Particle-size-adjustable low-corrosivity warm fog eliminating catalyst and preparation method thereof

Abstract

The invention relates to a particle-size-adjustable low-corrosivity warm fog eliminating catalyst and a preparation method thereof, and belongs to the technical field of manual intervention weather catalysts. The catalyst comprises the following raw materials in percentage by mass: 5%-70% of inorganic sodium salt, 0%-30% of inorganic magnesium salt, 0%-30% of inorganic potassium salt, 5%-35% of weak acid and strong alkali salt, 0.1%-5% of an anti-caking agent and 0.1%-5% of an additive. According to the catalyst, weak acid and strong alkali salts are compounded with salts, a dual corrosion-resistant mechanism of passive film protection-ion complexing is constructed, the solution conductivity is reduced, and metal corrosion is retarded; the anti-caking agent can prevent caking during storage, and the dispersity is improved; the additive can reduce the salinization risk of the soil and optimize the flowability. According to the method, high-temperature and high-pressure equipment is not needed in the preparation process, the pressure and the rotating speed can be adjusted by monitoring particle size distribution in real time through a laser particle size analyzer according to the target particle size during airflow crushing, comprehensive performance improvement of accurate particle size regulation and control, low corrosion, caking resistance and high adaptation is achieved, the cost is reduced compared with that of existing composite catalysis, and industrial production can be achieved.

Description

Technical Field

[0001] This invention relates to a low-corrosion anti-fog catalyst with adjustable particle size and its preparation method, belonging to the field of artificial weather intervention catalyst technology. Background Technology

[0002] Fog reduces visibility, severely impacting air, sea, and road traffic. At airports, dense fog can prevent aircraft from taking off and landing, causing flight delays and cancellations, resulting in significant losses for passengers and airlines. On roads, fog increases the risk of traffic accidents, endangering lives and property. Ports are typically characterized by warm sea fog, which covers a wide area, further reducing visibility, affecting ship radar performance, causing driver fatigue, and increasing maritime traffic safety risks.

[0003] Currently, artificial fog dispersal technologies mainly include cooling-based fog dispersal, dynamic fog dispersal, and catalyst seeding. Cooling-based fog dispersal (such as liquid nitrogen or dry ice seeding) has limited effectiveness against large areas of warm fog, and the equipment is expensive and difficult to transport. Dynamic fog dispersal (such as fan-driven dispersal) is only suitable for small areas and is difficult to deal with large-scale dense fog. Catalyst seeding has become the mainstream technology for dispersing warm fog due to its ease of operation and wide applicability. Its core principle is to use a hygroscopic catalyst to adsorb water vapor in the fog, forming large droplets that settle, thereby achieving fog dissipation.

[0004] Existing fog-suppressing catalysts mainly rely on traditional hygroscopic salts, such as NaCl and CaCl2, but they have the following key technical problems: 1. Challenges in Particle Size Control: Traditional salt catalysts are mostly prepared by mechanical grinding, typically with particle sizes ranging from 5 μm to 200 μm, exhibiting a wide distribution. Small particles smaller than 10 μm are easily carried away by airflow, while large particles larger than 200 μm settle too quickly. This results in less than 40% of the catalyst having an effective defogging particle size of 10 μm to 30 μm, leading to low defogging efficiency. For example, Chinese patent CN119056177 A discloses an artificial defogging catalyst, its preparation method, and its application. While this artificial defogging catalyst achieves hydrolysis through solution spraying, it does not address precise particle size control, making it unsuitable for different droplet spectra scenarios.

[0005] 2. Severe Equipment Corrosion: Salts such as NaCl and CaCl2, when dissolved, form high-concentration ionic solutions. The corrosion rate on metal equipment (such as airport runway lighting systems and ship deck machinery) can reach 0.12 mm / year, far exceeding the permissible corrosion standard of 0.05 mm / year for industrial equipment. Chinese patent application CN120079427A discloses a novel composite anti-fogging catalyst formulation and its preparation method. This catalyst is prepared by mixing calcium chloride, bentonite, molecular sieves, and silica aerosol in a specific ratio. Although the composite carrier design reduces corrosivity, it does not inhibit corrosion reactions at the ionic level, and long-term use still carries the risk of equipment corrosion and damage.

