HU201508B - Process for freeing of acid influence of fertelizer and assuring of regulated deposition of the active substance - Google Patents

Abstract

The present invention relates to a method of reducing the acidifying effect of fertilizers and providing a controlled release of the active ingredient, wherein a particulate lime fertilizer composition having a diameter of 0.1 to 4 mm is provided, which is provided with a bark. The essence of the method is to make the bark layers on the core such that the core, in a manner known per se, is 20-95% of the total weight, and the layered bark is 80-5% of the total weight. The individual layers are formed so as to eliminate their continuity and the discrete porous and / or sheet and / or filamentous layer (s) thus formed contains (or contains) calcium, or at least a portion thereof, providing the lime content. 00 o CM o CM Scope of description: 4 pages, without figure -1-

Description

FIELD OF THE INVENTION The present invention relates to a method for reducing the acidifying effect of fertilizers, wherein the release is controlled and preferably the order of release is ensured. The solution is expediently applicable to crop production processes and its use can achieve environmentally friendly nutrient management.

Worldwide, efforts are now being made to intensify crop production processes as much as possible. It is known that this goal in the field of nutrient management can only be achieved by regulating nutrient ratios, high fertilization and respect for the environment.

However, it is also known that commonly used fertilizers have an acidifying effect and thus their use has an adverse effect on soil pH. This effect, in turn, is known to reduce the effectiveness of macro and microelements.

Experimental results in Hungary show that a 25% decrease in yield and a 20% decrease in fertilizer efficiency can be expected on our acidic soils in the coming years. Since 1980, the pH of our soils has decreased by about 0.5, and a quarter of the country's total area belongs to the acidic category.

As a result of the above, the application of liming materials to cultivated soils is essential. Natural rocks are available for meliorative interventions and industrial by-products are also used. The application of acidifying agents is generally performed as a meliorative intervention. Hungarian Patent Specification No. 194,144 discloses granular lime fertilizers for the treatment of acidic soils, which are known to provide the necessary lime replacement.

In order to reduce the operating costs and to interact with the fertilizer, it is advisable to apply at least a part of the lime needed for the soil and the fertilizer in one pass during the meliorative intervention.

One way to simultaneously apply fertilizer and basic materials is to coat the fertilizer particles with a material that can dampen the acidity of the soil. For example, bituminous mineral oil in colloidal form is used to improve the physical properties of urea. A known solution is, for example, U.S. Patent No. 3,313,613, which dampens the surface of urea with aqueous formaldehyde, to which a separate sulfur powder is applied, to extend the degradation time of urea. Hungarian Patent No. 190,798 describes blending with urea, melt dolomite, or limestone powder. At high temperatures - approx. 130 ° C - Toxic biuret is formed on plants. There are several known methods for mixing ammonium nitrate in limestone, dissolved or melted in water, at high temperature. The purpose of these known methods is to eliminate the adherence by adding the calcium nutrient.

Hungarian Patent Application No. 168,235 discloses the production or coating of fertilizer granules by fluidization process in a continuous operation apparatus.

It is also known to produce lime-containing fertilizers consisting of solid seeds and bark for the treatment of acidic soils. This known solution requires the use of a fraction of the additive having a particle size of less than 100 or less than 50 μg.

U.S. Patent No. 2,660,541 describes the coating of ammonium nitrate with Na-silicate, while French Patent No. 1,519,208 discloses the application of a mixture of borax and octadecylamine solution to urea particles.

, Dry Mixing of Fertilizers ”. (Agricultural Publishers, Budapest, 1980) describes the application of water soluble micronutrients to fertilizer granules. According to the method, the trace elements are dissolved in a fertilizer solution and the solution is applied to the surface of the granulate.

U.S. Patent No. 3,059,379, U.S. Patent No. 3,159,469, which is also a polystyrene, and U.S. Patent No. 3,259,489, provide a solution for the manufacture of a polyethylene fertilizer packaged in polyethylene.

The disclosed solutions describe processes in which coatings reduce the rate of dissolution of the active ingredient and some of which are known for treating acidic soils. The known solutions do not provide a controlled rate and sequential release of fertilizer from the grain. In general, these solutions comprise a core having a diameter of 0.1 to 4 mm produced in a manner known per se, to which a specific layer, such as a lime replacement layer according to Hungarian Patent Application No. 194,144, is applied. Known solutions include two layers of the core - see, for example, U.S. Patent Nos. 3,392,007 and 3,419,379, and English Patent No. 815,829, where the purpose of applying an additional second layer is a coating layer. or creating a protective layer.

Much of the literature deals with solutions to reduce the rate of dissolution of fertilizer grains, while other known solutions provide solutions for the lack of basic material in the soil. A disadvantage of the known solutions is that the possibility of replacing the basic material and controlling the dissolution rate of the fertilizer active ingredient is not ensured at the same time.

