KR20210065593A - Manufacturing method of solid hydroxylammonium nitrate and solid hydroxylammonium nitrate manufactured therefrom - Google Patents

Abstract

The present invention relates to a method for manufacturing solid ammonium hydroxide nitrate, and the solid ammonium hydroxide nitrate manufactured therefrom, wherein the method comprises the steps of: a) neutralizing a first solution containing nitric acid and a second solution containing amine hydroxide; b) concentrating and cooling the reaction solution under reduced pressure after the neutralization reaction; and c) adding an organic solvent to the concentrated and cooled reaction solution, and forming crystals to obtain the solid ammonium hydroxide nitrate.

Description

Method for producing solid ammonium hydroxide nitrate and solid ammonium hydroxide nitrate prepared therefrom

The present invention relates to a method for preparing a solid ammonium hydroxide nitrate and a solid ammonium hydroxide nitrate prepared therefrom.

Hydrazine, which is frequently used as a high-energy material in the aerospace or defense field, is very toxic and difficult to handle, so research on various alternative materials is being actively conducted.

In particular, it has high performance specific thrust that can reduce the consumption of propellants in the thruster field used for orbital maneuvering and attitude control of spacecraft such as rockets, artificial satellites, and space probes in recent years, and has excellent operability, handling safety and environmental friendliness. Quality is demanded. For this reason, reaction control systems (RCS) that use low-toxic propellants called 'Green Propellants' instead of toxic hydrazine are attracting attention.

The eco-friendly, low-toxicity propellants currently being studied include hydrazinium nitroformate [HNF, N ₂ H ₅ C(NO ₂ ) ₃ ], hydroxylammonium nitrate [HAN, NH ₃ OHNO ₃ ] and ammonium dinitramide [ADN, NH ₄ N(NO) ₂ ) ₂ ] series, etc. Among them, the HAN (hereinafter referred to as ammonium hydroxide nitrate) has an excellent driving force when applied as a propellant because it has a sufficient amount of oxygen for optimal performance as an ionic liquid fuel, and has a low freezing point and high density. It has very good physical properties. In addition, since it has high solubility in water even at a temperature below the boiling point of water, it has the advantage of lowering the final combustion temperature at the bottom of the thruster by using water as a solvent.

When the ammonium hydroxide nitrate as described above is used as a monopropellant material, the most important physical property required among the requirements is purity. However, when supplying liquid ammonium hydroxide nitrate, there is a limit to supplying a constant quality because the purity varies depending on the method of calculating the content.

Accordingly, in order to provide high-purity ammonium hydroxide nitrate, various synthesis methods have been performed as follows.

First, as described in U.S. Patent No. 5,182,092, ammonium hydroxide nitrate, a semi-product, was synthesized through the exchange reaction of cations and anions of alkali nitrate and ammonium hydroxide hydrochloride. However, since by-products such as sodium chloride (NaCl) or potassium chloride (KCl) may coexist in this synthesis process, a method of removing them is additionally required, but there is a limit to increasing the purity because it is difficult to completely remove them.

In addition, it has been previously reported that the purity can be increased by concentration under reduced pressure in the method of synthesizing ammonium hydroxide nitrate by the neutralization reaction of a nitric acid solution and an amine hydroxide solution, but as a result, a liquid phase is prepared to provide a high purity of 87% or more It is difficult. Therefore, an attempt was made to remove moisture using a high-temperature concentration method, but the risk of explosion could not be excluded.

In another method, solid ammonium hydroxide nitrate was provided as a solid phase separation process using a freezing point temporarily formed by supercooling liquid ammonium hydroxide nitrate for high purity. However, this method has a problem in that moisture is absorbed inside the solid grains during the filtration process and melts again in the form of a slurry, making it difficult to provide high purity.

Accordingly, in order to provide a constant quality, it is urgent to provide ammonium hydroxide nitrate having a high purity of 87% or more by effectively removing moisture.

US Patent Publication No. 5,182,092 (Jan. 26, 1993)

It is an object of the present invention to provide a method for obtaining ammonium hydroxide nitrate of high purity.

Another object of the present invention is to provide a method for providing ammonium hydroxide nitrate in a solid phase.

