A method for purifying and recovering hydrofluoric acid waste liquid in the electronics industry

Abstract

The invention discloses a method for purifying and recovering hydrofluoric acid waste liquid in the electronics industry, comprising: firstly distilling the hydrofluoric acid waste liquid to remove water, then performing membrane separation treatment on the feed liquid to remove most of the metal ions in the feed liquid, then performing adsorption treatment on the feed liquid to remove a small amount of metal ions in the feed liquid, and finally performing membrane separation treatment to remove trace metal ions and particulate impurities in the feed liquid. This patent effectively removes impurities and metal ions in hydrofluoric acid waste liquid in the electronics industry through a specific combined process, and makes the product meet the electronic grade reuse standard, thereby improving the resource recovery rate.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-clean and high-purity chemistry, and in particular relates to a method for purifying and recovering hydrofluoric acid waste liquid in the electronics industry. Background Art

[0002] In the electronics industry, hydrofluoric acid (HF) is a key cleaning agent widely used in the cleaning of semiconductor manufacturing and integrated circuits. However, the used hydrofluoric acid waste liquid contains a large amount of water, a small amount of hydrofluoric acid, particulate impurities and metal ions, which seriously affect the reuse value and safety of hydrofluoric acid. Therefore, the development of an effective method for purifying and recovering hydrofluoric acid waste liquid is of great significance for resource recycling and environmental protection.

[0003] Existing hydrofluoric acid purification and recovery technologies mainly include chemical precipitation, ion exchange and distillation. The chemical precipitation method converts impurities in the solution into insoluble solids by adding a precipitant, and then separates them by filtration, but this method will produce a large amount of fluorine-containing sludge, which has a complex composition and low quality. It cannot be recycled and there is a secondary pollution problem. The ion exchange method uses ion exchange resins to adsorb impurity ions in the solution, but the regeneration and treatment costs of the resin are high, and the efficiency is limited when treating high-concentration waste liquids. The distillation method evaporates the hydrofluoric acid by heating, and then collects the purified hydrofluoric acid by condensation, but the high temperature during the distillation process may cause corrosion to the equipment and the energy consumption is high.

[0004] Although the existing technology can purify hydrofluoric acid to a certain extent, there are still some limitations, such as low purification efficiency, high cost, equipment corrosion problems, and inability to effectively remove certain types of impurities. Especially in the electronics industry, the purity requirements for hydrofluoric acid are extremely high, and the existing purification technology is often difficult to meet the reuse standards of electronic-grade hydrofluoric acid. Therefore, it is urgent to develop more effective and environmentally friendly hydrofluoric acid waste liquid recycling technology to reduce environmental pollution, reduce production costs, and improve the recycling rate of resources. Summary of the invention

[0005] The purpose of the present invention is to provide an innovative method for purifying and recovering hydrofluoric acid waste liquid in the electronics industry. The present invention effectively removes moisture, impurities and metal ions in hydrofluoric acid waste liquid through a series of optimized process steps and purification methods, improves the purity of hydrofluoric acid, makes it reach the electronic grade reuse standard, reduces energy consumption and the risk of equipment corrosion, and improves the resource recovery rate.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for purifying and recovering hydrofluoric acid waste liquid in the electronics industry comprises the following steps:

[0008] (1) The hydrofluoric acid waste liquid is sent to a distillation tower, and nitrogen is charged into the distillation tower for distillation treatment. The top temperature of the distillation tower is 60°C to 100°C, the bottom temperature is 70°C to 110°C, and the operating pressure is controlled to be 0.02 to 0.1 MPa; the inner wall of the distillation tower has an anti-corrosion layer;

[0009] (2) sending the side-line fraction of the distillation tower to a first membrane separation system for membrane separation treatment, wherein the membrane material of the first membrane separation system is an acid-resistant membrane;

[0010] (3) sending the permeate obtained by the first membrane separation system to an adsorption tower for adsorption treatment to remove some metal ions in the feed liquid; the inner wall of the adsorption tower is provided with an anti-corrosion material layer;

[0011] (4) The feed liquid treated by the adsorption tower is sent to a second membrane separation system for membrane separation treatment. The membrane material of the second membrane separation system is an acid-resistant metal ion removal membrane, which further removes trace metal ions and particulate impurities in the feed liquid and obtains electronic grade hydrofluoric acid on the permeate side of the second membrane separation system.

