SU1661180A1 - Method of producing modified nitrogen fertilizer - Google Patents

Abstract

The invention relates to the technology of inorganic substances, in particular to the production of nitrogen fertilizers modified with nitrification inhibitors, and contributes to simplifying the process and reducing the content of toxic pyrazole, increasing the thermal stability of the product, as well as improving the physical and mechanical properties without reducing the degree of inhibition. According to the invention, lignin-containing natural polymers (lignin, agrimus) with a specific surface of 250 - 750 m ² / g and a dispersion of 50 - 250 µm are introduced into a solution or a melt of nitrogen fertilizers with a temperature of 90-130 ° C with a specific surface area of 2-2 10% ILC, in the amount of 0.5 - 1.0% in terms of the active substance. KMP is a melt of 1-carbamoyl-3 (5) methylpyrazole. The static strength of the granules increases 1.5-2 times and caking decreases 2.3-3.0 times. 1 tab.

Description

The invention relates to the production of mineral fertilizers and can be used to obtain nitrogen fertilizers with improved physicomechanical and agrochemical properties.

The purpose of the inventions is to simplify the process, reduce the content of the deficient pyrazole and increase the thermal stability of the product, as well as improve the physical and mechanical properties without reducing the degree of inhibition.

Example 1, 1.5 kg of a 65% carbamide solution in a drum granulator torus dryer with a temperature of 130 ° C, placed 25 g of a nitrification inhibitor containing 0.5 g of CMP (melt 1-carbamoyl-3 ( 5) -methylpyrazole) and

24.5 g of agrimus with a specific surface area of 250 m / g and a dispersion of 110 µm (0.5% ILC based on the amount of fertilizer). The inhibitor is evenly distributed in the urea solution and the solution is fed using a nozzle into a drum containing 0.5 kg of retour. The cooled granulated product with a granule diameter of 1-3 mm, a static granule strength of 1.2 kg / granule Jnpn dr 2 mm) and a caking rate of 0.15 kg / cm is used as a nitrification inhibitor. The rate of inhibition of nitrification of ammonium nitrogen is determined as follows.

In a 0.5 liter vessel, 500 g of air-dry soil are added to which 215 mg of urea (amide nitrogen 200 mg / kg of soil) and 2 mg of inhibitor are added.

ABOUT

about

00

about

(2% of carbamide nitrogen). The soil is moistened to 60% of full moisture capacity ™ and kept in a thermostat at 28-30 ° C with periodic control of the degree of inhibition of nitrification I by fomule

| 4-1 °°%

and with

where a is the content of nitrates and nitrites in a soil sample with carbamide prior to the addition of the inhibitor;

b - the content of nitrates and nitrites in the soil sample with urea and nitrification inhibitor.

c is the content of nitrates and nitrites in a soil sample without urea and a nitrification inhibitor.

Example 2. 100g of carbamide melt with a temperature of 130 ° C, which is melted in barely made of stainless steel with a body diameter of 60 mm and a height of 180 mm and equipped with a nozzle with a diameter of 1 mm at the bottom of the bottom, contains 10 g of the inhibitor containing 9 g of lignin with a specific surface of 750 m / g and a dispersion of 150 microns, modified with 1 g of CMP (1% of the active substance in terms of the amount of fertilizer). Granulation is carried out in a solution of an organic heat carrier (kerosene) to obtain spherical granules with a diameter of 1–4 mm, static strength of 0.15 kg / cm (with dr 2 mm). The results of the study of the degree of inhibition of nitrification are shown in the table. In examples 2-9 presented in the table, the determination of the degree of inhibition of nitrification as in Example 1. The data presented indicate that the use of natural polymers with a specific surface area of less than 50 m / g as an inhibitor does not provide the necessary reduction in the degree of inhibition of nitrification as a result of partial decomposition of CMP in solution or molten carbamide (examples 6 and 7)

Lignin-containing natural polymers with a specific surface area of more than 750 m / g cannot be obtained.

The use of natural polymers with a dispersity of more than 250 µm as inhibitors leads to an uneven distribution of the inhibitor in the granules and the blocking of granulators in the process of granular recooling. In addition, the physicomechanical properties of granules containing an inhibitor with a dispersity of more than 250 microns are close to those of a known fertilizer (Example 6),

The introduction of less than 0.5% CMP into a solution or melt of urea does not significantly reduce the degree of inhibition of nitrification (Example 4), and the introduction of more

1.0% - does not provide a noticeable advantage over samples containing 1.0% (example 5).

Carrying out the process at t 130 ° C leads to a decrease in the inhibitory activity (example 8), at t 90 ° C, the carbamide melt crystallizes, and the granules obtained in the BGS apparatus from solution have unsatisfactory physicomechanical properties (example 9 ).

Agrimus is a large-tonnage waste produced by furfural using calcium monophosphate as a catalyst. Agrimus has the following composition, 5 wt.%:

Dry substances (lignin and hardly hydrolysable polysaccharides) 25-35

Ash (CaO) 20-30

Free furfurol0,10 0,3

Phosphorus (in terms of

on Р205) 8.0-10.0

Moisture 20-30

pH2-4

5Hydrolysis lignin is a large-scale waste from the microbiological synthesis of feed protein. Lignin has the following composition, wt.%:

Dry substances (lignin itself and 0 residues of hardly dehydrolysable polysaccharides) 65-85 Ash (CaO, MgO, Si02) 2-10 Moisture 30-40 Formed in the synthesis of furfurol and feed protein, agrimus and lignin in the swollen state have an enormous specific surface (250-750 m / g), filled with moisture.

The implementation of the proposed method makes it possible to simplify the production of modified nitrogen fertilizers by combining the steps of introducing the inhibitor into the solution or melt of urea and granulation, to expand the scope of use of the inhibitor, using known methods for granulation — replenishment and granulation in HBF, not special designs of granulators that require development, reduce the content of deficient biologically active pyrazole in granules by 1.5–2 times without reducing the degree of inhibition, improve the main physicomechanical s properties of modified fertilizers (to increase the static strength of granules by 1.5–2 times and reduce caking by 2.3–3.0 times in comparison with the known method).

Claims (1)

The lignin-containing compounds introduced together with the fertilizers contribute to the improvement of the soil - an increase in the content of humic substances in it. Claims A method for producing modified nitrogenous fertilizer, which includes treating carbamide with a nitrification inhibitor, based on 1-carbamoyl-3 (5) methylpyrazole and granulating the product, in order to simplify the process of reducing the toxic pyrazole content, increasing the thermal stability of the product, 0 as well as improving the physicomechanical properties without reducing the degree of inhibition, as a nitrification inhibitor, use agrimus or lignin in the swollen state with a specific surface of 250–750 m / g and a dispersion of 50–250 µm, previously modified by 2–10% 1-carbamoyl-3 (5) -methyl pyrazole, and the treatment is carried out by introducing an inhibitor in the amount of 0.5-1.0% in a solution or melt of urea at 90-130 C.