Attapulgite-based chemical fertilizer anti-caking agent and preparation method thereof

Abstract

The invention relates to the technical field of chemical fertilizer anti-caking agents, and discloses an attapulgite-based chemical fertilizer anti-caking agent and a preparation method thereof.The preparation method specifically comprises the steps that urea, dimethyl phosphite, a formaldehyde aqueous solution, itaconic acid and tripotassium citrate serve as raw materials, and a Mannich reaction, a dehydration reaction and an esterification reaction are conducted in sequence to prepare an alkenyl nitrogen phosphorus potassium compound nutrition component; the preparation method comprises the following steps: carrying out ring-opening reaction on hydroxyl groups on the surface of attapulgite and epoxy groups in allyl glycidyl ether to prepare alkenylated attapulgite; the preparation method comprises the following steps: by taking alkenylated attapulgite and an alkenylated nitrogen-phosphorus-potassium compound nutrient component as main raw materials and N, N-methylenebisacrylamide as a cross-linking agent, preparing functionalized attapulgite by adopting a solution polymerization method under the action of an initiator; functionalized attapulgite and fatty alcohol-polyoxyethylene ether are used as raw materials and are mixed, ground and sieved to prepare the chemical fertilizer anti-caking agent. The fertilizer prepared by adding the chemical fertilizer anti-caking agent prepared by the invention shows excellent anti-caking performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical fertilizer anti-caking agent, and particularly relates to a palygorskite-based chemical fertilizer anti-caking agent and a preparation method thereof. BACKGROUND

[0002] In modern production, more than half of the energy required for plant growth comes from chemical fertilizers, which have become a key condition for crop growth and an important guarantee for yield improvement. However, chemical fertilizers have always been plagued by caking. Caking of chemical fertilizers can significantly reduce the utilization rate of fertilizer efficiency. After caking, the granules of chemical fertilizers are prone to dissolution-recrystallization imbalance, leading to uneven distribution of nutrients. After being applied to the soil, it cannot achieve uniform release. Excess nutrients in some areas cause soil salinization, while nutrient deficiency in some areas causes crop growth deficiency. At the same time, caked chemical fertilizers bring great inconvenience to agricultural operations: large hard lumps are difficult to break, not only increasing the labor intensity, but also possibly damaging the fertilization machinery; small caked particles are easy to block the spray head, the conveying pipeline and other equipment parts, affecting the continuity and uniformity of mechanized fertilization, and reducing the operation efficiency. In the storage and transportation process, caked chemical fertilizers will stick together, causing waste of storage space, increasing the loss in the transportation process, and at the same time affecting the commodity appearance quality of chemical fertilizers and reducing market acceptance.

[0003] In addition to taking measures during the production, packaging and storage of chemical fertilizers, adding an anti-caking agent to the chemical fertilizer is the most effective anti-caking method. The commonly used anti-caking agents include inert powders, non-surface active organic compounds and surfactants. However, the use of inert powders (such as diatomite, kaolin, talc, palygorskite, aluminum silicate, limestone, etc.) alone has poor effect on compound fertilizers prone to caking, and greatly increases the dust content of chemical fertilizers, reducing the effective content of chemical fertilizers. Non-surface active organic compounds (such as paraffin, mineral oil, various resin polymers, etc.) have strict requirements on the environment temperature. When the environment temperature is not high, their anti-caking effect is good, but when the environment temperature is higher than 70℃, their anti-caking effect decreases rapidly, and even causes more serious caking problems. Surfactants can be divided into cationic (such as fatty amine salt, acid salt, quaternary ammonium salt, etc.), anionic (such as alkyl sulfonate and its intermediate alkyl sulfonyl chloride, alkyl benzene sulfonate, alpha-olefin sulfonate and fatty acid ammonium, etc.) and non-ionic (such as fatty alcohol polyoxyethylene ether, alkyl phenol polyoxyethylene ether, fatty acid polyoxyethylene ester and alkyl amine polyoxyethylene ether) according to their polarity structure. Due to the different polarity of surfactants, the anti-caking effect on different types of chemical fertilizers is different.