[0012] Preferably, the reflux ratio of the distillation tower in step (1) is 0.1-1.

[0013] Preferably, the nitrogen filling rate in step (1) is 0.1~1Nm 3 / h.

[0014] Preferably, the anti-corrosion layer in step (1) is a polytetrafluoroethylene (PTFE) layer or a PFA layer.

[0015] Preferably, step (1) further comprises the step of extracting water from the top of the distillation tower.

[0016] Preferably, the acid-resistant film in step (2) is a composite film material of one or more of polyamide (PA), polysulfonamide (PSA) or polyethyleneimine (PEI). The acid-resistant film can be prepared by any one of interfacial polymerization, phase inversion or surface modification.

[0017] Preferably, the first membrane separation system described in step (2) comprises a plurality of groups of acid-resistant membrane modules connected in series or in parallel, and the inner lining of the acid-resistant membrane modules is PFA or polytetrafluoroethylene (PTFE) resin.

[0018] Preferably, the anti-corrosion material layer in step (3) is PTFE or PFA.

[0019] Preferably, the adsorption tower in step (3) is filled with an acid-resistant chelating resin as an adsorbent, and the filling height of the adsorbent accounts for 1 / 3 to 1 / 2 of the height of the adsorption tower.

[0020] Preferably, the acid-resistant chelating resin is a PHA chelating resin.

[0021] More preferably, the PHA chelating resin is prepared by the following method:

[0022] (1-1) sodium persulfate is added as a thermal initiator to a mixed aqueous solution of acrylamide and N,N-methylenebisacrylamide, and the mixture is heated in a water bath at 60°C for 15 to 30 min to initiate a polymerization reaction to obtain a polymer;

[0023] (1-2) The polymer is placed in a hydroxylamine hydrochloride solution for 30 minutes to form hydroxamic acid groups; then the pH is adjusted to 12 with a sodium hydroxide solution, the mixture is left overnight and neutralized with an acid, and then washed to obtain the PHA chelating resin.

[0024] Preferably, the mass ratio of acrylamide to N,N-methylene-bisacrylamide is 5:1.

[0025] Preferably, the PHA chelating resin is pretreated before use, and the pretreatment includes:

[0026] The PHA chelating resin is soaked in water for 1-1.5 hours, and then washed alternately with 4%-6%wt H2SO4, water, and 4%-6%wt NaOH for 3-5 times, and finally washed with water until neutral.

[0027] Preferably, the second membrane separation system described in step (4) comprises a plurality of groups of acid-resistant metal ion removal membrane modules connected in series or in parallel, and the membrane material of the acid-resistant metal ion removal membrane module is a perfluoro PMMD-CTFE membrane material, which can further remove trace metal ions and particulate impurities in the hydrofluoric acid waste liquid.

[0028] The perfluorinated PMMD-CTFE membrane material is prepared by the following method:

[0029] (2-1) Preparation of copolymer A:

[0030] Perfluoro-2-methylene-4-methyl-1,3-dioxolane (PMMD) and chlorotrifluoroethylene (CTFE) are mixed in a perfluoro solvent and polymerized under the action of a catalyst to obtain a copolymer A;

[0031] (2-2) Preparation of acid-resistant composite film:

[0032] The copolymer A and acetone are mixed in a perfluorinated solvent at 60-80° C. to obtain a composite layer membrane liquid, and then the composite layer membrane liquid is coated on the surface of a polytetrafluoroethylene-based membrane, and dried to obtain the acid-resistant composite membrane.

[0033] Preferably, the perfluoro solvent is selected from one or more of Fluorinert FC-40, Fluorinert FC-72 or Fluorinert FC-75.

