Anti-blocking agent for potassium chloride particles as well as preparation method and application of anti-blocking agent

Abstract

The invention relates to an anti-blocking agent for potassium chloride particles as well as a preparation method and application of the anti-blocking agent. The anti-blocking agent comprises organic modified montmorillonite and hydrophobic white carbon black, the organic modified montmorillonite is prepared by modifying montmorillonite with a composite coupling agent composed of bis-(3-(triethoxysilane) propyl)-tetrasulfide, isopropyl triisostearoyl titanate and heptadecafluorodecyl trimethoxysilane, and due to the modification, the hydrophobicity of the montmorillonite can be remarkably improved, and the interlayer spacing of the montmorillonite can be optimized; therefore, the hydrophobic property of the anti-blocking agent is improved, and the anti-blocking effect is enhanced. The organic modified montmorillonite and hydrophobic white carbon black are simultaneously used in the anti-blocking agent, a hydrophobic film can be formed on the surface of potassium chloride particles by the anti-blocking agent, the hygroscopicity of the potassium chloride particles is synergistically reduced, the chemical stability of the potassium chloride particles is improved, good dispersity is kept in the storage and transportation process, and blocking is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of anti-caking agents, and in particular to an anti-caking agent for potassium chloride particles and a preparation method and application thereof. Background Art

[0002] The caking problem of water-soluble potassium chloride granular fertilizer is mainly affected by the moisture absorption of raw materials, water content, stacking pressure, humidity of production environment and water absorption of packaging materials. When fertilizer granules absorb moisture, their surface will dissolve and evaporate, and then form crystal bridges during the recrystallization process, causing the fertilizer granules to adhere to each other and gradually aggregate into large lumps.

[0003] In actual use, the caking of fertilizers will destroy their normal fluidity, and they need to be broken before use, which not only causes waste of resources and environmental pollution, but also increases the cost of use. In order to deal with this problem, a variety of anti-caking technologies have been adopted, including optimizing product packaging, improving production equipment processes, adjusting fertilizer dosage forms, changing fertilizer ingredients, improving storage conditions, and adding anti-caking agents. Among them, adding anti-caking agents is considered to be a simple and effective method.

[0004] At present, the anti-caking agents commonly used in powdered water-soluble fertilizers mainly include inorganic inert materials, surfactants and high molecular polymers. Among them, inorganic inert materials, such as talc, silicon dioxide and anhydrous magnesium sulfate, mainly prevent caking through mechanical isolation, but may affect the water solubility of the fertilizer, and the effect is limited in high humidity environments. Surfactants, such as sodium dodecylbenzene sulfonate, mainly use their water solubility to reduce the adsorption force between particles, thereby achieving the purpose of anti-caking, but the effect is limited when used alone, and the effect is not good in some high humidity environments. High molecular polymers, such as polyacrylamide, although the effect is significant, but the cost is high, and the environmental performance needs to be improved. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an anti-caking agent for potassium chloride granules and a preparation method and application thereof, which can effectively solve the agglomeration problem of potassium chloride granules during long-term storage.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides an anti-caking agent for potassium chloride particles, comprising the following components in parts by weight: 50-60 parts of organically modified montmorillonite and 20-30 parts of hydrophobic white carbon black; wherein the organically modified montmorillonite comprises the following raw materials: montmorillonite, a composite coupling agent and an initiator, the mass ratio of the montmorillonite, the composite coupling agent and the initiator is (1-1.5):1:(0.02-0.06), the composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane in a mass ratio of (1-1.5):1:(0.5-0.6); the particle size of the hydrophobic white carbon black is less than the particle size of the organically modified montmorillonite.

[0008] The anti-caking agent of the present invention comprises organic modified montmorillonite and hydrophobic white carbon black, wherein the organic modified montmorillonite is prepared by modifying the montmorillonite with a composite coupling agent composed of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane, wherein the bis-(3-(triethoxysilane)propyl)-tetrasulfide contains triethoxysilyl (-Si(OEt) 3 ) and tetrasulfide bonds (-S 4 -), the triethoxysilane group can react with the hydroxyl groups on the surface of montmorillonite to form a condensation reaction, thereby grafting the hydrophobic tetrasulfide bond to the surface of montmorillonite, thereby improving the hydrophobic properties of montmorillonite; triisostearyl titanate isopropyl contains a hydrophobic stearoyl group, which can significantly enhance the hydrophobic properties of montmorillonite; the heptadecafluorodecyl trimethoxysilane molecule contains a long-chain perfluoroalkyl group (-CF 3 (CF 2 ) 7 CH 2 CH 2 -), this group has extremely low surface energy and can significantly reduce the hydrophilicity of the montmorillonite surface. The three coupling agents work synergistically and can enter the interlayer of montmorillonite through chemical bonding, effectively improving the hydrophobicity of montmorillonite and optimizing the interlayer distance of montmorillonite, so that a stable hydrophobic film is attached to the surface of montmorillonite. When the anti-caking agent is compounded with potassium chloride particles, this hydrophobic film not only reduces the hygroscopicity of potassium chloride particles, but also improves the chemical stability of potassium chloride particles, so that it maintains good stability during storage and transportation and avoids agglomeration.

