SU1518327A1 - Method of producing granulated fertilizer - Google Patents

Abstract

The invention relates to a method for producing granular complex fertilizers, can be used to obtain fertilizers based on metallurgical slags, and contributes to reducing the consumption and concentration of moisturizing solutions, increasing the strength of granules, increasing the rate of their destruction in soil solutions and increasing the degree of P ₂ O ₅ digestibility. According to the invention, the crushed metallurgical slag is moistened with a solution containing potassium, magnesium and ammonium chlorides in the following ratio of components, g / l: MGCL ₂ 50-100

HCI 50-100

NH ₄ CL 1-5. Moistening with this solution is carried out at a ratio of T: W (8-12): 100 for 5-10 minutes. The proposed method allows reducing the salt concentration by 340 g / l and the consumption of moisturizing solutions by 12-28%, increasing the strength of the granules by 2-6 kgf / cm ² , the rate of destruction of the granules in 2% citric acid solution by 0.5 -0.7h and the degree of P ₂ O ₅ digestibility by 1.0-1.8%. 1 hp f-ly, 2 tab.

Description

one

(21) 4404563 / 31-26

(22) 04.02.88

(46) 10/30/89. Bnsh. No. 40

(71) Institute of Chemical Sciences

The Academy of Sciences of the Kazakh SSR, the Institute of Metallurgy and Enrichment, the Academy of Sciences of the Kazakh SSR, the Ural Scientific Research Institute of Ferrous Metals and the Karaganda Metallurgical Plant

(72) D.Zo Serazetdinov, A.V. Kirpichnikov, V.M. Gorbachev, 10.V. Sorokin, B, A. Mirko, A.N. Klimushkin, I.M. Shamardin and I.N. P | erbakov

(53) 631.893.26 (088.8)

(56) Patent GZH No. 0154482, cl. From 05 To 5/00, 1982.

(54) METHOD FOR OBTAINING GRANULAR FERTILIZER

(57) The invention relates to a method for producing granular complex fertilizers, which can be used to obtain fertilizers based on

metallurgical slags and contributes to reducing the consumption and concentration of moistening solutions, increasing the strength of granules, increasing the rate of their destruction in soil solutions and increasing the degree of digestibility. According to the invention, the crushed metallurgical slag is moistened with a solution containing potassium, magnesium and ammonium chlorides in the following ratio of components, g / l: MgCl 50-100; HC1 50-100; 1-5. Moistening with this solution is carried out at a ratio of T: W (8-12): 100 for 5-10 minutes. The proposed method makes it possible to reduce the salt concentration by 340 g / l and the consumption of wetting solutions by 12-28%, increase the strength of the granules by 2-6 kgf / cm, the rate of destruction of the granules in 2% citric acid solution by 0.5- 0.7 h and the degree of digestibility by 1.0-1.8%, 1 Cp f-ly, 2 tab.

from 3

(L

The invention relates to a method for producing granular complex fertilizers and can be used to obtain fertilizer based on metallurgical sacks.

The aim of the invention is to reduce the consumption and concentration of moistening solutions, to increase the strength of the granules, to increase the speed of their destruction in soil solutions, and to increase the degree of PjO digestibility,

The proposed method is illustrated by the following examples.

Example 1. Granulated mineral fertilizer is obtained from crushed to fraction O, 1 mm of converter slag of the Karaganda Metallurgical Plant, containing, in May.%:

ate

00 WITH

to

Cao

SiO-z

Plos

Regoz

MPO

MgO

NgO

33-42

12.5-15.5

8.3-8.9

23-27

3.4-5.2

6.5-8.7

Rest

The crushed converter slag of this composition enters the 2-screw mixer and is moistened for 7 minutes with a solution containing g / l KC1 50, MgCli 100, NH4C1 3, at a ratio W: T 10: 100, and then fed to a dish granule torus (diameter of the relay is 1.5 m, height of the bead is 15 mm, the angle of inclination of the plate is 46-48 °, the speed of rotation of the plate is 22-25 rpm). The obtained pellets fraction (1-a mm) is subjected to drying. The content of salts K, Mg, NH in the finished product is 1.5%. The finished product contains 93.8% in an assimilable form. The mechanical strength of the granules is 16 kgf / cm. The time of complete destruction of the fraction (1-4 mm) of the granules in a 2% citric acid solution is 3.5 hours.

