Abrasion-resistant fertilizer and method thereof

 

(57) Abstract:

The invention relates to a fertilizer, which is a composition with a coating of sulfur, which is applied to the polymer. The invention consists in that the top coating on a coated with a layer of sulfur fertilizer contains about 5-50 wt.% polymer and 95-50 wt.% hydrocarbon wax, and as the polymer used copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylic acid, copolymers of ethylene and ethyl acrylate, copolymers of ethylene and vinyl alcohol, terpolymer ethylene, vinyl alcohol and vinyl acetate or mixtures thereof, and a hydrocarbon wax selected from the group comprising natural oil paraffin wax dropping point 60-80oAnd synthetic hydrocarbon wax having a melting point 60-105C and mol. the weight of 400-600, or mixtures thereof. Fertilizer has the ability to slow the secretion of substances, wear resistance, flowability, does not stick together and essentially dust-free. 2 C. and 12 C.p. f-crystals, 5 PL.

This application is a partial continuation of pending application U.S. 08/074141 from 09.06.93, which in turn was a continuation application 07/655157 from 14.02.91, now withdrawn.th applied polymer resistant to abrasion, loose, nokiausers, essentially dust-free, with improved ability to slow the release of substances.

The method of coating of sulphur in granular or lump fertilizer was developed in 1968 Tennesse Valley Authority (TVA) Muscle Shoals, Alabama, as a cost-effective way to reduce the dissolution rate of the particles of urea when introducing them to the soil as fertilizer. In the literature [1] described such a method of applying a coating of sulfur, as well as sealing material required to fill the channels, cracks or defects that are formed, as a rule, in the coating of sulfur when it is cooling. The way TVA also described in the literature [2-4]. In accordance with this method is recommended for use as a sealing material, a mixture of 30% polyethylene resin in 70% mineral oil "bradstock". In detail the method described in the literature [5].

The necessity of using sealing material while getting covered in grey urea (PSM) has been confirmed in the literature [6,7].

Description urea and nitrogen-phosphorus-potassium fertilizer with a slow release of substances found in the literature [8].

For relatively slow rastvortsev to the coating of urea, and involves the dissolution or dispersion of urea in wax, as described in the literature [9].

Due to low Edgley paraffin is not used in pure form as a cover to obtain fertilizers, such as urea, with a low rate of release of substances. For this reason, the material used for the coating is covered with a grey fertilizers, for example, covered with a grey urea (PSM), and also because such coverage is erased or cracks or wear when performing operations in devices with high speed layer, in cases where large quantities are transported using a hopper or open platforms and then unloaded into the storage silos. Paraffin-oil sealing material, as specified in the TVA publications and as currently used for PSM requires you to add the clay conditioning agent in amounts approximately equal to the number of paraffin sealing material to prevent clumping and obtain a free flowing product. In accordance with the method usually requires 3% of paraffin-oil sealer and 2% clay conditioning agent from the mass PSM, or 67% clay, the addition to equipment for applying molten sulfur and paraffin seal.

When the conditioned clay PSM contribute to the field by mechanical spreaders, remove clay or a mixture of paraffin with clay particles PSM under the action of friction screw conveyors and wheel mechanical spreader, which leads to the accumulation of a mixture of paraffin with clay in various parts of the mechanism and requires frequent stops to clean them.

An additional problem associated with the use of PSM obtained by known methods, is the reduction or loss of water-insoluble nitrogen (NCA) during transportation of the product from its place of production to the place of preparation of the mixture. These losses are compounded by further abrasion occurring during preparation of the mixture and packaging bags. After mixing and bagging urea and mixed fertilizer with a slow release of substances must be marked in accordance with the content of the SOA, the manufacturer is responsible for ensuring that specified on the label values are not dropped during transport and storage. Thus, significant losses NCA when using modern high-speed equipment can lead to a situation in which the fertilizer will be n obrinje, coated with a mixture of wax and resin, and the coating is deposited directly on the surface of the fertilizer, not fertilizer, covered in grey.

In the literature [11] described fertilizers with a polymer coating, where the polymer coating contains a copolymer of ethylene with carbon monoxide as a mandatory component. The coating may also contain other resins, including koutsokoumnis resin, for example, natural rubber, polyisoprene, polybutadiene and other or a copolymer of ethylene with vinyl acetate. However, in this case, the polymer is also applied to the fertilizer without the sulfur coating.

In the literature [12, 13] described the use of standard coatings by the method of TVA deposited on the particulates coated with sulfur. In accordance with both of these references the outer coating is relatively soft and fluid when the ambient temperature so that the material acts as a sealant to fill cavities, cracks or defects present on the surface layer of sulfur. In this literature do not describe the use of non-leaking exterior coatings applied on the coating of sulfur. Moreover, these materials must be made in the layer of sealant or coating on top of it powder covered synthesised material condi(a) inner core, representing solid granule fertilizer, (b) the sublayer adjacent to the inner core of the fertilizer granules, and (C) a coating of elemental sulfur, essentially completely kapsulirujushchuju granule fertilizer coated with a sublayer. The underlayer located between the core of fertilizer and a coating of sulfur necessary to achieve the desired result and contains a fine powder, for example, charcoal or soot, is capable of reducing the contact angle between the surface of the fertilizer granules and an outer coating of sulfur.

