Preparation method of electronic-grade sodium hydroxide

Abstract

The invention relates to the technical field of chemical reagents, and particularly discloses a preparation method of electronic-grade sodium hydroxide. According to the method, recycling of the waste is achieved, the cheap arsenic-containing sodium hydroxide waste is converted into the electronic-grade sodium hydroxide with the high additional value, the production cost of the electronic-grade sodium hydroxide is effectively reduced, an important industrial raw material-chlorine can be generated in the anode region at the same time, and the production cost is reduced. The carbon-supported manganese-silver gas diffusion electrode can reduce the electrolysis voltage on the premise of keeping the current density unchanged, energy conservation and consumption reduction are achieved, and the requirement of the electronic industry for electronic-grade sodium hydroxide can be fully met.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of chemical reagents, in particular to a preparation method of electronic-grade sodium hydroxide. BACKGROUND

[0002] Integrated circuits refer to products obtained by adopting a certain process to connect nearly one hundred million semiconductor devices such as transistors and basic electronic elements such as resistors, capacitors and inductors on a small substrate, and then packaging the integrated circuits into a tube shell to obtain a micro electronic component. The development of the electronic industry including the tip chip is a national basic policy and a strong support and foundation for the country, and the electronic-grade chemicals are indispensable basic materials for producing the tip chip.

[0003] Electronic-grade sodium hydroxide is a high-purity chemical product widely used in the electronic industry. The optimization and development of the preparation process of electronic-grade sodium hydroxide are crucial to improve the quality of electronic products and meet market demand. At present, most of the electronic-grade sodium hydroxide on the market is prepared by using industrial-grade sodium hydroxide as raw material, removing metal ions through multi-stage filtration, distillation and purification, and improving the purity to meet the requirements of electronic-grade chemicals.

[0004] According to the related technology, the inventors believe that the process flow of the electronic-grade sodium hydroxide in the related technology is long, the operation is complex, and the equipment requirement is high, which leads to high energy consumption and production cost of the production process, and it is difficult to fully meet the demand of the electronic industry for electronic-grade sodium hydroxide. SUMMARY

[0005] In the related technology, the production process of electronic-grade sodium hydroxide has high energy consumption and high production cost, and it is difficult to fully meet the demand of the electronic industry for electronic-grade sodium hydroxide. In order to improve this defect, the application provides a preparation method of electronic-grade sodium hydroxide.

[0006] The application provides a preparation method of electronic-grade sodium hydroxide, which adopts the following technical scheme: A preparation method of electronic-grade sodium hydroxide, comprising the following steps: (1) adding arsenic-containing sodium hydroxide into ultrapure water to obtain a sodium hydroxide crude solution for standby use; the arsenic-containing sodium hydroxide is a waste produced by antimony refining arsenic removal process; the sodium hydroxide crude solution contains trivalent arsenic, trivalent antimony, tetravalent selenium, sodium sulfate and sodium carbonate; (2) adding an oxidizing agent, a saturated calcium hydroxide solution, barium hydroxide and iron sulfate into the sodium hydroxide crude solution in sequence, carrying out filtration after standing and precipitating, recrystallizing the filtrate, obtaining high-purity sodium hydroxide, and dissolving the high-purity sodium hydroxide in water to obtain a high-purity sodium hydroxide solution; (3) taking the gas diffusion electrode as the cathode, the platinum electrode as the anode, the sodium ion exchange membrane as the diaphragm, the sodium chloride solution as the anode liquid, the high-purity sodium hydroxide solution as the cathode liquid, introducing oxygen into the cathode liquid, and performing water bath heating on the cathode liquid and the anode liquid, to obtain the electronic-grade sodium hydroxide after electrolysis.

