JPS62113786A - Manufacture of rod form fertilizer - 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 novel method for producing rod-shaped fertilizers.

More specifically, the present invention relates to a method for producing a slow-release rod-shaped fertilizer, which comprises adding calcium carbonate, bentonite, and water to an inorganic fertilizer, mixing the mixture, molding the mixture into a rod-shape, and solidifying the mixture.

Conventionally, the most effective method for general tree planting, especially for growing shrubs (such as foliage trees, fruit trees, tea trees, and mulberry trees) is to apply fertilizer to the deep layers of the soil. Alternatively, it is well known that a method such as driving a rod-shaped container filled with fertilizer into the soil is used as a form of reducing the number of liquid fertilizers and increasing the fertilizer effect effectively.

However, these methods have the disadvantages that they require special equipment, that the containers are expensive to manufacture, and that operations such as measuring, filling, and shaping are time-consuming.

The inventors of the present invention have conducted various research on methods for manufacturing rod-shaped relics with appropriate strength by solidifying fertilizer raw materials.The inventors have found that by adding a forming accelerator to the fertilizer raw materials, they can be easily extruded from the molding machine, and the surface of the fertilizer raw materials can be easily extruded. The present invention has been completed by establishing a method for producing a slow-release rod-shaped fertilizer that does not require a container, which has moderate slipperiness, is easy to dry, and has a hardness that does not break even when driven into the deep layer of soil.

Fertilizer raw materials used in the present invention include ammonium phosphorus as a nitrogen source,
Ammonium sulfate or the like can be used as a phosphoric acid source, potassium sulfate or potassium chloride can be used as a potassium source, and a small amount of magnesium fertilizer or trace element fertilizer can also be added in combination.

Calcium carbonate and bentonite are used together as forming accelerators, but when mixed with fertilizer raw materials, calcium carbonate decomposes slightly in acidity, generates carbon dioxide gas, and forms calcium salts, which provide binding strength. to improve the hardness of the product. On the other hand, bentonite swells when the montmorillonite particles that make up the particles contain interlayer water between its flaky crystals, giving the product lubricity and plasticity. In other words, when the fertilizer raw material containing bentonite is kneaded, it becomes plastic, which reduces the extrusion pressure of the molding machine and increases the extrusion speed.
Moreover, it is useful for suppressing the occurrence of scratches on the surface of the extruded product.

The amount of calcium carbonate and bentonite added is as follows:
Calcium carbonate is 5 parts by weight per 100 parts by weight of inorganic fertilizer raw materials, calcium carbonate, bentonite and water.
The most preferred addition ratio is 15 parts by weight and 5 to 10 parts by weight of bentonite. The influence of the blending ratio of these molding accelerators on the physical properties of the product can be seen in Table 2 of Examples below. When the addition ratio is outside the range of 5 to 15 parts by weight of calcium carbonate and 5 to 10 parts by weight of bentonite,
The commercial value of this product is likely to be impaired in terms of moldability, surface smoothness, hygroscopicity, dryness, hardness, and inorganic fertilizer raw materials (nitrogen, phosphoric acid, active ingredient content, etc.).

When mixing and purifying, if the amount of water added is excessive, the drying properties after molding will be poor and forced drying with hot air will be required. Against, 8~
In the range of 15 parts by weight, air drying is sufficient to achieve the purpose.

The molding method may be compression molding using a mold or extrusion molding, but extrusion molding is generally more advantageous in terms of workability and economy. A rod-shaped fertilizer of the size can be made by extrusion molding.

Next, the present invention will be described with specific examples, but the present invention is not limited to these.

Daidome ■Ammonium sulfate, ammonium phosphate, as fertilizer raw materials,
Potassium sulfate, calcium carbonate, and bentonite were prepared as forming accelerators, and they were weighed and mixed to a total of about 6 kg according to the respective basic units so as to have the designed components listed in Table 1 below.

Next, water was added to the mixture at room temperature, and the mixture was kneaded with a kneader. This kneaded material was passed through a W-screw extruder with a diameter of 20 m.
The fertilizer was extruded into a round bar with a diameter of 1.5 m, cut into lengths of about 150 mm using a cutter, and left to dry naturally in a room at a temperature of about 25°C for about 72 hours to obtain each sample of bar-shaped fertilizer with a moisture content of 9.5 to 10.0%. Ta. Physical properties of this sample, such as difficulty in extrusion, appearance (shape, surface texture), hardness, and moisture absorption, were measured and compared.