[0009] In addition, since the particle size of the hydrophobic silica in the present invention is smaller than the particle size of the organic modified montmorillonite, the small particle size silica can be embedded in the layered structure of the montmorillonite, thereby further increasing the interlayer spacing of the montmorillonite, reducing the adsorption of water molecules, and synergistically improving the hydrophobic performance of the anti-caking agent.

[0010] Preferably, the initiator is dicumyl peroxide.

[0011] Preferably, the mesh size of the montmorillonite is 200-300 meshes.

[0012] Preferably, the mesh size of the hydrophobic white carbon black is 400-600 mesh.

[0013] Preferably, the composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, isopropyl triisostearoyl titanate and heptadecafluorodecyl trimethoxysilane in a mass ratio of 1.3:1:0.5.

[0014] In a second aspect, the present invention provides a method for preparing an anti-caking agent for potassium chloride particles in the first aspect, comprising the following steps:

[0015] S1, dispersing montmorillonite in anhydrous ethanol and stirring evenly, adding a composite coupling agent and an initiator to react, after the reaction is completed, filtering, washing to neutrality, and drying to obtain an organic modified montmorillonite;

[0016] S2. Ball-milling the organic modified montmorillonite and the hydrophobic white carbon black to obtain an anti-caking agent for the potassium chloride particles.

[0017] Preferably, the amount of anhydrous ethanol added is 1-2 times the total mass of montmorillonite, the composite coupling agent and the initiator.

[0018] Preferably, in step S1, the reaction temperature is 70-90° C. and the reaction time is 2-3 h.

[0019] Preferably, in step S1, the organically modified montmorillonite and the hydrophobic silica are ball-milled to a size of 600-700 mesh.

[0020] In a third aspect, the present invention provides use of the anti-caking agent for potassium chloride granules in the first aspect in the preparation of potassium chloride granular fertilizer.

[0021] Preferably, the anti-caking agent for the potassium chloride granules is added in an amount of 0.1-0.5 wt % in the potassium chloride granule fertilizer.

[0022] Specifically, the compounding method of the anti-caking agent and potassium chloride granular fertilizer includes the following steps: adding the anti-caking agent into a stirring device through a feeder, mixing it evenly with the potassium chloride granules, and then conveying and packaging it through a conveyor belt and a finished product scraper.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The anti-caking agent of the present invention includes organically modified montmorillonite and hydrophobic white carbon, wherein the organically modified montmorillonite is prepared by modifying montmorillonite with a composite coupling agent consisting of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearoyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane, and a hydrophobic group is introduced by chemical bonding, and the modification can significantly improve the hydrophobicity of montmorillonite and optimize the interlayer spacing of montmorillonite, thereby improving the hydrophobicity of the anti-caking agent and enhancing the anti-caking effect. The organically modified montmorillonite and hydrophobic white carbon are used in the anti-caking agent at the same time, and a hydrophobic film can be formed on the surface of potassium chloride particles in the anti-caking agent, and the hygroscopicity of potassium chloride particles is synergistically reduced, and its chemical stability is improved. When the anti-caking agent is compounded with potassium chloride particles, the anti-caking agent is attached with a hydrophobic film on the surface of potassium chloride, which can reduce the hygroscopicity of potassium chloride particles, improve its chemical stability, and ensure that good dispersibility is maintained during storage and transportation to prevent caking. DETAILED DESCRIPTION

[0025] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0026] The sources of the raw materials used in the following examples and comparative examples are as follows:

[0027] Montmorillonite: The manufacturer is Lingshou County Kaihaoming Mineral Products Processing Factory, model is k0005, mesh number is 200 mesh;

