Calcium hydroxide with high condensation resistance and preparation method thereof

Abstract

The invention discloses calcium hydroxide with high condensation resistance and a preparation method thereof, and belongs to the technical field of calcium hydroxide preparation. The composite material is prepared from the following raw materials in parts by weight: 65-85 parts of calcium hydroxide, 10-20 parts of an inert material precursor, 0.5-4.5 parts of fatty acid, 5-15 parts of an inorganic inert material and 0.4-1 part of a reaction inhibitor. Silicon dioxide is deposited on the surface of calcium hydroxide through a coprecipitation method, a uniform compound is formed, then fatty acid reacts with calcium hydroxide, hydrophobic calcium salt is generated, and the surfaces of calcium hydroxide particles are coated with the hydrophobic calcium salt. Through the synergistic effect of the two, the hydrophobic performance of the calcium hydroxide particles is improved. Chemical hardening of calcium hydroxide is inhibited by a reaction inhibitor. The anti-condensation performance of the calcium hydroxide is improved in physical and chemical aspects, and the anti-condensation performance of the calcium hydroxide is improved while the activity of the calcium hydroxide is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of calcium hydroxide preparation, and particularly relates to calcium hydroxide with high anti-coagulation performance and a preparation method thereof. Background Art

[0002] As an important inorganic chemical product, calcium hydroxide is widely used in environmental protection, building materials, chemical industry and other fields. However, calcium hydroxide easily absorbs moisture in the air, forming a water film on the surface of the particles, resulting in physical agglomeration. When calcium hydroxide is exposed to the air, it easily reacts with carbon dioxide to form calcium carbonate, causing it to harden. The hygroscopic agglomeration problem of traditional calcium hydroxide will lead to a decrease in its flowability during storage and transportation, a decrease in activity and efficiency during use, and an increase in production energy consumption and costs.

[0003] Invention patent CN108911535B discloses a preparation process of high-activity anti-coagulation calcium hydroxide, in which high-activity anti-coagulation calcium hydroxide powder is prepared through high-temperature calcination, crushing and screening, digestion reaction, filtration, dehydration, drying, screening and filtration, etc. However, this process simply controls the particle size through mechanical screening, which belongs to the physical modification treatment of calcium hydroxide, and does not greatly improve the anti-coagulation performance of calcium hydroxide. The produced high-activity anti-coagulation calcium hydroxide powder easily absorbs moisture and carbon dioxide in the air, and is extremely easy to absorb moisture and agglomerate.

[0004] Since the anti-coagulation performance of calcium hydroxide powder manufactured by physical modification alone is poor, the problem of calcium hydroxide's easy moisture absorption and agglomeration is currently mainly solved by chemical surface treatment, and the hydrophobic properties of the surface of calcium hydroxide particles are improved by methods such as fatty acid hydrophobic agents, silane coupling agent modification, and organic polymer coating. Summary of the invention

[0005] In order to solve the problem that the calcium hydroxide powder manufactured by the prior art is easy to absorb moisture and agglomerate, and the anti-coagulation performance and activity cannot be taken into account at the same time, the present invention provides a calcium hydroxide with high anti-coagulation performance and a preparation method thereof. The calcium hydroxide with high anti-coagulation performance provided by the present invention has high activity while ensuring hydrophobicity.

[0006] The specific technical scheme of the present invention is:

[0007] A calcium hydroxide with high anti-coagulation performance is prepared from the following raw materials in parts by weight: 65-85 parts of calcium hydroxide, 10-20 parts of an inert material precursor, 0.5-4.5 parts of a fatty acid, 5-15 parts of an inorganic inert material, and 0.4-1 part of a reaction inhibitor.

[0008] Calcium hydroxide with high anti-caking performance of the present invention uniformly distributes silica on the surface of calcium hydroxide particles through a co-precipitation reaction with tetraethyl orthosilicate, forming a hierarchical pore structure, improving mass transfer efficiency and slowing down carbonization. Then, calcium stearate generated by the reaction of stearic acid and calcium hydroxide coats the calcium hydroxide particles, enabling silica to stay more stably on the surface of calcium hydroxide particles. At the same time, due to the excellent hydrophobic properties of calcium stearate, the hydrophobic properties of calcium hydroxide particles are also improved. The reaction inhibitor can preferably inhibit the reaction of calcium hydroxide particles with carbon dioxide in the air, inhibit the chemical hardening of calcium hydroxide, and prevent the deterioration of calcium hydroxide. Finally, by adding inorganic inert materials, the fluidity of calcium hydroxide powder is improved.

