A ternary compound automatic floating weed control composition for agricultural use and its preparation method

Abstract

This invention discloses an agricultural ternary compound automatic floating herbicide composition and its preparation method, belonging to the field of pesticide and herbicide technology. The composition contains adjuvants such as bispyribac-sodium, oxadiazon, dicyclosulfuron, and a compound safener. The preparation method includes ultra-fine grinding, stepwise kneading and granulation, and sieving. This invention addresses the problem that existing safeners cannot simultaneously solve the issues of rice protection and soil residue damage. It covalently links bispyribac-sodium with fulvic acid. After application to paddy fields, the ester bonds are gradually hydrolyzed in the paddy field water or soil environment, releasing bispyribac-sodium fragments that improve rice's tolerance to herbicides. The fulvic acid skeleton adsorbs herbicide residues in the soil and promotes their degradation. The stepwise kneading process enriches the surface spreader and flotation agent within the particles, achieving automatic floating and spreading. This invention achieves the goals of weed control, rice protection, residue reduction, and soil improvement, solving the problems of weed control, subsequent crop safety, and soil improvement in a single application.

Description

Technical Field

[0001] This invention relates to the field of pesticide and herbicide technology, and in particular to an agricultural ternary compound automatic floating herbicide composition and its preparation method. Background Technology

[0002] The occurrence and damage of weeds in paddy fields are one of the important factors affecting rice yield and quality. Weeds such as barnyard grass, goosegrass, duckweed, and sedge compete with rice for sunlight, water, and nutrients, and in severe cases, can lead to yield reductions of more than 30%. Chemical weeding is currently the main method for controlling weeds in paddy fields. Among them, cyprodinil, oxadiazon, and sulfadiazon are three highly effective herbicides with complementary mechanisms of action and broad spectrum of weed control. Cyprodinil is a contact herbicide, absorbed through the roots and base of weeds, acting rapidly and showing good control efficacy against grasses, broadleaf weeds, and sedges, and exhibits no cross-resistance with existing herbicides. Oxarazon is highly effective against barnyard grass and has a long residual effect. Sulfadiazon has excellent control efficacy against stubborn weeds resistant to sulfonylurea herbicides. The combination of these three herbicides can achieve the effect of controlling multiple weeds in paddy fields with a single application.

[0003] However, the above three herbicides present two prominent problems in practical application. First, bispyribac-sodium and sulfadiazine have long residual periods in the soil, which may cause phytotoxicity to subsequent crops (such as wheat and rapeseed) after application, limiting their application in crop rotation fields. Second, rice is sensitive to all three herbicides to some extent, and is prone to phytotoxicity symptoms such as leaf yellowing and growth inhibition after application, especially under unfavorable climatic conditions such as low temperature and low light. Therefore, how to improve rice's tolerance to herbicides and reduce soil residues while ensuring weed control effectiveness is a pressing technical challenge in the field of chemical weed control in paddy fields.

[0004] To address these issues, existing technologies include the combination of safeners and herbicides. For example, combining glyphosate and pretilachlor can improve rice's tolerance to pretilachlor, while combining bispyribac-methyl and quizalofop-p-ethyl can accelerate the metabolic degradation of herbicides in rice. Furthermore, some studies have explored adding humic acid or fulvic acid to herbicides to reduce the bioavailability of residual herbicides in the soil through adsorption. However, existing technologies still have significant shortcomings: on the one hand, traditional safeners (such as glyphosate) only act on the detoxification metabolism of rice in the current season, offering no treatment for residual herbicides in the soil and failing to address the risk of phytotoxicity in subsequent crops; on the other hand, while humic acid or fulvic acid can adsorb residues, they lack synergistic design with the safener, operating independently with fragmented functions, and in practical applications, they suffer from problems such as high dosage and unstable effects. More importantly, there are currently no herbicide formulations that integrate safeners and residual adsorption and degradation functions into the same molecule, while simultaneously achieving floating diffusion and slow-release protection. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides an agricultural ternary compound automatic floating weed control composition and its preparation method.

[0006] The technical solutions provided by the embodiments of the present invention are as follows:

[0007] An agricultural auto-dispersible multi-component herbicide composition comprises the following components in parts by weight:

[0008] Bismuth subtilis: 0.2-10 parts;

[0009] Oxadiazon: 1-20 parts;

[0010] Bicyclosulfuron: 1-20 parts

[0011] Compound safety agent: 5-15 parts;

[0012] Dispersant: 2-10 parts;

[0013] Wetting agent: 1-10 parts;

[0014] Adhesive: 1-10 parts;

[0015] Water surface spreader: 2-20 parts;

[0016] Flotation agent: 2-30 parts;

[0017] Filler: 5-50 parts;

[0018] The composite safener is composed of fulvic acid and hydroxylated oxychloride covalently linked by ester bonds, and its preparation method includes:

[0019] S1. Add cyclohexidine, 6-bromo-1-hexanol, and potassium carbonate to dimethylformamide in a weight ratio of 1:1.2-1.5:1-1.5, react at 70-80℃ for 6-10 h, and then extract, dry, hydrolyze, and recrystallize to obtain hydroxylated cyclohexidine.

[0020] This reaction is a nucleophilic substitution reaction (SNAr). The chemical structure of pyrazine is 4,6-dichloro-2-phenylpyrimidine. The chlorine atoms at the 4- and 6-positions of the pyrimidine ring are affected by the electron-withdrawing inductive effect and the conjugation effect of the two nitrogen atoms on the ring, which makes it highly reactive and easily attacked and substituted by nucleophiles.

[0021] In the reaction system, potassium carbonate acts as an acid-binding agent, reacting with the hydroxyl group of 6-bromo-1-hexanol in an acid-base reaction to produce potassium 6-bromo-1-hexanol (RO-K). +The process converts the hydroxyl group into a more nucleophilic alkoxy anion. This alkoxy anion, acting as a nucleophile, can attack any highly reactive site on the 4- or 6-carbon atom of the glycidylpyrimidine ring (both have similar reactivity and no site selectivity) due to steric hindrance and stoichiometric control, forming an unstable tetrahedral intermediate. Subsequently, the intermediate eliminates the chloride ion, generating 4-(6-bromohexoxy)-6-chloro-2-phenylpyrimidine and 6-(6-bromohexoxy)-4-chloro-2-phenylpyrimidine. They have the same molecular formula and structure and identical chemical properties, so they do not need to be separated in subsequent esterification and hydrolysis reactions and can be used directly as a mixture.

