BG110579A - Concentrated phosphorus-potassium liquid fertilizer with microelements and method for its production - Google Patents

Abstract

The concentrated phosphorus-potassium liquid fertilizer with microelements is used for leaf and root feeding of the plants by means of spraying, fertigation or hydroponics. During the preparation of the process solution (the dissolving in water), it can be used in combination with nitrogen fertilizers. It can also serve as a base solution for production of complex NPK liquid fertilizers by addingnitrogen-containing components (carbamide, ammonia nitrate, ammonia sulphate, ammonia thiosulphate, etc.). The concentrated phosphorus-potassium liquid fertilizer with microelements contains (in weight %): R2O5 from 14 to 26, K2O from 14 to 30, at least one of the following microelements: 0.01-1% V%, 0.002-0.2% So, 0.02-0.2% Su, 0.02-2% Re, 0.01-1% Mn, 0.001-0.1% Mo, 0.002-0.2% Zn and at least one chelate forming agent, preferably disodium salt of ethylenediaminetetraacetic acid. The liquid fertilizer is a clear green solution with maximal concentration of the main nutrition elements and verygood physical and chemical properties required for the leaf fertilizers: stability during prolonged storage, low crystallization temperature below 0?S, low salt index from 4.1 to 9.2, rN from 6.0 to 8.5, low evaporation rate, maximal buffer capacity, absence of creeping crystallization and corrosion activity. In accordance with the invention, the method for production of the liquid fertilizer consists of dissolving ortophosphoric acid and potassium hydroxide in a ôthermal bufferö û ready product, after which solution of microelements is added, obtained by dissolving inorganic salts of the microelements and chelate-forming agents in water.

Description

Technical field

The present invention relates to a concentrated phosphorus-potassium liquid trace element with trace elements and to a process for its preparation. It can be used both individually and in combination with nitrogen fertilizers for foliage and root nutrition of plants after proper dilution with water. It can also serve as a base solution for the preparation of complex NPK liquid fertilizers by adding nitrogen-containing components (urea, ammonium nitrate, ammonium sulfate, ammonium thiosulfate, etc.).

BACKGROUND OF THE INVENTION

The tendency of a continuous increase in the assortment of liquid fertilizers intended for foliar and root nutrition of plants is evidence of the usefulness and effectiveness of this method of fertilization on an increasing scale. Typically, these are complex fertilizers containing all three basic nutrients nitrogen (N), phosphorus (P) and potassium (K) obtained by dissolving crude and salts containing these elements in water.

These solutions are very convenient to use because they are imported simultaneously by all three essential nutrients (Ν, Ρ and K), but they also have their disadvantages, the essential ones of which are:

1. Lower concentration of nutrients compared to solutions containing only one or two of the essential nutrients.

2. The ratio of Ν, P and K is fixed, but different plants have different needs for this element. In addition, the needs of even the same plant of Ν, Ρ and K change during different stages of its development.

3. The form of nitrogen (amide, ammonium, nitrate) is also fixed, but it is well known that the best form of nitrogen is amide in leaf nourishment and ammonium in root.

4. Most of these complex fertilizers do not meet the increased requirements for their physicochemical properties: high concentration of nutrients and high buffering capacity; low: salt index, vapor pressure, crystallization temperature and corrosion activity; absence of creeping crystallization.

It is therefore a problem to create such a liquid fertilizer that is to the maximum extent satisfying the complex of requirements for this type of fertilizer.

There is a known (according to US Patent No. 3,022,154) method for the preparation of concentrated liquid fertilizers of superphosphoric acid and potassium hydroxide. The term "superphosphoric acid" is defined as phosphoric acid containing ortho- and polyphosphoric acids. Polyphosphoric acids include polyphosphoric acid and other polymers. The properties of polyphosphoric acids vary with the content of P2O5 in superphosphoric acid.

Superphosphoric acid can be obtained by dissolving P2O5 in orthophosphoric acid, by evaporating water from orthophosphoric acid, or by producing thermal orthophosphoric acid at temperatures higher than those required for the normal conduct of the process.

