阅读说明：本技术 一种包膜硝酸铵钙肥料及其制备方法 (Coated calcium ammonium nitrate fertilizer and preparation method thereof ) 是由 石称华 钱志红 于 2019-10-31 设计创作，主要内容包括：本发明技术方案公开了一种包膜硝酸铵钙肥料的制备方法,包括如下步骤：以硝酸铵钙作为肥芯,在30℃～40℃下,将硝酸铵钙预热0.5h～1h；(2)将六水合硝酸镁和三乙烯二胺的乙醇溶液作为表面处理液,涂布于预热后的肥芯表面,并搅拌3min～5min；(3)加入包膜液,转动7min～10min,冷取、出料。上述制备方法中加入了适量的三乙烯二胺,可以使得聚氨酯的合成过程所需能量大幅度降低,从而将聚氨酯的合成温度降低至40℃以下,甚至可以在室温下进行合成,一方面有效避免了聚氨酯合成时,温度超过硝酸铵钙颗粒的熔程,另一方面制备过程所需温度较低,降低了能源消耗。(The technical scheme of the invention discloses a preparation method of a coated calcium ammonium nitrate fertilizer, which comprises the following steps: preheating calcium ammonium nitrate as a fertilizer core for 0.5 to 1 hour at the temperature of between 30 and 40 ℃; (2) coating the ethanol solution of magnesium nitrate hexahydrate and triethylene diamine on the surface of the preheated fertilizer core as a surface treatment solution, and stirring for 3-5 min; (3) adding the coating liquid, rotating for 7-10 min, cold taking and discharging. The proper amount of triethylene diamine is added in the preparation method, so that the energy required in the synthesis process of the polyurethane can be greatly reduced, the synthesis temperature of the polyurethane is reduced to be below 40 ℃, and the polyurethane can be synthesized even at room temperature, so that the temperature exceeding the melting range of calcium ammonium nitrate particles during the synthesis of the polyurethane is effectively avoided, the temperature required in the preparation process is lower, and the energy consumption is reduced.)

1. The preparation method of the coated calcium ammonium nitrate fertilizer is characterized by comprising the following steps:

(1) preheating the fertilizer core for 0.5 to 1 hour at the temperature of between 30 and 40 ℃ by taking calcium ammonium nitrate particles as the fertilizer core;

(2) coating the ethanol solution of magnesium nitrate hexahydrate and triethylene diamine on the surface of the preheated fertilizer core as a surface treatment solution, and stirring for 3-5 min;

(3) adding a coating liquid, rotating for 7-10 min, cooling, taking out and discharging, wherein the coating liquid comprises polymethylene polyphenyl isocyanate, soybean oil and dibutyl phthalate, and the percentage of each component in the total mass of the calcium ammonium nitrate particles is respectively as follows: 0.8-1.0%, 0.6-0.8% and 0.08-0.12%.

2. The method of producing the coated calcium ammonium nitrate fertilizer of claim 1, wherein the coating rate of the calcium ammonium nitrate granules is 1% to 4%.

3. The method of producing the coated calcium ammonium nitrate fertilizer of claim 2, wherein the coating rate of the calcium ammonium nitrate granules is 2% to 3%.

4. The method of producing the coated calcium ammonium nitrate fertilizer as claimed in claim 1, wherein the mass of the surface treatment liquid is 0.4 to 0.8% of the total mass of the calcium ammonium nitrate granules.

5. The method of producing the coated calcium ammonium nitrate fertilizer as claimed in claim 1, wherein the surface treatment liquid is 0.6 to 0.7% by mass of the total mass of the calcium ammonium nitrate granules.

6. The method of preparing the coated calcium ammonium nitrate fertilizer of claim 1, wherein the triethylene diamine is present in an amount of 0.3% to 0.6% of the coating solution on a dry basis.

7. The method of preparing the coated calcium ammonium nitrate fertilizer of claim 1, wherein the mass ratio of the magnesium nitrate hexahydrate to the triethylenediamine is (5-9): 1.

8. the method of producing the coated calcium ammonium nitrate fertilizer of claim 1, wherein the solvent of the surface treatment liquid is absolute ethanol.

