Anti-blocking agent for water-soluble fertilizer and preparation method of anti-blocking agent

Abstract

The invention discloses an anti-blocking agent for a water-soluble fertilizer and a preparation method of the anti-blocking agent. The anti-blocking agent is prepared from the following raw materials in parts by weight: 60-80 parts of nanoscale silicon dioxide, 20-30 parts of sodium metasilicate pentahydrate and 2-7 parts of micron-sized silicon dioxide. The particle size of the nanoscale silicon dioxide is 5-20 nm, and the specific surface area of the nanoscale silicon dioxide is 200-300 m / g; the particle size of the sodium metasilicate pentahydrate is 50-100 microns; the particle size of the micron-sized silicon dioxide is 5-15 microns, and the specific surface area of the micron-sized silicon dioxide is 150-200 m / g. The water-soluble fertilizer inorganic anti-blocking agent has the advantage of good preparation effect, and solves the problems that in the preparation process of an existing water-soluble fertilizer inorganic anti-blocking agent, various inorganic raw materials are inconvenient to uniformly mix, all components in the anti-blocking agent are not uniformly distributed, a local area is easily lack of a moisture absorption inhibition and isolation layer, the overall anti-blocking efficiency is reduced, and even if a sufficient amount of the anti-blocking agent is added, the anti-blocking effect is poor. And the problem of obvious caking still may occur.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of fertilizer processing, in particular to an anti-caking agent for water-soluble fertilizer and a preparation method thereof. BACKGROUND

[0002] The anti-caking agent for water-soluble fertilizer is a special additive added to water-soluble fertilizer, which mainly prevents the adhesion and caking of the fertilizer during storage and transportation, thereby maintaining the loose and flowable nature of the fertilizer and ensuring its easy use and uniform application. Water-soluble fertilizer is usually made of high-purity water-soluble salts, which have certain hygroscopicity. When the environmental humidity is high or the storage conditions are poor, the fertilizer will absorb moisture in the air and form a very thin solution film on the surface. When the moisture evaporates, the dissolved salts will recrystallize and form "liquid bridges" or "crystal bridges" between the fertilizers, causing the fertilizers to adhere together and eventually caking.

[0003] The anti-caking agent forms a hydrophobic protective film on the surface of the fertilizer, reducing the absorption of moisture in the air by the fertilizer, fundamentally inhibiting moisture absorption, and preventing or weakening the adhesion between the fertilizers due to moisture dissolution-recrystallization. Common types of anti-caking agents include inorganic, organic and composite types. Inorganic types include diatomaceous earth, kaolin, talc, silicon dioxide, etc. They mainly act as physical isolating agents, adsorbing on the surface of the fertilizer to increase the distance between the fertilizers and prevent direct contact.

[0004] The existing inorganic anti-caking agent for water-soluble fertilizer is not convenient for uniform mixing of multiple inorganic raw materials during preparation, the components in the anti-caking agent are unevenly distributed, which can easily lead to a lack of moisture absorption inhibition and isolation layer in local areas, resulting in a decrease in overall anti-caking efficiency. Even if a sufficient amount is added, obvious caking may still occur. SUMMARY

[0005] The application aims to provide an anti-caking agent for water-soluble fertilizer and a preparation method thereof, which has the advantage of good preparation effect, and solves the problem of the existing inorganic anti-caking agent for water-soluble fertilizer, which is not convenient for uniform mixing of multiple inorganic raw materials during preparation, the components in the anti-caking agent are unevenly distributed, which can easily lead to a lack of moisture absorption inhibition and isolation layer in local areas, resulting in a decrease in overall anti-caking efficiency. Even if a sufficient amount is added, obvious caking may still occur.

[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme: an anti-caking agent for water-soluble fertilizer, comprising the following raw materials in parts by weight:

[0007] 60-80 parts of nanoscale silicon dioxide, 20-30 parts of sodium metasilicate pentahydrate, and 2-7 parts of micrometer-scale silicon dioxide;

[0008] The nano-sized silicon dioxide has a particle size of 5-20 nm and a specific surface area of 200-300 m2 / g;

[0009] The sodium metasilicate pentahydrate has a particle size of 50-100 μm;

[0010] The micron-sized silicon dioxide has a particle size of 5-15 μm and a specific surface area of 150-200 m2 / g;

[0011] The nano-sized silicon dioxide, the sodium metasilicate pentahydrate and the micron-sized silicon dioxide account for 0.3%-0.8% of the total mass of the water-soluble fertilizer, and are uniformly sprayed in an atomized form into the water-soluble fertilizer.