In the literature [15] described a method of producing fertilizer with slow release, covered with extremely gray, and the invention aims to eliminate the need to apply a layer of sulfur second coating or application of sealer.

The main task of the present invention to provide resistant to wear or abrasion bulk of nokiausers essentially dust-free fertilizers, covered in grey with an outer layer of polymer, which has an improved ability to slow release of nutrients.

Another object of the invention is the coating on the coated grey fertilizers and other substances dlakave or granular fertilizer with a low and uniform release rate into the soil of nutrients for the plants over a long period of time.

Another object of the present invention is to provide a coating that can be easily applied in the form of a melt is covered with a grey particles of fertilizer and production of fertilizers with reinforced coating of sulfur, which is not sticky and free flowing when cooled to ambient temperature and therefore does not require the use of large amounts of clay or other conditioning agents and minimizes the buildup of deposits on the equipment fertilizer into the soil.

Another object of the present invention is to provide a polymer coating for coated grey fertilizers, ensuring the achievement of high values of NCA, which did not decrease significantly due to wear occurring during transportation, shifting, packaging bags and storage.

In particular, it was found that granules or pieces of fertilizers coated with sulfur in accordance with the methodology developed by TVA, and then covered certain hydrocarbon wax-polymer composition, allow to obtain a wear-resistant fertilizers or their components with a low rate of release of soluble nitrogen in the soil.

The wax-polymer compositions prigotovlyayut groups in side chains, with some hydrocarbon waxes.

As the basis for compositions with delayed release of substances in accordance with the present invention can use a number of different forms of fertilizers in the form of pellets, lumps and other particles. For example, the particles may constitute crystals, grains, flakes, tablets, etc., As a rule, the floor is easier to apply if the form of essentially spherical. Preferred particles of such sizes that pass through a 4 sieve mesh, but do not pass through 20 mesh.

Substances for the plants, which are used as a basis, as a rule, consist of nitrogen, phosphorus and potassium, but may contain small quantities of other components. Fertilizers that can be used include, for example, ammonium sulfate, ammonium phosphate, urea, superphosphate, dicalcium phosphate, basic calcium phosphate, potassium sulfate, potassium phosphate, potassium chloride, magnesium oxide and magnesium sulfate. Can also be cooked in various mixtures of these compounds, for example, coatings can be applied to mixed fertilizers, available in a large number of sales.

Particularly preferred polymers for use the links to vinyl acetate is preferably from about 20 to 2, and molecular weight is in the range from about 2000 to 20000, and copolymers of ethylene with acrylic acid, including cincinelli of ethylene and acrylic acid, in which the mass ratio of ethylene units to the units of acrylic acid is most preferably approximately from 50 to 10, and the molecular weight is in the range from about 2000 to 20000.

Examples of other resins that can be used are copolymers of ethylene and acrylate, copolymers of ethylene with vinyl alcohol and terpolymer ethylene, vinyl alcohol and vinyl acetate.

Particularly preferred hydrocarbon waxes that can be used in the present invention are natural oil or mineral waxes, containing less than 5% oil, having a melting point in the range of from about 60 to 80oC, and in which essentially no aromatic and cyclic structures, and synthetic hydrocarbon waxes, which melt in the range of from about 60 to 105oC.

Examples of waxes suitable for use in accordance with the present invention are paraffin wax and microcrystalline wax. Solid paraffin Go usually referred to as petroleum distillate, or when the hydrocarbon synthesis by low temperature hardening and squeezing pressing or by solvent extraction. He is in solid form at room temperature and deformation at this temperature is very insignificant, even under significant pressure, and has a low viscosity (35-45 St)oC (200oF) in the molten state. Microcrystalline waxes have a molecular weight in the range from 400 to 700, with one molecule in average contains from 40 to 50 carbon atoms. They are characterized by a high proportion of side chains and a large number of cyclic hydrocarbon chains.

In accordance with the present invention paraffin-polymer compositions are applied to the coated gray granules or pieces of fertilizers in the amount of from 0.75 to 10%.

Thus, were found resistant to abrasion or wear loose neslepauline essentially dust-free fertilizer with a coating of sulfur with an outer layer of polymer and obtained by mixing from about 5 to 50% of the hydrocarbon soluble polymer with a hydrocarbon wax. Preferred polymers are selected from the group resinous polymers which impart stickiness and adhesion of the hot melt, the question can eliminate the blocking effect.

Used in the present invention, the polymers and copolymers are soluble in a wide range correlations in paraffin hydrocarbons with obtaining compositions having a melting point below about 105oC, preferably below 90 and most preferably from about 60 to 85oC.

Suitable for use in this invention are copolymers of ethylene and vinyl acetate to produce and sell many firms. These include ELVAX resin manufactured by DuPont, a series of resins A-C 400 manufactured by Allied Corporation, resin ESCORENE manufactured by Exxon Chemical Company, resin ELVACE production Reichhold Chemicals Inc. and EVA copolymers production Union Carbide Chemicals and Plastics Company Inc. The vinyl acetate content is about 5 to 30 wt.% by weight of the copolymer. When the vinyl acetate content is less than 5% of the copolymer does not cause a significant improvement in the adhesion properties of the outer sealing coating, and when the vinyl acetate content of greater than 30%, the resulting copolymer is incompatible with paraffin hydrocarbon part of the sealing mixture.

