Moisture-absorption-preventing potassium nitrate material as well as preparation method and application thereof

Abstract

The invention discloses an anti-moisture-absorption potassium nitrate material as well as a preparation method and application thereof, and belongs to the technical field of solid propellant materials. The preparation method of the anti-moisture absorption potassium nitrate material comprises the following steps: mixing potassium nitrate with a dispersion liquid, and then mixing with a binder solution; wherein the dispersion liquid is obtained by dispersing a shell material in an anti-solvent of potassium nitrate; the binder solution is obtained by dissolving a binder in a good solvent of potassium nitrate. The preparation method is easy to implement and industrialize, the product is stable, the shell layer is complete and high in strength, the phenomenon of strong moisture absorption during blending of potassium nitrate and ammonium perchlorate (AP) in a solid propellant system can be effectively solved, a remarkable moisture absorption prevention effect is achieved, and the method can be popularized to solve the problem of hygroscopicity deterioration of other mixed moisture absorption materials.

Description

Technical Field

[0001] This invention relates to the field of solid propellant materials technology, and more specifically, to a moisture-resistant potassium nitrate material, its preparation method, and its application. Background Technology

[0002] Potassium nitrate is a mature, low-cost, and safe oxidant. Due to its advantages such as easy availability, low sensitivity, good thermal stability, and a relatively high critical relative humidity (25℃, 92%RH), it is widely used in various solid propellant systems, including traditional black powder, carbon black / potassium nitrate (CPN) high-temperature gas generators, boron / potassium nitrate (B / KNO3) micro solid rocket propellants, and cutting projectiles. However, when potassium nitrate is mixed with ammonium perchlorate (AP), ion exchange easily occurs in humid environments, forming highly hygroscopic ammonium nitrate. This leads to increased moisture absorption of the propellant, making it difficult to meet the complex storage environment requirements of solid propellants.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a moisture-proof potassium nitrate material, its preparation method, and its application, so as to solve or improve the above-mentioned technical problems.

[0005] This invention can be implemented as follows: In a first aspect, the present invention provides a method for preparing a moisture-proof potassium nitrate material, comprising the following steps: mixing potassium nitrate with a dispersion and then mixing it with a binder solution; The dispersion is obtained by dispersing the shell material in the antisolvent of potassium nitrate; the binder solution is obtained by dissolving the binder in the good solvent of potassium nitrate.

[0006] In an optional embodiment, the shell material comprises 15% to 25% of potassium nitrate. The mass concentration of the shell material in the dispersion is 0.3%~1%.

[0007] In an optional embodiment, the particle size of the shell material is 1 μm to 10 μm; And / or, the particle size of potassium nitrate is 150μm~500μm.

[0008] In an optional embodiment, the shell material includes at least one of aluminum powder, alumina particles, and zirconium silicate powder; And / or, the antisolvent includes at least one of chloroform, cyclohexane, liquid paraffin and n-hexane.

[0009] In an optional embodiment, the dispersion is obtained by ultrasonication and stirring of the shell material in an antisolvent; Preferably, the ultrasonic power is 1.5kW~2.5kW and the ultrasonic time is 5min~20min; Preferably, the stirring speed is 500 rpm to 750 rpm.

[0010] In an optional embodiment, the adhesive has a mass of 0.1% to 0.5% of potassium nitrate. The mass concentration of the adhesive in the adhesive solution is 5%~20%.

[0011] In an optional embodiment, the binder includes at least one or more of cationic polyacrylamide, polyacrylic acid, and polyvinyl alcohol; And / or, good solvents include at least one of water, methanol, ethanol and glycerol.

[0012] In an optional embodiment, potassium nitrate is added to a dispersion, and then to a binder solution, and the mixture is stirred to react, thereby obtaining a moisture-proof potassium nitrate material. Preferably, the stirring speed is 500 rpm to 750 rpm, and the stirring time is 3 h to 5 h; Preferably, after adding potassium nitrate to the dispersion, wait 5 to 15 seconds before adding it to the binder solution.

[0013] Secondly, the present invention provides a moisture-proof potassium nitrate material, which is prepared by any of the preparation methods described in the foregoing embodiments; Preferably, the moisture-proof potassium nitrate material includes potassium nitrate and a shell coating the surface of the potassium nitrate; Preferably, the thickness of the shell is 1μm to 30μm.