A method for preparing solid ammonium hydroxide nitrate according to the present invention comprises the steps of: a) neutralizing a first solution containing nitric acid and a second solution containing amine hydroxide; b) concentrating and cooling the reaction solution under reduced pressure after the neutralization reaction; and c) adding an organic solvent to the concentrated and cooled reaction solution, and forming crystals to obtain solid ammonium hydroxide nitrate.

The first solution according to an embodiment of the present invention may contain 50% by weight or more of nitric acid based on the total weight.

Step a) according to an embodiment of the present invention may be performed at a low temperature of 20° C. or less.

Step a) according to an embodiment of the present invention may be to drop the second solution to the first solution.

Step a) according to an embodiment of the present invention may be to drop the first solution to the second solution.

The amine hydroxide of the second solution may be mixed in an amount of 1.1 to 3.0 equivalents per 1 equivalent of nitric acid of the first solution according to an embodiment of the present invention.

Step b) according to an embodiment of the present invention may be performed at 40° C. or less.

The organic solvent according to an embodiment of the present invention may be any one or a mixed solvent of two or more selected from a ketone-based compound and an alcohol-based compound.

The solid ammonium hydroxide nitrate according to an embodiment of the present invention may have a yield of 70% or more.

The solid ammonium hydroxide nitrate according to an embodiment of the present invention may have a purity of 87% or more.

Another embodiment of the present invention is a solid ammonium hydroxide nitrate prepared by the above-described method for preparing a solid ammonium hydroxide nitrate.

The method for producing solid ammonium hydroxide nitrate according to the present invention has the advantage that liquid ammonium hydroxide nitrate can be obtained in a solid phase. Furthermore, there is an advantage in that the solid phase can be maintained instead of the slurry phase even after being obtained as a solid phase.

In addition, the method for producing solid ammonium hydroxide nitrate according to the present invention has the advantage that it is possible to significantly reduce the moisture content and to produce high-purity ammonium hydroxide nitrate. Specifically, ammonium hydroxide nitrate of high purity of 87% or more can be obtained.

In addition, the method for producing a solid ammonium hydroxide nitrate according to the present invention has the advantage that it can be obtained in a solid phase and in high purity even if it is provided from a solution containing a high concentration of nitric acid.

1 shows FT-IR results of solid ammonium hydroxide nitrate according to an embodiment of the present invention.
2 shows the XRF results of solid ammonium hydroxide nitrate according to an embodiment of the present invention.

Advantages and features of embodiments of the present invention, and methods of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms to be described later are terms defined in consideration of functions in an embodiment of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

To achieve the above object, this invention relates to a method for producing a solid ammonium hydroxide nitrate and a solid ammonium hydroxide nitrate prepared therefrom.

If we explain this invention in detail, it is as follows.

A method for preparing solid ammonium hydroxide nitrate according to the present invention comprises the steps of: a) neutralizing a first solution containing nitric acid and a second solution containing amine hydroxide; b) concentrating and cooling the reaction solution under reduced pressure after the neutralization reaction; and c) adding an organic solvent to the concentrated and cooled reaction solution, and forming crystals to obtain solid ammonium hydroxide nitrate.

The existing method for producing ammonium hydroxide nitrate was difficult to produce with high purity due to the limitation of the liquid phase, and even if it was prepared in a solid phase, it was changed into a slurry shape due to moisture absorption at the same time as the solid phase was obtained, so that it could not be provided with high purity.

In contrast, the method for producing solid ammonium hydroxide nitrate according to the present invention minimizes the moisture content of ammonium hydroxide nitrate, and specifically, it is possible to provide a solid ammonium hydroxide nitrate having a purity of 87% or more.

In addition, in the conventional method for producing ammonium hydroxide nitrate, it is difficult to shorten the time when preparing a high-concentration nitric acid solution, and it is difficult to produce high purity according to oxidation acceleration. However, the method for producing solid ammonium hydroxide nitrate according to the present invention is 50% by weight. It is possible to provide high-purity and solid ammonium hydroxide nitric acid even with the above high-concentration nitric acid solution.

In addition, ammonium hydroxide nitrate provided in the liquid phase is difficult to be supplied at a constant content because the content changes rapidly even with a small amount of moisture around, whereas the solid ammonium hydroxide nitrate prepared by the manufacturing method according to the present invention has a constant content and purity when supplied. It is possible to provide uniform quality during supply and to express excellent efficiency even at the same content.