The process involves the continuous introduction of a stream of potassium hydroxide solution containing from 40 to 67% KOH and a stream of superphosphoric acid containing about 75-77% P2O5 in the reaction zone with continuous and vigorous stirring over a temperature range of 27 to 115 ° C. The flow ratio is maintained so that the pH in the reaction zone is in the range of 7.0 to 11.5. The fertilizer solution thus obtained is stable at temperatures below 0 ° C and contains from 23 to 27% P2O5 and from 23 to 36% K ₂ O.

It is possible to prepare by this method solutions with compositions (N - P2O5 K ₂ O): 0 - 27 - 36, 0 - 25 - 25 and 0 - 29 - 31. These solutions can be used directly as liquid fertilizer or, if necessary. mix with suitable nitrogen-containing materials such as urea, ammonium nitrate, diammonium hydrogen phosphate or mixtures thereof and water to obtain NPK liquid fertilizers with compositions: 5-20-20,12-12-12 and 13-13-13.

The proposed method for producing concentrated PK and NPK liquid fertilizers in the above patent has the following disadvantages:

1 · Expensive and scarce raw material is used - superphosphoric acid. The resulting potassium polyphosphates are hydrolyzed to orthophosphates over time, which, due to the saturation of the solution, separates some of them as crystals. 3. The content of the basic nutrients of phosphorus and potassium in the solutions before hydrolysis takes place is slightly higher than in the solutions obtained by neutralizing the cheaper orthophosphoric acid, and after hydrolysis these concentrations are equalized.

SUMMARY OF THE INVENTION

The problem to be solved with the present invention is to provide a phosphorus-potassium trace element fertilizer that can be applied alone or in combination with solid or liquid nitrogen fertilizers, after appropriate dilution with water, for foliar and root nutrition of plants through different phases of their development under conditions guaranteeing high yields and quality of production.

Phosphorus-potassium liquid fertilizer with trace elements can also be used as a basic solution for the preparation of complex NPK liquid fertilizers by adding to it nitrogen-containing components, alone or mixtures thereof - urea, ammonium nitrate, ammonium sulfate, ammonium thiosulfate.

The complex phosphorus-potassium liquid fertilizer with trace elements according to the invention contains: from 14 to 26% P2O5, from 14 to 30% K2O, at least one of the following trace elements in weight. %: 0.01-1% B, 0.002-0.2% Co, 0.02-0.2% Cu, 0.02-2% Fe, 0.01-1% Μη, 0.001-0.1% Mo, 0.002-0.2% Zn and at least one of the following chelating agents Sodium, potassium or ammonium salts of ethylenediamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DTPA), ethylenediamine-di (o-hydroxyphenyl acetic) acid (EDDHA), 2-hydroxyethylethyl diamine HEED (triacetic acid) ethyl acetate -hydroxy-o-methylphenylacetic) acid (EDDHMA), ethylenediamine di- (2-hydroxy-4-carboxyphenylacetic) acid (EDDCHA), or

the acids themselves, the trace elements.

equivalent quantities to the content of

Phosphorus-potassium liquid fertilizer can be used both individually and as a basic solution for the preparation of complex NPK liquid fertilizers by adding to it nitrogen-containing components, alone or mixtures thereof - urea, ammonium nitrate, ammonium sulfate, ammonium thiosulfate and others

The addition of nitrogen-containing components may also occur in the process of preparing the working solution for spraying the plants, i. E. in the dilution of phosphorus-potassium liquid fertilizer is water. In this way the ratios between N, P and K can be varied, and the form of nitrogen (amide, ammonium, nitrate) can also be selected depending on the specific needs.

The complex liquid fertilizer is intended for foliage and root feeding of all kinds of plants. It is a stable, clear solution with a crystallization temperature below 0 ° C, pH 6.0 to 8.5, salt index 4.1 to 9.2.

Another object of the present invention is a method of preparing a complex phosphorus-potassium liquid fertilizer with trace elements by mixing orthophosphoric acid and potassium hydroxide, and adding a solution of trace elements in chelate form.