[0014] Thirdly, the present invention provides the application of the moisture-resistant potassium nitrate material as described above in solid propellant systems, explosives or other energetic materials.

[0015] The beneficial effects of this invention include: The method for preparing the moisture-proof potassium nitrate material provided by this invention is easy to implement and industrialize. By adsorbing and fixing the shell material with a binder, a core-shell structure potassium nitrate material is obtained. This moisture-proof potassium nitrate material product is stable, has an intact shell, and high strength. It can effectively prevent AP from contacting the potassium nitrate material and causing ion exchange to form a highly hygroscopic ammonium nitrate material, thereby achieving a significant moisture-proof effect. This method can be extended to solve the problem of deterioration of the hygroscopicity of other mixed hygroscopic materials. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 The images show the SEM and EDS images of the moisture-absorbing potassium nitrate material prepared in Example 1 of this invention. Figure 2 The images show the SEM and EDS images of the moisture-absorbing potassium nitrate material prepared in Example 2 of this invention. Figure 3 The images show the SEM and EDS images of the moisture-absorbing potassium nitrate material prepared in Example 3 of this invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0019] The following is a detailed description of the moisture-absorbing potassium nitrate material provided by the present invention, its preparation method, and its application.

[0020] This invention provides a method for preparing a moisture-absorbing potassium nitrate material, comprising the following steps: mixing potassium nitrate with a dispersion and then mixing it with a binder solution; The dispersion is obtained by dispersing the shell material in the antisolvent of potassium nitrate; the binder solution is obtained by dissolving the binder in the good solvent of potassium nitrate.

[0021] In some alternative embodiments, potassium nitrate is first added to the dispersion, and then added to the binder solution, and the mixture is stirred to react, thereby obtaining a moisture-resistant potassium nitrate material. More preferably, potassium nitrate is first added to the dispersion, and after an interval of 5 to 15 seconds (e.g., 5 seconds, 10 seconds, or 15 seconds), it is added to the binder solution, and the mixture is stirred to react, thereby obtaining a moisture-resistant potassium nitrate material.

[0022] The stirring speed can be between 500 rpm and 750 rpm, such as 500 rpm, 600 rpm, 700 rpm, or 750 rpm, or other values ​​within the range of 500 rpm to 750 rpm. The stirring time can be between 3 hours and 5 hours, such as 3 hours, 4 hours, or 5 hours, or other values ​​within the range of 3 hours to 5 hours.

[0023] It should be noted that if the interval between adding potassium nitrate to the dispersion and then adding the binder solution is too long (e.g., more than 15 seconds), it will not be conducive to the dispersion of the shell material, and the agglomeration of the shell material will be aggravated after the binder solution is added.

[0024] In some optional embodiments, the particle size of potassium nitrate can be 150 μm to 500 μm, such as 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm or 500 μm, or other values ​​in the range of 150 μm to 500 μm.

[0025] If the particle size of potassium nitrate is less than 150 μm, it is detrimental to the strength of the shell material coating layer; if the particle size of potassium nitrate is greater than 500 μm, it is detrimental to the process performance of solid propellants after the addition of this material.

[0026] In some alternative embodiments, the dispersion is obtained by ultrasonication and stirring of the shell material in an antisolvent.

[0027] The ultrasonic power can be 1.5kW to 2.5kW, such as 1.5kW, 2kW, or 2.5kW, or other values ​​within the range of 1.5kW to 2.5kW. The ultrasonic time can be 5min to 20min, such as 5min, 10min, 15min, or 20min, or other values ​​within the range of 5min to 20min.

[0028] The stirring speed can be 500rpm~750rpm, such as 500rpm, 550rpm, 600rpm, 650rpm, 700rpm or 750rpm, or other values ​​within the range of 500rpm~750rpm.

[0029] In some alternative embodiments, the particle size of the shell material can be 1μm to 10μm, such as 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm or 10μm, or other values ​​in the range of 1μm to 10μm.

