An anti-agglomerating agent and its use in the preparation of anhydrous hydrogen fluoride

Abstract

The application relates to the technical field of anhydrous hydrogen fluoride preparation, and discloses an anti-agglomerating agent and application of the anti-agglomerating agent in preparation of anhydrous hydrogen fluoride, wherein the anti-agglomerating agent comprises the following raw materials: calcium sulfate and polyethylene glycol perfluoroalkyl methyl ether. The anti-agglomerating agent can solve the problem of agglomeration of raw materials in preparation of anhydrous hydrogen fluoride by using a fluidized bed method, and can effectively utilize by-products calcium sulfate and reduce solid waste emissions. The anti-agglomerating agent is prepared by recycling by-products calcium sulfate and stirring the calcium sulfate and polyethylene glycol perfluoroalkyl methyl ether under certain conditions, the contact angle of the product reaches 105-125 DEG, the anti-agglomerating agent can effectively inhibit the agglomeration of raw materials in the fluidized bed, and the stability of the fluidized bed operation is improved; the anti-agglomerating agent is premixed with fine fluorite powder at a certain mass ratio, and then is fed into the fluidized bed, the anti-agglomerating efficiency reaches 80%, and the purity of the anhydrous hydrogen fluoride reaches 99.93%.

Description

Technical Field

[0001] This invention relates to the field of anhydrous hydrogen fluoride preparation technology, specifically to an anti-agglomeration agent and its application in the preparation of anhydrous hydrogen fluoride. Background Technology

[0002] Anhydrous hydrogen fluoride is a core raw material in the fluorochemical industry, widely used in the preparation of refrigerants, fluoropolymers, and electronic-grade fluorides. The production of anhydrous hydrogen fluoride primarily utilizes the "fluorite powder (CaF2)-concentrated sulfuric acid method." This method generates 3.5-4.0 tons of calcium sulfate as a byproduct for every ton of anhydrous hydrogen fluoride produced. When using a fluidized bed to prepare anhydrous hydrogen fluoride, the fine particles of fluorite powder (400 mesh and below), its tendency to absorb moisture, and its tendency to form agglomerates can lead to uneven bed fluidization, decreased reaction efficiency, and even equipment blockage.

[0003] Existing solutions to the aforementioned fluorite powder agglomeration problem all have significant shortcomings, making it difficult to achieve efficient industrial application. Specifically: (1) Mechanical agglomeration method: For example, the built-in mechanical agitator can effectively shear agglomerates, but its moving parts are prone to failure in the highly corrosive concentrated sulfuric acid / hydrogen fluoride environment, and the sealing structure has the risk of leakage during the agitation process. Once a leak occurs, it will cause serious safety and environmental accidents. (2) Airflow distribution method: By optimizing airflow operating parameters, stronger fluid shear force is created to break up agglomerates, but the effect is minimal for strong viscous agglomerates dominated by moisture and van der Waals forces. (3) External field enhancement method: For example, patent CN201710275539.1 uses acoustic field / centrifugal field to break up clusters. This method has drawbacks such as high energy consumption, complex equipment and difficulty in scaling up for industrial fluidized beds with large processing capacity. (4) Adding external anti-agglomeration agents: The industry has tried to introduce external particles such as SiO2 as flow aids to suppress agglomeration, but this will introduce silicon impurities into the system, resulting in a decrease in the purity and yield of hydrogen fluoride products, which cannot meet the requirements of electronic grade hydrogen fluoride. (5) Direct use of unmodified calcium sulfate: Because the surface of unmodified calcium sulfate is hydrophilic, it easily adsorbs water and forms "secondary agglomerates" with fluorite powder. The actual anti-agglomeration efficiency is only 40%-50%, which is far lower than the 65% anti-agglomeration effect of SiO2-type flow aids.

