JPS60251188A - Granular fertilizer and manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a granular fertilizer and a method for producing the same. More specifically, the present invention relates to a granular fertilizer obtained by mixing powdered fertilizer (excluding potassium sulfate) with a small amount of water in which a surfactant is dissolved or dispersed, and compressing and granulating the mixture, and a method for producing the same.

Generally, fertilizer granulation in recent years has been carried out for the purpose of improving fertilizer application workability and adapting to mechanical fertilization.

Today, most of the compound fertilizers are used in granular form. However, many of the single names are still used in powdered form. On the other hand, granular fertilizers are used in bulk blend fertilizers, which have recently become popular. Currently, various types of fertilizers are granulated using methods suited to their physical properties and provided to the market.

For example, granular urea is prilled in a prill tower or granulated in a granulator by known methods, and granular products are also provided for superphosphate or heavy superphosphate.

On the other hand, for fertilizers other than those mentioned above (excluding potassium sulfate, the same applies hereinafter), such as potassium chloride, ammonium sulfate, and ammonium chloride, there is a demand for effective granulation methods and provision of granular fertilizers. The above-mentioned fertilizers are generally produced by a compression granulation method, such as a method of compressing, disintegrating, and sieving using a roll press, etc., except in cases where a special granulation method has been established, such as for the above-mentioned urea.

However, regarding powdered fertilizers, especially single granulation,
There are various manufacturing and quality problems as described below. For example, in a dry granulation method in which powdered potassium chloride is mixed with a small amount of water and then compressed and granulated, the granulation properties of the potassium chloride are poor, so it is difficult to efficiently obtain granular products with a desired particle size range. It is difficult. When granular potassium chloride obtained by compressing and granulating a potassium chloride-water mixture using a roll press or the like is used as the raw material for the bulk blend fertilizer described above, granular chloride is produced during handling and transportation of the resulting bulk blend fertilizer. As a result of the pulverization of the potash portion, classification of the bulk blend fertilizer occurs, and segregation of fertilizing components by particle size becomes a problem.

Incidentally, as a raw material for compound fertilizers or bulk blend fertilizers based on organic fertilizers, 6 to 12 meshes of granular potassium chloride (note: the same applies to other single use cases) is generally used. In such applications, the granular potassium chloride obtained by the above-mentioned compression granulation method has undergone a process of compression, disintegration, and sieving, so its surface has many protrusions and its compression hardness is relatively high. The crushing surface is prone to wear. and,
During handling and transportation of the granulated product with flow, pulverization from the fragile sides of the individual particles occurs. Potassium chloride compressed and granulated using a roll press using the conventional method is used as a raw material for bulk blend fertilizer, but the pulverization rate of this product is approximately 10%, which is the average powder for practically usable granular fertilizers. This is significantly higher than the 2-3% conversion rate. For this reason, granular potassium chloride and other single items related to compression granulation have been re-discussed before bulk blending, and there is a demand for granular fertilizers that do not require such re-discussion.

Fertilizers are also generally used in their raw form, but
When farmers apply fertilizers such as potassium chloride, fertilizers that are powdery or contain a large amount of powder produce dust, which is harmful to the working environment. In addition, potassium chloride, which does not contain powder, is considered to be a cause of loss during fertilization and uneven fertilization due to fertilization due to wind and other factors. Therefore, for general farmers, it is necessary to keep the particle size as fine as possible without generating dust during fertilization, but in order to prevent uneven fertilization.

As a result of various studies in order to produce the above-mentioned desirable granular fertilizer, the present inventors have discovered that by mixing a small amount of water in which a surfactant has been dissolved or dispersed with powdered fertilizer, and compressing and granulating the mixture. The present invention (second invention) was completed knowing that the above-mentioned problems could be solved.

As is clear from the above description, an object of the present invention is to provide a compression granulation method for fertilizer with good granulation efficiency, and a fine granular fertilizer produced by the method that is less likely to powder during use. .