[0009] Preferably, the inert material precursor is one or more of sodium silicate, tetraethyl orthosilicate, sodium aluminate, and aluminum nitrate. More preferably, the inert material precursor is tetraethyl orthosilicate.

[0010] In the process of using the co-precipitation method to prepare a uniform composite, by adding tetraethyl orthosilicate to the calcium hydroxide suspension, the inert material precursor can deposit silica on the surface of calcium hydroxide through a hydrolysis reaction, forming a uniform composite and improving the hydrophobic properties of the surface of calcium hydroxide particles.

[0011] Preferably, the fatty acid is one or more of stearic acid, oleic acid, and palmitic acid. More preferably, the fatty acid is stearic acid.

[0012] Stearic acid reacts with calcium hydroxide to generate a hydrophobic calcium salt, which coats the surface of calcium hydroxide particles and improves the hydrophobic properties of calcium hydroxide particles.

[0013] Preferably, the inorganic inert material is one or more of carbonate, mica, graphite, and carbon black. More preferably, the inorganic inert material is mica.

[0014] The fluidity of calcium hydroxide powder is improved by mica, making the powder not easily absorb moisture and cake.

[0015] Preferably, the reaction inhibitor is one or more of oxalic acid, citric acid, and tartaric acid. More preferably, the reaction inhibitor is citric acid.

[0016] Citric acid inhibits the reaction of calcium hydroxide with carbon dioxide in the air to produce calcium carbonate, inhibiting the chemical hardening process of calcium hydroxide.

[0017] A preparation method of calcium hydroxide with high anti-caking performance is as follows: 1) Obtain calcium hydroxide coarse powder after subjecting quicklime lumps to high-temperature calcination, crushing and screening, digestion, filtration, dehydration, and drying treatments; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension, then add the inert material precursor. After aging, washing, and drying, a composite material of calcium hydroxide and silicon dioxide is obtained; 3) Add fatty acid to the composite material and stir at high speed to obtain a modified composite material of calcium hydroxide and silicon dioxide 4) Add inorganic inert material and reaction inhibitor to the composite material, grind it into a powder and mix evenly to obtain calcium hydroxide with high anti-coagulation performance.

[0018] Beneficial effects:

[0019] For the calcium hydroxide with high anti-coagulation performance of the present invention, silicon dioxide is evenly distributed on the surface of calcium hydroxide particles by the co-precipitation method, and then the hydrophobic calcium salt generated by the reaction of fatty acid and calcium hydroxide coats the calcium hydroxide particles. The two methods work synergistically to not only ensure the stable adsorption of silicon dioxide on the surface of calcium hydroxide particles, but also greatly improve the hydrophobic performance of calcium hydroxide particles. At the same time, due to the low dosage of fatty acid and the presence of silicon dioxide on the surface of calcium hydroxide particles, the generated hydrophobic calcium salt cannot completely coat the calcium hydroxide particles, thus ensuring the activity of calcium hydroxide particles. Specific embodiments

[0020] To better illustrate the technical effects of the present invention, the following specific examples and comparative examples are analyzed.

[0021] General example:

[0022] A kind of calcium hydroxide with high anti-coagulation performance is prepared from the following raw materials in parts by weight: 65 - 85 parts of calcium hydroxide, 10 - 20 parts of inert material precursor, 0.5 - 4.5 parts of fatty acid, 5 - 15 parts of inorganic inert material, 0.4 - 1 part of reaction inhibitor.

[0023] A preparation method of a kind of calcium hydroxide with high anti-coagulation performance is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing, and screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After successive reactions in the three-stage digester, a crude calcium hydroxide slurry is obtained. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge. Finally, dry it at 150 - 300 °C to obtain crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension, then add tetraethyl orthosilicate, age at 25 - 80 °C for 1 - 24 h, then wash with deionized water, and dry at 80 - 100 °C under normal pressure to obtain a composite material of calcium hydroxide and silicon dioxide; 3) Add stearic acid to the composite material, and stir at a speed of 800 r / min at 60-80 °C to obtain a composite material of modified calcium hydroxide and silica; 4) Add mica flakes and citric acid to the composite material, grind it into a powder and mix well to obtain calcium hydroxide with high anti-caking performance.