[0004] Therefore, there is an urgent need to develop an anti-agglomeration agent that can both efficiently utilize by-products and ensure stable operation of the fluidized bed in the hydrogen fluoride production process. Summary of the Invention

[0005] This invention provides an anti-agglomeration agent and its application in the preparation of anhydrous hydrogen fluoride, in order to solve the problems of easy agglomeration and excessive production of calcium sulfate by-product during the production of anhydrous hydrogen fluoride.

[0006] In a first aspect, the present invention provides an anti-agglomeration agent comprising the following raw materials: Calcium sulfate, polyethylene glycol perfluoroolefin methyl ether.

[0007] In one optional embodiment, the anti-agglomeration agent comprises the following raw materials in parts by weight: 1000 parts by weight of calcium sulfate and 1 part by weight of polyethylene glycol perfluoroolefin methyl ether.

[0008] In one alternative embodiment, the calcium sulfate includes the byproduct calcium sulfate; And / or, the chemical formula of the polyethylene glycol perfluoroolefin methyl ether is C n F 2n-1 O(CH2CH2O) m CH3, where n is an integer from 6 to 12 and m is an integer from 4 to 24; in an optional embodiment, the polyethylene glycol perfluoroolefin methyl ether is C 10 F 19 O(CH2CH2O) 22 CH3.

[0009] In one optional embodiment, the byproduct calcium sulfate is obtained by pretreatment of the calcium sulfate crude residue produced during the production of anhydrous hydrogen fluoride. It should be noted that the methods for producing anhydrous hydrogen fluoride here include the liquid-solid phase rotary kiln method and the gas-solid phase fluidized bed method. When producing hydrogen fluoride using the above two methods, a large amount of calcium sulfate coarse slag will be generated. After pretreatment, the calcium sulfate coarse slag can be used as the raw material for the anti-agglomeration agent of this invention. And / or, in the byproduct calcium sulfate, CaSO4 ≥ 90 wt%.

[0010] In one optional embodiment, the pretreatment includes the following steps: taking coarse calcium sulfate residue, screening it through a vibrating sieve to separate fine residue with a particle size ≤0.5mm, drying the obtained fine residue at 110~150℃ for 2~3h, and then grinding it to obtain calcium sulfate by-product with a particle size of 5~20μm. Furthermore, the drying temperature can be any one of 110, 115, 120, 130, 135, 140, 145, 150℃ or a range between any two values; Furthermore, the drying time can be any one of the following values: 2, 2.2, 2.4, 2.6, 2.8, 3 h, or a range between any two values.

[0011] In a second aspect, the present invention provides a method for preparing the anti-agglomeration agent according to the first aspect, comprising the following steps: According to the formula, polyethylene glycol perfluoroolefin methyl ether and calcium sulfate are mixed.

[0012] In one optional embodiment, the mixing conditions are: stirring at a speed of 2500~3000 rpm and a temperature of 80~90℃ for 3~5 hours; Furthermore, the rotational speed can be any one of 2500, 2550, 2600, 2700, 2800, 2900, 3000 rpm or a range between any two values; Furthermore, the temperature can be any one of 80, 82, 84, 85, 86, 88, 90℃ or a range between any two values; Furthermore, the stirring time can be any one of the following values: 3, 3.3, 3.7, 4, 4.3, 4.7, 5 h, or a range between any two values.

[0013] Thirdly, the present invention provides the use of the anti-agglomeration agent described in the first aspect or the anti-agglomeration agent prepared by the preparation method described in the second aspect in the production of anhydrous hydrogen fluoride.

[0014] Fourthly, the present invention provides a method for applying the anti-agglomeration agent described in the first aspect or the anti-agglomeration agent prepared by the preparation method described in the second aspect, comprising the following steps: mixing the anti-agglomeration agent with fluorite powder, and reacting it with sulfur trioxide and water vapor in a fluidized state to produce hydrogen fluoride.

[0015] In one optional embodiment, the mass ratio of the anti-agglomeration agent to fluorite powder is 1:99.