The copolymer should have a molecular weight that the melt viscosity of the mixture of the copolymer with a paraffin hydrocarbon was quite low, so it was easy to apply, zip in the present invention are copolymers of ethylene with acrylic acid produced by Allied-Signal Inc. and sold under the trade names A-C 540, A-C 580 and A-C 5120, as well as company the Dow Chemical Company under the trademark PRIMACOR. Suitable copolymers contain a maximum of about 10 wt.% acrylic acid by weight of the copolymer. Copolymers with a high content of acrylic acid is incompatible with paraffin hydrocarbons.

Suitable for use in this invention are copolymers of ethylene with acrylate produced by Union Carbide Chemicals and Plastics Company Inc. and sells under the trademark DPDA 9169. Suitable terpolymer ethylene, vinyl alcohol and vinyl acetate produced by Allied-Signal Inc. and sells under the trademark ACTOL 70.

Polymers modified by introduction of a sufficient quantity of hydrocarbon waxes, so that the temperature of their melting or softening was approximately 40 to 110oC, preferably from about 60 to 100oC, and most preferably from about 65 to 85oC. Suitable hydrocarbon waxes include petroleum or mineral waxes having a melting point in the range of from about 38 to 80oC. the Waxes also contain varying amounts of oil, which is usually determined by the degree of dissolution of paraffin in methylethylketone at 31,7oC (ASTM D721). Provisionsa properties is variable and determined in the specific case of the method of separation of paraffin from oil, derived from a specific field.

Preferred petroleum waxes are characterized by a point of dropping 60oC and above, the oil content is less than approximately 15%, preferably less than 5% and most preferably about less than 0.5%, of aromatic and cyclic hydrocarbons in them essentially absent. They form a much more correct crystals when cooled from the melt, which gives them a high moisture resistance, however, makes them brittle.

Examples of suitable petroleum waxes are microcrystalline waxes, which usually contain from 5 to 15% oils, crude paraffins (paraffin GAC), which usually contain from 5 to 15% oils, scaly paraffins, which typically contain from 2 to 5% of the oils, paraffin waxes, which typically contain from 1 to 2% oil, fully refined paraffins, which usually contain less than 1.5% oil.

Other suitable hydrocarbon waxes are synthetic waxes, including polyethylene waxes, for example, manufactured by Chevron Chemical Company, which sells under the trademark Gulftene C30+. It is a synthetic wax obtained by the polymerization of ethylene. The process of obtaining alpha olefin is erinacei to 10-18 carbon atoms, although the formation and longer carbon chains. Waxes suitable for use in the coatings, are remnants from the removal of the larger part of the molecules of the polyethylene chain length up to 28 carbon atoms. The usual composition of such a wax is characterized by the size of the molecules of paraffin hydrocarbons and the position of the olefinic component. Suitable for use in the present invention paraffins containing from 3 to 20% C24-28hydrocarbons, from 60 to 95% WITH30-56hydrocarbons and from 0 to 20% C56and heavier hydrocarbons. They include from 0.5 to 2% saturated hydrocarbons (containing no unsaturated bonds), from 30 to 40% of the hydrocarbons with double vinylidene links, from 8 to 12% hydrocarbons with double internal links and from 50 to 55% of hydrocarbons with double alpha bonds. The dropping point is about 71oC.

Other suitable synthetic paraffin is Polywax 500 manufactured by Petrolite. He is a polyethylene of average molecular weight 500, the dropping point is 86oC, and a viscosity of 3 CP at 149oC.

The above-described waxes differ from polyethylenes, such as produktowe hydrocarbons in accordance with the present invention are characterized by an average molecular weight in the range from 400 to 600 and form the large crystalline areas, if they melt and cool. Polyethylene is A trademark-C6 and A-C1702 have an average molecular weight of about 2000 and 1600, point dropping 106 and 92oC, respectively, and for the most part, are amorphous. Get them in accordance with different production processes.

Described here hydrocarbon waxes are preferred for use in obtaining external coatings in accordance with the present invention. The most preferred paraffin materials presented by the product Gulftene C30+.

Compositions which are solid at room temperature, the materials have a density above about 0,915 g/cm3.

Such compositions are also characterized by the absence of a blocking effect when applying them in the form of films on the basis of sulfur at a temperature of 42oC, as the test showed the following method: 10 g of the sample PSM, which was applied sealing composition was placed in an aluminum Cup, and the sample above has established a weight of 100, the Weighted sample of urea was placed in a furnace at a temperature of 42oC. After 30 min the weighted sample was removed from the furnace and left to cool at room temperature. The cargo was removed and OC the Oia with an outer coating of the composition, obtained in accordance with the present invention, does not stick together with each other with this test and remain loose when stored in bags or bins for storage.

Compositions in accordance with the present invention are characterized by a high coefficient of specific adhesion to solid sulfur. Drop the specified composition, placed in molten form on the heated surface of a solid sulfur, spontaneously spreads, with the front edge of the spreading film has an angle of 45 and preferably less than 15.

