A method for removing trace metal ions from hydrogen peroxide

Abstract

A method for removing trace metal ions from hydrogen peroxide is disclosed. This method uses pre-electro-grade hydrogen peroxide as raw material. First, a cation exchange resin is cleaned and pretreated with hydrochloric acid. Then, a cleaned anion exchange resin is mixed with the pretreated cation exchange resin in a specific ratio to form a mixed ion exchange resin, which is then cleaned with ultrapure water. The hydrogen peroxide raw material containing trace metal ion impurities is pre-cooled using a cooling device. The cooled hydrogen peroxide raw material is then passed through one or more mixed ion exchange resin columns using a peristaltic pump. This invention mainly employs resin pretreatment and adjustment of the anion and cation exchange resin ratio to improve the ion exchange rate, thereby enhancing the removal effect of the ion exchange resin on trace metal ions and anions in hydrogen peroxide, ultimately producing ultra-high purity electronic-grade hydrogen peroxide with anion concentrations ≤2 ppb and individual metal ion concentrations ≤10 ppt.

Description

Technical Field

[0001] This invention relates to the purification of hydrogen peroxide and related chemical fields, and particularly to the removal of trace metal ions from hydrogen peroxide using ion exchange. Background Technology

[0002] Electronic-grade hydrogen peroxide, also known as high-purity industrial hydrogen peroxide, is primarily used as a cleaning agent for semiconductor silicon wafers, an etchant, and a photoresist remover. It can also be used in the production of advanced insulating layers, the removal of inorganic impurities from electroplating solutions, the treatment of copper, copper alloys, gallium, and germanium in the electronics industry, and the etching and cleaning of solar silicon wafers. Electronic-grade hydrogen peroxide is mainly derived from purified industrial-grade or food-grade hydrogen peroxide. Currently, the preparation methods for high-quality electronic-grade hydrogen peroxide are controlled by a few companies in the industry, and there is limited relevant literature both domestically and internationally. Currently, commonly used electronic-grade hydrogen peroxide purification technologies include: distillation, adsorption, ion exchange, supercritical extraction, crystallization, and membrane separation, as well as multi-unit integration of the above. Among them, the ion exchange resin method is a solid-liquid heterogeneous diffusion transfer process, which is mostly suitable for removing trace inorganic non-metallic ions, metal ions, and organic impurities from hydrogen peroxide. However, in practical applications, individual anion exchange resin columns and cation exchange resin columns are difficult to reduce trace inorganic ion and metal ion impurities in hydrogen peroxide to a low level. Moreover, due to the influence of the resin structure and manufacturing process, anion exchange resins often experience some metal dissolution during hydrogen peroxide purification, while cation exchange resins will experience sulfate dissolution under the strong oxidizing effect of hydrogen peroxide. Commonly used cation exchange resins are sodium form or hydrogen form. These problems make it difficult for anion and cation exchange resins to meet the requirements for removing trace anions and metal ions from hydrogen peroxide when used alone. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a method for removing trace metal ions from hydrogen peroxide. This invention primarily involves adjusting the mixing ratio of anion and cation exchange resins to promote the removal of H+ ions. + H generated by type cation exchange + and OH - OH- produced by type ion exchange - By generating water with low dissociation, the influence of counterions is eliminated, and ion exchange is carried out thoroughly, thereby improving the removal efficiency of ion exchange resin for trace metal ions in hydrogen peroxide.

[0004] To achieve the above-mentioned objectives, the present invention provides a method for removing trace metal ions from hydrogen peroxide, comprising the following steps:

[0005] (1) Pretreatment of cation exchange resin: Take an appropriate amount of cation exchange resin and put it into a clean container. Use a large amount of ultrapure water to clean it until the conductivity of the washing solution is less than or equal to that of ultrapure water. Drain the ultrapure water from the container, then pour a 1-3% hydrochloric acid solution into the container, and then put the container into an ultrasonic cleaner for a period of time. Finally, filter out the resin and clean the resin with ultrapure water until the cleaning solution is neutral.

[0006] (2) Cleaning of anion exchange resin: Place an appropriate amount of anion exchange resin in a clean container, and then clean the resin with a large amount of ultrapure water until the conductivity of the washing solution is less than or equal to that of ultrapure water.

[0007] (3) The pretreated anion and cation exchange resins from steps (1) and (2) are mixed in a specific ratio to form a mixed ion exchange resin, which is then loaded into the ion exchange resin column.

[0008] (4) Use ultrapure water at a certain temperature to backwash the mixed ion exchange resin column in step (3) until the conductivity of the wash solution is less than or equal to that of the ultrapure water.