[0016] The technical solution of this invention has the following advantages: 1. The anti-agglomeration agent for the fluidized bed preparation of anhydrous hydrogen fluoride provided by this invention comprises the following raw materials: calcium sulfate and polyethylene glycol perfluoroalkenyl methyl ether. The anti-agglomeration agent prepared by this invention solves the problem of easy agglomeration of raw materials during the fluidized bed preparation of anhydrous hydrogen fluoride.

[0017] 2. The anti-agglomeration agent for the preparation of anhydrous hydrogen fluoride using the fluidized bed method provided by this invention can effectively utilize calcium sulfate, a byproduct of hydrogen fluoride production, reducing solid waste emissions. The product is prepared by recovering and utilizing the byproduct calcium sulfate, which is then purified, dried, ground, and stirred under certain conditions. This product has a contact angle of 105-125°, effectively inhibiting the agglomeration of raw materials in the fluidized bed and improving the stability of the fluidized bed operation. When this anti-agglomeration agent is premixed with fine fluorite powder at a certain mass ratio and fed into the fluidized bed, the anti-agglomeration efficiency reaches 76%. Furthermore, the introduction of this anti-agglomeration agent has no impact on the purity of anhydrous hydrogen fluoride, and the operating cost is reduced by more than 20%. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a process flow diagram of the preparation and application of the anti-agglomeration agent of the present invention. Detailed Implementation

[0020] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention by any person under the guidance of the present invention or by combining the features of the present invention with other prior art falls within the protection scope of the present invention.

[0021] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0022] The perfluoroolefin methyl ether of polyethylene glycol used in this invention has the chemical formula C. n F 2n-1 O(CH2CH2O) m CH3, where n is an integer from 6 to 12 and m is an integer from 4 to 24. In a preferred embodiment, the polyethylene glycol perfluoroolefin methyl ether is C 10 F 19 O(CH2CH2O) 22 CH3 was synthesized in the laboratory as follows: 50 mL of toluene and 50 g of tetrafluoroethylene pentamer (CAS No.: 52584-41-5) were added to a four-necked flask and heated to 70 °C, stirring until completely dissolved. Then, 5 g of N,N-dimethylamine (CAS No.: 121-69-7) was added, and while stirring and heating, polyethylene glycol monomethyl ether (HO(CH2CH2O)) was slowly added. 22 An ethanol solution of CH3 (100g) (CAS No.: 9004-74-4) was prepared at 110℃ and reacted for 1.5 hours. The solvent was then evaporated to obtain a viscous liquid C. 10 F 19 O(CH2CH2O) 22 CH3 (Reference patent: CN200710066881.7—A method for synthesizing polyethylene glycol perfluoroolefin methyl ether).

[0023] The calcium sulfate used in the following embodiments of the present invention is the calcium sulfate coarse residue produced by the preparation of anhydrous hydrogen fluoride using the "fluorite powder (CaF2)-concentrated sulfuric acid method" (gas-solid fluidized bed method). After pretreatment of the calcium sulfate coarse residue by the following steps, calcium sulfate, a raw material by-product for the preparation of anti-agglomeration agent, is obtained. Specifically, the calcium sulfate coarse residue is taken and screened by vibrating sieve to separate fine residue with a particle size ≤0.5mm. The obtained fine residue is dried at 110~150℃ for 2~3h and then ground to obtain calcium sulfate by-product with a particle size of 5~20μm.

