Powdered alkali-free accelerator for water-rich construction environment as well as preparation method and application of powdery alkali-free accelerator

Abstract

The invention discloses a powdered alkali-free accelerator for a water-rich construction environment. The powdered alkali-free accelerator is prepared from the following components in parts by weight: 50-55 parts of modified aluminum sulfate, 3-5 parts of meta-aluminate, 5-11 parts of a complexing agent, 0.6-1.3 parts of a stabilizer and 0-1 part of a neutralizer, wherein the modified aluminum sulfate is composed of 80-90 parts by weight of liquid aluminum sulfate and 7-10 parts by weight of protonated alkylol amine, and the protonated alkylol amine is prepared from 30-50 parts by weight of alkylol amine and 10-55 parts by weight of a chelating agent. According to the powdered alkali-free accelerator, the alkylol amine substances in the raw materials are subjected to protonation treatment and are used for modifying the aluminum sulfate, so that the utilization rate of the aluminum sulfate is improved; the curing of the alcamines is realized, and the pulverization of the liquid accelerator is also better realized. The finished powdered alkali-free accelerator is convenient to weigh, store and transport, the production cost is reduced, and the quality and stability of the product are improved.

Description

Technical Field

[0001] The invention relates to the technical field of building material admixtures, in particular to a high-performance powdered alkali-free quick-setting agent for a water-rich construction environment and a preparation method and application thereof. Background Art

[0002] Accelerator is one of the key raw materials for the coagulation and hardening of shotcrete. Its main function is to accelerate the coagulation and hardening speed of shotcrete, reduce rebound loss, prevent shotcrete from falling off due to gravity, increase the thickness of one shot and shorten the interval time between shot layers. At present, the accelerators used in the prior art are mainly liquid alkali / alkali-free accelerators. Although this liquid accelerator is easy to use and has a good effect, it also has significant defects: 1. The product quality is large, resulting in high production and transportation costs; 2. The product stability is poor and there are many transportation safety hazards. Therefore: How to reasonably improve the existing liquid accelerator to improve its product quality, reduce production and transportation costs, and improve product competitiveness is of great significance.

[0003] Generally, among the various raw materials used in the preparation of liquid accelerators, the main liquid materials are alcoholamines. The methods used to powderize alcoholamines are mainly as follows: 1. The overall accelerator is powderized by using an adsorbent to adsorb alcoholamines, but this method has high requirements on the particle size of the raw materials, and the process is complicated and the production cost is high; 2. Through chemical reactions, the alcoholamines in the raw materials are compounded with compounds to prepare solid alcoholamines, but the implementation process of this method involves separation and purification, and the generated solid alcoholamines contain water-insoluble substances, so it cannot achieve good quick-setting function during the construction process. Therefore, it is not suitable for the powderization of liquid accelerators; 3. By changing the formula of the accelerator to select organic substances to replace the alcoholamines in the raw materials, the accelerator prepared by this method is lower in performance than the accelerator containing alcoholamines, the use effect is poor, and the cost of raw materials is also correspondingly high.

[0004] Therefore, how to develop and prepare a simple and low-cost method to achieve the powderization of the accelerating setting agent is of great significance for improving the product quality of the accelerating setting agent and reducing the production and transportation costs. Summary of the invention

[0005] The technical purpose of the present invention is to provide a powdered alkali-free quick-setting agent for water-rich construction environments. The technical solution of the present invention is to protonate the alcoholamine substances in the raw materials and use them to modify aluminum sulfate, thereby achieving the solidification of the alcoholamine substances and better achieving the powderization of the liquid quick-setting agent. The finished powdered alkali-free quick-setting agent is easy to weigh, store and transport, reducing the production cost and improving the quality and stability of the product.