The results are shown in Table 2.

The hardness and moisture absorption values in Table 2 are average values of five samples of the same composition.

Table 1 (Example of raw material composition) % Fertilizer raw material % Molding accelerator % Design component % No. Sulfur phosphorus sulfur sulfur carbon Bent water Anka Cal night AN
SP meeting P 匈NI 1 38
25 21 5 0 11 12.
810.3 9.610.42 36 24
20 s s 1o12.0 9.
7 9.0 9.83 34 22 18
5 10 11 11.3 9.1
8.4 9.14 36 24 20 1
0 0 10 12.0 9.7 9.
0 9.85 34 22 18 10
5 11 11.3 9.1 8.4
9.16 31 21 17 10 10
11 10.5 8.5 7.9 8
．． 57 34 22 18 15 0
11 11.3 9.1 B, 4 9.
18 31 21 17 15 5 1
1 10.5 8.5 7.9 8.59
29 19 16 15 10 11
9.7 7.9 7.3 7.9 Ammonium sulfate:
ammonium sulfate, sulfurized: potassium sulfate phosphorus ammonium: ammonium phosphate, carbonaceous: calcium carbonate AN: ammonia nitrogen, sP: soluble phosphoric acid WP: water-soluble phosphoric acid,
WK: Water-soluble potash Table 2 (physical properties of molded products) No., depending on molding machine Appearance Hardness Moisture absorption Difficulty in extrusion (shape, surface texture) Kg %1
Unable to extrude, clogged □ -□ 2 Slightly difficult Surface roughness 102 1.
323 Good Good
118 1.254 Unable to extrude, clogged □ -
□ 5 Somewhat difficult Surface roughness 150 1.
286 Good Good
161 1.097 Unable to extrude, clogged □
-□ 8 Unable to extrude, clogged □ -□ 9 Good Good 16
8 1.10 In Table 2, the difficulty of extrusion by a molding machine is the difficulty level when the raw material mixture is compressed by a W-screw and extruded from a Gui (mouth mold). It is almost impossible to extrude, and "difficult" means that it is difficult to extrude and has a negative effect on the appearance of the molded product.

The appearance column indicates the condition of the surface of the product extruded by the molding machine, and "roughness" refers to cracks in the circumferential direction of the surface,
This means the occurrence of scratches such as shark fins or scales, which significantly reduces commercial value.

The hardness is measured by measuring the hardness of the product in the cylindrical direction using a Shimadzu Autograph Model S-2000.

The desired hardness varies depending on the soil condition to be fertilized, and since the tip of the molded fertilizer is sharpened to make it easier to drive, a rod-shaped fertilizer with a diameter of 20 mm can be used in practical use if it weighs 100 kg or more without breaking.

Moisture absorption is calculated as the percentage increase in weight after the bar-shaped fertilizer of each sample is left for 24 hours at a room temperature of 23°C and a relative humidity of 100%.
%).

Moisture absorption affects the slow-release properties of fertilizers and changes in surface skin over time after being left indoors, but as a reference value, if it is within 2%, there is no practical problem. In addition, if the rod-shaped fertilizer itself is molded and then covered with a heat-softening material such as paraffin wax or a thermosetting material such as shrink film, the moisture absorption will be reduced by 1%.
It can be suppressed to below and exhibits more preferable physical properties. For example, a heated melt of paraffin wax (melting point: approximately 65°C)
), the moisture absorption was 0.4%.

Claims (2)

[Claims] (1) A method for producing a slow-release rod-shaped fertilizer, which comprises adding and mixing calcium carbonate, bentonite, and water to an inorganic fertilizer raw material, forming the mixture into a rod-shape, and solidifying the mixture. (2) Claim 1: Calcium carbonate is added in an amount of 5 to 15 parts by weight and bentonite is added in an amount of 5 to 10 parts by weight relative to 100 parts by weight of the total amount of inorganic fertilizer raw materials, calcium carbonate, bentonite, and water. Method for manufacturing the fertilizer described in Section 1.