[0030] If the particle size of the shell material is less than 1 μm, it is prone to electrostatic self-agglomeration, which is not conducive to its uniform dispersion in the dispersion liquid; if the particle size of the shell material is greater than 10 μm, it is not conducive to the material's moisture-proof performance.

[0031] In some alternative embodiments, the mass of the shell material can be 15% to 25% of potassium nitrate, such as 15%, 18%, 20%, 22% or 25%, or other values ​​within the range of 15% to 25%.

[0032] If the mass of the shell material is less than 15% of the potassium nitrate, the product's moisture-wicking performance will be reduced; if the mass of the shell material is more than 25% of the potassium nitrate, there will be no significant improvement in moisture-wicking performance compared to products in the 15%~25% range, and the cost will increase.

[0033] The mass concentration of the shell material in the dispersion can be 0.3% to 1%, such as 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%, or other values ​​within the range of 0.3% to 1%.

[0034] The shell material may, by way of example, include at least one of aluminum powder, alumina particles, and zirconium silicate powder. The antisolvent may, by way of example, include at least one of chloroform, cyclohexane, liquid paraffin, and n-hexane.

[0035] The aforementioned shell material is derived from solid propellant components. This core-shell structure of moisture-resistant potassium nitrate material exhibits good compatibility with the solid propellant system. By coating the surface of potassium nitrate with this shell material to form a dense, moisture-resistant shell, contact between AP and potassium nitrate can be effectively prevented, achieving a significant moisture-resistant effect.

[0036] In some alternative embodiments, the mass of the binder can be 0.1% to 0.5% of potassium nitrate, such as 0.1%, 0.2%, 0.3%, 0.4% or 0.5%, or other values ​​within the range of 0.1% to 0.5%.

[0037] If the mass of the binder is less than 0.1% of the potassium nitrate, the bonding strength of the binder will be insufficient to meet the mixing requirements of the solid propellant, and the shell will be damaged after mixing, leading to an increase in moisture absorption. If the mass of the binder is greater than 0.5% of the potassium nitrate, too much potassium nitrate solvent will cause damage to the potassium nitrate material structure, affecting the subsequent formation of the shell structure and leading to an increase in moisture absorption.

[0038] The mass concentration of the adhesive in the adhesive solution can be 5% to 20%, such as 5%, 10%, 15% or 20%, or other values ​​within the range of 5% to 20%.

[0039] In some alternative embodiments, the adhesive may exemplary include at least one or more of cationic polyacrylamide, polyacrylic acid, and polyvinyl alcohol.

[0040] This invention employs cationic or strongly hydrogen-bonded polymeric binder materials, which have a strong adsorption effect on the shell material. This is beneficial for producing a core-shell structure with advantages of density and high strength. During processes such as solid propellant mixing, the integrity of the core-shell structure can be maintained, thereby ensuring its moisture resistance.

[0041] Good solvents may, by way of example, include at least one of water, methanol, ethanol and glycerol.

[0042] Building upon the above, this invention utilizes an adhesive material to adsorb and fix the shell material, resulting in a core-shell structured potassium nitrate material. This effectively prevents contact between potassium nitrate (AP) and the potassium nitrate material, thus preventing ion exchange and the formation of a highly hygroscopic ammonium nitrate material, thereby achieving a significant moisture-proof effect. This preparation method is easy to implement and industrialize, producing a stable product with a intact and strong shell.

[0043] Accordingly, the present invention also provides a moisture-proof potassium nitrate material, which is prepared by the above-described preparation method.

[0044] This moisture-absorbing potassium nitrate material includes potassium nitrate and a shell coating the surface of the potassium nitrate. The shell is mainly formed by the shell material.

[0045] In some alternative implementations, the thickness of the shell can be 1μm to 30μm, such as 1μm, 2μm, 5μm, 10μm, 15μm, 20μm, 25μm or 30μm, or other values ​​within the range of 1μm to 30μm.

[0046] If the shell thickness is less than 1 μm, it is detrimental to the material's moisture resistance; if the shell thickness is greater than 30 μm, it is detrimental to the energy performance of the solid propellant after the addition of this material.

[0047] Furthermore, the present invention also provides an application of the above-mentioned moisture-resistant potassium nitrate material in solid propellant systems, explosives, or other energetic materials.