[0024] Polyethylene glycol (PEG-2000) was purchased from Aladdin Reagents, catalog number P103730, molecular weight 2000 Da; polyethylene glycol chlorinated derivative (Cl-PEG-Cl) was purchased from Guangzhou Carbon Water Technology Co., Ltd., molecular weight 2000 Da; polyethylene glycol silane coupling agent (MPEG-Silane) was purchased from Xi'an Ruixi Biotechnology, molecular weight 3000 Da; perfluorooctanoic acid (PFOA) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.; perfluorooctane sulfonic acid (PFOS) was purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0025] Example 1 This embodiment provides a method for preparing an anti-agglomeration agent, comprising the following steps: (1) After vibrating and screening the coarse calcium sulfate residue (≤0.5mm), it is placed in a hot air dryer and dried at 130℃ for 2.5h. Then, it is ground with an air jet mill to obtain the by-product calcium sulfate (purity CaSO4 is 90%) with a particle size of 5~20μm. (2) Take 200 kg of the byproduct calcium sulfate and add it to a high-speed mixer, then add polyethylene glycol perfluoroolefin methyl ether (C 10 F 19 O(CH2CH2O) 22 0.2 kg of CH3 was added to a high-speed mixer at 3000 rpm. The jacket was heated to 85°C and stirred for 4 hours to obtain an anti-agglomeration agent.

[0026] Comparative Example 1 This comparative example provides an unmodified calcium sulfate sample, and the specific preparation steps are as follows: After vibrating and screening the coarse calcium sulfate residue (<0.5mm), it was placed in a hot air dryer and dried at 130℃ for 2.5h. Then, it was ground with an air jet mill to obtain 200kg of calcium sulfate (purity CaSO4 90wt%) as a byproduct with a particle size of 5~20μm.

[0027] Comparative Example 2 This comparative example provides a method for preparing an anti-agglomeration agent, comprising the following steps: (1) After vibrating and screening the coarse calcium sulfate residue (≤0.5mm), it is placed in a hot air dryer and dried at 130℃ for 2.5h. Then, it is ground with an air jet mill to obtain the by-product calcium sulfate with a particle size of 5~20μm (purity CaSO4 is 90wt%). (2) Take 200 kg of by-product calcium sulfate and add it into a high-speed mixer. Then add 0.2 kg of polyethylene glycol (PEG-2000), turn on the high-speed mixer, turn the speed to 3000 rpm, heat the jacket to 85°C, and stir for 4 hours to obtain the anti-agglomeration agent.

[0028] Comparative Example 3 This comparative example provides a method for preparing an anti-agglomeration agent, comprising the following steps: (1) After vibrating and screening the coarse calcium sulfate residue (≤0.5mm), it is placed in a hot air dryer and dried at 130℃ for 2.5h. Then, it is ground with an air jet mill to obtain the by-product calcium sulfate with a particle size of 5~20μm (purity CaSO4 is 90wt%). (2) First, add 200 kg of by-product calcium sulfate into a high-speed mixer, then add 0.2 kg of polyethylene glycol chlorinated derivative (Cl-PEG-Cl), turn on the high-speed mixer, rotate at 3000 rpm, heat the jacket to 85°C, and stir for 4 hours to obtain the anti-agglomeration agent.

[0029] Comparative Example 4 This comparative example provides a method for preparing an anti-agglomeration agent, comprising the following steps: (1) After vibrating and screening the coarse calcium sulfate residue (≤0.5mm), it is placed in a hot air dryer and dried at 130℃ for 2.5h. Then, it is ground with an air jet mill to obtain the by-product calcium sulfate with a particle size of 5~20μm (purity CaSO4 is 90wt%). (2) First, add 200 kg of by-product calcium sulfate into a high-speed mixer, then add 0.2 kg of polyethylene glycol silane coupling agent (MPEG-Silane), turn on the high-speed mixer, rotate at 3000 rpm, heat the jacket to 85°C, and stir for 4 hours to obtain the anti-agglomeration agent.

[0030] Comparative Example 5 This comparative example provides a method for preparing an anti-agglomeration agent, comprising the following steps: (1) After vibrating and screening the coarse calcium sulfate residue (≤0.5mm), it is placed in a hot air dryer and dried at 130℃ for 2.5h. Then, it is ground with an air jet mill to obtain the by-product calcium sulfate with a particle size of 5~20μm (purity CaSO4 is 90wt%). (2) First, add 200 kg of the byproduct calcium sulfate into a high-speed mixer, and then add perfluorooctanoic acid (PFOA, chemical formula C8HF) dropwise. 15Take 0.2 kg of O2, turn on the high-speed mixer, turn the speed to 3000 rpm, heat the jacket to 85°C, stir for 4 hours to obtain the anti-agglomeration agent.