[0006] To achieve the above object, the technical scheme adopted by the present invention is: a powdered alkali-free quick-setting agent for a water-rich construction environment is composed of the following components in parts by weight: 50-55 parts of modified aluminum sulfate, 3-5 parts of metaaluminate, 5-11 parts of a complexing agent, 0.6-1.3 parts of a stabilizer and 0-1 part of a neutralizer; The modified aluminum sulfate is composed of 80-90 parts by weight of liquid aluminum sulfate and 7-10 parts by weight of protonated alcoholamine, and the protonated alcoholamine is made of 30-50 parts by weight of alcoholamine and 10-55 parts by weight of chelating agent.

[0007] Furthermore, the liquid aluminum sulfate is aluminum sulfate 18hydrate.

[0008] Furthermore, the alcoholamine is at least one of diethanolamine, triethanolamine and triisopropanolamine.

[0009] Furthermore, the chelating agent is at least one of EDTA, tartaric acid and citric acid.

[0010] Furthermore, the preparation method of the modified aluminum sulfate is: (1) Weighing an alcohol amine and a chelating agent in a mass ratio of (30-50):(10-55) respectively, placing them at a temperature of 100-150° C. and stirring them for 1-2 hours to obtain a transparent liquid protonated alcohol amine; (2) According to the mass ratio of protonated alcohol amine to liquid aluminum sulfate of (7-10): (80-90), liquid aluminum sulfate is weighed and heated to 120-40° C., and then the protonated alcohol amine prepared in step (1) is added to the liquid aluminum sulfate, and after being fully mixed, the mixture is placed on a plate belt machine for cooling and crystallization, and then sliced ​​and crushed to obtain modified aluminum sulfate.

[0011] Furthermore, the aluminate is one or both of potassium aluminate and sodium aluminate; and the complexing agent is at least one of amino acid, oxalic acid and citric acid.

[0012] Furthermore, the stabilizer is at least one of sepiolite, magnesium aluminum silicate, water-based organic bentonite and aluminum sol.

[0013] Furthermore, the neutralizing agent is one or both of magnesium oxide and magnesium hydroxide.

[0014] The preparation method of powdered alkali-free quick-setting agent for water-rich construction environment is as follows: modified aluminum sulfate, metaaluminate, chelating agent, stabilizer and neutralizing agent are respectively weighed according to parts by weight, and after being fully mixed in a pulverizer, a finished powdered alkali-free quick-setting agent is obtained.

[0015] The application of powdered alkali-free accelerator in the preparation of concrete is to mix the powdered alkali-free accelerator with water in a mass ratio of 1: (0.9~1.1), and after being fully emulsified and mixed by an emulsifying pump, a liquid accelerator is obtained and mixed in concrete for use.

[0016] Beneficial effects: 1. The powdered alkali-free quick-setting agent for water-rich construction environment of the present invention is composed of raw materials with specific contents and components. It not only realizes the effective solidification and safe transportation of the alkali-free substances, but also realizes the effective modification of the quick-setting main material aluminum sulfate in the quick-setting agent by protonating the large volume and mass of the alkali-free quick-setting agent, so that the powdered alkali-free quick-setting agent after compounding has significant advantages such as no fluorine, no alkali, no chlorine, good stability, high early strength, and strong adaptability. At the same time, the powderization of the liquid quick-setting agent is convenient for weighing, storage and transportation, so the transportation cost is reduced, the stability of the product is improved, and it is basically applicable to the powderization of various liquid quick-setting agents. Therefore, it has a wide range of applications, strong product competitiveness, can further increase the advantages of the enterprise, and is conducive to foreign exports to more countries and regions.

[0017] 2. The powdered alkali-free quick-setting agent for water-rich construction environment of the present invention is composed of modified aluminum sulfate, metaaluminate, chelating agent, stabilizer and neutralizer in terms of raw material components. The modified aluminum sulfate in the components is composed of liquid aluminum sulfate and protonated alcohol amine. In the preparation process of protonated alcohol amine, the present invention realizes the protonation of alcohol amine by combining the lone pair of electrons of nitrogen atoms in alcohol amine with free hydrogen in chelating agent under high temperature environment. In the preparation process of modified aluminum sulfate, the protonated alcohol amine in transparent solution is added to liquid aluminum sulfate at a relatively high temperature, so that the aluminum in aluminum sulfate is combined with the protonated alcohol amine, and the chelating agent and aluminum sulfate itself are used as "solidification carriers" to achieve the modification of aluminum sulfate and the solidification of alcohol amine substances. The prepared modified aluminum sulfate does not have the wall sticking phenomenon during the pulverization process, and it is known through performance test comparison that the alcohol amine substances in the modified aluminum sulfate can play the same role in the quick-setting agent compared with the liquid alcohol amine substances used alone, which shows that its structure and properties have not changed. The modified aluminum sulfate can promote the powderization of liquid accelerating agent, reduce transportation cost and improve transportation safety.