[0048] In some alternative embodiments, the moisture-resistant potassium nitrate material provided by the present invention is used in solid propellants, which can significantly reduce the moisture absorption rate of solid propellant blocks.

[0049] In some preferred embodiments, the moisture-absorbing potassium nitrate material and ammonium perchlorate (AP) are placed in an environment with a temperature of 25°C and a relative humidity of 75% for 48 hours at a mass ratio of 1:1, and the moisture absorption rate of the mixture does not exceed 1%, such as 0.37% to 0.9%.

[0050] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0051] Example 1 This embodiment provides a moisture-absorbing potassium nitrate material, the preparation method of which includes: S1: Prepare the adhesive solution.

[0052] Weigh 0.05g of cationic polyacrylamide, dissolve it in 1g of deionized water, and stir magnetically until completely dissolved to obtain an adhesive solution with a mass concentration of approximately 5%.

[0053] S2: Prepare a dispersion.

[0054] Measure 300g of liquid paraffin into a 250mL three-necked flask, and add 2.0g of spherical aluminum powder with an average particle size of 5μm. Place the three-necked flask in a 2kW ultrasonic cleaner and sonicate for 10min, while stirring with a mechanical stirrer at 600rpm to obtain a uniform and stable dispersion with a mass concentration of approximately 0.67%.

[0055] S3: Coating reaction.

[0056] Weigh 10g of potassium nitrate powder with a particle size of 150μm~300μm and quickly add it to the dispersion while stirring at 600rpm. After waiting for about 10s, quickly pour all the binder solution into the system and continue to stir at 600rpm at room temperature for 4 hours.

[0057] S4: Post-processing.

[0058] After the reaction was complete, the mixture was vacuum filtered using a Buchner funnel and washed three times with n-hexane to remove residual antisolvent. The filter cake was then dried in a vacuum drying oven at 60°C for 6 hours to obtain the moisture-resistant potassium nitrate material.

[0059] The SEM and EDS results of the moisture-absorbing potassium nitrate material prepared in this embodiment are as follows: Figure 1 As shown, by Figure 1 It can be seen that the Al signal on the particle surface is strong, and only a small amount of K signal can be observed, indicating the successful formation of the Al powder shell layer.

[0060] Example 2 This embodiment provides a moisture-absorbing potassium nitrate material, the preparation method of which includes: S1: Prepare the adhesive solution.

[0061] Weigh 0.03g of polyacrylic acid and dissolve it in a mixed solvent of 0.3g of methanol and deionized water (mass ratio 1:1). Stir magnetically until completely dissolved to obtain an adhesive solution with a mass concentration of approximately 10%.

[0062] S2: Prepare a dispersion.

[0063] Measure 400g of chloroform into a 500mL three-necked flask, and add 2.5g of alumina particles with a diameter of 1μm~3μm. Place the three-necked flask in a 2kW ultrasonic cleaner and sonicate for 15min, while stirring with a mechanical stirrer at 750rpm to obtain a uniform and stable dispersion with a mass concentration of approximately 0.625%.

[0064] S3: Coating reaction.

[0065] Weigh 10g of potassium nitrate powder with a particle size of 300μm~400μm and quickly add it to the dispersion while stirring at 750rpm. After waiting for about 5 seconds, quickly pour all the binder solution into the system and continue to stir at 750rpm at room temperature for 3 hours.

[0066] S4: Post-processing.

[0067] After the reaction was complete, the mixture was vacuum filtered using a Buchner funnel and washed twice with n-hexane to remove residual antisolvent. The filter cake was then dried in a vacuum drying oven at 50°C for 8 hours to obtain the moisture-resistant potassium nitrate material.

[0068] The SEM and EDS results of the moisture-absorbing potassium nitrate material prepared in this embodiment are as follows: Figure 2 As shown, by Figure 2 It can be seen that the A and O signals on the particle surface are strong, and only a small amount of K signal can be observed, indicating the successful formation of the Al2O3 powder shell layer.

[0069] Example 3 This embodiment provides a moisture-absorbing potassium nitrate material, the preparation method of which includes: S1: Prepare the adhesive solution.