[0022] The above mixture was extracted, dried, and then hydrolyzed at 50-60℃ under alkaline (sodium hydroxide) conditions for 2-4 hours. The bromine atom, being a good leaving group, underwent a nucleophilic substitution reaction (SN2) in the alkaline aqueous solution, resulting in the formation of a hydroxyl anion (OH-) in the water. - The bromide ion attacks the terminal primary carbon, departs, and forms a primary alcohol;

[0023] The above reaction formula is:

[0024]

[0025] S2. Fulvic acid, hydroxyl oxychloride, and 4-dimethylaminopyridine are dissolved in dimethylformamide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is added dropwise. The mixture is stirred at room temperature for 2 hours, then heated to 40°C and reacted for 12-16 hours. After acid precipitation, water washing, alcohol washing, and drying, the composite safer is obtained.

[0026] This reaction is an esterification reaction of carboxylic acids and alcohols, catalyzed by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl) and 4-dimethylaminopyridine (DMAP). The fulvic acid molecule contains a large number of carboxyl groups (-COOH), and the hydroxyl group of the pyrazine molecule contains a primary alcohol hydroxyl group (-OH) at the end. The two undergo an esterification reaction in the presence of a condensing agent to form an ester bond (-COO-), covalently linking the pyrazine fragment to the fulvic acid skeleton.

[0027] Activation mechanism of EDC·HCl:

[0028] EDC·HCl is a water-soluble carbodiimide condensing agent. The carbodiimide group (-N=C=N-) in its molecule first reacts with the carboxyl group of fulvic acid to generate an active O-acyl isourea intermediate. This intermediate has high reactivity and can be nucleophilically attacked by the hydroxyl group of glycyrrhizin to generate the target ester bond, while releasing water-soluble urea byproducts.

[0029] Catalytic mechanism of DMAP:

[0030] DMAP is a highly efficient nucleophilic catalyst. The dimethylamino group at the 4-position of its pyridine ring significantly enhances the nucleophilicity of the nitrogen atom. The catalytic cycle of DMAP is as follows: First, the pyridine nitrogen atom of DMAP attacks the carbonyl carbon of the O-acylisourea intermediate to generate a highly active acylpyridinium salt. The reactivity of this acylpyridinium salt is much higher than that of the O-acylisourea intermediate. Its carbonyl carbon is more positively charged and can be rapidly nucleophilically attacked by the hydroxyl group of glyphosate. The hydroxyl group of glyphosate attacks the carbonyl carbon of the acylpyridinium salt to generate the target ester bond. At the same time, DMAP is regenerated and water-soluble urea byproducts are released, entering the next catalytic cycle. The addition of DMAP significantly accelerates the esterification reaction rate, while inhibiting the formation of N-acylurea byproducts and improving the yield of the target product.

[0031]

[0032] The essence of the above esterification reaction is that the primary alcohol hydroxyl group (-OH) at the end of the hydroxyl group of pyrazine acts as a nucleophile to attack the carbonyl carbon of the fulvic acid carboxyl group after it is activated by EDC·HCl, and a nucleophilic addition-elimination reaction occurs to form an ester bond (-COO-), which covalently links the pyrazine fragment to the fulvic acid skeleton through a six-carbon linker arm.

[0033] The above steps use dimethylformamide (DMF) as a solvent, which has good solubility for both fulvic acid and hydroxylated oxalic acid, allowing the reaction to proceed in a homogeneous system. The reaction is first stirred at room temperature for 2 hours to fully activate the fulvic acid carboxyl groups with EDC·HCl; then the temperature is raised to 40°C and the reaction continues for 12-16 hours to promote the full formation of ester bonds.

[0034] After the reaction is complete, the reaction solution is added dropwise to a dilute hydrochloric acid aqueous solution to protonate the unreacted carboxyl groups on the fulvic acid backbone. When the pH is less than 3, the hydrogen bonds between and within fulvic acid molecules are strengthened, the charge is neutralized, the colloidal stability decreases, and aggregation occurs, resulting in the precipitation of the precipitate from the solution. The filter cake is washed sequentially with deionized water to remove water-soluble urea byproducts, residual EDC·HCl and its decomposition products, and DMAP hydrochloride; then washed with anhydrous ethanol to remove unreacted free hydroxyl groups to clethodim. After vacuum drying, the composite safener is obtained.

[0035] After the above steps, glyphosate is covalently linked to the fulvic acid skeleton through ester bonds. These ester bonds keep glyphosate anchored in the early stages of application, preventing it from being washed away by water quickly. When the compound safener disintegrates and disperses with the particles, the ester bonds are gradually hydrolyzed by microbial esterases or chemical hydrolysis in the water or soil environment. The released glyphosate can be absorbed by rice, which helps to improve its effective utilization rate.

[0036] The fulvic acid skeleton can be dispersed in paddy field water or soil before and after ester bond hydrolysis. Its carboxyl and phenolic hydroxyl groups can immediately adsorb free herbicide residues, forming a release-adsorption coupling mechanism. In addition, the covalent connection allows pyrazinamide and fulvic acid to coexist in the composition in a fixed stoichiometric ratio, avoiding spatial separation and ratio imbalance caused by differences in dissolution rate and diffusion rate during physical mixing. This design helps pyrazinamide and fulvic acid to play the roles of improving rice tolerance and adsorbing herbicide residues respectively in the same application system.

[0037] The dispersant is selected from one or more of polycarboxylate, naphthalene sulfonate, and lignin sulfonate;

[0038] The molecular structure of the dispersant contains multiple anionic groups (such as carboxylate and sulfonate groups). These anionic groups can be adsorbed onto the surface of the ultra-fine pulverized solid particles, so that the particle surface carries the same negative charge. The electrostatic repulsion between the same charges can effectively prevent the powder particles from secondary agglomeration after processing, storage and water disintegration, ensuring that the active ingredients of the herbicide are uniformly dispersed in the water.