[0006] 3. Prone to hygroscopic agglomeration: Traditional salt catalysts are highly hygroscopic and easily react with moisture in the air during storage, resulting in uneven dispersion during application and a decrease in catalytic efficiency of more than 30%. Chinese patent application CN120289259A discloses a method for preparing a combustion-type warm cloud catalyst. This method solves the storage hygroscopic problem through layered casting, but the preparation process is complex and it belongs to the category of combustion-type warm cloud catalysts. 4. Poor fog-suppressing adaptability: The existing catalyst has a fixed particle size and cannot adjust the particle size according to the fog droplet spectrum (such as radiation fog dominated by small droplets and advection fog dominated by large droplets), resulting in a "negative fog-suppressing effect" in some fog conditions, such as small-particle-size catalysts aggravating droplet refinement.

[0007] While existing technologies have made improvements to address the aforementioned technical problems—for example, Chinese patent application CN120054442A discloses a warm cloud catalyst and its preparation method, in which the disclosed warm cloud catalyst is a layer of SiO2 nanoparticles with hydroxyl groups coated on the surface of NaCl; and Chinese patent application CN120079427A discloses a novel composite anti-fog catalyst formulation and its preparation method, which employs a composite support design—these existing technologies still fail to simultaneously achieve the four core requirements of "precisely adjustable particle size, low corrosion, anti-caking, and high adaptability." Therefore, developing an anti-warm fog catalyst that can overcome the bottlenecks of existing technologies has become an urgent need in the field of weather modification. Summary of the Invention

[0008] To overcome the shortcomings of existing anti-fog catalysts, such as difficulty in controlling particle size, strong equipment corrosion, easy moisture absorption and agglomeration, and poor anti-fog adaptability, this invention provides a low-corrosion anti-fog catalyst with adjustable particle size and its preparation method. Through innovative component design and preparation process, the comprehensive performance improvement of the catalyst is achieved, including "precise particle size control, low corrosion, anti-agglomeration, and high adaptability".

[0009] To achieve the objectives of this invention, the following technical solutions are provided.

[0010] A low-corrosion, fog-suppressing catalyst with adjustable particle size, wherein the components and their mass fractions are as follows, based on the total mass of the catalyst raw material (100%): Inorganic sodium salts 5% ~ 70%, Inorganic magnesium salts 0% ~ 30%, Inorganic potassium salts 0% ~ 30%, 5% ~ 35% of weak acid-strong base salts Anti-caking agent 0.1% ~ 5%, Additives: 0.1% ~ 5%; All components are powders.

[0011] Furthermore, a low-corrosion anti-fog catalyst with adjustable particle size is preferred. Based on the total mass of the catalyst raw material (100%), the components and their mass fractions are as follows: Inorganic sodium salts 5% ~ 70%, Inorganic magnesium salts 0% ~ 30%, Inorganic potassium salts 0% ~ 25%, 20% ~ 30% of weak acid-strong base salts Anti-caking agent 3% ~ 5%, Additives: 0.1% ~ 5%.

[0012] The inorganic sodium salt is at least one of sodium chloride (NaCl), sodium bromide (NaBr), and sodium sulfate (Na2SO4); preferably, it is a mixture of sodium chloride (NaCl) and sodium sulfate (Na2SO4). The inorganic sodium salt serves as the core hygroscopic component in the catalyst, providing rapid hygroscopic driving force. Compared to traditional antifogging catalysts that use NaCl alone, this invention, by combining different sodium salts, reduces chloride ion concentrations (Cl-) while maintaining the hygroscopic rate. - The content of ) initially alleviated the corrosion problem.

[0013] The inorganic magnesium salt is at least one of magnesium chloride and magnesium sulfate. The inorganic magnesium salt acts as an auxiliary moisture absorber in the catalyst, regulating the moisture absorption rate.

