CS213450B1 - Method of preparation of np a/or npk of the suspension fertilizer containing the slow liberating nitrogen - Google Patents

Abstract

Process for preparing NP and / or NPK suspension fertilizer containing slow ee release nitrogen from aqueous solutions and / or suspension, containing urea and acid fosforční! in molar ratio = 0.8 eq 1.5 which 88 did not react with aqueous with a solution of fermeldehyde, with a pH of the reaction adjusting the ee to 5.5 to 9.5, and preferably n with 6.5 to 8.0 ammonia, ammonia water and / or dressing hydroxide and to the suspension! hydrophilic aluminesilicate is added in the form of a powder and / or an aqueous dispersion, containing it will fall additive, and the stomach is biologically active substances.

Description

The present invention relates to a process for the preparation of NP and / or NPK of a slurry-containing slurry containing vapor-releasing nitrogen from aqueous solutions and / or slurry. containing phosphoric acid and urea.

Nitrogenous fertilizers containing nitrate and / or ammoniacal and / or acidic nitrogen are subject to changes which result in significant attributes of this essential macro-nutrient. In particular, these losses were attributed to the relatively rapid nitrification of the ammonia nitrogen, the nitrification and leaching of its nitrate form, as well as the enzymatic decomposition of the amide form of nitrogen.

In an effort to efficiently utilize nitrogen-applied fertilizers by industrial fertilizers to eliminate the negative environmental impact and to minimize the split application of nitrogen, long-term industrial nitrogen fertilizers containing urea-containing condensation products have been developed and have been proven in agricultural practice. aldehydes (known under the commercial names: Ureaferm in the USA; Crotodur and Floramide in the Federal Republic of Germany; Z-urea in Japan and others), of which nitrogen is scarcely leached and practically not nitrified.

Fertilizers containing urea-releasing nitrogen-based or non-amide-nitrogen-containing compounds capable of condensing with aldehydes are prepared under the catalytic action of acids or bases / US Pat. 3,759,687; DOS 2 157 532 (1973), DOS 2 422 238 (1975) and are applied in the form of solid or suspension fertilizers often also containing pesticides, trace elements, nitrification inhibitors, restorers (US Pat. No. 4,047,922 (1976), Jap. pat.

063 378; US Pat. No. 4,025,325 (1977), wherein by adjusting the molar ratio between urea and aldehyde, it is possible to prepare properly modified products with controllable water-soluble (US Pat. no. 4,033,745 (1977); Aut. osvod. USSR no. 549,453 (1977); patents and aut. certificate. no. 125,701 (1968); 135,890 (1970); 141057 (1971); 149,261 (1973); 171,721 (1978); 178, 542 (1979).

Urea and formaldehyde suspension fertilizers prepared from catalytic H 2 PO 4 are stabilized by attapulgite / US Pat. No. 4,145,207 (1977) or by dust dust / Aut. certificate. USSR 590 318/1978 //.

It has now been found that stably suspended multicomponent fertilizer of comparable and superior properties to those described above may be prepared from aqueous solutions and / or suspensions containing phosphoric acid and urea. The essence of the invention is that aqueous solutions and / or suspensions containing phosphoric acid and / or dihydrophosphoric acids and urea in a CO / NHg / g: H ^PO ^ molar ratio of 0.8 to 1.5 are reacted with an aqueous solution. the formaldehyde and the pH of the reaction mixture are desirably adjusted to a value of 5.5 to 9.5, preferably 6.5 to 8.0 with ammonia and / or ammonia water and / or potassium hydrexide, and / or potash, the hydrophilic elumino-silicate is desirably added to the mixture. in the form of a powder and / or an aqueous dispersion, optionally containing a stabilizer and / or flowing agent, and optionally also one of the biologically active substances.

In addition, it has been found that in order to obtain the urea-thermeldehyde condensate of suitable physical properties, the βίβ technological process is preferred so that the total water content of the system is higher or even equal. 30 wt.%.

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Advantages of a method for preparing a stabile suspension NP e / or NPK fertilizer according to the invention which comprises nitrogen in the ratio e and release form containing phosphorus in a water-soluble form; The following are the following:

- allows for technologically and energy-saving methods / reaction is slightly exothermic and takes place autothermally / efficiently utilized mother liquors from urea phosphate crystallization (mother liquors contain on average 40 to 60% urea phosphate), prepared from both rermic and extractive phosphoric acid preparation NP and / or

NPK of suspension fertilizer using the method of the invention.

