CS235884B1 - Method of principal stabilized np-suspension preparation - Google Patents

Abstract

The purpose of the invention was to prepare highly a concentrated NP suspension containing sulfur % to 5 wt. This goal will be achieved ammoniacalization of a mixture of amophos and sulphate ammonium to pH 6.5 to 7. After ammoniacalization the reaction mixture is cooled and stabilized bentonite dispersion preparation.

Description

The invention relates to a process for preparing a basic stabilized NP suspension.

Sulfur deficiency in industrialized countries with a developed industry of combined NP and NPK fertilizers based on extractive phosphoric acid is eliminated by the use of liquid and suspension fertilizers, which are a good carrier medium for incorporating this macro-nutrient.

The need for fertilizer sulfur in some agricultural areas of the Czechoslovak Socialist Republic is covered by technical crystalline ammonium sulphate falling from coking plants, caprolactam production plants and in the production of ferric pigments. The disadvantage of this solid nitrogen fertilizer is, in addition to the low nutrient content (19.0 to 19.5% N, 22 to 24% S), considerable caking, due to an unbalanced granulometric composition (a significant proportion of dust content), causing difficulties in application spreaders.

Ammonium sulphate is a component of liquid and suspension N fertilizers and liquid NP fertilizers. Liquid fertilizer plants produce next door

235 884

N solutions of urea and ammonium nitrate hoses as well as a basic nitrogen solution with a sulfur content of 20.55 -0-0-5.8 S with a composition of * 23.75% by weight. % ammonium sulfate, 25.7 wt. % urea and 0.95 wt. ammonium nitrate. The advantage of this clear, liquid nitrogen fertilizer is its good cryoscopic properties - crystallization temperature - -21 ° C. The disadvantage is low concentration of nitrogen - 20.55% by weight, caused by low solubility of ammonium sulphate in solution of urea and ammonium nitrate. A further disadvantage of this liquid fertilizer is the limited miscibility with the basic NP solutions based on ortho and ammonium polyphosphates 8-24-0 and 10-34-0 in the preparation of NP mixed aNPK liquid clear fertilizers.

The low nutrient content is removed by introducing an N suspension based on urea and ammonium sulfate.

29-0-0-5 S, stabilized 1.5 wt. gel-forming clay

This suspension was prepared by ammoniacalization of concentrated sulfuric acid solutions (93 wt% H 2 SO 4) while diluting the reaction mixture with urea solution and an additional amount of water to cover the evaporation of the boiling water. The hot solution was cooled rapidly from 116 ° C to 38 ° C over 10 minutes in order to eliminate fine ammonium sulfate crystals by disturbed crystallization. Powdered attapulgite clay was added to the cooled N slurry to suppress nucleation and crystallization and sedimentation of the precipitated crystals. This procedure is described in US publications: Production of urea-ammonium sulfate suspension, 12 Demonstration, October 18-19, 1978, New Developments in Pertilizer Technology, TVA, National Pertilizer Development Center, Muscle Shoals Alabama, USA, 61-63, 1978.

In MS. No. 204,790 describes a process for the preparation of a stabilized N suspension having a content of 25 to 25

235 884 wt. % nitrogen and 0.5 to 5 wt. open. A reaction mixture is prepared from granulated urea, solution or solid ammonium sulfate and optionally water at 70-90 ° C, which is stabilized at a temperature below 60 ° C by addition of a natrified bentonite dispersion so that the product contains 30 to 20 ° after cooling. C 1 to 2 wt. bentonite.