9. A coated calcium ammonium nitrate fertilizer, characterized in that it is obtained by the production method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of fertilizer manufacturing, in particular to a coated calcium ammonium nitrate fertilizer and a preparation method thereof.

Background

The slow-release fertilizer mainly takes a traditional fertilizer as a core fertilizer, and a biodegradable organic coating agent is coated on the outer layer. Few controlled-release calcium ammonium nitrate products, including those that are currently on the market, are available, particularly polyurethane coated calcium ammonium nitrate products. First, calcium ammonium nitrate is very hygroscopic and needs to be dried during granulation and coating, and thus the surface of the fertilizer is not smooth, and thus the adhesion of the coating material is reduced and coating cannot be performed. Secondly, the thermal stability of calcium ammonium nitrate is poor, the hardness of the calcium ammonium nitrate is reduced in the coating process, so that the coating material cannot be uniformly distributed on the surface of fertilizer particles, and the coating effect is extremely poor.

Disclosure of Invention

The technical problem to be solved by the technical scheme of the invention is to provide a preparation method of the coated calcium ammonium nitrate fertilizer with simple steps and good coating effect.

In order to solve the technical problems, the technical scheme of the invention provides a preparation method of a coated calcium ammonium nitrate fertilizer, which comprises the following steps:

(1) preheating the fertilizer core for 0.5 to 1 hour at the temperature of between 30 and 40 ℃ by taking calcium ammonium nitrate particles as the fertilizer core;

(2) coating the ethanol solution of magnesium nitrate hexahydrate and triethylene diamine on the surface of the preheated fertilizer core as a surface treatment solution, and stirring for 3-5 min;

(3) adding a coating liquid, rotating for 7-10 min, cooling, taking out and discharging, wherein the coating liquid comprises polymethylene polyphenyl isocyanate, soybean oil and dibutyl phthalate, and the percentage of each component in the total mass of the calcium ammonium nitrate particles is respectively as follows: 0.8-1.0%, 0.6-0.8% and 0.08-0.12%.

Preferably, the coating rate of the calcium ammonium nitrate granules is 1-4%.

Further preferably, the coating rate of the calcium ammonium nitrate granules is 2% -3%.

Preferably, the mass of the surface treatment liquid is 0.4-0.8% of the total mass of the calcium ammonium nitrate granules.

Further preferably, the mass of the surface treatment liquid is 0.6-0.7% of the total mass of the calcium ammonium nitrate granules.

Preferably, the triethylene diamine accounts for 0.3% -0.6% of the coating liquid on a dry basis.

Preferably, the mass ratio of the magnesium nitrate hexahydrate to the triethylene diamine is (5-9): 1.

preferably, the solvent of the ethanol solution of magnesium nitrate hexahydrate and triethylene diamine is absolute ethanol.

On the other hand, the technical scheme of the invention also provides a coated calcium ammonium nitrate fertilizer which is prepared by the preparation method.

Compared with the prior art, the preparation method of the coated calcium ammonium nitrate fertilizer has the following advantages: the ethanol solution of magnesium nitrate hexahydrate and triethylene diamine is used as the fertilizer surface treatment solution, and the surface treatment solution is a non-aqueous system, so that on one hand, compared with an aqueous system, the energy consumption is greatly reduced during drying, and the reduction of the particle strength is avoided. On the other hand, the calcium ammonium nitrate is easily decomposed into ammonia gas, water and carbon dioxide under the heat capacity, so that the content of effective nitrogen is reduced, the heat stability of the calcium ammonium nitrate can be improved by adding magnesium nitrate hexahydrate, and in addition, magnesium is one of nutrient substances required by the growth and development of plants. Particularly, the proper amount of triethylene diamine is added, so that the energy required in the synthesis process of the polyurethane can be greatly reduced, the synthesis temperature of the polyurethane is reduced to be below 40 ℃, and the polyurethane can be synthesized even at room temperature, so that the temperature exceeding the melting range of calcium ammonium nitrate particles during the synthesis of the polyurethane is effectively avoided, the temperature required in the preparation process is low, the energy consumption is reduced, and the heating step before the synthesis of the polyurethane is saved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.