[0004] Research has found that palygorskite is an inert powder with a chain transition structure of fibrous texture layer and a developed pore system. It not only has a large specific surface area but also has a strong physical isolation effect. It can also effectively absorb the moisture in the chemical fertilizer, reduce the frequency of dissolution-crystallization process of fertilizer salt solution, and thus reduce the caking of chemical fertilizers.

[0005] However, the use of attapulgite alone to solve the isolation effect of fertilizer particles is limited, and it is difficult to prevent the mutual connection between the crystal grains for a long time. The compound anti-caking agent is composed of two or more substances, which utilizes the synergistic effect of different surfactants to increase the surface activity, overcomes the locality and limitation of single substance, so that it is easier to be adsorbed on the surface of fertilizer, and a relatively dense hydrophobic layer is formed. For example, the surfactant is used in combination with inert powder, the inert powder can mechanically separate the fertilizer particles, and the surfactant reduces the surface tension, and through optimization, a better anti-caking effect can be achieved. SUMMARY

[0006] The application provides an attapulgite-based fertilizer anti-caking agent and a preparation method thereof. The anti-caking agent is prepared from functionalized attapulgite and fatty alcohol polyoxyethylene ether surfactant as raw materials by mixing, grinding and sieving. The fertilizer prepared by adding the anti-caking agent exhibits excellent anti-caking performance.

[0007] To achieve the above-mentioned purpose, the application adopts the following technical scheme:

[0008] An attapulgite-based fertilizer anti-caking agent, the anti-caking agent formula is:

[0009] Functionalized attapulgite, 70-90 parts by weight;

[0010] Fatty alcohol polyoxyethylene ether, 10-30 parts by weight;

[0011] The functionalized attapulgite is prepared from alkenyl attapulgite and alkenyl nitrogen-phosphorus-potassium compound nutrient component as raw materials, N,N-methylene bisacrylamide as a crosslinking agent, and an initiator under the action of an initiator through a solution polymerization method;

[0012] The alkenyl nitrogen-phosphorus-potassium compound nutrient component is prepared by esterification reaction of 1 mole equivalent of carboxyl groups in the alkenyl nitrogen-phosphorus nutrient component and 1 mole equivalent of hydroxyl groups in the tripotassium citrate under the catalysis of a protonic acid;

[0013] The alkenyl nitrogen-phosphorus nutrient component is prepared from urea, phosphite, aqueous formaldehyde solution and itaconic acid through Mannich reaction and dehydration reaction.

[0014] Preferably, the formula of the functionalized attapulgite is: 90-110 parts by weight of alkenyl attapulgite; 0.1-0.5 parts by weight of N,N-methylene bisacrylamide crosslinking agent; 5-15 parts by weight of alkenyl nitrogen-phosphorus-potassium compound nutrient component; 1-2 parts by weight of initiator; 60-100 parts by weight of water.

[0015] Preferably, the initiator is one of potassium persulfate and sodium persulfate.

[0016] Preferably, the protic acid is one of p-toluenesulfonic acid, trifluoromethanesulfonic acid.

[0017] Preferably, the phosphite is one of dimethyl phosphite, diethyl phosphite.

[0018] A preparation method of the attapulgite-based fertilizer anti-caking agent comprises the following steps: mixing attapulgite and fatty alcohol polyoxyethylene ether, grinding and sieving after uniform mixing, and obtaining the fertilizer anti-caking agent.

[0019] Preferably, the preparation method of the alkenyl attapulgite is as follows: based on an epoxy-hydroxyl ring-opening reaction mechanism, using attapulgite and allyl glycidyl ether as raw materials, and obtaining the alkenyl attapulgite.

[0020] Preferably, the mesh number of the sieving is 600-1000 mesh.

[0021] Preferably, the caking rate of the fertilizer prepared after adding the anti-caking agent is 1-3%.