[0031] Comparative Example 6 This comparative example provides a method for preparing an anti-agglomeration agent, comprising the following steps: (1) After vibrating and screening the coarse calcium sulfate residue (≤0.5mm), put it into a hot air dryer and dry it at 130℃ for 2.5h. Then grind it with an air jet mill to obtain 200kg of by-product calcium sulfate (purity CaSO4 is 90wt%) with a particle size of 5~20μm. (2) First, add 200 kg of the byproduct calcium sulfate into a high-speed mixer, and then add perfluorooctanoic acid (PFOS, chemical formula C8HF) dropwise. 17 Take 0.2 kg of O3S, turn on the high-speed mixer, turn the speed to 3000 rpm, heat the jacket to 85℃, stir for 4 hours to obtain the anti-agglomeration agent.

[0032] Comparative Example 7 This comparative example provides an anti-agglomeration agent, which is polyethylene glycol (PEG-2000).

[0033] Comparative Example 8 This comparative example provides an anti-agglomeration agent, which is polyethylene glycol perfluoroolefin methyl ether (C... 10 F 19 O(CH2CH2O) 22 CH3).

[0034] Experimental Example 1: Performance Analysis of Anti-agglomeration Agent 1. Scanning electron microscopy (SEM) analysis The SEM images of the unmodified CaSO4 prepared in Comparative Example 1, which had only undergone pretreatment, showed that the particle surface was smooth, but there was obvious agglomeration. The CaSO4 sample modified with polyethylene glycol perfluoroolefin methyl ether prepared in Example 1 has good particle dispersion, clear boundaries of individual particles, and a thin coating layer different from the crystal structure of CaSO4 visible on the particle surface.

[0035] 2. Contact angle measurement The contact angle was measured using the seated drop method. When water was dropped onto the tablet of unmodified CaSO4 (Comparative Example 1), the water droplet spread out rapidly and was absorbed, exhibiting hydrophilicity. However, when dropped onto the tablet of the modified CaSO4 anti-agglomeration agent prepared in Example 1, the water droplet formed a spherical shape with a contact angle significantly greater than 90°, exhibiting hydrophobicity. When water was dropped onto the tablets of the modified CaSO4 anti-agglomeration agents prepared in Comparative Examples 2-6, the water droplet formed a spherical shape with a contact angle significantly greater than 90°, exhibiting hydrophobicity.

[0036] Table 1 Contact Angle Test Results

[0037] Experimental Example 2: Investigation of the Application of Anti-agglomeration Agents The preparation and application process of the anti-agglomeration agent of this invention is as follows: Figure 1 As shown, this experimental example aims to examine the practical application effect of anti-agglomeration agents.

[0038] (1) Preparation of hydrogen fluoride using anti-agglomeration agent This experiment was conducted in a fluidized bed reactor with a total height of 1300 mm and an inner diameter of 240 mm. The bottom of the reactor was equipped with a pore distribution plate.

[0039] The reactant gas is a mixture of SO3 and water vapor (molar ratio 4:2), with a total inlet flow rate of 120 m³. 3 After being heated to 150℃ by a preheater, the gas is introduced into the bed from the bottom at an apparent gas velocity of 0.15 m / s. The bed temperature is controlled at around 250℃ by external heating, and the bed level is kept stable through continuous monitoring and control.