[0018] 3. The powdered alkali-free quick-setting agent for water-rich construction environment of the present invention improves the production process in the process of preparing liquid quick-setting agent for industrial production and application, adds an emulsifying pump for continuous emulsification-dispersion to prepare liquid quick-setting agent, increases the content of effective ingredients, promotes better uniform dispersion of quick-setting components in the quick-setting agent, obtains liquid quick-setting agent with excellent performance, has good use effect, has the advantages of high early strength, is not easy to fall off during construction in water-rich environment, has fast coagulation and hardening speed, has little rebound loss, etc., and has a wide range of adaptability. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict, and the following embodiments cannot be used as a limitation on the protection scope of the present invention.

[0020] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, are all of the specifications required for conventional experiments in the art.

[0021] Based on the various defects and deficiencies of liquid accelerators in the prior art, the present invention protonates the alcoholamine substances in the aluminum sulfate type accelerator, prepares modified aluminum sulfate on this basis, and grinds it together with other raw materials in the accelerator to obtain a powdered alkali-free accelerator. The powdered alkali-free accelerator is convenient for transportation, reduces transportation costs, further increases the advantages of enterprises, and is conducive to foreign exports to more countries and regions. The specific technical scheme is as follows: The powdered alkali-free quick-setting agent for water-rich construction environment is composed of the following components in parts by weight: 50-55 parts of modified aluminum sulfate, 3-5 parts of metaaluminate, 5-11 parts of complexing agent, 0.6-1.3 parts of stabilizer and 0-1 part of neutralizer; The modified aluminum sulfate is composed of 80-90 parts by weight of liquid aluminum sulfate and 7-10 parts by weight of protonated alcoholamine, and the protonated alcoholamine is made of 30-50 parts by weight of alcoholamine and 10-55 parts by weight of chelating agent.

[0022] The liquid aluminum sulfate is aluminum sulfate 18hydrate; the alcohol amine is at least one of diethanolamine, triethanolamine and triisopropanolamine; and the chelating agent is at least one of EDTA, tartaric acid and citric acid.

[0023] The preparation method of the modified aluminum sulfate is: (1) Weighing an alcohol amine and a chelating agent in a mass ratio of (30-50):(10-55) respectively, placing them at a temperature of 100-150° C. and stirring them for 1-2 hours to obtain a transparent liquid protonated alcohol amine; (2) According to the mass ratio of protonated alcohol amine to liquid aluminum sulfate of (7-10): (80-90), liquid aluminum sulfate is weighed and heated to 120-40° C., and then the protonated alcohol amine prepared in step (1) is added to the liquid aluminum sulfate, and after being fully mixed, the mixture is placed on a plate belt machine for cooling and crystallization, and then sliced ​​and crushed to obtain modified aluminum sulfate.

[0024] The aluminate is one or both of potassium aluminate and sodium aluminate; the complexing agent is at least one of amino acid, oxalic acid and citric acid; the stabilizer is at least one of sepiolite, magnesium aluminum silicate, water-based organic bentonite and aluminum sol; the neutralizer is one or both of magnesium oxide and magnesium hydroxide.

[0025] The preparation method of powdered alkali-free quick-setting agent for water-rich construction environment is as follows: modified aluminum sulfate, metaaluminate, chelating agent, stabilizer and neutralizing agent are respectively weighed according to parts by weight, and after being fully mixed in a pulverizer, a finished powdered alkali-free quick-setting agent is obtained.

