SU1505920A1 - Method of producing lime-ammonia fertilizer - Google Patents

Abstract

The invention relates to methods for producing granulated ammonium-ammonium fertilizer and allows increasing the strength of the granules, reducing nitrogen losses and product caking. The method includes mixing the lime component - lime, chalk, dolomite, cement dust, metallurgical slag, phosphogypsum and / or mixtures with melt of nitrate-containing salts, granulating, drying, cooling the finished product, while in the mixing stage the melt is fed in an amount of 1.0- 70% of its total mass, and the remaining amount of water is sent to the granulation stage. 1 hp ff, 1 tab.

Description

The invention relates to methods for producing granulated lime ammonium fertilizer (nitrate) used in agriculture.

The aim of the invention is to increase the strength of the granules, reduce nitrogen losses and fertilizer caking.

The method is carried out by mixing the lime component with the melt of nitrate-containing salts, followed by granulating, drying and cooling the product, while melting the nitrate-containing salts to the mixing stage is served in an amount of 1.0-70% of the total mass, and the rest of the water is granulated,

The lime component, chalk, dolomite, cement dust, metallurgical schlak, phosphogypsum and / or mixtures thereof are used as a lime component.

The essence of the method is as follows.

The melt of the nitrate-containing salt in the amount of 1-70% of its total mass is fed to the displacement with the lime component. The resulting solid mixture is sent to a granulator where the remaining part of the melt-nitrate-containing salt is sprayed. When this occurs, the application (spraying) of melt onto the surface of solid particles of the mixture, the pellets are pelleted with simultaneous sticking of fine particles of the mixture to their surface. As the granules advance in the granulator, they are cooled, accompanied by the crystallization of their liquid phase (deposited melt of nitrate-containing salts), hardening of the granules throughout the mass and dusting them with the lime-containing component of the mixture.

Hardening of the obtained granules occurs due to the occurrence of salt bridges in the entire volume of the granules resulting from crystallization (L

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reduction of caking and nitrogen loss occurs due to the practical elimination of the conversion reaction between lime and nitrate containing components, since the contact time of the lime component with the melt of nitrate containing salts due to rapid cooling and crystallization of the melt in the proposed method is negligible.

Characteristics of the obtained fertilizer are shown in the table.

It can be seen from the table that the introduction of 15 molten nitrate-containing additives in the first stage in an amount of 1-70% of the total mass of the melt allows to obtain a non-sticking product with a strength of 30-40 kgf / cm with relatively minimum x loss of nitrogen (0.1-0 , 3%). When carrying out the process according to a known method, the strength of the granules is 8-12 kg / cm, nitrogen loss 0.35-0.5% .25

When feeding the melt to the first stage in an amount less than 1 wt.%, Large lime lime dusting is observed, the granules of lime ammonium fertilizer have low strength, which leads to a large loss of m.

Introduction of melt to the mixing stage in an amount of more than 70 wt.% Leads to an increase in caking of the product due to the formation of a large amount of hygroscopic calcium nitrate and decomposition of ammonium carbonate formed, which leads to an increase in nitrogen losses.

Example 1. 16 g of ammonium nitrate-ammonium nitrate are fed to the mixing stage with 1000 g of limestone. The rest of the melt (1584 g) is fed to the granulation stage. Product

Example 2. A melt of ammonium nitrate in the amount of 550 g is fed for mixing with 1000 g of ground lime. At the granulation stage, the remainder of the melt (550 g) is added. The product is dried and cooled. The strength of granules is 35 kgf / cm, caking is 0.20 kgf / cm, nitrogen loss is 0.25%.

Example 3. Ammo nitrate melt in the amount of 1120 g is fed for crushing with 1000 g of dried phospho-gypsum. At the granulation stage, the remaining portion (480 g) of ammonium nitrate is added. The product is dried and cooled. The strength of the product is 40 kgf / cm, the caking is 0.25 kgf / cm. The loss of nitrogen is 0.30%.

Claims (3)

1. A method for producing lime-ammonium fertilizer, comprising mixing the lime component with the melt of nitrate-containing salts, granulating, drying, cooling the product, characterized in that in order to increase the strength of the granules, to reduce the nitrogen losses and the caking of the product, the melt of nitrate-containing salts is fed to the mixing stage in an amount of 1.0-70% of the total mass, while the remaining amount of the melt is directed to the granulation stage. 2. The method according to claim 1, about t l and h a - y y and with the fact that as dried and cooled. The granules of the obtained 45 lime component are used th fertilizer have a strength of 30kgs / cm limestone, chalk, dolomite, cement caking 0.1 kgf / cm, lost dust, metallurgical slag, phosphoazoto About 08%. gypsum and / or mixtures thereof. Example 2. A melt of ammonium nitrate in the amount of 550 g is fed for mixing with 1000 g of ground lime. At the granulation stage, the remainder of the melt (550 g) is added. The product is dried and cooled. The strength of granules is 35 kgf / cm, caking is 0.20 kgf / cm, nitrogen loss is 0.25%. Example 3. Phosphate of ammonium nitrate in the amount of 1120 g is fed for mixing with 1000 g of dried phospho-gypsum. At the granulation stage, the remaining portion (480 g) of ammonium nitrate is added. The product is dried and cooled. The strength of the product is 40 kgf / cm, the caking is 0.25 kgf / cm. The loss of nitrogen is 0.30%. The main technical advantages of the method are the possibility of obtaining non-caking strong granulated fertilizers with soil deoxidizing properties, reduced nitrogen loss, the use of heavy tonnage waste from other industries: cement dust, metallurgical slags, phosphogypsum, or mixtures thereof. Invention Formula 1. A method for producing lime-ammonium fertilizer, comprising mixing the lime component with the melt of nitrate-containing salts, granulating, drying, cooling the product, characterized in that in order to increase the strength of the granules, to reduce the nitrogen losses and the caking of the product, the melt of nitrate-containing salts is fed to the mixing stage in an amount of 1.0-70% of the total mass, while the remaining amount of the melt is directed to the granulation stage. 2. The method according to claim 1, about t l and h a - y y and with the fact that as 10 15 30 35 40 45 .50 0.05 0.08 0.10 0.20 0.30 0.40 ..