[0028] Bis-(3-(triethoxysilyl)propyl)-tetrasulfide: manufacturer is Evonik of Germany, model is Si-69;

[0029] Isopropyl triisostearyl titanate: manufacturer is Guangdong Wengjiang Chemical Technology Co., Ltd., model number is PC96666;

[0030] Heptadecafluorodecyltrimethoxysilane: manufacturer is Nanjing Quanxi New Material Technology Co., Ltd., model number is 1713;

[0031] Dicumyl peroxide: manufacturer is Jiangsu Daoming Chemical Co., Ltd., model number is DCP;

[0032] Hydrophobic white carbon black: the manufacturer is Tonghua Shuanglong Chemical Co., Ltd., the model is 1-3-5, the mesh number is 600 mesh, and the purity is 91%;

[0033] Potassium chloride: The manufacturer is Shandong Xinheng Chemical Co., Ltd.

[0034] Unless otherwise specified, other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0035] It should be noted that montmorillonite and hydrophobic silica need to be sieved to a specific mesh size before use.

[0036] Example 1

[0037] An anti-caking agent for potassium chloride particles comprises the following components in parts by weight: 52 parts of organically modified montmorillonite and 25 parts of hydrophobic white carbon black; wherein the organically modified montmorillonite comprises the following raw materials: montmorillonite, a composite coupling agent and an initiator, the mass ratio of the montmorillonite, the composite coupling agent and the initiator is 1.2:1:0.05, the composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearoyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane in a mass ratio of 1.3:1:0.5; and the initiator is diisopropylbenzene peroxide.

[0038] The method for preparing the anti-caking agent for potassium chloride particles comprises the following steps:

[0039] S1. Disperse montmorillonite in anhydrous ethanol and stir evenly, add a composite coupling agent and an initiator, react at 80°C for 2.5h, filter after the reaction is completed, wash to neutrality, and dry to obtain an organic modified montmorillonite; wherein the amount of anhydrous ethanol added is twice the total mass of the montmorillonite, the composite coupling agent and the initiator;

[0040] S2. Ball-milling the organic modified montmorillonite and the hydrophobic white carbon black to 650 meshes to obtain an anti-caking agent for the potassium chloride particles.

[0041] Example 2

[0042] An anti-caking agent for potassium chloride particles comprises the following components in parts by weight: 50 parts of organically modified montmorillonite and 20 parts of hydrophobic white carbon black; wherein the organically modified montmorillonite comprises the following raw materials: montmorillonite, a composite coupling agent and an initiator, the mass ratio of the montmorillonite, the composite coupling agent and the initiator is 1:1:0.02, the composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane in a mass ratio of 1:1:0.5; the mesh number of the montmorillonite is 200 meshes, and the mesh number of the hydrophobic white carbon black is 400 meshes; and the initiator is diisopropylbenzene peroxide.

[0043] The method for preparing the anti-caking agent for potassium chloride particles comprises the following steps:

[0044] S1. Disperse montmorillonite in anhydrous ethanol and stir evenly, add a composite coupling agent and an initiator, react at 70°C for 3h, filter after the reaction is completed, wash to neutrality, and dry to obtain an organic modified montmorillonite; wherein the amount of anhydrous ethanol added is 2 times the total mass of the montmorillonite, the composite coupling agent and the initiator;

[0045] S2. Ball-milling the organic modified montmorillonite and the hydrophobic white carbon black to 600 meshes to obtain an anti-caking agent for the potassium chloride particles.

[0046] Example 3

[0047] An anti-caking agent for potassium chloride particles comprises the following components in parts by weight: 60 parts of organically modified montmorillonite and 30 parts of hydrophobic white carbon black; wherein the organically modified montmorillonite comprises the following raw materials: montmorillonite, a composite coupling agent and an initiator, the mass ratio of the montmorillonite, the composite coupling agent and the initiator is 1.5:1:0.06, the composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearoyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane in a mass ratio of 1.5:1:0.6; the initiator is diisopropylbenzene peroxide.

[0048] The method for preparing the anti-caking agent for potassium chloride particles comprises the following steps:

[0049] S1. Disperse montmorillonite in anhydrous ethanol and stir evenly, add a composite coupling agent and an initiator, react at 90° C. for 2 h, filter after the reaction is completed, wash to neutrality, and dry to obtain an organic modified montmorillonite; wherein the amount of anhydrous ethanol added is 3 times the total mass of the montmorillonite, the composite coupling agent and the initiator;

[0050] S2. Ball-milling the organic modified montmorillonite and the hydrophobic white carbon black to 700 meshes to obtain an anti-caking agent for the potassium chloride particles.

