DE2644522A1 - FERTILIZERS WITH A REDUCED TREND FOR CAKING AND METHOD FOR MANUFACTURING IT - Google Patents

Description

DR. BERG DiPL.-NG. STAPF DIPL.-ING. SCHWABE DR. DR. SANDMAIS.

PATENT LAWYERS

8 MUNICH 86, POST BOX 8602 45

Dr. Berg Dipl.-Ing. Stapfund Partner, 8 Munich 86, PO Box 860245

Our reference 2J 4 80 8 MÜNCHEN 80 October 1st, 1976

Our ref. Mauerkircherstraße 45

Lawyer file number: 27 480

EXXON RESEARCH & ENGINEERING COMPANY Linden, New Jersey / USA

Reduced caking fertilizers and processes for their manufacture

The present invention relates to anti-caking preparations for use in fertilizers to reduce the tendency of the fertilizer particles to agglomerate and become large bulky during storage To form lumps.

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(089) 98 82 72 Telegrams: BERGSTAPFPATENT Munich Banks: Bayerische Vereinsbank Munich 453100

987043 TELEX: 0524560 BERGd Hypo-Bank Munich 3892623

983310 Postscheck Munich 65343-808

7Ö9815 / 088?

It is known that fertilizer flakes during storage tend to agglomerate and form lumps which can become extremely large in large-scale storage. It has been disclosed, for example, in US Pat. No. 2,772,833 and British Patent 755 516 suggested this Problem to be solved by spraying the fertilizer granules with an aqueous solution of an alkylary sulfonate. Even though however, this reduced the tendency of the fertilizers to cake together, since the presence of water the As the main cause of caking, the use of an aqueous solution is not entirely satisfactory. It it has also been suggested to treat the granules with a hydrophobic liquid such as a hydrocarbon oil, to be coated, and it was because the compatibility of the hydrocarbon oil with the normally aqueous surface of the granules is also important, also proposed, for example in Belgian patent 563 338, fatty acids or fatty amines to improve tolerability to incorporate the liquid with the granules into the hydrophobic liquid. However, this mode of operation has the The disadvantage is that the fatty acids have a low level of caking have a preventive activity, while the fatty amines in hydrophobic liquids at room temperature have a limited Show solubility, so that it is generally necessary to store the solutions at elevated temperatures, what

itself is costly. In addition, the solutions of the pettamine must be applied at temperatures which are higher than the storage temperatures of the fertilizer , which incurs additional costs.

It has now been found that a hydrophobic liquid that an alkyl aryl sulfonate derived from an alkyl aryl sulfonic acid with a molecular weight greater than 400, contains a particularly useful anti-caking agent especially at the normal temperatures used for storing fertilizers.

Therefore, the present invention provides a caking-reducing composition containing a hydrophobic liquid, at least 0.01 wt -.% ₃ and preferably from 0.01 to 20 wt -. Containing dissolved% einesAlkylarylsulfonates that of an alkylarylsulfonic acid having a molecular weight of greater than 400.

The present invention also provides a process for reducing the tendency for fertilizers to cake together, in which fertilizer granules are mixed with a solution containing at least 0.01% by weight , and preferably from 0.01 to 20% by weight , of an alkylarylsulfonate which is derived from an alkylarylsulfonic acid with a molecular weight greater than 400,

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contains in a hydrophobic solvent, coated.

The invention further provides granular fertilizers coated with a caking-reducing preparation which includes a hydrophobic liquid which, dissolved therein, has at least 0.01% by weight, and preferably from 0.01 to 20% by weight , of an alkylarylsulfonate, derived from an alkylarylsulfonic acid having a molecular weight greater than 400.

In order to reduce the tendency of the fertilizer granulate to cake together, the fertilizer granules are coated with a das Caking-reducing preparation is sprayed after drying and it becomes caking-reducing • Preparation most conveniently sprayed onto the dried granules at the end of the manufacturing process, in particular when the granules are in a rotating drum, which helps to provide an even coating. The ways of working of the present invention are particularly useful for reducing the tendency for nitrogenous compounds to cake together Fertilizers, especially the complex calcium ammonium nitrate -, N.P.K. and ammonium nitrate fertilizers useful. These materials are highly hydrophilic and tend to cake when moist, and so do it it is believed that this caking tendency is caused by

the anti-caking preparation is reduced j which acts as a waterproof layer for the granules. It is therefore preferred that the caking reducing preparation be used in the fertilizer manufacturing process is applied shortly after the drying stage.

