CS253425B1 - Solid nitrogen industrial fertilizer with the contents of phosphorus and sulphur and process for preparing therrof - Google Patents

Description

The invention relates to a solid nitrogenous fertilizer containing phosphorus and to a process for its preparation.

One of the particularly important problems of current chemistry and agrochemistry of mineral plant nutrients is the effort to increase the utilization of applied nitrogen.

The nitrogen applied in the fertilizer is reduced to 35% to 60% only. The assessment of the losses of nitrogen from the flood environment is approached from at least three points of view: economic, hygienic-toxicological and ecological-hilarious. Nitrogen losses. from the soil, they basically spawn in three basic ways:

- denitrification and volatilization of ammonia, - leaching, - erosion.

Most of the nitrogen from the soil is lost by leaking its gaseous forms into the atmosphere. It is reported that this process accounts for 92 - 98% of total soil nitrogen losses. The remainder are leaching-related losses, respectively. by erosion (BIELEK P .: Nitrogen in Soil and Its Metamorphoses, Nature 1984, Bratislava). The losses of applied nitrogen are also largely due to the rapid hydrolytic cleavage of the amidic nitrogen by the enzyme urease to ammonia, carbon dioxide and water, and the subsequent bacterial oxidation of the ammonia nitrogen to nitrites and nitrates.

It is known that urea incorporated into the soil decomposes very rapidly - depending on the environmental conditions within 5-10 days, the amide nitrogen is in the form of ammonia]. By the action of nitrifying and nitrating bacteria, the ammonia nitrogen is gradually oxidized to nitrites (nitritation) and subsequently to nitrates (nitratation). The nitrates do not bind to the sorbent complex in the ground, they are well soluble in water and consequently very mobile in the soil. If inferior amounts of nitrates than the plants are capable of being absorbed through the root system, they have a multilateral negative effect:

- agrochemical value and nitrogen utilization efficiency decreases, - soil properties deteriorate (accumulation of acid products, soil humus decreases), - the environment is negatively affected (contamination of drinking water sources, eutrophication, accumulation of nitrates in biomass of some plants, etc.).

Especially in recent times, the attention of researchers around the world has been focused on the study of substances whose application would increase the efficiency and utilization of amide or nitrogen in fertilizers. In addition to several simpler compounds of the type of inorganic salts - CuSOd. . 5H2O, sodium tetraborate, NaF {GEISSLER, P. R. and spoh: US Pat. No. 3,523,018], especially in recent years, the focus of research is increasingly focused on verifying the inhibitory activity of even more complex compounds of inorganic and mainly organic nature. PETERSON, A.F. and WALTER, C.R. have patented the use of pyridine-3-sulfonic acid for this purpose (U.S. Pat. No. 3,547,614). SOR, K. in U.S. Pat. no. No. 3,388,989 recommended the use of a wide variety of compounds (formaldehyde, boron and fluorine compounds with a heavy metal cation having an atomic mass greater than 50, etc.) and in U.S. Pat. no.

No. 565,599 discloses the use of several boron compounds. JASCHE, K. and colleagues have patented the use of monophenyldiamine phosphoric acid to inhibit hydrolytic decomposition of urea (NDR Patent No. 128,315). BALESS, A.V. and MILLNER, D.E. have US Pat. no. No. 4,242,325 protected use of phosphoric triamide. The use of several phosphoric acid amides, aminobenzeneboric acid and aminophenols has protected the patent in the past period. ALLIED Corp. (U.S. Pat. No. 4,462,819,

517,002, 4,517,003, 4,517,004, 4,517,005, 4,517,007, 4,518,413, 4,528,020; Europa patents no. 119,487,119,494,119,495). Inhibition of urease using sodium, copper, manganese and zinc salts of dithiocarbamic acid is the subject of the GDR pat. no. 157 611. An inhibitor based on phosphoric acid diamide phenyl ester complexes contains NDR pat. 215 075. Another GDR patent (No. 3,319,345) describes a long-acting nitrogen fertilizer consisting of a urea-formaldehyde dispersion, dicyandiamide and a polymer of vinyl alcohol or a carboxylic acid aldehyde. German Patent No. 3 322 724 protects urea-based fertilizers containing biomo-nitroalkane derivatives as stabilizing additives.