[0022] The present application has the following beneficial effects:

[0023] Using urea, dimethyl phosphite and formaldehyde aqueous solution as raw materials, a Mannich reaction is first performed, then a dehydration reaction with itaconic acid is performed, and finally an esterification reaction with tri-potassium citrate is performed, so that an alkenyl nitrogen-phosphorus-potassium compound nutrient component is prepared;

[0024] Based on an epoxy-hydroxyl ring-opening reaction mechanism, using attapulgite and allyl glycidyl ether as raw materials, an alkenyl attapulgite is prepared.

[0025] Using the alkenyl attapulgite and the alkenyl nitrogen-phosphorus-potassium compound nutrient component as main raw materials, and N,N-methylene bisacrylamide as a crosslinking agent, a functional attapulgite is prepared by solution polymerization under the action of an initiator.

[0026] The attapulgite is coated with an organic layer containing nitrogen, phosphorus and potassium elements, which has the dual functions of anti-caking and nutrient supply, can synergistically improve the utilization efficiency of fertilizers, optimize the soil environment and help crop growth; on the other hand, the organic modified attapulgite has good compatibility with the fatty alcohol polyoxyethylene ether surfactant, and the dispersibility of the attapulgite is enhanced, so that the attapulgite changes from hydrophilic to hydrophobic, which plays a better isolation protection role on the fertilizer, thereby further effectively preventing the caking of the fertilizer.

[0027] Using attapulgite and fatty alcohol polyoxyethylene ether as raw materials, a fertilizer anti-caking agent is prepared by mixing and grinding and sieving processes.

[0028] The experimental results prove that the fertilizer prepared by adding the fertilizer anti-caking agent prepared by the present application has excellent anti-caking performance. DETAILED DESCRIPTION

[0029] Example One:

[0030] Preparation of the alkenylated nitrogen phosphorus potassium complex nutrient component includes the following steps:

[0031] Step One: Preparation of the alkenylated nitrogen phosphorus nutrient component, the preparation mechanism is: using urea, dimethyl phosphite, aqueous formaldehyde and itaconic acid as raw materials, first Mannich reaction, then dehydration reaction, to prepare the alkenylated nitrogen phosphorus nutrient component, the specific experimental steps are as follows: 11 g of dimethyl phosphite and 60 mL of anhydrous ethanol are mixed uniformly in a 250 mL three-necked flask, 1 g of concentrated hydrochloric acid catalyst and 12 g of 37 wt% aqueous formaldehyde solution are added, stirred for 1 h, then 6 g of urea is added, the temperature is raised to 110 ℃, and refluxed for 8 h. After the reaction is completed, 9.1 g of the product prepared above is weighed and placed in a reactor, the temperature of the system is raised to 130 ℃, and after the product is in a molten state, 6.6 g of itaconic acid is added, stirred for 30 s, cooled and pulverized to prepare the alkenylated nitrogen phosphorus nutrient component;

[0032] Step Two: Preparation of the alkenylated nitrogen phosphorus potassium complex nutrient component, the preparation mechanism is: through the esterification reaction of the carboxyl group in the alkenylated nitrogen phosphorus nutrient component and the hydroxyl group in the trisodium citrate, the alkenylated nitrogen phosphorus potassium complex nutrient component is prepared, and the specific experimental steps are as follows: 10 g of citric acid is added to 50 mL of water, and 22 g of 40% mass fraction of potassium hydroxide solution is added dropwise under stirring, the reaction temperature is controlled at 40 ℃, and the pH value of the system is monitored at the same time. When the pH value is stable at 8, trisodium citrate is prepared.

[0033] In a 250 mL four-necked flask equipped with a stirrer, a thermometer, a water separator and a reflux condenser, 5.9 g of alkenylated nitrogen phosphorus nutrient component and 50 mL of anhydrous ethanol are added, mixed uniformly, and then 6.2 g of trisodium citrate and 0.12 g of p-toluenesulfonic acid are added. After the addition is completed, heating is started until the temperature in the flask reaches 110 ℃, and reflux reaction is carried out for 5 h. After the reaction is completed, filtration, washing and drying at 50 ℃ for 8 h are carried out to prepare the alkenylated nitrogen phosphorus potassium complex nutrient component.