Step a) according to the present invention is a step of neutralizing the first solution containing nitric acid and the second solution containing amine hydroxide. Ammonium hydroxide nitrate may be synthesized through the neutralization reaction.

According to an embodiment of the present invention, the first solution may contain 50% by weight or more of nitric acid based on the total weight. Specifically, it may contain 50 to 70% by weight, preferably 55 to 70% by weight. In the conventional manufacturing method of ammonium hydroxide nitrate, when a high concentration of nitric acid is included, the improvement in purity is insignificant according to oxidation acceleration. In contrast, the present invention has excellent reaction stability even if it contains a high concentration of nitric acid as described above, can obtain high-purity ammonium hydroxide nitrate, and can also be prepared in a solid phase, and the prepared solid ammonium hydroxide nitrate is in the form of a slurry It does not deteriorate and can maintain its solid form for a long time.

According to an embodiment of the present invention, the first solution may include nitric acid and a first solvent, and specifically, the first solvent is not particularly limited as long as it can dissolve nitric acid, but, for example, it may be water. have.

According to an embodiment of the present invention, the second solution may include amine hydroxide and a second solvent, and specifically, the second solvent is not particularly limited as long as it can dissolve amine hydroxide, but for example, It could be water.

According to an embodiment of the present invention, step a) may be performed at a temperature lower than room temperature. For example, it may be carried out at a low temperature of 20 ℃ or less. Specifically, it can be carried out at a low temperature of -10 to 20 °C, preferably 0 to 20 °C, more preferably 0 to 15 °C. By carrying out at a low temperature as described above, higher purity ammonium hydroxide nitrate can be obtained.

According to an embodiment of the present invention, step a) may be performed for 10 minutes to 2 hours, but is not limited thereto.

According to an embodiment of the present invention, the method of mixing the first solution and the second solution in step a) is not particularly limited, but may be, for example, mixing the second solution with the first solution. Alternatively, the second solution may be mixed with the first solution. Preferably, the second solution may be added dropwise to the first solution. Alternatively, the first solution may be added dropwise to the second solution. When mixed by dropwise as described above, reaction stability can be improved and high-purity production can be induced.

According to an embodiment of the present invention, 1.1 to 3.0 equivalents of amine hydroxide in the second solution may be mixed per 1 equivalent of nitric acid in the first solution. Preferably, 1.1 to 2.5 equivalents of amine hydroxide in the second solution per 1 equivalent of nitric acid in the first solution may be mixed. When mixed as described above, decomposition of the generated ammonium hydroxide nitrate during the neutralization reaction can be prevented, and the stability of the reaction solution can be improved to further improve the yield, thereby securing a large amount of high-purity ammonium hydroxide nitrate.

Step b) according to the present invention is a step of concentrating and cooling the reaction solution under reduced pressure after the neutralization reaction. Specifically, the step of cooling after concentration under reduced pressure may be performed.

According to an embodiment of the present invention, the yield can be further improved while removing unreacted products and by-products through the reduced pressure concentration. In addition, by passing through the cooling, it is possible to obtain a high purity ammonium hydroxide nitrate by actively inducing crystallization later.

According to an embodiment of the present invention, step b) may be performed at 40° C. or less. Specifically, the concentration under reduced pressure in step b) may be carried out at 40° C. or less. Preferably it can be carried out at 10 to 40 ℃, more preferably 20 to 40 ℃. When carried out under the conditions as described above, only unreacted substances and by-products in the reactor are selectively removed, and ammonium hydroxide nitrate can be obtained in high yield.

In addition, specifically, the cooling in step b) may be to provide the reaction solution to 20 ℃ or less, preferably 0 to 20 ℃, more preferably 0 to 15 ℃ may be cooling. After that, crystallization can be induced in step c), and high purity ammonium hydroxide nitrate can be obtained as a solid phase.

Step c) according to the present invention is a step of obtaining a solid ammonium hydroxide nitrate by adding an organic solvent to the concentrated and cooled reaction solution to form crystals. By going through the above steps, it is possible to finally obtain a solid ammonium hydroxide nitrate. At this time, by introducing the reaction solution to the organic solvent, it is possible to induce rapid crystallization to obtain a solid phase.

