CS237462B1 - Process for preparation of condensed ammonium phosphate - Google Patents

Description

The present invention relates to a process for the preparation of condensed ammonium phosphates which allows easy preparation without the need to include commercially available trihydrogenphosphoric acids.

A melt of condensed phosphates and amine in yc ^ ^ h h, consisting of a mixture of dicalcium phosphate dihydrogen and condensed ammonium phosphates characterized by the following aum pattern:

^fH 4m ^H (n + 2W ^P n ° 3n + P where n 2 am li n + 2) is the basic starting material - an intermediate product of the production of so-called solution or suspension liquid multi-bed fertilizers.

Although ammonium (KFA) condensed melt condensed for the first time on an industrial scale for the first time in connection with the preparation of liquid fertilizer 11-33-0 was prepared in 1957 in Wst Kjj Liquid Fertility! Cc ^ pans in Η ^ Μ ^ Η · (USA), the predominant ventricular uterus. basic nitrogen-phosphorous liquid fertilizers of the polyphosphate type still use in their preparation in 1 already classical processes, which is based on the naturalization of polyphosphoric so-called. ammonia water or ammonia gas. The process for producing KFA by neutralizing polyphosphoric acid with ammonia - can be simplified as follows:

Stage 1 - preparation of pslyfsysic acid (so-called superzoisic) dehydratacis acid H ^ PO ^ “W ---- * -----> ^Hn +2 ^P n ° ³ⁿ ₊ 1 V '

2nd stage - n ^ i ^ t ^ t ^ i ^^ Lize pslyOssOore acid

H _{n +} 2 ^F n ° 3n + 1 ⁺ H ( _n +2) - ^ m ^P n ° 3n + 1 or ^H n + 2 ^P n ° 3n> 1 ⁺ "(NH ₃ .H ₂ O) · ^ --- -><NH ₄ ) _B H _{(n + 2)} _ _B P _n O _{3n +} ,> Η, Ο

However, these processes are already overcome because of their lack of energy efficiency in operational practice. The concentration H ^ PO ^ and the superfosOsrečnú acid is first to be added to the system Vel'Ké rniožstvo energy and on the other hand, no ^p r ⁱ ^ Cu ^ WAR. the ammonia thus prepared liberates 1.0. (2,5.1 ^o5 kcal) per ton of hot melt, ^and n ^y KFA. .

The released neutralizing heat cannot be sufficiently utilized in the process and needs to be removed from the system by cooling (approx. 3/4) (Egan, EP - Wakeffeld, ZT: J. Agr. Food Chem., 13, 1965, No. 1, pp. 99-100). , Kelso, TM - Stumpe, JJ - Willismson, PC: Com. Fert. 11, 1968, No. 3, pp. 10-12, 14-16). In addition to the aforementioned disadvantage, the successful mastering of technology through super-phosphoric acid places particularly high demands on the corrosion resistance of metallic constructional oakers (Medne, RS-Lee, R. G.C.): Use of Pipe Reactor in Product Product of Liquid Feerilizers with Vera High Polyphosphate Content

Feetilizer Solutisns, 15, 1972, No ' 2, p. 32 to 45; Achorn, F.P.-Balay, H.L.-Kimbmugh, H.L .: Uses of the Pipe Reactor Procession for the Production of High Pnlnphosphate

Liquids. Fertilizer Solutions, March-April 1973, p. 44 to 54; Achorn, F. · P. - Kimbrough, H. L: Latest Developmeets in Coimera Use of the Pipe Reeator Procese. Fertilizer Solutions, July-August, 1974; Barber, J. C .: Stage and Contairment of Phosphoric Acid and Liquid Feetilizer. Feetilizer Solutions, September-Octomber 1975; Achorn, F. P. - Whhght, E. B. - Baaiay, H.L .: Corrosion Problems Hanes Be Alleviated with Right Maaeerals. Feerilizer Solutions, Jay - June 1976).

