SU1118625A1 - Method of obtaining phosphorous fertilizer - Google Patents

Abstract

A method of producing phosphorus fertilizer, including the decomposition of phosphorite flour with phosphoric acid, granulation and drying of the pulp in the presence of a retur, characterized in that, in order to increase the productivity of drying equipment by reducing the amount of evaporated water and the returum number while maintaining the quality of the product, the phosphorus flour with tint grinding, corresponding to a residue on a sieve of 0.18 mm, amounting to 6-30%, and 30-100% of phosphate rock is decomposed simultaneously with granulation and drying. (L

Description

00 od 1C

The invention relates to a technology of mineral fertilizers, namely to the production of phosphate fertilizer with program dissolution. In phosphate fertilizer with programmed dissolution (activated pho- phorite, superphos), the PjOj part is found in a rapidly absorbable (water-soluble) form. The remaining amount of P is in an activated, slow digestible form. The fast-digesting form of PfO is consumed by the plant at the beginning of the growing season, the slow-growing form P Oj is consumed from the middle, the end of the growing season, and also in the subsequent years after application. A known method for producing phosphorus fertilizer, concludes that phosphorite that has undergone anionic flotation is subjected to activation with sulfuric acid, cationic flotation, and activation with phosphoric acid. In the final product Р Р, 13. The disadvantage of this method is the presence of two stages of flrtation and two stages of activation, which complicates the technological scheme. The closest to the proposed technical essence and the achievable result is the method of obtaining phosphate fertilizer, which consists in the decomposition of all phosphate phosphate (phosphate rock) phosphoric acid. Then the pulp is sent for granulation and drying in the presence of Retur 2, However, this method is characterized by a large amount of evaporated water. When using concentrated phosphoric acid containing 50% PjOj, it must be pre-diluted with water or absorption solutions to a content of 24-28% PjOg- Then this water (61 kg per 100 kg of phosphate raw material) is removed when the product is dried, which is coupled with large energy costs. In addition, a large retreat number of the process (the ratio of the mass of the retour at the granulation stage — drying to the mass of the product being dried) equal to 2.0, leads to a decrease in the productivity of the drying equipment. The aim of the invention is to increase the productivity of the drying equipment by reducing the amount of evaporated water and the return number while maintaining the quality of the product. The goal is achieved by the fact that according to the method of obtaining phosphate fertilizer, including the decomposition of phosphate rock with phosphoric acid, granulation and drying of the pulp in the presence of retur, the phosphate rock is taken by fine grinding, corresponding to a residue on a 0.18 mm sieve, 6-30%, and 30-100% of the phosphate rock is decomposed simultaneously with the granulation and drying. The differences of the proposed method are: 1. The use of phosphate phosphate flour of fine grinding, corresponding to the residue on the sieve with a cell size of 0.18 mm, amounting to 6-30%; 2. The phosphate flour is decomposed simultaneously with granulation and drying. At the same time, the phosphate flour is fed directly to the granulation-drying stage (to the drum granulator torus dryer), where it is activated under conditions of elevated temperatures and acid concentration. 3. The amount of fosmuk supplied to the granulation - drying, equal to EO-100% of the total. Example 1. 70 kg of phosphate flour (28% P20j) with a residue on a sieve of 0.18 mm, which is 6%, process in a mixer 100 kg of phosphoric acid (30% PjOj) obtained by diluting 60 kg of phosphoric acid (50%) AB kg of water. The resulting pulp (4) is fed to the drying and granulation in the apparatus BGS. 30 kg of phosphate rock (30% of the total amount) are fed directly to the granulation and drying stage in an HGS apparatus. The process is carried out at the gas temperature at the inlet to the BGS 500-550C, at the outlet 90-11. The resulting product contains 38% P20.G06Ts 20% PgO ,. Pellets with a size of 1-3 mm are 90%. In this case, it is necessary to evaporate 46 kg of water; the return value is 1.5. Example 2. 34 kg of phosphate rock (28% PjOj) with a residue on a sieve, 18 mm, amounting to 20%, are treated in a mixer with 78 kg of phosphoric acid (38% PjPg) obtained by diluting 60 kg of phosphoric acid

3

(50% P 0 ") 18 kg of water. The resulting pulp (T / L 1 / 2.2) is fed to the drying and granulation apparatus BGS. 66 kg of phosphate rock (66% of the total amount) is fed directly to the granulation and drying stage in an HGS apparatus. The process is carried out at a temperature gaEov at the entrance to the BGS ZOO-ZZO C, at the exit 90-1

The resulting product contains 38%; 25% P, 0 and 20% P, (X5v, d. Granules with a size of 1-3 mm are 90%. In this case, .24 kg of water must be evaporated, the return value is 0.4.

