METHOD FOR THE INDUSTRIAL MANUFACTURE OF GRANULATED FERTILIZERS

Abstract

The invention provides a method for the industrial manufacture of granulated fertilizers of the type including the steps of granulation, drying, control of the granule temperature, and sifting, granulation being carried out using a starting material in the form of a thick homogenized suspension in which soluble and insoluble components are present, and in which, prior to the granulation step, said starting material is premixed with other selected raw materials with a high content of nitrogen, phosphorus, potassium, sulfur, calcium, organic matter, micronutrients and combinations thereof.

Claims

1. A method for the industrial manufacture of granulated fertilizers of the type including the steps of granulation, drying, control of the granule temperature, and sifting, wherein the starting material used comprises water-soluble and water-insoluble components in a proportion by weight of 0.5 to 10% with respect to the weight of the product to be granulated in the granulation step, and in that the method includes, prior to the granulation step, a step of obtaining the starting material in the form of a homogenized mixture as a thick aqueous suspension, the soluble and insoluble components being selected from sugars, amino acids, organic acids, polyamines, alcohols, nucleotides, boric acid, leonardite, algae extracts and combinations thereof, and a step of premixing this starting material with other raw materials selected from products with high nitrogen content, products with high phosphorus content, products with high potassium content, products with high sulfur content, products with high calcium content, organic materials, micronutrients and combinations thereof in a proportion between 5 and 90% by weight with respect to the weight of the product to be granulated in the granulation step.

2. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the step of obtaining the starting material with the soluble and insoluble components in the form of homogenized mixture as a thick aqueous suspension is carried out in an in-line disperser.

3. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the pre-mixing step of the starting material with the other raw materials is carried out in a paddle mixer.

4. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the sugars are selected from the group consisting of sucrose, trehalose, fructose, glucose, arabinose, maltose and any combination thereof.

5. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the sugars are present in the granulated fertilizer obtained in a proportion of 0.1 to 15% by weight.

6. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the amino acids are selected from the group consisting of threonine, lysine, phenylalanine, glutamic acid, methionine, γ-aminobutyric acid, omithine, glycine, glutamine, aspartic acid, serine, asparagine, tyrosine, tryptophan, valine, leucine, isoleucine, proline, 4-hydroxyproline, arginine, histidine, alanine, cysteine and any combination thereof.

7. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the amino acids are present in the granulated fertilizer in a proportion of 0.01 to 30% by weight.

8. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the organic acids are selected from the group consisting of succinic acid, oxalic acid, gluconic acid, threonic acid, fumaric acid and any combination thereof.

9. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the organic acids are present in the granulated fertilizer obtained in a proportion of 0.01 to 10% by weight.

10. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the polyamines are selected from the group consisting of putrescine, spermidine, spermine and any combination thereof.

11. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein polyamines are present in the granulated fertilizer obtained in a proportion of 0.01 to 10% by weight.

12. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the alcohols are selected from the group consisting of glycerol and its derivatives.

13. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the alcohols are present in the granulated fertilizer obtained in a proportion of 0.01 to 25% by weight.

14. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the nucleotides are selected from the group consisting of adenine, guanine, cytosine, thymine and any combination thereof.

15. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the nucleotides are present in the granulated fertilizer obtained in a proportion of 0.01 to 5% by weight.

16. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein leonardite is present in the granulated fertilizer obtained in a proportion of 1 to 40% by weight.

17. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the algae extracts are present in a proportion of 0.01 to 15% by weight in the granulated fertilizer obtained.

18. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the products with high nitrogen content are present in the granulated fertilizer obtained in a proportion of 1 to 75% by weight.

19. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the products with high phosphorus content are present in the granulated fertilizer obtained in a proportion of 1 to 75% by weight.

20. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the products with high potassium content are present in the granulated fertilizer obtained in a proportion of 1 to 75% by weight.

21. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the products with high sulfur content are present in the granulated fertilizer obtained in a proportion of 1 to 70% by weight.

22. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the products with high calcium content are present in the granulated fertilizer obtained in a proportion of 1 to 45% by weight.

23. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the organic materials are present in the granulated fertilizer obtained in a proportion of 1 to 40% by weight.

24. The method for the industrial manufacture of granulated fertilizers according to claim 1, wherein the micronutrients are present in the granulated fertilizer obtained in a proportion of 1 to 30% by weight.

25. The method for the industrial manufacture of granulated fertilizers according to claim 1, further including the granulation of the premix together with an aqueous microorganism extract selected from the group consisting of Pichia guilliermondii, Azotobacter chroococcum, Bacillus amyloliquefaciens, Bacillus simplex, Azoospirillum lipoferum, Pantoea alii, Rhizobium radiobacter, Paenibacilus polymyxa and combinations thereof, in an amount between 5 and 90% by weight with respect to the weight of the product to be granulated.