SUMMARY OF THE INVENTION The object of the present invention is to provide a process which avoids the acidifying effect of a fertilizer known per se and which also provides a controlled release of the active ingredient.

The present invention is based on the discovery that when the fertilizer grain is layered, the so-called fertilizer grain is so-called. If the onion skin is structured, the release can be controlled according to the number and order of the layers, and the desired order of release can be determined.

Experiments have been carried out which have found that it is desirable to apply a bark consisting of layers where the ratio of the total weight of the core to the bark is 20-95% of the total weight of the core, known as 0.1-4 mm. 80 to 5% of the bark consisting of layers, where each layer is formed so that it is discontinuous, but discrete - porous and / or lamellar and / or filamentous - which allows control of the core and

EN 201508 Release rate of the inner contents of each layer. It has also been found that the soil acidifying effect of the fertilizer is best mitigated when the discrete layer (s) contain at least a portion of the required calcium bound to humic acid. An important element of our solution is the use of humic acid derivatives, since humic acids, with calcium-containing additives, form calcium-humate, which are the adhesives of soil particles and their role in the formation of soil structure. In addition, organically bound calcium is not leached and thus provides the plant with a safe supply of calcium.

FIELD OF THE INVENTION The present invention relates to a process for reducing the acidifying effect of fertilizers and providing a controlled release of the active ingredient by providing a core having a diameter of 0.1 to 4 mm, which is provided with a crust. The essence of the process is to form a granular lime fertilizer composition by making the crust on the core in layers such that the core is 20-95% of the total weight and the crust consisting of layers is 80-5% of the total weight. The individual layers are formed by removing the continuity of each layer and the discrete layer (s) of porous and / or lamellar and / or filamentous form thus formed, containing at least a portion of the calcium providing calcium, or humic acid. ) za.

In a preferred embodiment, the crust consisting of discrete layers is an adhesive, preferably 1 to 40% of the total weight, and / or is biologically active and / or basic material having a particle size of less than 50 µ.

In a further preferred embodiment of the process, the adhesive is a nature-friendly macromolecular material, preferably CMC. (= Carboxymethyl cellulose)

Preferably, lignite powder and / or carbon black powder is used to form the discrete layer (s).

In the process, any finely divided basic material, preferably limestone powder, dolomite powder, marsh lime, lime sludge, filter powder, can be used in the lime fertilizer composition.

The process of the present invention will be described in detail with reference to the following examples, without limiting the scope of the invention to these examples.

Example 7

To a 1200 g urea fertilizer with a grain size range of 1-3 mm, 600 g granulation powder containing 7% CMC powder is mixed. The granulation powder contains a cement powder filter powder with a particle size of 10-50 μ.

With stirring at 0.3 ° C, 0.3 dm ^{2 of} granulating solution are sprayed in portions, which is a saturated solution of urea and CMC. Intensive mixing of the granulating solution and the powder produces homogeneous, non-adherent 30% N containing calcium and magnesium fertilizers.

Example 2 Part of urea was mixed with 3 parts of limestone powder containing 80% CaCO3 in a turntable mixer, to which 1/9 parts of CMC powder was continuously added. Prior to mixing, the urea solution is mixed with CMC fluff and the resulting suspension is continuously watered to the fertilizer with vigorous stirring. The mixing progresses continuously, the individual ingredients are fed at the above ratio. The tilt angle of the agitator plate is adjusted so that urea particles which reach a certain weight and thus take up the required amount of additive can be continuously discharged from the plate. Thus, urea with a particle size distribution of 1-4 mm results in a product having a uniform particle size, which is experimentally 5-6 mm.

The water used to form a uniformly fine carbonate layer, up to 8% of the finished product, can be removed without the use of hot air and stored outdoors. The finished product is a 10.9% N, 29% CaO, solid-coated, well-stored, dispersible fertilizer.

Example 3 5 tons of ammonium nitrate is coated with a limestone coating. N-fertilizer has a grain size range of 0.1 to 5 mm, which further increased the dustiness of the product.

The first mixing drum is introduced into a 1 m beveled axle mixing drum, in which 0.42 tons of fertilizer is mixed with 0.24 tons of cement powder and 20 kg of CMC powder with continuous mixing.

In addition to the above, the previously prepared suspension, which is a saturated solution of ammonium nitrate and contains CMC flakes in an amount of 20 kg, is continuously added to the mixture in an amount of 0.13 tons.

Addition is done in continuous operation. The tilt angle of the mixing drum must be adjusted so that the additive theoretically calculated for the required N and CaO content forms a uniform coating.

In our experiment, the optimum residence time in the mixing drum was obtained at an angle of 40 ° to the horizontal,

In spite of the mixed particle size of the ammonium nitrate raw material, the finished product is a high quality fertilizer of uniform size. Its nitrogen content was 28% and its CaO content was 13.5%.

Of the 5 tonnes of ammonium nitrate fed, 8.2 tonnes of finished product were produced, with a 4% post-production water content that did not adversely affect shelf life. Some of the moisture has been removed in the finished product storage.