[0039] The wetting agent is selected from one or more of alkyl sulfonates and alkyl sulfates;

[0040] Wetting agent molecules have a hydrophilic and lipophilic amphiphilic structure. Their hydrophobic end is adsorbed on the particle surface, while their hydrophilic end extends into the water. This can significantly reduce the surface tension of water. After the surface tension is reduced, water can more easily overcome the air resistance and hydrophobic effect on the particle surface and quickly penetrate into the particle interior, accelerating the water absorption and swelling process of the binder.

[0041] The binder is selected from one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, and sodium carboxymethyl starch;

[0042] The aforementioned polymer binder has good water solubility and film-forming properties. During the granulation process, it dissolves in water and binds the ultrafine powder, flotation agent, and filler together. After drying, it forms solid particles with a certain mechanical strength. When immersed in water, the hydroxyl and carboxyl groups on the binder molecular chain form hydrogen bonds with water molecules, causing the polymer chain segments to gradually expand, absorb water, and swell. The volume expansion generates internal stress. When the stress accumulates to exceed the strength of the particle structure, the particles disintegrate and break apart.

[0043] The water surface spreader is selected from one or more of hydrogenated castor oil, styrene-phenol polyoxyethylene ether, alkyl aryl polyoxyethylene polyoxypropylene ether, alkyl aryl methyl ether resin polyoxyethylene ether, and α-methyl benzyl polyoxyethylene ether;

[0044] Water surface spreaders are surfactants with low surface tension. After the particles enter the water, they quickly diffuse from the particle surface to the water surface, forming a monomolecular film. This locally reduces the surface tension of the water. The surface tension difference between the spreader-covered and uncovered areas generates Marangoni flow, which drives the particles on the water surface to move towards the periphery of the low surface tension area, thereby enabling the particles to automatically spread and be evenly distributed on the water surface.

[0045] The flotation agent is selected from one or more of hollow glass microspheres, cork powder, and porous starch;

[0046] The true density of hollow glass microspheres is 0.2-0.6 g / cm³. 3 The particle size is 30-100 μm, the cork powder has a particle size of 100-300 mesh, and the porous starch has a density of 0.4-0.8 g / cm³. 3 The particle size is 10-200μm;

[0047] Hollow glass microspheres have a hollow, spherical structure and a true density of only 0.2-0.6 g / cm³. 3 Its density is much less than that of water; cork flour comes from the bark of the cork oak tree, which has a natural porous honeycomb structure and a density of approximately 0.2-0.3 g / cm³. 3 After enzymatic hydrolysis or foaming treatment, porous starch forms numerous micropores inside, reducing its density to 0.4-0.8 g / cm³. 3 After these low-density materials are evenly dispersed inside the particles, the overall density of the particles is reduced to 0.6-0.9 g / cm³, thus ensuring that the particles can float on the water surface after being put into water.

[0048] The filler is selected from one or more of bentonite, soluble starch, diatomaceous earth, and potassium chloride;

[0049] Bentonite is a layered silicate mineral with an extremely strong water absorption and swelling capacity. After absorbing water, its volume can expand several to tens of times, making it a key aid in promoting particle disintegration. Soluble starch can not only act as a dilution carrier to increase particle volume, but its swelling properties after absorbing water can also assist in disintegration. Diatomaceous earth is rich in microporous structure and can act as an adsorption carrier to load effective ingredients and aids, preventing their precipitation. Potassium chloride is a water-soluble inorganic salt that dissolves rapidly in water, forming dissolution channels inside the particles, providing channels for water penetration and accelerating the disintegration process.

[0050] A method for preparing an agricultural self-dispersing multi-component compound herbicide composition further includes the following steps:

[0051] T1, Ultrafine Grinding:

[0052] The ingredients, including bispyribac-sodium, oxadiazon, bispyribac-sodium, a composite safener, a dispersant, a wetting agent, a binder, and some fillers, are mixed evenly according to the weight ratio described in claim 1, and then fed into an air jet mill for pulverization until the particle size of the solid particles in the powder is less than 20 μm, thus obtaining ultrafine powder.

[0053] The air jet mill uses compressed air or superheated steam as the power medium. The gas is accelerated to a supersonic jet through a Laval nozzle. The high-speed jet drives the material particles to collide, rub, and shear against each other in the grinding chamber. The impact and shear forces generated by the high-speed collisions between particles and between particles and the chamber wall act on the lattice defects inside the solid. When the local stress exceeds the strength limit of the material, the particles break apart. Due to the randomness of the gas jet and the complex flow field distribution in the grinding chamber, each particle undergoes multiple cycles of acceleration, collision, and re-acceleration in the grinding chamber. The particle size decreases continuously with the increase of the number of collisions. This step controls the particle size of the solid particles in the powder to below 20μm. This particle size range can ensure that the effective ingredients are evenly distributed inside the particles during the subsequent granulation process, and at the same time, it is conducive to the rapid dissolution and release of the effective ingredients after entering the water.

[0054] Dispersants and wetting agents are adsorbed onto the surface of newly generated particles during the pulverization process. Through electrostatic repulsion and steric hindrance, they prevent secondary agglomeration of ultrafine powder after pulverization. The binder, as part of the powder matrix, does not undergo hydration at this stage and is uniformly dispersed in the powder in a dry powder state, providing a binding skeleton for the subsequent kneading and granulation steps. The addition of some fillers plays a role in dilution, grinding aid, and dispersion isolation, preventing excessive aggregation of ultrafine powder.

[0055] The ultrafine powder obtained by air jet milling has the characteristics of narrow particle size distribution, fresh particle surface, large specific surface area and high uniformity of mixing of various components, providing high-quality powder raw materials for subsequent kneading and granulation steps;

[0056] T2, Stepwise kneading and granulation

[0057] T201. Add the ultrafine powder, the remaining filler, and water (10-25% of the total weight of the dry materials) into a kneader and knead for 15-30 minutes until uniform.