According to an embodiment of the present invention, the organic solvent may be any one or a mixture of two or more selected from a ketone-based compound and an alcohol-based compound. As a specific example, the ketone-based compound may be any one or a mixture of two or more selected from acetone, methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone. The alcohol-based compound may be any one or a mixture of two or more selected from methanol, ethanol isopropanol and butanol. When only the alcohol-based compound is included, the water content is high, so it can be changed into a slurry shape, and thus, preferably, the ketone-based compound may be necessarily included to minimize the water content. More preferably, acetone may be included.

In the case of using the organic solvent as described above, it is possible to induce crystallization of the reaction solution to obtain a solid ammonium hydroxide nitrate, and to further improve the yield and purity.

According to an embodiment of the present invention, the organic solvent may be added in a ratio of 1.5 to 3 volume with respect to the total volume of the reaction solution. Preferably, it may be added in a volume ratio of 1.5 to 2.5. By adding the organic solvent in excess as described above, it is possible to minimize the moisture content and suppress the moisture absorption of ammonium hydroxide nitrate.

According to an embodiment of the present invention, the solid ammonium hydroxide nitrate obtained in step c) may be further filtered and washed.

According to an embodiment of the present invention, the washing may be performed by using any one washing solution selected from a ketone-based compound, a hydrocarbon-based compound, and an ether-based compound, or by sequentially using two or more washing solutions. As a specific example, the ketone-based compound may be any one or a mixture of two or more selected from acetone, methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone. In addition, the hydrocarbon-based compound may be any one or a mixture of two or more selected from hexane, cyclohexane and isooctane. In addition, the ether-based compound may be any one or a mixture of two or more selected from diethyl ether, tetrahydrofuran, methyl tetrahydrofuran and tetraethylene glycol dimethyl ether. In order to suppress the hygroscopicity of the solid ammonium hydroxide nitrate, washing may be preferably performed using a ketone-based compound and a hydrocarbon-based compound, respectively. Although the order is not particularly limited, washing may be performed using, for example, a ketone-based compound and a hydrocarbon-based compound sequentially.

According to an embodiment of the present invention, the step of drying the solid ammonium hydroxide nitrate obtained in step c) may be further performed. The drying may be carried out at 40° C. or less, specifically 25 to 38° C., preferably 25 to 35° C. The drying may be performed for 30 minutes to 2 hours, preferably for 1 to 2 hours. When it is carried out under the dry conditions as described above, it is possible to suppress the slurrying of solid ammonium hydroxide nitrate, and it is possible to secure ammonium hydroxide nitrate of high purity.

According to an embodiment of the present invention, the yield of the solid ammonium hydroxide nitrate may be 70% or more. Specifically, it may be 74 to 99.9%, preferably 80 to 99.9%, more preferably 86 to 99%. The method for preparing solid ammonium hydroxide nitrate according to the present invention can obtain ammonium hydroxide nitrate in high yield by minimizing by-products with stable reactivity.

According to an embodiment of the present invention, the solid ammonium hydroxide nitrate may have a purity of 87% or more. Specifically, it may be 90 to 99.9%, preferably 95 to 99.9%, more preferably 96 to 99.9%.

The method for producing solid ammonium hydroxide nitrate according to the present invention is capable of obtaining ammonium hydroxide nitrate, which existed in a liquid phase according to the existing slurrying, etc., in a solid phase and at the same time minimizing the moisture content to obtain ammonium hydroxide nitrate with high purity and high yield. groundbreaking way.

Another embodiment of the present invention is a solid ammonium hydroxide nitrate prepared by the above-described method for preparing a solid ammonium hydroxide nitrate. For example, it may be a solid ammonium hydroxide nitrate having a purity of 87% or more. Specifically, the purity may be 90 to 99.9%, preferably 95 to 99.9%, more preferably 96 to 99.9%.

Ammonium hydroxide nitrate is used as a propellant in the aerospace field such as rockets, and in this case, it is very important to predict the generation of energy calculated very accurately to use it as a propellant. Therefore, the existing ammonium hydroxide nitrate provided in liquid form has strong hygroscopicity even in a small amount of moisture in the surrounding environment, so it is difficult to calculate the content of the final ammonium hydroxide nitrate provided, so it is difficult to provide uniform quality.

On the other hand, the solid ammonium hydroxide nitrate prepared by the method for producing a solid ammonium hydroxide nitrate according to the present invention is provided in a solid phase, so it is easy to calculate the correct content, and moreover, it can be provided in high purity, so that high quality and high efficiency even at the same content It can be expressed and can be applied to various fields that require it, and it is particularly excellent as a propellant in the aerospace field.

