CN-122010639-A - Special coated high-tower compound fertilizer for herbaceous flowers and preparation method thereof

Abstract

The invention provides a special coated high-tower compound fertilizer for herbaceous flowers and a preparation method thereof, belongs to the technical field of coated compound fertilizers, and solves the problems of poor binding force of a coated high-tower compound fertilizer film core and poor sustained and controlled release effect. The preparation method comprises the steps of (a) preheating high-tower compound fertilizer particles, (b) spraying urea aqueous solution on the surfaces of the preheated high-tower compound fertilizer particles for pretreatment, (c) spraying isocyanate on the surfaces of the pretreated high-tower compound fertilizer particles for coupling reaction, and (d) spraying polyol solution containing tannic acid chelate and a curing agent on the surfaces of the high-tower compound fertilizer particles after the coupling reaction at the same time for solvent-free in-situ curing reaction to form the tannic acid chelate modified bio-based polyurethane film layer. The core film of the coated high-tower compound fertilizer prepared by the method has good binding force, and can achieve the aim of synchronously and controllably releasing various nutrients.

Inventors

• LI WENYI
• DING XI
• WEI YAFEN
• GU YADONG
• ZHANG HUA
• ZHANG XIXI
• CAO JIXIN
• ZHU JIANGANG
• PENG YUXIN
• ZHAO SHIWEI
• ZHAO GUOLONG
• CAO HAI
• LIU CHENXU

Assignees

• 北京市园林绿化科学研究院
• 北京富特来复合肥料有限公司

Dates

Publication Date

20260512

Application Date

20260130

Claims (10)

1. 1. The preparation method of the special coated high-tower compound fertilizer for the herbaceous flowers is characterized by comprising the following steps of: Preheating high-tower compound fertilizer particles; spraying urea aqueous solution on the surfaces of preheated high-tower compound fertilizer particles for pretreatment; spraying isocyanate on the surfaces of the pretreated high-tower compound fertilizer particles to perform coupling reaction; and (d) spraying a polyol solution containing the tannic acid chelate and a curing agent on the surfaces of the high-tower compound fertilizer particles after the coupling reaction at the same time, and performing solvent-free in-situ curing reaction to form the tannic acid chelate modified bio-based polyurethane film.
2. 2. The method for preparing a coated high tower compound fertilizer dedicated to herbaceous flowers according to claim 1, wherein in the step (a), the preheating temperature is 50-60 ℃.
3. 3. The method for preparing the coated high-tower compound fertilizer special for herbaceous flowers, which is characterized in that in the step (b), the mass concentration of urea in the urea aqueous solution is 10-30%, and the mass of the urea aqueous solution accounts for 0.5-2% of the total mass of the high-tower compound fertilizer particles.
4. 4. The method for preparing a coated high tower compound fertilizer special for herbaceous flowers according to claim 1 or 3, wherein in the step (b), the urea aqueous solution further contains an inhibitor, and the inhibitor is a urease inhibitor and/or a nitrification inhibitor.
5. 5. The method for preparing the coated high-tower compound fertilizer special for herbaceous flowers according to claim 4, wherein the mass concentration of the inhibitor in the urea aqueous solution is 1.5-5%.
6. 6. The method for preparing a coated high-tower compound fertilizer special for herbaceous flowers according to claim 1, wherein in the step (c), the isocyanate is used in an amount such that the mass of the isocyanate accounts for 0.1-0.5% of the total mass of the high-tower compound fertilizer particles.
7. 7. The method for preparing a coated high tower compound fertilizer special for herbaceous flowers according to claim 1 or 6, wherein in the step (C), the coupling reaction is carried out at a temperature of 50-60 ℃ for 2-5min.
8. 8. The method for preparing the coated high-tower compound fertilizer special for herbaceous flowers, as claimed in claim 1, wherein in the step (d), the method for preparing the polyol solution containing tannic acid chelate comprises the steps of dissolving tannic acid and metal ion salt in bio-based polyol, and stirring.
9. 9. The method for preparing the coated high-tower compound fertilizer special for herbaceous flowers according to claim 8, wherein the molar ratio of tannic acid to metal ions in the metal ion salt is 1:1-1:5, and the mass of tannic acid is 1-5% of the mass of bio-based polyol.
10. 10. The coated high-tower compound fertilizer special for herbaceous flowers is characterized in that the coated high-tower compound fertilizer special for herbaceous flowers is prepared by the preparation method of any one of claims 1 to 9.