[0058] In this step, water acts as a solvent and plasticizer, first wetting the surface of the ultrafine powder particles. The dispersant and wetting agent dissolve upon contact with water, their hydrophilic groups combine with water molecules, and their hydrophobic groups adsorb onto the surface of the solid particles, reducing the solid-liquid interfacial tension and promoting uniform water penetration. The binder (carboxymethyl cellulose, hydroxypropyl methyl cellulose, etc.) gradually hydrates upon contact with water, and the polymer chain segments gradually unwind from a coiled state to form a three-dimensional network structure, "bridging" the dispersed ultrafine powder particles together and giving the material plasticity and viscosity. The addition of fillers can adjust the flowability and plasticity of the material and prevent excessive adhesion. The remaining fillers are added at this stage. Some fillers (such as bentonite) rapidly absorb water and expand upon contact with water, and the layered structure is stretched by water molecules, further increasing the volume and plasticity of the material. The mixing paddle of the kneader applies shear force and extrusion to the material, so that water, ultrafine powder, and fillers are fully mixed to form a wet material with uniform composition and good plasticity.

[0059] T202. Add the flotation agent to the kneader and continue kneading for 5-10 minutes.

[0060] The flotation agent is added in the later stage of the kneading process, and the kneading time is relatively short (5-10 min). The purpose is to make the flotation agent evenly dispersed in the wet material, while avoiding the flotation agent from breaking due to excessive kneading. Hollow glass microspheres have a hollow thin-walled structure, and cork powder has a porous honeycomb structure. Both are lightweight and brittle. If the kneading time is too long or the shear force is too large, the shell of the hollow microspheres may break, and the pore structure of the cork powder may be crushed, causing the flotation agent to fail. Therefore, step T202 is carried out after the basic kneading in T201. At this time, the material has good plasticity and uniformity, and only a short kneading time is needed to make the flotation agent evenly dispersed, while protecting the structural integrity of the flotation agent to the greatest extent.

[0061] T203. Add the water surface expander to the kneader and knead quickly for 3-5 minutes. Transfer the kneaded material to an extrusion granulator for granulation to obtain cylindrical wet granules. Place the granules in a dryer and dry at a temperature of 50-60℃ until the moisture content of the granules is ≤3%.

[0062] The water surface spreader is added in the final stage before granulation, and the kneading time is the shortest (only 3-5 minutes). The water surface spreader is mostly an oily or low-melting-point surfactant. Its function is to be distributed on the outermost layer of the particles. If it is added too early or the kneading time is too long, the water surface spreader may be excessively mixed into the particles, resulting in a decrease in its enrichment concentration on the particle surface. After being added to water, it cannot quickly diffuse to the water surface, affecting the spreading effect. Quick kneading for 3-5 minutes can make the water surface spreader evenly coat the surface of the wet material particles, forming a continuous spreader film.

[0063] After kneading, the wet material is fed into an extrusion granulator for granulation. The water surface expander is distributed on the outer layer of the granules and partially migrates to the surface of the granules during the granulation process. After drying, it forms a surface enrichment layer. During the drying process, the temperature is controlled at 50-60℃. This temperature can effectively remove moisture (drying to a moisture content ≤3%) without causing the decomposition or volatilization of the water surface expander. At the same time, it can prevent the flotation agent from breaking due to overheating. The dried granules have extremely low moisture content, which can prevent moisture absorption and clumping during storage and ensure the flowability and storage stability of the granules.

[0064] T3, Screening:

[0065] The dried granules are graded and sorted to remove oversized lumps and finely crushed particles, resulting in cylindrical granules with a diameter of 1.0-1.5 mm and a length of 3-8 mm, which are the finished floating granule agent.

[0066] After drying, the granules undergo extrusion granulation and fluidized bed drying. Due to the unevenness of the material during kneading, granulation, and drying, the particle size and length have a certain distribution range. There may also be a small amount of oversized clumps (formed by material adhesion) and fine pulverized particles (generated by particle edge wear or disintegration). Oversized clumps take too long to disintegrate after entering water, which may delay the release of active ingredients and affect the timely exertion of the herbicide. Fine pulverized particles have a higher specific gravity and may sink to the bottom quickly after entering water, failing to maintain a floating state for a sufficient time, thus affecting the uniform diffusion of the herbicide on the water surface. Therefore, it is necessary to classify and sort the granules using a vibrating screen.

[0067] Preferably, the mass ratio of fulvic acid, hydroxyl oxychloride, and 4-dimethylaminopyridine is 1:(0.4-0.8):(0.05-0.15), and the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.5-2.5 times the mass of fulvic acid.

[0068] Fulvic acid is derived from weathered coal, with a number-average molecular weight of 1000-2000 Da and a carboxyl content of 6-8 mmol / g.

[0069] Acid precipitation is performed using 5-10 wt% dilute hydrochloric acid.

[0070] Preferably, the disintegration time of the floating granules after entering the water is 8-12 minutes, the active ingredients and water-soluble additives are completely released or dissolved in the water, and the flotation agent controls the overall specific gravity of the floating granules to be 0.6-0.9.

[0071] Compared with the prior art, the beneficial effects of the present invention are:

[0072] 1. This invention covalently links oxychloride and fulvic acid via ester bonds, creating a novel fulvic acid-oxychloride ester composite safener. Upon introduction into water, the ester bonds in the soil gradually hydrolyze, allowing the oxychloride fragments to be absorbed by rice, thus enhancing rice's ability to metabolize herbicides and effectively mitigating herbicide damage during the current season. The fulvic acid skeleton disperses in the paddy field, adsorbing and immobilizing residual herbicides such as cyprodinil and sulfadiazine through its abundant carboxyl and phenolic hydroxyl groups, reducing their bioavailability and preventing herbicide damage to subsequent crops. Simultaneously, fulvic acid, as a soil conditioner, may assist in the degradation of residual herbicides by promoting microbial activity. This design expands the traditional safener's single function of protecting only the current season's rice to a four-fold synergistic function: protecting the current season's rice, adsorbing residues, promoting degradation, and improving the soil, fundamentally solving the technical problem of existing safeners' inability to address soil residues.