DC Young protects, in U.S. Patent No. 3,046,105 (1962), a process for preparing NP ammonium sulfate solution type fertilizers. The preparation of this NP of liquid fertilizer consists in neutralizing pure phosphoric acid (54 wt% PgO 4) and industrial sulfuric acid (96 wt% HgSO 4), diluted with the calculated amount of water, ammonia gas or ammonia water. At the same time, the reaction mixture is cooled by means of a coil coil or recycled to the finished product through a coil with the cooling system extended. The neutralization is conducted so that the temperature of the reaction mixture is less than 93.3 ° C due to ammonia losses. Phosphoric acid is neutralized to the neutralization stage characterized by the compound (NH4) ^ 7 ^ 13 PO ^, representing the optimal solubility of the two components - (NH4 ^ γ PO ^ and (Nil ^) ₂ ) _.

SO ^ · Based on the mixture of H ^POig and IgigSO ^, NP-type fertilizers with a crystallization temperature of less than 0 ° C and the following tabulated composition can be prepared:

Type NP roz- flow Composition NP fertilizer (NH ^) ^ γΗ ^ ^ PO ^ ^ ^H 4 ^ 2 ^S ° 4 Content ingredients . % wt. N-PgO ^ -KgO-S · % wt. % wt. % wt. % wt 1. 5-10-0-2 S 17.9 8.3. 73.8 26.2 2. 8- 9-0-6,5 14.3 24.8 60.9 39.1 3. 9-22-0-2 S 39.4 8.3 52.3 47.7 4. 9-11-0-6 S 19.7 24.8 55.5 44.5

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The disadvantage of the process is the relatively low concentration of nutrients (15 - 31% by weight ·) and the need to use pure or purified acids, ie sulfuric and phosphoric acids.

A process for preparing a basic stabilized NP suspension containing up to 5 wt. Sulfur according to the present invention, characterized in that the aqueous suspension of amophos and ammonium sulphate is neutralized with ammonia to a pH of 6.5 to 7.0 at a temperature below 95 ° C, after which the reaction mixture is immediately cooled below 50 ° C. and stabilized by the addition of a bentonite dispersion.

The advantage of the present method lies in the possibility to process a suitable and available raw material containing phosphorus component - Amofos (ČSN 65 4915). The process itself is simple in terms of both technology and production. The process according to the present invention makes it possible to prepare basic stabilized highly concentrated NP suspensions containing sulfur in the form of ammonium sulphate with satisfactory storage, application and cryoscopic properties.

It should also be borne in mind that it allows the utilization of waste solutions of ammonium sulfate as well as crystalline ammonium sulfate, as they do in the caprolactam, coke oven and pigment production plants.

The realization of the invention consists, for example, in the preparation of a basic unstabilized Ni suspension of the composition 7-15,4-0 to 13,2-25,5-0 by dissolving and ammoniaizing the amophosic charge with gaseous ammonia in a solution of technical ammonium sulphate with a concentration of 10 to 40 % wt. to pH = 6.8 to 7.0 at 20 to 75 ° 0. The unstabilized NP suspension is rapidly cooled to 40 ° C and stabilized immediately or after dilution with the calculated amount of water, while cooling by dispersing the charge.

235 884 of a pre-prepared 15% sodium bentonite dispersion up to a concentration of 1.5 to 3% by weight of bentonite so that the resulting stabilized HP suspension temperature is 20-25 ° C,

It was found that the magnesium content in ammonium sulfate solutions in a concentration range of 0.5 to 5% by weight. magnesium sulfate does not affect the physico-chemical and storage properties of the HP suspensions. In ammoniacalization, some of the magnesium precipitates as ammonium magnesium phosphate, which does not increase viscosity, solid phase content and sedimentation rate. The presence of this component only slightly decreases the water-soluble component content *

It is not recommended by the method of the invention to produce a suspension with a sulfur content above 5% by weight, i.e. with an ammonium sulfate content above 25% by weight, since the flow and storage properties of the HP stabilized suspension are dramatically deteriorated due to the increase in solids content.

The dispersion and homogeneous mixing of the swollen bentonite particles in the HP suspension prevents nucleation, crystallization and sedimentation of ammonium sulfate crystals, ammonium phosphates, ammonium magnesium phosphate, and amophosic impurities.

