JPH0134959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a granular composite fertilizer by mixing and granulating various fertilizer raw material powders and drying the mixture. The fertilizer raw material powder referred to in the present invention refers to chemical fertilizers such as ammonia sulfate, ammonium nitrate, urea, lime superphosphate, ammonium phosphate, and potassium chloride, and organic fertilizers such as oil cake and fish meal. Compound fertilizer refers to a fertilizer that contains the three elements of nitrogen, phosphoric acid, and potassium by blending these ingredients. Compound fertilizers are used after being granulated to suit handling and application. In the above-mentioned fertilizer raw materials, components having a caking effect, such as urea and superphosphate lime, are often used as they are as granulation binders. However, these granules using the fertilizer components themselves as a binder have the disadvantage that they dissolve when exposed to rain after fertilization and are rapidly washed away. On the other hand, granulated fertilizers using synthetic polymers as a binder generally lack biodegradability of the binder, so they accumulate in soil and have an undesirable effect on plant growth and soil physical properties. As a result of various studies, the present inventor has discovered that by adding microfibrillated cellulose (hereinafter referred to as MFC) as a granulated binder to a compound fertilizer that itself has a certain degree of binding property,
It was found that a good granulated product could be obtained. Microfibrillated cellulose (MFC) as used in the present invention is a slurry of pulp fibers,
- Obtained by beating the method shown in the specification of No. 100801, the pulp fibers are beaten into a viscous form and become microfibrillated, increasing the surface area and making the entire suspension in an aqueous medium paste-like. Alternatively, it is in the form of a slurry, and is defined as "microfibrous cellulose" in the same specification. Since MFC is usually produced as an aqueous suspension with a solid content concentration of 1 to 5%, this MFC suspension can be added to the composite fertilizer raw material powder, kneaded, and granulated. The amount of MFC used in the present invention varies depending on the composition of the fertilizer to be granulated, but in so-called advanced chemical fertilizers that use urea, the amount of MFC added is 5% by weight or more in terms of solid content of MFC based on the fertilizer components. A suitable content is 30% by weight or less. That is, in order to provide sufficient hardness and water resistance, it is preferable to add 5% by weight or more, but if it is 30% by weight or more, particles with less fertilizer components will be produced, which is uneconomical. Generally, fertilizers containing urea are sticky and difficult to dry because urea has a low melting point, but MFC
The workability of drying and granulation improves with the addition of . Furthermore, the hygroscopicity of the granulated product produced by the method of the present invention is significantly improved. Furthermore, MFC has no adverse effects on the soil after fertilization and is highly biodegradable, so it does not accumulate in the soil and have no adverse effects on plants.
Examples are shown below. Example: Mix 300g of urea, 300g of potassium chloride, and 400g of ammonium phosphate, and prepare a solid content of 2% and 4%.
Add the MFC suspension and mix with a vertical mixing stirrer;
While continuing to stir, the mixture was granulated while being dried by blowing hot air at 105°C. The product was sieved, and particles that passed through 5 meshes and did not pass through 20 meshes were used as a product. In addition, this product was placed in a ball mill containing porcelain balls, and after being subjected to vibration for 15 hours, the weight of the particles pulverized to 20 meshes or less was measured. Table 1 shows the manufacturing conditions, product yield, and particle disintegration test results. 【table】

Claims (1)

[Claims] 1. A fertilizer granulation method characterized by adding microfibrillated cellulose and water to fertilizer raw material powder, kneading it, granulating it, and drying it.