SU1353765A1 - Method of obtaining granulated ammonium nitrate - Google Patents

Abstract

The invention relates to a method for producing granulated ammonium nitrate, relates to the stage of stabilization of fertilizer granules and allows to increase the strength and homogeneity of the granules by stabilizing the II-IV modification transition. The mineral additive containing boron 0.05 wt.% And calcium oxide 0.05 wt.% Is crushed to 200 µm, dehydrated at 200-250 ° C and introduced into the melt of ammonium nitrate (99.4-99.7%). Next, the melt is granulated, the strength of the granules is 2.3 ± 0.3 kg / granule (3.5 ± iO, 4 MPa). Neither curves during cooling fixed modifications transitions I-II-IV. The alternation of modifications contributes to the improvement of the quality of the finished product by reducing the defect structure, the strength of the product increases 1.3-2.8 times. 1 tab. Q SA joint venture with Oi ate

Description

The invention relates to methods for producing ammonium nitrate and relates to the stage of stabilization of fertilizer granules.

The aim of the invention is to increase the strength and uniformity of the granules by stabilizing the modification transition II-IV.

PRI me R. 4. Mineral addition of transition - (minus) 1.7%,

Caps containing 0.05 wt.% boron and 0.05 wt.% calcium oxide are crushed to 200 µm, dehydrated at 200-250 ° C and introduced into the melt of ammonium nitrate (99.4-99.7% NH4. NO,); Further, the melt 15 is granulated. The strength of the granules is 2.5iO, 3 kg / granule (3.5 ± 0.4 MPa). On the DTA curves, modifying transitions.

Data on this and other examples of the method are given in the table. .

As can be seen from the table, the optimum concentration range of the mineral can is 25–0.05–0.1 wt.% In terms of boron. Reducing or increasing this interval is impractical, since in the first case there will be no effect of improving the quality and stabilization of ammonium nitrate, and in the second, there will not be a further increase in its strength.

The proposed mineral additive, which enriches nitrate with boron, also has a conditioning effect. This will replace the deficient sulfate-phosphate additive in ammonium nitrate with a mineral one. At the same time, the strength of the product will increase 1.3-2.8 times, and the spread of this parameter will decrease from 50% to 10%, which indicates the stabilization of the particle size distribution. Such an effect is achieved: thanks to the absence of silicon in an additive, since the latter significantly worsens the conditions of granulation of ammonium nitrate.

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and for the transition and 111- IV, respectively (plus) 1.3 and 3.7%, i.e. 5.0%. From the above data it is clear that the transition II - IV, in contrast to the transitions, proceeds with minimal volume and structural changes, which should contribute to obtaining more durable granules.

The ability to effect and stabilize transition II is determined by its kinetics, which, in turn, depends on a number of factors, including the composition of the additive.

Therefore, the proposed additive is primarily a conditioning agent and, in addition, enriching ammonium nitrate with boron.

Thus, a new quantitative composition of the mineral additive provides an increase in the quality of ammonium nitrate.

Claims (1)

Invention Formula The method of obtaining granulated ammonium nitrate by introducing a boron-containing additive into the water, followed by granulation, is used in order to increase the strength and homogeneity of the granules, as a boron-containing additive. Calcium or magnesium borate are contained in a content of 1 0.05-0.1% of boron, 0.19- 0.49% of magnesium oxide or 0.05-0.166 of calcium oxide, the rest is impurities, in an amount of 0.24- 0.7.6 wt.%. No, the dewatering property of the proposed mineral additive is manifested in the fact that when cooling the ammonium nitrate melt, a modification transition occurs instead of 11-III and 111 and IV, The volume-deformation changes of ammonium nitrate in this case constitute and for the transition and 111- IV, respectively (plus) 1.3 and 3.7%, i.e. 5.0%. From the above data it is clear that the transition II - IV, in contrast to the transitions, proceeds with minimal volume and structural changes, which should contribute to obtaining more durable granules. The ability to effect and stabilize transition II is determined by its kinetics, which, in turn, depends on a number of factors, including the composition of the additive. Therefore, the proposed additive is primarily a conditioning agent and, in addition, enriching ammonium nitrate with boron. Thus, a new quantitative composition of the mineral additive provides an increase in the quality of ammonium nitrate. Invention Formula The method of obtaining granulated ammonium nitrate by introducing a boron-containing additive into the water, followed by granulation, is used in order to increase the strength and homogeneity of the granules, as a boron-containing additive. Calcium or magnesium borate are contained in a content of 1 0.05-0.1% of boron, 0.19- 0.49% of magnesium oxide or 0.05-0.166 of calcium oxide, the rest is impurities, in an amount of 0.24- 0.7.6 wt.%. By famous Alternation of modifications to improve the quality of the finished product by reducing the defectiveness of the structure.