A Nanomaterial-Based Ultrasonic-Assisted Fluorine Resource Recovery Method and Its Application in High-Value Organic Fluorine Compounds

Abstract

This invention relates to the field of fluorine resource recovery technology, and particularly to a method for fluorine resource recovery based on nanomaterials and its application in high-value organic fluorine compounds. The method includes the following steps: Step 1: After crushing and drying pretreatment of electrolyte waste residue, leaching is performed using ionic liquids and ultrasound to obtain a fluorine-containing leachate; Step 2: Fluoride ions are adsorbed from the fluorine-containing leachate using Fe3O4@C-ZrO2 nanomaterials as the solid phase via solid-phase extraction; Step 3: Fluoride ions adsorbed on the Fe3O4@C-ZrO2 nanomaterials are separated using magnetic separation technology to obtain a fluorine-containing solution; Step 4: The fluorine-containing solution is concentrated using nanofiltration to obtain a high-purity KF solution. The fluoride recovery process from electrolyte waste residue using ionic liquid-ultrasound synergistic leaching and magnetic mesoporous carbon adsorption separation achieves a fluoride purity of up to 98%, meeting the requirements for the synthesis of fluorine-containing chemicals.

Description

Technical Field

[0001] This invention relates to the field of fluorine resource recovery technology, and in particular to an ultrasonic-assisted fluorine resource recovery method based on nanomaterials and its application in high-value organic fluorine compounds. Background Technology

[0002] Currently, the aluminum smelting industry mainly uses the Hall-Héroult process, which uses alumina as raw material and cryolite as solvent for electrolysis. Due to the low grade of bauxite and its high lithium salt content, lithium salts can enter the product during alumina preparation, leading to an increase in the lithium content of the alumina used for electrolysis. During electrolysis, lithium oxide reacts with cryolite to form lithium fluoride, which accumulates continuously with the extension of the electrolytic cell's service life, reaching a mass fraction of 3%–7%. Excessive lithium fluoride leads to a significant decrease in the initial crystallization temperature of the electrolyte, reduced alumina solubility, and increased sediment at the bottom of the cell, thereby deteriorating the electrolysis process, reducing current efficiency, and increasing energy consumption.

[0003] To address this issue, electrolytic aluminum companies typically extract high-lithium electrolytes periodically and replace them with new low-lithium electrolytes. The extracted lithium-containing waste electrolytes are often disposed of as solid waste, and their production is increasing year by year, containing large amounts of fluorides such as Na3AlF6 and NaF. Therefore, developing efficient recycling and treatment technologies for fluorinated aluminum electrolytes has become crucial for promoting the green development of the industry.

[0004] Currently, the resource utilization of electrolyte waste mainly focuses on lithium recovery, such as the preparation of lithium carbonate or lithium hydroxide, while research on the high-value utilization of fluorine resources is relatively limited.

[0005] The existing technologies for utilizing fluorine resources in aluminum electrolytes mainly include: (1) Wet process; This process uses strong acids (HCl, HNO3, etc.), strong alkalis (NaOH) or salts (CaCl2) to leach the soluble and insoluble components in the waste electrolyte and treat fluorides and cyanides. Through acid leaching, alkali leaching or combined alkali and acid leaching, harmful gases such as HCN can be avoided from escaping, and fluorides (NaF, AlF3, CaF2, Na3AlF6, etc.) can be introduced into the solution. Then, CaO is added to adjust the pH to >5, and CaF2 is precipitated. This method is technically mature, but the added value of the product CaF2 is low and the economic benefits are poor. (2) Pyrometallurgical roasting process; This process uses CaCO3, CaO or SiO2-containing materials as additives and bituminous coal as fuel to roast the waste electrolyte in a rotary kiln. The roasting flue gas has a similar composition to the aluminum electrolysis flue gas, containing a variety of fluorides (NaF, AlF3, CaF2, Na3AlF6, Na5Al3F6, etc.). 14(etc.), which need to be treated by alumina adsorption and lime water rinsing. The final fluoride composition is complex and difficult to realize high-value utilization as a chemical. (3) Combined treatment process; Combined processes such as roasting-leaching are gradually gaining attention, which can alleviate the shortcomings of single wet or pyrometallurgical processes to a certain extent and realize the harmlessness and resource utilization of waste residue.