In view of this advantage, in the production of urea phosphate from thermic phosphoric acid, the energy costs necessary to concentrate and / or dry the mother liquors are saved, and the production of urea phosphate from extractive phosphoric acid resolves in this way the residual spraying of substantially insoluble and dissolved contaminants which could otherwise only be returned to the manufacturing process to a very limited extent.

A further advantage of the process according to the invention is the affordability of formeldehyde and the possibility of using the formeldehyde solutions corresponding to many chemical plants. Stepping elements, or plant protection agents, may be added to the suspension fertilizers prepared according to the invention, as necessary, thereby ensuring that all the nutrients and substances necessary for their harmonious development are supplied to the restines.

The following examples illustrate but do not limit the scope of the invention.

Example 1

200 parts by weight of urea phosphate prepared from thermal phosphoric acid and crystalline urea and 292 parts by weight of water were introduced into a three-necked flask equipped with a powerful stirrer and thermometer.

The composition of the urea phosphate used was as follows:

43.83% PgO 4 total, 17.24% amide nitrogen, 0.8% water. With vigorous stirring, 103.1 parts of 36.84% aqueous formaldehyde solution were charged over 5 minutes and the mixture was stirred for 2 hours. The liberated H-PO 4 was neutralized with ammonia so that the pH of the suspension was 6.95. To 200g of the suspension was added 2.0 parts by weight of attapulgite dispersion prepared from attapulgite of American origin and monitored the course of sedimentation over time.

Preparation of dispersion for suspension stabilization:

55.1 parts by weight of water

19.3 parts by weight of urea to be added 0.59 parts by weight of Na2PO4. HgO

25.0 parts by weight of attapulgite.

Physicochemical constants of suspension slurry:

specific weight: 1 297,4 kg.m ”^ dynamic viscosity: 309 mPa.s stability after 7 days storage: 98% v / v resuspendability: very good

Suspension fertilizer composition: 7,7% N total and 15,2% P ₂ O ₅

Example 2

An analogous eye procedure in Example 1

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To 333.3 parts by weight of the crystallization liquor from the crystallization of urea phosphate prepared on the basis of thermal H 3 PO 4 and crystalline urea in an equimolar ratio containing 40% H ₂ O, 103.1 parts by weight of technical 36.84% formaldehyde were fed. The released H3PO4 ^es neutralized with gaseous ammonia to pH 6.95 if získenej suspension was added 29.1 parts by mass 15% aqueous bentonite dispersion containing 1% by dry mass sulfite liquor.

Properties of prepared suspension fertilizer:

specific gravity: 1 312.3 kg.m. ^ dynamic viscosity: 857 mPa.s stability after 7 days of monitoring: 97.5% v / v 2.5% v / v of total suspension / resuspendability: good composition: 10 3% total nitrogen, of which 7.42% amide N; 18.8% total, P ₂ O 4;

Example 3

400 parts by weight of crystalline urea phosphate prepared by reacting crystalline urea with phosphoric acid and 266.6 parts by weight of water were charged to a three-necked flask equipped with a stirrer and a thermometer.

The urea phosphate composition was as follows:

42.83%? ^Ce l 2θ5 ^metal EHO

17.24% amide nitrogen 0.06% Fe; 0.096 Al; 0.110% Mg.

During the mixing stage, 206.2 parts by weight of technical 36.84% formaldehyde were molten to the solution. The suspension obtained was neutralized by addition of 870.85 parts by weight of a 40% aqueous KOH solution at pH 7.8, and after adding 13.34 parts by weight of an aqueous 15% bentonite dispersion containing 1% dry matter of the sulphite liquor, the properties of the prepared suspension fertilizer were monitored. .

•with

Suspension density: 1270.5 kg.m- ^J

Viscosity / dynamic: 311 mPa.s

Stability after 7 days of monitoring: 96% v / v of a layer corresponding to 4% v / v of the total. volume of suspension.

Resuspendability: very good

Suspension fertilizer composition: 3.4% nitrogen in emidic form; 8.9% P ₂ O ₅ ; 14.8% K ₂ 0

Claims (3)

OBJECT OF THE INVENTION Process for preparing NP and / or NPK of a slow-release nitrogen fertilizer, characterized in that aqueous solutions and / or suspensions containing urea and phosphoric acid in a polar ratio of 0.8 to 1.5 are reacted with an aqueous formaldehyde solution, wherein the pH of the reaction mixture is adjusted to 5.5 to 9.5 and preferably at _p H 6.5 to 8.0 with ammonia, ammonia water and / or potassium hydroxide if the suspension ee úalej treated hydrophilic aluminum silicate in the form of powder and / or the aqueous dispersion , optionally containing a flowable additive; and biologically active substances.