[0034] Preferably, the mass ratio of the perfluoro-2-methylene-4-methyl-1,3-dioxolane to the chlorotrifluoroethylene in step (2-1) is 1:5-7.

[0035] Preferably, in step (2-1), the total mass concentration of perfluoro-2-methylene-4-methyl-1,3-dioxolane and chlorotrifluoroethylene in the perfluoro solvent is 30% to 40%.

[0036] Preferably, the mixing in step (2-1) is carried out at 40-65°C.

[0037] Preferably, the catalyst in step (2-1) is perfluoropropionyl peroxide.

[0038] Preferably, the amount of the catalyst added in step (2-1) is 0.01% to 0.02% of the mass of the perfluoro-2-methylene-4-methyl-1,3-dioxolane.

[0039] Preferably, step (2-1) further comprises a step of removing the solvent after the polymerization reaction.

[0040] Preferably, in step (2-2), the mass concentration of the copolymer A in the composite layer membrane solution is 0.05% to 0.2%.

[0041] Preferably, the amount of acetone added in step (2-2) is 2.5% of the mass of the perfluoro solvent.

[0042] Preferably, the polytetrafluoroethylene-based membrane in step (2-2) is prepared by hot pressing polyphenylene sulfide (PPS) non-woven fabric and polytetrafluoroethylene (PTFE).

[0043] Preferably, the pore size of the basement membrane described in step (2-2) is 10-15 nm.

[0044] Compared with the prior art, the advantages of the present invention are:

[0045] (1) The present invention proposes a multi-step concentration and purification method combining distillation, adsorption and membrane separation. The water evaporated by the distillation process can be collected and reused as electronic grade ultrapure water. The metal ions and particulate impurities in the hydrofluoric acid waste liquid can be effectively removed by using the adsorption and membrane separation system, and finally the purpose of recycling electronic grade hydrofluoric acid is achieved.

[0046] (2) In the present invention, the concentration efficiency and product quality are ensured by precisely controlling the operating parameters of the distillation tower, including the tower top temperature, tower bottom temperature, operating pressure, reflux ratio and nitrogen charging rate.

[0047] (3) The membrane material used in the first membrane separation system of the present invention has excellent chemical stability and corrosion resistance. For example, the polysulfonamide membrane has a strong conjugation effect in its molecular structure, which makes it less susceptible to proton attack, and thus exhibits excellent acid resistance, making it more suitable for treating waste liquid containing hydrofluoric acid. In addition, the pore size screening and surface chemical properties of the membrane can be used to remove metal ions: for example, the polyamide membrane forms a coordination bond with the metal ions through the polyamide group to achieve the adsorption and removal of metal ions, and the polyethyleneimine membrane can achieve the effective removal of metal ions through electrostatic and coordination effects.

[0048] (4) The adsorption tower of the present invention is filled with PHA chelating resin as an adsorbent. PHA resin has good acid resistance. In addition, the -N(OH)-CO- double ligand of hydroxamic acid contains two atoms N and O with lone pair electrons. The positions of these two atoms are adjacent, so that hydroxamic acid has a strong chelating effect on many metal ions. Chelation can form stable four-membered ring and five-membered ring compounds, so it can effectively remove metal ions such as Ni in hydrofluoric acid waste liquid. 2+ , Pb 2+ 、Zn 2+ wait.

[0049] (5) In the second membrane separation system of the present invention, trace metal ions in hydrofluoric acid are further removed by the acid-resistant PMMD-CTFE perfluoro membrane material, thereby improving the purity of the product and achieving the purpose of recycling electronic-grade hydrofluoric acid; the PMMD-CTFE membrane material not only has excellent mechanical properties and chemical stability, but also the dissolution rate of the membrane material is controlled at an extremely low level of less than 10 ppt, and the total organic carbon content is less than 0.1 ppt, thereby avoiding the potential impact of membrane material dissolution on product purity. In addition, it can also remove possible trace particulate impurities in the adsorption process, thereby ensuring the purity and reliability of the final product.

