JPH0280387A - Production of compound fertilizer - Google Patents

Abstract

PURPOSE:To considerably increase the yield of granulation of compd. fertilizer and to make it possible to granulate even mixed fertilizer difficult to granulate by using a holmite mineral as a binder for granulating the compd. fertilizer. CONSTITUTION:A holmite mineral as a binder is added to powdery starting material for compd. fertilizer by 1.0-15.0wt.% and they are granulated. A synergistic effect can be produced by further adding one or more among bentonite, ligninsulfonate and CMC as bonders so as to increase the yield of granulation. Powder of a fibrous magnesium silicate hydrate-based clay mineral such as sepiolite or attapulgite is used as the holmite mineral.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to the field of manufacturing chemical fertilizers used to provide nutrients to plants or to contribute to the cultivation of plants.

[Conventional technology and its problems] Fertilizer is an essential basic material for agriculture.
Fertilizer ingredients such as phosphoric acid and potassium are mixed in various formulations depending on the purpose, so there are many types.

In addition, granulated fertilizers to prevent segregation during distribution and scattering during fertilizer application are distinguished from other fertilizers by the name chemical fertilizers.

The production method involves mixing several types of salt powder containing fertilizer components in a predetermined amount, adding and mixing a binder such as bentonite, lignin sulfonate, or carboxymethylcellulose, and spraying water. After granulation using a dish-type rotary granulator or cylindrical rotary granulator while adding water, the product is dried in a cylindrical rotary dryer, sieved to a predetermined size, and packed into bags.

Oversize and undersize that occur during sieving are returned to the raw materials and reused, but when granulating while spraying water during this flow, fertilizer components are ionized and dissolved in water. Therefore, the swelling property of bentonite, which is its binder function, is inhibited, and carboxymethylcellulose is also dissolved by ions such as NH;
K” Reacts with POr and prevents binder function without thickening.

Therefore, the current situation is that formulations that use raw materials with a faster dissolution rate are more difficult to granulate, and that production is forced with extremely low granulation yields. Because it is impossible to do so, some fertilizers are distributed as a mixed powder, and manufacturers are currently researching granulation technology and trying to overcome these problems.

[Means for solving the problem 1] The present invention uses 1.0 to 15.0% by weight of holmite-based minerals in the granulated binder of the chemical fertilizer based on the raw material powder of the chemical fertilizer. Even formulations that are extremely difficult to granulate and have low granulation yields can be easily granulated with high yields, and even formulations that were conventionally considered impossible to granulate can now be granulated. This is to understand and provide information on what will happen.

[Function] When holmite minerals have a fibrous crystal structure and are dispersed in water, they have a fiber length of 0.5 to 3.0 μm and about 1/100 of that length.
The entanglement of these fibers results in a binder with high viscosity, that is, rich in plasticity.

When 1.0 to 15.0% by weight of this formite-based mineral is added to the powder of the fertilizer raw material to be granulated and granulated while adding water, the fibers of the formite-based mineral are mixed into the wet raw material. It is well dispersed and exhibits an extremely good binder effect.

The viscosity, or plasticity, that contributes to the binder effect of the present invention is not due to swelling action like bentonite, but is due to the physical entanglement of fibers, so it is hardly affected by the chemical effects of dissolved ions. do not have.

Furthermore, unlike organic fibers such as lignin sulfonate and carboxymethyl cellulose, they do not react with dissolved ions and lose their binder function, and because they are stable inorganic fibers, they do not react with dissolved ions, such as NH
It is possible to greatly increase the yield even for materials that were extremely difficult to granulate due to the effects of POPO, and it also becomes possible to granulate materials that were considered impossible to granulate.

Furthermore, since holmite minerals have excellent drying and caking properties, the hardness of the resulting product after granulation and drying is higher than that of conventional products7, and it does not break down into powder during distribution and storage ( This will greatly contribute to the production method of chemical fertilizers, which are basic agricultural materials.

