JP2013163625A - Method for preventing ammonium sulfate from caking, method for producing ammonium sulfate-mixed fertilizer, and ammonium sulfate-mixed fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preventing ammonium sulfate from caking, the method obtaining a sufficient caking-preventing effect for a component of fertilizer and having no bad influence on the environment; and to provide an ammonium sulfate-mixed fertilizer.SOLUTION: A method for preventing ammonium sulfate from caking includes at least a process in which particulate ammonium sulfate for fertilizer is mixed with a solution whose solute is a saccharide. In the method, the solvent in the solution evaporates to coat the surface of the ammonium sulfate with the saccharide. The saccharide is trehalose, and the amount of the saccharide is at least 0.1 wt.%, in particular, at least 0.5 wt.% to the amount of the ammonium sulfate. The solvent is water or an organic solvent, and the evaporation of the solvent by heating is acceptable. An ammonium sulfate-mixed fertilizer is produced by using the method for preventing ammonium sulfate from caking. At least ammonium phosphate and potassium chloride are blended as other components of the ammonium sulfate-mixed fertilizer.

Description

  TECHNICAL FIELD The present invention relates to a method for preventing caking of ammonium sulfate blended in a fertilizer, a method for producing a fertilizer blended with ammonium sulfate subjected to the caking prevention treatment, and an ammonium sulfate blended fertilizer produced by the manufacturing method.

  Ammonium sulfate is generally used as a chemical fertilizer component. Ammonium sulfate blended with fertilizers may solidify during storage of the fertilizers. This consolidation is thought to be due to cross-linking between the particles due to recrystallization occurring on the surface of the ammonia sulfate particles due to the absorption and release of moisture.

  The degree of moisture absorption and release varies depending on the storage conditions, but compared to the case of ammonia sulfate alone, multi-component ammonia sulfate-containing fertilizer containing other chemical substances (ammonia phosphate, potassium chloride, etc.) in ammonia sulfate. Tend to be bigger. As a result, the ammonium sulfate-containing fertilizer is more easily consolidated than ammonia sulfate alone.

  If the fertilizer is consolidated during storage, workability deteriorates when fertilizing, so it is necessary to take measures to prevent consolidation.

  Conventionally, as a method for preventing caking of an ammonium sulfate-containing fertilizer, a process of coating ammonia sulfate particles with various substances is known. As the coating substance, natural inorganic fine powders such as talc and diatomaceous earth, and oily substances such as paraffin wax are used. The purpose of the coating material is to keep the particles apart and not in direct contact. It is also known to mix with a surfactant such as a higher alcohol sulfate ester salt (Patent Document 1, etc.). The purpose of the surfactant is to make it hard to solidify by changing the characteristics of the crystal surface of the particles.

  Here, although it is a completely different technical field, a method of coating the crystal surface of salt with trehalose is known as a method for preventing the caking of salt (Patent Document 2). In the biochemical field, it is known to mix oligosaccharides such as trehalose as water / humectants for enzymes, cells, proteins and the like (Patent Document 3).

Japanese Unexamined Patent Publication No. 64-51388 JP 2000-233923 A JP 2005-52044 A

The conventional fertilizer consolidation prevention method described above has the following problems.
-Inorganic fine powders such as talc and diatomaceous earth require a relatively large amount to be added in order to obtain a sufficient anti-caking effect. If the amount added is too large, the proportion of fertilizer components decreases.
・ For the anti-caking material of fine powder, the residual fine powder that did not adhere to the particles of ammonium sulfate causes dust generation and deteriorates the working environment.
-Fertilizers composed of ammonia sulfate with a surfactant added may not provide a sufficient anti-caking effect.

  In view of the above-described situation, the present invention provides a method for preventing the consolidation of ammonia sulfate, which provides a sufficient anti-caking effect when ammonia sulfate is used as a fertilizer component and does not adversely affect the environment. For the purpose. Furthermore, it aims at providing the method and the fertilizer which manufacture the fertilizer which mix | blended the ammonium sulfate processed with such a caking prevention method.