[0014] The inorganic potassium salt is at least one of potassium chloride and potassium sulfate. The inorganic potassium salt is used in the catalyst to optimize the moisture absorption balance and prolong the moisture absorption duration.

[0015] Inorganic magnesium salts can enhance the hygroscopic activity of the catalyst described in this invention at low temperatures of 5°C to 15°C; inorganic potassium salts can prolong the hygroscopic equilibrium time of the catalyst described in this invention. The synergistic effect of "rapid hygroscopic absorption and continuous humidity control" is achieved by combining inorganic magnesium salts and inorganic potassium salts.

[0016] The weak acid-strong base salt is at least one selected from sodium acetate, potassium acetate, calcium acetate, magnesium acetate, sodium phosphate, sodium borate, sodium metasilicate, sodium silicate, sodium carbonate, magnesium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, and magnesium bicarbonate; preferably, it is at least one selected from potassium acetate, magnesium acetate, sodium borate, and sodium metasilicate. The weak acid-strong base salt is used in the catalyst to inhibit metal corrosion and adjust the pH value. Its innovation lies in the fact that the weak acid-strong base salt, after dissolving in water, forms a weakly alkaline environment with a pH value of 8.0 to 9.5, which can react with ferric ions (Fe3+) on the metal surface. 3+ The reaction generates a Fe(OH)3 passivation film, which blocks corrosive ions such as Cl. - This inhibits electrochemical corrosion at its source, preventing the erosion of metals.

[0017] The anti-caking agent is at least one selected from magnesium stearate, ferric ammonium citrate, calcium silicate, potassium ferrocyanide, and talc; preferably, magnesium stearate, calcium silicate, or potassium ferrocyanide is used as the anti-caking agent in the catalyst to prevent the catalyst from agglomerating during storage and to improve its dispersibility.

[0018] The additive is at least one selected from silica, tricalcium phosphate, gypsum, phosphogypsum, calcium sulfite, desulfurized gypsum powder, polymaleic anhydride (HPMA), polyacrylamide, and aluminum sulfate; preferably, the additive is silica, tricalcium phosphate, or polymaleic anhydride. The additive in the catalyst is used to reduce the risk of soil salinization and optimize fluidity. Specifically, silica can improve catalyst fluidity, tricalcium phosphate can neutralize soil acidity, and polymaleic anhydride can complex metal ions, further reducing environmental risks.

[0019] A method for preparing a low-corrosion anti-fog catalyst with adjustable particle size according to the present invention, the method comprising the following steps: (1) Raw material pretreatment: Inorganic sodium salt, inorganic magnesium salt, inorganic potassium salt and weak acid strong base salt are placed in an oven and dried at 50 ℃ ~ 100 ℃ for 5 h ~ 24 h to remove moisture; then they are passed through a 20 mesh ~ 100 mesh copper sieve and the residue is taken to obtain the pretreated salt; ensure the uniformity of the initial particle size of the raw materials; (2) Premixing: Weigh the salt pretreated in step (1) according to the formula ratio, add it to the mixer, stir for 10 min to 30 min, pass it through a 20-mesh copper sieve, take the residue from the sieve, and obtain a uniform mixture A; (3) Mixing of anti-caking agent: Add anti-caking agent to mixture A obtained in step (2), stir for 5 min to 15 min, pass through a 20-100 mesh copper sieve, take the residue from the sieve to obtain mixture B, and ensure that the anti-caking agent is evenly dispersed; (4) Mixing and drying of additives: Add additives to mixture B obtained in step (3), stir for 5 min to 10 min, pass through a 40-80 mesh copper sieve, take the residue from the sieve, place it in an oven at 50 ℃ to 80 ℃ and dry for 8 h to 16 h to obtain mixture C; (5) Airflow pulverization and particle size control: The mixture C obtained in step (4) is fed into an airflow pulverizer. The particle size is precisely controlled by adjusting the pulverization pressure and the speed of the classifier wheel to obtain the pulverized dry powder product, which is the low-corrosive anti-fog catalyst with adjustable particle size described in this invention.