[0012] A preparation method of the anti-caking agent for the water-soluble fertilizer comprises the following steps:

[0013] S1, the nano-sized silicon dioxide is treated by in-situ hydroxylation to enhance its hydrophilicity and dispersion stability, the micron-sized silicon dioxide is selected as high-purity spherical precipitated silicon dioxide to reduce the friction between the fertilizers and improve the flowability, and the sodium metasilicate pentahydrate is subjected to double functionalization treatment, i.e., firstly micronized to 50-100 μm, and then microencapsulated by sodium alginate and chitosan to construct a pH-responsive slow-release structure, so that it slowly releases to adjust the surface microenvironment during storage, and rapidly disintegrates in water;

[0014] S2, the nano-sized and micron-sized silicon dioxide are vacuum dried at 60°C for 2 hours to completely remove the physically adsorbed water and prevent agglomeration during mixing, and the microencapsulated sodium metasilicate is screened through a standard sieve of 150-300 meshes to ensure the consistency of the particle size and remove the caked fertilizer;

[0015] S3, the raw materials are mixed by using a mixer, i.e., the micron-sized silicon dioxide and the microencapsulated sodium metasilicate are firstly added into a mixing cavity in the mixer, and are preliminarily dispersed by running at a low speed of 30 rpm for 3 minutes, then the dried nano-sized silicon dioxide is added into the mixing cavity, and the rotating speed is gradually increased to 100 rpm, and the mixing is continuously performed for 12-15 minutes to uniformly distribute the ultrafine powder by using stirring mixing;

[0016] S4, the mixed anti-caking agent is added at the stage when the water-soluble fertilizer is completed, and the addition amount is 0.3%-0.8% of the total mass of the water-soluble fertilizer, when the atomized spraying is performed, the anti-caking agent is premixed with 0.1% of food-grade fumed silicon dioxide flow aid, and is uniformly sprayed on the surface of the flowing fertilizer by using a Venturi nozzle under a negative pressure fluidization state to realize single-fertilizer-grade accurate coating and improve the anti-caking efficiency, the mixing time is 3-5 minutes to ensure uniform distribution, and the aluminum-plastic composite film automatic heat sealing packaging should be performed immediately after the addition to prevent secondary moisture absorption;

[0017] S5, the water-soluble fertilizer to which the anti-caking agent is applied is subjected to anti-caking performance testing, water-solubility testing and irrigation system compatibility testing. When the anti-caking performance testing is performed, the water-soluble fertilizer to which the anti-caking agent is added is stored in an environment of 30 DEG C and 75% relative humidity for 60 days, and the caking rate is tested to be less than 2%.

[0018] Preferably, the mixing machine in S3 comprises a mixing tank, a support is rotatably connected to the surface of the mixing tank, and a base is fixedly installed at the bottom of the support.

[0019] Preferably, the support and the base are rotatably connected with a transmission shaft through bearings, a speed reducer motor is fixedly installed at the top of the base, and a first belt transmission mechanism is installed on the surface of the output shaft of the speed reducer motor and the transmission shaft.

[0020] Preferably, the surface of the transmission shaft and one end of the mixing tank are provided with a second belt transmission mechanism, and the first belt transmission mechanism, the transmission shaft and the second belt transmission mechanism transmit power from the speed reducer motor to one end of the mixing tank to drive the mixing tank to rotate forward and backward.

[0021] Preferably, the mixing tank comprises a tank body and a frame body, the tank body is fixedly installed inside the frame body, shafts are fixedly installed on the left and right sides of the frame body, the shafts are rotatably connected with the support through bearings, and the shafts are connected with the second belt transmission mechanism.

[0022] Preferably, a reinforcing ring is fixedly sleeved on the surface of the tank body, and the reinforcing ring is located at the bottom, the middle and the top of the surface of the tank body.

[0023] Preferably, a tank cover is movably connected to the top of the tank body, a fastening plate is fixedly installed on the top of the frame body through bolts, the fastening plate is located at the top of the tank cover to fix the tank cover, a motor is fixedly installed at the bottom of the tank body, an output shaft of the motor extends into the inner cavity of the tank body and is provided with a stirring structure, and the stirring structure stirs and mixes the micron-sized silicon dioxide, sodium metasilicate pentahydrate and nano-sized silicon dioxide in the mixing cavity in the tank body.

[0024] Preferably, the stirring mechanism comprises a rotating disc, the rotating disc is located at the bottom of the inner cavity of the tank body and is rotatably connected thereto, the output shaft of the motor is fixedly connected with the rotating disc, a first stirring rod and a second stirring rod are fixedly installed on the top of the rotating disc, the second stirring rod and the first stirring rod are located on the left and right sides of the inner cavity of the tank body, and a plurality of scattering rods are fixedly installed on the side opposite to the second stirring rod and the first stirring rod.

