SK9842Y1 - Solid fertilizers - Google Patents

Abstract

Solid mixed fertilizers containing urea phosphate - CO(NH2)2.H3PO4 are described. By dissolving these fertilizers, nutrient solutions are obtained having the required chemical reaction (pH) without the addition of other additives. The mixed fertilizers can be in powder form or in the form of granules, tablets or briquettes. Fertilizers are suitable for preparing a fertilizing solution or for hydroponic cultivation.

Description

The field of technology

The solution concerns solid fertilizers, which in the form of aqueous solutions are suitable for plant nutrition, especially in the form of fertilizer drip irrigation, for fertilizing decorative plants, as well as for the preparation of nutrient solutions intended for soilless - hydroponic cultivation.

Current state of the art

Currently, in connection with plant nutrition, especially in gardening practice and also in the preparation of the so-called nutrient solutions used in connection with soilless - hydroponic cultivation uses several powdered fertilizer mixtures. These are usually designed to be a source of all essential plant biogenic elements, often also a source of trace plant nutrients, and some also contain some of the secondary nutrients, i.e. calcium, magnesium and sulphur. In general, these fertilizers should be completely soluble in water, should contain as few chloride and sodium ions as possible, the content of abiogenic so-called of risk ions in the fertilizer must comply with the applicable legislation and it is advantageous if their composition is chosen so that the aqueous solutions of these fertilizer mixtures have the required chemical reaction - pH, as well as electrical conductivity (EC).

In order to achieve the desired - optimal representation of individual plant nutrients, a range of different salts and acids are used in their preparation, which are the source of individual biogenic elements. In their preparation, primarily ammonium, potassium, magnesium nitrate, urea, some of the ammonium and potassium phosphates, ammonium sulfate, magnesium, boric acid, sodium tetraborate - borax, manganese, zinc and copper sulfate or nitrate are used, and possibly also some complex compounds of biogenic elements.

Solid fertilizers of this type are usually in powder form, more rarely they are also in tablet form. They are used by adding a corresponding amount of solid fertilizer to the amount of water, as recommended by the fertilizer manufacturer, and after its dissolution, the solution prepared in this way is used for plant nutrition. Aqueous solution of fertilizer can be used to feed plants by watering them, apply it in the form of so-called drip fertilizer irrigation, or some of them are also suitable for soilless - hydroponic growing of plants. Aqueous solutions of the type in question can be used to feed economically cultivated plants, especially all kinds of vegetables and flowers, but also in connection with hobby cultivation. They are also suitable as a suitable source of nutrition for decorative plants with both flowers and leaves.

The essence of the technical solution

Despite the fact that most of the currently produced and used solid mixed fertilizers have good properties and provide plants with the necessary nutrients in a suitable form and also in the necessary mutual proportions, they also have some disadvantages. By dissolving several fertilizers of the type in question, nutrient solutions are obtained that do not have the required chemical reaction - pH. This is particularly unsuitable if the water used for dissolution has too high a content of bicarbonates and dissolved alkaline earths, i.e. if it is defined as so-called hard, or if the fertilizer solution is to be used for feeding the so-called acid-loving plants (hydrangeas, rhododendrons, conifers, etc.). In order to at least partially eliminate the mentioned deficiency, some manufacturers of special fertilizers of the mentioned type add various acid-reactive components to the fertilizers, which, however, in most cases are not a source of any plant nutrients and usually dilute the fertilizers and also increase their price (e.g. crystalline carboxylic acids). Some of the additives of the mentioned type also worsen the properties of the solid fertilizer mixture - they increase the electrical conductivity of the solution (EC), cause a decrease in its solubility, increase the tendency of the mixture to agglomerate - "sintering, etc.

It was found that the mentioned shortcomings can be eliminated by solid mixed fertilizers containing urea phosphate - CO(NH ₂ ) ₂ .H ₃ PO ₄ .