[0051] Comparative Example 1

[0052] The difference between Comparative Example 1 and Example 1 is that the montmorillonite is not modified by the composite coupling agent, and an equal amount of montmorillonite is used to replace the organic modified montmorillonite.

[0053] Comparative Example 2

[0054] The difference between Comparative Example 2 and Example 1 is that the total mass of the composite coupling agent remains unchanged, bis-(3-(triethoxysilane)propyl)-tetrasulfide is not added, and triisostearyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane in a mass ratio of 1:0.5 are used to make up for the missing amount.

[0055] Comparative Example 3

[0056] The difference between Comparative Example 3 and Example 1 is that the total mass of the composite coupling agent remains unchanged, triisostearyl titanate isopropyl is not added, and bis-(3-(triethoxysilane)propyl)-tetrasulfide and heptadecafluorodecyltrimethoxysilane in a mass ratio of 1.3:0.5 are used to make up for the missing amount.

[0057] Comparative Example 4

[0058] The difference between Comparative Example 4 and Example 1 is that the total mass of the composite coupling agent remains unchanged, heptadecafluorodecyltrimethoxysilane is not added, and bis-(3-(triethoxysilane)propyl)-tetrasulfide and triisostearyl titanate isopropyl ester with a mass ratio of 1.3:1 are used to make up the missing amount.

[0059] Comparative Example 5

[0060] The difference between Comparative Example 5 and Example 1 is that the total mass of the composite coupling agent remains unchanged, and the mass ratio of the composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate and heptadecafluorodecyltrimethoxysilane is 1:1.3:0.5.

[0061] Comparative Example 6

[0062] The difference between Comparative Example 6 and Example 1 is that the total mass of the composite coupling agent remains unchanged, and the mass ratio of the composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate and heptadecafluorodecyltrimethoxysilane is 1.3:0.5:1.

[0063] Comparative Example 7

[0064] The difference between Comparative Example 7 and Example 1 is that the total mass of the composite coupling agent remains unchanged, and the mass ratio of the composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate and heptadecafluorodecyltrimethoxysilane is 0.5:1:1.3.

[0065] Comparative Example 8

[0066] The difference between Comparative Example 8 and Example 1 is that no hydrophobic white carbon black is added, and an equal amount of organic modified montmorillonite is used to make up the missing amount.

[0067] Comparative Example 9

[0068] The difference between Comparative Example 9 and Example 1 is that no organic modified montmorillonite is added, and an equal amount of hydrophobic silica is used to make up for the missing amount.

[0069] Performance Testing

[0070] The composite method of the anti-caking agent and potassium chloride granular fertilizer comprises the following steps: adding the anti-caking agents of Examples 1-3 and Comparative Examples 1-9 to a stirring device respectively through a feeder, mixing them evenly with potassium chloride granules, and then conveying and packaging them through a conveyor belt and a finished product scraper. The anti-caking agent is added to the potassium chloride granular fertilizer in an amount of 0.1wt% to obtain an anti-caking potassium chloride granular fertilizer.

[0071] Each group of anti-caking potassium chloride granular fertilizers was placed at 60°C and 95% humidity for 2 hours, and then dried in a vacuum drying oven for 2 hours. The dried compound fertilizer was vibrated on a vibrating sieve machine for 15 minutes (the vibrating frequency and other test conditions were the same among the test groups), and the sieve residue was obtained by calculation. 1 (%) = m 1 / m 0 ×100%; where m 1 is the weight of the residue, m 0 is the original weight of each group of anti-caking potassium chloride granular fertilizer before the test. The specific test results are shown in Table 1.

[0072] At the same time, each group of anti-caking potassium chloride granular fertilizers was sealed and stored at 55°C (humidity was the same as the natural environment, without special treatment) for 60 days, the caking materials were weighed, and the caking rate was calculated, which was recorded as J 2 , agglomeration rate J 2 (%) = m 2 / m 0 ×100%; where m 2 is the weight of the residue, m 0 is the original weight of each group of anti-caking potassium chloride granular fertilizer before the test. The specific test results are shown in Table 1.