Other components that are added in small quantities in paraffin insulating coating, for example, antioxidants and supplements that suppress the vital activity of microorganisms are well known in the art and can also be preferably introduced into the composition of the present invention.

In the present invention proposed a method of applying an external coating on the coated sulfur particles fertilizers or other particles of fertilizer. The method is characterized by the absence of the compositions of volatile components, the tendency of the compositions to spontaneous spreading on the surface of the fertilizer particles, which allows to obtain a coating without voids and small holes, and what ATM to dispense particles of fertilizer.

The method consists in the implementation of the contact coating composition covered with grey fertilizer granules at a temperature above the melting temperature of this composition and stirring, sufficient for uniform distribution of the coating, and cooling with continuous stirring to ambient temperature.

A preferred variant of the method consists in placing the coated sulfur particles fertilizer disc granulator, the rotation of the drum or other suitable device for mixing solid particles, heating the particles to a temperature of about from 70 to 100oC, preferably from about 78 to 88oC, and the introduction of the coating composition in spray form, in the form of a liquid stream, or in the form of pellets or lumps with a diameter of from 0.5 to 2 mm, which is in contact with the heated pellets covered with grey fertilizer immediately melted. Covered in grey fertilizer is cooled in a rotating drum or in the fluidized bed, it becomes loose without the help of clay or other conditioning agent.

The following examples illustrate preferred compositions for the coating is covered with a grey fertilizer and preferred method ol the Scriptures all the mass percent calculated on the total weight of all components of the described compositions.

Example 1. 75 g Gulftne C30+, and 25 g of ELVAX 420 (18% vinyl acetate) were mixed, heated to a temperature of 180oC under stirring and stirred for further 30 minutes at this temperature. The resulting mixture had a viscosity of 300 to 340 CP at 125oC and the melting point 75oC.

100 g of coated grey granules of urea (1-2 mm in diameter) were placed in a heated Cup and was heated to 75oC. 2 g of a mixture of Gulftene-ELVAX molten at 80oC added in a thin stream while stirring the particles PSM. Coating composition spontaneously distributed with the formation of a uniform coating of melted wax on the particles of urea. Stirring was continued for 1 min. the Cup was removed from the heat source and continued to stir until then, until the temperature of the particles did not fall below 45oC, the particles acquired flowability.

Example 2. In accordance with the methods of example 1 were prepared and put the following songs:

A. 25% ELVAX 265 (28% vinyl acetate), 75% of Gulftene C30+,

B. 10% ELVAX 265, 90% of Gulftene C30+,

C. 25% ELVAX 265, 75% of solid paraffin, So pl. 65oC,

D. 25% ELVAX 420, 75% of solid paraffin, So pl. 65oC,

That is, 25% ELVAX 420, 75% crude paraffin,

F. 25% A-C 400A (13% vinyl acetate), 75% of Gulftene C30+,

G. 5% A-C 540A (5% akrabu TVA by mixing 70 g of Shellflex 790, which is gidrirovannoe solvent extracted paraffinic oil equivalent HVI Britestock, having a density of 0,905, the molecular weight of 600-650, a viscosity of about 3 cc (30-35 seconds universal viscosity of Saybolt at 100oC) and 30 g of A polyethylene-C6 (dot dropping 106oC). The above composition was applied in an amount of 3% granules PSM. The obtained granules are characterized by high viscosity, while it took 2 g of diatomaceous earth to give them flowability.

Example 4. The wear resistance of the granules PSM with the coating tested in accordance with the following method.

90 g of the sample covered by PSM was placed in a glass vessel (diameter of 9 cm and a length of 16.7 cm), which was closed with a lid. The vessel was laid on its side and was intensively shaken up and down so that the particles hit the wall of the vessel for 30 sec. Then measured the amount of dust (particles of yellow sulfur and wax stuck to the walls. Particles of urea, which is thus subjected to wear, were tested to determine the magnitude of the SOA, as indicated below, and the test results are compared with the results obtained for the product, not of the past wear.

To determine the magnitude nerastvorim and gently stirred in a circular motion. The vessel was closed with a lid and left for 24 h, and then again gently mixed in a circular motion and determined the amounts of dissolved urea in the refractive index of the solution. The determination was repeated after 4 days and then after 7 days. The test results are presented in percent of NCA, obtained by subtracting the dissolved part of the added quantity for the determination of residue (table. 1).

Example 5. In the drum for coating diameter 40,64 cm (16 inches) and a depth of 20.32 cm (8 inches), provided with ribs or plates every 15.24 cm (6 inches), downloaded 1 kg of granulated potassium sulfate. Used potassium sulfate produced by International Minerals and Chemical Corporation (INC) in granules, sieve number system USA -5+8 (95%), number (SGN) 275, the content of K2O is 50%. The drum was rotated at a speed of 20 rpm while heating the granules to a temperature of 80oC. the sulfur Melt was applied to the granules of potassium sulfate by means of gear pump in the form of a jet sprayed by filing it under a pressure of 10 PA (15 pounds/inch2) heated to 150oC air. The flow of sulfur, sprayed air, at a speed of about 45 g/min was sent to the granules until the number saiden the sulfur 19 wt.%.