Urea (H ₂ NCONH ₂ ), due to the chemical structure of the molecule, is able to form addition compounds with a whole range of inorganic and organic substances (Sulajman-kulov. K., Soedinenija carbamide s neorganičeskimi soljami, Izd. Ilim, Frunze 1971). Professional literature states that an adduct of the type: CO(NH2)2.H3PO4 crystallizes from the ternary system: H3PO4 CO(NH2)2 - H2O (Matignon, S. - Dodge, D.: Compte rendus, 194, 1289, 1932, Bull. Soc. Chim. France, 1, 1114, 1934, Blidin. VP et al.: Ž. prik. chim., 30, 646, 649, 1957). This equimolar addition salt: CO(NH2)2.H3PO4 (CAS No. 4401-74-5, EC No. 225-464-3), which is known by its unique chemical name as uronium trihydrogen phosphate, but usually just as phosphate urea or as urea phosphate, is currently industrially produced and thus also practically used.

Urea phosphate is a white, crystalline salt with an acidic chemical reaction, theoretically containing 17.72% amide nitrogen (as N) and 19.60% phosphorus (as P). Its melting point is approx. 117 °C, while at a higher temperature it undergoes thermal decomposition leading to molecular dehydration of the phosphate anion.

Currently, urea phosphate is industrially produced and used primarily as a nitrogen-phosphorus fertilizer (17-44-0), also as a special catalyst or as an intermediate in the production of highly concentrated liquid fertilizers based on condensed phosphates (15 to 17% N and 28 to 29 % P ₂ O ₅ ). Especially in connection with the production of liquid fertilizers, the chemical reaction between urea and phosphoric acid is often used as a method of cleaning the so-called extraction acid, obtained by the decomposition of phosphates by the action of mineral acids (especially by the action of sulfuric acid).

Urea phosphate in an aqueous environment provides phosphoric acid, so this addition compound can be advantageously used for the desired acidification of the environment.

Among the significant advantages of the solution, the fact that urea phosphate consists of two very important components from the point of view of plant nutrition, such as: urea and trihydrogen phosphoric acid, should be highlighted. Their presence in mixed fertilizers in no way dilutes them and does not introduce any ballast substances.

Supplementing the mixture of fertilizer raw materials with urea phosphate also makes it possible to appropriately influence the often not entirely appropriate chemical reaction of aqueous solutions prepared by dissolving the fertilizer. It turned out to be particularly suitable if the application solutions obtained by dissolving the mixed fertilizer according to the solution in water have an acidic chemical reaction, while the following applies for their chemical reaction: 2.5 < pH > 6.8. The presence of urea phosphate in solid mixed fertilizers enables the preparation of fertilizers even for strongly acid-loving plants, which was usually not possible with fertilizers of the type in question until now. Phosphoric acid, which is released in the water environment, also enables the often necessary treatment of water alkalinity, especially if it has a higher content of bicarbonates and alkaline earth cations, which is also important in terms of nutrient availability.

It has also been found that it is particularly advantageous if the solid fertilizers according to the solution contain a minimum of 4 and a maximum of 65 parts by weight of urea phosphate per 100 parts by weight of the final product.

It has also been proven that the presence of urea phosphate in solid fertilizers according to the solution improves the processability of powder mixtures in the form of tablets, compact bodies or briquettes. In order to increase the handling properties, it is expedient to modify the mixed fertilizers according to the solution by the effect of pressure into a granulated compact form or into the form of tablets or briquettes.

Implementation examples

The following examples clarify and document the solution in question, but in no way limit the claims for its protection.

Example 1

In order to prepare a powder mixture intended for its subsequent processing into the form of briquettes, the following were homogenized by mixing:

450 kg of technical potassium nitrate, KNO3,

450 kg of crystalline urea phosphate, CO(NH2)2.H3PO4, kg of technical potassium sulfate, K2SO4 and kg of crystalline ammonium sulfate, (NH4)2SO4.

The prepared mixture contained:

more than 1.0 wt. % nitrogen (as N) in ammoniacal form, more than 5.8 wt. % nitrogen (as N) in nitrate form, more than 7.6 wt. % nitrogen (as N) in amide form.