[0034] Example Two:

[0035] Preparation of the alkenylated attapulgite includes the following steps:

[0036] First Step: 10 g of attapulgite (specification 200 mesh) is added to a mixture of 25 mL of water and 25 mL of anhydrous ethanol, then the hydrogen ion concentration is adjusted to 5 M using concentrated hydrochloric acid, heated to refluxing state under stirring, and refluxed for 5 h. After stopping heating, the upper solution is removed by centrifugation, washed, and placed in a 120 ℃ oven for drying to prepare the pretreated attapulgite;

[0037] Second step: 10 g of pretreated attapulgite was ultrasonically dispersed in 50 mL of N,N-dimethylformamide, 3 g of allyl glycidyl ether was added, mechanically stirred to be uniform, the temperature was raised to 140°C, and the reaction was carried out for 3 h. After the reaction, filtration, washing, and drying at 50°C to constant weight were carried out, to obtain the allylated attapulgite.

[0038] Example Three:

[0039] (1) The raw material formula for preparing the functionalized attapulgite I is as follows:

[0040] 100 parts by weight of allylated attapulgite;

[0041] 0.3 parts by weight of N,N-methylene bisacrylamide crosslinking agent;

[0042] 5 parts by weight of allylated nitrogen, phosphorus and potassium composite nutrient component;

[0043] 1.8 parts by weight of potassium persulfate initiator;

[0044] 80 parts by weight of water;

[0045] The preparation method of the functionalized attapulgite I comprises the following steps: according to the formula of the functionalized attapulgite I, the ingredients are prepared, the allylated attapulgite is added to water, ultrasonic dispersion is carried out for 30 min, then N,N-methylene bisacrylamide, the allylated nitrogen, phosphorus and potassium composite nutrient component, and the potassium persulfate are added, and mixed uniformly. The temperature of the system is raised to 75°C, and the stirring reaction is carried out for 3 h. The whole process is carried out under nitrogen protection. After the reaction, drying is carried out in a vacuum drying oven at 60°C to constant weight, to obtain the functionalized attapulgite I.

[0046] (2) The raw material formula for preparing the functionalized attapulgite II is as follows:

[0047] 100 parts by weight of allylated attapulgite;

[0048] 0.3 parts by weight of N,N-methylene bisacrylamide crosslinking agent;

[0049] 10 parts by weight of allylated nitrogen, phosphorus and potassium composite nutrient component;

[0050] 1.8 parts by weight of potassium persulfate initiator;

[0051] 80 parts by weight of water;

[0052] The preparation method of the functionalized palygorskite II comprises the following steps: ingredients are prepared according to the formula of the functionalized palygorskite II, the alkenyl palygorskite is added into water, ultrasonic dispersion is carried out for 30 min, then N,N-methylene bisacrylamide, the alkenyl nitrogen, phosphorus and potassium compound nutrient component and potassium persulfate are added, mixing is carried out, the temperature of the system is increased to 75 DEG C, stirring reaction is carried out for 3 h, the whole process is carried out under nitrogen protection, after the reaction is completed, drying is carried out in a vacuum drying box at 60 DEG C until the constant weight, and the functionalized palygorskite II is prepared.

[0053] (3) The preparation of the functionalized palygorskite III, the raw material formula is:

[0054] 100 parts by weight of alkenyl palygorskite;

[0055] 0.3 parts by weight of N,N-methylene bisacrylamide crosslinking agent;

[0056] 15 parts by weight of alkenyl nitrogen, phosphorus and potassium compound nutrient component;

[0057] 1.8 parts by weight of potassium persulfate initiator;

[0058] 80 parts by weight of water;

[0059] The preparation method of the functionalized palygorskite III comprises the following steps: ingredients are prepared according to the formula of the functionalized palygorskite III, the alkenyl palygorskite is added into water, ultrasonic dispersion is carried out for 30 min, then N,N-methylene bisacrylamide, the alkenyl nitrogen, phosphorus and potassium compound nutrient component and potassium persulfate are added, mixing is carried out, the temperature of the system is increased to 75 DEG C, stirring reaction is carried out for 3 h, the whole process is carried out under nitrogen protection, after the reaction is completed, drying is carried out in a vacuum drying box at 60 DEG C until the constant weight, and the functionalized palygorskite III is prepared.