The túčaanosti about 70 sites in the United States and 4 plants in Franhúzsku produce liquid fertilizer 10-34-0 type of superfosforečnej typically prepared by concentration of the purified ^{н з Р} ° 4 The means by wet laid so. extraction H 2 PO 4.

The development of processes for the production of nitrogen-phosphorous liquid fertilizers based on KFA is therefore increasingly oriented towards the most efficient use of the heat released during the neutralization reaction of phosphoric acid with ammonia to dehydrate the reaction mixture. Processes of this type have two mainly prednossi; The released heat of neutralization is discharged directly in the production process and the substances present in the technology are characterized by a lower corrosion aggressiveness towards the metallic material. Simultaneously, the neutralization and the molecular dehyddation of the reaction may be described by the reaction scheme:

n Η · ^ ⁴ + m KHj ---------- * ' ^МН 4> 1 ^Н (п + 2 ^ 11 ^Р о ⁰ ЗоН + <n *,) H ₂ 0

Primarily, KFA melt production is protected by multiple patents (U.S. Pat. No. 3,375,063,

(+420) 382 059, 3 399 032, 3 420 624, 3 429 624, 3 464 808, 3 503 706, 3 -849 175, 3 650 727,

677 734, 3 723 086, 3 733 191, 3 788 817, 3 949 058; 1,909,413, Franc.

U.S. Pat. 1,386,897, 1,426,746, 1,493,803, South Africa. U.S. Patent 67/5806 et al. certificate

[0006] USSR 220 965), which differ from each other in particular the type of acid used, its concentration and purity, the type of reactor used, the method of conducting the reaction, the method of capturing excess ammonia from the technological stage of KFA melt preparation. components, working pressures, reaction mixture defoaming agents, and the like.

From the production processes using commercial extractive phosphoric acid, the method known as POLY-ACTOR PHASE developed by the American company FERGUSON INDUSTRRES, Imc. Swift Aphichttural Chemmcals has begun manufacturing polyphosphate-type nitrogen-phosphorous-liquid fertilizers from commercial extractive H 2 PO 4 after a long-term semi-operational research.

The company acquired this experience in the construction of a new 10-34-0 production unit in Mont Pulaski, USA. Teclmológia fy. Swift is characterized by a patent-protected tube T-reactor (U.S. Patent Nos. 3,464,808, 3,550,706, 3,649,175, 3,650,727 and 3,677,734). A two-stage process for producing liquid fertilizer Ю-34-0 prepared by reacting H 2 PO 2 with ammonia gas, developed by NFDC-TVA (U.S. Pat. Nos. 3,382,059, 3,399,032, 3,420,624, 3,429,624, 3 464 808, 3 503 706, 3 649 175, 3 650 727, 3 677 734, 3 723 086 and 3 733 191), also verified by the French company Kaatrnlach-GairnOer (Kaltanbach et Gaairn0er, Paris: Chem. Ing.) Techrn, 42, 1970, No. 24, pp. 2,309, Kooiarevski, I., ProructCsn the Aimionium Polyhospheres and the Liquid FeetilCzeis from 52-54%.

Phospho-O-Acid. In: Proceedings of the 11th International Symposium on Industrial Fertilizers. Unido. Vienna 1971; toltenbach and Cie: 192, Grande Rue, 92 310 North (France), Kaltenbach Processes - Liguid FeetilCzris ^ η ^ ηο ^^ from Polyphosphates (B.r./ 2s.). In technology, this technology uses a liquid fertilizer plant in Moo0-Nótra-Dáoer to buyers of 1! Ο € ^^ for the direct preparation of liquid NP-fertilizer using a technology labeled PSG offered by the French company Pechiney-Saint-Golain.