Description

EXAMPLES

General Method for the Industrial Manufacture of Granulated Fertilizers

[0040] The method starts with a combination of water soluble and insoluble components to obtain a starting material in the form of a homogenized mixture as a thick aqueous suspension or slurry, which is added to an in-line disperser. This mixture is added to a paddle mixer together with the different raw materials, wherein a premixing of the raw materials together with the slurry is carried out to subsequently enter the granulation process.

[0041] In the granulation process, the aqueous extract of the different types of microorganisms is added. Once granulation has been carried out, which can be done with any suitable technology, and the granules have been formed, generally with a relative humidity of between 5%-10%, the same are subjected to a drying step, for example in a rotary dryer, to obtain dry granules with a humidity of less than 3%. Subsequently, the entire mass of granules is introduced in a conditioner for gradual temperature reduction to avoid rapid cooling.

[0042] Finally, the product is sifted according to the size selected, the granules with the appropriate size are conveyed for storage of same and those which are outside the size range are conveyed to a mill, where the entire mass is ground to be reintroduced into the granulator.

Exemplary Embodiment for Obtaining a Granulated Fertilizer

[0043] Starting material consists of water-soluble and water-insoluble components:

10% by weight of a combination of: [0044] 60% by weight of pyroglutamic acid [0045] 10% by weight of maltose [0046] 25% by weight of methionine [0047] 5% by weight of putrescine
water up to 100%.

[0048] Once this mixture is made, it is added in a proportion of 0.1% continuously, in order to have 1% in the final fertilizer mixture, to the paddle mixer together with the following raw materials, with a particle size between 300 μm and 1,200 μm, which implies that these raw materials have been previously milled. [0049] 24% by weight of leonardite [0050] 65% by weight of feldspar

[0051] The output humidity of this second mixture ranges between 9% and 15%, since the raw materials also contribute some humidity. The product obtained is introduced into the granulator, where the extracts of the different microorganisms are added in a 10% by weight, the percentage of the extracts of microorganisms varies depending on the concentration of the same, for example between 4% and 18%, so that the final concentration on the fertilizer sample ranges between 0.2% and 2% by weight.

[0052] The granules are formed in the granulator and the humidity is regulated by adding water if required to form the granule. The already formed granulated product comes out of the granulator with a humidity between 6% and 10%. The granules are then introduced into the dryer at a temperature between 330° C. and 380° C. at the head of the process and with an output temperature between 80° C. and 95° C. The output humidity content of the product obtained from the dryer ranges between 2% and 4%.

[0053] The product is then passed through a temperature conditioner for a gradual temperature decrease from 80° C.-95° C. to room temperature, e.g., by applying a stream of dry air, thus preventing the granule from cooling by absorbing humidity.

[0054] Once cooled, the granules will be sifted to obtain a product with an average particle size between 2.5 mm and 5 mm. Granules that are not in this size range will be introduced in a mill to be fed back into the granulator.

Comparative Example

[0055] In order to be able to compare the method described here with conventional granulation processes, a quality analysis of the different components added is carried out, i.e., an analytical measurement of a fixed quantity of granules produced in each of the processes, of the invention and conventional. In this way it can be verified how the manufacture of fertilizers with the method described herein, together with the selected raw materials, provides a high-quality granulated fertilizer.

[0056] For this purpose, as a comparative example, a fertilizer product is obtained using a conventional granulator and the results are compared with the same product obtained according to the method of the invention.

[0057] A representative sample is taken in triplicate, taking for each replicate (R1, R2, R3) 1 kg of sample, from a batch quantity of 100 kg. The parameters analyzed are derived from premixing and adding to the paddle mixer, in particular by measuring the richness of some selected components, the measurement being extrapolatable to the rest of the components of the final fertilizer obtained with each of the processes (measurements obtained by ultra-high resolution liquid chromatography-mass spectrometry).

[0058] The results obtained are shown in the following table:

TABLE-US-00001 Comparative example, in granulator % Error vs. standard Theoretical R1 R2 R3 Average Deviation deviation Pyroglutamic acid 0.60% 0.42% 0.52% 0.69% 0.54% 0.14% 22.75% Maltose 0.10% 0.11% 0.16% 0.07% 0.11% 0.05% 45.09% Methionine 0.25% 0.10% 0.23% 0.19% 0.17% 0.07% 26.63% Putrescine 0.05%   0% 0.02% 0.05% 0.02% 0.03% 50.33% Method according to the invention % Error vs. standard Theoretical R1 R2 R3 Average Deviation deviation Pyroglutamic acid 0.60% 0.59% 0.63% 0.60% 0.61% 0.02% 3.47% Maltose 0.10% 0.11% 0.10% 0.09% 0.10% 0.01% 10.00% Methionine 0.25% 0.23& 0.25% 0.24% 0.24% 0.01% 4.00% Putrescine 0.05% 0.04% 0.05% 0.01% 0.05% 0.01% 20.00%

[0059] As can be observed the error % is considerably reduced in the method according to the invention, which makes it possible to ensure that this novel method for the industrial manufacture of fertilizers is much more homogeneous.