Orthophosphoric acid and potassium hydroxide are added in small portions with continuous stirring in a reactor, a stirrer and a water jacket are provided to cool the solution. To prevent the reaction from flowing rapidly while mixing the starting reagents, the reactor is partially filled with a prepared, cooled solution that serves as a "thermal buffer". The temperature of the solution during the mixing process varies from 25 to 90 ° C. The mass ratio between orthophosphoric acid (such as P2O5) and potassium hydroxide (such as K2O): m ^ Os) m (K ₂ 0) is in the range of 1: 1 to 1: 1.15, while maintaining the pH of the solution from 6.0 to 8.5. To achieve the necessary concentrations of P2O5 and K2O in the finished product, the required amount of water is added to the reactor.

Orthophosphoric acid can be thermal (TFA) with a concentration of 54 64% P2O5 or extraction (EFK) with a concentration of 30 - 54% P2O5 It is preferable to use TFA. When neutralizing EFC with potassium hydroxide, the impurities contained in it are separated as a gel-like, hardly filtered precipitate.

Potassium hydroxide must be at least 85% pure. It can be used in both solid and solution form.

The trace elements are introduced in the form of inorganic salts of these elements. Iron, manganese, zinc, copper and cobalt are preferably in the form of sufates, boron is preferably in the form of borax (Na ₂ B4O7.10H ₂ O) or boric acid (H3BO3), and molybdenum in the form of molybdates ( sodium, potassium, ammonium). The chelating agent is preferably the disodium salt of ethylenediaminetetraacetic acid (Na ₂ EDTA) in solution or in solid form.

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The trace element solution is obtained by dissolving inorganic salts of these elements and a chelating agent, taken in stoichiometric proportions, in water. The sequence of adding components to the water is irrelevant. The trace element solution thus prepared is added under continuous stirring to the potassium orthophosphate solution.

The advantages of the liquid fertilizer according to the invention are the following:

1. Phosphorus-potassium liquid fertilizer with trace elements can be used alone or after the addition of nitrogen-containing components to it, for foliar feeding, fertigation, hydroponics and as a starter fertilizer, thereby increasing yields and improving the quality of production.

2. The addition of nitrogen-containing components may also occur during the preparation of the working solution. This makes it possible to obtain solutions with any ratio of nitrogen, phosphorus and potassium, nitrogen may be in different forms (amide, ammonium, nitrate and organic) depending on the method of application of the liquid fertilizer and the type of plant.

In addition, the phosphorus-potassium liquid fertilizer with trace elements meets the most up-to-date requirements for special liquid fertilizers for foliage and root nutrition of plants:

1. Maximum total concentration of P2O5 and K ₂ O in solution from 28 to 56% lower transport and storage costs.

2. Minimum salt index from 4.1 to 9.2 - possibility of application of the working solution in higher concentrations without danger of damaging the plants and damaging them.

3. Low evaporation rate - sufficient time is provided for the complete absorption of nutrients from the leaf mass.

4. Maximum buffer capacity - the solution remains stable, clear for prolonged storage.

5. Low crystallization temperature (below 0 ° C) - possibility for storage in unheated premises.

6. Absence of creeping crystallization and corrosion activity, seamless storage and transportation in any kind of containers, possibility of using any technique for spraying and fertigation.

7. Very good adhesive properties - it is not necessary to bring the so-called "adhesives" into the working solution with foliar nourishment.

8. Phosphorus and potassium are in the form of potassium orthophosphates, possibly the best form for plants - physiologically neutral, high rate of penetration in leaves, fungicidal action against certain plant diseases, very high agrochemical efficiency.

9. A stable, complex NPK liquid fertilizer with a maximum concentration of nutrients can only be obtained on the basis of a solution of potassium orthophosphates - such as the phosphorus-potassium liquid fertilizer described in the present invention.

An exemplary embodiment of the invention

The following embodiments of the invention will elucidate it without limitation.

Example 1

Pour 43.8 g of water into a 250 ml beaker equipped with a stirrer and add 3 g of orthophosphoric acid (85% H 3 PO 4) and 25.2 g of potassium hydroxide (90% KOH) in continuous stirring. A clear, colorless solution of potassium orthophosphates (highly concentrated PK liquid fertilizer) was obtained with the following parameters: 19% P2O5, 19% K ₂ O, pH = 6.7, d = 1.39, crystallization onset temperature T = 20 ° C. This solution will be referred to as stock solution A.

