DD154329A1 - PROCESS FOR THE CHEMICAL FIXING OF GRANALIA - Google Patents

Abstract

The invention relates to a process for the chemical solidification of granules. It is achieved a particularly gentle granulation, with hydratisierfaehige materials are used among others as Granulierhilfsmittel. The granules obtained can preferably be used as Duengemittel.

Description

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a> Title of the Invention - Hall, 31 · 1ο.8ο

Process for the chemical solidification of granules

b) applicati ngsgebiet the invention

The invention relates to a process for producing granules by adding finely ground kieserite, preferably for phosphorus-based fertilizer granules. The process is used for the production of technical granules from fine-grained materials, for the drying of which thermal processes have hitherto been required. Therefore, the process is particularly suitable for temperature-sensitive granules.

c) Characteristic of the known technical solutions

It is known that the granules preformed on plates or in drums of fine-grained starting materials for drying and curing are subjected to a partially complex thermal treatment. Drying at ambient temperature leads, if at all, to sufficient strength in granules only after very long drying times.

For the production of phosphate fertilizers, for example, energy and material intensive processes must be used. "The liberated in the digestion processes gases such as hydrogen fluoride and sulfur dioxide require special efforts to eliminate them ·

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d) Z ₁ JeI _{1 of the} invention

The aim of the invention is a process for the economic production of granules and the improvement of the utility properties.

The invention has for its object to solve the production of granules with little or no low thermal drying, preferably for Phosphoritbasis phosphate fertilizers to improve the fertilizing effect and to prevent leakage of polluting gases ·

e) Presentation of the nature of the invention

According to the invention, the object is achieved in that finely ground materials, preferably phosphorite, and hydratable fine-grained materials, preferably kieserite, after co-granulation using V / asser or aqueous solutions as Granulierhilfsmittel at ambient temperature solidify to hard transportable and storable granules Hydratierungsbestreben the hydratable materials are also exploited as Granulierhilfsmittel to chemically bind the remaining water in the granules · The pimple-created large surfaces "accelerate temporal hydration · The finely ground material, preferably phosphorite, is enclosed by the hydrating material, so that Hardening and increasing the pressure resistance of the granules is achieved at the same time as drying ". An acceleration of the hardening process can be achieved by means of low thermal drying s "

When using water-soluble hydratable ma-. terial, the granules easily disintegrate upon exposure to moisture, whereby the water-soluble portion dissolves · The original grain fineness of the non-water-soluble portion is obtained · Therefore, the granules are excellent as fertilizer ·

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The fluorine contained in the phosphorites is not released into the environment as fluorine hydrogen, since there is no heat effect. Likewise, no cleavage of the sulfate into sulfur dioxide occurs.

The hardness of the granules depends in particular on the proportion of the hydratable materials added and their particle size. The rate of disintegration of the granules upon exposure to soil moisture when used as fertilizer is also dependent.

f) From Guide e g beis pie 1

Phosphorite and kieserite are mixed in a ratio of 1 × 0.75 and ground in commercially available spring-roller air-flow mills to a particle size of <0.1 mm. The granulation takes place with added water of about 11% and can take place on a plate The granules leaving the plate and having a preferred particle size of 2 - 5 mm are stored in boxes for about 6 hours in order to obtain a basic strength and, after classification, are fed to the bearing for complete hardening. They .. stay there for about 3o hours in order to obtain the final hardness and compressive strength *

The granules produced according to the invention have a compressive strength of 35 1 / granular and an abrasion resistance of> 95 % . The citric acid solubility of? 2 ^ 5 is 78 %.

The grain composition of the grain is:

2 - 2.5 mm 35 %

2,5 - 4 mm 55 %

4 - 5 mm Io%

2 · Phosphorite and technical potassium chloride (K 4o) are mixed in a ratio of 1: 1 and ground in commercially available spring-roller air mills to a particle size of <0.1 mm and with 3o % (by weight) also to <0.1 mm • particle size milled anhydrous sodium sulfate mixed ·

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This mixture is granulated with addition of water of about 12 % and carried out on a plate. The granules leaving the plate with a preferred particle size of 2-5 mm are passed through a drying drum at 150 ° C. for accelerated hardening and classified. The granules produced according to the invention have a compressive strength of> 50 N / granularity and an abrasion resistance of> 95 % . The citric acid solubility of P2 ⁽ - ^> 5 is 84%

The grain composition of the grain is:

2 - 2.5 mm 36 %

2,5 - 4 mm 54 %

4 - 5 mm Io %

3 · Ground alkaline sintered phosphate and ground kieserite of <0.1 mm are mixed in a ratio of 1: 1 and granulated on a plate under approx. 13. % water addition. The granules leaving the plate with a preferred particle size of 2-5 mm are placed in boxes approx. Stored for 6 h in order to obtain a basic strength. · After subsequent classification, complete curing takes place after about 3o hours in the bearing.

The granules produced according to the invention have a compressive strength of> 20 N / granule and an abrasion resistance of> 95 % .

The grain composition of the grain is:

2 - 2.5 mm 33%

2,5 - 4 mm 58.%

4 - 5 mm 9 %

Claims (5)

- 5 - 225262. Claim for Process for the chemical solidification of granules, characterized in that finely ground materials, preferably <0.1 mm, are mixed prior to granulation by the addition of preferably 20-70 % of finely ground, preferably <0.1 mm, hydratable materials and used together granulated and solidified by water or aqueous solutions as granulating aids 2 "Process for the chemical solidification of granules according to item 1 characterized in that the chemical hardening of the granules causes an increase in the compressive strength" Process for the chemical solidification of granules according to items 1 and 2, characterized in that the granules readily decompose into their constituents in water or under the action of soil moisture, and the original granularity of water-soluble materials is restored. Process for the chemical solidification of granules according to items 1 to 3, characterized in that prepared granules of finely ground fertilizers have the same or an improved plant availability as in the original state. Process for the chemical solidification of granules according to items 1 to 3, characterized in that it granules . lation of fine-grained temperature-sensitive materials.