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237462 4

By generalization of the published knowledge it can be stated that the greatest difficulties in directing the method of production of KFA from the extraction H? PG? Arise:

- reaction foaming (due to the presence of organic substances),

- corrosion of production equipment (reactor),

- · formation of incrusts on the walls of the reactor (incrustation is conditioned by the content of contaminants of inorganic 1 organic character in the treated acid, mainly of the so-called Black type),

- achieving the necessary degree of conversion of monophosphonates (MF) into condensed phosphates (KF),

- Insufficient use of ammonia and the like (Fleming, JD: 'Polyphosphates Are RevvSutisnizing Fertilizers-Part I-Wiat Polyphosphates Are. Farm Chemicaas, 132, 1969, n. 8; Siegel, MR ~ Young, RD: Polyphosphates Are Rewoutionizing Feetilizers-Part II - Base Maateials, Farm Chemicaas, 132, 1969, p. 9, p. 41, Achorn, FP - Scoot, WC: Polyphosphates Are RevvSutiSiizi Feetilizers - Part III - Polyphosphates II Miitures, Farm Cheelicaas, 132, 1969, p. Huffman, E. 0. - Newnmn, EL: Polyphosphates Are RevvSutisliizCig FertilCzets - Part IV - Behavior and Glucose Farm Chemicaaз, 133, 19 * 70, δ.2; MeHne, RS-Lee, RG - Scoot , WC: Use from Pipe Reactor II the ProductCsi of Liquid FertilCzets with Věry or Polyphosphate Comient, FertilCzet Sc ^^ ons, 16, 19 * 72, pp. 32, 45; Achorn, FP - Balay HL - KlmbroUjgh, H. L: Coomercial Uses · The Pipe Reactor Process for the ProductCsi of High Polyphosphate Li-quids.

FertilCzet SoSisis, Mati-Apptl 1973, p. 44 to 54; Achorn, FP - K ^ тцв !!, H. L: Lateet Developments C ^ (ϋΓ Ι Ι of of of of of of of of ese ese ese ese ese ese ese ese ert ese ert ert ert ert ert ert .aCimeeit of Phoaphoric Acid and LiquidFertilCzrt.

SolutCsiз, Srpteeber-Gitoeber 19 * 75; Achorn, F. P. - WHhggb, E. B. - Balay, li. L: CoorssCsn Probleme Can be Alleviated with Right Maaterals. F. Et al., Solutics, Ma.y - June 1976; Pratt, Ch .. J: Brrt. Chem. Engng. 16, 1971, p. 172; Kaltenbach et Gardiriier, Paris: Chem. IIG. Techn., 42,19 * 70, δ. 24, š. 2,309; Kooiarevski, I .: The Amelenium Polyphosphates and Liquid Pdductioi from 52 to 54%. Phosphoric Acid. In: Proceedings of the 11th Annual International Symposium on Fertilizers. UNIDG. Vienna 1971.

Clogging of KFA in liquid fertilizer technologies of the solution type, it was possible to increase the yield of the products from the original 26-32% to 44-48% of the amount of frequent nutrient (N + P + G + +). A precondition for the preparation of mite liquid fertilizers with an even higher content of paste nutrients is a higher proportion of linearly condensed phosphates (mainly the content of barium and oorosinans) in the melt used in the preparation of fial products (Siegel, M.R. - Young, R. D.: Polyphosphates

- Part II - Base Maaterals.

Farm No 3, 132, 1969, p. 9, p. 41). Efforts to achieve the highest possible content of linear KFA in the products of the reaction of phosphoric acid with ammonia gas are also influenced by agrochemical and agronomical reasons. International Congress of Mineral Fertilizers (Section 7), Moscow 1976, Isao Hashimoto -

