RU2226124C2 - Method of granular multi-component fertilizer production - Google Patents

Abstract

FIELD: agricultural chemical fertilizer production, particularly obtaining of multicomponent fertilizer granules from granules of initial fertilizers. SUBSTANCE: method involves compacting mixture of granules by press rollers into pressing-and-granulating machine, extruding compacted mixture through drawing nozzles of pressing-and-granulating machine. EFFECT: possibility of particularly multi-component fertilizer granules obtaining without preliminary grinding of initial fertilizers, without use of additional binders and without heating thereof. 2 dwg

Description

The invention relates to the production of mineral fertilizers for agriculture and can be used to obtain granules of multicomponent fertilizers from finished granules of the original fertilizer.

To obtain the highest yield, it is effective to use mineral granular fertilizer, the composition of the granules of which is best suited for these agronomic conditions. However, it is not profitable to produce multicomponent fertilizers for individual fields in large plants where fertilizers are produced. It is necessary to produce such fertilizers closer to the consumer. Therefore, for the manufacture of granular fertilizer with a multicomponent composition for specific agronomic conditions, technologies using simple and efficient equipment are necessary. It is best if this equipment is already mass-produced.

The following methods are known for producing granular multicomponent (complex) fertilizers.

In the known method for producing granular fertilizers [1], granular components of phosphorus and potassium fertilizers are mixed with carbamide, the resulting mixture is heated to a temperature of 100-140 ° C, and then the granules obtained are cooled at a speed of 30-50 deg / min. This method requires special equipment and is quite energy intensive.

Two other similar technical solutions are known [2, 3]. Application [2] describes a method in which a multicomponent fertilizer granule is obtained by compaction, for example by extrusion. Various substances in the resulting granule are spatially separated and are axially layered on each other and interconnected strips, ribbons or bundles.

In accordance with the invention according to the application [3], a multicomponent granule is obtained from an initially extruded granule with V-grooves made of primary powder material. A layer of the second material is introduced into the grooves. This method is quite complicated and requires special equipment. In addition, the starting material for the production of multicomponent granules are powder materials. This means that before molding the granules of multicomponent fertilizers, the feedstock, supplied, as a rule, in the form of granular one-component fertilizers, will have to be crushed to a powder state.

So, for example, in the known construction [4], granulation is made from granular material by rolling granules of material to be pressed by press rolls, which is fed to the inner surface of a perforated cylindrical drum.

In the design [5], when granulating, conical-shaped rolls are rolled along a flat matrix with dies and the source loose material is pressed through openings of the dies. A similar method is described in the application [6], where cylindrical rolls move along a flat matrix.

Known designs in which the pressing of the material is carried out in two stages, for example, the design described in the application [7]. Each granulation stage of this design contains a flat disk with many holes-dies, on the surface of which a roll pressed against it rolls. All rolls of two stages are connected by a common vertical shaft passing through the disks. In this granulator, the friable feed material is first, in the first stage, pre-pressed, and then finally pressed in the second stage.

The granulation method implemented in this two-stage design does not fundamentally differ from the method that is implemented in the mentioned single-stage design [5, 6]. The original loose material is also used, in the first stage it is primary pressed, in the second - final.

A similar method of two-stage granulation is implemented in the design [8]. In this design, the conical press rolls are rolled on a flat matrix with holes. Two matrices are located one above the other. The through holes of the upper matrix for loose pelletized strands of completely crushed material have a larger diameter than the through holes of the lower matrix. At the first stage, preliminary compaction of the initial ground material occurs, at the second stage, final granulation occurs.

The most productive and massive way to obtain granules of mineral fertilizers is considered to be the rolling of the original powder mass in devices containing rolls and a die with dies [9]. This method is adopted as the closest analogue of the prototype.

Complex, multicomponent fertilizers in the form of granules are obtained in this way only from a powder mass of mixed composition. Therefore, if the feedstock is supplied in the form of separate granular fertilizers, the preliminary operation of grinding granules is first carried out, which requires additional equipment and additional energy costs.

However, the considered methods for producing granular multicomponent fertilizers do not meet the task.

The technical problem to be solved by the claimed invention is directed is the production of multicomponent fertilizer granules directly from a mixture of granules of various fertilizers, without prior grinding. The solution to this problem using well-known, widespread and productive equipment is an important, cost-effective result.

The essence of the claimed invention lies in the fact that to obtain a granular multicomponent fertilizer, granules of two or more fertilizers are mixed and granulation is carried out by extrusion of the obtained mixture of granules through dies of a press granulator containing rolls and a matrix with dies.

The granulator press may comprise a cylindrical matrix with die holes, inside of which there are press rolls pressed against the inner surface of the matrix. Press rolls or the cylindrical matrix itself can rotate.

In another embodiment of the method, the pellet mill may comprise a planar die along which cylindrical or conical rolls are rolled.

When implementing the proposed method does not require preliminary grinding of granules. The original granules of individual fertilizers, mixed in the proportions necessary for a particular case, are fed to the rolls of a press granulator. Under the influence of the press rolls, the granules are compressed, they are introduced into each other, which is accompanied by the emergence of molecular adhesion forces between the individual components. As a result, granules of multicomponent fertilizers having a mixed composition are formed at the exit of the die of the matrix.

