JPS5827980B2 - Manufacturing method of granular compound fertilizer - Google Patents

Description

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

Granular compound fertilizers are generally made by blending powdered fertilizer raw materials such as ammonium phosphorous, ammonium sulfate, potassium chloride, and urea according to various fertilizer brands, and then molding them into a drum shape in the coexistence of water and/or granulating agents such as acid, ammonia, and bentonite. It is manufactured using granulators such as granulators, dish granulators, and pug mills.

The granulated product is then dried and then sieved, and the product size particles are removed, while the sieved product is usually returned directly to the blender or granulator as a circulating quantity together with the crushed lower product.

However, in the current situation like Japan, where we have to manufacture many brands of fertilizer in small quantities, there are differences in the difficulty of granulation depending on the type of fertilizer raw material used for each brand. In addition, the moisture and temperature in the granulator, the particle size of the fertilizer raw material, the return powder after granulation, etc. must be delicately adjusted to perform granulation, making the operation extremely complicated.

In particular, nitrogen made from ammonium chloride or ammonium sulfate and potassium chloride.
When producing fertilizers based on weighted fertilizers or dissolved phosphorus fertilizers, granulation is extremely difficult, and even when water is added, sufficient granulation cannot be achieved.

Conventionally, various granulating agents have been developed to solve the operational complexity of granulating such fertilizers, but a sufficient granulating agent has not yet been found.

The present inventors conducted various studies to solve the drawbacks of conventionally produced granular compound fertilizers, and as a result, they invented the improved method described below.

According to the method of the present invention, in the production of granular composite fertilizer, it is possible to significantly improve the degree of granulation even for branded fertilizers that are particularly difficult to granulate, and/or significantly reduce the complexity of the granulation operation. can.

The method of the present invention is a method for producing a granular composite fertilizer, which comprises adding and blending methionine or a methionine salt (eg, calcium salt) to various fertilizer substances and granulating the mixture.

The granular compound fertilizer produced by the method of the present invention includes:
Depending on the combination of raw materials, a two-component system of nitrogen-weighted, nitrogen-phosphoric acid, and phosphoric acid-weighted, a three-component system of nitrogen-phosphoric acid-weighted, or a combination of magnesium, boron,
Examples include granular compound fertilizers containing elements necessary for plant growth, such as manganese.

The amount of methionine or its salt added in the method of the present invention is 1 part by weight or more, preferably 2 parts by weight or more per 100 parts by weight of the product fertilizer, and is appropriately adjusted depending on the product composition and desired particle size.

There are few restrictions on the amount added as long as it is above the above amount, but from the viewpoint of economy and granulation, generally the product fertilizer is 10
It cannot be said that it is preferable to use a large amount of 8 parts by weight or more per 0 parts by weight.

Further, the method of addition is not particularly limited, and it is carried out by charging the powder into a granulation machine together with powder raw materials blended according to various fertilizer brands and return powder after granulation.

The most distinctive feature of the method of the present invention is that in the conventional granulation method of granular compound fertilizer, methionine or its salt is used as a granulation accelerator, which is a simple method. Nitrogen-weighted fertilizers using ammonium chloride or ammonium sulfate and salt as raw materials, and granular fertilizers using molten fertilizer as main raw materials can also be easily obtained at high yields.

Regarding the granulation-promoting effect of methionine or its salt, the methionine or its salt adheres to the surface of other powdered fertilizer substances during granulation to give viscosity and increase the adhesion between fertilizer substances. It is thought that it has a grain promoting effect.

In addition, methionine or its salt used as a granulation accelerator* is used as feed itself and is not harmful to agricultural crops.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, all percentages shown in the examples are by weight unless otherwise specified.
It is.

Example A urea-based granular composite fertilizer having one ingredient was produced using a dish-type granulator with a diameter of 0.677+ and a depth of 0.1.5 m.

That is, 389 parts of ammonium sulfate (N: 21%), 290 parts of chloride weighted (K2O: 61%), and Uraform (N:
40%) and 60 parts of olivine sand were mixed with 33 parts of methionine as a granulation accelerator, and the solid mixture was heated to 70°C.

While spraying 93 parts of 98% sulfuric acid and 65 parts of water, 32 parts of ammonia gas was supplied, and granulation was carried out at a rotation speed of 24 rpm and a granulation time of 5 minutes.

*For comparison, granulation was carried out in the same manner in the case where methionine was not added and in the case where 33 parts of bentonite was added as a granulation accelerator.

The particle size and hardness of the granulated products obtained by the method of the present invention and the method of the comparative example are as shown in Table 1. It was recognized that significant improvements could be made.

Example 2 A urea-based granular composite fertilizer having the following components was produced in the same manner as described in Example 1.

N N P2O5 K20 (%) 2010 12 12 218 parts of ammonium sulfate (N: 21%), chloride weight (
K2O: 61%) 208 parts, urea (uN: 46%) 21
7 parts and 21 parts of olivine sand are mixed with 33 parts of methionine as a granulation accelerator, and after heating this solid mixture to 70'C, wet phosphoric acid (P2O
Phosphoric ammonium slurry obtained by supplying 46 parts of ammonia gas to 332 parts of 5:38% H25O41%) was added and mixed to the above solid mixture, and 30 parts of ammonia gas was supplied while spraying 45 parts of 98% sulfuric acid. The pellets were granulated at a rotation speed of 24 rpm and a granulation time of 5 minutes.

For comparison, granulation was carried out in the same manner in the case where methionine was not added and in the case where 33 parts of bentonite was added as a granulation accelerator.

The binding is shown in Table 2.

Claims (1)

[Claims] 1. A method for producing a granular compound fertilizer, which comprises adding methionine or methionine salt as a granulation accelerator to various fertilizer substances and granulating the mixture.