[0040] 1 kg of the anti-agglomeration agent prepared in Example 1 and Comparative Examples 1-6 was mixed with 99 kg of fine fluorite powder (chemical formula CaF2, particle size 0.12 mm, moisture content 0.6%) in a double helix premixer and then added to a fluidized bed reactor to prepare hydrogen fluoride. 0.1 kg of the substance from Comparative Examples 7 and 8 was mixed with 99.9 kg of fine fluorite powder (particle size 0.12 mm, moisture content 0.6%) in a double helix premixer and then added to a fluidized bed reactor to prepare hydrogen fluoride. A blank control group was set up by directly adding 100 kg of fine fluorite powder (particle size 0.12 mm, moisture content 0.6%) to a fluidized bed reactor to prepare hydrogen fluoride.

[0041] After the reaction is complete, switch to the N2 purging system and allow it to cool naturally to below 80°C. Collect all solid residue from the discharge port.

[0042] (2) Aggregation rate analysis Solid residue is sieved using a standard sieve (5mm aperture). The material that passes through the sieve is agglomerated material, and the material that passes through the sieve is residue. The formula for calculating the agglomeration rate is: Agglomeration rate = (Total mass of agglomerates on the screen / Total mass of residue) × 100%; Formula for calculating anti-agglomeration efficiency:

[0043] In the above formula, R 0 represents the aggregation rate of the blank control group. R 1 represents the aggregation rate of the experimental group.

[0044] (3) Product purity analysis The purity of hydrogen fluoride was determined by acid-base titration: Using polyethylene glassware, a suitable amount of condensed hydrogen fluoride sample was weighed in a fume hood, dissolved in deionized water, and titrated with sodium hydroxide standard solution with phenolphthalein as an indicator until the solution turned pink and did not fade within 30 seconds. The mass fraction of hydrogen fluoride was calculated based on the volume of sodium hydroxide standard solution consumed.

[0045] Formula for calculating the purity of hydrogen fluoride:

[0046] In the above formula, W For the purity of HF, c The concentration of the sodium hydroxide standard solution is... V The volume consumed is 20.01, which is the molar mass of hydrogen fluoride. m For sample quality.

[0047] (4) Results Analysis The results of the agglomeration rate, product purity, and stable operating time of anhydrous hydrogen fluoride prepared in a fluidized bed using an anti-agglomeration agent are shown in Table 2.

[0048] Table 2 Performance indicators of anti-agglomeration agents in the preparation of hydrogen fluoride

[0049] As shown in Table 2, the blank control group and the unmodified CaSO4 group (Comparative Example 1) could not operate stably for more than 48 hours due to severe agglomeration of fluorite powder, and therefore did not have industrial feasibility. Both Comparative Example 2 (PEG-modified CaSO4) and Comparative Example 7 (direct addition of PEG) showed a significant decrease in hydrogen fluoride purity (≤99.50%) due to the thermal decomposition of PEG, which confirms that the thermal instability of PEG itself is the root cause of product contamination. Comparative Example 2 (anti-agglomeration rate 70%, running time 60h) performed better than Comparative Example 7 (anti-agglomeration rate 58%, running time 48h), demonstrating that the strategy of using CaSO4 as a carrier to fix the modifier has a synergistic effect on unstable modifiers—that is, it can effectively improve their dispersibility and persistence. However, the eventual performance degradation indicates that the thermal stability and acid stability of the modifier itself are the main bottlenecks limiting its long-term activity. The reason why Comparative Example 3 (Cl-PEG-Cl modified CaSO4) had poor results is that Cl-PEG-Cl modified CaSO4 is unstable in the reaction system and will decompose rapidly. The decomposition products may contaminate the bed material or lead to increased stickiness on the particle surface. The reason why Comparative Example 4 (PEG-Si(CH3)3 modified CaSO4) had poor results is that the Si-C bonds and ether bonds in PEG-Si(CH3)3 are easily broken under high temperature and acid conditions, and the decomposition products may contaminate the bed material or lead to increased stickiness on the particle surface. The reason why Comparative Example 5 (PFOA modified CaSO4) and Comparative Example 6 (PFOS modified CaSO4) had poor results is that they may decompose at high temperatures to produce HF or fluoride byproducts, which may interfere with the chemical equilibrium of the main reaction and even corrode the equipment. Comparative Example 8 (direct addition of polyethylene glycol perfluoroalkenyl methyl ether) was superior to Comparative Example 7, but the purity of hydrogen fluoride was lower than that of Example 1 (99.70%), and the running time was shorter (80 h). This indicates that even with pure polyethylene glycol perfluoroalkenyl methyl ether, direct addition can still lead to uneven distribution of the modifier, local overdose, or easy entrainment by the gas flow, thus affecting product purity and limiting its long-term effectiveness. Only by combining stable polyethylene glycol perfluoroalkenyl methyl ether with a CaSO4 carrier can both ultimate purity and ultra-long running time be achieved.