The present invention (second invention) has the following main configurations (1) and (5) and the embodiment configurations (2) to 4) and (6) to 8).

(1) Granular fertilizer made by mixing powdered fertilizer (excluding potassium sulfate) with a small amount of water in which a surfactant is dissolved or dispersed, and compressing and granulating the mixture.

(2) For powdered fertilizer (excluding potassium sulfate) and the fertilizer,
Said No. 1 (1) mixed with 0.03 to 1.0 wt % of water in which the surfactant was dissolved in o, ooi to 20 wt % and dissolved in 0.03 to 1.0 wt %.
) Granular fertilizers listed in section ).

(3) The granules according to item (1) above, wherein the surfactant is one or more selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. fertilizer.

(4) Powdered fertilizers such as potassium chloride, ammonium sulfate, ammonium chloride, ammonium phosphate, superphosphate lime 1
Heavy superphosphate lime, single burnt phosphorus, 2-oxo-4-methyl-
The above-mentioned (1) is prepared using one or more fertilizers selected from 6-ureidohexahydropyrimidine, isobutylidene diurea, oxamide, and urea-formaldehyde condensed fertilizer.
) Granular fertilizer as described in section.

(5) A method for producing granular fertilizer, which comprises combining powdered fertilizer (excluding potassium sulfate) and a small amount of water in which a surfactant has been dissolved or dispersed, and compressing and granulating the mixture.

(6) For powdered fertilizers (excluding potassium sulfate) and the fertilizers,
The above step (5) is mixed with 0.03 to 1.0% by weight of water in which 0.001 to 20% by weight of a surfactant is dissolved or dispersed.
) The method for producing granular fertilizer as described in item 1.

(7) The granules according to item (5) above, wherein the surfactant is one or more selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Fertilizer manufacturing method.

(8) Powdered fertilizers such as potassium chloride, ammonium sulfate, ammonium chloride, ammonium phosphate, superphosphate lime 1
Heavy superphosphate lime, single burnt phosphorus, 2-oxo-4-methyl-
6-Ureidohexahydropyrimidine, imbutylidene diurea, oxamide, and urea-formaldehyde condensed fertilizer.
) The method for producing granular fertilizer as described in item 1.

As the powdered fertilizer used in the present invention, fertilizers other than potassium sulfate described below can be used.

That is, they include, for example, potassium chloride, ammonium sulfate, ammonium chloride, ammonium phosphate, 9-fold lime superphosphate, 1-fold calcined phosphorus, 2-oxo-4-methyl-6-ureido hexahydropyrimidine (trade name CD
U), isobutylidene diurea (trade name IBDtl)
, oxamide, urea-formaldehyde condensation fertilizer, or a combination of two or more of these fertilizer ingredients can be used.

The degree of powderiness, that is, the particle size, of such fertilizer raw materials for granulation is not limited, and either granules, powders, or a mixture thereof can be used. However, in relation to the particle size of the target product, it is usually less than 60 mesh pass, preferably 8
It is about 0 mesh pass or less and 300 mesh pass or more. In the above explanation, the significance of granulating granular fertilizer as a raw material lies in the difference in physical properties (hardness, pulverization rate, etc.) between the raw material granule and the product granule.

Compression granulation according to the present invention is possible even if coarse particles such as 80 mesh are used, but the yield of granular products is reduced because the miscibility with water in which the surfactant is dissolved or dispersed is somewhat reduced. There is a tendency for the powdering rate to decrease somewhat and the powdering rate to increase slightly.

The surfactant used in the present invention is an anionic type as long as it dissolves or disperses in water.

