HU207505B - Solide fertilizer of good agrochemical activity containing suspending agent and additives and process for producing them - Google Patents

Abstract

In its granules, a solid fertiliser compsn. contains homogeneously disposed and bound multipurpose additives. The compsn. may be used directly as a solid or in liq. form upon dissolution in water. The compsn. contains: (i) 80-98 wt.% customary N, NP or NPG fertiliser and (ii) 2-20 wt.% pref. 8-12 wt.% homogeneously dispersed soil forming mineral additives. Such compsn. protects the environment, improves the soil and is efficient in use. The compsn. contains sufficient suspending agent for direct prepn. of liq. fertilis

Description

Due to the properties of the additive, the fertilizer has a very beneficial effect, is environmentally friendly, significantly reduces nutrient leaching, provides good utilization of the active ingredient and has a soil improving effect. When used as a slurry fertilizer, you only need to dissolve the fertilizer in water, the suspension agent is already present.

When mixed in a wide variety of basic fertilizers, using clay minerals, we obtain the special additive fertilizer component.

The scope of the description is 6 pages

HU 207 505

HU 207 505 Β

SUMMARY OF THE INVENTION The present invention relates to a solid fertilizer composition comprising an additive which can be used as a suspending agent, which has a favorable agrochemical effect and reduces nutrient leaching, where the additive is homogeneously distributed and fixed in the fertilizer.

It is a known fact that in crop production, proper nutrient management can be considered if the nutrients in the soil cover the nutrients necessary for the development and growth of the crop produced. The nutrients used by the plants must therefore be replenished to maintain soil strength.

Intensive agriculture, high yielding crop production cannot do without fertilization for nutrient supply.

1. Fertilizers can be divided into two broad groups:

1.1. Solid fertilizers (single, compound and complex fertilizers)

1.2. Liquid fertilizers (solution and suspension fertilizers)

In addition to its indispensable positive effects, fertilization has many negative effects, such as incomplete utilization of the active ingredient, soil-damaging effects of fertilizers (eg soil acidification), various environmental hazards (fertilizer leaching, water pollution).

There are several aspects to consider when choosing a fertilizer method: economic issues, equipment and labor requirements, plant nutrient requirements, nutrient utilization rates, environmental protection, etc. That is, the optimum fertilization method must be found between the positive and negative effects.

2. Recently, attention has turned to liquid fertilizers. Its advantages and disadvantages are known. In addition, there is a strong desire within the industry to develop new types of fertilizers that are better suited to agricultural needs in some respects. The present invention also relates to a new fertilizer which has new advantageous properties.

FIELD OF THE INVENTION The present invention relates to a specific, versatile solid fertilizer product and to a method of prescribing it.

The essence of the invention is that

2.1. an additive having several beneficial properties is added to the basic fertilizer;

2.2. the additive is administered in such a way that the resulting solid fertilizer contains the additive homogeneously distributed and fixed, i.e., the additive cannot freeze or segregate when frozen in the granules.

3. The most important of the clay minerals are bentonite (montmorillonite), illite, attapulgite, kaolinite, vermiculite, chlorite, etc.

4. Special additive can be mixed into various fertilizers. These fertilizers can be single or complex fertilizers.

Eligible fertilizers are: ammonium nitrate, lime ammonium salt (pethis salt), lime salt, ammonium sulphate, urea, NP and NPK fertilizers of various active ingredients, which can be prepared from melt droplets or by melt granulation.

5. The preparation of the doped solid fertilizer composition is done by selecting the last technological step prior to granulation in which a liquid phase is still present. For granulation, this may be the melt to be injected into the granulator or, in the case of a droplet process, the melt to be injected into the mixer. Of course, further additions to the melt can be added to the technology, which does not substantially affect the quality of the resulting product, but the production process will be more technically complex.

The additive is homogeneously distributed in the liquid phase with vigorous stirring. In the case of a melt, the additive must be preheated properly. The preheating temperature is determined by the thermal balance of the materials to be mixed. The additive may also be incorporated into a solid stream which is also to be added to the melt (such as a "retour" granulation or dripping process or, in the case of NPK fertilizers, various K-salts, Mg-salts, etc., or calcium carbonate or dolomite in case of lime ammonium salt).

The homogeneously mixed additive melt enters the technological phase of the granulation. In granulation, the slurry temperature is generally 115-150 ° C. In the dripping process, the melting point determines the mixing temperature, generally at a temperature of 5-10 ° C above the freezing point. Accordingly, the spraying temperature requires a melting temperature of 130-180 ° C (this also results from the thermal balance of the materials being mixed).

After solidification of the slurry containing the additive in a homogeneous distribution or formation of the particle, the desired product is obtained. The final product is formed after other necessary operations (drying, grading, cooling, surface treatment, etc.).