[0009] (5) The hydrogen peroxide raw material containing trace impurity ions is cooled down in advance by a cooling device.

[0010] (6) The hydrogen peroxide raw material treated in step (5) is passed through one or more sets of mixed ion exchange resin columns in step (3) at a certain flow rate using a peristaltic pump to obtain electronic grade hydrogen peroxide with a single metal ion ≤10ppt.

[0011] The above technical solution further includes:

[0012] The hydrogen peroxide raw material used in the method has a concentration of 27.5% to 31%, wherein the TOC content is ≤4ppm, the content of a single anionic impurity is ≤10ppb, and the content of a single metal ion impurity is ≤1ppb.

[0013] The cation exchange resin mentioned in step (1) is a styrene and divinylbenzene hydrogen type strong acid cation exchange resin, wherein the divinylbenzene content is 15-18%, preferably 16-18%, and more preferably 16%.

[0014] In step (1), the resin is immersed in a 1-3% hydrochloric acid solution and sonicated for 5-6 hours, and the ultrasonic temperature is controlled at 25-40℃. The amount of 1-3% hydrochloric acid solution added is 3-4 times the volume of the resin to be treated.

[0015] The anion exchange resin mentioned in step (2) is a hydroxide-type strong basic anion exchange resin, which includes any one of UPW550B, IRN78OH, HPR4200OH, HPR4700OH, and ZHPOH-1.

[0016] The height-to-diameter ratio of the ion exchange resin column in step (3) is 2 to 2.5.

[0017] The ratio of anion / cation exchange resins in step (3) is an ion ratio, and the ratio is 0.5-2, more preferably 1:2, 1:1, 3:2 or 2:1.

[0018] The temperature of the ultrapure water in step (4) is 0 to 10°C.

[0019] The hydrogen peroxide raw material containing trace impurity ions described in step (5) is cooled to 0-10°C using a cooling device.

[0020] The flow rate of hydrogen peroxide driven by the peristaltic pump in step (6) is 10-20 BV / h.

[0021] The beneficial effects of this invention include:

[0022] 1. This invention uses hydrochloric acid solution and ultrasound to pretreat cation exchange resin. This mainly utilizes the energy of ultrasound to promote the interaction between the resin and the hydrochloric acid solution, causing the resin to transform into a complete H-type. At the same time, it can wash away organic and inorganic impurities that are often present in new resin to a great extent, ensuring that the resin will not cause new pollution to the purified hydrogen peroxide.

[0023] 2. Based on the strong oxidizing properties of hydrogen peroxide, this invention preferably uses hydrogen peroxide with a divinylbenzene content of 15-18%. + Type II cation exchange resins are used to improve the resin's resistance to strong oxidation and reduce sulfate dissolution. If the divinylbenzene content is below 15%, the resin structure's resistance to strong oxidation decreases, resulting in significant sulfate dissolution during hydrogen peroxide purification. Conversely, if the content is above 18%, the resin structure becomes too compact, increasing ion diffusion resistance and reducing the exchange rate. A cation exchange resin with a divinylbenzene content of 16% is used... + Type cation exchange resin and OH - Type I anion exchange resins are mixed in a specific ratio to promote the H+ purification process of hydrogen peroxide. + H generated by type cation exchange + and OH - OH- produced by type ion exchange -The generation of water with low dissociation eliminates the influence of counterions, ensuring thorough ion exchange and thus improving the removal efficiency of ion exchange resins for trace metal ions in hydrogen peroxide. For example, in some embodiments, when the ratio of anion to cation exchange resin is 3:2, electronic-grade hydrogen peroxide with ≤2ppb for single anions and ≤10ppt for single metal ions can be obtained. Detailed Implementation

[0024] Example 1

[0025] (1) Pretreatment of cation exchange resin: Take an appropriate amount of cation exchange resin (styrene and divinylbenzene sulfonic acid type strong acid cation exchange resin with a divinylbenzene content of 16%) and put it into a clean container. Use a large amount of ultrapure water to clean it until the conductivity of the washing solution is less than or equal to that of ultrapure water. Drain the ultrapure water from the container, then pour a 2% hydrochloric acid solution into the container, and then put the container into an ultrasonic cleaner for a period of time. Finally, filter out the resin and clean the resin with ultrapure water until the cleaning solution is neutral.

[0026] (2) Add an appropriate amount of OH - The type of anion exchange resin (UPW550B) was placed in a clean container, and then the resin was washed with a large amount of ultrapure water until the conductivity of the washing solution was less than or equal to that of the ultrapure water.