Any of cationic, nonionic and amphoteric surfactants can be used. However, the types of these surfactants are
Select and use fertilizers that are compatible with the chemical properties of the fertilizer being applied. For example, when anionic surfactants are applied to fertilizers containing large amounts of divalent or trivalent metal ions, such as lime superphosphate, the surfactants react with these metal ions and become insolubilized. , the surfactant effect is impaired. Therefore, it is desirable to use nonionic surfactants for such fertilizers. The surfactant is used by dissolving or dispersing it in water in a predetermined amount, and the concentration of the surfactant in the aqueous solution or dispersion thus obtained is 0.001 to 50% by weight, preferably 0.05 to 20% by weight.
Weight%. If it is less than 0.001% by weight, the effect of the present invention is insufficient, and if it exceeds 50% by weight, there is not only no improvement in the effect, but also the viscosity of the water in which the surfactant is dissolved or dispersed increases. The miscibility of powdered fertilizer with water is not preferable because, for example, when the surfactant liquid is sprayed onto granular potassium sulfate, it is difficult to form fine droplets into a mist or it tends to be defective.

The mixing of the powdered fertilizer used in the present invention with a small amount of water in which a surfactant is dissolved or dispersed is not limited as long as the mixing can be carried out uniformly. For example, the surfactant (or dispersion) may be sprayed onto powdered fertilizer that is being stirred or fluidized in a mixer, or the above-mentioned mist may be sprayed onto powdered fertilizer falling in a tower. Put on.

The ratio of water used as a surfactant solution (or dispersion) to the powdered fertilizer is 3% by weight or less, preferably 0.01 to 1.0% by weight, more preferably 0.1 to 0% by weight.
．． It is 7% by weight. When the proportion of water used in the compression granulation (dry compression granulation) according to the present invention is greater than the above-mentioned range, undesirable physical properties of the granular fertilizer product, such as increased caking, will occur. In addition, the effect of improving powderability becomes insufficient, and a separate drying step is required to prevent this, and one of the advantages of the dry method is lost. On the other hand,
When the proportion of water used is 0.01% by weight without swirling, it becomes difficult to evenly wet the surface of the raw material powdered fertilizer with the surfactant solution (or dispersion), resulting in improved granulation efficiency and Both the improvement in powderability is insufficient.

As an exception to the above usage ratio of water and powdered fertilizer, when two or more powdered fertilizers are mixed and moistened, double chlorination and other reactions progress between some of the fertilizer ingredients, and the mixed water A larger amount of water may be required as some of the water is fixed as water of crystallization.

The mixing conditions of the surfactant solution (or dispersion) and powdered fertilizer are not limited, but the mixing conditions are at room temperature to 100°C for 5 minutes to 1 hour (in the case of a batch method) or 10 seconds to 3 minutes (in the case of a continuous method). time).

The powdered fertilizer-surfactant solution (or dispersion) mixture according to the present invention obtained as described above is subsequently fed to a compression granulator and granulated. The granulator used is not limited, but includes, for example, a roll press, a briquette machine, or a tablet machine. However, the effects of the present invention are particularly remarkable when a roll press is used. Incidentally, roll press refers to a method in which a pressure of several tons/cm is applied to the rolls used, the raw material to be granulated is passed between the rolls, compressed into a plate shape, and then crushed to obtain granular products. .

The thus obtained crushed product is divided into preferred particle sizes using a sieve, such as a vibrating sieve, and those with suitable particle sizes are obtained as a product.

In the case of the granular fertilizer according to the present invention, examples of the particle sizes are 6 to 12 meshes (grain amount) and 12 to 60 meshes (fine particle amount). What are Tagushi 6-12?

The 12 meshes that distinguish between the 0-grain product and the fine grain amount, which means 6 mesh passes and 12 meshes, may be of other sizes (for example, 24 meshes) depending on the case.

In the case of the aforementioned particle size, the oversized product of 6 mesh-on or the undersized product of BO mesh pass is crushed or re-roll pressed as required. However, if a fine grain amount that can be applied directly to the field, for example 60 to 70 mesh, is desired, an additional sieving of 80 mesh passes is carried out. With regard to this additional sieving, in the compression granulated products of the conventional method, the sieves are easily clogged and the sieve cannot be operated for a long period of time, but the products according to the method of the present invention have very little clogging, so the 80 to 70 The amount of fine mesh particles can also be produced without any problem.