[0050] In summary, in the CaF2-H2SO4 reaction system for producing hydrogen fluoride, the anti-agglomeration agent of the present invention effectively prevents the agglomeration of reactants through a four-fold synergistic effect: eliminating liquid bridges through hydrophobic coating of fluorocarbon chains, isolating particles through steric hindrance, inhibiting CaSO4 crystal bridging and surface coating, and reducing interfacial tension to improve acid-mineral mixing. This ensures continuous and efficient contact and reaction between CaF2 and sulfuric acid (obtained by the reaction of sulfur trioxide and water), and effectively prevents calcium sulfate from agglomerating.

[0051] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An anti-agglomeration agent, characterized in that, Including the following raw materials: Calcium sulfate, polyethylene glycol perfluoroolefin methyl ether.

2. The anti-agglomeration agent according to claim 1, characterized in that, The anti-agglomeration agent comprises the following raw materials in parts by weight: 1000 parts by weight of calcium sulfate and 1 part by weight of polyethylene glycol perfluoroolefin methyl ether.

3. The anti-agglomeration agent according to claim 1 or 2, characterized in that, The calcium sulfate includes the byproduct calcium sulfate; And / or, the chemical formula of the polyethylene glycol perfluoroolefin methyl ether is C n F 2n-1 O(CH2CH2O) m CH3, where n is an integer from 6 to 12 and m is an integer from 4 to 24; optionally, the polyethylene glycol perfluoroolefin methyl ether is C 10 F 19 O(CH2CH2O) 22 CH3.

4. The anti-agglomeration agent according to claim 3, characterized in that, The byproduct calcium sulfate is obtained by pretreatment of the calcium sulfate crude residue produced during the production of anhydrous hydrogen fluoride. And / or, in the byproduct calcium sulfate, CaSO4 ≥ 90 wt%.

5. The anti-agglomeration agent according to claim 4, characterized in that, The pretreatment includes the following steps: take coarse calcium sulfate residue, screen it through a vibrating sieve to separate fine residue with a particle size ≤0.5mm, dry the obtained fine residue at 110~150℃ for 2~3h, and then grind it to obtain calcium sulfate by-product with a particle size of 5~20μm.

6. A method for preparing an anti-agglomeration agent according to any one of claims 1-5, characterized in that, Includes the following steps: According to the formula, polyethylene glycol perfluoroolefin methyl ether and calcium sulfate are mixed.

7. The anti-agglomeration agent according to claim 6, characterized in that, The mixing conditions are: stirring at a speed of 2500~3000 rpm and a temperature of 80~90℃ for 3~5 hours.

8. The use of the anti-agglomeration agent according to any one of claims 1-5 or the anti-agglomeration agent prepared by the preparation method according to claim 6 or 7 in the production of anhydrous hydrogen fluoride.

9. A method of applying the anti-agglomeration agent according to any one of claims 1-5 or the anti-agglomeration agent prepared by the preparation method according to claim 6 or 7, characterized in that, The process includes the following steps: mixing an anti-agglomeration agent with fluorite powder, and reacting it with sulfur trioxide and water vapor in a fluidized state to produce hydrogen fluoride.

10. The application method according to claim 9, characterized in that, The mass ratio of the anti-agglomeration agent to fluorite powder is 1:99.

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