Preparation method and application of high-performance powdery alkali-free accelerator core master batch

Abstract

The invention relates to the technical field of concrete admixture accelerators, in particular to an alkali-free powdery accelerator core master batch, and particularly relates to a preparation method and application of the high-performance powdery alkali-free accelerator core master batch. The anti-caking agent comprises the following raw materials in parts by weight: 50-75 parts of a coagulation accelerating component, 5-15 parts of fluosilicate, 10-20 parts of a fluorine-aluminum complex, 5-10 parts of an early strength component, 1-2 parts of a suspension component, 1-3 parts of a pH adjusting component and 0.5-1 part of an anti-caking component, according to the high-performance powdery alkali-free accelerator core master batch disclosed by the invention, aluminum ions are introduced to the greatest extent, and fluorine in the high-performance powdery alkali-free accelerator core master batch is also increased, so that combination of main effective components is realized, and the performance of a powdery alkali-free accelerator is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of concrete admixture accelerating agents, in particular to an alkali-free powdered accelerating agent core masterbatch, and specifically to a preparation method and application of a high-performance powdered alkali-free accelerating agent core masterbatch. Background Art

[0002] In today's rapid development of the construction industry, every progress in concrete technology has attracted much attention. Alkali-free accelerator, as a kind of concrete additive, plays an irreplaceable role in tunnels, bridges, underground projects and other occasions where rapid hardening is required due to its unique performance advantages. The current liquid alkali-free accelerator products have poor stability and are not suitable for long-term storage; crystallization and thickening are prone to occur in low temperature environments, which can seriously affect normal use; the most common problem is that the packaging and transportation costs are too high. This defect leads to a small radiation range of liquid alkali-free accelerator products, which seriously affects the use and promotion of alkali-free accelerators.

[0003] In order to overcome the defects of alkali-free liquid accelerators, the preparation technology of alkali-free accelerators is constantly innovating, especially the relevant patents for the preparation of powdered alkali-free accelerators are emerging in an endless stream, but their use and compounding effects are mixed.

[0004] Patent CN202410313652.4 discloses a powdered alkali-free quick-setting agent and a preparation method thereof, wherein the main preparation method is to weigh magnesium aluminum hydrotalcite, aluminum sulfate, calcium silicate hydrate, early strength component, water retention component, accelerating coagulant component and water absorption component in parts by weight and mix them evenly. This technical solution is easy to operate, but the powdered quick-setting agent contains a large amount of water-insoluble substances, and its water solubility is poor during use, and there are many problems in terms of performance and stability.

[0005] Patent CN202211004195.8 discloses a method for preparing a dry powder accelerating setting agent using fluorosilicone slag. The main technical scheme of the patent is that, by weight, it contains 1-5 parts of fluorosilicone slag, 0.5-2 parts of sodium salt, 1-4 parts of aluminum-containing components, 40-55 parts of aluminum sulfate and 35-55 parts of water. First, the solution is wet-milled to obtain different mother liquors, and then the mother liquor and aluminum sulfate solution are mixed for reaction, and finally the water is dried and pulverized to obtain the dry powder accelerating setting agent. A large amount of energy will be consumed when the water is dried, which greatly increases the energy cost.

[0006] Patent CN202110721344.1 discloses a powdered alkali-free accelerator and its preparation method, use method and application. The patented technical solution evenly mixes its raw materials, aluminum sulfate, magnesium fluorosilicate, adsorbent, alcohol amine, early strength agent, stabilizer and neutralizer to obtain the powdered alkali-free accelerator. Aluminum sulfate in a conventional state is mostly granular or sandy, and its fineness is difficult to meet the requirements of GB / T35159-2017 "Alkali-free Accelerator for Shotcrete".

[0007] Patent CN202310958525.5 discloses a powdered alkali-free quick-setting agent and a preparation method thereof. The patented technical solution mainly adds a coagulant, a fluoride, and a complexing agent to a grinder for grinding, then adds a pH regulator, a viscosity regulator, and a stabilizer for grinding, and adds the ground materials and modified nano-ettringite, an early strength agent, and a defoaming agent to a mixer for mixing to obtain the powdered alkali-free quick-setting agent. Aluminum sulfate in a conventional state is 18 crystal water aluminum sulfate, which is easily dissolved by the heat generated by grinding during the mixing and grinding process, resulting in agglomeration, and thus a powdered quick-setting agent cannot be obtained.