6. In order to illustrate the versatile utility of the fertilizer we recommend, the known properties of the admixtures must be described in detail:

Additives (ie clay minerals) have two main properties.

6.1. On the one hand, suspending agents used in suspension fertilizers. Geled with water prevents the settling of granules in the slurry fertilizers.

6.2. On the other hand, clay minerals have a number of very valuable effects in soil, which are as follows.

6.2.1. Nutrient storage

Clay minerals are layered Ilkata of different composition and structure. There are two ways to store nutrients.

Some clay minerals are affected by moisture

EN 207 505 Β (such as montmorillonite) the gratings loosen (swell) and, for example, between the separated lamellae. K ⁺ and Mg ²⁺ ions penetrate. There, they are adsorbed interchangeably until the swelling persists. When the soil (mineral) dries, the swelling of the crystal also ceases and the ions trapped between the lattice become so strongly attached that they cannot be replaced. When exposed to moisture again, the layer gratings expand again and the mineral, e.g. potassium is readily released.

The surface adsorption of clay minerals is more significant. Soil colloids have a negative electrical charge (this electrokinetic charge is called zeta potential). They preferentially adsorb cations on their surface, that is, cations entering the soil or fertilizer solution displace previously adsorbed ions in equivalent amounts. Thus, ions that play an important role in plant nutrition can be adsorbed; such as K ⁺ , Na ⁺ , Ca ²⁺ , Mg ²⁺ , Al ³⁺ and NH ₄ ⁺ cations, trace element cations, and phosphate, silicate and carbonate anions.

Ammonium ion adsorbs very well and this is an important fact for the ammonium fertilizers released into the soil. For example, the ammonium nitrate dissolves and adsorption of the physico-chemical cation occurs. The NH ₄ ⁺ ion binds to the colloid and forms a salt in the nitrate anion solution with Ca ²⁺ or Mg ²⁺ (ions) or other cations in the soil or separated by cation exchange. Similar exchange adsorption occurs eg. also for potassium salt. The adsorbed ammonium or potassium ions can be well absorbed by the plants.

6.2.2. Reduction of nutrient leaching

Soil colloids, while adsorbing on their surface or inside the silicate layers themselves by adsorption, also prevent their leaching. Particularly for sandy soils, this effect is significant because it prevents the leaching of the fertilizer applied and clay colloids retain nutrients in the root zone.

6.2.3. Improvement of water management

Soil water management depends on the quantity and quality of clay minerals. Hygroscopic clay minerals with high water capacity bind water to their surface in the form of hydroxonium ions, thus increasing the water retention capacity of the soil.

Clay soils can store 4-5 times as much moisture as the uptake by plants (pF = 2.7-4.3) than sandy soils. For example, running sand can hold up to 10% by volume of water, twice that of sandy soils with clay minerals.

6.2.4. Improvement of soil structure

Clay minerals can also significantly improve soil structure. Adhesion and aggregation of colloidal particles depends on the zeta potential of soil colloids. Particularly in case of adsorption of divalent ions (Ca ²⁺ , Mg ²⁺ ) there is a very good aggregating effect. In particular, sandy soils and loose soils can be used to improve the soil structure of clay minerals.

6.2.5. Buffering effect

The clay soil behaves like a buffered weak acid. Hydrogen and aluminum attached to the clay colloid form the potential acidity, while the dissociated H ⁺ ion forms the active acidity. If the active hydrogen is neutralized with alkali, the equilibrium will be restored and some of the H ⁺ ions in the clay will dissociate. Conversely, when H ⁺ ions are added to the system, some of the H ⁺ ions are adsorbed with the release of other cations and the soil pH is reduced. Because the soil colloids tend to adsorb or transfer H ⁺ ions to maintain the described equilibrium, the soil is able to withstand sharp pH changes, i.e., has a buffering effect.

6.2.6. Retard effect

There is a dynamic balance between nutrients dissolved in soil moisture and nutrients adsorbed on the colloidal surface. On the one hand, it enables the storage of nutrients entering the soil through fertilization, and on the other hand, it inhibits the formation of too concentrated concentrations of soil solution.

Colloidal bound soils have higher adsorption capacity and can be fertilized with high-speed, high-volume fertilizers as no harmful soil solution is formed and the colloids are bound to nutrients by the plants. The adsorbed ions are relatively more difficult to absorb for the roots than in the aqueous solution of nutrients; but remain accessible to plants. However, in absolute terms, adsorbed ions can also be readily absorbed by plants because of the loose binding force upon adsorption.