[0007] By adopting the technical scheme, the waste, i.e. the sodium hydroxide containing arsenic, generated in the antimony refining arsenic removal process is purified, the trivalent arsenic, the trivalent antimony and the tetravalent selenium in the sodium hydroxide containing arsenic are converted into sodium arsenate, sodium antimonate and sodium selenate respectively by an oxidizing agent, and the sodium antimonate is separated from the solution in the form of a precipitate. After the saturated calcium hydroxide solution is added, the calcium hydroxide fully reacts with sodium carbonate, sodium sulfate and sodium selenate in the solution to form a precipitate, the sodium arsenate is preliminarily removed, and a new sodium hydroxide is formed in the double decomposition reaction; after the barium hydroxide is added, the sodium arsenate can be further removed in the form of barium arsenate precipitate; after the iron sulfate is added, the remaining sodium arsenate can be further removed in the form of iron arsenate precipitate, and the sodium hydroxide solution with extremely low arsenic content can be obtained after standing and filtering. At this time, since the sodium arsenate which greatly interferes with the recrystallization method has been mostly removed, the high-purity sodium hydroxide can be directly obtained by the recrystallization method. Thereafter, the high-purity sodium hydroxide solution is used as the cathode liquid, and the sodium chloride solution is used as the anode liquid to perform electrolysis. In the cathode region, the oxygen is reduced by the carbon-loaded manganese-silver gas diffusion electrode, and the hydroxyl ions are generated in the cathode liquid, and the sodium ions in the anode region migrate to the cathode region through the sodium ion exchange membrane, further improving the purity of the sodium hydroxide in the cathode liquid, and obtaining the electronic-grade sodium hydroxide. The application realizes the recycling of waste, converts the inexpensive sodium hydroxide containing arsenic waste into the high-value-added electronic-grade sodium hydroxide, effectively reduces the production cost of the electronic-grade sodium hydroxide, and the anode region can also simultaneously produce the important industrial raw material, i.e. chlorine, and the carbon-loaded manganese-silver gas diffusion electrode can reduce the electrolysis voltage under the premise of maintaining the current density, achieving energy saving and consumption reduction. The preparation method can reduce the production energy consumption and production cost of the electronic-grade sodium hydroxide, overcome the defects in the related art, and fully meet the demand of the electronic industry for the electronic-grade sodium hydroxide.

[0008] Preferably, in step (3) of the method, the rate of introducing oxygen into the cathode liquid is 1.5-2.5 mL / min.

[0009] By adopting the technical scheme, the rate of introducing oxygen into the cathode liquid is preferred, and maintaining sufficient oxygen supply rate can fully promote the electrode reaction in the cathode region, which is helpful to reduce the electrolysis voltage, thereby achieving the effect of energy saving and consumption reduction.

[0010] Preferably, in step (3) of the method, the current density is 300-350 mA / cm 2The electrolysis is carried out under the condition of 88-92℃.

[0011] By adopting the technical scheme, the current density range is preferred, and the electrolysis voltage can be maintained at a lower level in the range, so that the energy saving and consumption reduction effect is realized.

[0012] As preferred, the electrolysis is carried out under the condition of 88-92℃ in step (3) of the method.

[0013] By adopting the technical scheme, the temperature range of the electrolysis reaction is preferred, and when the electrolysis reaction occurs at a lower temperature, the electron transfer efficiency in the solution is lower, and when the temperature is higher, the evaporation rate of the solution is accelerated, which also affects the transfer of electrons. When the temperature is in the above range, the transfer rate of electrons is ideal, which helps to reduce the electrolysis voltage, so that the energy saving and consumption reduction effect is realized.

[0014] As preferred, the sodium chloride in step (2) is industrial-grade sodium chloride.

[0015] By adopting the technical scheme, since the sodium ion exchange membrane is used in the electrolysis process, and the cathode and the anode are isolated, even the industrial-grade sodium chloride containing impurities can meet the demand for providing sodium ions, and additional purification treatment of sodium chloride is not required, which effectively reduces the production cost compared with the traditional technology.

[0016] As preferred, in step (2) of the method, hydrogen peroxide is selected as the oxidizing agent, and the weight ratio between the hydrogen peroxide contained in the hydrogen peroxide and the arsenic element contained in the crude sodium hydroxide solution is (10-12):1.