Pour 34g of water into a 100ml glass and dissolve 2.8g of ethylenediaminetetraacetic acid disodium salt (Na ₂ EDTA), 1.0 Og FeSO4.7H2O, 0.3 lg MnSO ₄ .H ₂ O, 0.27g CuSO ₄ .5H ₂ O, 0.30g ZnSO ₄ .7H ₂ O, 0.02g (NH ₄ ) ₆ Mo ₇ .4H ₂ O, 0.89g Na ₂ B ₄ O7.10H ₂ O, and 0.40g KOH. This gives a 40g solution of chelated trace elements with the following parameters: 0.25% B, 0.17% Cu, 0.5% Fe, 0.25% Μη, 0.025% Mo, 0.17% Zn, pH - 3.1, d = 1.08, onset temperature. crystallization below 0 ° C. This solution will be referred to as stock solution B.

In a 250 ml beaker, mix 100g of stock solution A, 16.5g of stock solution

B and 19.2g of water. Concentrated phosphorus-potassium liquid fertilizer with chelate trace elements was obtained with the following parameters: 14% P2O5, 14% K ₂ O, 0.03% B, 0.02% Cu,

0.06% Fe, 0.03% Μη, 0.003% Mo, 0.02% Zn, pH = 6.3, d = 1.27, crystallization onset temperature below 0 ° C. This solution will be referred to as solution C.

The phosphorus-potassium trace element fertilizer obtained from Example 1 (Solution C) can be used as a final product and also as a basic solution for the preparation of NPK liquid fertilizers by adding nitrogen-containing components. For example:

(la) Pour 100g of phosphorus-potassium liquid fertilizer with trace elements (solution C) into a 250 ml beaker and add 30.5g of urea and 9.5g of water to it. An NPK trace element liquid fertilizer containing amide form nitrogen is obtained, suitable for leaf feeding with the following parameters: 10% N, 10% P2O5, 10% KrO, 0.021% B, 0.014% Cu, 0.042% Fe, 0.021% Μη, 0.002% Mo, 0.014% Zn, pH = 7.5, d = 1.26 crystallization onset temperature below 0 ° C.

(lb) Pour 100g of phosphorus-potassium liquid fertilizer with trace elements (solution C) into a 250 ml beaker and add to it 41.2g of ammonium nitrate and 58.8g of water. An NPK liquid fertilizer containing ammonium and nitrate nitrogen, suitable for root feeding with the following parameters, is obtained: 7% N, 7% P2O5, 7% K2O, 0.015% B, 0.01% Cu, 0.03% Fe, 0.015% Μη, 0.0015% Mo, 0.01% Zn, pH = 6.0, d = 1.22, crystallization onset temperature below 0 ° C.

(lc) Pour 100 g of phosphorus-potassium liquid fertilizer with trace elements (solution C) into a 250 ml beaker and add to it 15.4g of urea, 20.4g of ammonium nitrate and 39.2g of water. An NPK liquid fertilizer containing nitrogen in amide, ammonium and nitrate form is obtained, suitable for root feeding with the following parameters: 8% N, 8% P ₂ O ₅ , 8% K ₂ O, 0.017% B, 0.011% Cu, 0.034 % Fe, 0.017% Μη, 0.0017% Mo, 0.011% Zn, pH = 6.5, d = 1.23, crystallization onset temperature below 0 ° C.

Example 2

Work as in Example 1. In a 500 ml beaker equipped with a stirrer pour 24.9g of water and add in small portions with continuous stirring 39.6g of orthophosphoric acid (85% H ₃ PO ₄ ) and 35.5g of potassium hydroxide (90% KOH). A clear, colorless solution of potassium orthophosphates (highly concentrated PK liquid fertilizer) was obtained with the following parameters: 24.4% P2O5, 26.8% K2O, pH = 8.0, d = 1.58, crystallization onset temperature T = 20 ° C.