[0027] (3) The pretreated anion and cation exchange resins from steps (1) and (2) are mixed at an ion ratio of 1:2 to form a mixed ion exchange resin, which is then loaded into the ion exchange resin column.

[0028] (4) Use ultrapure water at 5°C to backwash the mixed ion exchange resin column in step (3) at a flow rate of 20 BV / h until the conductivity of the wash solution is less than or equal to that of the ultrapure water.

[0029] (5) The hydrogen peroxide raw material containing trace metal ions is cooled to 0°C in advance by a cooling device;

[0030] (6) The hydrogen peroxide raw material after step (5) is passed through a set of mixed ion exchange resin columns in step (3) at a flow rate of 10 BV / h using a peristaltic pump to obtain ultra-high purity electronic grade hydrogen peroxide.

[0031] Example 2

[0032] The method and steps are the same as in Example 1, except that the ion ratio of the pretreated anion and cation exchange resins in step (3) is adjusted to 1:1.

[0033] Example 3

[0034] The method and steps are the same as in Example 1, except that the ion ratio of the pretreated anion and cation exchange resins in step (3) is adjusted to 3:2.

[0035] Example 4

[0036] The method and steps are the same as in Example 1, except that the ion ratio of the pretreated anion and cation exchange resins in step (3) is adjusted to 2:1.

[0037] Example 5

[0038] The method and steps are the same as in Example 3, except that in step (2) OH - The type of anion exchange resin is IRN78OH.

[0039] Example 6

[0040] The method and steps are the same as in Example 3, except that in step (2) OH - The type of anion exchange resin is HPR4200OH.

[0041] Example 7

[0042] The method and steps are the same as in Example 3, except that in step (2) OH - The type of anion exchange resin is HPR4700OH.

[0043] Example 8

[0044] The method and steps are the same as in Example 3, except that in step (2) OH - The type of anion exchange resin is ZHPOH-1.

[0045] Example 9

[0046] The method and steps are the same as in Example 3, except that in step (2) OH - The type of anion exchange resin is UP900OH.

[0047] Example 10

[0048] The method and steps are the same as in Example 3, except that in step (2) OH - The type of anion exchange resin is SA550U.

[0049] Example 11

[0050] The method and steps are the same as in Example 3, except that in step (5), the hydrogen peroxide raw material containing trace impurity ions is cooled to 5°C beforehand using a cooling device.

[0051] Example 12

[0052] The method and steps are the same as in Example 3, except that in step (5), the hydrogen peroxide raw material containing trace impurity ions is cooled to 10°C beforehand using a cooling device.

[0053] Example 13

[0054] The method and steps are the same as in Example 5, except that the peristaltic pump flow rate is adjusted to 15 BV / h in step (6).

[0055] Example 14

[0056] The method and steps are the same as in Example 5, except that the peristaltic pump flow rate is adjusted to 20 BV / h in step (6).

[0057] Example 15

[0058] The method and steps are the same as in Example 7, except that the hydrogen peroxide raw material in step (6) is passed sequentially through two sets of mixed ion exchange resin columns in step (3).

[0059] Comparative Example 1

[0060] (1) Pretreatment of cation exchange resin: Take an appropriate amount of cation exchange resin (styrene and divinylbenzene sulfonic acid type strong acid cation exchange resin with a divinylbenzene content of 16%) and put it into a clean container. Use a large amount of ultrapure water to wash it until the conductivity of the washing solution is less than or equal to that of ultrapure water. Drain the ultrapure water from the container, then pour a 2% hydrochloric acid solution into the container, and then put the container into an ultrasonic cleaner for a period of time. Finally, filter out the resin and wash the resin with ultrapure water until the washing solution is neutral. Put the pretreated resin into a cation exchange resin column, and then wash the resin column with ultrapure water at 5°C until the conductivity of the washing solution is less than or equal to that of ultrapure water.

[0061] (2) Add an appropriate amount of OH - The type of anion exchange resin (UPW550B) was packed into the anion exchange resin column, and then the resin was washed with a large amount of ultrapure water until the conductivity of the wash solution was less than or equal to that of the ultrapure water.

[0062] (3) The hydrogen peroxide raw material containing trace impurity ions is cooled to 5°C in advance using a cooling device;

[0063] (4) The hydrogen peroxide raw material treated in step (3) is passed through the cation exchange resin column and the anion exchange resin column in steps (1) and (2) in sequence using a peristaltic pump at a flow rate of 15 BV / h to obtain a hydrogen peroxide sample with a low metal ion content.