[Example 1 As raw materials for chemical fertilizer, urine ffi 12.0% by weight, ammonium sulfate 58.9% by weight, diammonium phosphate 5%
．． A mixture of 5% by weight of lime superphosphate, 11.0% by weight of lime superphosphate, 9.1% by weight of potassium chloride, and 3.5% by weight of sepiolite from Nevada, USA was placed in a cylindrical rotary granulator with a diameter of 2m and rotated. When granulation water was added thereto, a granulated product with a smooth surface and almost no ungranulated crystals was obtained. When this granulated material was dried in a cylindrical rotary dryer,
The granules could be dried without breaking or deforming.

The dried granules were spherical and had a smooth surface. The particle size distribution of this dry granule is 1.61
Those with a shape of less than 1 have i 5.91% by weight, 1.6 to 3.
80.5% by weight of 8 cranes, 3.8% by weight of 8 cranes or more
．． 6% by weight, and the 1.6 to 3.8 cranes of the product are 80.
The yield was very high at 5% by weight.

[Example 2] As a mixture of chemical fertilizer raw materials almost the same as in Example 1, 12.0% by weight of urea, 57.9% by weight of ammonium sulfate,
Diammonium phosphate 6.7% by weight, lime superphosphate 8.0% by weight, potassium chloride 9.1% by weight, bentonite 6.3%
The same operation as in Example 1 was carried out to obtain a dry granulated product. The surface of the dried granules obtained was rougher than that of Example 1, and was deformed or broken during drying and contained hemispherical shapes and fragments thereof.

The particle size distribution is less than 1.6f1 at 29.0% by weight1
．． 6-3.8N is 56.5% by weight, and 3.8fl or more is 14.5% by weight, which is 1.6-3.8% of the product.
The yield of Tsuru was 56.5% by weight, which was considerably lower than that of Example 1 using ceolide.

[Example 3] As a raw material for organic fertilizer, 13.5% by weight of urea,
Ammonium sulfate 53.0% by weight, diammonium phosphate 11.2% by weight, potassium chloride 9.0% by weight, rapeseed meal powder 3.0% by weight, steamed leather powder 2.6% by weight, steamed bone powder 1
．． 0% by weight, attapulgite from Georgia, USA 3.
8% by weight mixed, lignin sulfonate 2.9% by weight
was added together with granulation water, and the same operation as in Example 1 was performed to obtain a dry granule. The particle size distribution is less than 1.6 tl.
0.9% by weight, 1.6-4 weight 1 of the product is 65.5% by weight
, 13.6% by weight exceeded 4 tl.

[Example 4] Of the mixture of Example 3, 3.8% by weight of attapulgite was replaced with 3.8% by weight of bentonite and the same operation as in Example 113 was performed to obtain a dry granulated product, but the product was not granulated. 60% by weight of products less than 1.6 van mixed with objects and fragments broken during drying, 35% by weight of products 1.6-41m,
The yield of particles exceeding 41 m was 5% by weight, which was very low compared to Example 3 using attapulgite.

[Effect of the invention] Both Examples 1.2 and 3.4 are extremely difficult to granulate using a conventional bentonite binder, and in particular, Example 3.4 requires production at an extremely low yield. However, according to the production method according to the present invention, the yield is dramatically improved and it greatly contributes to the development of chemical fertilizer production technology.

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[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are diagrams showing the granulation yield of the product manufactured according to the present invention and the conventional product. Figure 1 Figure 2

Claims (2)

[Claims] (1) Using holmite mineral as a binder, or
It is a chemical fertilizer characterized by being granulated in combination with a binder such as bentonite, lignin sulfonate, or carboxyl methylcellulose, and the content of the formite-based mineral is in a proportion of the raw material powder of the chemical fertilizer. te1
．． A chemical fertilizer having a content of 0 to 15.0% by weight, characterized in that it is granulated by adding water to it. (2) The method for producing a chemical fertilizer according to claim (1), wherein the formite mineral is a powder of a fibrous hydrated magnesium silicate clay mineral such as sepiolite, attapulgite, or rollinite.