SU806660A1 - Method of producing concentrated nitric-phosphoric fertilizer - Google Patents

Description

; 54) METHOD FOR OBTAINING CONCENTRATED NITROGEN-PHOSPHORO-FERTILIZER

one

The invention relates to the field of production of chemical fertilizers for agriculture and can be used in the preparation of concentrated fertilizers.

A known method for producing a concentrated fertilizer by dehydrating ammonium orthophosphates at 1,75400 C1.

The disadvantage of this method is that even when complete dehydration is not achieved and the final product contains up to 15% ORTO form relative to its total content.

The closest in technical essence and the achieved result to the proposed method is to obtain concentrated nitrogen-phosphorus fertilizer by thermal dehydration at 100-120 ° C, for an hour, ammonium orthophosphate containing 25-27 mol.% G27 carbaMID.

The product obtained has the following characteristics, wt.%:

N -19.7-30.6

one . 6.0-15.0, ammonia 7.2-23.4

N

alchina

31.0-51.0 l ° 5 abundance

The conversion degree (polyphosphate content) is up to 72.4%, the Pestov hygroscopicity is 5.6.

The disadvantage of this method is the decomposition with loss of ammonia of the original ammonium orthophosphate, the low content of ammonium polyphosate in the obtained Fertilizer, the duration of dehydration in the specified temperature range, and the hygroscopicity of the fertilizer is high.

The purpose of the invention is to prevent decomposition of the starting ammonium orthophosphate, increasing the content of poly5 ammonium phosphate in the resulting fertilizer, intensifying the process, as well as reducing the hygroscopicity of the fertilizer.

The goal is achieved by

That the mixture of ammonium orthophosphate with carbamide is subjected to thermal dehydration under the pressure of agf1lac from 2 to 6 atm at 110-140 ° C.

Example 1. 99 g of orthophosphate

5 ammonium (75 mol.%) And 15 g of urea {25 mol. %) are mixed, the mixture is homogenized and placed in an autoclave where ammonia gas is supplied. Upon reaching the required ammonia pressure for the study of ammonia, 2 atm

its feed is stopped and the autoclave is closed tightly. It is then placed in an oven, where the mixture in the autoclave is heated to, the reaction time is 0.35 hours,

Under the conditions of Example 1, examples 2, 3, 4, 5, 6 are carried out, and the results of the Tfcj tests are presented in the table.

Thus, the method allows to obtain chemical fertilizer with a relatively high content of nitrogen and phosphorus, wt.%:

O5sh, iy2 S, O-36, O

| ammoniac 9.0-18.9 amidium6.1-2 7., O

Pa05bs.iy22,7-44,8

With a high content of polyforms in the product, the degree of conversion (content of polyforms) оС - 87-100, hygroscopicity decreases to 0.08-1.4 points, decomposition of the starting ammonium orthophosphate stops, since the nitrogen content in the product completely coincides with the theoretically calculated.

Claims (2)

The method of producing concentrated nitrogen-phosphorus fertilizer by thermally dehydrating a mixture of ammonium orthophosphate with carbamide, characterized in that, in order to prevent decomposition of the starting ammonium orthophosphate and increase the content of ammonium polyphosphate in the obtained fertilizer, to intensify the process, as well as to reduce the hygroscopicity of the fertilizer, thermal dehydration carried out under ammonia pressure from 2 to 6 atm at 110-140 ° C. 5Q Sources of information taken into account in the examination. 1. E, Kobayashi J. Chem. Soc. Japan Pure Chem Sec., 1964, v. 85, No. 8. . 2. Norchaeva O. P. et al. On the mutual · 55 action of monoammonium phosphate and urea when co-heated. Journal of Applied Chemistry, vol. XL IV, No. 2, 1971, pp. 233-239 (prototype). VNIIIPI Order 167/39 Circulation 456 Subscription Branch Patent Patent Uzhhorod, st. Project, 4