The hydrophobic liquid of the preparation according to the invention therefore acts as a waterproof layer and the presence of sulfonate increases the tolerance of the liquid with the surface of the fertilizer granules both when applying the preparation and under the conditions under which the fertilizer is stored.

The selection of the hydrophobic liquid used in the inventive Preparations used depends on the character of the surface of the fertilizer grains and the Process by which the preparation is applied to the fertilizer. It can be any suitable liquid with a flash point high enough to ensure that there is no fire hazard. Examples of hydrophobic liquids include both paraffinic and naphthenic mineral oils, and as well also synthetic liquids, such as synthetic isoparaffins, esters or synthetic or natural ones Acids or polyacids with synthetic or natural

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Alcohols or poly oils. According to the present invention it is preferred to use a mineral oil and where the preparation is sprayed onto the fertilizer preferably an oil with a suitable viscosity at the spray temperature is used. Many conventional sprayers operate at temperatures of about 70 ° C, and in these cases it is preferred to use a mineral oil with a viscosity to be used in the range from 5 to 20, preferably in the range from 10 to 15 centistokes at the spray temperature.

The alkyl aryl sulfonate used in the formulations of the present invention must be in the hydrophobic liquid be soluble, and it. it has been found that alkylarylsulfonates which are derived from alkylarylsulfonic acids with a molecular weight of greater than 400 should be used. In particular, it is preferred to use sulfonates derived from Alkylarylsulfonic acids with a molecular weight of greater than 460, in particular of such acids with a molecular weight in the range 480 to 530. The sulfonates used can be a mixture of sulfonates, that of sulfonic acid with various molecular weights descend. In such a case, the molecular weight should be understood to mean the average molecular weight of the sulfonic acids from which the sulfonates are derived. The SuIfonat may or may be an alkali or alkaline earth metal sulfonate

the sulfonate of a nitrogen-containing compound, such as ammonia, fithanolamine, ethoxyamines or Be fatty acid amines.

The amount of sulfonate or sulfonate mixture that should be employed is not critical provided that it is sufficient to ensure compatibility of the hydrophobic liquid with the surface of the fertilizer granules and that this remains so during storage of the fertilizer. It has been found that the preparation of at least 0.01 percent - should contain% of sulfonate, and used from an economic point out as little as possible of it.. It has been found that preparations with a content of 0.01 to 20 %, preferably 0.5 to 15 % , in particular 1 to 15 % _{3 are} particularly suitable. The amount of preparation that should be applied to the fertilizer depends on the chemical nature and morphology of the fertilizer. However, it was found that good caking reducing properties can be achieved when from 0.005 to 0.4 wt .- # -.% Of the formulation, based on the weight of the fertilizer, is used.

The preparations of the present invention, in addition to the sulfonates, may contain other caking-reducing agents.

de funds included. The need for any special, caking reducing agent depends on the nature of the fertilizer from, but was found ₃ that a preparation according to the invention, which also contains a Pettamin a particularly effective, is the caking reducing agent, especially with calcium ammonium nitrate fertilizers. It has been found that a solution of an ethanolamine sulfonate and a fatty amine is particularly useful. It has also been found that the fatty amines, which heretofore required special heating when used as anti-caking agents, can be used without the need for such special heating, since the presence of the sulfonate appears to aid the solubility of the amine. Any suitable fatty amine, which may be saturated or unsaturated, can be used and it is preferred that it contain at least 12 carbon atoms. Most of the commercially available fatty amines are mixtures of amines and those containing predominantly amines of 16 and 18 carbon atoms have been found to be particularly useful. It was further found that formulations having a content of 0.1 to 10 wt .-%, preferably from 1 to 4 wt -.% Are particularly useful in the preparation of amine. It can also contain fatty acids or take the place of the fatty amine, but such preparations are less effective.

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It is known to use fertilizers with powders such as chalk or diatomaceous earth to reduce their tendency to treat for caking. The preparations of the present invention can be used in combination with a powder treatment and this is the preferred method with NPK fertilizers. The powder and the invention Preparations can be applied to the fertilizer simultaneously or sequentially, but itfurde found that with NPK fertilizers particularly good results were obtained when the fertilizer was first mixed with the powder and then treated with the preparation according to the invention.

The formulations of the present invention can be used with most types of fertilizers, and the drier the fertilizer, the better they work. It is therefore preferred that the fertilizer less than 0.4 wt -.% _S especially preferably less than 0.35 wt .- ^ water containing the preparations of the invention are therefore preferably shortly after the drying step in the production process of the fertilizer applied. The preparations are particularly useful for nitrogenous fertilizers, such as calcium ammonium nitrate, where it is preferred to use a preparation that also contains a fatty amine, and for NPK fertilizers, where it is preferred

70981 S / 0887

it is allowed to first treat the fertilizer with a powder.