To this solution was added 9.8g of the trace element solution (solution B), the method of preparation of which was described in Example 1. A concentrated phosphate-potassium liquid fertilizer with trace elements in chelate was obtained with the following parameters: 22.2% P ₂ O ₅ , 24.5% K ₂ O, 0.022% B, 0.015% Cu, 0.044% Fe, 0.022% Μη, 0.002% Mo, 0.015% Zn, pH = 7.8, d = 1.51, crystallization onset temperature below 0 ° C.

Example 3

Work as in Example 1. Pour into a 500 ml beaker equipped with a stirrer

8.6g of water, and 46.3g of orthophosphoric acid (85% H3PO4) and 45.g of potassium hydroxide (90% KOH) were added continuously with continuous stirring. A clear, colorless solution of potassium orthophosphates (highly concentrated PK liquid fertilizer) was obtained with the following parameters: 28.5% P ₂ O ₅ , 34.1% K ₂ O, pH = 9.5, d = 1.72, crystallization onset temperature T = 20 ° C. .

To this solution was added 18.6g of water and 11.4g of the trace element solution (solution B), the method of preparation of which was described in Example 1. A concentrated phosphate-potassium liquid fertilizer with trace elements in chelate was obtained with the following parameters: 21.9% P ₂ 0s, 26.3% K ₂ O, 0.022% B, 0.015% Cu, 0.044% Fe, 0.022% Μη, 0.002% Mo, 0.015% Zn, pH = 8.4, d = 1.52, crystallization onset temperature below 0 ° S.

Field tests have been carried out in different agricultural fields

complex liquid manure institutes and test stations, with composition and method of preparation, described in Example (1a). The effect of leaf treatment, depending on phenophases and doses of application, on the development, yield and quality of the following crops was studied: wheat, soybean, fodder peas, alfalfa, faye, potatoes, cotton. Doses of 0.4 to 0.8 l / ha have been tested at concentrations of working solutions of 0.4 to 1%, applied once and twice by spraying with a tube sprayer during the various phases of vegetative development. Foliar feeding with complex liquid fertilizer has been found to stimulate plant growth and productivity. The yield increase for different crops is 15 to 40% compared to the control.

Claims (7)

Patent Claims 1. Concentrated phosphate-potassium liquid fertilizer with trace elements, characterized in that the content of diphosphorus pentaoxide is from 14 to 26%, the content of potassium oxide is from 14 to 30%, contains at least one of the following trace elements: 0.01-1% B, 0.002-0.2% Co, 0.02-0.2% Cu, 0.02-2% Fe, 0.01-1% Μη, 0.001-0.1% Mo, 0.002-0.2% Zn and at least one chelating agent in stoichiometric amount relative to the trace element content. 2. Concentrated phosphorus-potassium liquid fertilizer is a trace element according to claim 1, characterized in that the chelating agent is in the group of the sodium, potassium or ammonium salts of ethylenediamine tetraacetic acid, diethylenetriamine pentacetic acid, ethylenediene-hydroxyamine-ethylenediamine-hydroxyethylamine acid, 2hydroxyethylene diamine trioacetic acid, ethylenediamine-di (hydroxy-o-methylphenylacetic) acid, ethylenediamine di- (2-hydroxy-4carboxyphenylacetic) acid or the acids themselves. 3. A method for producing concentrated phosphorus-potassium liquid fertilizer is a trace element according to claim 1, characterized in that orthophosphoric acid and potassium hydroxide are added in small portions with continuous stirring with continuous stirring, and then a solution of potassium hydroxide is added. chelate trace elements obtained by dissolving inorganic salts of trace elements and chelating agent in water. The method according to claim 3, characterized in that the orthophosphoric acid is thermal with a concentration of 75-85% H 3 PO 4. The process according to claim 3, characterized in that the potassium hydroxide is 85-90% pure and added in solid or as a solution. Method according to claim 3, characterized in that the salts of the trace elements are preferably sulphates of iron, manganese, copper, zinc and cobalt, boron is preferably borax or boric acid, molybdenum is in the form of sodium or ammonium molybdate . Method according to claim 3, characterized in that the chelating agent is preferably a disodium salt of ethylenediaminetetraacetic acid in solution or in dry form.