[0070] Weigh 0.025g of polyvinyl alcohol (PVA-1788) and dissolve it in a mixed solvent of 0.5g of glycerol and deionized water (mass ratio 1:1). Stir magnetically until completely dissolved to obtain an adhesive solution with a mass concentration of approximately 5%.

[0071] S2: Prepare a dispersion.

[0072] Measure 300g of n-hexane into a 250mL three-necked flask, and add 2.0g of zirconium silicate powder with a particle size of 8μm~10μm. Place the three-necked flask in a 2kW ultrasonic cleaner and sonicate for 20min, while stirring with a mechanical stirrer at 500rpm to obtain a uniform and stable dispersion with a mass concentration of approximately 0.67%.

[0073] S3: Coating reaction.

[0074] Weigh 10g of potassium nitrate powder with a particle size of 400μm~500μm and quickly add it to the dispersion while stirring at 500rpm. After waiting for about 15s, quickly pour all the binder solution into the system and continue to stir at 500rpm at room temperature for 5h.

[0075] S4: Post-processing.

[0076] After the reaction was complete, the mixture was vacuum filtered using a Buchner funnel and washed with a small amount of chloroform to remove residual antisolvent. The filter cake was then dried in a vacuum drying oven at 55°C for 6 hours to obtain the moisture-resistant potassium nitrate material.

[0077] The SEM and EDS results of the moisture-absorbing potassium nitrate material prepared in this embodiment are as follows: Figure 3 As shown, by Figure 3 It can be seen that the presence of Zr signal on the particle surface indicates that the zirconium silicate powder has successfully acted on the potassium nitrate surface.

[0078] Experimental Example 1 The moisture-absorbing potassium nitrate material prepared in Examples 1-3 was mixed with ammonium perchlorate (AP) at a mass ratio of 1:1 and placed in an environment with a temperature of 25°C and a relative humidity of 75% for 48 hours. The moisture absorption rate of the mixture was then tested, and the results are shown in Table 1.

[0079] Uncoated raw potassium nitrate and AP were placed in an environment of 25°C and 75% relative humidity for 48 hours at a mass ratio of 1:1. The moisture absorption rate of the mixture was then measured, and the results are shown in Table 1.

[0080] Table 1 Moisture Absorption Rate

[0081] As can be seen from Table 1, the moisture-proof potassium nitrate material prepared in Example 1 has significantly reduced hygroscopicity compared to the original potassium nitrate without a shell.

[0082] The moisture-proof potassium nitrate material prepared in Example 2 also significantly reduced hygroscopicity compared to the original potassium nitrate without a shell. This example shows that metal oxides can also form an effective moisture-proof shell.

[0083] The moisture-resistant potassium nitrate material prepared in Example 3 significantly reduced hygroscopicity compared to the original potassium nitrate without a shell. This product is suitable for propellant formulations that require coarser oxidants. This example demonstrates that this method can achieve complete coating even for large-particle-size potassium nitrate.

[0084] Experimental Example 2 This test case aims to investigate the effect of the amount of shell material on performance. The steps are basically the same as in Example 1, except that the amount of aluminum powder in the shell material is changed.

[0085] Sample A: The shell material content is 10 wt% potassium nitrate; Sample B: The shell material content is 15 wt% potassium nitrate; Sample C: The shell material content is 25 wt% potassium nitrate; Sample D: The amount of shell material used is 30 wt% potassium nitrate.

[0086] According to the test method of Experiment Example 1, the moisture absorption rate results of the above samples are shown in Table 2.

[0087] Table 2 Moisture Absorption Rate

[0088] As shown in Table 2, when the amount of shell material is in the range of 15wt% to 25wt% of potassium nitrate, the product's moisture-proof performance improves with the increase of shell material content. When the amount of shell material is less than 15wt% of potassium nitrate, the product's moisture-proof performance decreases, but it is still better than the uncoated sample. When the amount of shell material is greater than 30wt% of potassium nitrate, there is no significant improvement in moisture-proof performance compared to the 15wt% to 25wt% range, and the cost increases.

[0089] Experimental Example 3 This test case aims to investigate the effect of adhesive dosage on shell strength. The procedure is basically the same as in Example 2, except that the amount of polyacrylic acid adhesive is changed.