It has now been found that increasing the efficiency and utilization of nitrogen in urea, while maintaining the good physical-handling properties of industrial fertilizers while ensuring the presence of two other important biogenic elements - phosphorus and sulfur, can effectively be achieved by preparing and using phosphorus-containing solid nitrogen fertilizers. sulfur within the meaning of the present invention.

The principle of the invention is that the solid nitrogen fertilizer containing nitrogen bound in amide form, phosphorus and sulfur contains 82.0 to 99.95 wt. % urea-CO (NH 2) 2 and 0.05 to 18.0 wt. % of a phosphorous compound characterized by formula (I)

ri

S = P-NH 2

R2 (I) in which the radicals R1 and R2 may be an amino group (—NH2) and / or a phenoxy group (—OH5C6).

Investigations have shown that the nitrogen-containing solid nitrogen fertilizer bound in amide form, phosphorus and sulfur according to the invention can be produced in a manner based on homogenization of 82.0 to 99.95 wt. % urea with 0.05 to 18.0 wt. Of a phosphorus-sulfur compound of the formula I at a temperature of 110 to 145 ° C, the mixed melt thus prepared is sprayed onto the cooling medium, thereby solidifying the mixed melt droplets to form granular solid nitrogen fertilizers containing amide nitrogen, phosphorus and sulfur.

A phase equilibrium study of the binary systems: CO (NH2) 2 - PS (NH2) 3 and CO (NH2) 2 - SPfOHsCe) (NH2) 2 revealed that the addition of these thiophosphoric amides to the urea in the range 0.05 to 18, 0% causes a decrease in the melting point of the studied binary mixture.

The nitrogen-phosphorus-sulfur fertilizers according to the invention are more agrochemically effective than the urea currently used for fertilization alone.

The following examples illustrate but do not limit the invention in any way.

Example 1

In order to prepare the samples of solid nitrogen fertilizers containing amide nitrogen and phosphorus according to the invention, to determine their melting points and to assess their compatibility, a glass beaker tempered in silicone oil at 140-145 ° C was used under laboratory conditions. The beaker was weighed with the necessary amount of crystalline urea - CQ (NH2) 2 and thiophosphoric triamide - PS (NH2) 3, prepared by α-moniacalization of PSCI3 at -15 ° C, following the procedure of KLEMENTA, R. (Inorganic Syntheses, Vol. VI, McGraw - Hill Book Gomp., Inc. New York 1960, p. 111).

The mixture was melted while stirring, and the homogeneous melt was then poured onto a Teflon thatch, where it was allowed to cool freely. The solidified melt was crushed in a porcelain mortar and a 1.25-2.5 mm particle size fraction was sieved through sieves.

For individual samples of blended melts, they were determined by means of a " spotting " and also by means of a Kofler block their melting points. The properties of prepared samples of mixed melts are summarized in the table below:

Ingredient weights (g)

Content of pure plant nutrients in prepared blend

Melting Point Mixed Melting Point

CO (NH 2) 2 PS (NH 2) 3 % N amide melt% P2O5 % WITH n ° (° C) 118.75 6.25 46.16 . 3.19 ^; 1.44. 133.1. 112.5 12.5 45.72 6.39 2.89 131.7 106.25 18.75 ' 45,28 9.58; ,. · 4.33 130.4 _; · Example 2 From the results laboratory model

Under model laboratory conditions, the ammonization of urea and mixed melt prepared as described in Example 1 from urea, phosphoric acid monophenyldiamide / PS (OC <3Hs) (NH 2 / a) and thiophosphoric triamide (PS [NH 2) 3) by enzymatic hydrolytic cleavage by microorganism called. urobaktérií.