The total nitrogen content in the mixture (as N) was more than 14.5 wt. %, the total phosphorus content (as P2O5) was 19.8 wt. % and the total content of potassium in chlorine-free form (as K ₂ O) was 23.3 wt. %.

The prepared mixture of fertilizer components contained even more than 2.0 wt. % sulfur (as S). The mixture of the mentioned chemical composition was the effect of the pressure force acting between oppositely rotating shaped cylinders (fa. Bepex), processed into the form of briquettes intended for stock fertilization of conifer seedlings.

Example 2

In a similar way as in example 1, fertilizer briquettes were prepared from a mixture containing:

material % of crystalline urea phosphate, CO(NH2)2.H3PO4 and wt. % technical potassium nitrate, KNO3.

Example 3

For fertilizing decorative plants with decorative leaves, grown in a nutrient solution - hydroponically, a mixed fertilizer was prepared by mixing in the sense of a solution in powder form.

During the preparation of the mixed fertilizer, the following were homogenized:

material parts of crushed ammonium nitrate granules, NH4NO3, wt. parts of technical potassium nitrate, KNO3, wt. parts of technical potassium dihydrogen phosphate, KH2PO4, wt. parts of crystalline urea phosphate, CO(NH2)2.H3PO4,

2.5 wt. part of powdered calcined magnesium sulfate, MgSO4, and

0.5 wt. parts of a powdered mixture of zinc, manganese, copper sulfates, boric acid and crystalline ammonium molybdate.

The mixture was thoroughly homogenized and ground using a kitchen mixer. In the above-mentioned way, mixed fertilizer was prepared according to the solution, which contained:

6.9 wt. % nitrogen (as N) in ammoniacal form, 10.95 wt. % nitrogen (as N) in nitrate form, 1.6 wt. % nitrogen (as N) in amide form, 13.3 wt. % of total phosphorus (as P2O5) bound in orthophosphate form, 19.9 wt. % of potassium (as K2O) in chlorine-free form and 0.8 wt. % magnesium (as MgO). The prepared mixture was also a source of basic trace biogenic elements and plant-accessible sulfur. The prepared fertilizer was used for the preparation of the nutrient solution used for hydroponic growing of decorative plants, as well as for the preparation of the fertilizer dressing of flowers with decorative leaves. When preparing the application solution, approximately 1.5 g of the powder mixture was dosed per liter of tap water. By measuring the pH of aqueous solutions of solid fertilizer, the following values were determined:

pH of a 1% solution in distilled water: 3.12, pH of a 1% solution in tap water (approx. 12 °N): 3.68.

Example 4

In order to prepare the powdered mixed fertilizer according to the solution, the following was homogenized:

18.17 wt. % ground granulated ammonium nitrate, NH4NO3,

5.0 wt. % ground urea phosphate, CO(NH2)2.H3PO4,

5.43 wt. % of technical potassium dihydrogen phosphate, KH2PO4,

14.63 wt. % technical potassium sulfate, K2SO4

44.65 wt. % technical potassium nitrate, KNO3,

9.12 wt. % of powdered calcined magnesium sulfate, MgSO4, and

3.0 wt. % powdered microelement mixture.

The microelement mixture consisted of: 2.31 wt. part ZnSO4.H2O, 4.85 wt. part CUSO4.5H2O, 12.61 wt. part MnSO4.H2O, 11.6 wt. part H3BO3, 0.38 wt. part (NH4)gMo7O24.4 H2O, 36.7 wt. part of powdered iron chelate (Dissolvine D-FE-11) and 31.55 wt. parts of a crystalline chelating agent (H EDTA).

The prepared mixture of trace plant nutrients contained: 9.96 wt. % nitrogen (as N) in amide form, 3.36 wt. % sulfur (as S), 0.81 wt. % zinc (as Zn), 1.21 wt. % copper (as Cu), 4.04 wt. % manganese (as Mn), 2.02 wt. % boron (as B), 0.2 wt. % molybdenum (as Mo) and 4.04 wt. % iron (as Fe) bound in DTPA chelated form. A solid mixed fertilizer containing 13.13 wt. % of total nitrogen (as N), 5.0 wt. % phosphorus (as P2O5), 30.0 wt. % potassium (as K2O), 3.0 wt. % magnesium (as MgO) and 5.1 wt. % sulfur (as S). By dissolving in water, an application nutrient solution was obtained, which contained the mentioned nutrients and also trace elements bound in a complex form. The prepared fertilizer was especially suitable for feeding flowering and fruit-producing plants.