Hereinafter, the present invention will be specifically described by way of Examples and Comparative Examples. The examples below are only for helping understanding of the present invention, and the scope of the present invention is not limited by the examples below.

[Method of measuring physical properties]

1. Moisture content

It used a Coulometric KF titrator Metrohm 831 Moisture meter, and that to the cell that can titration by Applying the heat after inserting the jacket containing the sample in order to remove water contained in hydroxide, ammonium nitrate in the oven evaporation of water in the sample, This method was used to measure the amount of moisture by the Karl Fischer method.

2. FT-IR

In order to confirm the composition of ammonium hydroxide nitrate, FT-IR analysis was performed, and the device used was a JASCO V-460 FT/IR Spectrometer (Wavelength Range: 650~4000nm; Miracle Single reflectance ATR used; Resolution: 4cm ^-1 ; Scantimes: 30times ).

3. XRD

Ammonium hydroxide nitrate was measured with XRD, equipment, manufactured by Rigaku, and “X-ray diffraction Ultima IV” was used to raise the sample so that it was level on the plate and then measured from 20° to 140° under the following conditions. The measurement conditions were: tube voltage: 40 kV, tube current: 40 kmA, X-ray: CuKα (wavelength λ=1.　541 Å). The peak was confirmed by the X-ray diffraction measurement.

[Example 1]

Into a 150 ml round flask, 21 ml of an aqueous nitric acid solution having a concentration of 70 wt% was added, and the temperature was maintained at 10°C or less in a cooling bath. Thereafter, 40 ml of an aqueous amine hydroxide solution having a concentration of 50% by weight was slowly dropped over 30 minutes while maintaining the temperature inside the reactor at 10° C. or less using a dropping funnel. After the dropwise addition, the mixture was stirred for 30 minutes while maintaining the temperature below 10°C.

After stirring, the reaction solution was concentrated under reduced pressure at 38° C. for 30 minutes using a vacuum concentrator. Thereafter, the concentrated reaction solution was cooled to 10°C. To the cooled reaction solution, 50 ml of acetone was slowly added to form white crystals. The resulting white crystals were rapidly filtered at room temperature using a glass filter, and the filtered crystals were washed by sequentially adding 20 ml of acetone and 20 ml of n-hexane. The obtained crystals were dried at constant temperature in an atmosphere of 25° C. for 60 minutes to obtain 27.8 g (88%) of solid ammonium hydroxide nitrate.

[Example 2]

After maintaining the 150 ml round flask at 10° C. or less in a cooling bath, 22 ml of an aqueous amine hydroxide solution having a concentration of 50 wt % was added. Thereafter, 10 ml of an aqueous solution of nitric acid having a concentration of 70% by weight was slowly dropped over 30 minutes while maintaining the temperature inside the reactor at 10° C. or less using a dropping funnel. After the dropwise addition, the mixture was stirred for 30 minutes while maintaining the temperature below 10°C.

After stirring, the reaction solution was concentrated under reduced pressure at 38° C. for 30 minutes using a vacuum concentrator. Thereafter, the concentrated reaction solution was cooled to 10°C. To the cooled reaction solution, 50 ml of ethanol was slowly added to form white crystals. The resulting white crystals were rapidly filtered at room temperature using a glass filter, and the filtered crystals were washed by sequentially adding 20 ml of ethanol and 20 ml of diethyl ether. The obtained crystals were subjected to constant temperature drying in an atmosphere of 25° C. for 60 minutes to obtain 8.5 g (56%) of solid ammonium hydroxide nitrate (s-HAN).

[Example 3]

After maintaining the 150 ml round flask at 10° C. or less in a cooling bath, 23 ml of an aqueous amine hydroxide solution having a concentration of 50 wt% was added. Thereafter, 15 ml of an aqueous solution of nitric acid having a concentration of 70 wt% was slowly dropped over 30 minutes while maintaining the temperature inside the reactor at 10° C. or less using a dropping funnel. After the dropwise addition, the mixture was stirred for 30 minutes while maintaining the temperature below 10°C.

