JP2005104766A - Method of manufacturing nitrolime-based granular fertilizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing nitrolime-based granular fertilizer by which a raw material remaining in a pipe line or a hopper is reduced, a preheating time is shortened and the quantity of a urea binder to be used is decreased. <P>SOLUTION: In the manufacture of the granulated fertilizer by mixing urea and a lubricant with a fertilizer containing nitrolime and extruding the mixture, the quantity of the lubricant to be used is 0.4-2.0 pts.mass per 100 pts.mass in total of the fertilizer containing nitrolime, urea and the lubricant, and the lubricant uses both one or more kinds of fatty acids selected from lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid and the salts of the fatty acid and one or more kinds of fatty acid esters selected from glyceryl fatty acid ester, succinic acid fatty acid ester, sucrose fatty acid ester and sorbitan fatty acid ester. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a method for producing a lime nitrogen granular fertilizer.

To granulate lime nitrogen alone or fertilizer containing lime nitrogen in which this base material is combined with fertilizer components such as molten phosphorous fertilizer, calcined phosphorous fertilizer, lime superphosphate, potassium chloride, potassium sulfate, etc. From the above, a pressure forming method using urea as a binder is known. However, a large amount of energy is required for preheating the granulated raw material and pressure forming. Therefore, in order to solve this problem and to suppress granulation of the granulated product, at least one lubricant selected from the group consisting of hydrogenated soybean oil, stearyl alcohol, sodium oleate, natural paraffin and pitch is granulated. An extrusion method using 0.2 to 5 parts by mass per 100 parts by mass of the raw material has been proposed (Patent Document 1).
Japanese Patent Laid-Open No. 10-1381

However, in these lubricants, the flow action of the granulation raw material varies greatly depending on the type, and when a large flow action is used, clogging in the pipe and hopper is reduced, but the preheating step However, there is a problem that the stirring efficiency by the stirring blades is lowered and it takes time to raise the temperature to the target temperature, and this reverse phenomenon occurs when a thing having a small fluidity is used. For this reason, there are few raw materials remaining in the pipes and hoppers, and the temperature increase during the preliminary heating cannot be completed in a short time. Furthermore, since a relatively large amount of urea was required to produce a granulated fertilizer having desired grain hardness and particle size using these lubricants, the fertilizer effect and agricultural chemical effect of lime nitrogen were impaired.

  In view of the above, the object of the present invention is to reduce the amount of raw material in pipes and hoppers, reduce the preheating time, and expect the effect of reducing the amount of urea binder used. It is to provide a manufacturing method.

That is, the present invention mixes urea and a lubricant with a fertilizer containing lime nitrogen, and when the granulated fertilizer is produced by extrusion molding, the amount of the lubricant used is a fertilizer containing lime nitrogen, urea and a lubricant. In addition, the lubricant was selected from lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, and salts of these fatty acids. Lime nitrogenous granular fertilizer characterized by using one or more types of fatty acids in combination with one or more types of fatty acid esters selected from glycerin fatty acid esters, succinic acid fatty acid esters, sucrose fatty acid esters, and sorbitan fatty acid esters It is a manufacturing method. In this case, the amount of lubricant used is preferably 0.6 to 1.3 parts by mass, and the mass ratio of fatty acids / fatty acid ester is preferably 0.2 to 1.0.

According to the present invention, the above object can be achieved.

The fertilizer containing lime nitrogen used in the present invention is lime nitrogen alone or a mixed raw material with fertilizer components such as molten phosphorous fertilizer, calcined phosphorous fertilizer, lime perphosphate, potassium chloride, and potassium sulfate. In the present invention, a predetermined amount of two specific types of lubricant is present in the fertilizer containing lime nitrogen and granulated using urea as a binder. The usage-amount of a lubricant is 0.4-2.0 mass parts per 100 mass parts in total of the fertilizer containing the said lime nitrogen, urea, and a lubricant. If the amount is less than 0.4 parts by mass, the pressure resistance during granulation increases. If the amount exceeds 2.0 parts by mass, the pressure resistance decreases too much, and in either case, granulation becomes difficult. A particularly preferable amount of the lubricant used is 0.6 to 1.3 parts by mass, and among them, the mass ratio of fatty acids / fatty acid ester is 0.2 to 1.0.

In the present invention, as a lubricant, one or more fatty acids selected from fatty acids or salts thereof and one or more fatty acid esters are used in combination. These may be added separately to the granulation raw material, or may be added after premixing.