[0050] (6) The distillation device, adsorption tower and membrane assembly in the present invention all adopt a corrosion-resistant inner layer structure. Through special material selection and process design, not only the durability and corrosion resistance of the equipment are improved, but also the efficiency and feasibility of the entire process method in treating hydrofluoric acid waste liquid are ensured, providing an innovative, environmentally friendly and economical solution for the purification and recovery of waste acid in the electronics industry. DETAILED DESCRIPTION

[0051] Example 1

[0052] (1) Preparation of PHA chelating resin:

[0053] (1-1) Add 2 g of sodium persulfate as a thermal initiator to a mixed aqueous solution (500 mL) of 100 g of acrylamide and 20 g of N,N-methylenebisacrylamide, and heat in a 60° C. water bath for 15 to 30 min to initiate a polymerization reaction to obtain a polymer;

[0054] (1-2) The polymer is crushed and washed, and then placed in a 0.5 M hydroxylamine hydrochloride solution for 30 minutes to form hydroxamic acid groups; the pH is then adjusted to 12 with a 1 M sodium hydroxide solution, the mixture is left overnight and neutralized with 3 M hydrochloric acid, and then washed to obtain the PHA chelating resin.

[0055] (1-3) Soak the PHA chelating resin in deionized water for 1 to 1.5 hours. Wash the resin with 4% to 6% wt H2SO4, deionized water, and 4% to 6% wt NaOH alternately for 3 to 5 times. Finally, wash it with deionized water until it is neutral. After drying, fill it into the adsorption tower. The filling height is 1 / 3 to 1 / 2 of the height of the adsorption tower.

[0056] (2) Preparation of PMMD-CTFE membrane materials:

[0057] Perfluoro-2-methylene-4-methyl-1,3-dioxolane and chlorotrifluoroethylene are added to a perfluoro solvent in a mass ratio of 1:6. The perfluoro solvent used is Fluorinert FC-72, and the total mass concentration of perfluoro-2-methylene-4-methyl-1,3-dioxolane and chlorotrifluoroethylene is 35%.

[0058] The mixture was heated and stirred at 60°C to ensure that the raw materials were fully mixed and dissolved, and then the catalyst perfluoropropionyl peroxide was added, the added mass of which was 0.015% of the mass of perfluoro-2-methylene-4-methyl-1,3-dioxolane. A polymerization reaction was then carried out, and the solvent was removed by evaporation to obtain copolymer A.

[0059] The prepared copolymer A was dissolved in a perfluoro solvent so that the mass concentration of the copolymer A was 0.18%. The perfluoro solvent was able to dissolve the copolymer A well during the dissolution process, ensuring the uniformity and stability of the composite membrane liquid. Subsequently, acetone of 2.5% of the mass of the perfluoro solvent was added to the solution, and the mixture was heated and stirred at 80°C for 20 hours to form a composite membrane liquid.

[0060] The prepared composite layer membrane liquid was coated on the surface of the PTFE base membrane and dried at 80°C for 11 hours to obtain an acid-resistant composite membrane. The PTFE base membrane was prepared by hot pressing polyphenylene sulfide (PPS) non-woven fabric and polytetrafluoroethylene (PTFE), and the pore size of the base membrane was 14 nm.

[0061] (3) 10%wt hydrofluoric acid waste liquid was sent to a distillation tower, and nitrogen was charged into the distillation tower for distillation treatment. The operating absolute pressure of the distillation tower was controlled to be 0.1 MPa, the reflux ratio was 0.1, and the N2 charging rate was 0.1 Nm 3 / h, the top temperature of the distillation tower is 100°C, and the bottom temperature is 110°C; the inner wall of the distillation tower has a polytetrafluoroethylene layer.

[0062] The treated water is produced from the light component production outlet and can be reused as electronic grade ultrapure water; the concentrated hydrofluoric acid is produced from the side line production outlet of the distillation tower.

[0063] (4) The hydrofluoric acid solution after distillation is further sent to the first membrane separation system, and most of the metal ions in the hydrofluoric acid solution are removed by the first membrane separation system equipped with an acid-resistant membrane component.

