NPK LIQUID AND SOLID FERTILIZER, OBTAINING PROCESS, FERTILIZING COMPOSITIONS AND USE

Abstract

A process of chemical cleavage of leather or skins containing chromium The process using sodium, potassium or calcium methylates (CH.sub.3O.sup.?) or ethylates (CH.sub.3CH.sub.2O.sup.?), producing chromium hydroxide (green paste), ammonium sulfate and liquid fertilizer. The chromium trioxide III (Cr.sub.2O.sub.3) obtained was used in the production of FeCr alloy. The liquid fertilizer was applied to strawberry, violet and acerola crops, and can be applied to other types of crops. The fertilizer is also compatible with pesticides, being able to compose a composition containing fertilizer and pesticide or even used to obtain products containing fertilizers and pesticides, which allow application in a single step, exempting the process in the field A solid NPK fertilizer formulation obtained by combining N recovered from waste and homogeneously mixed with K and P salts.

Claims

1. A process for producing a fertilizer comprising: a) preparing a methylate or ethylate solution, in a concentration range between 0.01 and 1 mol/L; b) heating the solution obtained in step a) between 50 and 100? C.; c) adding wet blue leather or skin in a leather/reagent/water ratio between 0.1:0.05:0.1 and 1:0.1:1; d) carrying out a cleavage reaction for 30 to 60 minutes; e) neutralizing using nitric or sulfuric or phosphoric acid at a concentration of 1 to 5 mol/L to obtain the fertilizer.

2. The process for producing a fertilizer according to claim 1, wherein the ethylate or methylate solution has sodium, potassium or calcium as counter ion.

3. The process for producing a fertilizer according to claim 1, wherein the ethylate or methylate solution is prepared in situ, adding sodium or potassium or calcium hydroxide and methanol or ethanol to form the methylate or ethylate between 0.1/0.1 and 1/1 methylate/ion ratios.

4. The process for producing a fertilizer according to claim 1, further comprising obtaining a solid 4/14/8 NPK fertilizer by combining the fertilizer obtained in step e) with inorganic salts of K and P.

5. The process for producing a fertilizer according to claim 1, wherein ammonia is generated is retained in a container containing sulfuric acid with a concentration of 10 to 20% by mass during 30 to 60 min of reaction, forming ammonium sulfate.

6. The process for producing a fertilizer according to claim 1, wherein of chromium trioxide is formed and that can be used directly as a source of chromium for production of FeCr alloy.

7. A fertilizing composition containing the fertilizer obtained in the process as defined in claim 1 and a pesticide.

8. A method for using the fertilizing composition according to claim 7, wherein the fertilizing composition is applied in single steps.

9. (canceled)

Description

BRIEF DESCRIPTION OF THE FIGURES

[0015] FIG. 1 (A) presents the photograph of the NPK solid fertilizer obtained in the form of pellets with different ratios of the elements (a) and the 4/14/8 formulation (b).

DETAILED DESCRIPTION OF THE TECHNOLOGY

[0016] The present technology consists of a process of chemical cleavage of leather or skins containing chromium. The process uses sodium, potassium or calcium methylates (CH.sub.3O.sup.?) or ethylates (CH.sub.3CH.sub.2O.sub.?), producing chromium trioxide, ammonium sulfate, solid NPK fertilizer and liquid fertilizer rich in organic nitrogen. The chromium trioxide obtained was used in the production of the FeCr alloy. Liquid fertilizer and solid fertilizer with the 4/14/8 NPK formulation were applied to strawberry, violet and acerola crops, and can be applied to other types of crops. The liquid fertilizer also showed compatibility with pesticides, which allows application in single steps, significantly relieving the process in the field. The process of obtaining fertilizer consists of the chemical cleavage of skin and leather, which may come from urban mining from industrial landfills or from tanneries. The process produces, in addition to liquid and solid fertilizers with NPK formulation, ammonium sulfate and chromium trioxide.

[0017] The process of obtaining fertilizer of the present invention comprises the following steps: [0018] a. preparing the methylate or ethylate solution, in the concentration range between 0.01 and 1 mol/L; [0019] b. heating the solution obtained in step a between 50 and 100? C.; [0020] c. adding wet blue leather or skin in a leather/reagent/water ratio between 0.1:0.05:0.1 and 1:0.1:1, preferably in a ratio of 1:0.1:1; [0021] d. carrying out the cleavage reaction for 30 to 60 minutes; [0022] e. neutralizing using nitric or sulfuric or phosphoric acid at a concentration of 1 to 5 mol/L.

[0023] In step a the ethylate or methylate can have as counter ion sodium, potassium or calcium. Still, the solution can be prepared in situ, adding sodium or potassium or calcium hydroxide and methanol or ethanol to obtain methylate or ethylate between the ratios of 0.1/0.1 and 1/1 of methylate/ion, preferably of 1:1.

