SU916389A1 - Process for producing sodium ammonium phosphate - Google Patents

Description

The invention relates to the technology of sodium ammonium phosphate (NAF), which is used as aggtipyrene, mineral supplements for ruminants, as well as to obtain sodium tripolyphosphate.

A method of obtaining sodium ammonium phosphate by the interaction of acidic sodium phosphate with ammonia. The process is carried out at 90 * 95 * C in the sodium phosphate melt [1].

The disadvantage of this method is its complexity due to the need to maintain a high temperature.

There is also known a method of obtaining ammonium sodium phosphate, including the sequential processing of phosphoric. acid soda and ammonia first to pH (, 5 "3.0, and then to pH 3-6 with separation of precipitates formed at each stage. The resulting solution is treated with soda. After cooling the resulting pulp to 20 ^° C, separate

2

product sediment, and the mother liquor is returned to the stage of processing soda C2].

The disadvantage of this method is the need for consistent introduction of reagents and, consequently, a multi-stage process, increased consumption of reagents for the deposition of impurities, as well as high temperature process. with

The purpose of the invention is to simplify the method by reducing the number of Operations, reducing the consumption of reagents and reducing the process temperature.

This goal is achieved by the fact that in the method of obtaining sodium ammonium phosphate, including the interaction of phosphoric acid with ammonia and soda, followed by separation of the product sludge and returning the mother liquor to the interaction, phosphoric acid serves the interaction dissolved in an organic solvent, and the reagents serve

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at the same time.

These differences make it possible to reduce the process temperature to 15 ° C, reduce the number of operations by eliminating precipitation and separating impurities, and reducing soda consumption for fluorine precipitation by 3 ~ 51 kg / ton of acid and ammonia for precipitating impurities by 4.8-18 kg / t acid.

Diammonium phosphazt can be used as a source of ammonia in the preparation of sodium ammonium phosphate.

PRI me R 1. To a 75% solution of tributyl phosphate (TBP) in kerosene, containing 91> 4 g / l of phosphoric acid, obtained by extraction of phosphoric acid, add 0.4 l / l of the crystallization mother liquor of NAF having the next composition

· Wt.%: P ₂ 0 / 9,12; Ma _£ 0 2.84; N2.73SM at 15 ° C is treated by simultaneously feeding an aqueous suspension of soda 17.5% Ma _g C0 _a ) and an aqueous solution of ammonia (27.3% MN _g ) taken in stoichiometric amounts, Reg-; & Unirected 75% TBP is decanted; the crystalline NAF is filtered from the mother liquor and dried. Get NAF ί in the amount of 72 g / l of a mixture of the following composition, wt.%: R _g 0 ₅ 33.5; .

Ia _g 0 14,6; N 6.6; H ₂ 0 34; 50 ₃ 0.2; ^thirty

Reg.0 _$ 0.802; A1 ₂ 0 _a 0.802; P 8,015;

510 _g 0.01. The mother liquor obtained in the amount of 0.6 l / l of the mixture is partially returned to the interaction.

PRI mme R 2. In the mixture of TBP in 35

phosphoric acid kerosene according to Example 1 is added with a stock solution (0.21 l / l of the mixture) and treated with soda (46 g / l of the mixture) and a solution of diammonium phosphate (0.26 l / l of the mixture) 40 containing 31.9 wt.% salt , at 20 C. At the end of mixing, the formed pulp is settled and divided. The crystalline NAF is dried; its yield is 29 g / l 45

mixes. The composition of the product is the following wt.%: P _g 0 ₉ 33.7; Νθ ₂ 0 14, ~ 6; N 6.4; H _g 0 35; 50 ₃ 0.3; p 0.01. The output of the mother liquor is 0.46 l / l of the mixture. .

PrimerZ · A mixture of butanol with phosphoric acid (66 g / l), a suspension of soda (17.3% Pa ^ SOD), an aqueous solution of ammonia (27% ΝΗ ₃ ) are simultaneously poured into a mother liquor, taken in an amount of 0.9 l / l mixes. The treatment is carried out at 30 ° C. After settling, separation, filtration and drying, crystalline NAF is obtained in the amount of 155. g / l of a mixture of the following composition, wt.%: P _£ Od 33.6; By ₂ o 14.5; N 6 _L 6; H ₂ 0 33; 50 ^ 0.1;

P 0.015 and 0.33 l / l of mother liquor, containing 6.91% 1 and 2.02% Ia ^ O, which is returned for processing.

Thus, the proposed method allows to simplify the process, reduce energy consumption and consumption of reagents.

Claims (1)

Claim The method of obtaining ammonium sodium phosphate, including the interaction of phosphoric acid with ammonia and soda, followed by separation of the precipitate product and returning the mother liquor to the interaction, which differs by the fact that, in order to simplify the method by reducing the number of operations, reducing reagent consumption and reducing the temperature process, the interaction serves phosphoric acid dissolved in an organic solvent, and the reagents are served simultaneously.