[0073] 2. This invention adds the flotation agent and surface spreader to the kneading system in stages. The flotation agent is added after the basic kneading is completed and kneaded for a short time to ensure uniform dispersion, avoiding structural breakage of low-density materials such as hollow glass microspheres or cork powder due to excessive shearing. This ensures that the overall specific gravity of the particles is controlled at 0.6-0.9, allowing them to float after entering the water. The surface spreader is added in the final stage before granulation and kneaded rapidly to enrich it on the outermost layer of the particles. After entering the water, it quickly diffuses to the surface to form a surface tension gradient, driving the particles to spread automatically. This staged kneading process ensures that the flotation agent is distributed inside the particles to guarantee buoyancy, while the surface spreader is distributed on the particle surface to guarantee spreading performance. Both components perform their respective functions without interfering with each other, overcoming the defects of uneven distribution and mutual functional constraints of components in traditional preparation processes.

[0074] 3. This invention combines the broad-spectrum contact herbicides of cyprodinil, the barnyardgrass-specific efficacy of oxadiazon, and the resistant weed control capabilities of sulfadiazon, achieving control of multiple weeds, including grasses, broadleaf weeds, and sedges, with a single application. Furthermore, the introduction of a fulvic acid-pyridazine complex safener significantly enhances rice's tolerance to the three herbicides, eliminating symptoms such as yellowing and stunting after application. Subsequent crop sowing verification shows that after using the composition of this invention, the germination rate of subsequent wheat or rapeseed crops was not significantly different from the untreated control (relative germination rate ≥94%), indicating that the technical solution of this invention helps reduce the risk of herbicide damage to subsequent crops. This invention achieves a balance between efficient weed control and crop safety, as well as seasonal protection and subsequent crop safety, providing a safe and effective weed control solution for rice-wheat and rice-rapeseed rotation fields. Attached Figure Description

[0075] Figure 1 This is a photograph of the herbicide composition of Example 7 of the present invention;

[0076] Figure 2 This is a diagram showing the automatic dispersion effect of the weed-removing composition in Example 7 of the present invention after being added to water. Detailed Implementation

[0077] The technical solutions of this invention are described below. It should also be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments; those skilled in the art can also use other alternative methods to implement some well-known technologies.

[0078] The hydrolysis conditions are:

[0079] The dried product was dissolved in an ethanol-water mixture, and sodium hydroxide was added. The molar ratio of product to sodium hydroxide was 1:1.3. The mixture was then hydrolyzed at 55°C for 3 hours.

[0080] Example 1: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0081] The herbicidal composition comprises the following components in parts by weight: 0.2 parts of bispyribac-sodium, 10 parts of oxadiazon, 10 parts of bicyclosulfonate, 10 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of hydrogenated castor oil, 15 parts of hollow glass beads, 20 parts of bentonite, and soluble starch to make up to 100 parts.

[0082] The preparation processes for Examples 1-7 are as follows:

[0083] S1. Preparation of composite safety agent:

[0084] S101. Add cyclohexidine, 6-bromo-1-hexanol, and potassium carbonate to dimethylformamide in a weight ratio of 1:1.2-1.5:1-1.5, react at 70-80℃ for 6-10 h, and then extract, dry, hydrolyze, and recrystallize to obtain hydroxylated cyclohexidine.

[0085] S102. Fulvic acid, hydroxyl oxychloride, and 4-dimethylaminopyridine in a mass ratio of 1:0.6:0.1 are dissolved in dimethylformamide. 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is added dropwise in an amount 1.5-2.5 times the mass of fulvic acid. The mixture is stirred at room temperature for 2 hours, then heated to 40°C and reacted for 12-16 hours. After acid precipitation, water washing, alcohol washing, and drying, a composite safer is obtained.

[0086] S2, Ultrafine Grinding:

[0087] The ingredients, including bispyribac-sodium, oxadiazon, bispyribac-sodium, a composite safener, a dispersant, a wetting agent, a binder, and some fillers, are mixed evenly according to the weight ratio described in claim 1, and then fed into an air jet mill for pulverization until the particle size of the solid particles in the powder is less than 20 μm, thus obtaining ultrafine powder.

[0088] S3, Step-by-step kneading and granulation

[0089] S301. Add the ultrafine powder, the remaining filler, and water (10-25% of the total weight of the dry material) into a kneader and knead for 15-30 minutes until uniform.

[0090] S302. Add the flotation agent to the kneader and continue kneading for 5-10 minutes.

[0091] S303. Add the water surface expander to the kneader and knead quickly for 4 minutes. Transfer the kneaded material to the extrusion granulator for granulation to obtain cylindrical wet granules. Place them in a dryer to dry at a temperature of 50-60℃ until the moisture content of the granules is ≤3%.

[0092] S4. Screening:

[0093] The dried granules are graded and sorted to remove oversized lumps and finely crushed particles, resulting in cylindrical granules with a diameter of 1.0-1.5 mm and a length of 3-8 mm, which are the finished floating granule agent.

[0094] Example 2: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0095] The herbicidal composition comprises the following components in parts by weight: 5 parts of bispyribac-sodium, 1 part of oxadiazon, 10 parts of bicyclosulfonate, 10 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of hydrogenated castor oil, 15 parts of hollow glass beads, 20 parts of bentonite, and soluble starch to make up to 100 parts.

[0096] Example 3: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0097] The herbicidal composition comprises the following components in parts by weight: 5 parts of bispyribac-sodium, 10 parts of oxadiazon, 10 parts of bicyclosulfonyl sulfonate, 5 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of hydrogenated castor oil, 15 parts of hollow glass beads, 20 parts of bentonite, and soluble starch to make up to 100 parts.

[0098] Example 4: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0099] The herbicidal composition comprises the following components in parts by weight: 5 parts of bispyribac-sodium, 10 parts of oxadiazon, 10 parts of bicyclosulfonyl sulfonate, 10 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of alkylaryl polyoxyethylene polyoxypropylene ether, 15 parts of hollow glass beads, 20 parts of bentonite, and soluble starch to make up to 100 parts.

[0100] Example 5: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0101] The herbicidal composition comprises the following components in parts by weight: 5 parts of bispyribac-sodium, 10 parts of oxadiazon, 10 parts of bicyclosulfonyl sulfonate, 10 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of hydrogenated castor oil, 15 parts of cork powder, 20 parts of bentonite, and soluble starch to make up to 100 parts.

[0102] Example 6: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0103] The herbicidal composition comprises the following components in parts by weight: 5 parts of bispyribac-sodium, 10 parts of oxadiazon, 10 parts of bicyclosulfonyl sulfonate, 10 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of hydrogenated castor oil, 15 parts of hollow glass beads, and soluble starch to make up to 100 parts.