[0073] Table 1 Agglomeration rate of each group of anti-caking potassium chloride granular fertilizer under different conditions

[0074] Group / Performance <![CDATA[J 1 / %]]> <![CDATA[J 2 / %]]> Example 1 4.0 2.1 Example 2 4.7 2.5 Example 3 4.3 2.3 Comparative Example 1 25.2 23.4 Comparative Example 2 19.1 17.2 Comparative Example 3 19.2 17.5 Comparative Example 4 19.5 17.6 Comparative Example 5 8.7 7.9 Comparative Example 6 8.1 7.2 Comparative Example 7 8.2 7.4 Comparative Example 8 11.5 9.3 Comparative Example 9 27.4 25.1

[0075] It can be seen from Table 1 that, combined with the data of Example 1 and Comparative Examples 1-4, the type of coupling agent has a great influence on the high temperature stability and room temperature stability of the anti-caking agent. When bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearoyl titanate isopropyl ester and heptadecafluorodecyl trimethoxysilane are used in combination, the anti-caking performance of the product is better. When any one of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearoyl titanate isopropyl ester and heptadecafluorodecyl trimethoxysilane is missing, the performance of the anti-caking agent decreases.

[0076] Combining the data of Example 1 and Comparative Examples 5-7, it can be seen that when the mass ratio of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate and heptadecafluorodecyltrimethoxysilane is (1-1.5):1:(0.5-0.6), the high temperature stability and room temperature stability of the anti-caking agent reach a better level.

[0077] Combining the data of Example 1 and Comparative Examples 8-9, it can be seen that the caking agent of the present invention is a composite of hydrophobic silica and organic modified montmorillonite, and small-particle silica is embedded in the layered structure of montmorillonite, increasing the interlayer spacing of montmorillonite and further reducing the adsorption of water molecules, thereby improving the hydrophobic properties of the anti-caking agent, thereby improving the performance of the anti-caking agent.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An anti-caking agent for potassium chloride granules, characterized in that The invention comprises the following components in parts by weight: 50-60 parts of organic modified montmorillonite and 20-30 parts of hydrophobic white carbon black; wherein the organic modified montmorillonite comprises the following raw materials: montmorillonite, a composite coupling agent and an initiator; the mass ratio of the montmorillonite, the composite coupling agent and the initiator is (1-1.5):1:(0.02-0.06); the composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, isopropyl triisostearyl titanate and heptadecafluorodecyl trimethoxysilane in a mass ratio of (1-1.5):1:(0.5-0.6); the particle size of the hydrophobic white carbon black is less than the particle size of the organic modified montmorillonite.

2. The anti-caking agent for potassium chloride granules according to claim 1, characterized in that The initiator is dicumyl peroxide.

3. The anti-caking agent for potassium chloride granules according to claim 1, characterized in that The mesh size of the montmorillonite is 200-300 meshes; and / or the mesh size of the hydrophobic white carbon black is 400-600 meshes.

4. The anti-caking agent for potassium chloride granules according to claim 1, characterized in that The composite coupling agent is a composition of bis-(3-(triethoxysilane)propyl)-tetrasulfide, triisostearyl titanate isopropyl and heptadecafluorodecyl trimethoxysilane in a mass ratio of 1.3:1:0.

5.

5. A method for preparing an anti-caking agent for potassium chloride granules according to any one of claims 1 to 4, comprising the following steps: S1, dispersing montmorillonite in anhydrous ethanol and stirring evenly, adding a composite coupling agent and an initiator to react, after the reaction is completed, filtering, washing to neutrality, and drying to obtain an organic modified montmorillonite; S2. Ball-milling the organic modified montmorillonite and the hydrophobic white carbon black to obtain an anti-caking agent for the potassium chloride particles.

6. The preparation method according to claim 5, characterized in that: The amount of anhydrous ethanol added is 1-2 times the total mass of montmorillonite, the composite coupling agent and the initiator.

7. The preparation method according to claim 5, characterized in that: In step S1, the reaction temperature is 70-90° C. and the reaction time is 2-3 hours.

8. The method for preparing an anti-caking agent for potassium chloride granules according to claim 5, characterized in that: In the step S1, the organic modified montmorillonite and the hydrophobic white carbon black are ball-milled to 600-700 meshes.

9. Use of the anti-caking agent for potassium chloride granules according to any one of claims 1 to 4 in the preparation of potassium chloride granular fertilizer.

10. The use according to claim 9, characterized in that The anti-caking agent for the potassium chloride granules is added in an amount of 0.1-0.5 wt % in the potassium chloride granule fertilizer.