The thus prepared stabilized HP suspensions have good storage and application properties and with a sulfur content of up to 5% by weight. they may contain up to 12 wt.%, N and 22 wt. P ^ O ^. They are suitable for direct fertilization and can also be used as a leaf fertilizer after dilution with water or as an HP fertilizer containing sulfur when blending HP mixed fertilizers with DA nitrogen base solution DA.M 390 30-0-0 or preparing HPK suspension fertilizers in cold mixing plants .

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Example 1

Weigh 8080 kg of a 18 ° C solution containing 9.90% by weight to a stirred tank mounted on a strain gauge balance equipped with a double-action paddle stirrer and water cooler. (NH4 / MgSO4 and 0.484 wt.% MgSO4) and a portion of 4200 kg of amophos 12.4-52.45-0 was added with stirring. The resulting amophos suspension was neutralized with 380 kg of ammonia gas to pH = 6.88. The resulting temperature of the reaction mixture was 65 ° C. To 12660 kg of the basic unstabilized NP suspension of 7.89-17.39-0, cooled to 21 ° C, was added 1948 kg of a 15% pre-prepared bentonite dispersion at 20.3 ° C and dispersed with stirring (1500 rpm) for 15 minutes to give 14608 kg of a stabilized NP suspension of 6.83-15.07-0 with 93.8% water-soluble component Ρ ₂ ° C at 20 ° C. The NP slurry has the following physicochemical and storage properties at 25 ° C: pH »6.92, density = 1200 kg.m> viscosity at shear rate 243 s ¹ ~ 35.3 mPa · s, solid phase content = 13.66 wt%, residue after flow test = 1.26 wt% Sedimentation volumes after storage time of 24.72 and 144 hours at 25 ° C was -98.7,

The stabilized NP slurry contains 1.40 wt. % of sulfur and 0.054 wt. magnesium. The solidification temperature of the NP suspension = -20.0 ° C.

Example 2

Weigh 4820 kg of a 18 ° C solution containing a 18 ° C solution in a stirred tank mounted on a strain-gauge balance equipped with a double-action paddle stirrer and water cooler.

16.6 wt. (NH4SO4 and 2.13 wt.% MgSO4). Add 4250 kg of ammonium 12.4-52.45-0 with stirring.

235 884 of the amophos suspension is neutralized with 330 kg of ammonia gas to a pH value of 6.67. The reaction mixture temperature after 70 minutes of neutralization is 70 ° C. To 9400 kg of unstabilized NP suspension of 10,29-23,09-0 and cooled to 40 ° C, add 1446 kg of a 15% pre-prepared 20.5 ° C bentonite dispersion. The Bentonite dispersion is dispersed for 15 minutes while cooling and stirring (1500 rpm). This gave 10846 kg of a stabilized NP suspension of 8.90-19.99-0 and temperature

22.3 ° C with 2.0 wt. bentonite. The stabilized NP suspension exhibits the following physicochemical and storage properties at 25 ° C: density = 1279 kg.m * ^, viscosity at shear rate 243 with ¹ ~ 65.3 mPa.s, pH = 6.83, solid phase content ≫ 26.26 wt.%, Residue after flow test = 2.55 wt. The sedimentation volumes after storage for 24, 72 and 144 hours at 25 ° C were 98.4,

96.5 and 99.4% by volume of NP slurry contains 2.042 wt. % of sulfur and 0.191 wt. magnesium. The solidification temperature of the stabilized NP suspension is -16.0 ° C.

Example 3

3810 kg of clarified water at 23 DEG C. are weighed into a stirred-tank mounted on a strain-gauge balance equipped with a double-action paddle stirrer and water cooler.