[0024] Example 1

[0025] A kind of calcium hydroxide with high anti-caking performance is prepared from the following raw materials in parts by weight: 75 parts of calcium hydroxide, 15 parts of tetraethyl orthosilicate, 2.5 parts of stearic acid, 10 parts of mica flakes, and 0.7 part of citric acid.

[0026] A preparation method of a kind of calcium hydroxide with high anti-caking performance is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900-1200 °C for 8-12 h. Add the calcined product to a crusher for crushing, and screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1-1.3 times that of calcium oxide to the digester for digestion reaction. After reacting step by step through the three-stage digester, a crude calcium hydroxide slurry is obtained. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge, and finally dry it at 150-300 °C to obtain crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension, then add tetraethyl orthosilicate, age at 25-80 °C for 1-24 h, then wash with deionized water, and dry at 80-100 °C under normal pressure to obtain a composite material of calcium hydroxide and silica; 3) Add stearic acid to the composite material, and stir at a speed of 800 r / min at 60-80 °C to obtain a composite material of modified calcium hydroxide and silica; 4) Add mica flakes and citric acid to the composite material, grind it into a powder and mix well to obtain calcium hydroxide with high anti-caking performance.

[0027] Example 2

[0028] A kind of calcium hydroxide with high anti-caking performance is prepared from the following raw materials in parts by weight: 65 parts of calcium hydroxide, 10 parts of tetraethyl orthosilicate, 0.5 part of stearic acid, 5 parts of mica flakes, and 0.4 part of citric acid.

[0029] A preparation method of a kind of calcium hydroxide with high anti-caking performance is as follows: 1) Put quicklime lumps into a rotary kiln and calcine them at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing. Screen calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After step-by-step reaction in the three-stage digester, obtain crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it with a centrifuge. Finally, dry it at 150 - 300 °C to obtain crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension. Then add tetraethyl orthosilicate and age it at 25 - 80 °C for 1 - 24 h. Then wash it with deionized water and dry it under normal pressure at 80 - 100 °C to obtain a composite material of calcium hydroxide and silicon dioxide; 3) Add stearic acid to the composite material and stir it at a speed of 800 r / min at 60 - 80 °C to obtain a modified composite material of calcium hydroxide and silicon dioxide; 4) Add mica flakes and citric acid to the composite material, grind it into a powder and mix it evenly to obtain calcium hydroxide with high anti-caking performance.

[0030] Example 3

[0031] A kind of calcium hydroxide with high anti-caking performance is prepared from the following raw materials by weight: 85 parts of calcium hydroxide, 20 parts of tetraethyl orthosilicate, 4.5 parts of stearic acid, 15 parts of mica flakes, and 1 part of citric acid.

[0032] A preparation method of a kind of calcium hydroxide with high anti-caking performance is as follows: 1) Put quicklime lumps into a rotary kiln and calcine them at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing. Screen calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After step-by-step reaction in the three-stage digester, obtain crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it with a centrifuge. Finally, dry it at 150 - 300 °C to obtain crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension. Then add tetraethyl orthosilicate and age it at 25 - 80 °C for 1 - 24 h. Then wash it with deionized water and dry it under normal pressure at 80 - 100 °C to obtain a composite material of calcium hydroxide and silicon dioxide; 3) Add stearic acid to the composite material and stir it at a speed of 800 r / min at 60 - 80 °C to obtain a modified composite material of calcium hydroxide and silicon dioxide; 4) Add mica flakes and citric acid to the composite material, grind it into a powder and mix it evenly to obtain calcium hydroxide with high anti-caking performance.

[0033] Example 4

[0034] A calcium hydroxide with high anti-caking performance is prepared from the following raw materials in parts by weight: 75 parts of calcium hydroxide, 2.5 parts of stearic acid, 10 parts of mica flakes, and 0.7 part of citric acid.

[0035] A preparation method of a calcium hydroxide with high anti-caking performance is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher, screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of the calcium oxide to the digester for digestion reaction. After successive reactions in the three-stage digester, a crude calcium hydroxide slurry is obtained. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge. Finally, dry it at 150 - 300 °C to obtain crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension; 3) Add stearic acid to the calcium hydroxide suspension, stir at a speed of 800 r / min at 60 - 80 °C, and dry at 150 - 300 °C to obtain modified calcium hydroxide powder; 4) Add mica flakes and citric acid to the modified calcium hydroxide, grind it into a powder and mix well to obtain calcium hydroxide with high anti-caking performance.