[0026] The application of powdered alkali-free accelerator in the preparation of concrete is to mix the powdered alkali-free accelerator with water in a mass ratio of 1: (0.9~1.1), and after being fully emulsified and mixed by an emulsifying pump, a liquid accelerator is obtained and mixed in concrete for use.

[0027] The powdered alkali-free quick-setting agent prepared by the invention can be used in a water-rich construction environment with good use effect, and has the advantages of being fluorine-free, alkali-free, chlorine-free, good stability, high early strength, strong adaptability, and the like.

[0028] Example 1 The powdered alkali-free quick-setting agent for water-rich construction environment of this embodiment has a specific preparation method as follows: 1. Preparation of protonated alcoholamine: 500g of diethanolamine and 100g of EDTA are kept at 120°C for 1h to obtain a transparent solution, which is the protonated alcoholamine.

[0029] 2. Preparation of modified aluminum sulfate: Take 1000g of liquid aluminum sulfate, add 100g of protonated alcoholamine, mix well, cool at room temperature, and grind with a grinder to obtain powdered modified aluminum sulfate.

[0030] 3. Preparation of powdered alkali-free accelerator: weigh 550g of modified aluminum sulfate, 50g of sodium aluminate, 4g of magnesium hydroxide, 100g of citric acid, and 6g of magnesium aluminum silicate, and mix them evenly using a pulverizer. When using, add water to 1000g, and under the emulsification action of a stirring-emulsifying pump, a liquid high-performance powdered alkali-free accelerator can be obtained in 40 minutes.

[0031] Example 2 The powdered alkali-free quick-setting agent for water-rich construction environment of this embodiment has a specific preparation method as follows: 1. Preparation of protonated alcoholamine: same as Example 1.

[0032] 2. Preparation of modified aluminum sulfate: same as Example 1.

[0033] 3. Preparation of powdered alkali-free accelerator: weigh 620g of modified aluminum sulfate, 30g of potassium aluminate, 4g of magnesium hydroxide, 60g of amino acid, and 6g of magnesium aluminum silicate, and mix them evenly using a pulverizer. When using, add water to 1000g, and under the emulsification action of a stirring-emulsifying pump, a liquid high-performance powdered alkali-free accelerator can be obtained in 40 minutes.

[0034] Example 3 The powdered alkali-free quick-setting agent for water-rich construction environment of this embodiment has a specific preparation method as follows: 1. Preparation of protonated alcoholamine: 500g triethanolamine and 100g EDTA are kept at 120℃ for 1h to obtain a transparent solution, which is the protonated alcoholamine.

[0035] 2. Preparation of modified aluminum sulfate: Take 1000g of liquid aluminum sulfate, add 180g of protonated alcoholamine, mix well, cool at room temperature, and grind with a grinder to obtain powdered modified aluminum sulfate.

[0036] 3. Preparation of powdered alkali-free accelerator: weigh 620g of modified aluminum sulfate, 30g of sodium aluminate, 60g of amino acid, 6g of sepiolite, and 4g of magnesium oxide, and mix them evenly using a pulverizer. When using, add water to 1000g, and under the emulsification action of a stirring-emulsifying pump, a liquid high-performance powdered alkali-free accelerator can be obtained in 40 minutes.

[0037] The above reagents can be purchased from the market. The specific implementation scheme of the present invention is described in detail below.

[0038] Several examples are given below to verify the performance of the deflocculant of the present invention. The specific proportion (mass percentage) of each example is shown in Table 1 below.

[0039] With reference to GB / T 35159-2017 and Q / CR 807-2020, the setting time and early mortar strength of the cement paste in the above embodiment were verified using benchmark cement, and the data and conclusions are shown in Table 2 below.

[0040] From the above results, it can be concluded that the three embodiments can meet the standard requirements (pH ≥ 2, initial setting ≤ 5min; final setting ≤ 12min; 6 h mortar compressive strength ≥ 1 MPa; 1d mortar compressive strength ≥ 10 MPa). At the dosage of 5~7%, the benchmark cement, Tongli cement, Tianrui cement, and the embodiment indicators are better than the control example data.