[0008] Based on the above-mentioned difficult-to-solve problems of powdered alkali-free accelerators, it is known from the search of existing patents and literature that there is currently no powdered alkali-free accelerator that can achieve efficient compounding and meet the characteristics of different cement adaptability on site. Therefore, preparing a high-performance powdered alkali-free accelerator core masterbatch to achieve product diversification to meet different application needs will have a better application prospect. Summary of the invention

[0009] The first object of the present invention is to provide a method for preparing a core masterbatch of a high-performance powdered alkali-free quick-setting agent, which has the characteristics of fast dispersion speed, stable storage and excellent performance. It is convenient for storage, transportation and application in low-temperature areas, especially for overseas trade and Sichuan-Tibet region, and solves the defects of using liquid quick-setting agents that are not suitable for long-term storage, and the high packaging and transportation costs resulting in a small radiation range.

[0010] The second object of the present invention is to provide an application of a high-performance powdered alkali-free quick-setting agent core masterbatch. The high-performance powdered alkali-free quick-setting agent of the present invention has good water solubility and can be compounded into liquid products with different solid contents by adding water according to the different adaptability of cement at the site of use, thereby adding more adjustment options to the on-site compounding.

[0011] To achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0012] A high-performance powdered alkali-free quick-setting agent core masterbatch, the raw materials of which include, by weight, 50-75 parts of a coagulant component, 5-15 parts of fluorosilicate, 10-20 parts of a fluorine-aluminum complex, 5-10 parts of an early strength component, 1-2 parts of a suspension component, 1-3 parts of a pH regulating component, and 0.5-1 part of an anti-caking component.

[0013] Preferably, the coagulant-accelerating component is at least one of industrial-grade aluminum sulfate 18hydrate and polyaluminum sulfate, which is self-made by the enterprise and has a moisture content of less than 5%.

[0014] Preferably, the fluorosilicate is at least one of magnesium fluorosilicate, zinc fluorosilicate, sodium fluorosilicate and potassium fluorosilicate.

[0015] Preferably, the fluoroaluminum complex is a stable mixture of high aluminum and high fluorine which is self-made by the enterprise and has good water solubility.

[0016] Preferably, the early strength component is at least one of lithium sulfate, zirconium sulfate, magnesium sulfate, sodium sulfate and solid alcohol amine.

[0017] Preferably, the suspended component is at least one of sepiolite, magnesium aluminum silicate, bentonite, attapulgite or magnesium aluminum hydrotalcite.

[0018] Preferably, the pH adjusting component is at least one of anhydrous sodium hydroxide, anhydrous calcium hydroxide and anhydrous calcium carbonate.

[0019] Preferably, the anti-caking component is at least one of microcrystalline cellulose, talc and sodium hydroxymethyl cellulose.

[0020] A method for preparing a high-performance powdered alkali-free accelerating agent core masterbatch comprises the following steps:

[0021] 1) Put a certain amount of accelerating coagulant component into a dryer, dry at 90-105°C for 3-5h, take it out and grind it in a grinder to obtain a powder with a moisture content of less than 5% and a fineness of 100-200 mesh;

[0022] 2) The fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 70-90°C for 1-2 hours, and cooled to room temperature for use;

[0023] 3) The stabilizers obtained in the above steps 1) and 2) are mixed uniformly according to the proportion to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch.

[0024] The application of a high-performance powdered alkali-free accelerator core masterbatch is used in shotcrete, which meets the dosage requirements of the national standard GB / T35159-2017 "Alkali-free accelerator for shotcrete", and the dosage range is 6-9% of the cement mass.

[0025] The present invention has at least one of the following beneficial effects:

[0026] 1) The high-performance powdered alkali-free accelerating setting agent core masterbatch introduces aluminum ions to the greatest extent and increases the fluorine therein, thereby achieving the combination of the main effective components and greatly improving the performance of the powdered alkali-free accelerating setting agent.

[0027] 2) The high-performance powdered alkali-free quick-setting agent core masterbatch has good water solubility. It can be compounded into liquid products with different solid contents by adding water according to the adaptability of different cements at the use site. If there are special requirements for cost and strength, multiple components such as aluminum sulfate and mother liquor can be introduced into the compounding, which not only improves the product performance, but also reduces the compounding cost to a certain extent, and adds more adjustment options for on-site compounding.