[0104] Example 7: Preparation of an agricultural ternary compound automatic floating weed control composition:

[0105] The herbicidal composition comprises the following components in parts by weight: 5 parts of bispyribac-sodium, 10 parts of oxadiazon, 10 parts of bicyclosulfonyl sulfonate, 10 parts of compound safener, 3 parts of naphthalene sulfonate, 3 parts of lignin sulfonate, 5 parts of hydroxypropyl methylcellulose, 10 parts of hydrogenated castor oil, 15 parts of hollow glass beads, 20 parts of bentonite, and soluble starch to make up to 100 parts.

[0106] Comparative Example 1:

[0107] Compared with Example 7, no composite safety agent was added in Comparative Example 1, and the amount of soluble starch was increased accordingly to make up to 100 parts. Other components and preparation process (preparation without composite safety agent) were the same as in Example 7.

[0108] Comparative Example 2:

[0109] Compared with Example 7, Comparative Example 2 did not add bispyribac-sodium, and the amount of soluble starch was increased accordingly to make up to 100 parts. Other components and preparation processes were the same as in Example 7.

[0110] Comparative Example 3:

[0111] Compared to Example 7, Comparative Example 3 did not add oxadiazon, and the amount of soluble starch was increased accordingly to make up to 100 parts. All other components and preparation processes were the same as in Example 7.

[0112] Comparative Example 4:

[0113] Compared with Example 7, in Comparative Example 4, soluble starch was replaced with sodium sulfate as filler, that is, sodium sulfate was used to make up to 100 parts. Other components and preparation process were the same as in Example 7.

[0114] Comparative Example 5:

[0115] Compared with Example 7, Comparative Example 5 adopted a conventional process, that is, all components (including water surface expander and flotation agent) were mixed together, air-jet pulverized, and then kneaded and granulated. Other components and dosages were the same as in Example 7.

[0116] Comparative Example 6:

[0117] Compared with Example 7, in Comparative Example 6, the composite safener was replaced with a physical mixture of glyphosate technical and fulvic acid technical. The amount of glyphosate technical was 3.8 parts, the amount of fulvic acid technical was 6.2 parts, and the amount of soluble starch was adjusted accordingly to make up to 100 parts. Other components and preparation process (without the preparation of composite safener) were the same as in Example 7.

[0118] Comparative Example 7:

[0119] Compared with Example 7, Comparative Example 7 did not add bicyclosulfuron, and the amount of soluble starch was increased accordingly to make up to 100 parts. Other components and preparation processes were the same as in Example 7.

[0120] The weight composition of Examples 1-7 and Comparative Examples 1-7 is shown in Table 1 below. The difference between Comparative Examples 1-7 and Example 7 lies in the variable settings, as shown in the data in the table below.

[0121] Table 1. Formulation composition of Examples 1-7 and Comparative Examples 1-7 (unit: parts by weight)

[0122]

[0123] Performance testing:

[0124] 1. The suspension rate determination shall be performed in accordance with GB / T 14825-2023 "Method for Determination of Suspension Rate of Pesticides".

[0125] 2. Disintegration Time Determination: Take 10 intact granules and place them in 250mL beakers containing 200mL of water (25℃). Observe and record the time from the time each granule is placed in the water until it completely disintegrates, and take the average value. Determine the disintegration time under the following four conditions: ① Initial disintegration time, i.e., directly measured after the product is produced and packaged; ② Disintegration time after 54℃ heat storage, measured after storing the sample in a constant temperature chamber at 54℃±2℃ for 14 days according to GB / T 19136-2021 "Test Method for Heat Storage Stability of Pesticides"; ③ Disintegration time after one year of normal storage, measured after storing the product at room temperature (25℃±2℃) for 12 months; ④ Disintegration time after two years of normal storage, measured after storing the product at room temperature (25℃±2℃) for 24 months.

[0126] 3. Follow the relevant sections of GB / T 17980 "Guidelines for Field Efficacy Testing of Pesticides" applicable to herbicides in paddy fields. Select barnyard grass and duckweed as the main targets, and set up water control, herbicide control, and treatment areas for the composition of this invention. Each plot area is 20m². 2 The application was repeated four times. In the field, application was performed by broadcasting in paddy fields or by shallow water application. Ten and twenty days after application, the number of grassy and broadleaf weeds in each treatment area was investigated to calculate the control effect. The calculation formula was: Control efficacy per plant (%) = (Number of weeds in the control area - Number of weeds in the treatment area) / Number of weeds in the control area × 100. If the weeds showed obvious signs of death and significant differences in fresh weight, the control efficacy per plant was determined: Control efficacy per plant (%) = (Fresh weight of weeds in the control area - Fresh weight of weeds in the treatment area) / Fresh weight of weeds in the control area × 100%.

[0127] 4. Floating distance measurement:

[0128] Floating distance measurement: In a cement pool or artificial water tank with a length of 5m, a width of 1m, and a water depth of 3-5cm, 10 particles are scattered in the center of the water surface. After the particles stop moving, the farthest straight-line distance from the scattering point to the final position of each particle on the water surface is recorded, and the average value of 10 particles is taken.

[0129] 5. Safety testing of rice:

[0130] The treatment was conducted in accordance with GB / T 17980 "Guidelines for Field Efficacy Tests of Pesticides" and GB / T 31270.19-2014 "Guidelines for Environmental Safety Evaluation Tests of Chemical Pesticides Part 19: Tests on Effects on Non-Target Plants". Rice seeds were sown in seedling pots after germination, 10 seeds per pot. When the rice seedlings reached the one-leaf-one-heart stage, a water control group, a herbicide-only treatment group, and a treatment group using the composition of this invention were set up. Application was carried out in the field by broadcasting in paddy fields or by shallow water application. Rice plant height was measured 7 and 14 days after application, and symptoms of pesticide damage such as yellowing, stunting, deformity, and death of leaves were observed. The calculation formula is: Plant height inhibition rate (%) = (Control group plant height - Treatment group plant height) / Control group plant height × 100%.