[0024] Through the process described, a solid 4/14/8 NPK fertilizer is obtained by combining the liquid fertilizer obtained in step e of the process described above and inorganic salts of K and P.

[0025] The retention of the generated ammonia can be carried out in a container containing sulfuric acid with a concentration of 10 to 20% by mass during 30 to 60 minutes of reaction, thus, forming ammonium sulfate.

[0026] The aforementioned process is capable of forming chromium trioxide that can be used directly as a source of chromium for the production of FeCr alloy.

[0027] The liquid fertilizer obtained from the present invention is compatible with pesticides, herbicides and fungicides in any ratio.

[0028] The fertilizer compositions of the present invention contain the fertilizer defined above and a pesticide in any ratio, and can be applied in a single step.

[0029] Liquid fertilizer can be used to obtain products containing fertilizers and pesticides in any ratio for single step during fertilization.

[0030] The present invention is better understood according to the examples described below.

Example 1Cleavage of Leather and Skin Using Methylates or Ethylates as Catalysts

[0031] The catalysts of the cleavage processes used were sodium methylate, and sodium ethylate, calcium methylate or ethylate or potassium methylate or ethylate can be used. To cleave 100 g of wet blue leather or skin, a solution containing one of the reagents described above was used at a concentration of 1 mL of the reagent in 100 mL of water. It is important, for the proper functioning of the cleavage reaction, that the step is started by heating the reagent between 50 and 100? C. and only then adding the leather. This sequence facilitates the cleavage step, not requiring an increase in temperature, which promotes savings in the cost of the process. The reaction takes place almost instantaneously due to the basic strength of the cleavage agents. However, to ensure complete cleavage, the reaction was run for 30 minutes. In order to reduce the cost of the process, reagents prepared at the time of the reaction were also tested, adding sodium hydroxide and methanol or ethanol, in order to produce the methylate or ethylate in situ. Efficiency was the same when using commercially purchased reagents. After the reaction catalyzed by methylate or ethylate, the following products were obtained: dense liquid fertilizer; concentrated ammonium sulfate, which was recovered by bubbling the ammonia generated in the cleavage into a vessel containing dilute sulfuric acid; K or Ca sulfate formed in the concentration of the foliar fertilizer; chromium trioxide (Cr.sub.2O.sub.3). With the total separation of chromium, the obtained liquid fertilizer rich in nitrogen and carbon in the form of amino acids presented the appearance of a brown liquid. Liquid fertilizer was used to produce NPK pellets by reacting with K and P salts (FIG. 1).

Example 2Study of Compatibility with Pesticides and Fertilizing Action of the Leather and Skin Cleavage Product

[0032] For use as a fertilizer and pesticide carrier (atrazine), the material produced from the cleavage of the leather was characterized as to its composition, with a carbon content of 28% and a nitrogen content of 11% by mass. The main amino acids present were glycine, proline, alanine and glutamic acid.

[0033] To add to the cultures tested, 5 mL was diluted in 500 mL of water. After 65 days of experiment in tests with violet, strawberry and acerola, the results were very promising, with a strong effect in the sample that was fertilized weekly, compared to the control experiment, without foliar fertilization. Topdressing fertilization was performed according to plant development, divided into three applications of N and K with 50 mg dm.sup.?3 per application. Initially, the sowing of cultures was carried out. After 14 days, thinning was carried out in the experiment. For all crops, agronomic gain was observed both for cases where no foliar fertilizer was added or for cases where urea was used as a source of foliar N.

[0034] The action observed in different cultures suggests that the material has great versatility and can be used in ornamental plants, fruits and arboreal plants, with a good possibility of being used in eucalyptus and others. The solid material, NPK pellets, still allow for soil fertilization.

Example 3Scale Up Study of the Leather and Skin Cleavage Process

[0035] The process was validated on a pilot scale, using 100 kg of wet blue leather shavings, showing the same efficiency as the procedure performed with 100 g on a bench scale (example 1), which allowed for more realistic process costs with the increase in scale. The process proved to be perfectly possible to be transformed on an industrial scale, since the parameters obtained in the bench tests were reproduced on this larger scale.

Example 4Use of Chromium Trioxide to Produce FeCr Alloy

[0036] Stainless steels are alloys containing iron (Fe), carbon (C) and chromium (Cr) with at least 10.50% Cr by mass. Other metallic elements are also part of these alloys, but Cr is considered the most important element because it is what gives stainless steels high corrosion resistance. In order to carry out the test in an electric furnace, a melting bed similar to those performed in steel mills was prepared, but using recovered chromium, described in the present invention, as raw material. Experimental runs were performed using the chromium obtained. The tests showed that it is technically feasible to obtain the FeCr alloy. The analysis of the alloy obtained indicates that the contents found are close to the expected values for this type of material, that is, Fe, Cr and C contents of 37, 58 and 6% by mass, respectively.