[0028] 3) The high-performance powdered alkali-free quick-setting agent core masterbatch has greatly reduced packaging and transportation costs. Each ton of the masterbatch can be added with water or other accelerating components to prepare 1.8 to 6 tons of alkali-free liquid quick-setting agent products, saving 60 to 80% of transportation costs. DETAILED DESCRIPTION

[0029] In order to make the present invention more easily understood, the present invention will be described in detail below in conjunction with embodiments. These embodiments are only for illustration and are not intended to limit the application scope of the present invention.

[0030] A high-performance powdered alkali-free quick-setting agent core masterbatch. The raw materials of the invention include, by weight, 50-75 parts of a coagulant component, 5-15 parts of fluorosilicate, 10-20 parts of a fluorine-aluminum complex, 5-10 parts of an early strength component, 1-2 parts of a suspension component, 1-3 parts of a pH regulating component, and 0.5-1 part of an anti-caking component.

[0031] The percentages described in the present invention are all mass percentages unless otherwise specified. The raw materials described can be obtained from public commercial channels unless otherwise specified.

[0032] Example 1

[0033] 1) Weigh and prepare the raw materials according to the following mass percentages: 55 parts of accelerating coagulant component, 15 parts of fluorosilicate, 16 parts of fluoroaluminum complex, 10 parts of early strength component, 1.5 parts of suspension component, 2 parts of pH adjusting component, and 0.5 parts of anti-caking component;

[0034] 2) Example 1 The preparation method of the high-performance powdered alkali-free quick-setting agent core masterbatch comprises the following steps:

[0035] (1) Place a certain amount of accelerating coagulant component into a dryer and dry at 95°C for 4 hours. Take out the dried sample and grind it into powder with a fineness of 100-200 mesh and a moisture content of less than 5%. Accurately weigh 55 portions of the stabilizer for later use.

[0036] (2) Fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 80°C for 2 hours, cooled to room temperature, and a total of 45 portions are accurately weighed for use.

[0037] (3) The standby stabilizers obtained in the above steps (1) and (2) are fully mixed in a ratio of 55:45 to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch KWT-1.

[0038] Example 2

[0039] 1) Weigh and prepare the raw materials according to the following mass percentages: 60 parts of accelerating coagulant component, 13 parts of fluorosilicate, 15 parts of fluoroaluminum complex, 8 parts of early strength component, 1.5 parts of suspension component, 2 parts of pH adjusting component, and 0.5 parts of anti-caking component;

[0040] 2) Example 2 The preparation method of the high-performance powdered alkali-free quick-setting agent core masterbatch comprises the following steps:

[0041] (1) Place a certain amount of coagulant component in a dryer and dry at 95°C for 4 hours. Take out the dried sample and grind it in a grinder to obtain a powder with a fineness of 100-200 mesh and a moisture content of less than 5%. Accurately weigh 60 portions of the stabilizer for later use.

[0042] (2) Fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 80°C for 2 hours, cooled to room temperature, and a total of 40 portions are accurately weighed for use.

[0043] (3) The standby stabilizers obtained in the above steps (1) and (2) are fully mixed in a ratio of 60:40 to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch KWT-2.

[0044] Example 3

[0045] 1) Weigh and prepare the raw materials according to the following mass percentages: 65 parts of accelerating coagulant component, 10 parts of fluorosilicate, 17.5 parts of fluoroaluminum complex, 5 parts of early strength component, 1 part of suspension component, 1 part of pH adjusting component, and 0.5 part of anti-caking component;

[0046] 2) Example 3 The preparation method of the high-performance powdered alkali-free quick-setting agent core masterbatch comprises the following steps:

[0047] (1) Place a certain amount of coagulant component in a dryer and dry at 95°C for 4 hours. Take out the dried sample and grind it in a grinder to obtain a powder with a fineness of 100-200 mesh and a moisture content of less than 5%. Accurately weigh 65 portions of the stabilizer for later use.

[0048] (2) Fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 80°C for 2 hours, cooled to room temperature, and a total of 35 portions are accurately weighed for use.

[0049] (3) The standby stabilizers obtained in the above steps (1) and (2) are fully mixed in a ratio of 65:35 to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch KWT-3.

