JP2017119588A - Manufacturing method of spherical fertilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a spherical fertilizer formed to a spherical shape by using a particle size regulation machine after adding urea and a lubricating material to a powder component of a lime nitrogen-based fertilizer and granulating to a granular shape or a lump shape under a temperature condition wherein the urea is softened.SOLUTION: There are provided (1) a manufacturing method of a spherical fertilizer by adding 5 to 30 mass% of urea and 0.5 to 5 mass% of a lubricating material to 65 to 95.5 mass% of powder consisting of a lime nitrogen and one or more kind selected from a soluble phosphate fertilizer, a burned phosphate fertilizer, ammonium phosphate, potassium chloride and potassium sulfate, granulating to a granular shape or a lump shape under a temperature condition of 105 to 140°C wherein the urea is softened and then forming the same to a spherical shape under rolling speed of 3 to 6 m/sec. and temperature of 105 to 140°C with using a size regulation machine, (2) a manufacturing method of the spherical fertilizer according to (1) wherein the melting point of the lubrication material is 40 to 80°C and (3) a manufacturing method of the spherical fertilizer according to (1) or (2) wherein particle diameter after size regulation is 1 to 8 mm.SELECTED DRAWING: None

Description

  In the present invention, urea is added as a binder to a powder fertilizer component such as lime nitrogen, and granulation and sizing processing is performed in a temperature range where this softens without adding a solvent such as water (including steam) or acetone. The present invention relates to a method for producing the resulting lime nitrogen-based spherical fertilizer.

  Lime nitrogen-based fertilizers are generally powdered fertilizers, but have problems such as scattering during spraying. In order to improve this defect, for example, granular fertilizer pelletized by an extrusion granulator is used, but since the pellet has corners, the angle of repose is large, so there is a risk of causing bridging in the spreader and the corners are There was also a problem of scraping and generating dust.

  In order to solve such a problem, it has been proposed to add water and / or an organic solvent to the powdered fertilizer and then form it with a spherical granulator (see Patent Documents 1 and 2). In addition to the problem that the cyanamide component is reduced, a drying process for removing water and organic solvents is required.

Japanese Patent No. 3127308 JP 2001-322888 A

In the present invention, urea and a lubricant are added to the powder component of lime nitrogen fertilizer, and after granulating it into a granule or a lump under a temperature condition where urea softens, it is shaped into a spherical shape using a granulator. A method for producing a spherical fertilizer is provided.

  That is, the present invention relates to (1) powder 65 to 95.5 consisting of lime nitrogen and at least one selected from the group consisting of molten phosphorous fertilizer, calcined phosphorous fertilizer, ammonium phosphate, potassium chloride, and potassium sulfate. Add 5-30% by weight of urea and 0.5-5% by weight of lubricant to 10% by weight, granulate into granules or lumps under the temperature condition of 105-140 ° C. where urea is softened, and then use a granulator And a method for producing a spherical fertilizer, which is formed into a spherical shape under conditions of a rotational speed of 3 to 6 m / sec and a temperature of 105 to 140 ° C., (2) the melting point of the lubricant is 40 to 80 ° C. A method for producing a spherical fertilizer, (3) a method for producing a spherical fertilizer according to (1) or (2), wherein the particle size after sizing is 1 to 8 mm.

  By using the spherical fertilizer of the present invention, rolling resistance is low, and uniform spraying is possible when mechanically spraying at a farm. Moreover, since the crushing strength is high and it is not pulverized at the time of transportation or spraying, it has the effect of being easy to handle without scattering.

Hereinafter, the present invention will be described in detail.
Parts and% used in the present invention are based on mass unless otherwise specified.

As a fertilizer component used in the present invention, lime nitrogen alone or lime nitrogen is an essential component, which includes one or more of molten phosphorous fertilizer, calcined phosphorous fertilizer, ammonium phosphate, potassium chloride, and potassium sulfate. Mixed fertilizer.

The urea of the present invention is softened when the powder fertilizer component is granulated and sized, and serves as a binder. The addition amount of urea needs to be contained in the spherical fertilizer in an amount of 5 to 30%, and more preferably 8 to 20%. If it is less than 5%, there is a problem that the crushing strength of the fertilizer particles is low and the yield due to pulverization is large, and if it exceeds 30%, the fluidity becomes too high and granulation cannot be performed.

The lubricant used in the present invention functions to increase the fluidity of the powder fertilizer component as a raw material, prevent the raw material from adhering to the production apparatus, and further assist the binder.
The lubricant is not particularly limited, and known ones can be used, but it is preferable that the fertilizer use has low toxicity. The melting point must be 40-80 ° C. A lubricant having a melting point exceeding 80 ° C. cannot increase the fluidity of the powder fertilizer, and a lubricant having a melting point of less than 40 ° C. is not only difficult to handle, but also reduces the strength of the spherical fertilizer.
Specific examples of the lubricant include fatty acids such as lauric acid, myristic acid, palmitic acid, stearic acid, acid, petrolatum, paraffin, isoparaffin, and the like. Of these, stearic acid is preferred.
Moreover, the hydrogenated oil obtained by carrying out addition reaction of hydrogen to rapeseed oil, cottonseed oil, soybean oil, beef tallow, etc. is mentioned. Of these, hydrogenated soybean oil is preferred.
A lubricant may be used alone or in combination of two or more. The added amount needs to be contained in the spherical fertilizer by 0.5 to 5%. A more preferable addition amount is 0.6 to 3.0%. If it is less than 0.5%, the fertilizer component may be clogged in the die or the like in the granulation step. If it exceeds 5%, the fluidity may be too high to granulate.