[0064] (5) The treated hydrofluoric acid solution is further sent to an adsorption tower, where the PHA chelating resin is used as an adsorbent to remove a small amount of metal ions in the solution.

[0065] (6) The treated hydrofluoric acid solution is finally sent to the second membrane separation system. Under the action of the PMMD-CTFE membrane material, the trace metal ions and particulate impurities in the hydrofluoric acid are further removed. The final metal ion removal rate is ≥99.5%. A 37%wt hydrofluoric acid product is collected on the permeate side, achieving the purpose of recycling electronic-grade hydrofluoric acid.

[0066] Example 2

[0067] (1)~(2) are the same as in Example 1.

[0068] (3) 10%wt hydrofluoric acid waste liquid was sent to a distillation tower, and nitrogen was charged into the distillation tower for distillation treatment. The operating absolute pressure of the distillation tower was controlled to be 0.02MPa, the reflux ratio was 0.5, and the N2 charging rate was 0.5 Nm 3 / h, the top temperature of the distillation tower is 60°C, and the bottom temperature is 70°C. The inner wall of the distillation tower has a polytetrafluoroethylene layer. The treated water is produced from the light component production outlet and can be reused as electronic grade ultrapure water; the concentrated hydrofluoric acid is produced from the side line production outlet of the distillation tower.

[0069] (4) The hydrofluoric acid solution after distillation is further sent to the first membrane separation system, and most of the metal ions in the hydrofluoric acid solution are removed by the first membrane separation system equipped with an acid-resistant membrane component.

[0070] (5) The treated hydrofluoric acid solution is further sent to an adsorption tower, where the PHA chelating resin is used as an adsorbent to remove a small amount of metal ions in the solution.

[0071] (6) The treated hydrofluoric acid solution is finally sent to the second membrane separation system. Under the action of the PMMD-CTFE membrane material, the trace metal ions and particulate impurities in the hydrofluoric acid are further removed. The final metal ion removal rate is ≥99.8%. 37.5%wt hydrofluoric acid product is collected on the permeate side, achieving the purpose of recycling electronic grade hydrofluoric acid.

[0072] Example 3

[0073] (1)~(2) are the same as in Example 1.

[0074] (3) 10%wt hydrofluoric acid waste liquid was sent to a distillation tower, and nitrogen was charged into the distillation tower for distillation treatment. The operating pressure of the distillation tower was controlled to be 0.05 MPa, the reflux ratio was 1, and the N2 charging rate was 1 Nm 3 / h, the top temperature of the distillation tower is 90°C, and the bottom temperature is 100°C. The inner wall of the distillation tower has a PFA layer. The treated water is taken out from the light component outlet through the first condenser and can be reused as electronic grade ultrapure water; the concentrated hydrofluoric acid is taken out from the side line outlet of the distillation tower.

[0075] (4) The hydrofluoric acid solution after distillation is further sent to the first membrane separation system, and most of the metal ions in the hydrofluoric acid solution are removed by the first membrane separation system equipped with an acid-resistant membrane component.

[0076] (5) The treated hydrofluoric acid solution is further sent to an adsorption tower, where the PHA chelating resin is used as an adsorbent to remove a small amount of metal ions in the solution.

[0077] (6) The treated hydrofluoric acid solution is finally sent to the second membrane separation system. Under the action of the PMMD-CTFE membrane material, the trace metal ions and particulate impurities in the hydrofluoric acid are further removed. The final metal ion removal rate is ≥99.2%. A 35%wt hydrofluoric acid product is collected on the permeate side, achieving the purpose of recycling electronic-grade hydrofluoric acid.

[0078] Test Case

[0079] The analysis results of the electronic grade hydrofluoric acid products in Examples 1 to 3 are shown in Table 1.