- Lehr, JR: МоМШу of Polyphosphates ii Sooi. Sooi Sci. Soc. Am. Bmc ,, 37 (1973), δ. 1 (January-February), 36-41; Khasawneh, FE - Samppe, EC - Ysao ΗββΗ ^ ο ^: ReactCons of Aimmnium Grtho - and PolyphospHa ^e Fertilizets ii SoH: MoMllty of Phnsjphorus. Soil Sci. Soc. Am. Proc., 38, 19 * 74, š. 3 (May-I), 446-451; Termen, G. L: Agronomy of Resuuts with Polyphosphate Fertil Czets. Phosphorus Agrrc., 65, 1975, sept., To 26; Sai ^e, EC-Sopeir, RJ-Racz, C. F: Resa ^ of PllospHa'tr Feetilizers ii soils. The Role of Phosphorus II Ag ^^^ ure, Chapper 11. Am. Society of Agronomy, Inc., Crop Sel Soc. of America, Inc., Salts of Science Society of America, Inc., Madison Wsconsln 1 ^ 80), by the possibility of using liquid NP fertilizers as a base component in production | stable suspension fertilizer (achorn, F. p .: Fert. Solutions, 20, 1976, no. 1, p. 72) also characterized the possibility to use supine sequestration properties for administration of trace elements _((Achorn FP - Scott, WC: Polyphosphates Are Revolutionizing Fertillzers - Part III - Polyphosphates in Mixtures, Farm Chemicals, 132, 1969, 2, 12; Huffman, E. 0. - Newman, EL: Polyphosphates Are Revolutionizing Fertilizer - Part IV - Behavior and Outlook.

Farm Chemicals, 133, 1970, no. 2; Mortvedt, J.J. et al .: Mocronutrients in Agriculture. Madison, Wisa, USA. Soil Sel. Soc. of America 1972; GOR-NAGY, S. Káldi, P. - Bésán, J. - Szánto, A .: The Solubility of Micronutrients in Ammonium Polyphosphate Solutions. Hung. J. ind. Chem. Veszprém, 1978, 6, p. 259-274).

In the context of the development of KFA production processes based on neutralization-dehydration reactions between H 2 PO 4 and ammonia and in connection with the disruptive application of these technologies in production practice, it appears to be particularly advantageous to deepen molecular dehydration by chemical condensation agents.

Furthermore, an improvement in the development of direct KFA production processes is a method of manufacture according to the invention.

SUMMARY OF THE INVENTION The present invention provides that a melt containing condensed ammonium phosphates is formed by reacting trihydrogenphosphoric acid at a concentration of 32-64% P10 and a temperature of 5-150 ° C, or a solution of ammonium dihydrogenphosphates in trihydrogenphosphoric acid with ammonia gas.

The neutralization / dehydration reaction proceeds under conditions in which the mean specific gravity of the liquid reagent containing trihydrogenphosphoric acid is at least 1.5 times higher than the mean specific gravity of the heterogeneous reaction mixture in the reaction medium, wherein the liquid phase containing the phosphorous phosphoric acid. reacts with sulfur oxides by reaction with ammonia and / or a neutralization-dehydration reaction between the phosphorus-containing liquid phase and ammonia in the presence of sulfur oxides and / or in the presence of their polymerization or hydration reaction products. Molecular dehydration of the liquid-melt phase thus prepared. it may be further exacerbated by its reaction with urea.

Sulfur oxides (in particular sulfur trioxide in all states and modifications), products of their polymerization reactions (eg cyclic molecules of trimer S ^ O ^ represented in the liquid state, linear chains of SO2 molecules, variously stabilized sulfur trioxide which does not increase its freezing point commercially) known as SULFAN ”), as well as the products of the hydration reactions of sulfur oxides, are very vigorously combined with water.

In addition, all of these reactions are markedly exothermic, which positively affects the course of thermal dehydration, eg:

SOj (g) + H ₂ 0 (1) ---------- * ^H 2 ^SO 4 ^лН ° 298,15 ⁼ - '> 3O3 8,10 ⁵ J (-31,14 Jccal)

SO ₃ (1) + H ₂ 0 (1) ----------- 'H ₂ ^SO 4 ^{(1) δ H} ° 298.15 ⁼ - ^β · ^{75β 8} ·' ° ^{4 J} (- 20,92 kcal)

The high water affinity of these compounds is only manifested by the charring of organic substances.

23Ί462

Reaction of sulfur trioxide with ammonia in anhydrous state? depending on the reaction conditions, sulfuryl amide (sulfide) and sulfuryl imide (sulfimide) are formed according to the equations; .