[0041] The stability of the above-mentioned accelerator was tested with reference to GB / T 35159-2017 Accelerators for Shotcrete. Considering the construction conditions during its actual use, its low-temperature stability was tested: From the above results, it can be concluded that the embodiment still has good stability in a low temperature environment.

[0042] Although the present application has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that various changes may be made without departing from the true spirit and scope of the present application. In addition, various changes may be made to the subject, spirit and scope of the present application to adapt to specific situations, materials, material combinations and methods. All of these changes are included within the scope of the claims of the present application.

[0043] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. Powdered alkali-free quick-setting agent for water-rich construction environment, characterized in that: The invention is composed of the following components in parts by weight: 50-55 parts of modified aluminum sulfate, 3-5 parts of metaaluminate, 5-11 parts of complexing agent, 0.6-1.3 parts of stabilizer and 0-1 part of neutralizing agent; The modified aluminum sulfate is composed of 80-90 parts by weight of liquid aluminum sulfate and 7-10 parts by weight of protonated alcoholamine, and the protonated alcoholamine is made of 30-50 parts by weight of alcoholamine and 10-55 parts by weight of chelating agent.

2. The powdered alkali-free quick-setting agent for water-rich construction environment according to claim 1, characterized in that: The liquid aluminum sulfate is aluminum sulfate 18hydrate.

3. The powdered alkali-free quick-setting agent for water-rich construction environment according to claim 1, characterized in that: The alcohol amine is at least one of diethanolamine, triethanolamine and triisopropanolamine.

4. The powdered alkali-free quick-setting agent for water-rich construction environment according to claim 1, characterized in that: The chelating agent is at least one of EDTA, tartaric acid and citric acid.

5. The powdered alkali-free quick-setting agent for water-rich construction environment according to any one of claims 1 to 4, characterized in that: The preparation method of the modified aluminum sulfate is: (1) Weighing an alcohol amine and a chelating agent in a mass ratio of (30-50):(10-55) respectively, placing them at a temperature of 100-150° C. and stirring them for 1-2 hours to obtain a transparent liquid protonated alcohol amine; (2) According to the mass ratio of protonated alcohol amine to liquid aluminum sulfate of (7-10): (80-90), liquid aluminum sulfate is weighed and heated to 120-40° C., and then the protonated alcohol amine prepared in step (1) is added to the liquid aluminum sulfate, and after being fully mixed, the mixture is placed on a plate belt machine for cooling and crystallization, and then sliced ​​and crushed to obtain modified aluminum sulfate.

6. The powdered alkali-free quick-setting agent for water-rich construction environment according to claim 1, characterized in that: The aluminate is one or both of potassium aluminate and sodium aluminate; the complexing agent is at least one of amino acid, oxalic acid and citric acid.

7. The powdered alkali-free quick-setting agent for water-rich construction environment according to claim 1, characterized in that: The stabilizer is at least one of sepiolite, magnesium aluminum silicate, water-based organic bentonite and aluminum sol.

8. The powdered alkali-free quick-setting agent for water-rich construction environment according to claim 1, characterized in that: The neutralizing agent is one or both of magnesium oxide and magnesium hydroxide.

9. The method for preparing a powdered alkali-free quick-setting agent for a water-rich construction environment according to claim 1, characterized in that: The modified aluminum sulfate, aluminate, chelating agent, stabilizer and neutralizing agent are respectively weighed in parts by weight and fully mixed in a pulverizer to obtain a finished powdered alkali-free accelerating setting agent.

10. The use of the powdered alkali-free quick-setting agent according to claim 1 in preparing concrete, characterized in that: Take powdered alkali-free quick-setting agent and water in a mass ratio of 1: (0.9-1.1), stir and mix them, and after sufficient emulsification and mixing by an emulsifying pump, a liquid quick-setting agent is obtained and mixed in concrete for use.

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