[0017] By adopting the technical scheme, hydrogen peroxide can convert trivalent arsenic, trivalent antimony and tetravalent selenium in arsenic-containing sodium hydroxide into sodium arsenate, sodium antimonate and sodium selenate. The application preferably selects the ratio of hydrogen peroxide content in hydrogen peroxide to arsenic, which can fully realize the oxidation of arsenic, so as to facilitate the removal of these impurity elements in the form of precipitate in the subsequent step.

[0018] As preferred, in step (2) of the method, the ratio of the volume of saturated calcium hydroxide solution to the total weight of sodium carbonate and sodium sulfate is 4.3-4.5 mL:1 g.

[0019] By adopting the technical scheme, the application preferably selects the dosage range of the saturated calcium hydroxide solution, which helps to fully precipitate the arsenic element.

[0020] As preferred, in step (2) of the method, the weight of the added barium hydroxide is 40-45 times the total weight of the arsenic element contained in the crude sodium hydroxide solution.

[0021] By adopting the technical scheme, the application preferably uses the amount range of the barium hydroxide, which helps to fully realize the precipitation of arsenic elements.

[0022] As a preference, in step (2) of the method, the added iron sulfate has a weight of 200-205 times of the total weight of arsenic elements contained in the crude sodium hydroxide solution.

[0023] By adopting the technical scheme, the application preferably uses the amount range of the iron sulfate, which helps to fully realize the precipitation of arsenic elements.

[0024] As a preference, the gas diffusion electrode is a carbon-supported manganese-silver gas diffusion electrode, which is prepared according to the following method: (1) After mixing an acidic potassium permanganate solution and carbon black, oil bath heating is performed, and then the solution is cooled to room temperature, the solution is filtered, the filter residue is washed and dried, and then the filter residue is calcined to obtain a manganese-carbon composite; (2) The manganese-carbon composite is added to water for emulsification, the obtained emulsion is mixed with a PTFE solution, and then sprayed on the surface of carbon cloth, followed by drying and calcination to obtain a manganese-carbon electrode; (3) Silver plating is performed on the surface of the manganese-carbon electrode, and after washing and drying, a carbon-supported manganese-silver gas diffusion electrode is obtained.

[0025] By adopting the technical scheme, the application uses potassium permanganate and carbon black as precursors, and a manganese-carbon electrode with catalytic effect is prepared by an impregnation method. Silver is further loaded on the manganese-carbon electrode by silver plating to obtain a carbon-supported manganese-silver gas diffusion electrode. The carbon-supported manganese-silver gas diffusion electrode can make oxygen fully participate in the reaction in the cathode region, and can also maintain a low electrolysis voltage, which helps to reduce the energy consumption of producing electronic-grade sodium hydroxide.

[0026] In summary, the application has the following beneficial effects: 1. The application converts low-cost arsenic-containing sodium hydroxide waste into high-purity sodium hydroxide, and prepares a catholyte using the high-purity sodium hydroxide. High-value-added electronic-grade sodium hydroxide is produced by electrolysis process, which overcomes the defects in the related art, effectively reduces the production cost of electronic-grade sodium hydroxide, and can fully meet the demand of electronic industry for electronic-grade sodium hydroxide.

[0027] 2. The application uses a sodium ion exchange membrane in the electrolysis process, and isolates the cathode and anode, so that even industrial-grade sodium chloride containing impurities can meet the demand for providing sodium ions, without the need for additional purification treatment of sodium chloride. Compared with the traditional technology, the production cost is effectively reduced.

[0028] 3、The application uses potassium permanganate and carbon black as precursors to prepare a manganese-carbon electrode with catalytic effect by an impregnation method, and further loads silver on the manganese-carbon electrode by silver plating to obtain a carbon-supported manganese-silver gas diffusion electrode. The carbon-supported manganese-silver gas diffusion electrode can make oxygen fully participate in the reaction in the cathode region and maintain a low electrolysis voltage, which helps to reduce the energy consumption of producing electronic-grade sodium hydroxide. DETAILED DESCRIPTION

[0029] The application will be further described in detail below in combination with examples, preparation examples and comparative examples. The raw materials involved in the application can be obtained by market purchase.

