RU1792932C - Method of modification of ammonium nitrate with magnesium nitrate solution - Google Patents

Abstract

Use: for the preparation of non-caking granular ammonium nitrate. SUMMARY OF THE INVENTION: 56-58% nitric acid is mixed with a 20-50% solution of ammonium nitrate in a mass ratio of HMOs MH4MOs 1.0: (0.6-1.0), the magnesite is decomposed with the resulting mixture, filtered, introduced the solution was dissolved in the melt of ammonium nitrate, evaporated, granulated and dried the finished product. 1 tab.

Description

FIELD OF THE INVENTION This invention relates to techniques for the preparation of non-caking granular ammonium nitrate with the introduction of a modifying agent into the process.

The purpose of the invention is to reduce the amount of water introduced into the solution or melt of ammonium nitrate along with a solution of magnesium nitrate.

Examples of the method.

Example 1. 74.6 parts by weight 56% nitric acid is mixed with 46.6 parts by weight of 20% of the foot of a solution of ammonium nitrate (ratio HNOarNH / jNOa 1: 0.62). 20 parts by weight of solution are added to the prepared mixture, magnesite and be kept for 20 minutes with constant JM stirring. The suspension is filtered to obtain a solution of magnesium nitrate and 4 parts by weight of insoluble residue. The filtration performance of the filtrate is 0.21 m3 / m2 h, according to the known method, the suspension is practically not filtered5, The amount of water introduced into the production of ammonium nitrate together with

magnesium nitrate, reduced by 9.63% by

Compared to the prototype. . Example 2. 74.6 May, hours 56% nitric acid is mixed with 44.6 parts by weight of 50% solution of ammonium nitrate (ratio HN03: NH4N03 1: 0.6). Into the prepared mixture of solutions was introduced May 20, h. magnesite and incubated for 20 minutes with constant stirring. The resulting 139.2 parts by weight, the suspension is filtered to obtain 4 parts by weight insoluble residue and 135.2 may, hours magnesium nitrate solution. The filtration performance of the filtrate is 0.08 m / m h. The amount of water introduced into the process with magnesium nitrate is reduced by 29.2% compared with the prototype.

Example 3. 74.6 parts by weight 56% nitric acid is mixed with May 55.95, h, of a 50% solution of ammonium nitrate (LN4MOS: HMOS ratio 1: 1) - 20 parts by weight are added to the prepared mixture of solutions. magnesite and incubated for 20 minutes with constant stirring. Received 150.55 parts by weight

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the suspension is filtered to obtain 4 wt.h. insoluble residue and 146.55 parts by weight magnesium nitrate solution. The amount of water introduced into the process with: magnesium nitrate is reduced by 9.68% compared with prototrimm Productivity. Filtration by filtrate is 0.55 m3 / m2 h (see table) PacjBpp ammonium nitrate with a concentration below 20% NH4NQ3 should not be used, since the filtering properties of the magnesia additive are sharply worsened, and the amount of water introduced into the process along with the additive increases (experiment 9). An increase in concentration above 50% NH / iNOa leads to an increase in) the viscosity of the suspension and its deterioration)

FILTERING PROPERTIES (EXPERIENCE 10). ,,:

The mass ratio of LNOZMNzMOz is lower than 1: 0, b is not recommended because the filtration performance of the maize suspension sharply decreases at 0.05 m / m-h at a ratio of 1: 0.5 and 0.25 m3 / m2 h - at ;; mercury 1 : 0.75, however, the largest reduction in the amount of carbon introduced into the process is observed. An increase in the maize ratio .- is higher than 1: 1 non-integer Esobord-3 Nb because in this case it is sharply increased: the amount of water introduced into the process is increased. The decrease in the amount of water introduced with the magnesian additive is only 6.4% (experiment 5) compared with the base Optit, i.e. without the addition of a solution of nitrate i.MONIA. . ; . - ..- .-; -

... Formula and sampling.

Modification method; ammonium nitrate with a nitrate solution. Magnesium, including decomposition of magnesite, nitric nitrate, filtration of a solution of magnesium nitrate, introduction of a solution of magic nitrate: in a solution or plat: ammonium nitrate, evaporation, granulation and drying of the finished

The decomposition of caustic magnesite cannot be carried out with strong nitric acid (56-58% HMO3) due to the formation of Mg (N03) 2 6Н20 or Мd (НОз) 2 7Н20, which leads to thickening and setting of the suspension, and therefore to the inability to pump and separate it from insoluble impurities. :

In order to prevent the formation of crystalline hydrates of magnesium nitrate in the known method, the nitric acid is diluted with a large amount of water in the form of a juice vapor condensate. As a result of this, with a magnesia additive, a significant amount of ..hd is added to the ammonium nitrate solution, which must then be evaporated from the ammonium nitrate solution. .

It is known that moisture during cooling of ammonium nitrate melt has a decisive influence on the sequence of modification transitions. Moisture reduction slows down polymorphic transitions, which is one of the main conditions for obtaining a product with good physical properties (obtaining strong granules).

 When implementing the method of modifying ammonia, saltpeter according to the proposed method, water is introduced into the process together with the magnesian additive by approximately 18-34.% Less than by the known method, and the filtration rate of the magnesian suspension is increased several times. ; ..

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product, characterized in that, in order to reduce the amount of water introduced into the solution or melt of ammonium nitrate together with a solution of magnesium nitrate, and better than its filtering properties, 56-58% nitric acid is mixed with 20- 50% solution of ammonium nitrate in a mass ratio of HNOs: NH4N03 1.0: 0.6-1.0.

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Table continuation

Basic experience corresponding to the conditions of the prototype.