[0064] Comparative Example 2

[0065] (1) Pretreatment of cation exchange resin: Take an appropriate amount of cation exchange resin (styrene and divinylbenzene sulfonic acid type strong acid cation exchange resin with a divinylbenzene content of 16%) and put it into a clean container. Use a large amount of ultrapure water to wash it until the conductivity of the washing solution is less than or equal to that of ultrapure water. Drain the ultrapure water from the container, then pour a 2% hydrochloric acid solution into the container, and then put the container into an ultrasonic cleaner for a period of time. Finally, filter out the resin and wash the resin with ultrapure water until the washing solution is neutral. Put the pretreated resin into a cation exchange resin column, and then wash the resin column with ultrapure water at 5°C until the conductivity of the washing solution is less than or equal to that of ultrapure water.

[0066] (2) Add an appropriate amount of OH - The type of anion exchange resin (UPW550B) was packed into the anion exchange resin column, and then the resin was washed with a large amount of ultrapure water until the conductivity of the wash solution was less than or equal to that of the ultrapure water.

[0067] (3) The hydrogen peroxide raw material containing trace impurity ions is cooled to 5°C in advance using a cooling device;

[0068] (4) The hydrogen peroxide raw material treated in step (3) was passed sequentially through the anion exchange resin column and the cation exchange resin column in steps (1) and (2) at a flow rate of 15 BV / h using a peristaltic pump to obtain a hydrogen peroxide sample with a low metal ion content. In this embodiment, the order of the anion and cation exchange resin columns was adjusted. It has been proven that simply passing through the resin columns and adjusting the order of the resin columns cannot achieve a good removal effect.

[0069] Comparative Example 3

[0070] (1) Pretreatment of cation exchange resin: Take an appropriate amount of cation exchange resin (styrene and divinylbenzene sulfonic acid type strong acid cation exchange resin with a divinylbenzene content of 16%) and put it into a clean container. Use a large amount of ultrapure water to clean it until the conductivity of the washing solution is less than or equal to that of ultrapure water. Drain the ultrapure water from the container, then pour a 2% hydrochloric acid solution into the container, and then put the container into an ultrasonic cleaner for a period of time. Finally, filter out the resin and clean the resin with ultrapure water until the cleaning solution is neutral.

[0071] (2) Add an appropriate amount of OH - The type of anion exchange resin (UPW550B) was placed in a clean container, and then the resin was washed with a large amount of ultrapure water until the conductivity of the washing solution was less than or equal to that of the ultrapure water.

[0072] (3) The pretreated anion and cation exchange resins from steps (1) and (2) are mixed at an ion ratio of 3:2 to form a mixed ion exchange resin, which is then loaded into the ion exchange resin column.

[0073] (4) Use ultrapure water at 25°C to backwash the mixed ion exchange resin column in step (3) at a flow rate of 20 BV / h until the conductivity of the wash solution is less than or equal to that of the ultrapure water.

[0074] (5) Pass the room temperature hydrogen peroxide raw material through a set of mixed ion exchange resin columns in step (3) at a flow rate of 15 BV / h using a peristaltic pump to obtain a hydrogen peroxide sample with low metal ion content.

[0075] Comparative Example 4

[0076] (1) Add an appropriate amount of H + A type of cation exchange resin (a styrene and divinylbenzene sulfonic acid-based strong acid cation exchange resin with a divinylbenzene content of 16%) is packed into an anion exchange resin column, and then the resin is washed with a large amount of ultrapure water until the conductivity of the wash solution is less than or equal to that of the ultrapure water.

[0077] (2) Add an appropriate amount of OH - The type of anion exchange resin (UPW550B) was placed in a clean container, and then the resin was washed with a large amount of ultrapure water until the conductivity of the washing solution was less than or equal to that of the ultrapure water.

[0078] (3) The pretreated anion and cation exchange resins from steps (1) and (2) are mixed at an ion ratio of 3:2 to form a mixed ion exchange resin, which is then loaded into the ion exchange resin column.

[0079] (4) Use ultrapure water at 5°C to backwash the mixed ion exchange resin column in step (3) at a flow rate of 20 BV / h until the conductivity of the wash solution is less than or equal to that of the ultrapure water.

[0080] (5) The hydrogen peroxide raw material is passed through a set of mixed ion exchange resin columns in step (3) at a flow rate of 15 BV / h using a peristaltic pump to obtain a hydrogen peroxide sample with a low metal ion content.