[0036] Example 5

[0037] A calcium hydroxide with high anti-caking performance is prepared from the following raw materials in parts by weight: 75 parts of calcium hydroxide, 15 parts of tetraethyl orthosilicate, 10 parts of mica flakes, and 0.7 part of citric acid.

[0038] A preparation method of a calcium hydroxide with high anti-caking performance is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher, screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of the calcium oxide to the digester for digestion reaction. After successive reactions in the three-stage digester, a crude calcium hydroxide slurry is obtained. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge. Finally, dry it at 150 - 300 °C to obtain crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension, then add tetraethyl orthosilicate, age at 25 - 80 °C for 1 - 24 h, then wash with deionized water, and dry at 80 - 100 °C under normal pressure to obtain a composite material of calcium hydroxide and silicon dioxide; 3) Add mica flakes and citric acid to the composite material, grind it into powder and mix well to obtain calcium hydroxide with high anti-caking performance.

[0039] Example 6

[0040] A kind of calcium hydroxide with high anti-caking performance is prepared from the following raw materials in parts by weight: 75 parts of calcium hydroxide, 15 parts of tetraethyl orthosilicate, 2.5 parts of stearic acid, and 0.7 part of citric acid.

[0041] A preparation method of a kind of calcium hydroxide with high anti-caking performance is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing, and screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After step-by-step reaction in the three-stage digester, obtain the crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge, and finally dry it at 150 - 300 °C to obtain the crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension, then add tetraethyl orthosilicate, age at 25 - 80 °C for 1 - 24 h, then wash with deionized water, and dry at 80 - 100 °C under normal pressure to obtain a composite material of calcium hydroxide and silicon dioxide; 3) Add stearic acid to the composite material, stir at a speed of 800 r / min at 60 - 80 °C to obtain a modified composite material of calcium hydroxide and silicon dioxide; 4) Add citric acid to the composite material, grind it into powder and mix well to obtain calcium hydroxide with high anti-caking performance.

[0042] Example 7

[0043] A kind of calcium hydroxide with high anti-caking performance is prepared from the following raw materials in parts by weight: 75 parts of calcium hydroxide, 15 parts of tetraethyl orthosilicate, 2.5 parts of stearic acid, and 10 parts of mica flakes.

[0044] A preparation method of a kind of calcium hydroxide with high anti-caking performance is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing, and screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After step-by-step reaction in the three-stage digester, obtain the crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge, and finally dry it at 150 - 300 °C to obtain the crude calcium hydroxide powder; 2) Add water to the crude calcium hydroxide powder to make a calcium hydroxide suspension, then add tetraethyl orthosilicate, age at 25 - 80 °C for 1 - 24 h, then wash with deionized water, and obtain the composite material of calcium hydroxide and silicon dioxide after drying at normal pressure at 80 - 100 °C; 3) Add stearic acid to the composite material, stir at a speed of 800 r / min at 60 - 80 °C to obtain the modified composite material of calcium hydroxide and silicon dioxide; 4) Add mica flakes to the composite material, grind it into powder and mix evenly to obtain calcium hydroxide with high anti - coagulation performance.

[0045] Comparative Example 1

[0046] This comparative example is calcium hydroxide powder manufactured by a conventional process. The specific process is as follows:

[0047] Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing, screen the calcium oxide stones with a particle size less than 10 mm and place them in a three - stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After sequential reactions in the three - stage digester, obtain the crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge. Finally, dry it at 150 - 300 °C to obtain the crude calcium hydroxide powder.

[0048] Comparative Example 2

[0049] In this comparative example, the inert material precursor is replaced with silicon dioxide powder. The specific components are as follows:

[0050] 75 parts of calcium hydroxide, 20 parts of silicon dioxide powder, 2.5 parts of stearic acid, 10 parts of mica flakes, 0.7 part of citric acid.

[0051] The preparation method is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher for crushing, screen the calcium oxide stones with a particle size less than 10 mm and place them in a three - stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After sequential reactions in the three - stage digester, obtain the crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge. Finally, dry it at 150 - 300 °C to obtain the crude calcium hydroxide powder; 2) Add silicon dioxide powder to the crude calcium hydroxide powder, grind and mix evenly, then add water to make a mixture of calcium hydroxide and silicon dioxide; 3) Add stearic acid to the mixture, stir at a speed of 800 r / min at 60 - 80 °C, and dry at 150 - 300 °C to obtain the modified calcium hydroxide powder; 4) Add mica flakes and citric acid to the modified calcium hydroxide, grind them into powder and mix well to obtain calcium hydroxide with high anti-caking performance.