[0020] Furthermore, in step (1), it is preferable to dry at 80 ℃ for 12 h to remove moisture; and pass through a 60-80 mesh copper sieve; In step (3), it is preferable to stir for 10 min to 15 min and pass the mixture through a 60-80 mesh copper sieve; In step (4), it is preferable to stir for 5 min to 8 min, pass through a 40-60 mesh copper sieve, take the residue from the sieve, and dry it in an oven at 80 ℃ for 8 h to 12 h to obtain mixture C; In steps (2) to (4), the preferred stirring speed is 50 r / min to 100 r / min and the speed is consistent; In step (5), the preferred crushing pressure is 0.8 MPa ~ 1.0 MPa, and the classifying wheel speed is 3000 r / min ~ 6000 r / min.

[0021] The catalyst was vacuum-packed in an aluminum-plastic composite bag with a vacuum level of less than or equal to -0.09 MPa and stored in a moisture-proof environment.

[0022] Beneficial effects (1) The present invention provides a low-corrosion anti-fog catalyst with adjustable particle size. The catalyst is designed with low-corrosion components: by compounding weak acid and strong base salts with salts, a dual anti-corrosion mechanism of "passivation film protection - ion complexation" is constructed to reduce the conductivity of the solution and slow down metal corrosion; at the same time, the additives can neutralize soil acidity and avoid the risk of salinization. (2) The present invention provides a low-corrosion anti-fog catalyst with adjustable particle size. The catalyst utilizes the hydrophobic film design of the anti-caking agent to make the moisture absorption rate of the catalyst less than or equal to 3% and the agglomeration rate less than or equal to 8% under normal humidity conditions. After storage, it still maintains good fluidity, improves the uniformity of spreading and dispersing, and reduces the problem of catalyst spreading failure caused by agglomeration. (3) This invention provides a low-corrosion anti-fog catalyst with adjustable particle size. Compared with the traditional anti-fog catalyst NaCl, this invention reduces the Cl content by compounding different sodium salts, such as sodium chloride and sodium sulfate, while ensuring the moisture absorption rate. - Concentration initially alleviates corrosion problems; magnesium salts can enhance hygroscopic activity at low temperatures of 5℃ to 15℃, while potassium salts can prolong the hygroscopic equilibrium time. The combination of these two can achieve a synergistic effect of "rapid hygroscopic absorption and continuous humidity control"; weak acid-strong base salts, when dissolved in water, can form a weakly alkaline environment with a pH of 8.0 to 9.5, which can react with Fe on the metal surface. 3+ The reaction generates a Fe(OH)3 passivation film, which blocks Cl. - Regarding the corrosion of metals, components such as sodium metasilicate can form stable complexes with salt ions, reducing the conductivity of the solution and inhibiting electrochemical corrosion at its source; silica in the additives can improve the fluidity of the catalyst, tricalcium phosphate can neutralize soil acidity, and HPMA can complex metal ions, further reducing environmental risks. (4) The present invention provides a method for preparing a low-corrosion anti-fog catalyst with adjustable particle size. The preparation process does not require high temperature and high pressure equipment. The air jet milling process is mature and easy to industrialize. The raw materials (such as sodium chloride and sodium acetate) are all common chemical products. During air jet milling, the pressure and speed can be adjusted according to the target particle size by real-time monitoring of particle size distribution through a laser particle size analyzer. The cost is lower than that of existing composite catalysts, and industrial production can be realized. (5) This invention provides a method for preparing a low-corrosion warm fog catalyst with adjustable particle size. The method has the characteristics of precise particle size control and strong adaptability: through the combination process of "pretreatment sieving-airflow pulverization and classification", the catalyst particle size can be precisely controlled from 10 μm to 80 μm, and the effective particle size volume fraction is greater than or equal to 90%. The corresponding particle size can be selected according to the fog droplet spectrum (such as radiation fog, advection fog); and the preparation method can be extended to the production of warm cloud rain enhancement catalyst with a particle size requirement of 5 μm to 20 μm, with a wide range of applications. (6) This invention provides a low-corrosion anti-warm fog catalyst with adjustable particle size and its preparation method. Through innovative component design and preparation process, it solves the core technical problems of existing anti-warm fog catalysts. It has the advantages of adjustable particle size, low corrosion, anti-caking and high efficiency. It can be widely used in warm fog elimination operations in aviation, transportation, ports and other fields, and has significant economic and social benefits. Detailed Implementation

[0023] The present invention will be described in detail below with reference to specific embodiments, but this is not intended to limit the scope of the present invention.