Half the number thus obtained samples were taken on the test. The rest of immediately placed back into the same drum for applying a polymer coating when the content of polymer 3%. The application of the polymer was carried out by reheating covered in grey samples of the pellets in the drum 60oC when the rotation speed of 20 rpm On a rotating granules were poured of 38.5 g of molten (at a temperature of 125 to 150oC) polymer. As the polymer used composition of 75% Chevron Gulftene C30+ alpha olefin wax and 25% of DuPont Elvax 420 (copolymer of ethylene and 18% vinyl acetate). The temperature of the composition was maintained at a level of 65 to 70oC for 3 min, if necessary fueling. The obtained product with an outer coating has cooled in the drum 60oC and in the fluidized bed 30oC. the Cooled product was sifted through a sieve -5+10.

Thus obtained samples covered with grey sulphate of potash, with a polymer coating and without it, were tested to determine their ability to control the release of substances before and after processing, simulating their discharge, by dropping from a height of 6.1 m (20 ft) in a steel Cup. To determine the ability to control the sample in 150 ml of distilled water at room temperature. After a certain period of time all the water was poured through the filter and replaced with fresh. An aliquot of 5 ml desantirovanii water treated with urease. The selected ammonia was titrated with 0.1 N NaCl. Measured thus, the amount of nitrogen was expressed in the total percent total nitrogen, the selected time interval.

The results are given in table.2, and each value is the average of three measurements.

In relation to the table it should be noted that the results of both tests carried out for 1 hour and 7 days, the polymer coating is allowed to provide a much better ability to slow the release of substances in comparison with covered grey granules of potassium sulfate without such coverage.

Thus, the table presents data show that the polymer coating allows to obtain a product with good adjustable ability to release substances and superior durability compared with the coverage of sulfur.

Example 6. The ammonium phosphate (IAF) struck a coating of sulfur and half the number of the samples coated with the same polymer and using the same obarudavanye N-P-K, equal 10-50-0, 95% of the granules with the size -5+8, SGN 275.

The product coated sifted through a sieve -5+8. Differential dissolution rate was measured before and after unloading in accordance with the method of example 5. Results have been presented in table. 3.

Thus, the table presents data show that the polymer coating allows to obtain a product with good adjustable ability to release substances and superior durability compared with the coverage of sulfur.

Example 7. We compared the physical properties of the products obtained in examples 5 and 6, only with a coating of sulfur and polymeric coating over the coating of sulfur. The results are presented in table.4, where the parameter of wear of firmness were evaluated for dissolution rate before and after operation (flushing), the dusting was determined by the presence of dust by shaking the material by hand, no adhesion was evaluated by adhering coating on the screen.

Example 8. The ammonium sulfate was coated with sulfur and then the polymer under the conditions of example 5. As ammonium sulfate used granulate BASF, (95% of the granules -8+20), the N content of 21%.

The product is coated, sifted through a sieve -8+20, the sulfur accounted for 19% of product and polymer coating - 3%. The nitrogen content was 16%.

Example 9. Granules of magnesium oxide-magnesium sulfate was coated with sulfur and then the polymer under the conditions of example 5. As magnesium oxide-magnesium sulfate used the product Martin Marietta "Crep Mag 36", 95% of the granules have a size of -6+16.

The product is coated, sifted through a sieve -6+16, was a product with variable ability to release substances and durable coating. A coating of sulfur accounted for 19% of product, and polymer coating - 3%. Magnesium content was 18%.

Example 10. It was prepared several batches of prototypes using different polymer coatings, applied on the basis of covered sulphur fertilizers. The preparation of these samples and the results obtained are described below.

For the first batch of samples in a drum coater described in example 5 was loaded with 750 g of granulated urea Cominco, 95% of the granules have a size of -5+8 system sieves U.S. sieve number 275. The drum was rotated at a speed of 20 rpm while heating the granules to a temperature of 80oC. the sulfur Melt (temperature 150 C) was filed by a gear pump. Flat jet was obtained by filing in the district is eaten with 2050 SS nozzle for liquid and 73328 SS nozzle for air. The flow of sulfur, sprayed air, at a speed of about 45 g/min was sent to the granules until the quantity of precipitated sulfur was 12% by weight of the final product (104,7 g).

Half the number of coated grey samples were taken on the test. The rest of immediately placed back in the drum and pre-heated to 60oC when the speed of rotation of the drum 20 rpm granules was applied to 17.4 g of a polymer melt (at a temperature of 125 to 150oC) that amounted to 2% by weight of the final product. As the polymer compositions used a mixture of 75% Chevron Gulftene C30+ alpha olefin wax and 25% of DuPont Elvax 420 (copolymer of ethylene and 18% vinyl acetate). The temperature during deposition was maintained at a level of 65 to 70oC for 3 minutes the Obtained product was cooled in the drum 60oC and in the fluidized bed 30oC. the Cooled product was sifted through a sieve -5+8.

Thus obtained samples covered with grey sulphate of potash, with a polymer coating and without it, were tested to determine their ability to control the release of substances before and after processing, simulating their discharge, by dropping from a height of 6.1 m (20 ft) in a steel Cup. Posablity are given in the table. Each value is the average of three measurements.