  The fertilizer component of the present invention may be added with other components such as hydroxylated clay, calc sinter (lime flower), converter slag, calcium phosphate, ammonium sulfate, ammonium sulfate, rice bran as required.

The granulator used for pelletization in the present invention is, for example, an extrusion granulator such as a screw type extruder, a rotary die type extruder, a rotary blade type extruder, a compression roll type, a briquette type or a tablet type. A compression granulator etc. are mentioned. It is preferable to use a rotary die type extruder as the granulator of the present invention because of the small amount of powder generation and the crushing strength of the generated pellets.

  When a rotary die type extruder is used, the raw material to be supplied is sandwiched between a fixed disk die and a rotating roller, and extruded from the hole of the disk die to the lower part while being pressurized with a pressure of 15 to 20 MPa at maximum. Molded. The hole diameter of the disk die is preferably 2 to 6 mmφ. It is cut into a suitable length by a knife cutter that rotates on the back side of the disk die, and is discharged into pellets.

The operating conditions of the granulator are not particularly limited. You may change according to the production amount of a fertilizer component, a composition, and the scale of a granulator. For example, it is kneaded in the range of 1 to 100 Hz. The fertilizer component needs to be granulated in a temperature range of 105 to 140 ° C. The heating method is not particularly limited. For example, the fertilizer component is heated by shearing heat generated during granulation after passing through a preheater. A preferred temperature range is 110-138 ° C. Below 105 ° C., urea does not melt and does not function as a binder and cannot be pelletized. If it exceeds 140 ° C, urea may be thermally decomposed.

  The granulator used for spheroidization in the present invention is not particularly limited. Known devices such as a Malmerizer, a rotary tablet machine, a rolling type granulator, a nepular sizer, and a new gramming machine are used. From the fact that the amount of powder generated is small and the crushing strength of the generated pellets, a Malmerizer is preferably used as the granulator of the present invention.

  The irregular and angular pellets after granulation have the same length due to impact and shear due to the rotation of the plate with uneven grooves in the Malmerizer. Furthermore, the corners are removed due to rolling and friction in the vortex, and the spheroidization progresses, resulting in a spherical shape. The cutting powder generated at this time is adsorbed by the granulated material, and therefore does not finally remain. The size of the uneven groove of the plate is not particularly limited. For example, it is a polyhedron such as a cubic body or a rectangular parallelepiped having a height of 2 to 6 mm and a width of 2 to 6 mm.

The operating conditions of the granulator of the present invention may be changed according to the production amount of fertilizer components, the composition and the scale of the granulator, but it is necessary to rotate at a speed of 3 to 6 m / sec. If it is less than 3 m / sec, the sizing effect is low and spheroidization is difficult. If it exceeds 6 m / sec, the granulated fertilizer is excessively shaved and the yield decreases. The fertilizer component needs to be sized in a temperature range of 105 to 140 ° C.
The heating method is not particularly limited. For example, the fertilizer component is kept warm after being discharged from the granulator and supplied to the granulator. A preferred temperature range is 110-135 ° C. Below 105 ° C., urea does not melt and does not function as a binder and cannot be spheroidized. If it exceeds 140 ° C., urea may be thermally decomposed, which causes a decrease in nitrogen content.
The spherical fertilizer of the present invention preferably has a particle size of 1 to 8 mm after sizing.

  The present invention will be described more specifically with reference to experimental examples below, but the present invention is not limited to these experimental examples.

"Example 1"
<Production of granular fertilizer>
Lime nitrogen (24% nitrogen content: Denka) 80%, urea (reagent) 17%, soybean hardened oil (reagent) 2%, and stearic acid (reagent) 1% are preheated to 80 ° C, followed by rotary die extrusion A granular fertilizer was produced by granulating at 50 Hz using a machine (disc pelleter T-5: manufactured by Dalton). The product temperature rose to 125 ° C.

<Production of spherical fertilizer>
The granular fertilizer was immediately charged (at an article temperature of 120 ° C.) into Malmerazer QJ-400 (manufactured by Dalton) and sized under a speed condition of 3.5 m / sec.