[0060] Example four:

[0061] The functionalized palygorskite is used in cooperation with the fatty alcohol polyoxyethylene ether surfactant, the localness and the limitation of single substance are overcome, and better anti-caking effect is realized.

[0062] (1) The preparation of the fertilizer anti-caking agent I, the raw material formula is:

[0063] 80 parts by weight of the functionalized palygorskite I;

[0064] 20 parts by weight of the fatty alcohol polyoxyethylene ether surfactant;

[0065] The preparation method of the fertilizer anti-caking agent I comprises the following steps: ingredients are prepared according to the formula of the fertilizer anti-caking agent I, the functionalized palygorskite I and the fatty alcohol polyoxyethylene ether are mixed, after uniform mixing, grinding is carried out through an 800-mesh standard sieve, and the fertilizer anti-caking agent I is prepared.

[0066] (2) The preparation of the fertilizer anti-caking agent II, the raw material formula is:

[0067] 80 parts by weight of functionalized palygorskite II;

[0068] 20 parts by weight of fatty alcohol polyoxyethylene ether surfactant;

[0069] The preparation method of the chemical fertilizer anti-caking agent II comprises the following steps: ingredients are prepared according to the formula of the chemical fertilizer anti-caking agent II, the functionalized palygorskite II and the fatty alcohol polyoxyethylene ether are mixed, and after being uniformly mixed, the mixture is ground through an 800-mesh standard sieve to obtain the chemical fertilizer anti-caking agent II.

[0070] (3) The chemical fertilizer anti-caking agent III is prepared from the following raw materials:

[0071] 80 parts by weight of functionalized palygorskite III;

[0072] 20 parts by weight of fatty alcohol polyoxyethylene ether surfactant;

[0073] The preparation method of the chemical fertilizer anti-caking agent III comprises the following steps: ingredients are prepared according to the formula of the chemical fertilizer anti-caking agent III, the functionalized palygorskite and the fatty alcohol polyoxyethylene ether are mixed, and after being uniformly mixed, the mixture is ground through an 800-mesh standard sieve to obtain the chemical fertilizer anti-caking agent III.

[0074] (4) Since the palygorskite that has not been subjected to surface organic modification is prone to agglomeration, which affects the anti-caking performance in the fertilizer, in order to verify that the anti-caking performance of the functionalized palygorskite is better than that of the palygorskite that has not been subjected to surface organic modification, the functionalized palygorskite is compounded with the palygorskite that has not been subjected to surface organic modification to prepare the chemical fertilizer anti-caking agent IV, and the raw material formula is as follows:

[0075] 40 parts by weight of functionalized palygorskite II;

[0076] 40 parts by weight of palygorskite (with a specification of 200 meshes);

[0077] 20 parts by weight of fatty alcohol polyoxyethylene ether surfactant;

[0078] The preparation method of the chemical fertilizer anti-caking agent VI comprises the following steps: ingredients are prepared according to the formula of the chemical fertilizer anti-caking agent IV, the functionalized palygorskite II, the palygorskite and the fatty alcohol polyoxyethylene ether are mixed, and after being uniformly mixed, the mixture is ground through an 800-mesh standard sieve to obtain the chemical fertilizer anti-caking agent IV.

