SU1756313A1 - Method of granulation of regular superphosphate - Google Patents

Abstract

The method of granulating a simple superphosphate in the presence of a retur includes moistening the mixture, wrapping it and drying the product. To increase the yield of marketable granules of 2-3 mm, the retur is divided into two fractions, one of which is 0-0.5 mm in size, is mixed with the mature starting superphosphate for 10-15 minutes, then the mixture is fed to the granulation with simultaneous introduction of a fraction of 0.5-1 mm in size, while moistening is carried out to a moisture content of 9-11%, and the coating is carried out within 4-6 min. Contains in the finished product,%: RaOb 2,4; RgObusv 20; the output of granules with a size of 2-3 mm 81-88. 2 hp f-ly, 4 tabl,

Description

The invention relates to a technique for granulating mineral fertilizers and can be used in the preparation of granulated superphosphate.

The purpose of the invention is to increase the yield of marketable fractions of 2-3 mm.

EXAMPLE 1. 200 g of superphosphate is mixed with 14 g of sifted retour 0.5 mm in size for 10 minutes, neutralized with free RAOB, and then the mixture is granulated in a drum granulator in the presence of 16 g of retur of 0.5 - 1.0 mm with moistening with steam at 60 ° C to a moisture content of 9% for 4 min. The obtained granules are dried at 105-120 ° C to a moisture content of 3.2%, cooled, classified and analyzed.

In the finished product contains,%; P2052; 2; g RaObusv 20.0; granules with a size of 1 mm 3; 1-2 mm 9; 2-3 mm 81; 3-4 mm 7; 4 mm 0, the strength of the granules 2.1 MPa.

PRI mme R 2. 200 g of superphosphate is mixed with 16 g of retur with a size of 0.5 mm for 12 min, and then the mixture is granulated in the presence of 14 g of retur with a size of 0.5 - 1.0 mm with moistening at 62 ° С to a moisture content of 10% for 5 minutes. The obtained granules are dried to a moisture content of 3.0%, cooled, classified and analyzed.

Contains in the finished product,%: RaO 2.2; P205usv 20.2; granules with a size of 1 mm 2; 1-2 mm 5; 2-3 mm 85, 3-4 mm 8; 4 mm 0, the strength of the granules 2.4 MPa

PRI me R 3. 200 g of superphosphate is mixed with 18 g of retur with a size of 0.5 mm for xJ

cl

Gj

WITH

j

15 minutes, а — then the mixture is granulated in the presence of 18 g of retur with a size of 0.5-1.0 mm with moisture content up to 11%, at 65 ° C for b min. The resulting granules are dried to a moisture content of 2.7%, cooled, classified and analyzed.

The final product contains,% Р205sezob 2.0, Р20busv 20.3; granules with a size of 1 mm 0; 1-2 mm 3, 2-3 mm 88; 3-4 mm 8, 4 mm 1, the strength of the granules 2, b MPa,

These data indicate the possibility of increasing the commercial fraction of granular superphosphate.

Justification of parameters beyond the boundary conditions is presented in Table 1-4.

As follows from Table 1, the separation of the retur into separate fractions makes it possible to obtain granules of 2-3 mm in size, 81-88%. In this case, it is advisable to vary the size of the retur particles within 0.5–1.0 mm, since a decrease in the value leads to a decrease in the amount of the main fraction, and an increase to a larger product.

Kok can be seen from Table 2, it is advisable to conduct moisture within 9-11%, since within these limits a high yield of particles with a size of 2-3 mm is achieved,

From tab. 3, it can be seen that when granulating the mixture for 4–6 min, the yield of granules with a size of 2-3 mm reaches 68–82% and the measurement of the indicated limit of variation leads to a decrease in the target fraction or an increase in the coarse fraction of 3–4 mm or 4 mm.

As Table 4 shows, the mixture of superphosphate with a 0.5 mm retra must be carried out for 10-15 minutes. The fact is that this retur has a moisture content of 3%, powdered superphosphate is 7-8%. In order for the granulation process to proceed efficiently, the moisture in the feedstock must be uniform,

The introduction of the proposed method in the industry does not require significant technological changes and allows to increase the yield of marketable fraction of granular superphosphate 2-3 mm in size and the productivity of production lines.

Claims (3)

1. A method of granulating a simple superphosphate in the presence of a retur, followed by wetting, pelleting and drying the product, characterized in that, in order to increase the yield of marketable granules of 2-3 mm, the retur is divided into two fractions, one of which is 0-0, Before granulation, 5 mm is mixed with the mature starting superphosphate for 10-15 minutes, at which time the mixture is fed to the granulation with simultaneous introduction of a fraction of 0.5-1 mm in size, 2. A method according to claim 1, characterized in that the charge is moistened to a moisture content of 9-11%. 3. Method according to paragraphs. 1 and 2, characterized in that the pelleting of the superphosphate on the granules is carried out within 4-6 minutes ,Table 1 The effect of the granulometric composition of the retur on the output of the commodity fraction granulation go superphosphate Table 2 Effect of moisture content of the charge in the granulator on the output of the commodity fraction of granular superphosphate Table 3 Dependence of the yield of the commodity fraction of granular superphosphate on the time of the granule of table4 Dependence of the uniformity of wetting of the retur, (0.5 mm) of superphosphate on time