[0025] Preferably, as a preparation method of the anti-caking agent for water-soluble fertilizer of the present application, the first stirring rod is rotatably connected with a swing rod at the top of the inner side, the swing rod is rotatably connected with a stirring ball chain at the bottom, the stirring ball chain comprises connecting ropes, a plurality of stirring balls are installed on the connecting ropes, a first sliding sleeve is movably sleeved on the surface of the swing rod, a traction rod is rotatably connected with the first sliding sleeve, a second sliding sleeve is rotatably connected with one end of the traction rod, a sliding rail is movably sleeved in the second sliding sleeve, and the sliding rail is fixedly installed on the inner side of the second stirring rod.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] 1. The present application builds a multi-scale synergistic anti-caking system by scientifically proportioning nano- and micro-sized silicon dioxide and soluble metasilicate sodium pentahydrate, significantly improving the anti-caking performance of water-soluble fertilizer. Nano-sized silicon dioxide has a super-high specific surface area, can quickly adsorb trace amounts of moisture on the surface of the fertilizer, effectively inhibits the formation of "liquid bridges" due to moisture absorption, and prevents caking from the source. At the same time, nano- and micro-sized silicon dioxide forms a multi-level physical isolation layer on the surface of the fertilizer, increases the distance between the fertilizers, blocks the crystal crosslinking, and realizes the steric hindrance effect. The metasilicate sodium pentahydrate dissolves and adheres to the surface of the fertilizer in the presence of trace amounts of moisture, adjusts the interfacial tension and surface energy, further inhibits ion migration and recrystallization, and enhances the durability of anti-caking. The synergistic effect of the three makes the water-soluble fertilizer maintain good looseness during long-term storage in high-temperature and high-humidity environments, significantly improving the product stability and user experience.

[0028] 2. All components of the present application are inorganic, soluble or dispersible materials, the addition amount is only 0.3%-0.8% of the total mass of the water-soluble fertilizer, and it is uniformly sprayed in the form of atomization to ensure uniform coating and no local enrichment. The anti-caking agent is completely dissolved in water, has no residue, does not block the drip irrigation or sprinkler system, is compatible with the needs of modern precision agriculture, has stable raw material sources and high safety, has no adverse effects on soil and crops, is suitable for large-scale production of high-purity and high-quality water-soluble fertilizers, has the advantages of simple process, controllable cost, environmental protection and high efficiency, effectively solves the problems of easy residue, difficult mixing and influence on water solubility of traditional anti-caking agents, and has good application prospect and industrialization value. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a preparation flowchart of the present application;

[0030] Figure 2 It is a schematic diagram of the mixing machine of the present application;

[0031] Figure 3 It is a schematic diagram of the mixing tank of the present application;

[0032] Figure 4 It is a sectional view of the mixing tank of the present application.

[0033] In the figure: 1, mixing tank; 2, support; 3, base; 4, first belt drive; 5, transmission shaft; 6, speed reducer motor; 7, second belt drive; 101, tank body; 102, tank cover; 103, fastening plate; 104, frame body; 105, rotating shaft; 106, motor; 107, reinforcing ring; 108, rotating disc; 109, stirring ball chain; 110, second stirring rod; 111, traction rod; 112, second sliding sleeve; 113, sliding rail; 114, swing rod; 115, first sliding sleeve; 116, first stirring rod; 117, dispersing rod. DETAILED DESCRIPTION

[0034] Example 1

[0035] A kind of anti-caking agent for water-soluble fertilizer, comprising the following raw materials by weight fraction:

[0036] 60-80 parts of nanoscale silicon dioxide, 20-30 parts of sodium metasilicate pentahydrate, 2-7 parts of micron grade silicon dioxide;

[0037] The particle size of nanoscale silicon dioxide is 5-20 nm, and the specific surface area is 200-300 m² / g;

[0038] The particle size of sodium metasilicate pentahydrate is 50-100 μm;

[0039] The particle size of micron grade silicon dioxide is 5-15 μm, and the specific surface area is 150-200 m² / g;

[0040] Nanoscale silicon dioxide, sodium metasilicate pentahydrate and micron grade silicon dioxide account for 0.3%-0.8% of the total mass of water-soluble fertilizer, and are uniformly sprayed in the form of atomization into the water-soluble fertilizer.