To get another batch of samples was applied 104,7 g of sulfur on 750 g of granulated urea, which amounted to 12%, using the same method and the same equipment as described above. Covered in grey granules was placed back in the drum, which is rotated with a speed of 20 rpm while heating the granules to a temperature of 60oC. the pellet was applied to 17.4 g of a polymer melt (at a temperature of 125 to 150oC) that amounted to 2% by weight of the final product. As the polymer compositions used a mixture of 20% of a copolymer of ethylene and ethyl acrylate (18% ethyl acrylate) manufactured by Union Carbide (DPDA 9169) and 80% alpha olefin wax Chevron C30+. The temperature during deposition was maintained at a level of 70-80oC for 3 minutes the Obtained product was cooled air in the drum 60oC and in the fluidized bed 30oC. the Cooled product was sifted through a sieve -5+8. The test results of the samples are given in the table.

To get the last batch of samples was applied 104,7 g of sulfur on 750 g of granulated urea, which amounted to 12%, using the same method and the same equipment as described above. Covered in grey granules pomes the ranula was applied to 17.4 g of a polymer melt (at a temperature of 125 to 150oC) that amounted to 2% by weight of the final product. As the polymer compositions used a mixture of 50% terpolymer ethylene, vinyl alcohol and vinyl acetate (manufactured by Allied-Signal Actol 70) and 50% alpha olefin wax Chevron C30+. The temperature during deposition was maintained at a level of 70-80oC for 3 minutes the Obtained product was cooled air in the drum 60oC and in the fluidized bed 30oC. the Cooled product was sifted through a sieve -5+8. The results of tests to determine the ability of the samples to a regulated release of substances are given in table.5.

Included in the table of results it should be noted that all of these products represented a fertilizer with efficient adjustable ability to release chemicals, except fertilizers coated only sulfur (100% release of substances in 7 days). Loss of the ability to control the release of substances in the discharge are presented in the form of increased DSM for 1 h ( 1 h). This value is the same for all samples tested. However, a value of 1 h for covered grey product without coating, probably would have been much higher if the value of DSR for the sample not subjected to the to visible as for other materials, the value of DSR which was about 10. Therefore, data presented in table show that is covered with a grey fertilizer with polymer coating has the ability to control the release of substances, and strength.

Although the description is given of preferred examples for implementing the invention, it should be understood that they are merely illustrative. It is obvious that the implementation of the invention is possible with the numerous changes in the composition of the compositions, conditions, operations and used materials without departure from the essence and scope of the invention as expressed in the following formula.

Literature.

1. US Patent 3342577.

2. Sulfur Inst. J. 4(3), pp.2-6, 1968.

3. Sulfur Inst. J. 8(4), pp.2-5, 1972.

4. Sulfur Inst. J. 8(4), pp.6-8, 1968.

5. Sulfur Coating of Urea Treated with Atapulgite Clay, Gilett G. L., Simmons, C. L., Lee, R. G., 198th American Chemical Society meeting in Miami Beach, Florida, September 1989.

6. Sulfur Inst. 3. 9(3/4), pp.8-12, 1973.

7. Sulfur Inst. 3. 12(1), pp.2-5, 1976.

8. Hort. Rev., I, pp.79-140, 1979.

9. US Patent 3252786.

10. US Patent 3372019.

11. US Patent 4881963.

12. US Patent 4042366.

13. US Patent 4676821.

14. US Patent 3576613.

15. US Rideline, representing a composition containing a core of particles of water-soluble fertilizer with a coating of sulfur layer, applied directly to the surface of the specified engine, characterized in that the said coating layer of sulfur caused approximately 0.75 to 10% based on the weight of the entire composition of the top coating, which is essentially stagnant at ambient temperature and is characterized by a melting point of about 60 - 105oC, with the specified external coating is a hard shell that is located outside of the coating layer of sulphur and which is stagnant at ambient temperature, resulting in the composition of the coated sulfur fertilizer is essentially dust-free handling, but such external coating comprises a mixture of about 5 to 50% based on the weight of the outer coating of the polymer and about 95 to 50% based on the weight of the outer coating of hydrocarbon wax, the said polymer selected from the group comprising copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylic acid, copolymers of ethylene and ethyl acrylate, copolymers of ethylene and vinyl alcohol, terpolymer ethylene, vinyl alcohol and vinyl acetate, and that is in store point of dropping about 60 - 80oC and containing less than 5% of the oil the U.S. standard D 721, in which essentially no aromatic and cyclic structures, and synthetic hydrocarbon wax having a melting point in the range of about 60 - 105oC and a molecular weight of between 400 and 600, as well as mixtures thereof.

2. Fertilizer under item 1, wherein the hydrocarbon wax is a mixture of synthetic olefins with an average molecular weight of more than 400 containing 0.5 - 2% saturated hydrocarbons, 30 - 40% of hydrocarbons with double vinylidene links 8 - 12% hydrocarbons with double inner ties and 50 - 55% of hydrocarbons with double alpha-linkages and having a dropping point of about 69 - 75oC.