Example 3. All phosphate phosphate 100 kg of phosphate flour (28% FjOj) with a residue tamper 0,18 mm, constituting 30%, is served directly to the granulation stage and the head (in the BGS apparatus). 73 kg of phosphoric acid (41%

254

FjOj) obtained by diluting 60 kg of phosphoric acid (50% PjOy) with 13 kg of water. The process is carried out at a temperature of gases at the inlet to the BGS for 500-550 s, at the outlet 90-110 s.

The resulting product contains 38% PzOjaS; 26% P. and 20% P, 0, Granules with a size of 1 h3 mm are 90%. It is necessary to evaporate

19 1sg water. The return value is 0.3.

In tab. 1 compares the main characteristics of the process within the limits (examples 1–3), characterizing the process carried out with the feed of the fusmoux granulation stage — drying in an amount less than 30% (examples 4 and 5), using the fosmouc with the residue on the sieve

0.18 mm less than 10% and more than 30% (examples 6 and 7) and the characteristics of the process carried out on the prototype (example 8).

D a b l and c a 1

66

100

20

ten

thirty

thirty

ABOUT

30 30 30 30 30 30 30

20 30

6

6

3

40 13.

Example No.

1 2 3 4 5 6 7 8 From the table. 1, it can be seen that the management of the process s with the required limits of the parameters reduces the amount of evaporated water by 3 g 3.2, and the return number by 1.7 - 12.5 times. The supply of fosmuki to the drying granulation stage in an amount of less than 30% (examples 4 and 5) increases the amount of evaporated water to 51 kg (increasing the load on the drying equipment). When this results in a too thick slush of inactive pulp (as in the prototype, the ratio T / W approaches 1), the retractable number increases, the productivity of the drying equipment decreases. When using fosmuki more fine grinding with a residue on a sieve of 0.18 mm, equal to 3% (example 6), the return value increases. In addition, in this case, the possibility of fosmuk entrainment from the HGS apparatus increases, together with the exhaust gases. When using fomuki more coarse grinding - the residue on a sieve of 0.18 mm 40% (example 7) does not fully decompose phosphate, which leads to a decrease in the content of PjOyeoA in the product. Fertilizers are characterized by the following agrochemical indicators,%: Sample 1 P, 0'5 39.8; 21.3 РгО eoAnb.v; Sample 2 P, 26.6 P20v "u" 2 5. The efficiency and digestibility of phosphorus were studied by the fertilizer researcher when they were mainly applied to crops on two soils (sod-podzolic, DAOS loamy clay, 1/2 of hydrolytic acidity and black soil ). In experiments with barley, new fertilizers (granule size 1-3 mm) were studied in comparison with double superphosphate. In experiments with durum wheat, the effect of granule size (1-2, 2-3, and 3-4 mm) on fertilizer efficiency was tested. The results of vegetation experiments with barley (the effectiveness of fertilizers with an adjustable dissolution rate, obtained on the basis of the Kingisepp phosphate in LenNIIP1prohim) are given in Table. 2

md i g

0.8

0.6 In order to increase the effectiveness of fertilizers in the ratio of 1: 1.

The results of vegetation experiments with dough wheat (the effect of granule size on the effectiveness of fertilizers with adjustable co-NK-background19, 6 12.9 34.0 13.6 Sample 132.7 12.0 32.3 11.8 Sample 231.8 10, 0 YK-fnn26.1 13.9 36.4 14.3 Sample 135.6 14.5 37.0 14.6 Sample 236.2

table 2

0.5

0.5

Table 2 shows that the solutions obtained on the basis of Kingisepp phosphate in LenNIIShprokhim are given in Table. 3

Table 3

Sod-podzolic soil

11.2 11.4 Che

11.5 13.4 the soil is diluted with sand 30.812.929.4 31.611.329.8, with the soils 34.013.330.2 35.113.634.6

The average of the options with granules 1-4 mm

Options

MK-von Sample Sample

NK-background Sample Sample On the basis of preliminary data of agrochemical tests, it can be concluded that new forms of phosphate fertilizers with a particle size of 1-3 mm are not inferior in their

Continuation of table 3

Sod-podzolic efficiency and phosphorus digestibility of double superphosphate. The increase in the size of the granules of sample 1 to 3-4 mm was accompanied by a decrease in its fertilizing value.

Claims (1)

) METHOD FOR PRODUCING PHOSPHORUS FERTILIZER, including decomposition of phosphoric flour with phosphoric acid, granulation and drying of pulp in the presence of retur, characterized in that, in order to increase the productivity of drying equipment by reducing the amount of evaporated water and reture number while maintaining the quality of the product, phosphorite flour is taken with fineness grinding corresponding to the residue on the sieve of 0.18 mm, comprising 6-30%, and 30-100% of phosphate rock decompose simultaneously with granulation and drying.