Description

Special coated high-tower compound fertilizer for herbaceous flowers and preparation method thereof Technical Field The invention relates to the technical field of coated compound fertilizers, in particular to a special coated high-tower compound fertilizer for herbaceous flowers and a preparation method thereof. Background The preparation method of the coated nitrogen-phosphorus-potassium compound fertilizer mainly takes coated urea as a main material and mainly comprises the following steps: (1) Because the raw materials are non-uniform in physical and chemical properties, the membrane material is easy to be absorbed by the core compound fertilizer particles, and the adhesiveness of the membrane material on the compound fertilizer particles is poor, so that the core membrane is easy to separate; (2) The coating difficulty and thickness of the coated compound fertilizer are larger than those of the coated urea, especially the high tower compound fertilizer particles are coated, the compound fertilizer adopts a melt vertical spray forming technology, high-temperature molten nitrogen-phosphorus-potassium mixed slurry is sprayed from the top of a hundred-meter high tower, heat exchange solidification granulation is carried out with cold air in the free falling process, the internal gas escapes due to the volume shrinkage effect when the melt is cooled, through holes with the diameter of about 0.1-0.3mm are formed on the surface, and uniform film layers are difficult to form on the surface of the holes when the holes are coated at the opening of the particle surface, so that the stable controlled release effect is achieved; (3) Because of the nutrient dissolution and release differences of the compound fertilizer particles, challenges for accurate fertilization of crops are increased. Along with the increasing demand of the coated compound fertilizer with good sustained and controlled release effect on crops, the problems that the nutrients are difficult to accurately release and control after the coated high-tower compound fertilizer is prepared and the nutrients are difficult to match with the fertilizer of the crops are urgently solved due to the adhesiveness of the film and the through holes on the surfaces of the particles of the high-tower compound fertilizer. Disclosure of Invention The invention aims to solve the technical problem of providing the special coated high-tower compound fertilizer for the herbaceous flowers and the preparation method thereof, which can fundamentally solve the core-film combination problem of the coated high-tower compound fertilizer and achieve the aim of synchronously and controllably releasing various nutrients. In order to solve the technical problems, the technical scheme of the invention is as follows: in a first aspect, the invention provides a preparation method of a special coated high-tower compound fertilizer for herbaceous flowers, which comprises the following steps: Preheating high-tower compound fertilizer particles; spraying urea aqueous solution on the surfaces of preheated high-tower compound fertilizer particles for pretreatment; spraying isocyanate on the surfaces of the pretreated high-tower compound fertilizer particles to perform coupling reaction; and (d) spraying a polyol solution containing the tannic acid chelate and a curing agent on the surfaces of the high-tower compound fertilizer particles after the coupling reaction at the same time, and performing solvent-free in-situ curing reaction to form the tannic acid chelate modified bio-based polyurethane film. Optionally, in step (a), the preheating is at a temperature of 50-60 ℃. Optionally, in the step (b), the mass concentration of urea in the urea aqueous solution is 10-30%, and the use amount of the urea aqueous solution is such that the mass of urea accounts for 0.5-2% of the total mass of the high-tower compound fertilizer granules. Optionally, in step (b), the urea aqueous solution further contains an inhibitor, wherein the inhibitor is a urease inhibitor and/or a nitrification inhibitor. Optionally, the mass concentration of the inhibitor in the urea aqueous solution is 1.5-5%. Optionally, in the step (c), the isocyanate is used in an amount such that the mass of the isocyanate accounts for 0.1 to 0.5% of the total mass of the high tower compound fertilizer granules. Optionally, in step (C), the temperature of the coupling reaction is 50-60 ℃ and the time is 2-5min. Optionally, in the step (d), the preparation method of the polyol solution containing the tannic acid chelate complex comprises the steps of dissolving tannic acid and metal ion salt in bio-based polyol and stirring. Optionally, the molar ratio of the tannic acid to the metal ions in the metal ion salt is 1:1-1:5, and the mass of the tannic acid is 1-5% of the mass of the bio-based polyol. In a second aspect, the invention provides a special coated high-tower compound fertilizer for herbaceous flowers, which is prepared by the p