[0052] Comparative Example 3

[0053] This comparative example is calcium hydroxide powder modified with silane coupling agent. The specific process is as follows: 1) Put the quicklime lumps into a rotary kiln and calcine them at a temperature of 900 - 1200 °C for 8 - 12 h. Add the calcined product to a crusher, screen the calcium oxide stones with a particle size less than 10 mm and place them in a three-stage digester. Add pure water with a mass 1.1 - 1.3 times that of calcium oxide to the digester for digestion reaction. After step-by-step reaction in the three-stage digester, obtain crude calcium hydroxide slurry. Filter the obtained crude calcium hydroxide slurry through a sieve plate and then dehydrate it by a centrifuge. Finally, dry it at 150 - 300 °C to obtain crude calcium hydroxide powder; 2) Preheat the calcium hydroxide powder to 80 - 100 °C, spray in the silane coupling agent, and mix it at a high speed of 1000 - 1500 r / min for 20 - 30 min to obtain modified calcium hydroxide powder.

[0054] Perform performance tests on Examples 1 - 7 and Comparative Examples 1 - 3:

[0055] Hygroscopicity test:

[0056] Weigh 10 g of the calcium hydroxide sample, place it in a constant humidity box with a humidity of 80% and a temperature of 25 °C for 24 h, then take it out and weigh it to calculate the hygroscopicity rate.

[0057] Caking strength test:

[0058] Take 100 g of the sample, store it in a sealed container at 40 °C and a humidity of 75% for 7 days. Take out the lumpy calcium hydroxide and measure the pressure required to break the lumps to calculate the caking strength.

[0059] Carbonation rate determination:

[0060] Take 10 g of calcium hydroxide powder, process it in a sealed container at 40 °C and a carbon dioxide concentration of 10% for 72 h. Take the processed calcium hydroxide powder and titrate it with an excessive amount of 1 mol / L dilute hydrochloric acid, then add phenolphthalein indicator and back-titrate it with sodium hydroxide solution. Calculate the carbonation rate according to the amounts of the consumed dilute hydrochloric acid and sodium hydroxide solution.

[0061] Flowability (angle of repose) determination:

[0062] Evaluate the flowability by the powder stacking angle (θ).

[0063] The test results are shown in Table 1: Hygroscopicity (%) Caking strength (kPa) Carbonation rate (%) Angle of repose (θ) Example 1 1.5 2.9 5.1 23° Example 2 1.7 3.3 5.7 28° Example 3 1.6 3.0 5.5 24° Example 4 3.4 5.9 8.3 22° Example 5 3.1 5.7 7.8 24° Example 6 1.6 3.1 5.2 34° Example 7 1.6 3.2 10.3 23° Comparative Example 1 4.1 7.2 21.3 38.2° Comparative Example 2 2.8 4.7 7.7 25° Comparative Example 3 1.7 3.4 6.3 26°

[0064] In the carbonation rate test, a rapid evaluation scheme is used. The sample is treated in a sealed container at 40 °C with a carbon dioxide concentration of 10% for 72 h. At this time, the 72-hour treatment time is equivalent to a natural exposure time of 3 months.

[0065] Comparing the data of Comparative Examples 1-4, it can be seen that tetraethyl orthosilicate has a great influence on the hygroscopicity, caking strength, carbonation rate and other properties of calcium hydroxide powder. This is because tetraethyl orthosilicate deposits silica on the surface of calcium hydroxide particles through hydrolysis reaction, forming a uniform composite, which improves the hydrophobic property of the surface of calcium hydroxide particles. Since Comparative Example 4 does not contain tetraethyl orthosilicate, the hydrophobic property of this group of calcium hydroxide powder is poor, resulting in a higher subsequent carbonation rate.

[0066] Comparing the data of Comparative Example 1 and Example 5, it can be seen that stearic acid has a great influence on the hygroscopicity, caking strength, carbonation rate and other properties of calcium hydroxide powder. This is because stearic acid reacts with calcium hydroxide to produce stearate to coat calcium hydroxide particles, preventing the contact of calcium hydroxide particles with water and carbon dioxide in the air. Since Example 5 does not contain stearic acid, the properties of this group of calcium hydroxide except the angle of repose are not as good as those of Comparative Example 1.

[0067] Comparing the data of Comparative Example 1 and Example 6, it can be seen that mica flakes have a great influence on the fluidity of calcium hydroxide.