[0006] However, current research focuses on improving lithium recovery rates, while the utilization of fluorine resources is still in its early stages. Summary of the Invention

[0007] The purpose of this invention is to provide a method for ultrasonic-assisted fluorine resource recovery based on nanomaterials and its application in high-value organofluorine compounds. This method utilizes an ionic liquid-ultrasonic assisted leaching process and a magnetic mesoporous carbon adsorption separation process to recover fluorides from electrolyte waste residue. The purity of the fluorides is as high as 98%, which can meet the needs of fluorine-containing chemical synthesis.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The ultrasonic-assisted fluorine resource recovery method based on nanomaterials includes the following steps:

[0010] Step 1: After crushing and drying the electrolyte waste residue, leaching is enhanced by ionic liquid and ultrasound to obtain fluorine-containing leachate.

[0011] The ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate, and its solid-liquid ratio with the electrolyte waste residue is 1:(5-10); the ultrasonic power is 8~12W / cm. 3 , frequency 40±2kHz;

[0012] Step 2: Using solid-phase extraction technology, Fe3O4@C-ZrO2 nanomaterials are used as the solid phase to adsorb fluoride ions from the fluoride-containing leachate;

[0013] The Fe3O4@C-ZrO2 nanomaterials were prepared by a layer-by-layer modification method: First, a carbon layer was coated on the surface of the Fe3O4 magnetic core to form a Fe3O4@C core-shell structure; then, FeZrO2 nanoparticles were loaded on the surface of the carbon layer to form magnetically recyclable Fe3O4@C-ZrO2 nanomaterials.

[0014] Step 3: Based on magnetic separation technology, fluoride ions adsorbed on Fe3O4@C-ZrO2 nanomaterials are separated to obtain a fluoride-containing solution;

[0015] Step 4: Concentrate the fluoride-containing solution using nanofiltration technology to obtain a high-purity KF solution.

[0016] This invention proposes a highly efficient method for recovering fluorine resources that combines ionic liquid-ultrasound synergistic leaching with magnetic mesoporous carbon-nanofiltration gradient purification; it has the following beneficial effects:

[0017] Leaching stage: [Bmim][BF4] ionic liquid is used, whose anion is BF4 - Can be used with F - Formation of stable [BF4-nF n ] （n-1）- The ultrasound creates complexes, thus promoting the dissociation of fluorides. Simultaneously, the cavitation effect of the ultrasound generates localized high temperatures and pressures, effectively disrupting the crystal structure of stable fluorides. The synergistic effect of these two factors significantly improves the fluoride leaching efficiency, achieving a leaching rate of over 93%.

[0018] Purification stage: First, preliminary separation is performed using the magnetic mesoporous carbon adsorbent Fe3O4@C-ZrO2. The ZrO2 surface can efficiently adsorb F through coordination exchange. - The internal Fe3O4 magnetic core facilitates rapid separation and regeneration of the adsorbent under the influence of an external magnetic field. Subsequently, deep purification is performed using an NF270 nanofiltration membrane, which is effective for monovalent ions (such as K+). + F - It has a low rejection rate, which can effectively separate fluorine from polyvalent impurities.

[0019] The present invention also provides a method for synthesizing high-value organofluorine compounds, comprising: using the KF solution recovered by the above method as raw material, performing an electrochemical fluorination-sulfonation reaction in a dual-chamber electrolytic cell to synthesize high-value-added fluorinated chemicals; wherein the high-value-added fluorinated chemicals include, but are not limited to, p-trifluoromethylbenzenesulfonic acid or perfluorobutylsulfonic acid.