[0131] 6. Safety testing of subsequent crops:

[0132] Apply the composition of this invention at the recommended dosage under potted conditions, using untreated soil as a control. Take topsoil (0-10cm) from each treatment group 30 days after application. Place the soil into nutrient pots (200g per pot), sow wheat or rapeseed seeds (10 seeds per pot), and cultivate in an artificial climate chamber for 7-10 days (temperature 25℃, light 16h / day). Calculate the relative germination rate. The calculation formula is: Relative germination rate (%) = Number of germinated seeds in the treatment group ÷ Number of germinated seeds in the control group × 100.

[0133] The results of the above measurements are shown in Tables 2 and 3 below.

[0134] Table 2 Physical performance test data of the examples and comparative examples

[0135]

[0136] Table 3. Weed control efficacy (per plant control efficacy) and safety data for subsequent crops in the examples and comparative studies.

[0137]

[0138] Figure 1 The image shows a photograph of the finished ternary compound self-floating herbicide granules prepared in Example 7 of this invention. As can be seen from the image, the granules have a regular cylindrical structure with a diameter of approximately 1.0-1.5 mm and a length of approximately 3-8 mm. The granules are intact and uniform in shape, without obvious breakage or adhesion, which meets the morphological requirements of the floating granule product designed in this invention.

[0139] Figure 2 This is a photograph showing the automatic dispersion effect of the floating granules in Example 7 of the present invention after being introduced into water. The granules quickly float to the surface after being introduced into the water and spread evenly under the action of the surface spreader, without agglomeration or sedimentation. This demonstrates the automatic floating and uniform dispersion characteristics achieved by the step-by-step kneading process and the synergistic effect of the surface spreader in this invention, providing a foundation for uniform pesticide application in paddy fields.

[0140] Based on the data in Tables 2 and 3, and considering the variable settings for each formula, the following conclusions can be drawn:

[0141] (1) The covalent linkage of the compound safener is the key to ensuring the safety of rice and subsequent crops:

[0142] Comparing Example 7 with Comparative Example 1, it can be seen that without adding any safener, the rice plant height inhibition rate is as high as 15.8%, and the germination rate of the subsequent wheat crop is only 82%; after adding the compound safener (Example 7), the plant height inhibition rate is reduced to 3.2%, and the germination rate of the subsequent crop is increased to 95%.

[0143] In the compound safener, glyphosate is covalently linked to the fulvic acid skeleton via ester bonds. This ester bond can be gradually hydrolyzed in the paddy field environment (including enzymatic and chemical hydrolysis), and the released glyphosate can be absorbed by rice, helping to improve rice's tolerance to herbicides; the fulvic acid skeleton can be dispersed in the paddy field, adsorbing free herbicide residues through its carboxyl and phenolic hydroxyl groups, thus reducing its bioavailability.

[0144] Comparative Example 6, which used a physical mixture of glyphosate and fulvic acid, resulted in an 88% germination rate and a 9.2% plant height inhibition rate for the subsequent wheat crop. Example 7, using a covalently linked composite safener, achieved a 95% germination rate and a 3.2% plant height inhibition rate for the subsequent wheat crop. The comparison shows that, at the same active ingredient dosage, the covalent linking method helps to further improve the safety of the subsequent crop, but the physical mixing method also exhibits some safener activity. The advantage of covalent linking may be related to its ability to improve the simultaneous release of glyphosate and fulvic acid.

[0145] (2) Contribution analysis of each component in the ternary compound:

[0146] By comparing the herbicidal effects of Example 7 (full formulation) with those of Comparative Example 2 (without bispyribac-sodium), Comparative Example 3 (without oxadiazon), and Comparative Example 7 (without bispyribac-sodium), the contribution of each active component in the compound formulation can be clearly identified.

[0147] Comparative Example 2, without the addition of bispyribac, showed a significant decrease in both grass and broadleaf plant control efficacy (only 70.0% for grass and 72.0% for broadleaf plants after 20 days), indicating that bispyribac is the broad-spectrum basis of the entire compound system, and its absence resulted in a substantial reduction in overall plant control efficacy.

[0148] In Comparative Example 3, without the addition of oxadiazon, the control efficacy against grassy weeds decreased significantly (to only 62.0% after 20 days), while the control efficacy against broadleaf weeds remained basically unchanged, indicating that oxadiazon mainly contributes to the control of grassy weeds.

[0149] In Comparative Example 7, without the addition of bicyclosulfuron, the control efficacy against broadleaf weeds decreased significantly (83.5% after 20 days), while the control efficacy against grasses remained basically unchanged, indicating that bicyclosulfuron mainly contributes to the control of broadleaf weeds.

[0150] Analysis of the three components shows that: bispyribac provides a broad-spectrum basis, oxadiazon mainly targets grasses, and dicyclosulfuron enhances the control efficacy against broadleaf plants. The three components form a complementary weed control spectrum, and none of them can be omitted.

[0151] (3) The step-by-step kneading process is crucial to buoyancy performance and disintegration stability:

[0152] Comparative Example 5, using a conventional process (i.e., crushing all components together and then kneading), showed a floating distance of only 1.2 m and an initial disintegration time extended to 680 s, with further increases in disintegration time after both hot and normal storage. This is because in the conventional process, hollow glass beads are extensively crushed during airflow pulverization, leading to increased particle density and decreased buoyancy; the surface spreader is added too early and mixed into the particle interior, reducing surface enrichment concentration and weakening spreading performance. In contrast, the stepwise kneading process (Example 7), by adding the flotation agent later and the surface spreader last, protects the integrity of the flotation agent and the surface enrichment of the spreader, achieving stable floating performance and controllable disintegration behavior.

[0153] (4) The choice of filler affects the disintegration rate and suspension stability:

[0154] Comparative Example 4 used sodium sulfate instead of soluble starch, which initially shortened the disintegration time to 490 s. However, after heat storage, the disintegration time increased significantly (from 490 s to 520 s), and the suspension rate decreased to 68%. Sodium sulfate is a highly water-soluble inorganic salt that dissolves rapidly in water, forming dissolution channels and accelerating water penetration, leading to faster disintegration. Simultaneously, due to its lack of binding and water-absorbing swelling capacity, microcracks easily form in the particles after heat storage, causing disintegration time drift. Soluble starch, after absorbing water and swelling, generates uniform internal stress, making the disintegration process gentle and controllable, with a higher suspension rate, making it more suitable for this sustained-release system.