[0041] The technical solution constructs a multi-scale synergistic anti-caking system by scientifically proportioning nanoscale and micron grade silicon dioxide and soluble sodium metasilicate pentahydrate, significantly improves the anti-caking performance of water-soluble fertilizer, nanoscale silicon dioxide has a super high specific surface area, can quickly adsorb trace moisture on the surface of the fertilizer, effectively inhibits the "liquid bridge" formed by moisture absorption, and prevents caking from the source. At the same time, nanoscale and micron grade silicon dioxide form a multi-level physical isolation layer on the surface of the fertilizer, increase the distance between the fertilizers, block the crystal crosslinking, realize the steric hindrance effect, sodium metasilicate pentahydrate dissolves and adheres to the surface of the fertilizer in the presence of trace moisture, adjusts the interfacial tension and surface energy, further inhibits ion migration and recrystallization, enhances the anti-caking durability, and the synergistic effect of the three makes the water-soluble fertilizer maintain good looseness during long-term storage in a high temperature and high humidity environment, significantly improves the product stability and user experience.

[0042] In addition, all components of the scheme are inorganic, soluble or dispersible materials, the addition amount is only 0.3%-0.8% of the total mass of water-soluble fertilizer, and is uniformly sprayed in the form of atomization, ensuring uniform coating and no local enrichment, the anti-caking agent is completely dissolved in water, no residue, no blockage of drip irrigation or sprinkler irrigation system, compatible with modern agricultural precision fertilization needs, stable raw material source, high safety, no adverse effects on soil and crops, suitable for large-scale production of high-purity and high-quality water-soluble fertilizer, with the advantages of simple process, controllable cost, environmental protection and high efficiency, effectively solving the problems of traditional anti-caking agents such as easy residue, difficult mixing and affecting water solubility, with good application prospect and industrialization value.

[0043] Example 2

[0044] Please refer to Figures 1-4 A preparation method of an anti-caking agent for water-soluble fertilizer, comprising the following steps:

[0045] S1, the nano-sized silicon dioxide is treated by in-situ hydroxylation by gas phase method to enhance its hydrophilicity and dispersion stability, the micro-sized silicon dioxide is selected as high-purity spherical precipitated silicon dioxide to reduce the friction between fertilizers and improve the flowability, the sodium metasilicate pentahydrate is subjected to double functionalization treatment, first micronized to 50-100 μm, and then microencapsulated by sodium alginate and chitosan to construct a pH-responsive slow-release structure, so that it slowly releases in storage to adjust the surface microenvironment, and rapidly disintegrates in water;

[0046] S2, the nano-sized and micro-sized silicon dioxide are dried at 60°C for 2 hours under vacuum to completely remove the physically adsorbed water and prevent agglomeration during mixing, and the microencapsulated sodium metasilicate is screened by a standard sieve of 150-300 meshes to ensure the consistency of particle size and remove caked fertilizers;

[0047] S3, the raw materials are mixed by a mixer, the micro-sized silicon dioxide and the microencapsulated sodium metasilicate are first added to the mixing cavity inside the mixer, and are mixed at a low speed of 30 rpm for 3 minutes to achieve preliminary dispersion, then the dried nano-sized silicon dioxide is added to the mixing cavity, and the speed is gradually increased to 100 rpm, and the mixing is continued for 12-15 minutes to achieve uniform distribution of ultra-fine powder by stirring and mixing;

[0048] S4, the mixed anti-caking agent is added at the stage of completing the mixing of water-soluble fertilizer, the addition amount is 0.3%-0.8% of the total mass of water-soluble fertilizer, when atomized spraying, the anti-caking agent is pre-mixed with 0.1% food-grade fumed silica flow aid, and is uniformly sprayed on the surface of flowing fertilizer under negative pressure fluidization state through a venturi nozzle, to achieve single fertilizer grade precision coating and improve the anti-caking efficiency, the mixing time is 3-5 minutes to ensure uniform distribution, and the aluminum-plastic composite film should be automatically heat-sealed and packaged immediately after addition to prevent secondary moisture absorption;

[0049] S5, the water-soluble fertilizer to which the anti-caking agent is applied is subjected to anti-caking performance testing, water-solubility testing and irrigation system compatibility testing. When the anti-caking performance testing is performed, the water-soluble fertilizer to which the anti-caking agent is added is stored in an environment of 30 DEG C and 75% relative humidity for 60 days, and the caking rate is less than 2%.

[0050] Further, when the water-solubility testing is performed on the water-soluble fertilizer to which the anti-caking agent is applied, 10 g of the sample is dissolved in 100 mL of clean water, and after standing for 5 minutes, the sample is completely dissolved without precipitation or suspension. When the irrigation system compatibility testing is performed, the solution of the water-soluble fertilizer is filtered through a 120-mesh stainless steel filter screen without clogging, and the filtrate is clear and transparent.

