LT3467B - Granulate of carbamyde - Google Patents

Abstract

Carbamate granulate has a powder layer, offering protection from agglomeration. The powder layer consists of 0.01-0.6 % weight of melamine, counting for a total granulate weight.

Description

The invention relates to a urea granulate having a layer of melamine powder which prevents agglomeration.

Most granular or crystalline industrial products, including urea, tend to agglomerate over extended periods of storage or transport. This property, as a rule, has a negative impact on their quality, storage capacity, bulk, pellet durability and so on.

To protect these products from agglomeration, they are powder coated. Lime, kieselguhr, talc, clay and similar materials may be used in the powder. In addition, from the description of the present invention, for the non-accepted application of VFR patent no. No. 2039599 follows that urea mixed with biuret is less prone to agglomeration. However, large amounts of these agglomeration reducing agents need to be added to achieve sufficient activity.

In addition, U.S. Pat. No. 3837835 describes the treatment of granular materials, such as ammonium nitrate-based fertilizers, with S-triazines substituted with longer alkyl radicals or ether groups. However, such substituted S-triazines are relatively complex compounds which further impede the further conversion of urea granulate into melamine.

It has recently been unexpectedly discovered that the agglomeration of urea granulate can be substantially reduced by mixing melamine powder into the urea granulate.

Therefore, the present invention relates to an urea granulate having an anti-agglomeration melamine powder coating, characterized in that the powder coating comprises 0.01-0.6% by weight of melamine based on the total weight of the urea granulate.

In this case, melamine can be used in the form of a purified product for sale. It is also possible to use impure melamine from the melamine synthesis process, the so-called filtrate melamine, since minor impurities such as amelin or amelide have no deleterious effect upon further processing of the urea granulate into melamine, since these impurities are converted to a significant proportion in the melamine process. melamine.

The use of urea granules coated with filtrate melamine, for example in the fertilizer or compound feed industry, also causes no problems due to the low level of impurities.

The melamine powder is mixed with the urea granulate in powders, vibrating troughs or other suitable equipment at room temperature. In order to facilitate distribution on the urea granulate and to achieve uniform and, as far as possible, effective operation, use, wherever possible, the smallest amount of additive, uses melamine, with as much dispersion as possible. In this case, the duration of the mixing process depends on the choice of mixing apparatus and the desired capacity. In this case, the melamine content is 0.01-0.6% by weight, preferably about 0.02-0.4% by weight based on the total weight of the urea granulate.

The reduction in urea agi omerization due to melamine impurities is determined by the shear force according to Jenike (e.g., Chem. Technologie, Winneker, Kuechler,

4th Edition, Volume I, page 120). In this case, the samples, depending on the circumstances, at room temperature for 23 hours. the rail is depressed by a piston having an area

22.9 sq. Cm and a diameter of 5.4 cm respectively. Creating

15.5 N / sq. cm pressure.

Tests carried out have shown that, after the addition of 0.1% by weight, respectively, 0.035% by weight of pure melamine or

With 0.1% by weight of melamine leachate, the shear force can be reduced by up to 50% and more, whereas in the case of powder described in the literature, such as burette, much larger amounts, about 5%, need to be added to achieve the same performance.

Example:

1000 g urea granulate containing 0.26% water (Karl Fischer method) with a laboratory mixer for 15 min. mixed with 1 g (0.1 wt%), respectively, 2 g (0.2 wt%) of melamine containing 0.13%

5 of water.

The addition of 0.1% melamine reduces the shear force from

43.7 N to 22 N (semi). The addition of 0.2% melamine reduces the cutting force to 16.8 N.

An example

1000 g of urea granulate containing 0.25% water,

in my laboratory in a blender bag 15 mins on the track WITH 1 g '7 ± z_. (0, 1 % by weight) melamine leachate, containing 1.3 oh, o there is - dens. Cutting force in this case decreases from 24th -i t t- N

to 14.0 N.

Example 3 0

37.500 g urea granulate containing 0.30% water in a concrete mixer for 15 min. is blended with melamine containing 0.06% water. Addition of 13 g (0.035% by weight) of melamine to urea granulate reduces the shear force from 52.2 N to 22.5 N, i.e. more than half.

BAD ORIG1NAL

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Example: Example of comparison

1000 g urea granulate containing 0.26% water in a laboratory mixer for 15 min. over the bag with

Burette for analysis by Merck, containing 2.92% water. Only with the addition of 53 g (5 wt%) of burette succeeded in reducing the cutting force by about half, i.e. from 50 N to 29 N.

Claims (4)

DEFINITION OF INVENTION 1. Urea granulate, containing a powder coating, non-agglomerating 5, wherein the powder coating comprises 0.01-0.6% by weight of melamine based on the total weight of the urea granulate. Urea granulate according to claim 1, characterized in that the powder layer comprises 0, ΟΣΟ, A% by weight of melamine based on the total weight of the urea granulate. Urea granulate according to claim 1, characterized in that the powder layer consists of an impure melamine formed by the process of melamine synthesis. Use of urea granulate according to claim 1 for the synthesis of me20 laminate.