[0090] Sample E: The amount of adhesive used is 0.05 wt% of potassium nitrate; Sample F: The amount of adhesive used was 0.1 wt% of potassium nitrate; Sample G: The amount of adhesive used was 0.3 wt% of potassium nitrate; Sample H: The amount of adhesive used is 0.7 wt% of potassium nitrate.

[0091] According to the test method of Experiment Example 1, the moisture absorption rate results of the above samples are shown in Table 3.

[0092] Table 3 Moisture Absorption Rate

[0093] As shown in Table 3, when the amount of binder is in the range of 0.1wt% to 0.5wt% of potassium nitrate, the product has better moisture-proof performance, and the shell integrity and strength are also higher, which can withstand the force of the subsequent mixing process. When the amount of binder is less than 0.1wt% of potassium nitrate, the bonding strength of the binder is difficult to meet the mixing requirements of solid propellant, and the shell is damaged after mixing, resulting in an increase in moisture absorption. When the amount of binder is greater than 0.5wt% of potassium nitrate, too much potassium nitrate solvent to dissolve the binder will cause damage to the potassium nitrate material structure, affecting the subsequent formation of the shell structure, and thus the moisture absorption rate will increase.

[0094] In summary, the method for preparing the moisture-proof potassium nitrate material provided by this invention is easy to implement and industrialize. The prepared moisture-proof potassium nitrate material product is stable, has an intact shell, and high strength. It can effectively solve the strong moisture absorption phenomenon when potassium nitrate and ammonium perchlorate (AP) are mixed in a solid propellant system, achieving a significant moisture-proof effect. This method can be extended to solve the problem of deterioration of the moisture absorption of other mixed moisture-absorbing materials.

[0095] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a moisture-absorbing potassium nitrate material, characterized in that, Includes the following steps: Potassium nitrate is mixed with the dispersion and then with the binder solution; The dispersion is obtained by dispersing the shell material in the antisolvent of potassium nitrate; The adhesive solution is obtained by dissolving the adhesive in a good solvent, potassium nitrate.

2. The preparation method according to claim 1, characterized in that, The mass of the shell material is 15% to 25% of the potassium nitrate. The mass concentration of the shell material in the dispersion is 0.3% to 1%.

3. The preparation method according to claim 1, characterized in that, The particle size of the shell material is 1μm~10μm; And / or, the potassium nitrate has a particle size of 150 μm to 500 μm.

4. The preparation method according to claim 1, characterized in that, The shell material includes at least one of aluminum powder, alumina particles, and zirconium silicate powder. And / or, the antisolvent includes at least one of chloroform, cyclohexane, liquid paraffin, and n-hexane.

5. The preparation method according to any one of claims 1 to 4, characterized in that, The dispersion is obtained by ultrasonication and stirring of the shell material in the antisolvent; Preferably, the ultrasonic power is 1.5kW~2.5kW and the ultrasonic time is 5min~20min; Preferably, the stirring speed is 500 rpm to 750 rpm.

6. The preparation method according to claim 1, characterized in that, The adhesive has a mass of 0.1% to 0.5% of the potassium nitrate. The adhesive solution contains 5% to 20% by mass.

7. The preparation method according to claim 1, characterized in that, The adhesive comprises at least one or more of cationic polyacrylamide, polyacrylic acid, and polyvinyl alcohol; And / or, the good solvent includes at least one of water, methanol, ethanol and glycerol.

8. The preparation method according to claim 1, characterized in that, The potassium nitrate is added to the dispersion, and then to the binder solution. The mixture is stirred and reacted to obtain the moisture-proof potassium nitrate material. Preferably, the stirring speed is 500 rpm to 750 rpm, and the stirring time is 3 h to 5 h; Preferably, after the potassium nitrate is added to the dispersion, it is added to the binder solution after an interval of 5 to 15 seconds.

9. A moisture-absorbing potassium nitrate material, characterized in that, Prepared by the preparation method according to any one of claims 1 to 8; Preferably, the moisture-absorbing potassium nitrate material includes potassium nitrate and a shell layer covering the surface of the potassium nitrate; Preferably, the thickness of the shell layer is 1μm to 30μm.

10. The application of the moisture-resistant potassium nitrate material as described in claim 9 in solid propellant systems, explosives, or other energetic materials.

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