CS260159B1 - The method of neutralizing the trihydrogenphosphoric acid and the apparatus for carrying it out - Google Patents

Abstract

Neutralization of trihydrogenphosphoric acid with ammonia was carried out by circulating mixed solution of ammonium hydrogen and/or dihydrogenphosphate with addition of trihydrogenphosphoric acid at pH 1 to 7.5 in the diffuser of the liquid jet ejector. Ammonia contains water vapor in a molar ratio of 1:0.1 to 1:3. The device for carrying out this operation is a liquid jet ejector, the nozzle of which is connected to the circulation tank by a circulation pipe and a pump, the process vapor pipe is connected to the inerts outlet pipe via a process vapor condenser and the process condensate drain is connected to the circulation tank by a process water connection pipe. The diffuser is connected to the water vapor pipe and/or the process vapor connection pipe.

Description

260159

The present invention relates to a process for the neutralization of trihydrogen phosphate with ammonia and to a device for its implementation.

The ammonium salts of trihydrogenphosphoric acid, in addition to ammonium nitrate and urea, are important inorganic salts. They have wide application in the production of fertilizers, both solid and solution, as liquid fertilizer and suspension. The technological preparation ensures by neutralization of the trihydrogen phosphoric acid with ammonia or ammonium acacia water, according to the method of preparing the phosphates, the usual reaction vessels provided with a stirrer in one or two stages with a direct inlet of gaseous or liquid ammonia and water to control the output concentration. Solutions based on the principle of spray columns are known, whereby a trihydrogenphosphoric acid is sprayed in a two-stage process known as the Otto process in the process of direct mixing of phosphoric acid. It is a known method of direct mixing of phosphoric acid in a direct spray vortex reactor such as the so-called GARDINIER process. Industrially, it has found widespread application of the so-called tubular T reactor, as a mixing element with direct injection of acid and ammonia into a reaction zone formed by a tube, supplemented with a separator and an effective scrubber of aerosol exhalates. These systems, or combinations thereof, are disclosed in the literature published by the Applicant, as well as U.S. Patents 3,813,233; 3,775,534. Said systems, when used in the preparation of liquid NP solutions from commercial sources. Extract acids containing contaminating impurities, particularly iron and aluminum, provide solutions in which the insoluble phosphates are formed by neutralizing, thereby depleting, thereby reducing the utility value of the products due to fouling of storage tanks, conveying pipes, application techniques which are characterized by so-called fluidity, as a percentage of sediment residue from the total volume over a given time. This reaches 3% and higher. As a result, additional stabilizing additives, usually activated bentonite, as well as other substances that slow down the sedimentation process are needed.

It has been found that this problem can be solved by the process of neutralization and by the device according to the invention, the principle being that neutralization with ammonia is carried out by circulating a mixed solution of hydrogen and / or di-ammonium phosphate with the addition of trihydrogen phosphate at pH 1 to 7.5 in the diffuser of the dripped ejector. The ammonia contains a molar ratio of 1: 0.1 to 1: 3. The apparatus for carrying out the method characterized in that the liquid jet nozzle is ejected by the circulation pipe and the pump connected to the circulation tank, the process steam pipe is on the outlet pipe the inerts connected through the process vapor condenser, the process condensate condensate is a tubular overflow of process water connected to the circulation tank. The diffuser is connected to a water vapor pipe and / or a process steam coupling pipe.

The method and apparatus of the invention produce reaction conditions in a turbulent flow with a gradual neutralization process, thereby obtaining solutions which, even without the addition of stabilizing additives, are sufficiently stable, with the possible sediment being readily dispersible. It does not require tailor-made replenishers for aerosol exhalation even when neutralization takes place in one step and at higher circulating solution concentrations.

The attached figure shows a schematic arrangement of the individual elements according to the invention.