In order to achieve the above object, the present invention provides the following configurations.
The method for preventing caking of ammonium sulfate according to the present invention has at least a step of mixing particulate ammonium sulfate for fertilizer and a solution containing oligosaccharide as a solute, and the saccharide is evaporated by evaporation of the solvent in the solution. Covers the surface of the ammonium sulfate. In particular, the oligosaccharide is preferably trehalose. Moreover, it is preferable that the amount of trehalose contained in the solution is 0.1 wt% or more with respect to the amount of the ammonium sulfate. Furthermore, it is preferable that the amount of trehalose contained in the solution is 0.5 wt% or more with respect to the amount of ammonia sulfate. The solvent is preferably water or an organic solvent. Furthermore, it is preferable to evaporate the solvent by heating.
The method for producing an ammonium sulfate-containing fertilizer according to the present invention comprises a step of anti-caking treatment of particulate ammonium sulfate using the above-described method of preventing ammonium sulfate consolidation, and the above-mentioned ammonia sulfate subjected to anti-caking treatment. And a step of preparing a fertilizer.
The fertilizer containing ammonia sulfate according to the present invention is characterized by blending particulate ammonium sulfate that has been subjected to anti-caking treatment using the above-described method for preventing caking of ammonium sulfate.
In addition, it is suitable to mix | blend at least ammonium phosphate and potassium chloride as another component of a fertilizer.

  The method for preventing caking of ammonia sulfate according to the present invention includes at least a step of mixing particulate ammonium sulfate for fertilizer with a saccharide solution. Thereafter, the solvent contained in the solution evaporates, whereby the surface of the ammonium sulfate is covered with a saccharide film. This suppresses the absorption and release of moisture in the ammonium sulfate particles. As a result, the anti-caking effect of ammonia sulfate can be obtained. Furthermore, an ammonium sulfate-containing fertilizer in which ammonia sulfate subjected to such an anti-caking treatment is added can be produced. Similarly, in the manufactured fertilizer, an anti-caking effect of ammonia sulfate can be obtained. In particular, it has been found that when trehalose is used as the saccharide, a remarkable effect can be obtained.

  In addition, although the anti-caking effect and the anti-drying effect of oligosaccharides were known in different fields such as Patent Documents 2 and 3, the fields of pure salt and biochemistry are quite different from the fertilizer field to which the present invention belongs. Therefore, the target substance for preventing caking is completely different from the present invention. Therefore, to obtain an anti-caking effect with saccharides in ammonia sulfate, which is a fertilizer component, should be an unpredictable effect, not just a diversion from the different fields.

Hereinafter, embodiments of the present invention will be described with reference to examples of the present invention.
Ammonium sulfate to which the present invention is applied is in the form of particles blended as a fertilizer. As particulate ammonium sulfate, there are a powdered ammonia sulfate solidified by compression or the like and granulated, and a particulate crystal. The granulation method is not limited to a specific method. The particles produced by any known production method usually have an average particle size of 0.5 mm to 5 mm. The anti-caking method according to the present invention gives good results with such particulate ammonia sulfate.

  The basic principle of the present invention is that the surface of particles of ammonia sulfate is coated with saccharides, and the release and absorption of moisture from the particles are suppressed by utilizing the water retention and moisture retention properties of the saccharides, thereby solidifying the particles. This is what realizes prevention. For this reason, in this invention, it has at least the process of mixing the solution which makes particulate ammonium sulfate for fertilizers, and saccharides solute. After mixing of the ammonium sulfate and the solution, the solvent in the solution evaporates to form a saccharide film on the surface of the ammonium sulfate particles. That is, the ammonium sulfate particles are coated with saccharides.