[0020] This invention relates to an electrochemical fluorination-sulfonation coupled synthesis method. The process is carried out in a two-chamber electrolyzer using a Nafion® 117 membrane as the diaphragm, Pt / Ti as the anode, and Ni-Mo as the cathode. The anolyte is a 1.5M KF-acetonitrile solution containing 0.3M styrene, and the catholyte is a 1.0M KF-DMF solution. The electrolysis temperature is 15.0 mA / cm². 2 The reaction was carried out at a current density of -10°C at the anode and 25°C at the cathode for 8.2 hours. The reaction product was separated and purified by vacuum distillation, ether extraction and silica gel column chromatography to finally obtain high-purity, high-value-added fluorine-containing chemicals.

[0021] The advantages of the method of this invention in the recovery and high-value utilization of fluorine resources realize the green transformation of the entire process from waste residue to high-value-added fluorine-containing chemicals. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0023] Figure 2 This is a graph showing the ion chromatography detection results of KF solution obtained in this invention.

[0024] Figure 3 This is a schematic diagram of the nitrogen adsorption-desorption isotherm of the Fe3O4@C-ZrO2 nanomaterial of this invention.

[0025] Figure 4 This is a pore size distribution diagram of the Fe3O4@C-ZrO2 nanomaterial of the present invention. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example

[0027] This embodiment provides a Fe3O4@C-ZrO2 nanomaterial, the preparation method of which includes:

[0028] Step 1: Preparation of Fe3O4 magnetic cores based on coprecipitation method;

[0029] 5.4 g of FeCl3·6H2O and 2.0 g of FeCl2·4H2O were dissolved in 100 mL of deionized water and stirred for 30 min under nitrogen protection. The temperature was raised to 80°C, and 10 mL of 25% NH4OH solution was added dropwise. The reaction was allowed to proceed for 30 min. The black precipitate was collected by magnetic separation, washed with deionized water until neutral, and dried under vacuum at 60°C for 12 h to obtain Fe3O4 nanoparticles.

[0030] Step 2: Preparation of Fe3O4@C core-shell structure based on glucose hydrothermal carbonization;

[0031] 1.0 g of Fe3O4 nanoparticles prepared in step 1 were dispersed in 80 mL of 0.5 M glucose solution and sonicated for 30 min. The mixture was then transferred to a 100 mL reactor and reacted at 180°C for 6 h. After cooling, the nanoparticles were magnetically separated, washed three times with ethanol, and vacuum dried at 60°C for 12 h to obtain the Fe3O4@C core-shell structure.

[0032] Step 3: Preparation of Fe3O4@C-ZrO2 nanomaterials based on the sol-gel method;

[0033] 0.5 g of Fe3O4@C from step 2 was dispersed in 50 mL of ethanol, and 1.0 g of ZrOCl2·8H2O and 0.5 g of urea were added. The mixture was refluxed at 80°C for 4 h. The solid was collected by centrifugation, washed three times with ethanol, and dried under vacuum at 60°C for 12 h. The solid was then calcined at 400°C for 2 h under a nitrogen atmosphere with a heating rate of 2°C / min to obtain Fe3O4@C-ZrO2 nanomaterials.

[0034] Using BET nitrogen adsorption, such as Figure 3 As shown, the nitrogen adsorption-desorption isotherm of the Fe3O4@C-ZrO2 composite material was measured at 77 K (liquid nitrogen temperature). From the figure, it can be seen that BET SSA = 420m. 2 / g indicates that the introduction of carbon support (C) and ZrO2 effectively suppressed the aggregation of Fe3O4 nanoparticles and maintained a high surface area. The pore size was measured using the BJH method, such as... Figure 4 As shown, the BJH pore size distribution of the Fe3O4@C-ZrO2 composite material (Barrett–Joyner–Halenda method, calculated based on nitrogen desorption branch data) shows that the material has a typical mesoporous structure (2~8 nm) and a wide pore size distribution, making it suitable for catalysis, adsorption or loading of nanoparticles, which is highly consistent with previous BET results. Example