The circulation tank 1 is a circulating pipe 11 and a pump 6, a solution cooler 18 connected to the liquid jet nozzle 3 of the reactor 2. The liquid jet diffuser 4 is connected to the ammonia inlet pipe 13, the water vapor pipe 21 and the process steam transfer pipe 20. The circulation tank 1 is provided with a solution outlet pipe 12. Process pairs leave the circulation tank 1 through a process steam pipe 8 via a process steam condenser 5. The non-condensed fraction leaves the tube 18 of the iner outlet. The process water enters through the process water supply pipe 7 and is coupled via the process condensate discharge 17 from the process steam condenser 5 through the pipe connection 9. The circulation pipe 11 is coupled to a 10-trihydrogen phosphoric acid pipe. The cooling solution 18 and the condenser 5 are connected to the cooling water inlet 14 and the cooling water outlet 15. In the case of the preparation of high-concentration supersaturated solutions with the addition of additives, these can be passed through the pipe 19 into the circulation pipe 11. In the case of particularly high the requirements of ecological pollution, the tube 16 of the iner outlets may be connected to a sanitation absorber of conventional construction types. Přikladl

114 m3 / hour was circulated through the liquid ejector. ammonium hydrogen phosphate and dihydrogen phosphate solution. The initial pH was between 1 and 1.2 and the temperature between 63 and 64 ° C. At the same time, process water was injected into the circulation tank at 1.5 to 2.5 m3 / h. depending on the specific gravity of the solution and the circulating solution of 1 to 1.8 m 3 / h. Extractive trihydrogenphosphoric acid. The liquid ejector diffuser was added with a mixture of ammoniacal vapor and water vapor in a molar ratio of 1: 2, which

Claims (4)

The step was adjusted to a molar ratio of 1: 0.15. The temperature of the solution was maintained at 63-67 ° C. The pH gradually increased to a value of 7.4. A solution of 1210 kg was obtained. cm-3 with a content of 7.9 wt. N and 19.4 wt. citrate-soluble P2O5. The acid used contained 54.2 wt. P2O5; 1.83 wt. R2O3; 2.9 wt. H2SO4; 0.11 wt. % of oxidizable impurities and 1.34 wt. sedimenting particles. EXAMPLE 2 Trihydrophosphoric acid extraction composition 53.3% by weight was injected into the circulated solution with an initial pH of 1.5 liquid-jet ejector as in Example 1. P2O5; 1.8 wt. R2O3; 3.6% wt H2SO4; 0.12 wt. % of oxidizable impurities, 1.04 wt. sediment, the process water and the diffuser of the liquid ejector were fed with a mixture of gaseous ammonia and aqueous vapor with a molar ratio of 1: 1.9 to 1: 2.9. The circulated solution was maintained at a temperature range of 66-87 = C. The pH gradually increased to 6.7. The addition of process water was regulated according to the specific gravity value, which reached 1,390 kilograms. cm-3, when the solution is 35.6. wt. P2O5; 13.1 wt. N. By adding process water, the specific weight of the solution was adjusted to 1262 kg / cm < 3 >. EXAMPLE 3 To a circulating solution having an initial pH of 1.2 of the liquid ejector, as in Example 1, a trihydrogen phosphate extraction acid of 53.6 wt% P2O5, 1.49 wt% R2O3, 2.9% was injected. 0.55% by weight of sediment, 0.01% by weight oxidizable substances, process condensate, and a mixture of vapor of ammonia and aqueous vapor in a molar ratio of 1: 3 was added to the liquid-jet diffuser. at a temperature of 70 DEG-90 DEG C. The pH was gradually increased to a value of 6.7 and a specific gravity of 1322 kg / cm @ 3, a solution having a composition of 10.4% by weight, 27.6% by weight of P2O5, continuously withdrawing from the circulation tank and after adding the process condensate to a final composition of 9.1% by weight N, 24.2% by weight P2O5. of the solution to be prepared was 2.4 ° C A process for the neutralization of trihydrogenphosphoric acid with ammonia, characterized in that the neutralization with ammonia is carried out by circulating a mixed solution of hydrogen- and / or di-ammonium phosphate with the addition of trihydrogenphosphoric acid at a pH of 1 to 7.5 in the liquid-jet diffuser. . 2. Process according to claim 1, characterized in that it contains water vapor in a molar ratio of 1: 0.1 to 1: 3. 3. Apparatus for carrying out the method according to (1) and (2), comprising a circulating tank, a liquid ejector, a condenser, a pump and a transfer tube, characterized in that the liquid-jet nozzle (3) is a circulating tube (11) and the pump (6) coupled to the circulation holding vessel (1), the process vapor pipe (8) is an inert exit dump (16) via the process pair condenser (5) and the process condensate outlet (17) is a process water pipe (9) connected to by a circlip tank (1). 1 Device according to claim 3, characterized in that the diffuser (4) is connected to a water vapor tube (21) and / or a process steam connection tube (20). 1 sheet of drawings