<Measurement method>
Powder rate measurement: A sample after sizing was collected and sieved to measure a powder rate of less than 1 mm.
Particle size distribution: Samples after sizing were collected and sieved to measure the ratio of 1 to 4 mmφ and 4 to 8 mmφ.
Total agricultural-type pulverization rate measurement: 100 g of a sample from which sieving powder has been removed with 16 mesh is weighed and placed in a porcelain pot. Three magnetic balls (105 g) are put into this. The porcelain pot is rotated on a rotating roll at a speed of 75 rpm for 15 minutes. A sample is taken out, a pulverized product of 16 mesh or less is collected, and its mass A is determined. The powdering rate was calculated according to the following formula and listed in Table 1.
Powdering rate (%) = A (g) ÷ 100 (g) × 100 (1)
Crushing strength: 10 to 20 grains are arbitrarily taken out and measured with a Kiya type grain hardness meter. The average hardness values are shown in Table 1.

"Example 2"
The granular fertilizer after granulation of “Example 1” was allowed to stand for 3 minutes, the product temperature at the time of granulation was lowered to 105 ° C., and the same test as in “Example 1” was performed.

"Example 3"
The composition of the fertilizer of “Example 1” is 50% lime nitrogen (nitrogen content 24%: manufactured by Denka), 2315% molten phosphorus fertilizer (“Yorin”: manufactured by Hinode Chemical Co.), 5% potassium chloride (reagent) , Potassium sulfate (reagent) 10%, urea (reagent) 17%, soybean hardened oil (reagent, melting point 68 ° C.) 2%, stearic acid (reagent, melting point 70 ° C.) 1%, the same as “Example 1” The test was conducted.

Example 4
The same test as in “Example 1” was performed by reducing the lime nitrogen of “Example 1” (nitrogen content: 24%: Denka) to 74% and increasing the urea (reagent) to 23%.

"Example 5"
The same test as in “Example 1” was performed by increasing the lime nitrogen of “Example 1” (nitrogen content 24%: manufactured by Denka) to 91% and reducing urea (reagent) to 6%.

“Comparative Example 1”
The same test as in “Example 1” was carried out without adjusting the granular fertilizer of “Example 1” (without spheroidizing).

“Comparative Example 2”
The preheating step of “Example 1” was omitted, and granulated fertilizer was produced by granulating at 50 Hz using a rotary die extruder (Disk Pelleter T-5: manufactured by Dalton). The product temperature was 105 ° C.
When the granular fertilizer was put into Malmerazer QJ-400 (manufactured by Dalton Co.) at a product temperature of 95 ° C. and sized under the condition of 50 Hz, a spherical fertilizer was obtained. A test similar to “Example 1” was performed.

“Comparative Example 3”
When the rotational speed of the granulator of “Example 1” was increased from 3.5 m / sec to 7.5 m / sec, a spherical fertilizer was obtained. A test similar to “Example 1” was performed.

“Comparative Example 4”
A granulation test was conducted at 50 Hz using a rotary die type extruder (Disc Petter T-5: manufactured by Dalton) without adding the soybean hardened oil (reagent) and stearic acid (reagent) of "Example 1". However, the hole in the disk was clogged immediately and granulation was not possible.

“Comparative Example 5”
The lime nitrogen of “Example 1” (nitrogen content 24%: manufactured by Denka) was increased to 94%, urea (reagent) was reduced to 2%, and a granulation test was performed at 50 Hz using a rotary die extruder. However, since there was little urea as a binder, the powder was not collected and granulation was not possible.

“Comparative Example 6”
The lubricant of “Example 1” was changed to 3% ethylene bisamide (wax EB-F, Kao Corp., melting point 145 ° C.) 3%, and a granulation test was conducted at 50 Hz using a rotary die extruder. Since it did not melt, the powder was not collected and granulation was not possible.

“Comparative Example 7”
The granulation test was conducted at 50 Hz using a rotary die extruder with the lubricant of “Example 1” changed to 3% hardened palm oil (reagent, melting point 33 ° C.) 3%. Thereafter, the same test as in “Example 1” was performed.

  It can be seen from Table 1 that the present invention can obtain a spherical fertilizer that does not powder when dispersed at a farmer and does not pulverize or disintegrate due to the impact and friction of mechanical spraying without using water or a solvent as a binder.

  By using the spherical fertilizer of the present invention, the rolling resistance is low, it is possible to uniformly spread when farming with a farmer, and the crushing strength is high, and it does not re-pulverize during transportation or spraying, so it is handled without scattering. Since it has the effect that it is easy, it can be used widely for agriculture.

Claims (3)

Powder of 65 to 95.5% by mass selected from lime nitrogen and one or more selected from molten phosphorous fertilizer, calcined phosphorous fertilizer, ammonium phosphate, potassium chloride and potassium sulfate, and 5 to 30 mass of urea % And a lubricant of 0.5 to 5% by mass and granulated into granules or agglomerates under a temperature condition of 105 to 140 ° C. at which urea is softened, and then using a granulator, a rotational speed of 3 to 6 m / A method for producing a spherical fertilizer, which is formed into a spherical shape under conditions of a second and a temperature of 105 to 140 ° C. The method for producing a spherical fertilizer according to claim 1, wherein the melting point of the lubricant is 40 to 80 ° C. The method for producing a spherical fertilizer according to claim 1 or 2, wherein the particle size after sizing is 1 to 8 mm.