[0035] like Figure 1 As shown, this embodiment provides an ultrasonic-assisted fluorine resource recovery method based on nanomaterials, including the following steps:

[0036] Step 1: First, crush the electrolyte waste residue to a particle size of less than 100μm, and then dry it to a moisture content of less than 2%; based on the synergistic enhancement of leaching by ionic liquid and ultrasound, a fluorine-containing leachate is obtained.

[0037] The ionic liquid is selected as 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4]; the anion BF4 - Can be used with F - Formation of stable [BF4-nF n ] （n-1）- Complexes, enabling the solid-state F - With BF4 in ionic liquids - An exchange reaction occurs, causing F - The mixture is introduced into the liquid phase, where the solid-liquid ratio of the ionic liquid to the electrolyte waste residue is 1:(5-10). After thoroughly mixing the ionic liquid and electrolyte waste residue, it is placed in an ultrasonic reactor, and the ultrasonic process is initiated with a power of 8-12 W / cm². 3 The cavitation effect intensity and fluorine leaching rate are both optimal.

[0038] After the leaching reaction is completed, the waste residue is transferred to a centrifuge and the speed is controlled at 8000 rpm; the centrifugation time is 10 min to obtain fluorine-containing leachate and residue.

[0039] Step 2: Using solid-phase extraction technology, fluoride ions are adsorbed from the fluoride-containing leachate using the Fe3O4@C-ZrO2 nanomaterials prepared in Example 1 as the solid phase; the specific steps include:

[0040] S2-1: Fe3O4@C-ZrO2 nanomaterials were packed into a column using a wet packing method to form a Fe3O4@C-ZrO2 adsorption column; the Fe3O4@C-ZrO2 adsorption column was wetted with a 0.1M HNO3 solution until neutral, and nitrogen gas was used to purge the column to remove air bubbles.

[0041] S2-2: Adjust the pH of the fluoride-containing leachate to 6.5 ± 0.2 using a 0.1 M HCl solution; the amount of HCl solution added, V = (pH... in -pH ta )×V sa / k; pH in The initial pH value of the fluoride leachate; pH ta The target pH value for the fluoride-containing leachate is 6.5 ± 0.2; V sa is the volume of the fluoride leachate; k is the empirical coefficient of buffer capacity, which is set to a fixed value of 2.5.

[0042] S2-3: The pH-adjusted fluoride-containing leachate is loaded onto the column for dynamic adsorption; the flow rate is 2 BV / h. Coordination exchange occurs on the ZrO2 surface, and fluoride ions are adsorbed onto the adsorbent surface. Adsorption stops when the fluoride ion concentration in the effluent exceeds 1800 ppm (at which point the control is set at the inlet concentration of 10%).

[0043] Step 3: Based on magnetic separation technology, fluoride ions adsorbed in Fe3O4@C-ZrO2 nanomaterials are separated to obtain a fluoride-containing solution.

[0044] In a permanent magnet separator containing Fe3O4@C-ZrO2 nanomaterials adsorbed with fluoride ions, magnetic separation was performed under a magnetic field strength of 0.5T. Desorption liquid was added to the solid phase obtained after magnetic separation, and the mixture was treated at 150 rpm for 30 min. Solid-liquid separation was then performed again under a 0.5T magnetic field strength. The solid phase was washed three times with deionized water, vacuum filtered, and the pH of the filtrate was measured. This washing process was repeated multiple times until the pH of the filtrate reached 7.0 ± 0.5. The filtrate from the separation process was collected as a high-concentration fluoride-containing solution.

[0045] Step 4: Concentrate the fluoride-containing solution using nanofiltration technology to obtain a high-purity KF solution.

