JPS5858312B2 - HIGH SHIKIRIYUJIYOHIRIYO NO SEIZOU HOUHOU - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a compound granular fertilizer, and more particularly to an improvement in a method for granulating a compound granular fertilizer containing ammonium phosphorus.

Compounding type granular product in which various fertilizer components are crushed and blended, granulated by spraying water using a drum-type or dish-type granulator, then dried in a dryer such as a rotating drum, and then sieved to produce a product. Compared to so-called chemical fertilizers, in which fertilizer components are mixed and granulated in a slurry, fertilizers can be produced simply and with small-scale equipment, and are therefore advantageous for producing a wide variety of fertilizers in small quantities.

However, the compounded granular fertilizer has the disadvantage that the hardness of the granulated product is low, so that it becomes powdery during drying.

In particular, in the case of a compound granular fertilizer containing urea, granulation becomes difficult, and furthermore, when the urea content exceeds 10% by weight, granulation becomes virtually impossible.

For this reason, the urea content of compounded granular fertilizers has been limited to 10% by weight or less.

Conventionally, various granulating agents have been developed to successfully granulate such fertilizers, but no granulating agent has been found to be sufficiently effective.

In view of the above-mentioned circumstances, the inventors of the present invention have conducted intensive studies to provide a granulating agent for a combination granular fertilizer that exhibits an excellent aggregation effect and can produce a granular fertilizer with extremely high product hardness. The present invention was completed based on the finding that this has a grain promoting effect.

That is, the gist of the present invention resides in a method for producing a combination type granular fertilizer, which comprises granulating a fertilizer component mixture containing phosphorous ammonium in the presence of a water-soluble iron salt.

To explain the present invention in detail, the raw material composition of the compound granular fertilizer targeted by the present invention may be any composition as long as it contains ammonium phosphorus, such as ammonium phosphorus, urea, potassium chloride, and potassium nitrate. , and compound fertilizers mainly containing potassium compounds such as potassium sulfate.

In addition to these fertilizers, ammonium sulfate or other fertilizer components may be added as appropriate.

Although the amount of each fertilizer component may be determined as appropriate, in the present invention, good granulation can be achieved even if the urea content is 10 to 30% by weight.

Next, the water-soluble iron salt that is the granulating agent of the present invention includes one or more of iron sulfate, iron nitrate, iron chloride, etc., and ferrous sulfate is particularly preferred.

Commercially available products are usually used as these iron salts.

If the amount added is too small, the effect of promoting granulation will not be exhibited, so it is used at least 1% by weight, preferably at least 2% by weight, based on the granulated material.
Since the ratio of the components decreases and an insoluble gel-like substance is formed, it is usually used in an amount of 2 to 3% by weight based on the weight of the dough.

The method of adding the water-soluble iron salt is not particularly limited, and may be carried out by directly blending it into the raw materials or by dissolving it in water and spraying it as granulation water.

. Although the granulation promoting effect of water-soluble iron salts is not clear, the water-soluble iron component reacts with the phosphoric acid contained in ammonium phosphorus to form FeNH4H2(PO4) 2 ・'A H20 or FeNH4HF2PO, etc. It is thought that a substance is formed, and the substance imparts viscosity to the particles and has the effect of promoting granulation.

Since the above substances are soluble in Petermann's solution (2% citric acid solution), there is no loss of phosphoric acid as a fertilizer component.

According to the method of the present invention, it is possible to easily produce a compound granular fertilizer with a high urea content, which has not been possible in the past, by using a simple method of using water-soluble iron salt as a granulating agent in the conventional method of granulating a compound granular fertilizer. has the advantage of being obtainable in high yield.

Furthermore, the water-soluble iron salt used as a granulating agent is not only harmless to agricultural crops, but also helps retain iron as a trace element in the soil.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example diameter: 285 m/m, depth: 100 m/m, inclination angle: 30
402 parts by weight of diphosphoramine (hereinafter simply referred to as "parts") was prepared using a dish-shaped granulator of

) 107 parts of ammonium sulfate, 196 parts of urea, 258 parts of potassium chloride, and ferrous sulfate (Fe2SO4.7H20) as a granulating agent.
Add 20 parts, rotation speed 5 Orpm, granulation temperature 65°C
A granulation test was conducted by spraying water under conditions where each granulation time was 5 minutes.

After granulation, the granulated product was sieved to obtain a granulated product with a particle size of 1.4 to 4.0 m/m at a yield of 70.5%.

For comparison, similar granulation tests were conducted with respect to the case where ferrous sulfate was not added and the case where 20 parts of finely ground iron ore was added as a granulating agent.

The yield of granulated products of 1.4 to 4.0 m/m is 4
2% and 40.0%, both of which were much lower than in the case of adding ferrous sulfate according to the present invention.

Claims (1)

[Claims] 1. A method for producing a combination granular fertilizer, which comprises granulating a fertilizer component mixture containing ammonium phosphorus in the presence of a water-soluble iron salt.