  As the saccharide, oligosaccharide is preferable. Among oligosaccharides, trehalose has the best water retention and is suitable, but raffinose or maltose may also be used. Even if other known oligosaccharides are used, a certain degree of effect can be obtained.

  As the solvent, an organic solvent such as water or ethanol which is easily evaporated is suitable. For example, the transpiration may be naturally evaporated by being left at room temperature. Or you may heat and evaporate with a dryer etc. When the solvent is ethanol, or when the solvent is water, a small amount is preferable because heating is not necessary for transpiration. The reason why the saccharide is used as a solution is to mix ammonia sulfate and saccharide evenly. Therefore, if the amount of the solvent is large, the viscosity of the solution becomes low and it is easy to mix, but on the other hand, it takes time and heat to evaporate the solvent. Set the volume or concentration of the solution.

Next, an embodiment of a method for preventing caking of ammonia sulfate according to the present invention will be described. The present embodiment includes the following first to third steps.
First step: An aqueous solution of sugars is prepared using water as a solvent. The concentration of the aqueous solution is preferably a water-rich and low-viscosity solution that is uniformly mixed with ammonia sulfate in the second step described later, while water is used to reduce the burden of transpiration of water in the third step described later. Since the smaller one is preferable, it is set appropriately.

  Second step: The aqueous saccharide solution prepared in the first step is mixed with particulate ammonia sulfate. Mix so that the surface of each particle is uniformly and evenly wetted with an aqueous solution of sugars. For this purpose, the aqueous solution may be sprayed onto ammonia sulfate, or the ammonia sulfate mixed with the aqueous solution may be stirred. The amount of the aqueous solution to be mixed is set so that the amount of saccharide contained in the aqueous solution to be mixed becomes a predetermined ratio or more with respect to the amount of ammonia sulfate. The amount of saccharide contained in the aqueous solution to be mixed depends on the concentration of the aqueous solution and the amount of the aqueous solution.

  Third step: Only water originally contained in the aqueous solution is evaporated from the mixture obtained in the second step. As a general method, water can be efficiently removed by heating and drying the mixture. At this time, if there is much water, it will take time and cost to dry.

  The surface of the ammonium sulfate particles obtained by the above first to third steps is covered with a saccharide film. In order for each particle to be almost entirely covered with the film, the saccharides should be 0.1 wt% or more with respect to the weight of the ammonia sulfate (the saccharide is 0.1 with respect to the ammonia sulfate 100 in weight ratio). . Suitably, saccharides are 0.5 wt% or more with respect to the weight of ammonia sulfate (0.5 saccharides with respect to ammonia sulfate 100 in weight ratio). This is supported by the test results of consolidation strength. In addition, the weight ratio of this saccharide | sugar and ammonium sulfate has nothing to do with the kind of solvent fundamentally (because a solvent evaporates).

  As another example, when ethanol is used as a solvent, ethanol is used as the solvent in the first step in the above example. The second step in the above embodiment is common. In addition, the 3rd process in the said Example becomes unnecessary. This is because ethanol evaporates simply by leaving the mixture obtained in the second step. In this case, since heating equipment and heat energy are unnecessary, the cost is low.

  As described above, ammonia sulfate that has been subjected to anti-caking treatment may be used alone as an ammonium sulfate-containing fertilizer, or it may be combined with one or more other chemical substances to produce an ammonium sulfate-containing fertilizer consisting of multiple components. May be. In general, an ammonium sulfate-containing fertilizer containing at least ammonia phosphate and potassium chloride as other components is often used.