6.2.7. Root development

The effect of depth placement of nutrients and water-containing colloids on root development is not negligible. Due to the favorable conditions in the deeper layers, the root system penetrates deeper, which also increases the resistance of plants to drought. Of course, the listed beneficial effects of clay minerals are inseparable, all strongly related to the physico-chemical behavior of clay colloids.

HU 207 505 Β

7. The use of the fertilizer composition we recommend can take two forms.

7.1. In the form of solid fertilizers: In this case, the additive contained in the fertilizer is as described in 6.1. except for the benefits described in Section 6.2.1 to 6.2.7. Its application is no different from that of solid granular fertilizers, but its agrochemical effect is incomparably better than that of conventional fertilizers. In this case, it is advisable to adjust the amount of additive to be 5-20%, preferably 8-12%.

7.2. In the form of liquid fertilizers: In this case, in addition to the beneficial agrochemical effects, the clay mineral used as an additive

6.1. also has the advantage described in point.

7.2.1. If the basic fertilizer also contains water-insoluble matter, it must be suspended in the fertilizer solution, i.e. the suspension must be stabilized. In this case, the doped fertilizer component already contains the stabilizing clay mineral.

If only the stabilizing agent is to be expected from the additive, it is sufficient to blend the fertilizer with 2-5%, typically 2-3% stabilizing agent. Of course, if other agrochemical effects are desired, the amount should be adjusted to between 5-20%, preferably 8-12%.

7.2.2. If the basic fertilizer does not contain water-insoluble matter, a solution fertilizer is obtained after the aqueous dissolution. In this case there is no need for a stabilizer, the clay mineral only has to float itself. In this case, only the beneficial agrochemical effects of the additive are required. The amount of the additive here is preferably 5-20%, preferably 8-12%.

8. The agricultural application of the diluent fertilizer composition has many benefits due to the beneficial properties of the admixture. All useful properties of the additive are also valid in the added fertilizer.

When using the doped fertilizer composition, the colloidal solution of the fertilizer solution and the clay are not left to chance, but the two agents are assigned in optimum proportions. This is particularly important for soils with little or no clay content (eg sandy soils).

8.1. Fertilizers are only partially utilized when they enter the soil, ie only part of the nutrient input into the plant is involved in the structure of the plant and the rest is wasted. In the most important three macronutrients (N, P, K) the loss is 5-10%, but according to some authors it is 40-50%.

Clay minerals are capable of adsorbing the active ingredients in the fertilizer and thereby significantly reducing losses.

8.2. By reducing fertilizer losses, we not only reduce the material damage caused by lost fertilizer or plant failure, but also reduce pollution.

As a chemical, non-utilized fertilizers damage the biotic factors of the soil. During leaching, chemical substances (in many cases toxic substances, such as nitrates), when released into groundwater or surface water, are very hazardous to the environment. In this respect, the additive fertilizer composition can be considered environmentally friendly.

8.3. The additive incorporated into the diluent is a reversible water absorber, which creates a hydrogel state in its environment, and its ability to drain is also an important feature. The irrigated water causes the gel state to increase, thus preventing the water from falling to a depth of 6-40 or 40-80 cm (depending on the depth of fertilizer application).

This keeps the nutrients and water in the root zone in a form that can be taken up by the plants. Since water does not enter deeper layers, groundwater contamination is also reduced. In drought-dry weather, this phenomenon delays or bridges the lack of water in the plants.

8.4. Other advantages described in the properties of the additives include the added fertilizer composition, such as the buffering effect, the soil-wetting effect, and the nutrient-delaying effect.

8.5. The widely used slurry fertilizer manufacturing technology generally involves a rather time-consuming, device-intensive step. This is the so-called suspension stabilizer. preparation of pregelatine.

The additive fertilizer composition contains a homogeneous distribution of the clay mineral used as a stabilizer. Thus, the preparation of a slurry fertilizer simply involves dissolving the doped fertilizer in water at the point of direct application. The use of this type of fertilizer saves considerable money by eliminating certain equipment in the manufacture of slurry, reducing the time and labor involved in manufacturing it, and reducing transport costs, since aqueous mixing has to be carried out directly at the point of use.

9. The following examples illustrate the method and composition of the various fertilizers produced by the process of the present invention.

Example 1 8 kg of bentonite heated to 80-100 ° G were added to a melt of 1: 1 nutrient ratio 170-180 ° C.

EN 207 505 Β with vigorous stirring. (Propeller mixer RPM 700-900 RPM).

The initial 1: 1 ratio of NP is:

NH ₄ NO ₃ 54.851%

NH ₄ H ₂ PO ₄ 19.801% (NH ₄ ) ₂ HPO ₄ 2.201%

CaHPO ₄ 17.101% inhaled [CaF ₂ ; Ca ₃ (PO ₄ ) ₂ ; SiO ₂ etc.] 6.40t%

H ₂ O 0.651%

The 100 kg fertilizer obtained after mixing has a nutrient ratio of N: P ₂ O ₅ = 1: 1.03 and an active ingredient content of 19.98% N and 20.54% citric soluble P ₂ O ₅ .

