SU1249004A1 - Method of producing suspended fertilizers - Google Patents

Description

This invention relates to methods for producing mineral suspended nitrogen-phosphate fertilizers.

The purpose of the invention is to simplify the process by eliminating the addition of the suspending agent and increasing the nutrient content.

The proposed method is carried out as follows.

Water is added in the amount of 2.8-14.8% and urea in the amount of 10-40% to the ammonium polysphosphate solution with stirring, the amount of water being chosen from the following relation

C.0, 2, where C is the amount of water,%;

C is the amount of urea,% (examples 2, 3, 4).

Since the dissolution of urea in the aiiiMOHHH polyphosphate solution is accompanied by an endothermic effect, in the case of a high urea content, it is advisable to heat the suspension to room temperature to speed up the process of suspension and penis.

The amount of carbamide is limited below the crystallization region of carbamide (example 1). An increase in the content of urea more than 40% is inefficient due to the sharp decrease in its solubility and, as a result, the content of solid phase and high viscosity of suspensions (example

The introduction of water regulates the density of the saturated phase of the suspensions. The introduction of a smaller amount of water leads to an increase in the viscosity of the suspensions and to their thickening, while an increase in the amount of water leads to a decrease in the concentration of nutrients, as well as to a decrease in the density of the suspension phase below the density of urea and it precipitates to the bottom (example 6 and 7).

A variant of the method of obtaining suspensions was the use of ammonium nitrate together with urea, which expands the raw material base of nitrogen-containing compounds and meets the requirements of agriculture for nitrogen-phosphorus fertilizers, which in some cases must contain all three forms of nitrogen — ammonia. , nitrate and amide.

The use of ammonium nitrate causes a more dramatic change in the density of the liquid phase of the suspension, and this.

in turn, it changes the concentration limits of the components of the suspension, providing stable fertilizer. First, the change

limits on carbamide concentration (10-33%); secondly, the dependence that determines the amount of water introduced is changed:, 44 (C) (+ Cd) -4.6, where Cj, Sc, GC, water amount,

carbamide and ammonium nitrate, respectively,%. Thirdly, the use of ammonium nitrate is limited by its relationship with carbamwood in relation to the possibility of nitrate crystallization.

ammonium, whose density is lower than the density of the liquid phase, therefore the ratio should be 1: 1-4: 1. A decrease of this ratio below 1: 1 causes crystallization

(Example 11), and an increase of more than 4: 1 increases the solids content in the suspension and, accordingly, its viscosity. With this in mind, the limiting amounts of amselitra are 5–17%,

and water - 2-17.4%.

The method without the use of ammonium nitrate pains is simple in hardware design.

Examples of the implementation of the variants of the method are given in the table.

A suspension based on a solution of ammonium carbamide polyphosphate and water was prepared as follows (Example 3) ..

In the tank, equipped with a mixer, with a capacity of 8-10 m wash down the ammonium polyphosphate solution in the amount of

8020 kg and water in the amount of 480 kg. With stirring, carbamide is added in an amount of 1500 kg. After stirring for 15-20 minutes, the suspension is ready for use.

The composition of the suspension,%: nitrogen, 14.9, 27.3. After storage for a week, the viscosity of the suspension remains almost unchanged.

A suspension based on a solution of ammonium polyphosphate, carbamide, ammonium nitrate and water was prepared as follows (Example 9).

Ammonium polyphosphate solution in the amount of 5420 kg and water in the amount of 1080 kg are poured into the tank with a mixer with a capacity of 8-10 m. While mixing, 2800 kg of urea are introduced into the tank and

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700 kg of ammonium nitrate. After per.e-Composition,%: nitrogen 20.7, P, Oj- 18.4.

During the period of 15–20 min, the suspension viscosity of the suspension is about 80 centipoise and not ready. varies during storage.

Claims (2)

1. METHOD FOR PRODUCING SUSPENDED FERTILIZERS by mixing phosphorus and nitrogen compounds and water at room temperature, revealing that, in order to simplify the process by eliminating the addition of a suspending agent, increasing the nutrient content, the solution of ammonium polyphosphates is mixed with carbamide in an amount of 10- 40% and water in an amount determined from the dependence С _В = О, 4'С _К - 1,2 where С J - amount of water,%; With _to - the amount of urea,%. 2. The method according to π. 1, with the fact that, in order to increase the efficiency of fertilizer, urea in the amount of 10-33% is additionally mixed with ammonium nitrate in the ratio urea: ammonium nitrate 4: 1 - 1: 1, and the amount of water is determined from addictions C ₆ = 0.44 (C _k + C _a ) -4.6 where C _# is the amount of water,% j C _k is the amount of urea,%; With _p-the amount of ammonium nitrate,%. SU ,, 1249004 1 12