[0024] In the following embodiments: Double Helix Mixer: Model: SHJ-20, Jiangsu Guibao Group Co., Ltd.; Airflow pulverizer: Model: MQW03, Weifang De'er Powder Equipment Technology Co., Ltd.; Laser particle size analyzer: Model: Mastersizer 300, Malvern Instruments Ltd.; Droplet spectrometer: Model: FM-120, DMT Corporation, USA.

[0025] Example 1 A low-corrosion anti-fog catalyst with adjustable particle size, based on a total mass of 100 g of the catalyst raw material (100%), wherein all components are powders, and the types and mass fractions of the components are shown in Table 1: Table 1

[0026] A low-corrosion, warm fog-suppressing catalyst with adjustable particle size as described in this embodiment, the method steps are as follows: (1) Raw material pretreatment: Sodium chloride, magnesium acetate and potassium acetate were placed in an oven and dried at 100 °C for 5 h. After passing through a 60-mesh copper sieve, the residue was collected to obtain the pretreated salt. (2) Premixing: Weigh 70 g sodium chloride, 6 g magnesium acetate and 20 g potassium acetate, add them to a double helix mixer, stir at 100 r / min for 10 min, pass through a 20 mesh copper sieve, take the residue, and obtain a homogeneous mixture A. (3) Mixing of anti-caking agent: Add 3.9 g of potassium ferrocyanide to mixture A, continue stirring at 100 r / min for 10 min, pass through a 60-mesh copper sieve, take the residue, and obtain a homogeneous mixture B; (4) Mixing and drying of additives: Add 0.1 g of silicon dioxide to the mixture B obtained in step (3), continue to stir at 100 r / min for 5 min, pass through a 40-mesh copper sieve, take the residue from the sieve, and dry it at 80 ℃ for 8 h to obtain mixture C; (5) Airflow pulverization and particle size control: The mixture C is fed into an airflow pulverizer with a pulverization pressure of 0.8 MPa and a classifier speed of 6000 r / min. The dry powder product obtained after pulverization is a low-corrosive anti-fog catalyst with adjustable particle size.

[0027] The catalyst was vacuum-packed in an aluminum-plastic composite bag with a vacuum level of less than or equal to -0.09 MPa and stored in a moisture-proof environment.

[0028] The performance of the low-corrosion anti-fog catalyst with adjustable particle size prepared in this embodiment was tested as follows: (1) Particle size distribution: The catalyst was measured by a laser particle size analyzer. The catalyst's Dv (50) = 22.9 μm and Dv (100) = 42.2 μm. The volume fraction of the catalyst with a particle size of 10 μm ~ 40 μm was 92.3%, which is suitable for small particle size catalysts in radiation fog. (2) Moisture absorption performance: According to GB / T 16913-2008 "Test Methods for Physical Properties of Dust - Determination of Moisture Absorption", the moisture absorption of the catalyst is 3015 mg / g at 30 ℃ and 90% RH, and 170 mg / g at 30 ℃ and 60% RH. (3) Corrosion performance: In accordance with standard CSTM 00046.10-2018 "Corrosion test of low alloy structural steel - Part 10: crevice corrosion test method" and GB10124-88 "Metallic materials laboratory uniform corrosion full immersion test method", distilled water was set as a blank control. The catalyst solution and sodium chloride solution with a mass fraction of 5% were prepared respectively. After immersing 304 stainless steel and 2024 aluminum for 17 days, crevice corrosion appeared in 304 stainless steel in sodium chloride solution. No obvious corrosion traces were found in the blank control and catalyst solution after immersion for 17 days. (4) Fog elimination effect: In a closed space, radiation fog was simulated. The droplet size was detected by a fog droplet spectrometer. The droplet size was 5 μm ~ 10 μm. After spreading 0.5 g of the catalyst, the fog transmittance increased from 0% to 75% in 5 minutes, which was 73.7% shorter than the 19 minutes required by the blank group without the catalyst.