[0081] Table 1. Metal ion content in hydrogen peroxide after purification in Examples 1-6

[0082]

[0083] Table 1-1 (Continued) shows the metal ion content in the purified hydrogen peroxide from Examples 7-12.

[0084]

[0085]

[0086] Tables 1-2 (continued) show the metal ion content in hydrogen peroxide after purification in Examples 13-15 and Comparative Examples 1-4.

[0087]

[0088] Table 3. Anion content in the purified hydrogen peroxide of Examples 1-15 and Comparative Examples 1-4

[0089]

[0090]

[0091] Analysis of Tables 1, 2, and 3 shows that the mixed ion exchange resin prepared by using anion exchange resin and cation exchange resin can make ion exchange more thorough, thereby improving the removal effect of anion / cation exchange resin on trace impurity ions in hydrogen peroxide. When the ion ratio of anion / cation exchange resin is 3:2, it has the best removal effect on metal ion impurities and anion impurities in hydrogen peroxide. After purification by this mixed ion exchange resin column, ultra-high purity electronic grade hydrogen peroxide can be obtained.

[0092] In Comparative Examples 1 and 2, when pre-cooled hydrogen peroxide was passed sequentially through a cation exchange resin column followed by an anion exchange resin column, or vice versa, the removal efficiency of the resin for trace metal ion impurities and anion impurities in the hydrogen peroxide was significantly reduced. In Comparative Example 3, the hydrogen peroxide was not cooled; during the purification process, the temperature rose, causing partial damage to the resin structure and thus reducing the purification efficiency. In Comparative Example 4, the cation exchange resin was not pretreated; the removal efficiency of trace metal ions such as Na, Fe, and Ca, and SO42- in the subsequently purified hydrogen peroxide was significantly reduced. 2- The ion concentration is too high.

[0093] The above embodiments are merely preferred technical solutions of the present invention and not intended to limit the invention. The embodiments and features described herein can be arbitrarily combined without conflict. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for removing trace metal ions from hydrogen peroxide, characterized in that: Includes the following steps: (1) Pretreatment of cation exchange resin: The cation exchange resin is washed with ultrapure water until the conductivity of the washing solution is less than or equal to that of ultrapure water. Then hydrochloric acid solution is added, and the resin is ultrasonically washed with ultrapure water until the washing solution is neutral. The cation exchange resin is a styrene and divinylbenzene sulfonic acid type strong acid cation exchange resin, and the divinylbenzene content in the cation exchange resin is 15-18%. (2) Cleaning of anion exchange resin: Use ultrapure water to clean the anion exchange resin until the conductivity of the washing solution is less than or equal to that of ultrapure water. The anion exchange resin is a hydroxide-type strong basic anion exchange resin, which includes any one of IRN78OH, HPR4200OH, HPR4700OH, and ZHPOH-1. (3) Mix the pretreated anion / cation exchange resins from steps (1) and (2) to form a mixed ion exchange resin, and then pack it into an ion exchange resin column. The ratio of the anion / cation exchange resins is the ion ratio, and the ratio is 3:

2. (4) Use ultrapure water to backwash the mixed ion exchange resin column in step (3) until the conductivity of the wash solution is less than or equal to that of ultrapure water. (5) Cool the hydrogen peroxide raw material containing trace metal ions to 0°C beforehand; (6) Pass the hydrogen peroxide raw material treated in step (5) through a mixed ion exchange resin column to obtain electronic grade hydrogen peroxide with a single metal ion concentration of ≤10 ppt.

2. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: The cation exchange resin in step (1) contains 16-18% divinylbenzene.

3. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: The ultrasound time in step (1) is 5-6 hours and the ultrasound temperature is 25-40℃.

4. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: In step (1), the mass concentration of hydrochloric acid solution is 1-3%, and the amount of hydrochloric acid solution added is 3-4 times the volume of the resin to be treated.

5. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: The height-to-diameter ratio of the ion exchange resin column in step (3) is 2 to 2.

5.

6. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: The temperature of the ultrapure water in step (4) is 0-10℃.

7. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: The hydrogen peroxide raw material containing trace impurity metal ions mentioned in step (5) has a concentration of 27.5~31%, wherein the TOC content is ≤4 ppm, the content of a single anionic impurity is ≤10 ppb, and the content of a single metal ion impurity is ≤1 ppb.

8. The method for removing trace metal ions from hydrogen peroxide as described in claim 1, characterized in that: In step (6), the flow rate of the hydrogen peroxide raw material through the mixed ion exchange resin column is 10~20 BV / h.

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