[0030] Preparation example of carbon-supported manganese-silver gas diffusion electrode The following takes preparation example 1 as an example for illustration.

[0031] Preparation example 1 In this preparation example, the carbon cloth is prepared according to the following steps: (1) Take 60 mL of water, add 1.5 g of carbon black, and emulsify for 30 min to obtain a diffusion layer slurry. Add 0.6 g of PTFE to the diffusion layer slurry, divide the mixture into four parts, and spray it on the substrate material. After each spraying, perform a hot pressing, and after the last hot pressing, calcine at 325℃ for 5 h to obtain a diffusion layer; (2) Take 50 mL of water, add 1.5 g of carbon black, and emulsify for 30 min to obtain a microporous layer slurry. Add 0.05 g of PTFE solution with a concentration of 60 wt% to the microporous layer slurry, mix uniformly, and spray it on one side of the diffusion layer. After calcining at 325℃ for 3 h, a microporous layer is formed, and a carbon cloth is obtained.

[0032] This preparation example provides a carbon-supported manganese-silver gas diffusion electrode, which is prepared according to the following method: (1) Mix an acidic potassium permanganate solution with a potassium permanganate concentration of 1 mol / L and a pH of 5.5 with VXC72R carbon black at a carbon-manganese weight ratio of 3:1, heat in an 85℃ oil bath for 1 h, then cool the solution to 25℃, filter the solution, wash and dry the filter residue, then heat at a rate of 5℃ / min to 350℃, and calcine the filter residue at 350℃ for 5 h to obtain a manganese-carbon composite, which is ready for use; (2) Add the manganese-carbon composite to water, emulsify at a speed of 1500 rpm for 30 min, mix the obtained emulsion with a 60 wt% PTFE solution, and spray it on the surface of the carbon cloth prepared above, then dry and calcine to obtain a manganese-carbon electrode. In this step, the manganese-carbon composite loading on the surface of the carbon cloth is 5.25 mg / cm 2 , and the amount of PTFE is 0.08 g; (3) Perform silver plating on the surface of the manganese-carbon electrode to make the silver loading reach 2 mg / cm2 After washing and drying, a carbon-supported manganese-silver gas diffusion electrode is obtained. Examples

[0033] Examples 1-5 The following is described by taking Example 1 as an example.

[0034] Example 1 In this example, industrial-grade sodium chloride is selected as the sodium chloride, arsenic-containing sodium hydroxide is a waste produced by antimony refining arsenic removal process, and 30wt% hydrogen peroxide is selected as the oxidizing agent. The weight ratio between the hydrogen peroxide contained in the hydrogen peroxide and the arsenic element contained in the crude sodium hydroxide solution is 10:1; the ratio of the volume of the saturated calcium hydroxide solution to the total weight of sodium carbonate and sodium sulfate contained in the crude sodium hydroxide solution is 4.3mL:1g; the weight of barium hydroxide is 40 times the total weight of arsenic element contained in the crude sodium hydroxide solution; and the amount of iron sulfate is 200 times the total weight of arsenic element contained in the crude sodium hydroxide solution.