[0051] The technical solution significantly improves the stability, uniformity and long-term effectiveness of the anti-caking agent through functionalization treatment of raw materials and fine process control. The nanoscale silicon dioxide treated by in-situ hydroxylation through the gas phase method has stronger hydrophilicity and anti-aggregation ability, can efficiently adsorb water and uniformly distribute on the surface of the fertilizer, effectively inhibits the formation of liquid bridges, and the high-purity spherical micron-scale silicon dioxide significantly reduces the cohesion of the powder and improves the flowability, which is conducive to subsequent mixing and spraying. The key innovation is to micronize the sodium metasilicate pentahydrate and coat it with a sodium alginate-chitosan double-layer microcapsule to construct a pH-responsive slow-release structure, so that it slowly releases during storage to adjust the microenvironment on the surface of the fertilizer and inhibit the formation of crystal bridges, and rapidly disintegrates when it comes into contact with water to avoid long-term contact of the alkaline component with the ammonium nitrogen volatilization or the precipitation of trace elements. The design takes into account the anti-caking effect and the stability of fertilizer nutrients, realizes the dual goals of "storage anti-caking and application complete dissolution", and is especially suitable for high-end water-soluble fertilizer products containing sensitive nutrients.

[0052] In the preparation and application process, vacuum drying, screening treatment and gradient mixing process are used to ensure that the components are fully dispersed and uniformly mixed, effectively preventing the agglomeration and local enrichment of nanomaterials, improving batch stability, using fluidized bed gas flow atomization spraying technology combined with food-grade fumed silica flow agent to realize single-fertilizer-level precise coating of the anti-caking agent on the surface of the fertilizer, significantly improving the coverage efficiency and the durability of the anti-caking agent. It has been verified that the caking rate of the treated water-soluble fertilizer is less than 2% after being stored at 30 DEG C and 75% relative humidity for 60 days, and it is completely water-soluble without precipitation. It passes through a 120-mesh filter screen without clogging, fully meeting the stringent requirements of drip irrigation and sprinkler irrigation systems for flowability and purity. The method is controllable, environmentally friendly and safe, and has high efficiency and industrial feasibility, providing a reliable solution for long-term storage and efficient application of high-quality water-soluble fertilizers.

[0053] Referring to Table 1, Table 1 is a comparison table of the anti-caking agent of the present application and ordinary anti-caking agents;

[0054] Performance indicators The technical solution (improved anti-caking agent) Common anti-caking agent Accelerated storage conditions 30°C, 75% RH, 60 days 30°C, 75% RH, 60 days Caking rate ≤1.8% 5.2%–9.6% Hand loose Loose with light pressure, no hard block Partially caked hard Water solubility (10g / 100mL water) Completely dissolved, no precipitation after 5 minutes, solution transmittance ≥98% Slow dissolution, visible trace of suspended matter, solution transmittance 85%-90% Filtering performance (120 mesh filter) Filtering time: ≤30 seconds; no blockage; clear and transparent filtrate Filtering time: 60-90 seconds; local filter blockage; slightly turbid filtrate Mixing uniformity (RSD value) Relative standard deviation (RSD) of component distribution ≤2.5% RSD ≥6.8%, obvious local enrichment Batch stability (5 consecutive batches) Caking rate fluctuation range: 1.3%-1.8% Caking rate fluctuation range: 5.0%-10.2% Effect on ammonium nitrogen stability (pH change) Surface pH slowly rises from 7.8 to 8.2 (60 days), nitrogen loss rate <1.5% Surface pH rises to above 9.0, nitrogen volatilization loss rate >4.0% Flowability (resting angle) Resting angle ≤32°, good flowability Resting angle ≥40°, easy bridging and blockage Suitable fertilization system Precision systems such as drip irrigation, sprinkler irrigation, and unmanned aerial spraying are fully compatible Only suitable for common spreading, drip irrigation systems require additional filtration

[0055] Table 1

[0056] Further, the mixing machine in S3 comprises a mixing tank 1, a support 2 is rotatably connected to the surface of the mixing tank 1, and a base 3 is fixedly installed at the bottom of the support 2.

[0057] Further, a transmission shaft 5 is rotatably connected to the support 2 and the base 3 through bearings, a speed reducer motor 6 is fixedly installed at the top of the base 3, and a first belt transmission mechanism 4 is installed on the surface of the output shaft of the speed reducer motor 6 and the transmission shaft 5.

[0058] Further, a second belt transmission mechanism 7 is installed on the surface of the transmission shaft 5 and one end of the mixing tank 1, and the first belt transmission mechanism 4, the transmission shaft 5 and the second belt transmission mechanism 7 drive the mixing tank 1 to rotate forward and backward by transmitting the power of the speed reducer motor 6 to one end of the mixing tank 1.