[0050] Example 4

[0051] 1) Weigh and prepare the raw materials according to the following mass percentages: 70 parts of accelerating coagulant component, 7.5 parts of fluorosilicate, 15 parts of fluoroaluminum complex, 5 parts of early strength component, 1 part of suspension component, 1 part of pH adjusting component, and 0.5 part of anti-caking component;

[0052] 2) Example 4 The preparation method of the high-performance powdered alkali-free quick-setting agent core masterbatch comprises the following steps:

[0053] (1) Place a certain amount of coagulant component in a dryer and dry at 95°C for 4 hours. Take out the dried sample and grind it in a grinder to obtain a powder with a fineness of 100-200 mesh and a moisture content of less than 5%. Accurately weigh 70 parts of the stabilizer for later use.

[0054] (2) Fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 80°C for 2 hours, cooled to room temperature, and a total of 30 portions are accurately weighed for use.

[0055] (3) The standby stabilizers obtained in the above steps (1) and (2) are fully mixed in a ratio of 70:30 to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch KWT-4.

[0056] Example 5

[0057] 1) Weigh and prepare the raw materials according to the following mass percentages: 75 parts of accelerating coagulant component, 5 parts of fluorosilicate, 15 parts of fluoroaluminum complex, 3.5 parts of early strength component, 0.5 parts of suspension component, 0.5 parts of pH adjusting component, and 0.5 parts of anti-caking component;

[0058] 2) Example 5 The preparation method of the high-performance powdered alkali-free quick-setting agent core masterbatch comprises the following steps:

[0059] (1) Place a certain amount of coagulant component in a dryer and dry at 95°C for 4 hours. Take out the dried sample and grind it in a grinder to obtain a powder with a fineness of 100-200 mesh and a moisture content of less than 5%. Accurately weigh 75 portions of the stabilizer for later use.

[0060] (2) Fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 80°C for 2 hours, cooled to room temperature, and a total of 25 portions are accurately weighed for use.

[0061] (3) The standby stabilizers obtained in the above steps 1 and 2 are fully mixed in a ratio of 75:25 to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch KWT-5.

[0062] Comparative Example 1

[0063] The powdered accelerating agent is selected from Shanxi Jiawei New Materials Co., Ltd., model 1801P.

[0064] Comparative Example 2

[0065] Powdered alkali-free accelerating setting agent selected from Yunnan Fluorine Industry Environmental Protection Technology Co., Ltd.

[0066] Test Example 1 Performance Test

[0067] The high-performance powdered alkali-free quick-setting agent core masterbatch KWT-1-KWT-5 prepared in Examples 1-5 was mixed with water at a ratio of 50:50 and dissolved thoroughly. Comparative Examples 1 and 2 were mixed with water at a ratio of 50:50 and dissolved thoroughly.

[0068] The high-performance powdered alkali-free quick-setting agent core masterbatch KWT-1-KWT-5 prepared in Examples 1-5 were mixed with industrial aluminum sulfate and water in a ratio of 30:30:40 and dissolved thoroughly. Comparative Examples 1 and 2 were mixed with industrial aluminum sulfate and water in a ratio of 30:30:40 and dissolved thoroughly.

[0069] The conventional alkali-free liquid accelerating agent prepared by the above two ratios was added to the cement paste or cement mortar sample at 6-9% of the mass of cement (Yilan Hongshi Cement), and the setting time and compressive strength were tested according to the standard of GB / T35159-2017 "Accelerating Agent for Shotcrete". The relevant performance test results are shown in Table 1.

[0070] Table 1 Related performance test results

[0071]

[0072] Table 1 shows that the high-performance powdered alkali-free accelerator core masterbatch of the present invention, after being compounded with water or aluminum sulfate into a conventional alkali-free liquid accelerator, all indicators meet the requirements of GB / T35159-2017 "Accelerator for Shotcrete" standard.

[0073] Test Example 2 Performance Test

[0074] According to the results in Test Example 1, Example 4 with the best comprehensive performance was used to test the performance of high-performance powdered alkali-free accelerator core masterbatch KWT-4 after being thoroughly mixed and dissolved with industrial aluminum sulfate and water in the ratios of 15:45:40, 20:40:40, 25:35:40, and 30:30:40. The high-performance powdered alkali-free accelerator core masterbatch KWT-4 prepared in Example 4 was selected and thoroughly mixed and dissolved with water and mother liquor (prepared by the enterprise) in the ratios of 10:20:70, 15:25:60, 20:30:50, and 30:35:35.