[0035] The present example provides a preparation method of electronic-grade sodium hydroxide, comprising the following steps: (1) adding arsenic-containing sodium hydroxide into ultrapure water to obtain a crude sodium hydroxide solution for standby use; in this step, the composition of the crude sodium hydroxide solution is as follows: arsenic(III) 4.8g / L, sodium hydroxide 170g / L, sodium carbonate 63.6g / L, sodium sulfate 25.6g / L, antimony(III) 0.39g / L, and selenium(IV) 0.23g / L; (2) adding an oxidizing agent, a saturated calcium hydroxide solution, barium hydroxide and iron sulfate into the crude sodium hydroxide solution in sequence, performing filtration after standing and precipitating, recrystallizing the filtrate to obtain high-purity sodium hydroxide, and dissolving with water to obtain a high-purity sodium hydroxide solution; (3) taking the gas diffusion electrode prepared in Preparation Example 1 as a cathode, taking a platinum electrode as an anode, taking a sodium ion exchange membrane as a diaphragm, taking a saturated sodium chloride solution as an anode liquid, taking a 30wt% high-purity sodium hydroxide solution as a cathode liquid, passing oxygen into the cathode liquid at a rate of 1mL / min, and performing water bath heating on the cathode liquid and the anode liquid at 85°C, to obtain electronic-grade sodium hydroxide under the condition of 400mA / cm 2

[0036] The main difference between Examples 1-5 is the amount of reagent used in step (2) as shown in Table 1.

[0037] Table 1 Amount of reagent used in step (2) Examples 5-9 ​The difference between Examples 5-9 is that the rate of oxygen flow into the cathode solution in step (3) is different, as shown in Table 2.

[0038] Table 2 Rate of oxygen flow Sample Rate of oxygen passage / (mL / min) Example 5 1 Example 6 1.5 Example 7 2 Example 8 2.5 Example 9 3 Examples 10-13 The difference between Examples 10-13 and Example 7 is that the electrolysis is carried out at different current densities in step (3), as shown in Table 3.

[0039] Table 3 Current density Sample Current density / (mA / cm 2 ) Example 7 400 Example 10 370 Example 11 350 Example 12 320 Example 13 300 Examples 14-17 The difference between Examples 14-17 and Example 13 is that the electrolysis is carried out at different temperatures, as shown in Table 4.

[0040] Table 4 Electrolysis temperature Comparative Examples Comparative Example 1 This comparative example provides a method for preparing electronic-grade sodium hydroxide, comprising the following steps: (1) Industrial sodium chloride is prepared into a sodium chloride aqueous solution with ultrapure water, and large-particle impurities are removed by filtration, for standby use; (2) The filtrate in step (1) is collected, and an excess of barium chloride solution is added for reaction. After the reaction is completed, sulfate ions are removed by filtration; (3) The filtrate in step (2) is collected, and sodium carbonate solution is added for reaction. After the reaction is completed, calcium and magnesium ions and excess barium ions are removed by filtration; (4) The filtrate in step (3) is collected, and the pH value is adjusted to 12 with NaOH solution. The remaining magnesium ions are removed by filtration, and the obtained filtrate is recrystallized to remove iron ions, to obtain high-purity sodium chloride solid. The high-purity sodium chloride solid is prepared into a saturated sodium chloride solution with water; (5) The hydrogen evolution electrode is used as the cathode, the platinum electrode is used as the anode, and the saturated sodium chloride solution is used as the electrolyte. The electrolysis is carried out at a temperature of 85°C and a current density of 400 mA / cm 2 to obtain electronic-grade sodium hydroxide.

[0041] Comparative Example 2 The difference between this comparative example and Example 1 is that step (2) is operated according to the following method: To the crude sodium hydroxide solution, an oxidizing agent, a saturated calcium hydroxide solution, and barium hydroxide were sequentially added, and after standing and precipitation, filtration was performed. The filtrate was recrystallized in the same manner as in Example 1 to obtain solid sodium hydroxide, which was dissolved in water to obtain a sodium hydroxide solution. This sodium hydroxide solution was used as the cathode solution.

[0042] Comparative Example 3 This comparative example differs from Example 1 in that step (2) was performed as follows: To the crude sodium hydroxide solution, an oxidizing agent and a saturated calcium hydroxide solution were sequentially added, and after standing and precipitation, filtration was performed. The filtrate was recrystallized in the same manner as in Example 1 to obtain solid sodium hydroxide, which was dissolved in water to obtain a sodium hydroxide solution. This sodium hydroxide solution was used as the cathode solution.