1010 kg of waste ammonium sulphate containing 79.21 wt. % ammonium sulfate, 10.15 wt. % MgSO4 and 10.64 wt. humidity. While stirring, 4250 kg of 12.4-52.45-0 amophos are added to the 18.2 ° C solution. The resulting slurry of amophos is neutralized with 330 kg of ammonia gas to pH = 6.67. The reaction mixture temperature after 70 minutes of neutralization is 70 ° C. To 9400 kg of unstabilized NP suspension of 10,29-23,09-0, cooled to 40,0 ° 0, add 1044 kg of pre-prepared natri-

235 884 15% bentonite dispersion at 20.5 ° C. The Bentonite dispersion is dispersed for 15 minutes while cooling and stirring (1500 rpm). 10444 kg of a basic stabilized NP slurry having a composition of 9.31-20.66-0 are obtained at 93.6% water-solubility of the component P ₂ ° 5 ° ⁰ 22.1 ° C and a bentonite content of 1.5% by weight. The stabilized NP slurry has the following physicochemical properties at 25 ° C: density = 1265 kg.m -1, viscosity at shear rate 243 s = 50.2 mPas, solid phase content - 24.3 wt%, residue after flow test = 0.95 wt. The sedimentation volumes after storage: 24.72 and 144 hours at 25 ° C were: 98.2, 98.0 and 97.9% vol. % of sulfur and 0.198 wt. magnesium. The solidification temperature of the stabilized HP suspension is -16.2 ° C.

Example 4

Weigh 4970 kg of a 20 ° C solution containing 35.41 wt.% To a stirred tank mounted on a strain gauge balance equipped with a double-action paddle stirrer and water condenser. % (NH4) ₂ SO4 and 4.62 wt. MgSO4. With stirring, 4700 kg of 12.4-52.45-0 amophos are added. The resulting suspension of amophos is neutralized with 380 kg of ammonia gas to pH = 7.00. The temperature of the reaction mixture after 75 minutes of neutralization is 75 ° C.

To 10050 kg of unstabilized NP slurry of 13.16-24.94-0, cooled to 40 ° C, add 1546 kg of a pre-treated, 20% bentonite 15% bentonite dispersion. · Bentonite dispersion with cooling and stirring (1500 rpm) dispersed for 15 minutes. This gives 11596 kg of a stabilized NP suspension of 11.45-21.58-0 at 90.81% water solubility of the PgO2 component, at a temperature of 22.3 ° C and containing 2.0 wt. bentonite. The basic stabilized NP suspension has these phyaic

«

235 884 chemical properties determined at 25 ° C: density =

1372 · kg.m ^, viscosity at shear rate 243S “ ¹ = 75,4 mPa.s, pH = 7,05, solid phase content = 48,1% by mass ·, residue after flow test = 4,25% wt. Sedimentation volumes after storage time ^W 24, 72 and 144 hours were 99.1,

95.9 and 95.4 wt. The stabilized NP suspension contains 4.21 wt. sulfur and 0.40% by weight of magnesium · freezing point is -21.5 ° C.

Example 5

Weigh 4820 kg of a 18.2 ° C solution containing 16.60% by weight (NH 4 gSO 4 and 2.13% by weight MgSO 4) into a stirred reactor, placed on a strain gauge equipped with a double-action paddle stirrer and a water cooler. 4850 kg of amophos 12.4-52.45-0 are added with stirring, resulting in an amophos suspension which is neutralized with 380 kg of ammonia gas to pH = 6.77. The reaction mixture temperature after 68 minutes of neutralization is 68.8 ° C. To 10050 kg of IIP suspension of 11.53-25.37-0, cooled to 40 ° C, add 1547 kg of a pre-treated 15% bentonite dispersed bentonite dispersion at 23.7 ° C. (1500 rev / min) is dispersed for 15 min. give 11597 kg HP stabilized basic slurry composition of 9,84-21,70-0 at 93.7% water solubility component Ρ ^ ₂ 0, and containing 2.0 wt.% bentonite The basic stabilized IIP suspension has these physicochemical properties determined é at 25 ° G: density = 1298 kg.m -1, viscosity at shear rate 243 s ^ * = 69.2 mPa.s, pH ~ 6.87, solid phase content = 28.2% by weight, residue after flow test = 3.13 wt. The sedimentation volumes after 24, 72 and 144 hours of storage at 25 ° C were 98.9, 97.3 and 96.1 vol% respectively. The stabilized NP suspension contained 1.909 wt%. sulfur and 0.179 wt% magnesium. The freezing temperature is -20.2 ° C.