Examples of the fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, and alkali metal salts or alkaline earth metal salts of these acids such as sodium, potassium, calcium, and magnesium. Particularly preferred is stearic acid. Examples of the fatty acid ester include glycerin fatty acid ester, succinic acid fatty acid ester, sucrose fatty acid ester, and sorbitan fatty acid ester. Of these, tristearin and distearin having a plurality of fatty acid esters in the molecule are preferable. Industrially, triacylglycerol is preferable.

It is preferable that the usage-amount of urea is 5-20 mass parts per 100 mass parts of fertilizers containing the said lime nitrogen, especially 8-12 mass parts.

The extruder used in the present invention can be any of a screw type, a rotary porous die, a rotary blade and the like. According to the molding method using a rotating porous die, a cylindrical granulated product having a diameter of about 3 mm and a length of about 2 to 7 mm is produced.

Examples 1-5
As fatty acids and fatty acid esters, stearic acid and glycerin fatty acid ester (both reagents) were selected and mixed together with a fertilizer containing lime nitrogen and urea at a ratio shown in Table 1. This mixed raw material is preheated at 85 ° C., and then extruded (rotary perforated die molding machine: “Disc Pelletta F-5” manufactured by Fuji Powder Co., Ltd.) to give a granular fertilizer (diameter of about 3 mm, length of 2 to 2). A cylindrical shape of about 7 mm) was manufactured.

Examples 6-14
Granulation was carried out in the same manner as in Example 1 except that the fatty acids and fatty acid esters were variously changed as shown in Table 2.

Comparative Examples 1-6
Granulation was performed in the same manner as in Example 1 except that the blending ratio of the mixed raw material was variously changed as shown in Table 3.

Comparative Examples 7 and 8
As shown in Tables 4 and 5, as the lubricant, two types selected from the group of fatty acids (Comparative Example 7) or two types selected from the group of fatty acid esters (Comparative Example 8) were used. Except for the above, granulation was performed in the same manner as in Example 1. In Comparative Example 8, the blending ratio of the mixed raw material was also changed.

In the above-mentioned Examples and Comparative Examples, the remaining state in the hopper showing the transportability of the mixed raw material (granulated raw material) was observed with the naked eye, and the time required for preheating was measured. Furthermore, the raw material fixation state in the granulator at the time of granulation was observed with the naked eye, and the active ingredients of the granulated product were measured. These results are shown in Table 6.

According to the Example of this invention, compared with the comparative example, the improvement of transportability and the shortening of the time required for preheating were attained. Moreover, the amount of lubricant used could be reduced. In Example 5 in which the mass ratio of fatty acids / fatty acid ester was 2.0, the time required for preheating was longer than in Example 1, but it was still possible to perform granulation with a shorter time than in Comparative Example.

On the other hand, in Comparative Example 1 in which the amount of the lubricant used was increased, the pressure resistance was excessively decreased, and in Comparative Example 2 in which the amount was decreased, the resistance was excessively increased. In either case, granulation was impossible.

When only fatty acids are used as a lubricant, in Comparative Example 3 in which the amount used is 1 part by mass, the pressure resistance increases too much and is fixed in the granulator, and the amount is increased as much as possible (Comparative Example 4). The preheating time was significantly increased. Moreover, when only fatty acid ester is used as a lubricant, in Comparative Example 5 in which the amount used is 10 parts by mass, the granulation raw material is fixed in the granulator and the amount is increased as much as possible (Comparative Example 6). The raw material remained in the hopper and the transportability deteriorated. Furthermore, the mixing of fatty acids (Comparative Example 7) and the mixing of fatty acid esters (Comparative Example 8) could not simultaneously achieve the effects of improving transportability and shortening the required preheating time.

There is provided a method for producing lime-nitrogenous granular fertilizer that can reduce the amount of raw material remaining in piping and hopper, can shorten the preheating time, and can reduce the amount of urea binder used.

Claims (2)

In the production of granulated fertilizer by mixing urea and lubricant in fertilizer containing lime nitrogen and extruding it, the amount of lubricant used is per 100 parts by mass in total of fertilizer containing lime nitrogen, urea and lubricant. 0.4 to 2.0 parts by mass, and the lubricant is one or more fatty acids selected from lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, and salts of these fatty acids. And one or more fatty acid esters selected from glycerin fatty acid esters, succinic acid fatty acid esters, sucrose fatty acid esters, and sorbitan fatty acid esters, in combination. The amount of the lubricant used is 0.6 to 1.3 parts by mass, and the mass ratio of fatty acids / fatty acid ester is 0.2 to 1.0. Manufacturing method.