I S0 ₃ + 2NH3 ----------> S0 ₂ UH _? ) ₂ + H 10

SO ₃ + NH ₃ -----------> SO ₂ (ii) + H ₂ 0.

In the presence of sulfuric acid, the sulfuryl imide can also be further polymerized to form chain-like polysulfurylimidosulfonic acids, HO-SCO- (NH-SO ₂ ) _n, resp. their ammonium salts. To the moleknuárnej debyddatácii ammonium phosphate in řtudovanom system excluding moonnoť over the height of said, neSiadúcich vedrajřich reakecí, it is necessary to adjust the reaction conditions so as to avoid the contact of the sulfur trioxide with the ammonia in bezvědom environment (the sulfur reactants are added BuA the liquid fCzy obsahujécej H ₃ PO ₄ before its reaction with ammonia, or add this to the cautality of the C0-dehydrated reactor, where the presence of deethylldate (with phosphorus reactant) is already guaranteed).

Method of preparation. condensed ammonium phosphorus neutrality by the co-dehydration reaction of H 2 PO 4 recp. solution of ammonium dihydrogen phosphates in ammonia gas in the presence of sulfur oxides, or in the presence of the products of polymerization or hydration reactions of these oxides, has a number of foresters compared to the KFA preparation processes used today. They may include at least the following:

- H3PO4 with a higher water content can also be used to prepare KFA without the need to pre-concentrate, thereby substantially reducing the energy and investment costs of the process;

A

it is not necessary to pre-heat the phosphoric acids used for the preparation of KFA to high temperatures, thereby substantially reducing the demands on the use of special corrosion-resistant materials in the process of producing KFA;

the process makes it possible to process different types of H 3 PO 4 (extraction black and green acid, thermal acid);

The formation of inclusions on the walls of the carbon-dehydration reactor is substantially reduced as a result of the presence of cationic and anionic impurities in the process.

the sulfur content of the product of the deutration-dehydration reaction significantly changes its properties (the amorphous nature of the melt disappears) and this is suitable for the preparation of high-quality granules;

the reaction product is enriched with a highly important secondary peat nutrient - sulfur.

The following examples illustrate but do not limit the invention.

Example 1

During this continuously conducted Quartz-run experiment, we verified the method of preparing condensed ammonium phosphates according to the invention in conjunction with the preparation of concentrated NPS - suspension type liquid fertilizer.

We have been working with extraction H 2 PO 4. of green type, prepared from calcined phosphites, which, according to the photometric assay, contained 47.8 wt. % of the total? 2θ5 * in the continuous modeling apparatus set, we used a vertical flow-through film, start-up, short-circuiting reactor in the sense of PV 1016-82 with a concurrent flow of liquid and gaseous phases of the reaction mixture from top to bottom.

The overall height of the reactor body was 1,000 mm and its internal diameter was 120 mm.

An organized filler consisting of 9 rows of 50 mm in diameter ring rings was placed on the perfodoaan load-bearing bottom of the reactor, followed by a layer of 12 mm ring-shaped rings filled with a 30 mm thick ring ring, with a relatively narrow loose layer on top. sprinkled rings of different diameter forming so-called. distribute the reactor packing layer. The reactor body and its packing were made of impregnated graphite. The inlet of the phosphoric acid-containing liquid reaction components as well as the inlet of ammonia gas flowed above the filler layer.

The treated phosphoric acid to be treated is dosed via a peristaltic-tubing metering pump from a reservoir of acid fused to a gravity scale, through a tube heat exchanger heated with low pressure water vapor to the reactor.

Sulfur dioxide gas, which was obtained from about 30% oleate, was bubbled through a column of acid-containing gas in a vertical tube just prior to the inlet of the acid into the reactor. The reaction of the feed with sulfuric oxide was vigorous, accompanied by a hissing mixture. .