[0046] Add 0.1 mM Na4EDTA as an anti-scaling agent to the high-concentration fluorine-containing solution, filter through a 0.45 μm microfiltration membrane, then rinse under low pressure of 0.2 MPa for 5 min, and then increase the pressure to 1.0 MPa at a rate of 0.1 MPa / min; circulate and concentrate to 20% of the original volume to obtain a high-purity KF solution.

[0047] Method for restoring flux of contaminated microfiltration membranes: First, wash with a mixture of 0.1% NaOH and 0.03% SDS at 40℃ for 30 min, followed by acid washing with 0.2% citric acid solution at 30℃ for 20 min. After two stages of cleaning, the membrane flux recovery rate is increased to over 95%, and it can be reused. Example

[0048] This embodiment provides a method for synthesizing high-value organofluorine compounds. The method uses the KF solution recovered in Example 2 as raw material and carries out an electrochemical fluorination-sulfonation reaction in a dual-chamber electrolytic cell to synthesize high-value-added fluorinated chemicals.

[0049] The effectiveness of this invention will be verified by taking the overhaul slag from an aluminum electrolysis plant as an example.

[0050] (1) Take 100 kg of aluminum electrolyte overhaul slag. Its composition (wt%) is as follows: K 1.8%, Li 0.7%, F 12.5%, Ca 0.3%, SO4 3.2%, Mg 0.2%, PO4 1.1%, Fe 0.05%, Cl 0.8%, and moisture 18%. After crushing the slag with a jaw crusher, it is ground with a ball mill until the particle size is less than 100 μm. Then it is placed in a 105℃ forced-air drying oven and dried for 12 hours until the moisture content is less than 2%.

[0051] (2) Ionic liquid-ultrasonic synergistic leaching: 10 kg of dried waste residue was added to a stainless steel reactor, along with 50 L of 1.8 M ionic liquid [Bmim][BF4] (1-butyl-3-methylimidazolium tetrafluoroborate), with a solid-liquid ratio of 1:5 (w / v). The stirring device was turned on and stirred at 200 rpm for 10 minutes to ensure thorough mixing of the waste residue and ionic liquid. Subsequently, the ultrasonic generator was turned on, using a 1.2 cm diameter titanium alloy probe (with an effective area of ​​1.13 cm²). 2 The insertion depth was 6cm, resulting in a length of approximately 6.78cm. 3 The effective volume was set at a frequency of 40kHz and a power of 85W (power density of 12.5 W / cm³). 3 ( ), and continuously immerse for 50 minutes under a constant temperature water bath at 70℃.

[0052] After the leaching reaction was completed, the mixture was transferred to a centrifuge and centrifuged at 8000 rpm for 10 minutes to separate 45.2 L of leachate and 8.3 kg of residue. The fluoride ion concentration in the leachate and residue was measured separately. The results showed that the fluoride ion concentration in the leachate was 18500 ppm, and the residual fluoride content in the residue was 0.42 wt%, resulting in a calculated fluoride leaching rate of 93.1%.

[0053] (3) Magnetic mesoporous carbon-nanofiltration gradient purification: Take 20L of leachate, the initial pH is detected to be 8.7, add 0.1M HCl in a volume of 17600mL; add 0.1M HCl slowly at a rate not exceeding 5mL / min, while monitoring the pH value in real time, and stop adding acid immediately when the pH drops to 6.5. Finally, 19.8L of pretreated leachate with pH 6.48 is obtained. Dynamic adsorption: adsorption is stopped when the fluoride ion concentration in the effluent reaches 1850ppm (inlet concentration 10%), and a total of 15.6L of leachate is treated. Magnetic separation and nanofiltration concentration are performed to obtain 3.2L of high-purity KF solution.

[0054] The KF solution was detected by ion chromatography under the following conditions: column: Dionex IonPac AS19 (4×250mm); eluent: KOH gradient 10-50mM; flow rate: 1.0mL / min. The results are as follows: Figure 2 Therefore; according to the area normalization method, F - The concentration was 98.92%. After vacuum concentration, 2.1 kg of white KF crystals were obtained.