The mixed melt contained 95 wt. % urea and 5 wt. % of the thiophosphoric acid amides specified above.

The black-black surface layer was allowed to freely air dry for model tests, then crumbled and sieved through a 2 mm sieve.

To the 240 cm ³ Stohman flasks were weighed 10 g of pod and 10 mg of amidic nitrogen from each of the urea and urea samples was added by pipette. from its mixed melts in 5 cm ^{3 of} aqueous solution each time. After mixing the contents of the flasks, they were incubated at 30 ° C for 24 hours.

After incubation, the samples were extracted with 50 centimeters of a ³ L N solution of K 2 SO 4 containing 20 ppm phenylmercuriacetate (C 6 H 5 -Hg-O-CO-CH 3) and the extract analyzed for ammoniacal nitrogen content. All variants of the model experiments were repeated 5 times. The following table summarizes the averaged results of the ammoniacal nitrogen content in the µg / g pod incubated with 1 mg of amide nitrogen.

Amide nitrogen source used for incubation, µg N _N H 4 + / 1 g pod / (30 ° C / 24 hours) (average value)

1. Urea / CO (NH2) 2/284

2. mixed melt 14 / CO (NH2) 2 + 5% PSfOCsH5 (NH2) 2 / experiments showed that when mixed melt was applied, the efficacy of the soil amide nitrogen hydrolysis was suppressed as a result of which better nitrogen utilization in products of this type could be expected.

Example 3

23.25 t of crystalline urea and 1.75 t of thiophosphoric triamide PS (NH 2) 3 are continuously fed to the hopper of the slug feeders from three centrifuges on an average hourly basis. The dosing components are pneumatically conveyed to a cyclone separator located above the melter to which the mixture is dosed uniformly through the turnstile shutter of the cyclone separator. The mixture is melted in a steam-heated melter at a temperature close to 132 ° C. The homogeneous melt is pushed through a buffer reservoir by means of a pump into a spray perforated scythe which is located at the top of the granulation tower. Cooling air is sucked into the granulation tower through the openings uniformly distributed around its circumference at the bottom. The diameter of the granulation tower is about 13 m and its effective height is about 45 m.

The blended melt is sprayed into a droplet form by means of a perforated nail, which is gradually cooled by dropping against the cooling air stream and gradually solidifies into the form of spherical particles of medium size of 2.5 to 3 mm. The solidified mixed melt granules are gathered from the conical bottom of the granulation tower by a slowly rotating two-arm scraper with vanes. In this way, an average of 25 t of a phosphorus-containing, solid, granular nitrogen fertilizer according to the invention was prepared per hour, on average, containing 45.6% amidic nitrogen, 4.5% P2O2 and 2.0% sulfur.

3. mixed melt / CO (NH2) 2 + 5% PS (NH2) 3 /

Claims (2)

1. Solid nitrogen fertilizer containing nitrogen steeped in anrthdic form, phosphorus and sulfur; marked by ^ ce in that it comprises from 82.0 to 99.95 percent by weight of urea - CO ^(NTE) 2, and 0.05 to 18.0 wt. % of the phosphorus-sulfur compound characterized by the formula (II) S = F— Nřfz, I! K2 LU in which the radicals R 1 and R 2 are the amino group of Alzez to (—NH2) and / or the phenoxy group (—OH5eej). 2. A process for the production of a nitrogen-containing solid nitrogen fertilizer impregnated in amide form, phosphorus and sulfur according to claim 1, characterized in that the mixture comprises 82.0 to 99.95% by weight. % urea and 0.05 to 18.0 wt. percent of the phosphorus-sulfur compound of formula I is. homogenizes at a temperature of 110 to 145 ° C; the mixed melt thus prepared is sprayed into the cooling medium of the mixed melt in the form of granules of a solid nitrogen fertilizer containing phosphorus and sulfur.