SU1399301A1 - Method of producing ammonium phosphate - Google Patents

Abstract

The invention relates to the production of mineral fertilizers from poor phosphate phosphate, in particular ammonium phosphate. The purpose of the invention is to increase the productivity of the process. The method involves the decomposition of phosphate phosphoric phosphoric acid in the presence of sulfuric acid with a mass ratio equal to (1.0-0.5): 1 and a mass ratio of H PO is:: ICaO, MgO, phosphate equal to

Description

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The invention relates to the production of mineral fertilizers from poor phosphate raw materials.

The purpose of the invention is to intensify the process of granulation - drying of ammonophosphate.

The method involves the decomposition of phosphate phosphoric acid in the presence of sulfuric acid with a weight ratio of H2 SOA: P20g of phosphoric acid, 0.1-0.5: 1.0, and a weight ratio of HjPO:. ICaO, MgO, in phosphate, equal to 0.9-2.2: 1.0, neutralization of acidic phosphate pulp with ammonia, granulation and drying of ammoniated pulp in the presence of a reactor, which is pretreated with ammoniated pulp with respect to its retur (2, 5-20): 1 and the particle size of the retur is 0.2-250 mm,

Example 1. Phosphorite, containing 45% of the total oxides of CaO, MgO, is decomposed with phosphoric acid. The bespous ratio of phosphoric acid is 0.1: 1.0, and the ratio is 2CaO, MgO,. in phosphate equals 10

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but 2.2. Phosphate pulp is neutralized with ammonia. A 4m retour of ammophosphate with a size of 0.3-1.2 mm is treated with ammophosphate pulp at a concentration of 50% dry, taken in an amount of 10 tons, before the material is treated with a thermal agent. The ratio of pulp to retur is 2.5: 1.0. The resulting mass

Without pretreatment of the retour with ammoniated pulp and the productivity of the process is low. When the ratio of pulp to retur is less than 2.5: 1.0, the process of introducing the treated particles into the granulating, drying the product becomes more complicated and the granulation conditions of the product deteriorate — a large increase in large non-product fractions occurs. The optimal ratio between the slurry and the retur in the pretreatment stage is 2.5-20: 1.0.

In tab. Table 2 presents data on the effect of particle size on the performance of the granulator dryer.

As can be seen from the table. 2, the particle size of the retour also has a great influence on the processing of the ammonophosphate pulps into a granular product. Thus, the particle size of the retour, less than 0.2 mm, entering the treatment, leads to an increase in the total yield of dry material from the apparatus, but transporting fine particles to the place of their preliminary processing by pulp presents great difficulties, and therefore the duration of the apparatus operation decreases. and with it the average performance.

When pulp particles are processed, retur of more than 2 mm in size results in a granulation stage — drying the product — to clog up of threading devices.

dispersed in the apparatus of BGS and RKSG, 35 the formation of large non-marketable fractions and a sharp decline in the performance of the apparatus. The optimal particle size of the retur, entering the pretreatment with ammonium phosphate pulp, is 0.2–2.0 mm.

treated with heat agent, granularit and dried. The productivity of the apparatus for the finished product is 9 t / h. Vlaemov apparatus 5 t / h.

P m and m F p 2. The process is conducted as in example 1. The retur is taken in an amount of 2 tons, and the pulp in an amount of 10. The ratio of pulp to rutur is 5: 1.0. The performance of the apparatus for the finished product 7 t / h. Moisture-removing device - 45 tons 5 t / h.

Example 3. The process is carried out as in example 1. The particle size of the retour is 2 mm. The productivity of the apparatus for the finished product is 8.5 t / h. Moisture-50 eat apparatus 5 t / h.

The appropriateness of the selected interval of ratios between the pulp and the reactor is presented in Table. one.

Thus, during the pretreatment of the retour with the ammophosphate pulp, the granulation-drying process is intensified dramatically, and the increase in the productivity of the granulator-dryer depends on the ratio of pulp to retur and on the size of its particles. When the retour particles are treated with ammophosphate pulp, they practically do not dissolve. They are covered with a layer of pulp, which, drying in the current of the heat agent, increases the size of the granules. 70-90% of the dried granulated product is removed from the apparatus as a marketable product, and 10-30% is returned to the treatment with ammoniated pulp.

As follows from the table. 1, when the ratio of pulp to retur is more than 20: 1.0, the conditions of granulation of ammonium phosphate are practically the same as those of techno

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Without pretreatment of the retour with ammoniated pulp and the productivity of the process is low. When the ratio of pulp to retur is less than 2.5: 1.0, the process of introducing the treated particles into the granulating, drying the product becomes more complicated and the granulation conditions of the product deteriorate — a large increase in large non-product fractions occurs. The optimal ratio between the pulp and the retur at the stage of its preliminary processing is 2.5-20: 1.0.

In tab. Table 2 presents data on the effect of particle size on the performance of the granulator dryer.

As can be seen from the table. 2, the particle size of the retour also has a great influence on the processing of the ammonophosphate pulps into a granular product. Thus, the particle size of the retour, less than 0.2 mm, entering the treatment, leads to an increase in the total yield of dry material from the apparatus, but transporting fine particles to the place of their preliminary processing by pulp presents great difficulties, and therefore the duration of the apparatus operation decreases. and with it the average performance.

When pulp particles are processed, retur of more than 2 mm in size results in a granulation stage — drying the product — to clog up of threading devices.

5 the formation of large non-marketable fractions and a sharp decline in the productivity of the apparatus. The optimal particle size of the retur, entering the pretreatment with ammonium phosphate pulp, is 0.2–2.0 mm.

Thus, during the pretreatment of the retour with the ammophosphate pulp, the granulation-drying process is intensified dramatically, and the increase in the productivity of the granulator-dryer depends on the ratio of pulp to retur and on the size of its particles. When the retour particles are treated with ammophosphate pulp, they practically do not dissolve. They are covered with a layer of pulp, which, drying in the current of the heat agent, increases the size of the granules. 70-90% of the dried granulated product is removed from the apparatus as a marketable product, and 10-30% is returned to the treatment with ammoniated pulp.

The proposed method allows an increase in the productivity of the process by 40-80%.

Claims (1)

Invention Formula The method of producing ammophosphate, which includes the decomposition of phosphate raw materials with phosphoric acid in the presence of sulfuric acid at a mass ratio of H Q.SO: PrjO 5 (0.1-0.5): 1, and HjPQ; : ICaO, MgO,. in phosphate (0.9-2.2): 1, neutralization of acidic phobate pulp with ammonia, granulation and drying of ammoniated pulp in the presence of a retur, which is pretreated with ammoniated pulp in order to increase the productivity of the process with its ratio to the retur (2.5-20): 1 and the particle size of the retur is 0.2-2.0 mm. Table 1 The effect of the relationship between pulp and retur (P: P) on the performance of the granulation process — ammonium phosphate. The particle size of the retur is 0.2-2.0 mm 13993016 table 2 5: 1 5.0 0.15 6.0 Production varies from 5 to 7 t / h 5: 1 5.0 0.2 6.6 Productivity varies from 7.1 to 6.1 t / h