The present invention will now be explained in more detail in the following examples, which, however, are not intended to restrict them
explains in which the degree of caking of the fertilizer is measured with the "caking number", the
is a number that indicates the force that leads to
Breaking up the fertilizer is required. In the experiment, the fertilizer is applied under a standard pressure of
40 kg per cm were stored in a cut cylinder for 24 hours and the force required to separate the
two parts of the cylinder is required and according to the
following formula

Separation force (in g)
_n p ^

converted to obtain the caking number of the fertilizer. Shows a caking number less than 20 satisfactory caking-reducing behavior however, a caking number less than 10 is preferred.

example 1
17 wt -.% Of the sodium salt of an alkylarylsulfonic

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26A4522

nt

Molecular weight 520 was dissolved in a paraffinic mineral oil with a viscosity of 3.55 centistokes at 100 ° C and 11.3 centistokes at 50 ° C. This solution was then dried calcium ammonium nitrate fertilizer based on a Grundrnasse containing 75 wt -..% Belgian chalk (Belgian chalk) and 25 percent · *% Welsh chalk, and containing about 26% nitrogen, 13% ammonia and 0, 34 wt .-% water 0.13 to 0.25 wt .-% water, sprayed on. .23 to 0.25 wt -.% Of the preparation were applied to the fertilizer, while it was fed through a coating drum for storage and then stored for the fertilizer. After several months of storage in piles or in sacks, there was no sign of caking.

Example 2

Various amounts of the sulfonate solution used in Example 1 were applied to the fertilizer of Example 1 and so different treatment rates from sulfonate to fertilizer achieved. Each freshly treated sample was subjected to the caking test with the following results:

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1S *

% By weight of sulfonate _solution "" OTT1Trl, ",", _Ί

of fertilizer caking-Zanl

0 between 40 and 60

0,, 2O between 12 and 17

0.25 between 9 and 14

0.30 between 4 and 10

For reasons of comparison the fertilizer with the same oil was treated, but containing no sulfonate, with treatment rates in the range of 0.2 to 0.40 wt -..% Oil, based on the fertilizer, and there was the caking-number in all cases between 20 and 30.

Example 3

The monoethanolamine salt of sulfonic acid from which the sodium sulfonate of Example 1 was derived was prepared and separately dissolved in the same oil as used in Example 1. We presented solutions 9 and 13 wt -.% Forth. These solutions were applied to the same fertilizer as in Example 1 at various treatment rates, and the caking number of the fertilizer was measured. The results are shown in FIG.

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Example 4

The procedure of Example 2 was repeated, the diethanolamine salt being used instead of the monoethanolamine salt. There were three solutions of 5 wt .-% ^ ₅ 9 wt .-%
and 13 % by weight sulfonate used. The caking number of the
Fertilizer at different treatment rates is shown in FIG.

Example 5

The sulfonate used in Example 1 was mixed with an equal amount of a 20% fatty amine solution (commercially available as Noram SH) and 200 tons of fertilizer at a treat rate of 0.2 wt -.% In the same
Way as in Example 1 applied. A caking number between 7 and 12 was obtained. After storage for β months, both in bags and in heaps, left
handle the fertilizer normally.

Example 6

The anti-caking agent of Example 1
was based on 2000 tons of a similar fertilizer as in
Example 1 applied except that the anti-caking agent was applied immediately after drying
the fertilizer was applied in the course of its manufacturing process and not only after its transport

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709815/0867

to the laboratory as in Example 1. A treatment threshold of 0.25 wt. / 2 was used to reduce caking Means related to the fertilizer applied.

The caking number of this fertilizer was less than 4 and the material settled in heaps after 6 weeks of storage and in bags after 6 months of storage easy to handle.

When, after manufacture, a sample of the fertilizer is brought to the laboratory and that reduces caking Agent was then applied, the average caking number was 8 ..

Example 7

A preparation containing the SuIfonatlösung of Example 1 and additionally 1.4 wt -.% Of a commercially available fatty amine with 30% C ₁ / - containing amines and 60% CLn amines, was applied to the same type of fertilizer used immediately in Example 1 by Completion of fertilizer production applied. It turned treat rates of 0.10 wt -.% "0.15 wt .-% and 0.20 wt -.%, Based on the fertilizer, of.