The above steps will be explained using figures.

In the figure, fertilizers supplied from pipes 1 and 2 are mixed in mixer A, and the mixture passes through pipe 4 and spray nozzle B in an intermediate falling state via raw material supply pipe 3 to hopper C. The atomized surfactant aqueous solution or water is sprayed through the hopper C to make the surface wet, and the surface is then sent to the hopper C. The wet particles in hopper C are sent via pipe 3° to screw feeder D and then fed to roll press E to form flakes. The flakes are sent to a crusher @F via a belt conveyor 5, where they are crushed, and sent to a vibrating sieve G via a packet elevator 6 as a mixture of granules and powder. The vibrating sieve contains 6 meshes from top to bottom (same for Tyler and below).

12 mesh and 60 mesh sieves are installed. The mixture treated with this sieve is sieved in the order of particle size into oversized particles, fine particles, and returned powder. The oversized product is then circulated through the oversized product piping 8 to the crusher F, and the returned powder is returned to the supply piping 3 to the hopper C via the return powder piping 7. The amount of other particles and the amount of fine particles are obtained as products from product piping 9 and product piping 10, respectively.

The first effect of the present invention is that the efficiency of granulation is good. That is, as is clear from Example 2 and Comparative Examples 3 and 4, which will be described later, the efficiency of granulation according to the method of the present invention reaches as much as 80% in terms of the amount of granules and fine particles. Alternatively, even if the method of the present invention is carried out in the same manner as the method of the present invention except that only a small amount of water is mixed, the efficiency does not reach 60%.

The second effect of the present invention is that the obtained granular product has a high hardness and a low pulverization rate. That is, as is clear from Examples 1.3 to 5 and Comparative Examples 1 and 2.5 to 10, which will be described later, the hardness (compression rupture pressure) of the products of the present invention is about 20 to 40% higher than the corresponding comparative examples. , powdering rate is 1-2
%, significantly less than the 4-7% of each comparison.

The present invention will be explained below with reference to Examples and Comparative Examples.

Example 1. Comparative Example 1 While mixing industrial potassium chloride using a mixer, water in which 0.5% by weight of a nonionic surfactant (hexaoxyethylene n-octylphenyl ether) was dissolved was added to the potassium chloride. It was mixed by spraying with a 0.3% by weight sprayer. The resulting mixture was mixed with low Ay-j less C71y Kusa 7.
'i' set, WP 400X 400 type) under piston oil pressure of 300 kg/crn' to form flakes.

The resulting flakes were crushed using a crusher, and the crushed products were then sieved using a vibrator to obtain 6 to 24 mesh (Tyler) granules, and the hardness and pulverization rate of the granules were measured.

In addition, for comparison of the effects of the present invention, a case where no aqueous solution of surfactant was used (Comparative Example 1) and a case where the same amount of water as the solution was used instead of the aqueous solution of surfactant (Comparative Example 2) For each, granular products were obtained under the same conditions except for the hardness and powdering rate were measured.

The compression granulation conditions and measurement results of hardness and pulverization rate are shown in Table-■.

Table - ■ Example 2 and Comparative Examples 3 to 4 0 nonionic surfactant (hexaoxyethylene n-octylphenyl ether) was added to the industrial potassium chloride raw material and the powder returned from the granulation process. The raw materials were mixed by spraying 0.3% by weight of water with a 0.5% by weight solution using a sprayer. The amount of raw materials, including the returned powder, was set so that the amount fed to the roll press was 2.0 tons/hour, but the amount of raw materials also corresponded to the total amount of grains and fine grains, that is, the product amount.

A certain amount (2,
The mixture was continuously supplied to a roll press (Alexander set, WP 400X 400 type) and compressed and granulated into flakes under a piston oil pressure of 300 kg/crn'.

