SU567712A1 - Method of manufacturing complex fertilizers - Google Patents

Description

one

The invention relates to methods for producing complex fertilizer by acid decomposition of phosphate raw materials.

A known method of obtaining a complex adjustment by decomposing a phosphate raw material with mineral (nitric) acid or a mixture of 1.LOSLOTA, followed by ammonization of the resulting pulp and we introduce various additives iJ.

Closest to the described method is a method of obtaining a complex fertilizer by decomposing phosphate raw material with a mixture of phosphoric and sulfuric acids, taken in excess, followed by ammonization of the resulting pulp and mixing it with mineral salts.

The disadvantages are known: the methods consist in a low coefficient of decomposition of phosphate raw materials and in the necessity of a long ripening time.

The purpose of the invention is to eliminate these disadvantages. The goal is achieved by the fact that a large fraction of phosphate raw material (apatite concentrate) in size from 25 to 0.16 mm, constituting

12-14% of the total concentrate, pre-decomposed with nitric acid and mixed with pulp obtained by decomposition of the remaining part of the small fraction from 0.16 to O, 6 mm of apatite concentrate (88-86%) with a mixture of phosphoric, nitric and sulfuric acids , taken in the amount of 220-230% of stoichiometric. Extraction phosphoric, nitric and sulfuric acids are taken, respectively, at a rate of 170-175%, 36-4O%, 9-18% of stoichiometric, and the process is carried out at a temperature of 6 ° -70 ° C.

Example. An apatite concentrate (39.6) of a fraction of 0.16 mm in an amount of 50 g is introduced into the mixture of acids in the stirred reactor at a temperature. The number of revolutions of the mixer is 7OO rpm (Vt / -1.8 m / s). For decomposition, 2O5.2 g of extraction phosphoric acid (hemihydrate) 46.2%, 15.95 nitric acid are placed in the reactor.

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Claims (2)

Acids with a concentration of 53.4% H / VO “and 10.2 g of sulfuric acid with a concentration of 63%. The norms of acids with respect to the stomephonic (from a monaline phosphate) to phosphoric acid are 176%, the seed water is 36.6%, sulfuric acid is 17.6%. The final decomposition product of apatite concentrate has the composition: 5sh. 39.3%, 39, I 38, gl with ft o / Y MGT 29.8%. . The decomposition coefficient, calculated from the residue insoluble in the Pt Therman reagent and equal to 0.29% PO, is 96%. The resulting pulp is processed into layers by known methods of ammo- nization, granulation, and drying. Claim 1. Method for producing a complex fertilizer by decomposing an apatite concentrate with a mixture of acids, followed by ammoniation of the resulting pulp and mixing it with mineral layers, characterized in that, in order to increase the decomposition coefficient of apatite concentrate, a large fraction of the latter in size from 25 to 0 , 16 mm, corresponding to H14% of the total concentrate, pred.,. It is decomposed with nitric acid and mixed with the pulp obtained by decomposing the remaining part of the fine (stocks ranging from 0.16 to 0.06 mm apatite concentrate (88-86%) with a mixture of phosphoric, nitric and sulfuric acids, taken in an amount of 220 -230% of stoichiometric. 2, The method according to claim 1, about tl and h and y with the fact that, extraction phosphoric, nitric and sulfuric acids are taken, respectively, in the norm of 170-175%, 36-4O%, 9 -18% of stoichiometric, and the process is conducted at a temperature of 6 ° -7 ° C. Sources of information taken into account during the examination: 1. US Patent No. 343361 7, class 71-39 of 18.O3.69. 2. Patent of Great Britain No. 1165257 l. S1L, from 24.09. 60 ..