[0155] (5) The choice of surface spreader and flotation agent has a differentiated impact on performance:

[0156] Example 4, using alkylaryl polyoxyethylene polyoxypropylene ether as a single agent, exhibited the fastest initial disintegration (500s) and the longest floating distance (2.6m), due to its extremely low dynamic surface tension, which allows for rapid spreading and promotes water penetration. Example 5, using cork powder instead of hollow glass beads, resulted in a slightly shorter floating distance (2.2m) and a longer disintegration time (550s), likely due to the irregular shape and rough surface of the cork powder, which exhibited greater water resistance and slightly increased weight after absorbing water. Example 6, without the addition of bentonite, showed the longest disintegration time (570s), confirming that the water absorption and swelling of bentonite is one of the main driving forces promoting disintegration.

[0157] In summary, this invention, through covalently linked composite safeners, ternary compound weed control systems, stepwise kneading processes, and optimized filler combinations, simultaneously solves four technical problems: seasonal weed control, seasonal herbicide damage, subsequent crop residues, and soil improvement. It achieves a four-in-one technical effect of "weed control + rice protection + residue reduction + soil improvement," demonstrating significant synergistic effects and application value.

[0158] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An agricultural ternary compound automatic floating weeding composition, characterized in that, This composition is a flotation granule agent, comprising the following components in parts by weight: Bismuth subtilis: 0.2-10 parts; Oxadiazon: 1-20 parts; Bicyclosulfuron: 1-20 parts; Compound safety agent: 5-15 parts; Dispersant: 2-10 parts; Wetting agent: 1-10 parts; Adhesive: 1-10 parts; Water surface spreader: 2-20 parts; Flotation agent: 2-30 parts; Filler: 5-50 parts; The composite safener is composed of fulvic acid and hydroxylated oxychloride covalently linked by ester bonds, and its preparation method includes: S1. Add cyclohexidine, 6-bromo-1-hexanol, and potassium carbonate to dimethylformamide in a weight ratio of 1:(1.2-1.5):(1-1.5), react at 70-80℃ for 6-10 h, and then extract, dry, hydrolyze, and recrystallize to obtain hydroxyl-containing cyclohexidine. S2. Fulvic acid, hydroxyl oxychloride, and 4-dimethylaminopyridine are dissolved in dimethylformamide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is added dropwise. The mixture is stirred at room temperature for 2 hours, then heated to 40°C and reacted for 12-16 hours. After acid precipitation, water washing, alcohol washing, and drying, the composite safety agent is obtained.

2. The ternary compound automatic floating weeding composition for agricultural use according to claim 1, characterized in that, The hydrolysis conditions described in S1 are: The dried product was dissolved in an ethanol-water mixture, and sodium hydroxide was added. The molar ratio of product to sodium hydroxide was 1:1.2-1.

5. The product was hydrolyzed at 50-60℃ for 2-4 hours.

3. The ternary compound automatic floating weeding composition for agricultural use according to claim 1, characterized in that, The mass ratio of fulvic acid, hydroxyl oxychloride, and 4-dimethylaminopyridine in S2 is 1:(0.4-0.8):(0.05-0.15), and the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.5-2.5 times the mass of fulvic acid. The fulvic acid is fulvic acid derived from weathered coal, with a number-average molecular weight of 1000-2000 Da and a carboxyl content of 6-8 mmol / g. The acid precipitation uses 5-10wt% dilute hydrochloric acid.

4. The ternary compound automatic floating weeding composition for agricultural use according to claim 1, characterized in that, The disintegration time of the floating granules after entering the water is 8-12 minutes, and the active ingredients and water-soluble additives are completely released or dissolved in the water. The flotation agent controls the overall specific gravity of the floating granules to be 0.6-0.

9.

5. The ternary compound automatic floating weeding composition for agricultural use according to claim 1, characterized in that, The dispersant is selected from one or more of polycarboxylate, naphthalene sulfonate, and lignin sulfonate; The wetting agent is selected from one or more of alkyl sulfonates and alkyl sulfates; The adhesive is selected from one or more of carboxymethyl cellulose, hydroxypropyl methyl cellulose, and sodium carboxymethyl starch; The water surface spreader is selected from one or more of hydrogenated castor oil, styrylphenol polyoxyethylene ether, alkyl aryl polyoxyethylene polyoxypropylene ether, alkyl aryl methyl ether resin polyoxyethylene ether, and α-methyl benzyl polyoxyethylene ether. The flotation agent is selected from one or more of hollow glass microspheres, cork powder, and porous starch; The true density of the hollow glass microspheres is 0.2-0.6 g / cm³. 3 The particle size is 30-100μm, while the particle size of cork powder is 100-300 mesh, and the density of porous starch is 0.4-0.8g / cm³. 3 The particle size is 10-200μm; The filler is selected from one or more of bentonite, soluble starch, diatomaceous earth, and potassium chloride.

6. The method for preparing an agricultural ternary compound automatic floating weed control composition according to claim 1, characterized in that... Includes the following steps: T1, Ultrafine Grinding: The ingredients, including bispyribac-sodium, oxadiazon, bispyribac-sodium, a composite safener, a dispersant, a wetting agent, a binder, and some fillers, are mixed evenly according to the weight ratio described in claim 1, and then fed into an air jet mill for pulverization until the particle size of the solid particles in the powder is less than 20 μm, thus obtaining ultrafine powder. T2, Stepwise kneading and granulation T201. Add the ultrafine powder, the remaining filler, and water (10-25% of the total weight of the dry materials) into a kneader and knead for 15-30 minutes until uniform. T202. Add the flotation agent to the kneader and continue kneading for 5-10 minutes. T203. Add the water surface expander to the kneader and knead quickly for 3-5 minutes. Transfer the kneaded material to an extrusion granulator for granulation to obtain cylindrical wet granules. Place the granules in a dryer and dry at a temperature of 50-60℃ until the moisture content of the granules is ≤3%. T3, Screening: The dried granules are graded and sorted to remove oversized lumps and finely crushed particles, resulting in cylindrical granules with a diameter of 1.0-1.5 mm and a length of 3-8 mm, which are the finished floating granule agent.

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