Example 2 10 kg of kaolinite heated to 80-100 ° C were added to a melt of NP at 170-180 ° C with a 2: 1 nutrient melt under vigorous stirring. (Propeller mixer RPM 700-900 RPM.)

2: 1 ratio of starting NP:

NH ₄ NO ₃ 71.81% nh ₄ h _{2 after 4} 12.11% (NH ₄ ) ₂ HPO ₄ 1.3% CaHPO ₄ 10.41% inert [CaF ₂ ; Ca ₃ (PO ₄ ) ₂ ; SiO ₂ , etc.) 3.81% H ₂ O 0.61%

This results in:

N = 24.15%

P ₂ O ₅ = 12.241% (citrate soluble) fertilizer with a nutrient ratio of 2: 1.01.

EXAMPLE 3 5 kg of attapulgite heated to 80100 ° C were added to a kg of urea melt at 130-140 ° C with vigorous stirring. (Propeller mixer RPM 700-900 RPM). The composition of the starting urea melt:

urea 99.7%

H ₂ O 0.3%

The urea fertilizer obtained after mixing has a nitrogen content of 43.7%.

EXAMPLE 4 8 kg of calcium carbonate heated to 80-90 ° C and 12 kg of illite heated to 80-100 ° C were mixed with 175 kg to 180 ° C of ammonium nitrate melt with vigorous stirring. (Propeller mixer RPM 700-900 RPM)

Initial Ammonium Nitrate Melt Composition: NH ₄ NO ₃ 99.61%

H ₂ O 0.4t%

The N-active ingredient content of MAS-28 fertilizer obtained after mixing was 281% (petis salt).

EXAMPLE 5 2 kg of pre-treated bentonite heated to 80-100 ° C was added to kg of NPK melt at 1-1: 1 at 170-180 ° C with vigorous stirring. (Propeller mixer RPM 700-900 RPM).

The initial NPK 1: 1: 1 composition is:

NH ₄ NO ₃ 39.741% nh ₄ h _{2 after 4} 14.61% (NH ₄ ) ₂ HPO ₄ 1.621% CaHPO ₄ 12.621% inert [CaF ₂ ; Ca ₃ (PO ₄ ) ₂ ; SiO ₂ ] 4.721% H ₂ O 0.481% Potassium salt (containing 60,5% K ₂ O, mainly KC1- salt) 26.21%

The 100 kg fertilizer obtained after mixing has a nutrient ratio of N: P ₂ O ₅ : K ₂ O = 1.0: 1.02: 1.01 and an active ingredient content of 15.44% N; 15.76% w / w P ₂ O ₅ and 15.64% w / w K ₂ O.

Example 6

19.32t of 110-120 ° C NP solution containing 20% water, 5.54% of 80-100 ° C potassium salt, 4t of 80-110 ° C illite and 75 140-60 ° C 1: 1: 1 NPK product (which is identical to the fertilizer composition of the example) in the melt granulator for approx. The mixture is stirred at 125-138 ° C. The resulting material was dried to a water content of 0.5%, and a particle size below or above 75 t was screened.

Composition of the stock NP solution:

NH ₄ NO ₃ 43.361%

NH ₄ H ₂ PO ₄ 15.951% (NH ₄ ) ₂ HPO ₄ 1.771%

CaHPO ₄ 13.77% [CaF ₂ ; Ca ₃ (PO ₄ ) ₂ ; SiO ₂ ] 5.151% water 20.01%

Potassium salt is a salt containing 60.5% K ₂ O, mainly KC1.

In the 25 t fertilizer obtained after mixing, drying, and sorting, the nutrient ratio was 1.0-1.04-1.01; and an active ingredient content of 13.241% N; 13.831% P ₂ O ₅ and 13.4t% K ₂ O.

Claims (3)

PATIENT INDIVIDUAL POINTS A doped solid fertilizer composition, characterized in that (i) 80-98% by weight of the known fertilizer N, NP, NPK and fixed in the fertilizer homogeneously distributed and fused with melt, (ii) 100% by weight It contains from 2 to 20% by weight of natural minerals. Composition according to claim 1, characterized in that (ii) contains clay minerals (e.g. bentonite - montmorillonite - and / or illite and / or attapulgite and / or kaolinite and / or vermiculite). A process for producing a solid fertilizer composition according to any one of the preceding claims, characterized in that component (ii) is homogenized in molten (i) fertilizer, preferably in the last liquid phase prior to solid particle formation.