[0059] Further, the mixing tank 1 comprises a tank body 101 and a frame body 104, the tank body 101 is fixedly installed inside the frame body 104, rotating shafts 105 are fixedly installed on the left and right sides of the frame body 104, the rotating shafts 105 are rotatably connected to the support 2 through bearings, and the rotating shafts 105 are connected to the second belt transmission mechanism 7.

[0060] Further, a reinforcing ring 107 is fixedly sleeved on the surface of the tank body 101, and the reinforcing ring 107 is located at the bottom, the middle and the top of the surface of the tank body 101.

[0061] Further, a tank cover 102 is movably connected to the top of the tank body 101, a fastening plate 103 is fixedly installed on the top of the frame body 104 by bolts, the fastening plate 103 is located at the top of the tank cover 102 to fix the tank cover 102, a motor 106 is fixedly installed at the bottom of the tank body 101, the output shaft of the motor 106 extends into the inner cavity of the tank body 101 and is provided with a stirring structure, and the stirring structure stirs and mixes micron-sized silicon dioxide, sodium metasilicate pentahydrate and nano-sized silicon dioxide in the mixing cavity inside the tank body 101.

[0062] Further, the stirring mechanism comprises a rotating disc 108, the rotating disc 108 is located at the bottom of the inner cavity of the tank body 101 and is rotatably connected thereto, the output shaft of the motor 106 is fixedly connected to the rotating disc 108, a first stirring rod 116 and a second stirring rod 110 are fixedly installed on the top of the rotating disc 108, the second stirring rod 110 and the first stirring rod 116 are located on the left and right sides of the inner cavity of the tank body 101, and a plurality of dispersing rods 117 are fixedly installed on the side opposite to the second stirring rod 110 and the first stirring rod 116.

[0063] Further, the inside top of the first stirring rod 116 is rotationally connected with a swing rod 114, the bottom of the swing rod 114 is rotationally connected with a stirring ball chain 109, the stirring ball chain 109 comprises a connecting rope, a plurality of stirring balls are mounted on the connecting rope, the surface of the swing rod 114 movably sheaths a first sliding sleeve 115, the surface of the first sliding sleeve 115 is rotationally connected with a traction rod 111, one end of the traction rod 111 is rotationally connected with a second sliding sleeve 112, the inside of the second sliding sleeve 112 movably sheaths a sliding rail 113, and the sliding rail 113 is fixedly installed in the inside of the second stirring rod 110.

[0064] When the raw materials are mixed, firstly, the pretreated micron-sized silicon dioxide and microencapsulated sodium metasilicate pentahydrate are added into the tank body 101 from the tank cover 102 at the top of the tank body 101 into the tank body 101 inside the mixing tank 1, then the tank cover 102 is closed and fixed by bolts through the fastening plate 103, the sealing of the mixing process is ensured, the reduction motor 6 is started, the output shaft drives the transmission shaft 5 to rotate through the first belt transmission mechanism 4, the transmission shaft 5 transmits power to the rotating shaft 105 at one end of the mixing tank 1 through the second belt transmission mechanism 7, so that the whole frame body 104 and the tank body 101 inside it reciprocate around the rotating shaft 105 on the support 2, realizing the overall overturning movement of the tank body, promoting the macro mixing of the materials, at the same time, the motor 106 at the bottom of the tank body 101 is started, the output shaft drives the rotating disc 108 to rotate, the rotating disc 108 drives the first stirring rod 116 and the second stirring rod 110 to rotate in the tank cavity, the dispersing rod 117 on the side wall shears and disperses the powder agglomerates, in the rotating process of the first stirring rod 116, the swing rod 114 at the inside top thereof moves, through the linkage of the first sliding sleeve 115 and the traction rod 111, the traction rod 111 pushes the second sliding sleeve 112 to reciprocate along the sliding rail 113 fixed in the inside of the second stirring rod 110, so as to drive the swing rod 114 to periodically swing, and further drive the stirring ball chain 109 to irregularly swing in the tank body 101, the stirring balls on the stirring ball chain 109 disturb and disperse the powder in the dead angle area, under the overall swinging of the tank 1, the rotating shearing of the stirring rod and the flexible disturbance of the stirring ball chain 109, the micron-sized silicon dioxide, the sodium metasilicate pentahydrate and the nanometer-sized silicon dioxide are efficiently and uniformly dispersed and mixed in the mixing cavity, the agglomeration of the nanometer material is avoided, after mixing for 12-15 minutes, the reduction motor 6 and the motor 106 are stopped, the tank cover 102 is opened, and the prepared anti-caking agent powder is taken out, the preparation is completed, and the reinforcing ring 107 strengthens the structure of the bottom, the middle end and the top of the tank body 101 during the whole process, so as to ensure the stability and sealing performance of the tank body 101 under repeated swinging and stirring.