After stirring, the reaction solution was concentrated under reduced pressure at 38° C. for 30 minutes using a vacuum concentrator. Thereafter, the concentrated reaction solution was cooled to 10°C. To the cooled reaction solution, 20 ml of acetone and 20 ml of isopropanol were sequentially added slowly to form white crystals. The resulting white crystals were rapidly filtered at room temperature using a glass filter, and the filtered crystals were washed by sequentially adding 20 ml of acetone and 20 ml of n-hexane. The obtained crystals were subjected to constant temperature drying in an atmosphere of 25° C. for 60 minutes to obtain 19.2 g (85%) of solid ammonium hydroxide nitrate (s-HAN).

[Example 4]

After maintaining the 150 ml round flask at 10° C. or less in a cooling bath, 23 ml of an aqueous amine hydroxide solution having a concentration of 50 wt% was added. Thereafter, 15 ml of an aqueous solution of nitric acid having a concentration of 70 wt% was slowly dropped over 30 minutes while maintaining the temperature inside the reactor at 10° C. or less using a dropping funnel. After the dropwise addition, the mixture was stirred for 30 minutes while maintaining the temperature below 10°C.

After stirring, the reaction solution was concentrated under reduced pressure at 38° C. for 30 minutes using a vacuum concentrator. Thereafter, the concentrated reaction solution was cooled to 10°C. To the cooled reaction solution, 20 ml of acetone and 20 ml of ethanol were sequentially slowly added to form white crystals. The resulting white crystals were quickly filtered at room temperature using a glass filter, and the filtered crystals were washed by sequentially adding 20 ml of acetone and 20 ml of diethyl ether. The obtained crystals were dried at constant temperature for 60 minutes in an atmosphere of 25° C. to obtain 16.7 g (74%) of solid ammonium hydroxide nitrate (s-HAN).

[Example 5]

It was carried out in the same manner as in Example 1, except that it was carried out at room temperature (25° C.) without using a cooling bath. The yield of the obtained solid ammonium hydroxide nitrate (s-HAN) was 22.99 g (73%).

[Example 6]

The same procedure was performed except that in Example 1, an aqueous nitric acid solution having a concentration of 70% by weight was diluted to 50% by weight. The yield of the obtained solid ammonium hydroxide nitrate (s-HAN) was 16.41 g (60%).

[Example 7]

The same procedure was carried out in Example 1, except that 20 ml of an aqueous solution of 50% by weight of amine hydroxide was added. The yield of solid ammonium hydroxide nitrate (s-HAN) was 16.2 g (70%).

[Example 8]

The same procedure was performed except that in Example 1, concentration under reduced pressure was carried out at 60 °C. The yield of solid ammonium hydroxide nitrate (s-HAN) was 22.37 g (71%).

[Comparative Example 1]

Liquid ammonium hydroxide nitrate (1-HAN) concentrated under reduced pressure in Example 1 was obtained and used.

As shown in FIG. 1 of the solid ammonium hydroxide nitrate prepared in Example 1, it was confirmed that ammonium hydroxide nitrate was prepared through FT-IR structural analysis. Specifically, it was confirmed that the bonding of the _{NH 3} OH ⁺ group appeared at ^{1,750-1,760 cm -1} and 1,540-15,20 cm ^-1 , and the NO bonding of the ^{NO 3-} group was located between ^{1387-1250 cm -1 .} In addition, NH ₃ OH ⁺ OH bonding was confirmed at ^{3,550-3,200cm -1} , 1,620-1,600cm ^-1 and 600-700cm ^{-1 .} Furthermore, it can be confirmed that as the moisture content is _{reduced, the bonding of the NH 3} OH ⁺ group moves to a lower wavelength region, thereby obtaining high-purity ammonium hydroxide nitrate. Specific purity was confirmed using reversed-phase high-performance liquid chromatography (HPLC), and it was possible to determine high purity with a single peak.

In addition, as shown in FIG. 2, the solid ammonium hydroxide nitrate prepared in Example 1 showed diffraction peaks in the regions of 2θ = 23° and 35° through XRD structural analysis, confirming that ammonium hydroxide nitrate was prepared. did.