Example 6

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Weigh 4820 kg of a 20 ° C solution containing 16.60 wt.% To a stirred reactor mounted on a strain gauge balance equipped with a double-action paddle stirrer and water condenser. (NH4SO4 and 2.13 wt% MgSO4).

4850 kg of 12.4-52.45-0 amophos are added under stirring. The resulting suspension of amophos is neutralized with 380 kg of ammonia gas to pH = 6.77. The temperature of the reaction mixture after 68 minutes of neutralization was 68.8 ° C. To 10050 kg of unstabilized NP slurry of 11.53-25.37-0, cooled to 40 ° C, was added 1117 kg of a preformed, 15% bentonite dispersion at 22 ° C. The Bentonite dispersion is dispersed for 15 minutes while cooling and stirring (1500 rpm). 11167 kg of a basic stabilized NP suspension having a composition of 10.03-22.52-0 are formed at 92.9% water-solubility of the PgO 2 component at a temperature of 23.4 ° C and containing 1.5 wt. bentonite. The basic stabilized NP slurry has the following physicochemical properties determined at 25 ° C: density = 1287 kg.ni. ^, viscosity at shear rate 243 s ¹¹ = 75.5 mPa.s, pH = 6.77, solids content The sedimentation volumes after 24, 72 and 144 hours of storage were: 98.3, 97.9 and 97.9% vol. -19.5 ° C. The stabilized NP suspension contains 1.983 wt. % sulfur and 0.185 wt. magnesium.

Example 7

Weigh 3513 kg of clarified water at 20 ° C and 897 kg of technical ammonium sulphate from coking plants containing 20.1% by weight to a stirred reactor, placed on a strain gauge equipped with a double-action paddle stirrer and water cooler. N. Ammonium sulphate solution at 15.3 ° C is added to the solution

235 884 mixing weighs 4512 kg of amophos 12.4-52.45-0 · The resulting amophos suspension ee neutralizes 1128 kg of ammonia water containing 25.0 wt. NH 2 (20.56 wt% N) up to pH = 6.70 · The reaction mixture temperature after 35 minutes of neutralization is 63 ° 0 · K 10050 kg of unstabilized NP suspension of 9,67-23,55-0, When cooled to 40 ° C, 1117 kg of a preformed, bentonite 15% bentonite dispersion at 22 ° C are prepared. The Bentonite dispersion is dispersed for 15 minutes while cooling and stirring (1500 rpm). 11167 kg of a stabilized NP slurry of 8.70-21.20-0 at 94.2% water solubility of the PgO2 component at a temperature of 25 ° C and containing 1.5 wt. bentonite. The basic stabilized NP slurry has the following physicochemical properties determined at 25 ° C: density = 1260 kg.m ** \ viscosity at loop strain rate 243 = 49.2 mPa.s, pH = 6.75, solids content and 23 8% by weight, residue after flow test »0.98% by weight. The sedimentation volumes after storage for 24, 72 and 144 hours at 25 ° C were: 98.1, 97.9 and 97.8 vol%. · The freezing temperature is -16.0 ° C.

Claims (1)

SUBJECT OF THE INVENTION 235 884 Process for preparing a basic stabilized NP suspension containing up to 5 wt. characterized in that the aqueous suspension of ammonium and ammonium sulphate is neutralized with ammonia to a pH of 6.5 to 7.0 at a temperature below 95 ° C, after which the reaction mixture is immediately cooled below 50 ° C and stabilized by the addition of a bentonite dispersion .