[0043] Comparative Example 4 This comparative example differs from Example 1 in that step (2) was performed as follows: To the crude sodium hydroxide solution, an oxidizing agent and a saturated calcium hydroxide solution were sequentially added, and after standing and precipitation, filtration was performed. The filtrate was recrystallized in the same manner as in Example 1 to obtain solid sodium hydroxide, which was dissolved in water to obtain a sodium hydroxide solution. This sodium hydroxide solution was used as the cathode solution.

[0044] Performance test method I. Arsenic removal efficiency Examples 1-5 and Comparative Examples 2-4 were used as test objects, and the arsenic content in the crude sodium hydroxide solution and the filtrate obtained after standing and precipitation in step (2) was measured, respectively. The difference between the arsenic contents was calculated, and then the ratio between this difference and the initial arsenic content was calculated. This ratio was taken as the arsenic removal rate, and the results are shown in Table 5.

[0045] II. Electrolysis voltage Examples 1-17 and Comparative Example 1 were used as test objects, and the electrolysis voltage in step (3) was measured under a given current density, and the results are shown in Table 6.

[0046] III. Product testing The electronic-grade sodium hydroxide of Examples 1-17 was subjected to component testing according to the provisions of Q / ME015-2019 "Sodium Hydroxide (Electronic Grade)", and the results are shown in Table 7.

[0047] Table 5 Arsenic removal rate Sample Arsenic removal / % Example 1 99.97 Example 2 99.98 Example 3 99.97 Example 4 99.98 Example 5 99.99 Comparative Example 2 99.82 Comparative Example 3 80.35 Comparative Example 4 0.01 Table 6 Electrolysis voltage Table 7 Product testing As can be seen from Examples 1-5 and Comparative Examples 2-4 in combination with Table 5, the arsenic removal rates measured in Comparative Examples 2-4 are all lower than those in Examples 1-5, and the arsenic removal rates in Examples 1-5 can reach as high as 99.99%. After the three-stage precipitation of calcium hydroxide, barium hydroxide and iron sulfate in Examples 1-5, the arsenate has been removed thoroughly, and the inexpensive sodium hydroxide waste containing arsenic has been converted into high-purity sodium hydroxide. Thereafter, the catholyte is prepared by using the high-purity sodium hydroxide, and the electronic-grade sodium hydroxide with high added value is produced by electrolysis process. As can be seen from Table 7, the electronic-grade sodium hydroxide produced in the application meets the requirements in all indexes, overcomes the defects in the related art, effectively reduces the production cost of electronic-grade sodium hydroxide, and can fully meet the demand of electronic industry for electronic-grade sodium hydroxide.

[0048] As can be seen from Examples 1-5 and Comparative Example 1 in combination with Table 6, the electrolysis voltages measured in Examples 1-5 are significantly lower than that in Comparative Example 1, because the carbon-supported manganese-silver gas diffusion electrode in the application can not only make oxygen in the cathode region fully participate in the reaction, but also maintain a relatively low electrolysis voltage, which is helpful to reduce the energy consumption for producing electronic-grade sodium hydroxide.

[0049] As can be seen from Example 5 and Examples 6-9 in combination with Table 6, in step (3), when the rate of oxygen flow into the catholyte is 1.5-2.5 mL / min, the electrolysis voltage is relatively low, indicating that the energy consumption for producing electronic-grade sodium hydroxide can be reduced in this range.

[0050] As can be seen from Example 7, Examples 10-13 in combination with Table 6, in step (3), when the electrolysis is carried out at 300-350 mA / cm 2 , the electrolysis voltage is relatively low, indicating that the energy consumption for producing electronic-grade sodium hydroxide can be reduced in this range.

[0051] As can be seen from Example 13, Examples 14-17 in combination with Table 6, in step (3), when the electrolysis is carried out at 88-92℃, the electrolysis voltage is relatively low, indicating that the energy consumption for producing electronic-grade sodium hydroxide can be reduced in this range.