An average of 52.4 kg of extraction H 2 PO 4 (47.8% PgO 4, Ю-5 kg of SO 3 gas and 13.6 kg of gaseous ammonia) was metered hourly. about 15% of a suspension of sodium bentonite, prepared continuously in accordance with the Czech Republic ^No. (PV ^No. 2800-80, in the range of approx. ^7.0), was continuously fed through the perforated support bottom of the reactor body into the dissolution reactor into the early stage. ^the gh ^- '. the temperature of ^the rea zmeei stand out in the reactor rozpiúštacom ^^ Laval the circulation through the condenser at 65 to 75 ° C. the complete binding of a feed gas in a reaction zloíiek product is ensured by scrubbing the gas phase of the liquid mixture, with slightly acidic reaction in the spacing of the absorbent column.

The reaction product - a suspended NPS fertilizer, characterized by a 13.4-30-30-5S composition, continuously discharged from the dissolution reactor through a liquid cap and collected in a process product container. The product was characterized by very favorable handling properties, good storage, weak acid reaction (pH of the undiluted suspension ^6, 5) and at. temperature ²⁵ ° C containing ¹ to ^{7 kg} I.8 U.S. ^tp and ^d; 418 .mu.g of ^PgO4 and 70 kg of sulfur in full plant and inimitable form. More than 55% of the total in suspension! the phosphorus was present in the polysensated form. Chromatographic analysis on a cellulose thin layer revealed that the maximum condensation degree of phosphorus in the reaction product responded to phosphorus (n = 4).

Although the solid phase content was not directly determined in the prepared fertilizer suspension, it can be assumed that the proportion of solid-suspended particles in the fertilizer was not more than 18 wt. %. The fertilizer showed complete suspension stability even after some weeks of storage, and a sample of the product was completely resuspended for one gradual rotation of the sedimentation roller. The dynamic viscosity of the suspension fertilizer at 20 ° C was 0.215 Pa.s.

Example 2

In a several-hour continuous guided experiment on a model apparatus, a vertical sieve neutralization reactor was operated using a gas-phase liquid phase layer in the sense of Cs. AO č. 210 335, chai * accelerated by the following geometric parameters:

- total length of the reactor body - inside diameter of the reactor body the ratio of the internal cross-sectional area of the reactor body at the location ¹ 000 mm 125 mm

overflow of the reaction mixture (Fj to the flat internal cross-section of the reactor body at the mouth of the phosphoric acid inlet (F ₂ ), Ff = ¹

- distance of supply H-PO ^ from

the distance of the overflow of the bottom reaction reactor body from the top cap

- height of the partition (annular shape) separating the incoming orifice of the feed tubes of the gaseous reactants from the phosphoric acid inlet

- the distance between the orifice of the conscious sulfur dioxide tube from the bottom of the reactor body

- distance of the orifice of the coaxial pipe for the ammonia gas inlet from the bottom of the reactor body mm

100 mm

200 mm mm

160 mm.

The reactor body as well as the reactant gas inlet tubes, the separating annular baffle, the H 2 PO 4 inlet and the reaction mixture outlet were made of impregnated graphite. Moreover, the parts of the technological equipment used are in accordance with the condition given in example no. First

To the neutralization-dehyeratogenic reactor operating with the gas phase layer bubbled with a gas of the above-mentioned design, we continuously metered on average in a minute:

071.0 g of a black tri-trihydrogenphosphoric acid extract containing 53 53.8 wt. % of total Pg®5>

180,5 g of sulfur trioxide gas and

286.8 g of ammonia gas.

The temperature of the H tPO PO feeds at the inlet to the neutrino-dehseride reactor fluctuated during the experiment in the range of 43-65 ° C. The gaseous reactants were introduced into the reactor at a temperature close to the temperature of the molar mass. The reaction mixture left the neutralization-dehydration reactor at 244-252 ° C. We bubbled almost minute into the dissolution reactor. 5 ²¹ 9 · cm ^ of water.