3. Fertilizer under item 1, wherein the hydrocarbon wax is a paraffin wax containing less than 0.5% oil by U.S. standard D/21 and having a dropping point of about 60 - 70oC.

4. Fertilizer under item 1, characterized in that the polymer is a copolymer of ethylene and vinyl acetate containing 10 to 30% of vinyl acetate.

5. Fertilizer under item 1, characterized in that the polymer is a copolymer of ethylene with vinyl acetate, in which the mass ratio etilen - 20000.

6. Fertilizer under item 1, characterized in that the polymer is a copolymer of ethylene and acrylic acid, in which the mass ratio of ethylene units to the units of acrylic acid is about 50 - 10, and the molecular weight is in the range of about 2000 to 20000.

7. Fertilizer under item 1, characterized in that the core of the particles of water-soluble fertilizers include ammonium sulfate, ammonium phosphate, urea, superphosphate, dicalcium phosphate, basic calcium phosphate, potassium sulfate, potassium phosphate, potassium chloride, magnesium oxide, magnesium sulfate and mixtures thereof.

8. A method of obtaining a wear-resistant granular nokiausers essentially dustless disperse fertilizer with delayed allocation, comprising obtaining a quantity of fertilizer particles having a coating layer of sulfur, applied directly to the surface of these particles of urea, characterized in that the conducting adding metered stream containing composition for applying an external coating on the fertilizer particles in the form of a liquid melt, pellets or pieces with a diameter of less than 2 mm at a temperature of about 70 - 100oC, with the specified external coating is essentially n who will win the mixture for about 5 - 50% based on the weight of the outer coating of the polymer and about 95 to 50% based on the weight of the outer coating of hydrocarbon wax, the said polymer is chosen from the group comprising copolymers of ethylene and vinyl acetate, copolymers of ethylene and acrylic acid, copolymers of ethylene and ethyl acrylate, copolymers of ethylene and vinyl alcohol, terpolymer ethylene, vinyl alcohol and vinyl acetate, and mixtures thereof, and the hydrocarbon wax selected from the group comprising natural oil wax having a dropping point of about 60 - 80oC and containing less than 5% of the oil the U.S. standard D 721, in which essentially no aromatic and cyclic structures, and synthetic hydrocarbon wax having a melting point in the range of about 60 - 105oC and a molecular weight of between 400 and 600, as well as their mixture, mixing the mixture of compositions for coating and coated sulfur particles fertilizer with the implementation of mixing the above-mentioned mixture and cooling the mixture to ambient temperature when mixed with receiving fertilizer, having a hard outer coating on the coating layer of sulfur and non-sticky at ambient temperature, while fertilizer on sumdorong paraffin, a mixture of synthetic olefins with an average molecular weight of more than 400, containing 0.5 - 2% saturated hydrocarbons, 30 - 40% of hydrocarbons with double vinylidene links 8 - 12% hydrocarbons with double inner ties and 50 - 55% of hydrocarbons with double alpha-linkages and having a dropping point of about 69 - 75oC.

10. The method according to p. 8, characterized in that the hydrocarbon wax used paraffin wax containing less than 0.5% oil by U.S. standard D /21 and having a dropping point of about 60 - 70oC.

11. The method according to p. 8, characterized in that the polymer used is a copolymer of ethylene and vinyl acetate containing 10 to 30% of vinyl acetate.

12. The method according to p. 8, characterized in that the polymer used is a copolymer of ethylene with vinyl acetate, in which the mass ratio of ethylene units to vinyl acetate is about 20 - 2, and the molecular weight is in the range of about 2000 to 20000.

13. The method according to p. 8, characterized in that the polymer used is a copolymer of ethylene and acrylic acid, in which the mass ratio of ethylene units to the units of acrylic acid is about 50 - 10, and the molecular weight is in the range of about 2000 to 20000.

14. The method according to p. 8, characterized in,inu, superphosphate, dicalcium phosphate, basic calcium phosphate, potassium sulfate, potassium phosphate, potassium chloride, magnesium oxide, magnesium sulfate and mixtures thereof.

 

Same patents:

The invention relates to a method for producing granulated urea, which solves the problem of removing moisture in the method column of the granulation and the problem of concentration of dilute formaldehyde by granulation method using a fluidized bed or a fluidized bed spouted bed when urea granularit in the presence of formaldehyde, i.e
The invention relates to techniques for the production of granulated potassium fertilizers by granulation by extrusion of a mixture of potassium chloride with urea and other mineral components
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The invention relates to the production of mineral fertilizers and can be used to produce liquid nitrogen fertilizers for production of liquid nitrogen fertilizers based on urea and ammonium nitrate, known as CAS

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FIELD: chemical industry, agriculture, in particular hardness removal agent and saltlick for cattle.

SUBSTANCE: salt with pH 4-10 is pressed under 5000-2500 N/cm2. Salt contains NaCl, less than 0.1 wt.% of water, and iron-ammonium complex of polyhydroxycarboxylic acid in amount sufficient to obtain non-caking salt. As iron-ammonium complex of polyhydroxycarboxylic acid iron-ammonium citrate with molar ratio of iron to citrate-ion from 0.5 to 2 and molar ratio of ammonium to citrate-ion from 0.5 to 2 may be used. Finished product contains 0.1-20 mg/kg of iron and has form of briquettes, balls, bars, crushed plates, tablets, etc. Invention makes it possible to provide good formability under high pressure and conserve pressed product shape in moist medium for a long time.