[0029] Example 2 A low-corrosion anti-fog catalyst with adjustable particle size, wherein the total mass of the catalyst raw material is 100 g (100%), and all components are powders, the types and mass fractions of which are shown in Table 2: Table 2

[0030] A low-corrosion, warm fog-suppressing catalyst with adjustable particle size as described in this embodiment, the method steps are as follows: (1) Raw material pretreatment: Sodium chloride, magnesium chloride, potassium sulfate and sodium borate were placed in an oven and dried at 50 °C for 24 h. The residue was then passed through an 80-mesh copper sieve to obtain the pretreated salt. (2) Premixing: Weigh 5 g sodium chloride, 30 g magnesium chloride, 25 g potassium sulfate and 30 g sodium borate, add them to a double helix mixer, stir at 60 r / min for 30 min, pass through a 20 mesh copper sieve, take the residue, and obtain a homogeneous mixture A. (3) Mixing of anti-caking agent: Add 5 g of calcium silicate to mixture A, continue stirring at 60 r / min for 15 min, pass through an 80-mesh copper sieve, take the residue from the sieve, and obtain a homogeneous mixture B; (4) Mixing and drying of additives: Add 5g of tricalcium phosphate to mixture B, continue stirring at 60 r / min for 8 min, pass through a 60-mesh copper sieve, take the residue from the sieve and place it in an oven, dry at 80 ℃ for 12 h to obtain mixture C; (5) Pulverization and particle size control of airflow: The mixture C is fed into an airflow pulverizer with a pulverization pressure of 1.0 MPa and a classifier speed of 3000 r / min. After pulverization, a dry powder product with a particle size of 40 μm ~ 80 μm is obtained, which is a low-corrosion anti-fog catalyst with adjustable particle size.

[0031] The catalyst was vacuum-packed in an aluminum-plastic composite bag with a vacuum level of less than or equal to -0.09 MPa and stored in a moisture-proof environment.

[0032] The performance of the low-corrosion anti-fog catalyst with adjustable particle size prepared in this embodiment was tested as follows: (1) Particle size distribution: The catalyst was measured by a laser particle size analyzer. The catalyst's Dv (50) = 58.6 μm and Dv (100) = 80.0 μm. The volume fraction of the catalyst with a particle size of 40 μm ~ 80 μm accounted for 91.7%, which is a large particle size catalyst suitable for advection fog. (2) Moisture absorption performance: According to GB / T 16913-2008 "Test Methods for Physical Properties of Dust - Determination of Moisture Absorption", the moisture absorption of the catalyst is 2850 mg / g at 30℃ and 90% RH, and 155 mg / g at 30℃ and 60% RH. (3) Corrosion performance: In accordance with standard CSTM 00046.10-2018 "Corrosion test of low alloy structural steel - Part 10: crevice corrosion test method" and GB10124-88 "Metallic materials laboratory uniform corrosion full immersion test method", distilled water was set as blank control. The catalyst solution and sodium chloride solution with a mass fraction of 5% were prepared respectively. After immersing 304 stainless steel and 2024 aluminum for 17 days, crevice corrosion appeared in 304 stainless steel in sodium chloride solution. No obvious corrosion traces were found in the blank control and catalyst solution after immersion for 17 days. (4) Fog elimination effect: In a closed space, advection fog was simulated. The droplet size was detected by a fog droplet spectrometer and the droplet size was 10 μm ~ 20 μm. When 0.5 g of the catalyst was spread, the fog transmittance increased from 0% to 75% in 4.5 min, which was 76.3% shorter than the 19 min required by the blank group without the catalyst.