The obtained flakes are crushed with a crusher, and the crushed products are then sieved with a vibrating sieve (6 meshes in the upper row, 12 meshes in the middle row, 60 meshes in the lower row, each area 2.8 square meters) to obtain particles of 6 to 12 meshes. A fine grain amount of 12 to 60 mesh was obtained. This is a continuous operation device in which oversized products with a 6-mesh sieve are crushed again in the crusher, and undersized products with a 60-mesh sieve (return powder) are circulated to a roll press. be.

The obtained grain size and fine grain size were each stored in a silo with a capacity of 50 tons, and then filled into a flexible container and weighed, and the proportion of powder mixed into the fine grain size was measured.

In order to compare the effects of the present invention, the other conditions were the same for each case: when no surfactant aqueous solution was used (Comparative Example 3), and when the same amount of water was mixed with the surfactant aqueous solution (Comparative Example 4). The mixture was compressed and granulated, and measurements were taken.

The results are shown in Table II.

Table II Examples 3 to 5. Comparative Examples 5 to 10 Industrial ammonium sulfate instead of industrial potassium chloride, c
Rinkaan containing nu (product name) and CDU (product name)
(15-15-15-OH trade name) as raw material, Table -■
Table 1 shows the results of measuring the hardness and powdering rate of granular products obtained in the same manner as in Example 1 and Comparative Example 1, except that the surfactant types, concentrations, and mixing ratios were mixed as shown in Table 1. Shown below.

front - mouth

[Brief explanation of drawings]

The figure is a flow sheet showing the manufacturing process of the method of the present invention. In the figure, A...Mixer B...Spray nozzle C...Hopper D...Screw feeder E...Roll press F...Crusher G...Vibration sieve 3: Raw material supply piping 5 : Belt conveyor 6: Packet elevator 7: Return powder piping 8 Niover size product piping. Patent applicant: Chisso Co., Ltd. Representative Patent Attorney Yatabe Sasai Katsuhiko Uenonaka

Claims (8)

[Claims] (1) Granular fertilizer made by mixing powdered fertilizer (excluding potassium sulfate) with a small amount of water in which a surfactant is dissolved or dispersed, and compressing and granulating the mixture. (2) For powdered fertilizer (excluding potassium sulfate) and the fertilizer,
The granular fertilizer according to claim 1, wherein 0.03 to 1.0% by weight of water in which 0.001 to 20% by weight of a surfactant is dissolved or dispersed is mixed. (3) In claim (+), the surfactant is one or more selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. Granular fertilizer as described. (4) Powdered fertilizers such as potassium chloride, ammonium sulfate, ammonium chloride, ammonium phosphate, and phosphorus-resistant lime 1
Heavy superphosphate lime double calcined phosphorus, 2-oxo-4-methyl-
The granular fertilizer according to claim (1), which uses one or more fertilizers selected from 6-ureidohexahydropyrimidine, imbutylidene diurea, oxamide, and urea-formaldehyde condensed fertilizer. (5) A method for producing granular fertilizer, which comprises mixing powdered fertilizer (excluding potassium sulfate) with a small amount of water in which a surfactant has been dissolved or dispersed, and compressing and granulating the mixture. (6) For powdered fertilizers (excluding potassium sulfate) and the fertilizers,
The method for producing granular fertilizer according to claim (5), wherein 0.03 to 1.0% by weight of water in which 0.001 to 20% by weight of a surfactant is dissolved or dispersed is mixed. (7) Claim (5) wherein the surfactant is one or more selected from anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants. The method for producing the granular fertilizer described. (8) Powdered fertilizers such as potassium chloride, ammonium sulfate, ammonium chloride, ammonium phosphate, superphosphate lime9
Heavy superphosphoric acid lime 9-weight burnt phosphorus, 2-oxo-4-methyl-
The method for producing a granular fertilizer according to claim (5), which uses one or more fertilizers selected from 8-ureidohexahydropyrimidine, imbutylidene diurea, oxamide, and urea-formaldehyde condensed fertilizer.