[0075] The conventional alkali-free liquid accelerating agent prepared in the above proportion was added to the cement paste or cement mortar sample at 6-9% of the mass of cement (Yilan Hongshi Cement), and the setting time and compressive strength were tested in accordance with the standard of GB / T35159-2017 "Accelerating Agent for Shotcrete". The relevant performance test results are shown in Table 2.

[0076] Table 2 Related performance test results

[0077]

[0078] The relevant test results are shown in Table 2, indicating that the high-performance powdered alkali-free quick-setting agent core masterbatch of the present invention, after being compounded with water, aluminum sulfate or mother liquor into a conventional alkali-free liquid quick-setting agent, all indicators meet the requirements of the standard GB / T35159-2017 "Accelerator for Shotcrete". It is verified again that the high-performance powdered alkali-free quick-setting agent core masterbatch can be compounded with water into liquid products with different solid contents according to the adaptability of different cements at the site of use, and can also be compounded to introduce multiple components such as aluminum sulfate and mother liquor, which not only improves the product performance, but also reduces the cost of compounding to a certain extent, realizes product diversification, not only reduces the packaging and transportation costs, but also adds more adjustment options for on-site compounding.

[0079] Test Example 3 Cement Adaptability Test

[0080] According to the results of Test Examples 1 and 2, Example 4 with the best comprehensive performance (core masterbatch: aluminum sulfate: water = 30:30:40) was used with a dosage of 6% to test its adaptability to cement from various manufacturers. The results are shown in Table 3.

[0081] Table 3 Cement adaptability test results

[0082]

[0083] The cement adaptability test results are shown in Table 3, indicating that the high-performance powdered alkali-free quick-setting agent core masterbatch of the invention can still meet the construction requirements of shotcrete with different brands of cement at a lower dosage, and shows strong adaptability to engineering cement.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance powdered alkali-free accelerating agent core masterbatch, characterized in that: The raw materials include, by weight: 50-75 parts of accelerating coagulant component, 5-15 parts of fluorosilicate, 10-20 parts of fluoroaluminum complex, 5-10 parts of early strength component, 1-2 parts of suspension component, 1-3 parts of pH adjusting component and 0.5-1 part of anti-caking component.

2. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The coagulant accelerating component is at least one of industrial grade aluminum sulfate 18hydrate and polyaluminum sulfate, which is self-made by the enterprise and has a water content of less than 5%.

3. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The fluorosilicate is at least one of magnesium fluorosilicate, zinc fluorosilicate, sodium fluorosilicate and potassium fluorosilicate.

4. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The fluoroaluminum complex is a stable mixture of high aluminum and high fluorine with good water solubility, which is self-made by the enterprise.

5. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The early strength component is at least one of lithium sulfate, zirconium sulfate, magnesium sulfate, sodium sulfate and solid alcohol amine.

6. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The suspended component is at least one of sepiolite, magnesium aluminum silicate, bentonite, attapulgite or magnesium aluminum hydrotalcite.

7. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The pH adjusting component is at least one of anhydrous sodium hydroxide, anhydrous calcium hydroxide and anhydrous calcium carbonate.

8. The high-performance powdered alkali-free accelerating agent core masterbatch according to claim 1, characterized in that: The anti-caking component is at least one of microcrystalline cellulose, talcum powder and sodium hydroxymethyl cellulose.

9. The method for preparing a high-performance powdery alkali-free accelerating agent core masterbatch according to any one of claims 1 to 8, characterized in that: The steps include: 1) Put a certain amount of accelerating coagulant component into a dryer, dry at 90-105°C for 3-5h, take it out and grind it in a grinder to obtain a powder with a moisture content of less than 5% and a fineness of 100-200 mesh; 2) The fluorosilicate, fluoroaluminum complex, early strength component, suspension component, pH adjustment component and anti-caking component are mixed uniformly according to the proportion, placed in a drying machine at 70-90°C for 1-2 hours, and cooled to room temperature for use; 3) The stabilizers obtained in the above steps 1) and 2) are mixed uniformly according to the proportion to obtain a high-performance powdered alkali-free quick-setting agent core masterbatch.

10. The use of a high-performance powdered alkali-free accelerating agent core masterbatch according to any one of claims 1 to 9, characterized in that: Applied to shotcrete, it complies with the dosage requirements of national standard GB / T35159-2017 "Alkali-free Accelerator for Shotcrete", and the dosage range is 6-9% of cement mass.

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