[0065] Through the innovative design of the mixing machine, the efficient and uniform mixing of micron-sized silicon dioxide, sodium metasilicate pentahydrate and nano-sized silicon dioxide is realized, which significantly improves the preparation quality and production efficiency of the anti-caking agent. First, the mixing tank 1 is rotatably connected to the support 2 through the rotating shaft 105, and the power of the reduction motor 6 is transmitted to the mixing tank 1 through the first belt transmission mechanism 4 and the second belt transmission mechanism 7, so that the mixing tank 1 swings forward and backward on the support 2. This overall overturning movement promotes the uniform distribution of the material on a macro scale, avoiding local accumulation or agglomeration. At the same time, the reinforcing ring 107 is fixedly sleeved on the bottom, middle and top of the tank body 101, which enhances the stability of the tank body structure and ensures the sealing and safety under severe motion. Secondly, the stirring structure inside the tank body 101 includes the rotating disc 108 driven by the motor 106, the first stirring rod 116 and the second stirring rod 110, which disperses and mixes the powder on a microscopic level through rotational shearing. The design of the dispersing rod 117 can effectively break up the soft agglomerates that may form, further improving the mixing uniformity. In addition, the unique stirring ball chain 109 generates irregular disturbances in the tank cavity through the linkage system composed of the swing rod 114, the first sliding sleeve 115, the traction rod 111, the second sliding sleeve 112 and the sliding rail 113, which is particularly suitable for processing materials in dead corner areas of the tank, ensuring that all raw materials are fully mixed. Finally, the cooperation of the tank cover 102 and the fastening plate 103 not only facilitates the feeding and discharging operations, but also ensures the sealing during the mixing process, preventing dust from spilling out and ensuring the safety and cleanliness of the operating environment. In summary, the mixing machine realizes efficient and uniform mixing of raw materials through multi-level and multi-dimensional mixing mechanisms combined with structural optimization design, providing solid technical support for the preparation of high-quality anti-caking agents.

[0066] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An anti-caking agent for water-soluble fertilizers, characterized in that, The ingredients include the following parts by weight: 60-80 parts of nano-sized silica, 20-30 parts of sodium metasilicate pentahydrate, and 2-7 parts of micron-sized silica; The particle size of nano-sized silica is 5-20 nm, and the specific surface area is 200-300 m² / g; The particle size of sodium metasilicate pentahydrate is 50-100 μm; Micron-sized silica has a particle size of 5-15 μm and a specific surface area of ​​150-200 m² / g; Nano-sized silica, sodium metasilicate pentahydrate, and micron-sized silica account for 0.3%-0.8% of the total mass of the water-soluble fertilizer and are evenly sprayed into the water-soluble fertilizer in the form of atomization.

2. A method for preparing an anti-caking agent for water-soluble fertilizers, applicable to the anti-caking agent for water-soluble fertilizers described in claim 1, characterized in that, Includes the following steps: S1. Nano-sized silica is treated with in-situ hydroxylation using a gas-phase method to enhance its hydrophilicity and dispersion stability. Micron-sized silica uses high-purity spherical precipitated silica to reduce friction between fertilizers and improve fluidity. Sodium metasilicate pentahydrate undergoes dual functionalization treatment: first, it is micronized to 50-100μm, and then microencapsulated with sodium alginate and chitosan to construct a pH-responsive slow-release structure, which allows it to slowly release during storage to regulate the surface microenvironment, while rapidly disintegrating in water. S2, nano-sized and micron-sized silica were vacuum dried at 60℃ for 2 hours to completely remove physically adsorbed water and prevent agglomeration during mixing. Microencapsulated sodium metasilicate was screened through a 150-300 mesh standard sieve to ensure particle size consistency and remove clumps of fertilizer. S3. Use a mixer to mix the raw materials. First, add micron-sized silica and microencapsulated sodium metasilicate into the mixing chamber inside the mixer. Mix for 3 minutes at a low speed of 30 rpm to achieve initial dispersion. Then, add dried nano-sized silica into the mixing chamber and gradually increase the speed to 100 rpm. Continue mixing for 12-15 minutes to achieve uniform distribution of ultrafine powder by stirring. S4. The anti-caking agent is added after the water-soluble fertilizer has been mixed. The amount added is 0.3%-0.8% of the total mass of the water-soluble fertilizer. When atomizing and spraying, a fluidized bed airflow atomization spraying process is used. The anti-caking agent is premixed with 0.1% of food-grade fumed silica flow aid and then evenly sprayed onto the surface of the flowing fertilizer through a Venturi nozzle under negative pressure fluidization to achieve precise coating of single fertilizer and improve anti-caking efficiency. The mixing time is 3-5 minutes to ensure uniform distribution. After addition, the fertilizer should be automatically heat-sealed with aluminum-plastic composite film immediately to prevent secondary moisture absorption. S5. Conduct anti-caking performance tests, water solubility tests, and irrigation system compatibility tests on water-soluble fertilizers with added anti-caking agents. When conducting anti-caking performance tests, store the water-soluble fertilizers with added anti-caking agents in an environment of 30℃ and 75% relative humidity for 60 days. The caking rate of the tested fertilizers should be less than 2%.