[0055] The 8.3 kg residue obtained from centrifugation was combined with the ionic liquid [Bmim][BF4] mixture, and 46.8 L of ionic liquid was recovered by rotary evaporation (60℃, 0.08 MPa), with a recovery rate of 93.6%. The performance indicators of the recovered ionic liquid were tested and found to be no significant difference from those of the new ionic liquid, indicating that it can be recycled.

[0056] p-Trifluoromethylbenzenesulfonic acid was prepared from the above KF solution using an electrolytic cell configured as follows: dual chamber, Nafion® 117 diaphragm, Pt / Ti anode, Ni-Mo cathode. Electrolyte: 1.5M KF-acetonitrile + 0.3M styrene at the anode, 1.0M KF-DMF at the cathode. Reaction conditions: 15.0 mA / cm², anode -10℃, cathode 25℃, reaction time 8.2 h. Product separation and purification: vacuum distillation, ether extraction, silica gel column chromatography; yielded 18.7 g of white solid p-trifluoromethylbenzenesulfonic acid.

[0057] HPLC analysis showed that the product purity was 95.2%, and the calculated molar yield was 78.5%. Compared with the traditional Simons ECF method, this embodiment avoids the use of highly toxic anhydrous HF, and the content of branched isomers in the product is less than 5%, which is significantly better than the traditional method (30-40%).

[0058] Perfluorobutylsulfonic acid was prepared by recovering potassium fluoride (KF). HPLC analysis (chromatographic conditions: C18 column, mobile phase: methanol / water = 85:15, flow rate 1.0 mL / min, detection wavelength 210 nm) showed a product purity of 96.2% and a calculated molar yield of 80.1%.

[0059] The prepared perfluorobutyl sulfonic acid was formulated into a 0.1 wt% aqueous solution, and its surface tension was tested to be 18.7 mN / m, with a contact angle of 112°, indicating excellent surface activity. Compared with commercially available perfluorooctyl sulfonic acid (PFOS), its biodegradability is improved by 3.2 times, meeting the EPA requirements for environmentally friendly fluorinated surfactants, and is suitable for applications such as fire-fighting foams and coating additives.

[0060] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for ultrasonic-assisted fluorine resource recovery based on nanomaterials, characterized in that, Includes the following steps: Step 1: After crushing and drying the electrolyte waste residue, leaching is enhanced by ionic liquid and ultrasound to obtain fluorine-containing leachate. The ionic liquid is 1-butyl-3-methylimidazolium tetrafluoroborate, and its solid-liquid ratio with electrolyte waste residue is 1:(5-10); the ultrasonic power is 8~12W / cm³, and the frequency is 40±2kHz. Step 2: Using solid-phase extraction technology, Fe3O4@C-ZrO2 nanomaterials are used as the solid phase to adsorb fluoride ions from the fluoride-containing leachate; The Fe3O4@C-ZrO2 nanomaterials were prepared by a layer-by-layer modification method: First, a carbon layer was coated on the surface of the Fe3O4 magnetic core to form a Fe3O4@C core-shell structure; then, ZrO2 nanoparticles were loaded on the surface of the carbon layer to form magnetically recyclable Fe3O4@C-ZrO2 nanomaterials. Step 3: Based on magnetic separation technology, fluoride ions adsorbed on Fe3O4@C-ZrO2 nanomaterials are separated to obtain a fluoride-containing solution; Step 4: Concentrate the fluoride-containing solution using nanofiltration technology to obtain a high-purity KF solution; The preparation method of Fe3O4@C-ZrO2 nanomaterials in step 2 includes: (1) Preparation of Fe3O4 magnetic cores based on coprecipitation method; Fe in a molar ratio of 2:1 3+ / Fe 2+ Fe3O4 nanoparticles were prepared by precipitation with NH4OH solution under nitrogen protection and at 80°C, followed by washing and drying; the precursors were FeCl3·6H2O and FeCl2·4H2O. (2) Preparation of Fe3O4@C core-shell structure based on glucose hydrothermal carbonization; Using the Fe3O4 nanoparticles as the magnetic core and glucose as the carbon source, a carbon layer was coated on the surface of the nanoparticles by hydrothermal method. After cooling, the nanoparticles were magnetically separated, washed, and dried to obtain the Fe3O4@C core-shell structure. (3) Preparation of Fe3O4@C-ZrO2 nanomaterials; The Fe3O4@C core-shell structure, ZrOCl2·8H2O, and urea were refluxed in ethanol at 80°C for 4 hours. After centrifugation, washing, and drying, the mixture was calcined in nitrogen at 400°C for 2 hours to crystallize ZrO2, ultimately obtaining magnetically recyclable Fe3O4@C-ZrO2 nanomaterials. The mass ratio of Fe3O4@C core-shell structure, ZrOCl2·8H2O, and urea was 1:2:

1.

2. The ultrasonic-assisted fluorine resource recovery method based on nanomaterials according to claim 1, characterized in that, In step 1, the electrolyte waste residue is crushed to a particle size of less than 100 μm and dried to a moisture content of less than 2%.

3. The ultrasonic-assisted fluorine resource recovery method based on nanomaterials according to claim 1, characterized in that, Step 2 involves separating fluoride ions from the fluoride-containing leachate using Fe3O4@C-ZrO2 nanomaterials and column chromatography, including: Step 2-1: The Fe3O4@C-ZrO2 nanomaterials were packed into a column using a wet packing method to form a Fe3O4@C-ZrO2 adsorption column; the Fe3O4@C-ZrO2 adsorption column was wetted with a 0.1M HNO3 solution until neutral, and nitrogen gas was used to purge the column to remove air bubbles; Step 2-2: Adjust the pH of the fluoride-containing leachate to 6.5 ± 0.2 using a 0.1 M HCl solution; Steps 2-3: The fluoride-containing leachate with adjusted pH value is loaded onto the column for dynamic adsorption; coordination exchange occurs on the ZrO2 surface, and fluoride ions are adsorbed on the surface of the adsorbent.

4. The ultrasonic-assisted fluorine resource recovery method based on nanomaterials according to claim 1, characterized in that, In step 3, fluoride ions adsorbed on the Fe3O4@C-ZrO2 nanomaterials are separated using magnetic separation technology to obtain a fluoride-containing solution, including: First, solid-liquid separation was performed using a magnetic field strength of 0.5T. Then, desorption liquid was added to the separated Fe3O4@C-ZrO2 nanomaterials, and the mixture was shaken. Solid-liquid separation was then performed again using a magnetic field strength of 0.5T. The filtrate after the two separations was collected, which is the fluorine-containing solution. The desorption solution is a mixed solution of 0.2M NaOH and 0.05M EDTA.

5. The ultrasonic-assisted fluorine resource recovery method based on nanomaterials according to claim 1, characterized in that, In step 4, nanofiltration concentration is achieved using an NF270 nanofiltration membrane. First, the membrane is flushed under low pressure of 0.2 MPa, then pressurized to 1.0 MPa at a rate of 0.1 MPa / min; the concentration is then circulated and reduced to 20% of the original volume. Flux recovery of NF270 nanofiltration membrane: First, it is washed with an alkaline solution of 0.1% NaOH and 0.03% SDS, followed by acid washing with a 0.2% citric acid solution.

6. A method for synthesizing high-value organofluorine compounds, characterized in that, include: Using the KF solution recovered by the method described in any one of claims 1 to 5 as raw material, an electrochemical fluorination-sulfonation reaction is carried out in a dual-chamber electrolytic cell to synthesize high-value organic fluorine compounds.

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