[0079] (5) Since the palygorskite that has not been subjected to surface organic modification is prone to agglomeration, which affects the anti-caking performance in the fertilizer, in order to verify that the anti-caking performance of the functionalized palygorskite is better than that of the palygorskite that has not been subjected to surface organic modification, the functionalized palygorskite is compounded with the palygorskite that has not been subjected to surface organic modification to prepare the chemical fertilizer anti-caking agent V, and the raw material formula is as follows:

[0080] 30 parts by weight of functionalized palygorskite II;

[0081] 50 parts by weight of attapulgite (specification 200 mesh) ;

[0082] 20 parts by weight of fatty alcohol polyoxyethylene ether surfactant;

[0083] The preparation method of the chemical fertilizer anti-caking agent V comprises the following steps: according to the formula of the chemical fertilizer anti-caking agent V, ingredients are prepared, the functionalized attapulgite II, attapulgite and fatty alcohol polyoxyethylene ether are mixed, and after being uniformly mixed, the mixture is ground through an 800 mesh standard sieve to prepare the chemical fertilizer anti-caking agent V.

[0084] (6) Since the attapulgite without surface organic modification is prone to agglomeration, the anti-caking performance in the fertilizer is affected, in order to verify that the anti-caking performance of the functionalized attapulgite is better than that of the attapulgite without surface organic modification, the functionalized attapulgite is compounded with the attapulgite without surface organic modification to prepare a chemical fertilizer anti-caking agent VI, and the raw material formula is as follows:

[0085] 50 parts by weight of functionalized attapulgite II;

[0086] 30 parts by weight of attapulgite (specification 200 mesh) ;

[0087] 20 parts by weight of fatty alcohol polyoxyethylene ether surfactant;

[0088] The preparation method of the chemical fertilizer anti-caking agent VI comprises the following steps: according to the formula of the chemical fertilizer anti-caking agent VI, ingredients are prepared, the functionalized attapulgite II, attapulgite and fatty alcohol polyoxyethylene ether are mixed, and after being uniformly mixed, the mixture is ground through an 800 mesh standard sieve to prepare the chemical fertilizer anti-caking agent VI.

[0089] (7) Since the attapulgite without surface organic modification is prone to agglomeration, the anti-caking performance in the fertilizer is affected, in order to verify that the anti-caking performance of the functionalized attapulgite is better than that of the attapulgite without surface organic modification, the functionalized attapulgite is compounded with the attapulgite without surface organic modification to prepare a chemical fertilizer anti-caking agent VII, and the raw material formula is as follows:

[0090] 60 parts by weight of functionalized attapulgite II;

[0091] 20 parts by weight of attapulgite (specification 200 mesh) ;

[0092] 20 parts by weight of fatty alcohol polyoxyethylene ether surfactant;

[0093] The preparation method of the chemical fertilizer anti-caking agent VII comprises the following steps: according to the formula of the chemical fertilizer anti-caking agent VII, ingredients are prepared, the functionalized attapulgite II, attapulgite and fatty alcohol polyoxyethylene ether are mixed, and after being uniformly mixed, the mixture is ground through an 800 mesh standard sieve to prepare the chemical fertilizer anti-caking agent VII.

[0094] (8) The attapulgite without surface organic modification is easy to appear agglomeration phenomenon, which affects the anti-caking performance in the fertilizer. In order to verify that the anti-caking performance of the functional attapulgite is better than that of the attapulgite without surface organic modification, the functional attapulgite and the attapulgite without surface organic modification are compounded to prepare the fertilizer anti-caking agent VIII, and the raw material formula of the fertilizer anti-caking agent VIII is as follows:

[0095] 20 parts by weight of the functional attapulgite II;

[0096] 60 parts by weight of the attapulgite (the specification is 200 mesh);

[0097] 20 parts by weight of the fatty alcohol polyoxyethylene ether surfactant;

[0098] The preparation method of the fertilizer anti-caking agent VIII includes the following steps: ingredients are prepared according to the formula of the fertilizer anti-caking agent VIII, the functional attapulgite II, the attapulgite and the fatty alcohol polyoxyethylene ether are mixed, and then the mixture is ground through an 800-mesh standard sieve to prepare the fertilizer anti-caking agent VIII.