[0052] The above examples are merely an explanation of the application, but not a limitation of the application, and those skilled in the art can make modifications to the examples of the application without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the application, they are protected by the patent law.

Claims

1. A method for preparing electronic-grade sodium hydroxide, characterized in that, Includes the following steps: (1) Add arsenic-containing sodium hydroxide to ultrapure water to obtain a crude sodium hydroxide solution for later use; the arsenic-containing sodium hydroxide is a waste product generated from the antimony refining arsenic removal process; the crude sodium hydroxide solution contains trivalent arsenic, trivalent antimony, tetravalent selenium, sodium sulfate and sodium carbonate; (2) Add oxidant, saturated calcium hydroxide solution, barium hydroxide and ferric sulfate to the crude sodium hydroxide solution in sequence. After standing and precipitation, filter the solution and recrystallize the filtrate to obtain high-purity sodium hydroxide. Dissolve the filtrate in water to obtain a high-purity sodium hydroxide solution. (3) Using a gas diffusion electrode as the cathode, a platinum electrode as the anode, a sodium ion exchange membrane as the diaphragm, a sodium chloride solution as the anolyte, and a high-purity sodium hydroxide solution as the catholyte, oxygen is introduced into the catholyte, and the catholyte and anolyte are heated in a water bath. After electrolysis, electronic-grade sodium hydroxide is obtained.

2. The method for preparing electronic-grade sodium hydroxide according to claim 1, characterized in that, In step (3) of the method, the rate at which oxygen is introduced into the catholyte is 1.5-2.5 mL / min.

3. The method for preparing electronic-grade sodium hydroxide according to claim 2, characterized in that, In step (3) of the method, at 300-350 mA / cm 2 Electrolysis is carried out under the following conditions.

4. The method for preparing electronic-grade sodium hydroxide according to claim 3, characterized in that, In step (3) of the method, electrolysis is carried out at 88-92℃.

5. The method for preparing electronic-grade sodium hydroxide according to claim 1, characterized in that, The sodium chloride in step (2) is industrial grade sodium chloride.

6. The method for preparing electronic-grade sodium hydroxide according to claim 1, characterized in that, In step (2) of the method, hydrogen peroxide is selected as the oxidant, and the weight ratio between the hydrogen peroxide contained in the hydrogen peroxide and the arsenic element contained in the crude sodium hydroxide solution is (10-12):

1.

7. The method for preparing electronic-grade sodium hydroxide according to claim 5, characterized in that, In step (2) of the method, the ratio of the volume of saturated calcium hydroxide solution to the total weight of sodium carbonate and sodium sulfate is 4.3-4.5 mL: 1 g.

8. The method for preparing electronic-grade sodium hydroxide according to claim 1, characterized in that, In step (2) of the method, the weight of added barium hydroxide is 40-45 times the total weight of arsenic in the crude sodium hydroxide solution.

9. The method for preparing electronic-grade sodium hydroxide according to claim 8, characterized in that, In step (2) of the method, the weight of added ferric sulfate is 200-205 times the total weight of arsenic in the crude sodium hydroxide solution.

10. The method for preparing electronic-grade sodium hydroxide according to claim 1, characterized in that, The gas diffusion electrode is a carbon-supported manganese-silver gas diffusion electrode, which is prepared according to the following method: (1) After mixing acidic potassium permanganate solution and carbon black, the mixture is heated in an oil bath. The solution is then cooled to room temperature, filtered, and the filter residue is washed and dried. The filter residue is then calcined to obtain a manganese-carbon composite. (2) The manganese-carbon composite was added to water for emulsification. The resulting emulsion was mixed with PTFE solution and sprayed onto the surface of carbon cloth. Then it was dried and calcined to obtain a manganese-carbon electrode. (3) Silver plating is performed on the surface of the manganese carbon electrode, and after washing and drying, a carbon-supported manganese silver gas diffusion electrode is obtained.

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