Example 4

In the apparatus described in the preceding paragraph, a mixed fertilizer is formed. We aim to create a popular 3x16% NPK composition for spring basic and head fertilization, and the calculated finished product is 1 ton.

The material to be coated is urea having a particle size range of 1 to 4 mm. Monoammonium phosphate and potassium salt fertilizer are used as additives.

As described in the previous point, the mixing drum is loaded with the CMC portion of urea and powder needed for the first mixing, followed by the addition of a mixture of separately suspended MAP, potassium salt and CMC flakes. The significance of the experiment is due to the fact that the MAP and powdered potassium salt of the commercially available powder are coarser than the additives used in the previous examples,

EN 201508 The product is in the range of 0.1-1 mm. Due to the properties of the raw materials, a sufficiently stable coating required more wetting and bonding.

A total of 290 kg of urea was used, 315 kg of MAP and 275 kg of potassium salt powder were added, and 72 liters of water were required with 30 kg of CMC powder and 20 kg of flakes to form a stable granule form.

The three nutrients (NPK) were present in the finished product in a ratio of 16.6: 16.6: 16.6%. The product naturally did not take a uniformly round shape, but visual inspection and analytical nutrient testing confirmed that the 30 minute mixing time per tonne was sufficient to produce a homogeneous, well-bound granule.

Example 5

Like nitrogen fertilizers, potassium salt has an acidifying effect. It therefore seems desirable to limit the pH-lowering effect of the most widely used granular potassium salt at the same time as application. Dolomite powder was used as an additive in the experiment. An aqueous solution of the 0-80 micron particle size fraction of dolomite, mixed with CMC, was applied to the potassium salt pellet with a size of 1-3 mm as described above.

2/3 parts of granulated potassium salt and 1/4 parts of dolomite powder were added to the finished product with the addition of a suitable proportion of CMC glue and water.

The final product contained 40% K ₂ O, 5.3% MgO and 7.3% CaO. The storage properties of the material have improved significantly compared to the original material.

Example 6

According to Example 2, 1 part of urea is mixed with 2 parts of limestone powder containing 80% CaCO3 in a turntable mixer, to which 1/9 parts of CMC powder is continuously added. A mixture of CMC (2.5%) and K-humate (10%) solution is saturated with urea and the first discrete layer is formed in a manner known per se. The second layer is prepared as described above with an additional 1 part of limestone powder containing 80% CaCO3 and the adhesive solution described above. In this way, a two-layer fertilizer consisting of 10.9% N and 29% CaO, which is easy to store and spray, is produced.

Example 7

As described in Example 6, the formation of the second layer was accomplished by the addition of 0.5 parts CaCO3 limestone powder and a 10% solution of K-humate in urea. After compaction of the second layer, a discrete porous layer was prepared with 0.5 parts of carbon black powder having a particle size of less than 50 μ and the adhesive solution of Example 6. The process produces a three-layer fertilizer containing 10.9% N, 20% CaO and 10% carbon.

Example 8

In the same manner as in Example 4, 315 kg of potassium salt is first applied to urea particles having a grain diameter of 1 µm and then 290 kg of monoammonium phosphate is applied to the compacted layer on the already known cane. This layer is coated with a third silica gel layer, which inhibits phosphorus binding in the soil, to which the fourth layer is formed by applying 300 kg of carbon dust and glue solution together. Thus, a four-layer fertilizer that is easy to store and spray is obtained.

The granular lime fertilizer formulations produced by the process of the present invention serve the intended purpose, mitigate the acidifying effect and provide a controlled release of the active ingredient. The discrete layer (s) prepared according to our solution - preferably 1-15 layers of bark, granular structure fertilizer with good grain strength and can be used for various fertilization purposes such as starter, nest, row fertilization.

Claims (5)

PATENT CLAIMS CLAIMS 1. A method of reducing the acidifying effect of fertilizers and providing a controlled release of the active ingredient comprising providing a granular lime fertilizer composition comprising a core having a diameter of 0.1 to 4 mm, wherein the bark on the core is 1-15 pieces. is made from a layer such that the core, in a manner known per se, is 20-95% of the total weight, and the bark consisting of the layers is 80-5% of the total weight, and each layer is formed so as to break its continuity and so trained discreet - porous and / or lamellar and / or filamentous - the layer (s) containing calcium or at least a portion thereof providing the limestone bound to humic acid. Method according to Claim 1, characterized in that the crust consisting of discrete layers is an adhesive, preferably 1 to 40% of the total weight, and / or a biologically active substance and / or a basic substance having a particle size of less than 50 µ. The process according to claim 1 or 2, characterized in that the discrete layer (s) is formed by using lignite powder and / or carbon black powder. A process according to claim 2 or 3, characterized in that the adhesive is a nature-friendly macromolecular material. The process of claim 4, wherein the macromolecular adhesive is preferably CMC or a humic acid derivative.