[0099] (9) The attapulgite without surface organic modification is easy to appear agglomeration phenomenon, which affects the anti-caking performance in the fertilizer. In order to verify that the anti-caking performance of the functional attapulgite is better than that of the attapulgite without surface organic modification, the functional attapulgite and the attapulgite without surface organic modification are compounded to prepare the fertilizer anti-caking agent IX, and the raw material formula of the fertilizer anti-caking agent IX is as follows:

[0100] 80 parts by weight of the attapulgite (the specification is 200 mesh);

[0101] 20 parts by weight of the fatty alcohol polyoxyethylene ether surfactant;

[0102] The preparation method of the fertilizer anti-caking agent IX includes the following steps: ingredients are prepared according to the formula of the fertilizer anti-caking agent IX, the functional attapulgite II, the attapulgite and the fatty alcohol polyoxyethylene ether are mixed, and then the mixture is ground through an 800-mesh standard sieve to prepare the fertilizer anti-caking agent IX.

[0103] Example Five:

[0104] (1) The preparation of the anti-caking fertilizer I includes the following steps:

[0105] 1000 parts of the fertilizer (30-0-5, the water content is 0.98%, and the fertilizer is provided by Shandong Shidunli Chemical Fertilizer Co., Ltd.) and 4 parts of the fertilizer anti-caking agent I are directly sent into a cooling roller by a screw conveyor, the anti-caking agent is fully attached to the surface of the fertilizer particles through the rolling of the cooling roller, and then the particles or powder with a particle size of less than 1 mm are filtered out to prepare the anti-caking fertilizer I.

[0106] (2) The preparation of the anti-caking fertilizer II includes the following steps:

[0107] Preparation of anti-caking fertilizer II, including the following steps:

[0108] (3) Preparation of anti-caking fertilizer III, including the following steps:

[0109] Preparation of anti-caking fertilizer III, including the following steps:

[0110] (4) Preparation of anti-caking fertilizer IV, including the following steps:

[0111] Preparation of anti-caking fertilizer IV, including the following steps:

[0112] (5) Preparation of anti-caking fertilizer V, including the following steps:

[0113] Preparation of anti-caking fertilizer V, including the following steps:

[0114] (6) Preparation of anti-caking fertilizer VI, including the following steps:

[0115] Preparation of anti-caking fertilizer VI, including the following steps:

[0116] (7) Preparation of anti-caking fertilizer VII, including the following steps:

[0117] Preparation of anti-caking fertilizer VII, comprising the following steps:

[0118] (8) Preparation of anti-caking fertilizer VIII, comprising the following steps:

[0119] Preparation of anti-caking fertilizer VIII, comprising the following steps:

[0120] (9) Preparation of anti-caking fertilizer IX, comprising the following steps:

[0121] Preparation of anti-caking fertilizer IX, comprising the following steps:

[0122] Performance test:

[0123] Anti-caking performance: 500 g of anti-caking fertilizer sample per bag, double-layer packaging with sealed film bag, 50 kg of weight is placed on the sample, and the sample is placed at room temperature for 30 days. The blank sample without the addition of fertilizer anti-caking agent is used as a control sample. The fertilizer after 30 days of packaging is taken out, and the bag is dropped once in the positive and negative directions at a height of 1 m from the ground. Then the fertilizer is sieved through a 5 mm sieve, and the caked and uncaked fertilizers are weighed and the caking rate is calculated: caking rate = (caked fertilizer mass / total mass of fertilizer in the sealed bag) x 100%;

[0124] The test results are shown in Table 1 below:

[0125] Table 1 Anti-caking performance results of fertilizer anti-caking agent

[0126] Product No. Caking rate (%) Anti-caking fertilizer I 1.6 Anti-caking fertilizer II 1.3 Anti-caking fertilizer III 1.1 Anti-caking fertilizer IV 3.8 Anti-caking fertilizer V 4.5 Anti-caking fertilizer VI 3.1 Anti-caking fertilizer VII 2.3 Anti-caking fertilizer VIII 5.2 Anti-caking fertilizer IX 8.4 Blank 33.2