[0080] Table 1 Analysis results of electronic grade hydrofluoric acid products

[0081] index E2 E3 raw material Example 1 Example 2 Example 3 Particles (≥0.5μm) pcs / mL ≤50 ≤25 2286000 20 15 30 Particles (≥1.0μm) pcs / mL ≤25 ≤10 35840000 10 20 15 <![CDATA[Fluorosilicate (SiF4 2- ) mg / kg]]> ≤50 ≤50 10365 20.5 25.0 32.5 <![CDATA[Nitrate (NO3 - ) mg / kg]]> ≤3 ≤3 5.6 1.5 1.0 0.8 <![CDATA[Sulfate (SO4) mg / kg]]> ≤5 ≤0.5 4.3 0.2 0.1 0.05 <![CDATA[Phosphate (PO4 3- ), mg / kg]]> ≤1 ≤0.5 2.6 0.05 0.1 0.08 Aluminum (Al) μg / kg ≤50 ≤10 90.3 3.5 5.5 2.8 Arsenic (As) μg / kg ≤50 ≤10 160.5 2.5 3.2 1.0 Gold (Au) μg / kg ≤20 ≤10 10.8 0.5 0.6 0.5 Silver (Ag) μg / kg ≤20 ≤10 10.3 0.02 0.05 0.1 Boron (B) μg / kg ≤20 ≤10 6200 1.0 0.5 0.2 Barium (Ba) μg / kg ≤50 ≤10 9.6 0.02 0.05 0.05 Beryllium (Be) μg / kg ≤50 ≤10 3.6 0.05 0.06 0.06 Bismuth (Bi) μg / kg ≤50 ≤10 10.2 0.01 0.01 0.05 Calcium (Ca) μg / kg ≤50 ≤10 500 0.5 0.8 0.4 Cadmium (Cd) μg / kg ≤20 ≤10 20 0.8 0.5 0.5 Cobalt (Co) μg / kg ≤50 ≤10 7.6 0.5 0.4 0.2 Chromium (Cr) μg / kg ≤20 ≤10 5.8 0.5 0.8 0.5 Copper (Cu) μg / kg ≤50 ≤10 60 0.4 0.6 0.6 Iron (Fe) μg / kg ≤50 ≤10 89 0.8 0.4 0.4 Gallium (Ga) μg / kg ≤50 ≤10 36 0.4 0.3 0.2 Germanium (Ge) μg / kg ≤50 ≤10 5.6 0.6 0.4 0.8 Indium (In) μg / kg ≤50 ≤10 20.5 0.1 0.1 0.2 Potassium (K) μg / kg ≤50 ≤10 300 0.2 0.2 0.4 Lithium (Li) μg / kg ≤10 ≤5 20 0.2 0.2 0.1 Magnesium (Mg) μg / kg ≤20 ≤10 83 0.4 0.4 0.2 Manganese (Mn) μg / kg ≤20 ≤10 10 0.7 1.2 2.5 Molybdenum (Mo) μg / kg ≤20 ≤10 8.5 1.0 1.5 1.4 Sodium (Na) μg / kg ≤50 ≤10 107700 0.8 1.6 1.8 Nickel (Ni) μg / kg ≤20 ≤10 82 0.8 0.6 0.4 Lead (Pb) μg / kg ≤20 ≤10 897 1.5 1.4 0.8 Platinum (Pt) μg / kg ≤50 ≤10 5.6 0.8 0.8 0.8 Antimony (Sb) μg / kg ≤20 ≤10 8.5 1.0 0.4 0.6 Tin (Sn) μg / kg ≤20 ≤10 9.5 0.4 0.6 0.7 Strontium (Sr) μg / kg ≤50 ≤10 5.8 1.4 1.5 1.2 Titanium (Ti) μg / kg ≤50 ≤10 16 1.8 1.6 2.0 Vanadium (V) μg / kg ≤50 ≤10 5.4 0.4 0.5 0.3 Zinc (Zn) μg / kg ≤50 ≤10 153 1.4 1.8 2.2

[0082] The above table is for illustrating the components contained in hydrofluoric acid, and the content of the components is closely related to the source, but does not limit the applicability of the invention. The hydrofluoric acid product purified and recovered by the method meets the electronic grade reuse standard.