Moisture content according to Examples 1 to 8 and Comparative Example 1 of the present invention is shown in Table 1.

moisture content
(%) s-HAN or l-HAN
water
(%) Example 1 3.23 96.71 Example 2 12.31 87.68 Example 3 4.31 95.66 Example 4 5.42 94.55 Example 5 7.99 91.89 Example 6 8.25 89.59 Example 7 8.88 91.53 Example 8 8.88 91.01 Comparative Example 1 21.04 75.15

As shown in Table 1, it was confirmed that the method for preparing solid ammonium hydroxide nitrate according to the present invention minimizes the moisture content and can produce high-purity solid ammonium hydroxide nitrate. Furthermore, it was confirmed that a manufacturing method with high yield and suppressed side reactions could be provided. Comparing Examples 1 to 4, when crystals were formed with an organic solvent of a ketone-based compound, solid hydroxylation having superior purity It was confirmed that ammonium nitrate can be obtained.

In addition, comparing Examples 5 and 8 compared to Example 1, when carried out at a temperature of 20 ° C or less in the neutralization step or at a temperature of 40 ° C or less during reduced pressure, the reactivity is further improved to improve the yield and purity. was able to confirm that

Furthermore, since ammonium hydroxide nitrate has a melting point of about 48° C. and is performed at a higher temperature, even if a solid phase is formed into a crystal, it changes back to a liquid phase, so it can react sensitively to the temperature change in each step. When the conditions are maintained, it is preferable to obtain a solid ammonium hydroxide nitrate of superior purity.

In addition, when comparing Example 6 with Example 1, it was confirmed that when the nitric acid content of the first solution was used at a high concentration, solid ammonium hydroxide nitrate having a higher purity could be obtained.

In addition, comparing Example 1 to Example 7, it was confirmed that the efficiency can be further improved when the equivalent ratio of the first solution and the second solution is 1:1.1 to 3.0.

Moreover, as in Comparative Example 1, when liquid ammonium hydroxide nitrate was provided, it could be confirmed that the moisture content was not only high, but also the moisture content continued to increase with time after production.

When preparing ammonium hydroxide nitrate by the method for preparing solid ammonium hydroxide nitrate according to the present invention, it is possible to prevent it from being obtained as a solid and changing its shape to a slurry within a short time. Moreover, it can provide ammonium hydroxide nitrate in high yield or high purity, so it is excellently applicable as a propellant in aerospace fields such as rockets that require accurate purity and content.

In the present invention, as described above been described by the specific details and exemplary embodiments and the drawing, which only be provided to assist the overall understanding of the present invention, the present invention is not limited to the embodiment of the present invention If you grow up with common knowledge in the field you belong to, various modifications and variations are possible from these descriptions.

Therefore, the idea according to this invention should not be limited to the described embodiments and should not be defined, and not only the claims described later, but also all the variations in the claims that are equivalent to or equivalent to the claimed ones. will be.

Claims (11)

a) neutralizing a first solution containing nitric acid and a second solution containing amine hydroxide;
b) concentrating and cooling the reaction solution under reduced pressure after the neutralization reaction; and
c) adding an organic solvent to the concentrated and cooled reaction solution, forming crystals to obtain solid ammonium hydroxide nitrate;
A method for producing a solid ammonium hydroxide nitrate comprising a. The method of claim 1,
The first solution is a method for producing a solid ammonium hydroxide nitrate containing 50% by weight or more of nitric acid based on the total weight. The method of claim 1,
Step a) is a method for producing a solid ammonium hydroxide nitrate is carried out at a low temperature of 20 ℃ or less. The method of claim 1,
The step a) is a method for producing a solid ammonium hydroxide nitrate by dropping the second solution to the first solution. The method of claim 1,
The step a) is a method for producing a solid ammonium hydroxide nitrate by dropping the first solution to the second solution. The method of claim 1,
A method for producing a solid ammonium hydroxide nitrate by mixing 1.1 to 3.0 equivalents of amine hydroxide in the second solution per 1 equivalent of nitric acid in the first solution. The method of claim 1,
Step b) is a method for producing a solid ammonium hydroxide nitrate is carried out at 40 ℃ or less. The method of claim 1,
The organic solvent is any one or a mixed solvent of two or more selected from a ketone-based compound and an alcohol-based compound, a method for producing a solid ammonium hydroxide nitrate The method of claim 1,
The solid ammonium hydroxide nitrate is a method for producing a solid ammonium hydroxide nitrate having a yield of 70% or more The method of claim 1,
The solid ammonium hydroxide nitrate is a method for producing a solid ammonium hydroxide nitrate having a purity of 87% or more A solid ammonium hydroxide nitrate prepared by the method for preparing a solid ammonium hydroxide nitrate according to any one of claims 1 to 10.

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