[0127] From the experimental results of Table 1, it can be seen that the caking rates of the anti-caking fertilizer I, the anti-caking fertilizer II, the anti-caking fertilizer III, the anti-caking fertilizer IV, the anti-caking fertilizer V, the anti-caking fertilizer VI, the anti-caking fertilizer VII, the anti-caking fertilizer VIII and the anti-caking fertilizer IX are 1.6%, 1.3%, 1.1%, 3.8%, 4.5%, 3.1%, 2.3%, 5.2% and 8.4% respectively, while the caking rate of the control sample is 33.2%, indicating that the caking rate of the fertilizer after adding the anti-caking agent prepared by the application is significantly reduced, but the caking rate of the anti-caking fertilizer after compounding the functionalized palygorskite and the palygorskite without surface organic modification increases, indicating that the anti-caking performance of the functionalized palygorskite is superior to that of the palygorskite without surface organic modification, therefore, the fertilizer prepared after adding the anti-caking agent prepared by the application has excellent anti-caking performance.

Claims

1. An attapulgite-based fertilizer anti-caking agent, characterized in that, The anti-caking agent formula is: Functionalized palygorskite, 70-90 parts by weight; Fatty alcohol polyoxyethylene ether, 10-30 parts by weight; The functionalized palygorskite is prepared by solution polymerization with alkenylated palygorskite and alkenylated nitrogen-phosphorus-potassium compound nutrient component as raw materials, N,N-methylenebisacrylamide as crosslinking agent, and an initiator under the action of the initiator; The alkenylated nitrogen-phosphorus-potassium compound nutrient component is prepared by esterification reaction of 1 mole equivalent of carboxyl groups in the alkenylated nitrogen-phosphorus nutrient component with 1 mole equivalent of hydroxyl groups in the tripotassium citrate under the catalysis of a protonic acid; The alkenylated nitrogen-phosphorus nutrient component is prepared by Mannich reaction and dehydration reaction with urea, phosphite, aqueous formaldehyde solution, and itaconic acid as raw materials.

2. The attapulgite-based fertilizer anti-caking agent according to claim 1, characterized in that, The formula of the functionalized palygorskite is: 90-110 parts by weight of alkenylated palygorskite; 0.1-0.5 parts by weight of N,N-methylenebisacrylamide crosslinking agent; 5-15 parts by weight of alkenylated nitrogen-phosphorus-potassium compound nutrient component; 1-2 parts by weight of initiator; and 60-100 parts by weight of water.

3. The attapulgite-based fertilizer anti-caking agent according to claim 2, characterized in that, The initiator is one of potassium persulfate and sodium persulfate.

4. The attapulgite-based fertilizer anti-caking agent according to claim 1, characterized in that, The protonic acid is one of p-toluenesulfonic acid and triflic acid.

5. The attapulgite-based fertilizer anti-caking agent according to claim 1, characterized in that, The phosphite is one of dimethyl phosphite and diethyl phosphite.

6. A process for the preparation of an attapulgite-based fertilizer anti-caking agent according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: mixing palygorskite and fatty alcohol polyoxyethylene ether, grinding and sieving after uniform mixing, and preparing a chemical fertilizer anti-caking agent.

7. A process for the preparation of an attapulgite-based fertilizer anti-caking agent according to claim 6, characterized in that, The preparation method of the alkenylated palygorskite is based on the epoxy-hydroxyl ring-opening reaction mechanism, and the alkenylated palygorskite is prepared with palygorskite and allyl glycidyl ether as raw materials.

8. A process for the preparation of an attapulgite-based fertilizer anti-caking agent according to claim 6, characterized in that, The mesh number of the sieving is 600-1000.

9. A process for the preparation of an attapulgite-based fertilizer anti-caking agent according to claim 6, characterized in that, The caking rate of the fertilizer prepared after adding the anti-caking agent is 1-3%.