SU1536354A1 - Method of obtaining granulated zinc-containing superphosphate - Google Patents

Abstract

This invention relates to a technology for the production of mineral fertilizers and relates to the production of granular zinc-containing superphosphate. The purpose of the invention is to preserve the strength of the granules during long-term storage and to reduce the yield of the fraction with a granule size of less than 1 mm. The method includes moistening the superformed powder with zinc-containing waste solutions for the production of purine preparations, containing 12–16% zinc sulfate and 6–10% organic substances, with a ratio of superphosphate and zinc-containing solution 10: (0.4–0.8), granulating and drying the obtained granules . 1 hp f-ly, 2 tab.

Description

The invention relates to a technology for the production of mineral fertilizers and can be applied to obtain granular superphosphate.

The purpose of the invention is to preserve the strength of the granules during long-term storage and to reduce the yield of the fraction with a granule size of less than 1 mm.

Example 1. Into a drum granulator serves, pre-neutralized to free phosphoric acid 2.0-2.4%, powdered superphosphate. Then, zinc-containing aqueous solutions, purine production wastes containing 12–16% zinc sulfate, 6–10% organic substances, at the rate of 4 parts by weight, are injected into the granulator using a pneumatic former. to 100 weight. including superphosphate. At the same time, superphosphate is rolled onto the granules. Then the obtained granules are dried, classified and cooled by blowing air.

The finished product has the following physico-chemical and mechanical indicators, wt.%: P205c8of 2,3; Pr05 SC8 20.4; moisture 2.8; granules with a size of 1-4 mm 92; -} mm 3; 4-6 mm 5; 6 mm O, the strength of the granules is 26 kgf / cm2 and after six months is maintained.

Example 2. The experimental procedure is similar to Example 1, but the ratio of superphosphate to zinc-containing waste is 10: 0.6.

The resulting product contains,%: P70yc8o (f 2.2; P705VcB20.2; moisture 2.7; granules with a size of 1-4 mm 94; Ј 1 mm 2; 4-6 mm 4; 6 mm 0; strength of granules 28 kgf / cm7.

Example 3. Experiments were carried out analogously to example 1, but comp.

with s &

00

ate

Ј

The effect of superphosphate on zinc-containing bypasses is 10: 0.8.

Contains in the finished product,%:

Ptt ° 5cwr2, l; P2OjVc6 20 2; moisture granules with a size of 1-4 mm 95; 1 mm 1;

 mm 4; 6 mm 0; granule strength 30 kgf / cm2.

The feasibility of the selected ratios and their effect on reducing the number of particles less than 1 mm in the product as well as maintaining the strength of the granules during long-term storage are given in table. 1, the degree of uniform distribution of zinc throughout the fertilizer mass increases the binding effect,

shown in Table. 2

From the above examples and Tables 1 and 2, it can be seen that the proposed method allows maintaining the strength of JQ granules during long-term storage (up to 6 months), reducing the number of fractions less than 1 mm in size (up to 1-3%) and increasing the degree of uniform zinc distribution do the whole mass of fertilizers (up to $ 1-96%). 25

In this case, it is advisable to maintain the ratio of Superphosphate and zinc-containing waste within 10: (0.4-0.8) By weight, since a decrease in these ratios leads to an increase in the fraction less than 1 mm in size, therefore, a decrease in strength 14ranul, and the increase does not give the desired effect. This is due to the fact that when a smaller supply (less than 0.4) of zinc-containing waste is reduced, the bond between the superphosphate particles and, consequently, the cohesive force, the granules are not sufficiently compacted when it is coated.

With an increase in the supply of zinc-containing waste, the granules turn out to be jjee large and doughy and smear on the surface of the equipment, and complicate the process of crushing the granules.

The granulation process in this method is carried out by mixing superphosphate particles with a zinc-containing additive, which allows preserving the strength of the granules during storage and ensures an even distribution of zinc throughout the fertilizer.

According to a known method of zinc-coke, the additive is introduced with a retur; when the superphosphate is rounded, it goes on

40

45

50

increasing the contact of superphosphate particles. Electron microscopic studies have shown that the solution used causes the formation of large friends of zinc phosphate crystals up to 50 microns in size and smaller crystals up to 10 microns, which fill the space between the large crystals, forming a monolithic surface.

The use of the proposed method allows reducing the fraction yield with a granule size of less than 1 mm and maintaining the strength of the product granules during long-term storage.

Claims (2)

1. A method of obtaining granulated zinc-containing superphosphate by moistening powdered superphosphate, granulating and drying the obtained granules, characterized in that, in order to preserve the strength of the granules during long-term storage and reduce the yield of the fraction with a granule size less than 1 mm in the product, as a moisturizing liquid They use zinc-containing waste solutions for the production of purine preparations with their ratio to superphosphate equal to 0.4-0.8: 10. 2. Method pop.1, characterized in that the zinc-containing spent solutions for the production of purine preparations contain, in May.% Zinc Sulphate12-16 Organic substances6-10 WaterEverything Zinc oxide on the surface of the recur (non-uniform one) and during storage of the fertilizer gradually the adhesion strength is destroyed and leads to a decrease in the strength of the granules. The zinc-containing waste solution for the production of purine preparations contains 12-16% zinc sulfate, 6-10% organic matter, the rest water. The solution used has a pH of 5.4-6.7 and contains organic complex zinc compounds Zn40 (CH3COO) s Zn2 (P04) 7 (OH), which .. five 0 five 0 increasing the contact of superphosphate particles. Electron microscopic studies have shown that the solution used causes the formation of large friends of zinc phosphate crystals of up to 50 microns in size and smaller crystals up to 10 microns, which fill the space between the large crystals, forming a monolithic surface. The use of the proposed method allows to reduce the yield of the fraction with a granule size of less than 1 mm and to maintain the strength of the product granules during long-term storage. Invention Formula 1. A method of obtaining granulated zinc-containing superphosphate by moistening powdered superphosphate, granulating and drying the obtained granules, characterized in that, in order to preserve the strength of the granules during long-term storage and reduce the yield of the fraction with a granule size less than I mm in the product, There are zinc-containing waste solutions for the production of purine preparations with their ratio to superphosphate equal to 0.4-0.8: 10. 2. Method pop.1, characterized in that the zinc-containing spent solutions for the production of purine preparations contain, in May.%: Zinc Sulphate12-16 Organic substances6-10 WaterEverything Table 1 With a retur at the superphosphate mixing stage (known) Without retour in the process of superphosphate wetting (proposed) table 2 1: (1.75-2.5) 76-82 10: (0.4-0.8) 91-96