SU1208037A1 - Method of producing complex fertilizer - Google Patents

Description

The invention relates to the production of mineral fertilizers and relates to the preparation of concentrated complex fertilizers.

The purpose of the invention is to increase the fluidity of the melt and reduce the hygroscopicity of the obtained product.

Example 1. 100 g of potassium chloride are decomposed with a mixture of 82.32 g of polyphosphorous (76.7% PjO) and 46.15 g of 92.5% HjSO (the norm is 65% of the stoichiometric rate for decomposing potassium chloride) into glass in a reactor equipped with a stirrer, with a weight ratio of the starting components PjjOyrK O 1: 1 and temperature for 1 hour. The resulting (166.37 g) acidic decomposition product (melt) is cooled to 130 -; and neutralize 67.65 g of solid urea (the ratio of urea and acid decomposition products is 0.41-1) at A5-120 s for 20-30 minutes. The resulting complex fertilizer has a composition, wt -,%: N 13,75; P205oA.27.70; Pj0580A "27.70, Pr 5 5 or 75, P 205 half" | .23,0; , 27.70; . degree of conversion of polyform P, 05-83.03%; the amount of nutrients 69,15%, pH 6.2; hygroscopic point 70%; I: P205: K20 0.5: 1: 1.

Example2. 100 g of LIA chloride are decomposed with a mixture of 82.32 g of polyphosphorous (76.7%) and 46.15 g of 92.5% (normal H, 304b5% of the stoichiometric standard for decomposition of potassium chloride) in a glass reactor, equipped with a stirrer, at a weight ratio of 1: 1, a temperature of 250 ° C for 1 hour. The resulting PL (166.37 g) is cooled to 125-130 ° C and 135.30 g of solid urea is neutralized at 120 ° C for 25-30 minutes (at neutralization, the weight ratio of urea and acidic decomposition products is 0.81: 1). The resulting fertilizer has a composition, wt.%: N 21.75; , 85,. 21.85; PjO, ort 3.74; Pro, ,, 18,11; K., 0o, 21.82; degree of conversion of the polyform R., 90%, pH 6.4; the sum of nutritional components is 65.42%, hygroscopy of the point 72%; N:. 1: 1: 1.

PrimerZ, 100 g of potassium chloride is decomposed with a mixture of 54.90 g of polyphosphoric (76.6%) and 71 g

2080372

92.5% (standard stoichiometric) in a glass reactor equipped with a stirrer, with a weight ratio of .O 1: 1.1 and 5 at a temperature of 250 ° C for I h. The resulting (151.91 g) melt is cooled to 130-140 ° C and neutralized at 115-120 ° C 90, 21 g of solid urea (when neutralized, the ratio of urea

ten

and acidic decomposition products is 0.6: 1). The chemical composition of the obtained fertilizer is as follows, wt%: N 18.30; Pj050 418.45 ,.

. 5.96;

 5 Р, 0 «„ „.., 12.49, К, 0„ 27.66; steZ 5 POYM

Stump conversion polyform R., 70%; the amount of nutritional components 64.41%; pH 6.6; hygroscopic point 73%; Y: P205: K O 1: 1: 1.5,

20 In the proposed method of neutralizing urea, the acidic decomposition products of potassium chloride of polyphosphoric and sulfuric acids are subjected at 250 in a weight ratio

25 p20y: K20 1: 1; 111.5. The decomposition products consist of potassium acidic polyphosphates (КН2Р04, ,, КН, Р, 07. К ,, НРгО ,, К, Н, Р, 0, „, K, EjP, Of“, К ,,,,, ,, et al), Bisul30 fata kali -.KHSO double compound - KHjPO. KHSO, as well as free polyphosphoric and sulfuric acids, When neutralizing the excess acidity of acidic products of decomposition with urea, parallel reactions take place simultaneously between urea and individual ortho-pyropolypoly-, tetrapoly- and pentapolyphosphoric acids, with the formation of corresponding 40 urea polyphosphates. Acid potassium polyphosphates contain up to 12-15% of free polyphosphoric acid and up to 10-12% of free sulfuric acid. When neutralizing urea

45 in the presence of strong sulfuric acid is partially decomposed into COj and NHj. The leaked NH reacts with sulfuric acid to form ammonium sulfate. All these reactions proceed simultaneously and end within 25-30 minutes, and the process proceeds in a strong manner. smooth flowing,. .

B proposed process.

The formation of a free flowing melt depends on the chemical compositions of the acidic decomposition products, on the weight ratio of urea to acidic decomposition products, and the temperature during the neutralization stage.

When neutralizing the excess acidity of acidic decomposition products with urea, an unexpected phenomenon was discovered: at a temperature of 115-120 ° C, a high-flowing melt is formed, a homogeneous mass is obtained, and extremely favorable conditions are created for the intensive process of neutralization and granulation. The viscosity of the high-strength melt produced is at a temperature of (1 I 5O V.1

G; 120 C) neutralizing 40-50 cP, t, that is, the viscosity value equals the viscosity of some liquid fertilizers. The formation of sylleto-fluid melt greatly improves the uniform distribution of | Urea throughout the reaction | Mass, and the contact of urea with free acid molecules, as a result of which the neutralization process is intensified.

The process of formation of a high-flowing melt is significantly affected by the weight ratio of urea to acidic decomposition products. As a result of the experiments, it was revealed that it is precisely at the weight ratios of urea to the acidic decomposition products. In the limits of € A1-0.81: 1, a highly flowing, homogeneous melt is formed. The choice of the proposed weight ratio of urea to acidic decomposition products is not determined with the desired ratio of nutrients in the resulting fertilizer. This ratio is optimal, which forms the editor N. Kishtulinets

Order 173/32 Circulation 420 Subscription

VNISH1I USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Branch PPP Patent, Uzhgorod, st. Project, 4

with a homogeneous, flowing fluid, creating a favorable condition for a significant improvement in the technological effectiveness of the neutralization and granulation process. By reducing the ratio to less than 0.41: 1, the fraction of urea that goes to form a high-flowable melt decreases, resulting in no easily agitated melt and a neutralization and granulation condition. At a higher ratio, i.e. Higher than 0.81: 1, the miscibility of the starting components is impaired, does not form a mixed uniform surface, which in turn leads to a deterioration of the neutralization and granulation conditions, as well as the uniformity of the fertilizer obtained. In addition, the quality of the final product is improved (non-compacted, non-hygroscopic) and balanced nitrogen-phosphorus-potassium fertilizer is obtained. In the fertilizers obtained, the content of the hygroscopic substance (urea ortho-sulphate) is only 5-6%. The remaining 94-95% are non-hygroscopic compounds, such as CO {NH2.) 2. KHSO, КН304.КНгРО +, СО

0 (NH) z H4P., Oj, CO (1Shg) g. ,,, SOSMTS)., (1G4) G304. The hygroscopic point of these compounds varies on average between .70-; 80%. Therefore, the average hygroscopic point of fertilizer is in the range of 70-73%. Four-layer bituminized or plastic bags are not required for storage and transportation.

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Compiled by Gerasimov Tehred O. Vashchishina Corrector M. Pojo

Claims (1)

METHOD FOR PRODUCING COMPLEX FERTILIZER by decomposition of potassium chloride with a mixture of poifosforic and sulfuric acids at elevated temperature, neutralization of acidic decomposition products with a neutralizing additive, followed by granulation of the obtained melt, characterized in that, in order to increase the fluidity of the melt and reduce the hygroscopicity of the obtained product, use as a neutralizing additive urea with a mass ratio of urea and acid decomposition product of 0.41: 1-0.81-1 and a temperature of 115 ~ 120 ° C.