[0083] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A method for purifying and recovering hydrofluoric acid waste liquid in the electronics industry, characterized in that: The steps include: (1) The hydrofluoric acid waste liquid is sent to a distillation tower, and nitrogen is charged into the distillation tower for distillation treatment. The top temperature of the distillation tower is 90°C~100°C, the bottom temperature is 100°C~110°C, the operating pressure is controlled to be 0.1~0.5Mpa, the reflux ratio is 0.1~1, and the nitrogen charging rate is 0.1~1Nm 3 / h; the inner wall of the distillation tower has an anti-corrosion layer; (2) sending the side-line fraction of the distillation tower to a first membrane separation system for membrane separation treatment, wherein the membrane material of the first membrane separation system is an acid-resistant membrane; (3) sending the permeate obtained by the first membrane separation system to an adsorption tower for adsorption treatment to remove some metal ions in the feed liquid; the inner wall of the adsorption tower is provided with an anti-corrosion material layer; the adsorption tower is filled with an acid-resistant chelating resin as an adsorbent; The acid-resistant chelating resin is a PHA chelating resin; the PHA chelating resin is pretreated before use, and the pretreatment includes: Soak the PHA chelating resin in water for 1-1.5 hours, wash it alternately with 4%-6%wt H2SO4, water, and 4%-6%wt NaOH for 3-5 times, and finally wash it with water until it is neutral; (4) The feed liquid treated by the adsorption tower is sent to the second membrane separation system for membrane separation treatment. The membrane material of the second membrane separation system is an acid-resistant metal ion removal membrane, which further removes trace metal ions and particulate impurities in the feed liquid, and electronic grade hydrofluoric acid is recovered on the permeate side of the second membrane separation system. The second membrane separation system includes a plurality of groups of acid-resistant metal ion removal membrane components connected in series or in parallel, and the membrane material of the acid-resistant metal ion removal membrane components is a perfluoro PMMD-CTFE membrane material.

2. The purification and recovery method according to claim 1, characterized in that: The anti-corrosion layer in step (1) is a PTFE layer or a PFA layer.

3. The purification and recovery method according to claim 1, characterized in that: The acid-resistant film described in step (2) is a composite film material of one or more of polyamide, polysulfonamide or polyethyleneimine.

4. The purification and recovery method according to claim 1, characterized in that: The first membrane separation system described in step (2) comprises a plurality of groups of acid-resistant membrane modules connected in series or in parallel, wherein the inner lining of the acid-resistant membrane modules is PFA or PTFE resin.

5. The purification and recovery method according to claim 1, characterized in that: The anti-corrosion material layer described in step (3) is PTFE or PFA.

6. The purification and recovery method according to claim 1, characterized in that: The filling height of the adsorbent accounts for 1 / 3 to 1 / 2 of the height of the adsorption tower.

7. The purification and recovery method according to claim 1, characterized in that: The PHA chelating resin is prepared by the following method: (1-1) sodium persulfate is added as a thermal initiator to a mixed aqueous solution of acrylamide and N,N-methylenebisacrylamide, and the mixture is heated in a water bath at 60°C for 15 to 30 min to initiate a polymerization reaction to obtain a polymer; (1-2) placing the polymer in a hydroxylamine hydrochloride solution for 30 minutes to form hydroxamic acid groups; Then, the pH value was adjusted to 12 with a sodium hydroxide solution, and the mixture was left overnight and neutralized with an acid, and then washed to obtain the PHA chelating resin.

8. The purification and recovery method according to claim 1, characterized in that: The perfluorinated PMMD-CTFE membrane material is prepared by the following steps: (1) Preparation of copolymer A: Perfluoro-2-methylene-4-methyl-1,3-dioxolane and chlorotrifluoroethylene are mixed in a perfluoro solvent and subjected to polymerization reaction under the action of a catalyst to obtain a copolymer A; (2) Preparation of acid-resistant composite film: The copolymer A and acetone are mixed in a perfluorinated solvent at 60-80° C. to obtain a composite layer membrane liquid, and then the composite layer membrane liquid is coated on the surface of a polytetrafluoroethylene-based membrane, and dried to obtain the acid-resistant composite membrane.