[0033] Example 3 A low-corrosion anti-fog catalyst with adjustable particle size, wherein the total mass of the catalyst raw material is 100 g (100%), and all components are powders, the types and mass fractions of which are shown in Table 3: Table 3

[0034] A low-corrosion, warm fog-suppressing catalyst with adjustable particle size as described in this embodiment, the method steps are as follows: (1) Raw material pretreatment: Sodium chloride, sodium sulfate, magnesium sulfate, potassium sulfate and sodium metasilicate were placed in an oven and dried at 80°C for 12 h. The residue was then passed through a 60-mesh copper sieve to obtain the pretreated salt. (2) Premixing: Weigh 30 g sodium chloride, 10 g sodium sulfate, 15 g magnesium sulfate, 20 g potassium sulfate and 20 g sodium metasilicate, add them to a double helix mixer, stir at 50 r / min for 30 min, pass through a 20 mesh copper sieve, take the residue from the sieve, and obtain a homogeneous mixture A. (3) Mixing of anti-caking agent: Add 3 g of magnesium stearate to mixture A, continue stirring at 50 r / min for 10 min, pass through a 60-mesh copper sieve, take the residue from the sieve, and obtain a homogeneous mixture B; (4) Mixing and drying of additives: Add 2 g of polymaleic anhydride to mixture B, continue stirring at 50 r / min for 8 min, pass through a 50-mesh copper sieve, take the residue from the sieve, place it in an oven and dry at 80 ℃ for 9 h to obtain mixture C; (5) Airflow pulverization and particle size control: The mixture C is fed into an airflow pulverizer with a pulverization pressure of 0.9 MPa and a classifier speed of 5000 r / min. The dry powder product obtained after pulverization is a low-corrosive anti-fog catalyst with adjustable particle size.

[0035] The performance of the low-corrosion anti-fog catalyst with adjustable particle size prepared in this embodiment was tested as follows: (1) Particle size distribution: The catalyst was measured by a laser particle size analyzer. The particle size distribution was Dv(50) = 22.3 μm, Dv(100) = 76.0 μm, and the volume fraction of the catalyst with a particle size of 15 μm ~ 50 μm was 90.7%. (2) Moisture absorption performance: According to GB / T 16913-2008 "Test Methods for Physical Properties of Dust - Determination of Moisture Absorption", the moisture absorption of the catalyst is 3325 mg / g at 30 ℃ and 90% RH, and 180 mg / g at 30 ℃ and 60% RH. (3) Corrosion performance: In accordance with standard CSTM 00046.10-2018 "Corrosion test of low alloy structural steel - Part 10: crevice corrosion test method" and GB10124-88 "Metallic materials laboratory uniform corrosion full immersion test method", distilled water was set as a blank control. The catalyst solution and sodium chloride solution with a mass fraction of 5% were prepared respectively. After immersing 304 stainless steel and 2024 aluminum for 17 days, crevice corrosion appeared in 304 stainless steel in sodium chloride solution. No obvious corrosion traces were found in the blank control and catalyst solution after immersion for 17 days; suitable for the protection requirements of high equipment in airports; (4) Anti-fogging effect: In a closed space, when 0.5 g of the catalyst was spread, the fog transmittance increased from 0% to 75% in 4.1 min, which was 78.4% shorter than the 19 min required by the blank group without the catalyst.

Claims

1. A low-corrosive heating and cooling fog catalyst with adjustable particle size, characterized by: Each component and its mass fraction are as follows, taking the total mass of the catalyst raw material as 100%: Inorganic sodium salt 5% ~ 70%, Inorganic magnesium salt 0% ~ 30%, Inorganic potassium salt 0% ~ 30%, Weak acid strong base salt 5% ~ 35%, Anti-caking agent 0.1% ~ 5%, Additive 0.1% ~ 5%; Each component is a powder.