Under the given conditions, we have obtained about 90 liters resp. 123.6 kg of solution quail liquid fertilizer characterized by the composition 11.4 - 28.0 - 0 - 3.5 S, whose pH (undiluted product) was 6.3 to 6.7 and the specific gravity at 20 · ° The liquid fertilizer contained more than 60% of phosphorus leached in the form of linearly condensed phosphates.

A sample of liquid NPS fertilizer retained good flowability and rheological properties after monthly storage in an freezer at an average storage temperature of -17 ° C.

Example 3

In this experiment, a modified neutralization-dehydration reactor operating with a gas-phase liquid phase bed was used, with a liquid phase of the reaction imission flowing along the outer part of the reactor body in a continuous nail sinking helix (Se. AO Nos. 205,849 and 216,856, respectively). ).

In addition to the spaced tubes serving on the inlet 8 (similar to the experiment described in Example 2), a 120 mm bottom edge of the overflow of the reaction mixture formed a vertical molten urea inlet pipe. With it, the reaction mixture was heated with a tooth-puffing pump dipped with elaine of molten urea in its melting tank, and the urea was dosed, which served as a condensation agent in the melted system.

During a few minutes of the experiment, we took an average minute-long dose of:

100 g of partially concentrated extraction H 2 PO 4 containing about 38% total. PGO ^>

174 g of sulfur trioxide gas,

198.2 g of ammonia gas and

70.0 g of molten urea.

Under smoked conditions, an average of 89.6 kg of liquid NPS-hHE was obtained with the composition: 11.6 - 28 - 0 - 4.7 sec.

The liquid fertilizer contained 26% phosphorus bound in condensed form, while 5.7% of the total nitrogen content was bound in amide form.

A sample of liquid NPS fertilizer retained good fluidity and satisfactory rheological properties even after a month's storage in the freezer at an average storage temperature of -17 ° C.

Claims (1)

Example 3 In this experiment, a modified neutralization-dehydration reactor working with a liquid-phase gas-bubbled layer was flown with a liquid phase flow of the reaction mixture on the outside of the reactor body in a continuous top downward slope (No. AO No. 205 849 and 216 856, respectively). ). In addition to the coaxially positioned tubes serving the inlet 8 (similar to that described in Example 2), a 120 mm below the lower edge of the overflow of the reaction mixture resulted in a vertically directed inlet tube of molten urea. Through this process, urea was fed into the hot reaction mixture immersed below the surface of the molten urea in its melting tank, which functioned as a condensing agent in the system under study. During a one-hour quarter of an experimental run, an average of one minute was dosed: 1,100 g of partially concentrated extraction containing about 38% total. PgO3, 174 g of sulfur trioxide gas, 198.2 g of ammonia gas and 70.0 g of molten urea. Under these conditions, we obtained on average 89.6 kg of liquid NPS-fertilizer characterized by the composition: 11.6 - 28 - 0 - 4.7 S. The liquid fertilizer contained 26% of the phosphorus bound in the condensed form, while 5.7% of the total nitrogen content was bound in amide form. The liquid NPS fertilizer sample retained good fluidity and satisfactory rheological properties even after monthly storage in the freezer at an average storage temperature of -17 ° C. BACKGROUND OF THE INVENTION A process for the preparation of condensed phosphonates of ammonium by reaction of trihydrogen phosphate with a concentration of 32% by weight of 64% by weight with 1 to 5% by weight of 150 to 150 ° C, or a solution of ammonium dihydrogen phosphate in ammonia with gaseous ammonia. conditions in which the mean weight of the liquid reactant containing trihydrogenphosphoric acid is at least 1.5 times higher than the mean density of the heterogeneous reaction mixture in the reaction medium, characterized in that the liquid phase containing the trihydrogenphosphoric acid is treated with ammonia reacting with the sulfur and / or neutralizing-dehydration reactions between the phosphorus-containing liquid phase and the ammonia in the presence of sulfur oxides and / or in the presence of products of their polymerization or hydration reaction, wherein m molecular dehydration of the thus prepared liquid-phase melt phase of the reaction mixture and possibly further aggravate it by reaction with urea. 1