Example 5

In order to prepare a mixed fertilizer according to a solution intended for universal application, the following were homogenized:

4.41 wt. % crystalline urea phosphate, CO(NH2)2.H3PO4,

33.09 wt. % of ground granules of ammonium nitrate, NH4NO3,

7.28 wt. % of technical potassium dihydrogen phosphate, KH2PO4,

44.19 wt. % of technical potassium nitrate, KNO3, a

11.03 wt. % calcined magnesium sulfate, MgSO4.

The powder-crystalline mixture prepared in this way was thoroughly homogenized and prepared into a powder form by grinding.

Powdered mixed fertilizer containing 17.69 wt. % of total nitrogen (as N), 5.7 wt. % phosphorus (as P2O5), 22.81 wt. % potassium (as K2O), 3.63 wt. % magnesium (as MgO) and 2.91 wt. % sulfur (as S). The ratio of basic nutrients in the fertilizer was: 3.1 - 1 - 4.0.

Example 6

The powder mixture prepared by the method described in example 5 was enriched with trace biogenic elements. This was done by adding 5 parts by weight of the microelement mixture specified in Example 4 to 95 parts by weight of the powdered fertilizer mixture. Thorough homogenization of the mixture resulted in a fertilizer according to the solution in powder form, which contained: 16.8 wt. % nitrogen (as N), 5.41 wt. % phosphorus (as P2O5), 21.67 wt. % potassium (as K2O), 3.45 wt. % magnesium (as MgO), 2.76 wt. % sulfur (as S), 0.0405 wt. % zinc (Zn), 0.0605 wt. % copper (as Cu), 0.202 wt. % manganese (as Mn), 0.101 wt. % boron (as B), 0.01 wt. % molybdenum (as Mo) and 202 wt. % iron (as Fe).

Part of the prepared powder fertilizer was processed by tableting. The prepared tablets with a diameter of 25 mm, a height of 12-14 mm, had an average weight of 10 g. One tablet was intended for the preparation of approx. 10 liters of fertilizer dressing.

Example 7

The powder mixture containing basic and trace plant nutrients according to examples 5 and 6 was prepared into the form of compacted crumbs, i.e. a compact body. The mixture was compacted after it was slightly moistened with water between two counter-rotating cylinders. The compacted plastic prepared in this way partially broke after cooling, while particles of 2 to 4 mm in size were separated by sieving from the obtained mixture forming the product - a coarse granulate of the mixed fertilizer according to the solution.

Industrial applicability

It is characteristic of solid mixed fertilizers according to the solution that, in addition to the components that are a source of basic, secondary and trace plant nutrients, they contain urea phosphate - CO(NH2)2.H3PO4. By dissolving these fertilizers, nutrient solutions are obtained that have the desired chemical reaction even without the addition of other additives. The mixed fertilizers according to the solution can be in powder form or they can be transported under pressure in the form of granules, tablets or briquettes. They are suitable for the preparation of a fertilizing solution, but they can also be advantageously used in connection with soilless - hydroponic cultivation. The preparation of mixed fertilizers according to the solution is easy.

Claims (4)

CLAIMS FOR PROTECTION 1. Solid mixed fertilizers, characterized by the fact that CO(NH2)2.H3PO4. 2. Solid mixed fertilizers according to claim 1, characterized in that they contain 4 to 65 parts by weight of urea phosphate. 3. Solid mixed fertilizers according to claim 1, characterized in that they contain urea phosphate, in that 100 by weight, in that their application solutions prepared by dissolving in water have an acidic chemical reaction, while the following applies to their chemical reaction: 2.5 < pH > 6.8. 4. Solid mixed fertilizers according to claim 1, characterized in that they have the nature of powder, granulate, tablets or briquettes.