% of the total amount of aluminum sulfate, the amount of aluminum sulfate added for the second time and the third time is 40 wt% of the total amount of aluminum sulfate, and the amount of aluminum sulfate added for the last time is 10 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 22 weight percent, the dosage of aluminum sulfate is 40 weight percent, the dosage of fluosilicic acid is 33 weight percent, the dosage of complexing stabilizer is 1 weight percent, and the dosage of water is 4 weight percent.

[ example 3 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 5 times to obtain a solution I; wherein, after adding aluminum sulfate each time, stirring for 20min, the amount of aluminum sulfate added for the first time is 10 wt% of the total amount of aluminum sulfate, the amount of aluminum sulfate added for the second time is 30 wt% of the total amount of aluminum sulfate, the amount of aluminum sulfate added for the third time is 30 wt% of the total amount of aluminum sulfate, the amount of aluminum sulfate added for the fourth time is 20 wt% of the total amount of aluminum sulfate, and the amount of aluminum sulfate added for the last time is 10 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 22 weight percent, the dosage of aluminum sulfate is 40 weight percent, the dosage of fluosilicic acid is 33 weight percent, the dosage of complexing stabilizer is 1 weight percent, and the dosage of water is 4 weight percent.

[ example 4 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 3 times to obtain a solution I; wherein, after adding aluminum sulfate each time, stirring for 30min, the first time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate, the second time of adding aluminum sulfate accounts for 50 wt% of the total amount of aluminum sulfate, and the last time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxyethyl cellulose (complexing stabilizer) into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 28 weight percent, the dosage of aluminum sulfate is 39 weight percent, the dosage of fluosilicic acid is 27.5 weight percent, the dosage of complex stabilizer is 0.5 weight percent, and the dosage of water is 5 weight percent.

[ example 5 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 3 times to obtain a solution I, and stirring for 20min after adding aluminum sulfate each time, wherein the amount of aluminum sulfate added for the first time is 35 wt% of the total amount of aluminum sulfate, the amount of aluminum sulfate added for the second time is 45 wt% of the total amount of aluminum sulfate, and the amount of aluminum sulfate added for the last time is 20 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 22 weight percent, the dosage of aluminum sulfate is 40 weight percent, the dosage of fluosilicic acid is 33 weight percent, the dosage of complexing stabilizer is 1 weight percent, and the dosage of water is 4 weight percent.

[ example 6 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 3 times to obtain a solution I, and stirring for 20min after adding aluminum sulfate each time, wherein the amount of the added aluminum sulfate for the first time is 20 wt% of the total amount of the aluminum sulfate, the amount of the added aluminum sulfate for the second time is 45 wt% of the total amount of the aluminum sulfate, and the amount of the added aluminum sulfate for the last time is 35 wt% of the total amount of the aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 22 weight percent, the dosage of aluminum sulfate is 40 weight percent, the dosage of fluosilicic acid is 33 weight percent, the dosage of complexing stabilizer is 1 weight percent, and the dosage of water is 4 weight percent.

[ example 7 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution to obtain a solution I;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 22 weight percent, the dosage of aluminum sulfate is 40 weight percent, the dosage of fluosilicic acid is 33 weight percent, the dosage of complexing stabilizer is 1 weight percent, and the dosage of water is 4 weight percent.

[ example 8 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 3 times to obtain a solution I; wherein, after adding aluminum sulfate each time, stirring for 20min, the first time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate, the second time of adding aluminum sulfate accounts for 50 wt% of the total amount of aluminum sulfate, and the last time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 18 weight percent, the dosage of aluminum sulfate is 50 weight percent, the dosage of fluosilicic acid is 20 weight percent, the dosage of complexing stabilizer is 2 weight percent, and the dosage of water is 10 weight percent.

[ example 9 ]

Step 1, mixing sodium metaaluminate with water to obtain a sodium metaaluminate solution;

step 2, adding aluminum sulfate into the sodium metaaluminate solution for 3 times to obtain a solution I; wherein, after adding aluminum sulfate each time, stirring for 20min, the first time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate, the second time of adding aluminum sulfate accounts for 50 wt% of the total amount of aluminum sulfate, and the last time of adding aluminum sulfate accounts for 25 wt% of the total amount of aluminum sulfate;

step 3, sequentially adding fluosilicic acid and hydroxymethyl cellulose into the solution I;

wherein, based on the total weight of the alkali-free accelerator, the dosage of sodium metaaluminate is 35 weight percent, the dosage of aluminum sulfate is 30 weight percent, the dosage of fluosilicic acid is 32.8 weight percent, the dosage of complex stabilizer is 0.2 weight percent, and the dosage of water is 2 weight percent.

Comparative example 1

The procedure of example 1 was followed except that no complexing stabilizer was used.

Comparative example 2

The procedure of example 1 was followed except that fluosilicic acid was not used.

Comparative example 3

The alkali-free accelerator is commercially available from Jiangsu Subo New Material Co., Ltd under the brand name

[ test example 1 ]

The performance indexes of the mortar prepared by respectively adopting the liquid accelerating agents of examples 1-9 and comparative examples 1-3 are detected according to the method of national standard JC477-2005 accelerator special for sprayed concrete, and the specific detection results are shown in Table 1. The preparation method of the mortar comprises the following steps of 900g of cement, 1350g of standard sand and 450g of water, wherein the type of the cement is P.042.5.

TABLE 1

As can be seen from the above examples and comparative examples, the alkali-free accelerator provided by the invention has the advantages that the cement can be quickly set and hardened at a low mixing amount, the later strength can meet the engineering construction requirements, and the like.

In addition, comparing examples 1-4 and example 5 (the first addition of aluminum sulfate is 35 wt% of the total amount of aluminum sulfate), example 6 (the last addition of aluminum sulfate is 35 wt% of the total amount of aluminum sulfate), example 7 (the aluminum sulfate is added in one time), example 8 and example 9 (the use amount of each substance is not in the preferred range of the invention), the alkali-free accelerator prepared by the preferred method of the invention has better effect.

What has been described above is merely a preferred example of the present invention. It should be noted that other equivalent variations and modifications can be made by those skilled in the art based on the technical teaching provided by the present invention, and the protection scope of the present invention should be considered.