DE1015018B - Process for the production of granulated fertilizers - Google Patents

Description

Process for the production of granulated fertilizers It is known and it is common practice to convert fertilizer salts into a granular form in order to achieve homogenization on the one hand to achieve and to avoid a subsequent segregation and on the other hand at Use better to deal with it, e.g. B. to be able to scatter. The grains should be included be as hard and firm as possible, have a good shelf life and be comfortable let handle. To be used for the purpose and to improve the grain properties in the granulation process often binding, adhesive or solidifying substances such. B. water glass, plaster of paris, etc., added, or you can leave such substances or salts, z. B. certain phosphates, arise in the granulation process itself. In this way it is possible to get stable, firm and hard grains, which however - what in In this regard, a disadvantage of the good grain size is - when exposed to water in many cases do not resolve and disintegrate with the desired speed. So There is often some contradiction when the task is to make grain products produce that are durable, hard and as little hygroscopic as possible on the one hand, on the other hand, when exposed to moisture, they disintegrate well and quickly and their to bring soluble parts to effect. You can possibly get a faster one Achieve disintegration of the grain if you look at the materials in the grain with foreign matter (Slag, sand or the like) or an excess of soluble salts. Apart from that of the fact that the effect achieved is usually not very great, one needs for this Purpose quite substantial amounts of these additives - which is often undesirable -, or the hygroscopic properties of the products obtained and thus their storage properties deteriorate in an unacceptable manner.

It has now been shown that the disintegration of fertilizer granules when exposed to water can accelerate significantly when granulating Material carbon black is added in amounts of about 0.05 to 0.10 (o. The use of larger Amounts of soot do not in themselves have a detrimental effect. An improvement in the effect but this is not to be expected. The amounts given are sufficient to prevent the grain from falling apart accelerate very strongly when exposed to water, without affecting the rest Properties of the grains, i.e. their hardness, tendency to bake, etc., are adversely affected or the products become more hygroscopic. On the contrary, it has been shown that in many cases the resistance to deliquescence when exposed to humidity is significantly improved by adding carbon black.

Various proposals have been made to use carbonaceous fertilizers Add materials as adhesive and binding substances during granulation. The aim here is to improve the granulation itself and solidify it of the grains, and the additional amounts to be added are adapted to this. This The aim is, as it were, the opposite of the method of the invention in that in the case of the latter, the addition of soot prevents the grain breakdown under the circumstances described should accelerate.

One has also done in the manufacture of artificial fertilizers Mixing different substances soot used. Here, the soot in its property used as fertilizer, and accordingly, in this case, the proportion of the Carbon black in the end product is incomparably high compared to the amounts obtained according to the invention come into use.

The interrelationships between the addition on which the invention is based of soot in the specified order of magnitude to the fertilizer and the effects caused by it Acceleration of the grain disintegration when exposed to water was known Proceedings not before.

The economic efficiency of the process can be ensured by that the specified additives in the form of waste products, e.g. B. as water-containing Carbon black, can be used and added before or during the granulation.

If the intrinsic color of the original product is due to the coloring Addition of carbon black is changed in an undesirable way, this color change can be caused by a subsequent powdering or application of one of the usual powdering applications Medium (plaster of paris, lime, talc, kieselguhr or similar) externally covered or softened with which of course at the same time those achievable with such an aftertreatment Advantages in terms of baking tendency and hygroscopicity of the products are connected. To the Powdering can be used to achieve a uniform color of the powdered product with a mixture of the powder and carbon black or another to achieve the uniform coloring, possibly at the same time to improve the fertilizer properties, suitable inert material are carried out. In some cases it can also be useful be, on the grain material treated according to the invention directly the soot as powder material to be applied additionally.

The acceleration of grain disintegration through the addition of soot and in particular the influence of the small amounts required for this purpose is as follows Examination examples to be recognized: Example I a) For the production of a complete fertilizer 10 kg of rock phosphate were digested with 14.5 l of nitric acid and added ammoniated from 0.55 kg kieserite up to pa value 8. After precipitation of the next to the Dicalcium phosphate present as nitrate carbonated calcium was the resultant Porridge mixed with 11.2 kg 60% potassium salt, 4.5 kg gypsum and 1.7 kg potassium sulfate, granulated and dried.

b) For a complete fertilizer produced according to the same type in addition to the neutralized slurry during manufacture before adding the Potash salts and the gypsum 70 g of a 40% aqueous soot sludge were added. The amount of soot, based on the finished product, was 0.05%.

To determine the rate of disintegration of the two products were 100 g each of the material between 2 and 3 mm sieved into a glass cylinder given and covered with equal amounts of water. Then the time was determined at which the grain boundaries began to blur. The averages out of several Measurements were a) without addition 83 seconds, b) with carbon black 28 seconds.

The addition of carbon black increased the rate of disintegration very strongly. example II The complete fertilizer prepared according to Example I without additives was mixed with water slurried and a) without additives, b) with soot, c) with lignite, d) with graphite, e) granulated with peat meal and dried again. The additions were 0.05% des Finished product. The disintegration times were again according to the above method certainly. The average values for the rate of disintegration were a) 74 seconds b) 16.5 "c) 21.0" d) 18.0 e) 19.5 "Even under these conditions the great influence of soot on the rate of disintegration is unmistakable. the Numbers clearly show the influence of the additives on the rate of disintegration and that carbon black, despite the use of only half the amount, has the effect of the known additives, such as lignite, graphite, peat meal, significantly outperforms.

Claims (3)

PATENT CLAIMS: 1. Process for the production of granulated fertilizers by adding small amounts of carbonaceous materials to the products to be granulated before or during the granulating process, characterized in that the fertilizers are added with carbon black in amounts of about 0.05 to 0.1%. 2. Procedure according to Claim 1, characterized in that the obtained using carbon black granular fertilizers common powdering agents, such as plaster of paris. Lime, talc, diatomite, etc. Like., are applied. 3. The method according to claim 2, characterized in that to achieve a uniform color of the powdered product, the powdering with a mixture of the powder and carbon black or another to achieve the uniform color is optionally carried out at the same time to improve the properties of the fertilizer suitable inert material. Considered publications: German Patent Nos. 887 949, 887655, 863 947, 863 946, 857 057, 837 104, 817 455, 694 049, 634 111, 622 876, 514 253, 510 925, 86 715; Austrian Patent No. 150 279; British Patent Nos. 382,988, 235 802, 154057.