2. The low-corrosive heating and cooling fog catalyst with adjustable particle size according to claim 1, characterized in that: Each component and its mass fraction are as follows, taking the total mass of the catalyst raw material as 100%: Inorganic sodium salt 5% ~ 70%, Inorganic magnesium salt 0% ~ 30%, Inorganic potassium salt 0% ~ 25%, Weak acid strong base salt 20% ~ 30%, Anti-caking agent 3% ~ 5%, Additive 0.1% ~ 5%.

3. The low-corrosive heating and cooling fog catalyst with adjustable particle size according to claim 1 or 2, characterized in that: The inorganic sodium salt is at least one of sodium chloride, sodium bromide and sodium sulfate; The inorganic magnesium salt is at least one of magnesium chloride and magnesium sulfate; The inorganic potassium salt is at least one of potassium chloride and potassium sulfate; The weak acid strong base salt is at least one of sodium acetate, potassium acetate, calcium acetate, magnesium acetate, sodium phosphate, sodium borate, sodium metasilicate, sodium silicate, sodium carbonate, magnesium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate and magnesium bicarbonate; The anti-caking agent is at least one of magnesium stearate, ferric ammonium citrate, calcium silicate, potassium ferrocyanide and talc powder; The additive is at least one of silicon dioxide, tricalcium phosphate, gypsum, phosphogypsum, calcium sulfite, desulfurization gypsum powder, polymaleic anhydride, polyacrylamide and aluminum sulfate.

4. The low-corrosive heating and cooling fog catalyst with adjustable particle size according to claim 3, characterized in that: The inorganic sodium salt is sodium chloride and sodium sulfate; The weak acid strong base salt is at least one of potassium acetate, magnesium acetate, sodium borate and sodium metasilicate; The anti-caking agent is magnesium stearate, calcium silicate or potassium ferrocyanide; The additive is silicon dioxide, tricalcium phosphate or polymaleic anhydride.

5. A preparation method of the low-corrosion heating and cooling mist catalyst with adjustable particle size according to any one of claims 1 to 4, characterized in that: (1) The inorganic sodium salt, the inorganic magnesium salt, the inorganic potassium salt and the weak acid strong base salt are respectively placed in an oven and dried at 50 ℃ ~ 100 ℃ for 5 h ~ 24 h to remove water; then they are respectively passed through a 20 mesh ~ 100 mesh copper sieve, and the sieve residues are taken to obtain the pretreated salts; (2) The pretreated salts are weighed according to the formula proportion, added into a mixer, stirred for 10 min ~ 30 min, passed through a 20 mesh copper sieve, and the sieve residues are taken to obtain a uniform mixture A; (3) The anti-caking agent is added into the mixture A, stirred for 5 min ~ 15 min, passed through a 20 mesh ~ 100 mesh copper sieve, and the sieve residues are taken to obtain a mixture B; (4) The additive is added into the mixture B, stirred for 5 min ~ 10 min, passed through a 40 mesh ~ 80 mesh copper sieve, and the sieve residues are taken, dried in an oven at 50 ℃ ~ 80 ℃ for 8 h ~ 16 h to obtain a mixture C; (5) The mixture C is sent into an air flow pulverizer, and the particle size is precisely controlled by adjusting the pulverizing pressure and the rotating speed of the grading wheel to obtain a pulverized dry powder product, which is a low-corrosion heating and cooling mist catalyst with adjustable particle size.

6. The preparation method of the low-corrosion heating and cooling mist catalyst with adjustable particle size according to claim 5, characterized in that: In step (1), dry at 80 ℃ for 12 h to remove water; pass through a 60 mesh-80 mesh copper sieve; In step (3), stir for 10 min-15 min, and pass through a 60 mesh-80 mesh copper sieve; In step (4), stir for 5 min-8 min, pass through a 40 mesh-60 mesh copper sieve, take the sieve residue, and place it in an oven at 80 ℃ for drying for 8 h-12 h to obtain the mixture C; In steps (2)-(4), the stirring speed is 50 r / min-100 r / min and the speed is consistent; In step (5), the crushing pressure is 0.8 MPa-1.0 MPa, and the classification wheel speed is 3000 r / min-6000 r / min.

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