The inventive method is far from obvious. It was previously believed that it was impossible to obtain granules of complex fertilizers by dry pressing directly from granules of individual fertilizers. In all known technologies described in scientific, technical and patent sources, pressing is made from crushed, in the extreme case, caked, lumpy source material, but not from granules of finished fertilizers. The achievement of the specified technical result using a press granulator, despite the apparent simplicity, was not previously known from the prior art.

The claimed invention is illustrated by graphic materials, which depict:

figure 1 - design of a press granulator with a cylindrical matrix;

figure 2 - the design of the pellet mill with a flat matrix. The inventive method can be carried out, for example, in a press granulator (Fig. 1), consisting of a rotating cylindrical matrix 1 and rolls 2. In the matrix 1, dies 3 are made. Knives 4 are installed on the outer surface of the cylindrical matrix 1 for cutting granules of the finished multicomponent fertilizer . The rollers 2 are mounted rotatably on the axes 5.

Press granulator with a flat matrix (figure 2), with which the inventive method can also be carried out, contains a flat matrix 6, on which the rolls 7 are rolled. In this case, the rolls 7 are made conical. In the matrix 6, dies are made 8. Using a drive (not shown in FIG. 2), rotation is transmitted through the shaft 10 to the rolls 7, which rotate around the axes 9.

The method is as follows. The mixture of granules in the proportions necessary to obtain multicomponent fertilizer is fed (see FIG. 1) into the rotating cylindrical matrix 1 through the loading nozzle (not shown in FIG. 1). Depending on the particular design, the drive rotates the cylindrical matrix 1 (as shown in FIG. 1) or the roll holder around the central axis of the press granulator. Rotating around their own axes 5, the rolls 2 are rolled over a mixture of granules and pressed on the inner surface of the cylindrical matrix 1. At a certain stage of compaction, the crystalline blocks are deformed on the surface of the granules, they partially collapse, and molecular cohesion forces arise between the various components. Then, the extruded mixture is extruded through die 3, during which a granular structure is formed containing the components of the initial source granules. At the exit of the die 3, the granules break off with the help of knives 4.

Depending on the composition of the initial mixture of granules, the necessary pressure of the rolls 2, as well as the sizes of the dies 3 are selected.

Pressing and granulating fertilizers on a flat-die pellet mill 6 (FIG. 2) is carried out similarly. The mixture of granules is fed to the surface of the matrix 6, on which rolls 7 are rolled with pressure. Granules of multicomponent fertilizer are formed in dies 8.

The possibility of carrying out the claimed invention is the production of granules of two or more component fertilizers directly from a mixture of granules of various fertilizers without preliminary grinding using a press granulator is confirmed by tests conducted by the applicant.

The feedstock for obtaining a complex three-component fertilizer was the finished granules of individual fertilizers: P - phosphorus (ammophos), N - nitrogen (ammonium nitrate), K - potassium (potassium chloride). Information about the source materials are given in table. 1.

Press granulator brand Buller-420 [BuhlerAG], which was tested, had the design shown in figure 1. The technical characteristics of this press granulator and information about the granulation modes are given in table. 2.

As a result of the tests, cylindrical granules of three-component fertilizer were obtained, each of which contains all three elements: P - phosphorus, N - nitrogen and K - potash. The deviation of the composition in each of the finished granules from the original in the loaded mixture was not more than ± 10%.

Tests of the obtained granules were carried out in accordance with the requirements established by state standards. The test results confirm that the obtained granules of complex fertilizers meet these requirements.

The test results of the granules of multicomponent fertilizers obtained directly from the mixture of granules are shown in table. 3.

Sources of information

1. RF patent No. 2111940 "Method for producing granular fertilizers", IPC C 05 G 1/00, priority 01.07.97, public. 09/20/98.

2. Application of Germany (DE) No. 3530297 "Fertilizer in the form of rods and method for its production", IPC C 05 G 5/00, public. 02/26/87.

3. PCT application No. 88/03521 "Granular fertilizer and method for its production", IPC C 05 G 5/00, public. 05/19/88.

4. A.S. USSR No. 1212547 "Granulator", IPC B 01 J 2/12, priority 05/18/84, public. 02/23/86.

5. International application WO No. 9534375 "Granulator for loose material", IPC B 01 J 2/20, priority 13.06.95.

6. Application Japan (JP) No. 63-134045 “Granulator”, IPC B 01 J 2/20, public. 06.06.88.

7. Application Japan (JP) No. 3-34977 "Multistage granulator", IPC B 01 J 2/20, the public. 05.24.91.

8. Application of Germany (DE) No. 3342660 "Two-stage granulator", IPC B 01 J 2/20, public. 06/05/85.

9. Kuvshinnikov I.M. Mineral fertilizers and salts. - M .: Chemistry, 1998, p. 37-43.

10. Guidelines for determining the physico-mechanical properties of mineral fertilizers. - M., 1979.

11. Guidelines TSINAO. - M., 1979.

12. Laboratory and practical classes in soil science. - L .: Kolos, 1967.

13. GOST 21560.2-82, (ST SEV 2527-80). Mineral fertilizer. Method for determining the static strength of granules.

14. GOST 20851.4-75. Mineral fertilizer. Methods for determining the water content.

Claims (1)

A method of producing a granular multicomponent fertilizer, comprising mixing granules of two or more fertilizers and granulating them, characterized in that the granulation of said mixture of granules is carried out in a press granulator by compaction of said mixture of granules with press rolls of a press granulator and extrusion of the compressed mixture of granules through die granules of a press granulator .

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