[0068] Comparing the data of Comparative Example 1 and Example 7, it can be seen that citric acid has a great influence on the carbonation rate of calcium hydroxide. This is because reaction inhibitors such as citric acid can inhibit the chemical hardening process of calcium hydroxide, that is, to a certain extent, prevent the reaction of calcium hydroxide with carbon dioxide in the air. Therefore, the carbonation rate of calcium hydroxide in Example 7 without adding citric acid is higher.

[0069] Comparing the data of the Comparative Example and Comparative Example 1, it can be seen that the properties of the calcium hydroxide of the present invention are superior to those of ordinary calcium hydroxide in all aspects. This is because calcium hydroxide with a single component has strong hydrophilicity and high surface energy, and is extremely easy to absorb moisture and cake when exposed to the air, and is also extremely easy to react with carbon dioxide in the air. Therefore, it is necessary to treat calcium hydroxide to improve its hydrophobic property while ensuring its reaction activity.

[0070] Comparing the data of Comparative Example 1 and Comparative Example 2, it can be seen that in Comparative Example 2, silica is fixed on the surface of calcium hydroxide particles by dry mixing, but this process belongs to a simple physical mixing method. After this method is treated, the interfacial bonding between silica and calcium hydroxide particles is weak, and the improvement of the hydrophobic property of calcium hydroxide particles is unstable, and various properties change greatly with time.

[0071] Comparing the data of Comparative Example 1 and Comparative Example 3, it can be seen that the silane coupling agent can improve the hydrophobic property of calcium hydroxide to a certain extent. However, there are problems such as uneven modification and poor storage stability during the use of the silane coupling agent.

[0072] The raw materials and equipment used in the present invention are all common raw materials and equipment in the art without special instructions; the methods used in the present invention are all conventional methods in the art without special instructions.

[0073] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent transformations made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A calcium hydroxide with high anti - coagulation performance, characterized in that, Prepared from the following raw materials by weight: 65 - 85 parts of calcium hydroxide, 10 - 20 parts of inert material precursor, 0.5 - 4.5 parts of fatty acid, 5 - 15 parts of inorganic inert material, 0.4 - 1 part of reaction inhibitor.

2. The calcium hydroxide having high anti-coagulation performance according to claim 1, wherein The inert material precursor is one or more of sodium silicate, tetraethyl orthosilicate, sodium aluminate, and aluminum nitrate.

3. The calcium hydroxide with high anti-coagulation performance according to claim 1, characterized in that, The fatty acid is one or more of stearic acid, oleic acid, and palmitic acid.

4. The calcium hydroxide with high anti - condensation performance according to claim 1, characterized in that, The inorganic inert material is one or more of carbonate, mica, graphite, and carbon black.

5. The calcium hydroxide having high anti-coagulation performance according to claim 1, characterized in that, The reaction inhibitor is one or more of oxalic acid, citric acid, and tartaric acid.

6. A preparation method of calcium hydroxide with high anti-coagulation performance according to any one of claims 1-5, characterized in that, Including the following steps: 1) Obtain calcium hydroxide powder after subjecting quicklime lumps to surface treatment, calcination, crushing and screening, digestion reaction, filtration and dehydration treatment, and drying treatment. 2) Add water to the calcium hydroxide powder to form a calcium hydroxide suspension, then add the inert material precursor, and obtain a composite material of calcium hydroxide and silicon dioxide after aging, washing, and drying. 3) Add fatty acid to the composite material and obtain a modified composite material of calcium hydroxide and silicon dioxide after high-speed stirring. 4) Add inorganic inert material and reaction inhibitor to the composite material, grind it into a powder and mix evenly to obtain calcium hydroxide with high anti-coagulation performance.

7. The preparation method of calcium hydroxide with high anti - condensation performance according to claim 6, characterized in that, In step 1), add pure water with a mass 1.1 - 1.3 times that of calcium hydroxide during the digestion treatment.

8. The preparation method of calcium hydroxide with high anti - condensation performance according to claim 6, characterized in that, During the aging treatment, control the temperature at 25 - 80 °C and the time at 1 - 24 h.

9. The preparation method of calcium hydroxide with high anti - condensation performance according to claim 6, characterized in that, The drying treatment is atmospheric drying at 80 - 100 °C.

10. The preparation method of calcium hydroxide with high anti - coagulation performance according to any one of claims 6 - 9, characterized in that, In step 3), the reaction temperature of the composite material and the fatty acid is 60 - 80 °C.