3. The method for preparing an anti-caking agent for water-soluble fertilizer according to claim 2, characterized in that: The mixer in S3 includes a mixing tank (1), a bracket (2) is rotatably connected to the surface of the mixing tank (1), and a base (3) is fixedly installed at the bottom of the bracket (2).

4. The method for preparing an anti-caking agent for water-soluble fertilizer according to claim 3, characterized in that: The bracket (2) and the base (3) are rotatably connected by bearings to a drive shaft (5). A geared motor (6) is fixedly installed on the top of the base (3). A first belt drive mechanism (4) is installed on the output shaft of the geared motor (6) and the surface of the drive shaft (5).

5. The method for preparing an anti-caking agent for water-soluble fertilizer according to claim 4, characterized in that: A second belt drive mechanism (7) is installed on the surface of the drive shaft (5) and one end of the mixing tank (1). The first belt drive mechanism (4), the drive shaft (5) and the second belt drive mechanism (7) transmit the power of the reduction motor (6) to one end of the mixing tank (1) to drive the mixing tank (1) to rotate back and forth.

6. The method for preparing an anti-caking agent for water-soluble fertilizer according to claim 5, characterized in that: The mixing tank (1) includes a tank body (101) and a frame (104). The tank body (101) is fixedly installed inside the frame (104). Rotating shafts (105) are fixedly installed on the left and right sides of the frame (104). The rotating shafts (105) are rotatably connected to the support (2) through bearings. The rotating shafts (105) are connected to the second belt drive mechanism (7).

7. The method for preparing an anti-caking agent for water-soluble fertilizer according to claim 6, characterized in that: A reinforcing ring (107) is fixedly fitted on the surface of the tank (101), and the reinforcing ring (107) is located at the bottom, middle and top of the surface of the tank (101).

8. A method for preparing an anti-caking agent for water-soluble fertilizer according to claim 7, characterized in that: The top of the tank (101) is movably connected to the tank cover (102), and the top of the frame (104) is fixedly installed with a fastening plate (103) by bolts. The fastening plate (103) is located on the top of the tank cover (102) to fix the tank cover (102). The bottom of the tank (101) is fixedly installed with a motor (106). The output shaft of the motor (106) extends to the inner cavity of the tank (101) and is equipped with a stirring structure. The stirring structure stirs and mixes the micron-sized silica, sodium metasilicate pentahydrate and nano-sized silica in the mixing chamber inside the tank (101).

9. A method for preparing an anti-caking agent for water-soluble fertilizer according to claim 8, characterized in that: The stirring mechanism includes a turntable (108), which is located at the bottom of the inner cavity of the tank (101) and is rotatably connected to it. The output shaft of the motor (106) is fixedly connected to the turntable (108). A first stirring rod (116) and a second stirring rod (110) are fixedly installed on the top of the turntable (108). The second stirring rod (110) and the first stirring rod (116) are located on the left and right sides of the inner cavity of the tank (101). Several dispersing rods (117) are fixedly installed on the opposite side of the second stirring rod (110) and the first stirring rod (116).

10. A method for preparing an anti-caking agent for water-soluble fertilizer according to claim 9, characterized in that: The top inner side of the first stirring rod (116) is rotatably connected to a swing rod (114), and the bottom of the swing rod (114) is rotatably connected to a stirring ball chain (109). The stirring ball chain (109) includes a connecting rope, and several stirring balls are installed on the connecting rope. The surface of the swing rod (114) is movably fitted with a first sliding sleeve (115). The surface of the first sliding sleeve (115) is rotatably connected to a traction rod (111). One end of the traction rod (111) is rotatably connected to a second sliding sleeve (112). The inside of the second sliding sleeve (112) is movably fitted with a slide rail (113), and the slide rail (113) is fixedly installed inside the second stirring rod (110).

Images