EFFECT: products from salt non-caking at storage and conveyance.

11 cl, 6 tbl, 2 dwg, 7 ex

FIELD: mineral fertilizers.

SUBSTANCE: invention relates to granulated mineral fertilizers containing ammonium phosphates modified by surfactants and powdering substances, which do not lose their physicochemical properties during transportation and storage. Manufacture process comprises granulation of ammonium phosphate pulp, drying of granules, sorting and selection of commercial fraction, cooling and addition of modifying supplements. The latter are added in the cooling stage into zone with bed temperature by 5-10°C exceeding temperature of cooled product. Conditioning additives utilized can be either only liquid or the same mixed with dry powdering substances.

EFFECT: improved quality of surface coverage and simplified process.

2 cl, 3 ex

FIELD: chemical industry; production of fertilizers.

SUBSTANCE: the invention is pertaining to the field of chemical industry, to production of fertilizers, namely to the methods of production of granular fertilizers, and in particular, to nitrogenous and complex fertilizers, and may be used at production of the granular fertilizers with the improved properties. The method of treatment of granular fertilizers provides for application on the surfaces of the fertilizer granules (for example, carbamide, ammonium nitrate, ammonium chloride, complex NPK fertilizers), having temperature from 45 up to 100°C of the mixture of the surface-active substances with the film-forming substance in the aqueous medium. For the application may be used both ionogenic and non-ionogenic surface-active substances. The film forming substance may be chosen from the group, which contains amino-formaldehyde resins and epoxide resins, polyvinylacetate and animal glues. The technical result of the application of the additives at the heightened temperature results in the fertilizers granules strength improvement.

EFFECT: the invention ensures the fertilizers granules strength improvement.

3 cl, 36 ex, 4 tbl

FIELD: anti-conglomeration agents.

SUBSTANCE: invention relates to loose product based on potassium formate, which contains 0.1 to 1% water and 0.5-5% water-soluble conglomeration-preventing agent, such as potassium carbonate or potassium hydroxide, which possesses affinity for water and corresponds to equilibrium humidity below equilibrium 15% relative humidity (22°C) for potassium formate.

EFFECT: provided modifying and conglomeration preventing agents for potassium formate to allow it to achieve looseness under practical storage and processing conditions.

3 cl, 4 tbl, 4 ex

FIELD: agriculture.

SUBSTANCE: invention relates to agriculture composition comprising nitrogen-containing fertilizer as substrate and 0.05-1.5 mass % coating applied thereon to decrease dust forming and fertilizer conglomeration. Said coating includes conditioning agent containing wax, oil, resin, surfactant and optionally biodegradable polymer. Conditioning agent useful in fertilizer applying includes (mass %) wax 5-50; oil including vegetable oils, liquid animal fats, marine animal fats or products thereof 5-75; resin 30-60, wherein said resin represents natural resin or residue from distillation of unsaturated liquid animal fat, fish oil, or vegetable oil; surfactant 2-15; and biodegradable polymer 0-5 %. Conditioning agent is easily applied on fertilizer particles and provides flowability and simplifies transportation.

EFFECT: composition having non-toxic and environmentally friendly coating.

10 cl, 4 ex, 1 tbl, 4 dwg

FIELD: mineral fertilizers.

SUBSTANCE: composition preventing caking of mineral fertilizer during storage and transportation from manufacturer to consumers is based on mineral oil and further contains, wt %: imidazoline 9-13, ethylene/propylene copolymer 0.4-1.5, paraffin 14-30, oil-soluble calcium sulfonate 0.5-2.5, and polymethylsiloxane 0.003-0.005.

EFFECT: reduced caking ability and granule conglutination of fertilizer.

2 cl, 2 tbl

FIELD: mineral fertilizers.

SUBSTANCE: invention relates to a method for conditioning mineral fertilizers. Composition for conditioning mineral fertilizers comprises active component based on primary aliphatic amines, hydrocarbon solvent, modifying agent for fluidity loss representing solid hydrocarbons with melting point 50oC, not less. As active component the composition comprises product of partial or complete neutralization of primary aliphatic C10-C20)-amines with (C2-C30)-carboxylic acids wherein part of neutralized amine is varied, and hydrocarbon solvent represents purified distillate or residual mineral oils, or a mixture of distillate and residual mineral oils containing the main fraction 85%, not less, with the boiling point above 350oC in the their following content in the composition, wt.-%: active component, 10-25; hydrocarbon solvent, 40-80; temperature modifying agent for fluidity loss, 1-20. The composition of temperature 70-100oC, viscosity value at this temperature 5-50 mPa*c, temperature fluidity loss 20-60oC is applied on surface of granules in the amount 0.02-0.2% of fertilizer mass to be treated. Components of the composition provides preparing inexpensive and effective conditioning composition that doesn't form aerosol in its applying on fertilizer and not aggressive to material of transporting bands used in transport of treated product.

EFFECT: improved preparing method, improved and valuable properties of composition.

6 cl, 5 tbl, 4 ex

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