The remaining examples are summarized in table 1.

The limits of the basic parameters are justified as follows. With an increase in processing time of more than 10 minutes, lime slaking and the formation of calcium compounds occur in the mixer, which leads to the formation in the volume of granules of compounds like hydroxyapatite. This hampers the destruction of the granules by soil solutions and the transfer of phosphorus to the soil.

When using moisturizing solutions containing less than 100 g / l of salt, the thickness of the crystalline hydrate layer does not provide sufficient strength of the granules, and when containing moisturizing solutions of more than 205 g / l of salt, the formation of crystalline hydrate occurs throughout the granule volume, which leads to a decrease in the rate of destruction granules soil solutions.

When the ammonium salt concentration in the wet solution is below 1 g / l, the efficiency of the decomposition process of calcium hydroxide decreases, resulting in a decrease in the content of digestible forms J and the rate of destruction of the granules. At concentrations of ammonium salt more than 5 g / l, the decomposition of calcium hydroxide occurs with a significant increase in ammonia, which loosens the granule and thereby leads to a decrease in its mechanical strength.

When the ratio W: T is below 8: 100, the pelletizing of the charge does not occur, and when the ratio W: T is more than 12: 100, the processes of lime slaking and the formation of hydroxyapatite in the volume

0

five

0

five

0

five

0

0

s

five

Pellets, which reduces the rate of destruction of pellets in the soil. In addition, with this ratio W: T, partial bleeding of the charge is observed, which impairs its transport properties and leads to clogging of the process equipment.

In tab. Figure 2 presents data confirming the need for selected Intervals (exorbitant values).

As can be seen from the above examples, when the slag treatment time is less than 5 minutes (Example 7), the ratio W: T 7: 100 does not completely granulate (50-60%), with a ratio of 13: 100, the mixture is not uniformly moistened, which leads to to uneven strength of the material (example 8), With a processing time of more than 10 minutes and a ratio of W: T 7: 100, insufficient contact leads to an increase in the amount of fines (0.5 mm), which reduces the productivity of the process, with a ratio of W: T 13: 100, the overwetting of the charge occurs, which leads to an increase in the fraction (+ 4.0 ta). In addition, the strength of the granules increases, which affects the decrease in the rate of dissolution of the granules by soil solutions.

Claims (2)

The proposed method, when the concentration of salts B of moisturizing solutions (101-205 g / l), the ratio W: 1 (8-12):: 100, and the treatment time of the crushed 5-10 NWH shpak, reduces the concentration of salts in comparison with the prototype method by 340 g / l and the consumption of wetting 1x solutions by 12-28%, increase the strength of granules by 2-6 kgf / cm, the rate of destruction of granules in 2% citric acid solution by 0.5-0.7 h and the degree digestibility by 1.0-1.8%. Claim 1. A method of producing a granulated fertilizer, including treating a crushed metallurgical ass with moisturizing solution containing potassium and magnesium chlorides, granulation and drying, characterized in that in order to reduce the consumption and concentration of moisturizing solutions, increase the strength of granules, increase the rate of their destruction in soil solutions and an increase in the degree of digestibility, the moistening solutions are complementary) 1o contain chloride ammonium in the following ratio of components, g / l: chloride Ratio W: T 8: 100 10: 100 Content in solution, g / l: KC17550 MgClj75100 NH Cl53 MgSO NaCl Durability of granules, kgf / cm 14,016.0 Time of granule destruction in 2% citric solution acid3,73,5 Solubility in 2% citric acid solution93,093,8 12: 100 7: 10014: 100 20: 100 10040 50110 10.5 12.5 3.8 8.0 3.8 BY 40 6 10.0 ,one 30,400 30 50 10.0 4.2 93,592,592,191,9 Note, Examples 4-5 - beyond, 6 - a prototype. Chloride ammonium 1-5 2. The method according to p. 1, otlicha12: 100 7: 10014: 100 20: 100 0040 50110 10.5 12.5 8.0 BY 40 6 10.0 30,400 30 50 10.0 3.8 3.8 ,one 4.2 table 2 Granule strength Time of destruction granules in 2% lemon solution acids Solubility P, 05 in 2% solution citric acid Continuation of table 2 4-12 5-6 18-20 4.0 3.8 5 hours 90.0 92.0 85%