The caking index of these fertilizers was as follows:

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Treatment rate (Wt. Ji)

Caking number

0 , 10 4

O ₅ 15 about 4

0.20 4

The caking number of the untreated fertilizer was from 10 to 12.

example

Two commercially available calcium ammonium nitrate fertilizers containing 26 % nitrogen were coated with various anti-caking preparations and the caking count was measured. The results are as follows:

Caking-reducing preparation

Treatment rate wt .- # fertilizer

Sodium sulfonate from Example 1

0 0.2

Fertilizer / cake number

132
14th

41 35

Sodium sulfonate) from example 1) + 1 % pettamine)

0.1

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Caking treatment rate reducing preparation wt % fertilizer

Fertilizers / Zusammeriback-Zanl

Sodium sulfonate) from example 1 +) 2 % fatty amine)

1 % fatty amine alone

2 % fatty amine alone

Ethanolamine sulfonate from example 4) + 1 % fatty amine)

Ethanolamine sulfonate from example 4) + 2 % pettamine)

Example 9

An ammonium nitrate fertilizer with a content of 36% by weight nitrogen, which had a caking number of 32 untreated, was treated with the ethanolamine sulfonate solution of Example 4 with a content of 1 % pettamine at a treatment rate of 0.1% by weight. - ^, based on the fertilizer, treated.

The caking number of the treated material was found to be 4 certainly.

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example

An NPK fertilizer containing 17 wt% nitrogen , 2 wt% phosphorus and 27 wt% potassium was subjected to the various treatments summarized below, ₃ and the caking number of each sample measured.

Zus ammenb ack number

Fertilizer + 1 wt. ~% Of diatomaceous earth

Fertilizer + 1 wt .- ^ diatomaceous earth)

+ 0.2 % by weight sodium sulfonate solution)

from example 1 (consecutive)

Treatment) )

Fertilizer + 0 ^ 2 wt -.% Natriumsul-)

fonat solution from example 1+)

1 wt -.% Of diatomaceous earth (nacheinander-)

following treatment))

Fertilizer + 0-2 wt .- ^ sodium sulfate)

fonat solution and 1 wt. % diatoms-)

earth (simultaneous treatment))

Fertilizer +0.2 wt -.% Natriumsul-) ^ ₂

fonat solution from example 1)

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Caking number

Fertilizer + 0.2 wt -.% Hatriumsul-) sulfonate solution of Example 1 with a) content of 1.4 wt -.% Of a fatty amine)

It should be noted that there is a considerable difference in the properties within a bulk stored fertilizer and from one batch to another of those produced Fertilizer is present in the same way as in particular in the morphology and water content of the fertilizer. Hence, those are given for the cake number Values average values and the purpose of the values given is to show the trend obtained when the various caking-reducing preparations are used.

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Claims (1)

Claims / lj A method for reducing the tendency of fertilizers to stick together by coating the fertilizer granules with a caking-reducing preparation, characterized in that the caking-reducing preparation contains a hydrophobic liquid which is at least 0.01% by weight ₃ and preferably 0 01 to 20 wt -.% of a Alkylarylsulfonates that of an alkylarylsulfonic acid having a molecular weight of greater than ¹ JOO derived, contains dissolved. 2. The method according to claim 1, characterized in that the sulfonate is the sulfonate a nitrogen-containing compound selected from ammonia, ethanolamine, ethoxyamines and fatty acid amines, is. 3. The method according to any one of claims 1 and 2, characterized in that the caking reducing preparation also contains a fatty amine. 4. The method according to any one of claims 1 to 3 » characterized in that the fertilizer with an amount in the range of 0.005 wt .- ^ to 0.4 wt! - 20 - 709816/0867 on which the caking-reducing preparation is coated. 5ο Method according to one of claims 1 to 4, characterized in that the fertilizer is also coated with a caking-reducing powder., β ο method of claim 5 wherein _S j that the powder is applied to the fertilizer prior to the application of the caking-reducing formulation. 7- fertilizer granules, characterized s that they have been prepared by a process according to any one of claims 1 to. 6 8 = NPK Düngernittel granules, characterized s that they carry a first coating of a caking reducing powder and a second coating of a hydrophobic liquid, in which at least 0 _s 01 wt <-. $, And preferably 0, 01-20 wt - $ a Älkylarylsulfonats _s are derived from an alkyl aryl sulfonic acid having a molecular weight greater than 400 dissolved j " - 21 - 2844522 9. Calcium ammonium nitrate granules, characterized in that they have a coating of a hydrophobic liquid in which at least 0.01% by weight , and preferably from 0.01 to 20% by weight , of an alkylarylsulfonate which is derived from an alkylarylsulfonic acid a molecular weight of greater than 400, and a Fettami η are dissolved. 709815/0867