Hereinafter, specific examples of the embodiment of the present invention described above will be shown.
<Preparation of sample>
First step: First, a 50% aqueous solution of trehalose was prepared. About 100 g of trehalose dissolves at 100 ° C. with respect to 100 g of water. Since the solubility of trehalose depends on the temperature, water is dissolved by heating as necessary.
Second step: Next, the trehalose aqueous solution prepared in the first step was added in the following three ratios with respect to ammonia sulfate and mixed thoroughly.
[Example 1] 100 g of ammonia sulfate and 1 g of an aqueous trehalose solution
(Trehalose aqueous solution is 1.0 wt% with respect to ammonia sulfate)
[Example 2] 100 g of ammonia sulfate and 2 g of an aqueous trehalose solution
(Trehalose aqueous solution is 2.0wt% with respect to ammonia sulfate)
[Example 3] 100 g of ammonia sulfate and 4 g of an aqueous trehalose solution
(Trehalose aqueous solution is 4.0 wt% with respect to ammonia sulfate)
Third step: Next, the mixture of the trehalose aqueous solution and ammonia sulfate mixed in the second step was dried using a dryer.

<Consolidation strength test>
[Example 1] [Example 2] The three types of fertilizer blended with the dried product of [Example 3] obtained above and ammonia sulfate alone without adding a trehalose aqueous solution [Comparative Example] were converted into ammonia phosphate. And the solidification strength test was done with respect to the fertilizer mix | blended with potassium chloride.

  The blending ratio of the fertilizer was ammonia sulfate: ammonium phosphate: potassium chloride = 1: 1: 1. The consolidation strength is a value (crushing strength) representing the pressure required to destroy the consolidated portion when the fertilizer is consolidated.

The method of the consolidation strength test is as follows.
(I) Put 150 g of the sample in a cylinder divided into two cylinders with a diameter of 54 mm.
(Ii) Plug the cylinder in (i).
(Iii) Place a 20 kg weight from above the stopper.
(Iv) Cover (iii) with a plastic bag and leave it in an environment where a cycle of 8 hours at 50 ° C. and 16 hours at 0 ° C. is repeated for 7 days.
(V) If the sample in the cylinder was consolidated, the crushing strength was measured using a force gauge, and this was used as the consolidated strength.

<Test results>
The test results are as shown in Table 1.

  In each example, it was confirmed that an anti-caking effect was obtained as compared with the comparative example.

Claims (10)

  It has at least a step of mixing a particulate ammonium sulfate for fertilizer and a solution containing oligosaccharide as a solute, and the saccharide covers the surface of the ammonium sulfate by evaporating the solvent in the solution. A method for preventing the consolidation of ammonia sulfate.   The method according to claim 1, wherein the oligosaccharide is trehalose.   The method for preventing consolidation of ammonia sulfate according to claim 2, wherein the amount of trehalose contained in the solution is 0.1 wt% or more with respect to the amount of ammonia sulfate.   The method for preventing consolidation of ammonia sulfate according to claim 3, wherein the amount of trehalose contained in the solution is 0.5 wt% or more with respect to the amount of ammonia sulfate.   The method for preventing consolidation of ammonia sulfate according to any one of claims 1 to 4, wherein the solvent is water or an organic solvent.   The method for preventing consolidation of ammonia sulfate according to any one of claims 1 to 5, wherein the solvent is evaporated by heating. In the method of manufacturing a fertilizer blended with particulate ammonium sulfate,
A step of anti-caking treatment of particulate ammonium sulfate using the method of preventing caking of ammonium sulfate according to any one of claims 1 to 6;
And a step of preparing a fertilizer by blending the above-mentioned anti-caking treatment ammonium sulfate, and a method for producing an ammonium sulfate-containing fertilizer.   The method for producing an ammonium sulfate-containing fertilizer according to claim 7, wherein at least ammonium phosphate and potassium chloride are added as components other than the ammonia sulfate. In fertilizers containing particulate ammonium sulfate,
A fertilizer containing ammonium sulfate, which is mixed with particulate ammonium sulfate that has been subjected to anti-caking treatment using the method for preventing caking of ammonia sulfate according to any one of claims 1 to 6.   The fertilizer containing ammonia sulfate according to claim 9, wherein at least ammonium phosphate and potassium chloride are blended as components other than the ammonia sulfate.