JP2013010988A - Method for regenerating waste liquor containing tetraalkylammonium hydroxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for regenerating a waste liquor containing TAAH (Tetraalkylammonium Hydroxide), by which a high purity TAAH aqueous solution is efficiently recovered as a product by industrially advantageously regenerating the waste liquor containing TAAH by a relatively simple operation.SOLUTION: The method for regenerating a TAAH-containing waste liquor includes: a neutralization step 1 of neutralizing the TAAH-containing waste liquor; and an electrolysis step of electrolyzing the neutralized waste liquor obtained in the neutralization step 1, in an electrolytic cell 2 partitioned into an anode chamber 5 and a cathode chamber 6 with a cationic ion exchange membrane 4, and in the method, a high purity TAAH aqueous solution being a product is recovered from the cathode chamber side of the electrolytic cell. Further, in the method, the turbidity (JIS K0101 measurement method) of the neutralized waste liquor is controlled to be 5,000 ppm or less, the flow velocity (linear velocity) of an anode circulation solution circulating in the anode chamber is maintained within the range of 1.5×10to 25×10m/s, and the product of the TAAH aqueous solution having a TAAH concentration of 15 to 30 mass% is recovered from the cathode chamber side.

Description

  This invention occurs in the manufacturing process of electronic components such as semiconductor devices, liquid crystal display devices, printed circuit boards, etc. using a tetraalkylammonium hydroxide aqueous solution as a photoresist developer or an alkaline cleaning solution. The present invention relates to a method for recycling a tetraalkylammonium hydroxide-containing waste liquid containing organic impurities such as an activator.

  In the manufacturing process of electronic parts such as semiconductor devices, liquid crystal display devices, printed circuit boards, etc., with the development of electronic technology in recent years, photoresist developers used in the development process after photoetching, silicon wafers and liquid crystal glass substrates The amount of alkaline cleaning liquid used in this cleaning process has increased, and along with this, the discharge amount of alkaline waste liquid such as photoresist developing waste liquid and alkaline cleaning waste liquid discharged from these manufacturing processes has also increased rapidly. In addition, the photoresist developer and alkali cleaning solution used in the manufacturing process of such electronic components are extremely high in purity due to ultra-high integration in semiconductor devices and pattern miniaturization in printed circuit boards and liquid crystal display devices. In particular, in order to meet this requirement, water such as tetramethylammonium hydroxide (TMAH) or β-hydroxyethyltrimethylammonium hydroxide (choline) is required. An aqueous solution of tetraalkylammonium oxide (TAAH) is mainly used.

  And about the alkaline waste liquid discharged | emitted from the manufacturing process of these electronic components, besides containing TAAH derived from a photoresist developing solution or an alkaline cleaning liquid, for example, a photoresist, a surfactant, etc. Various organic impurities from the development process and the washing process are included, such as organic impurities derived from the above, and cannot be disposed of as they are.

Therefore, conventionally, activated sludge treatment with a large-scale facility after neutralization treatment and release, or disposal such as concentration and incineration by means of evaporation method, reverse osmosis membrane method, etc. In addition, a method for removing tetraalkylammonium ions (TAA ⁺ ; TAA ions) by adsorbing them on a cation exchange resin has been proposed.

In addition, TAAH contained in an alkaline waste solution containing TAA ions (TAA ⁺ ) such as a photoresist development waste solution and an alkaline cleaning waste solution (that is, a TAAH-containing waste solution) itself is an extremely useful substance as an organic alkali. For this reason, many attempts have been made to collect and reuse it. For example, as a method of recovering and reusing high-purity TAAH from a photoresist developing waste solution, Patent Document 1 (Japanese Patent Laid-Open No. 07-328,642) discloses a method by electrodialysis, and Patent Document 2 (Japanese Patent Laid-Open No. 11-116). 142,380) is a method using chromatographic separation, and Patent Document 3 (Japanese Patent Laid-Open No. 2002-361,249) is a method using a nanofiltration membrane (NF film). JP 2003-190,949 A) discloses a method using a cation exchange resin.

  Further, separately from the above method, the TAAH-containing waste liquid containing organic impurities after being used as a photoresist developer or the like is brought into contact with hydrochloric acid or carbon dioxide gas to neutralize TAAH in the TAAH-containing waste liquid. The neutralized solution containing TAAH hydrochloride and carbonate is introduced into the anode chamber side of the electrolytic cell having an anode chamber and a cathode chamber partitioned by a cation exchange membrane, and the salt of TAAH is electrolyzed. Several proposals have also been made on the so-called “electrolysis method” in which TAAH is concentrated and purified, recovered as a high-purity tetraalkylammonium hydroxide aqueous solution (TAAH aqueous solution), and reused.

  For example, in Patent Document 5 (Japanese Patent Laid-Open No. 04-228,587), a developing waste liquid (TAAH-containing waste liquid containing organic impurities) is concentrated, and then the resulting concentrated developing waste liquid is de-COD treated to remove COD components. It is possible to remove the developed COD-treated developer waste solution into the anode chamber of the electrolytic cell partitioned with a cation exchange membrane and perform electrolytic treatment, and recover a high-purity TAAH aqueous solution from the cathode chamber of this electrolytic cell. In addition, Patent Document 6 (Patent No. 3,110,513) proposes performing electrolytic treatment in multiple stages.

  In Patent Document 7 (Patent No. 3,216,998), TAAH-containing waste liquid containing organic impurities is concentrated, then neutralized to remove insolubilized impurities, and then treated with activated carbon to adsorb and remove organic impurities. Furthermore, it is disclosed that electrodialysis is performed using an electrolytic cell having an anode chamber and a cathode chamber partitioned by a cation exchange membrane, and a high-purity TAAH aqueous solution is recovered. Patent Document 8 (WO 2006) / 059760 A1) includes a developer waste solution (TAAH-containing waste solution containing organic impurities) that exceeds the specified amount of metal impurities, diluted with an unused developer solution, etc. It is disclosed that the photoresist is separated and removed by separation treatment, and then electrolytic treatment is performed using an electrolytic cell having an anode chamber and a cathode chamber partitioned by a cation exchange membrane to regenerate the TAAH aqueous solution. Patent Document 9 (Patent No. 3,543,915) Publication No. 4) and Patent Document 10 (Patent No. 4,085,987) are combined with electrodialysis and / or electrolysis and adsorption / removal of impurities using a cation exchange resin or anion exchange resin to produce a photoresist developing waste solution (containing organic impurities). (TAAH-containing waste liquid) is reclaimed.

  The method of recovering high-purity TAAH aqueous solution from TAAH-containing waste liquid containing organic impurities by these electrolysis methods is to recover TAA ions concentrated on the cathode chamber side through the cation exchange membrane of the electrolytic cell as TAAH aqueous solution. It is possible to efficiently separate and remove organic impurities and heavy metal ions derived from photoresists and surfactants contained in TAAH-containing waste liquid, and continuous operation is also possible. Compared with electrodialysis, it can be handled with a single electrolytic membrane, has a simple structure, and can be easily handled with the same technology and equipment as the conventional TAAH electrolytic manufacturing process. This method is more effective than the method.

  However, in this electrolytic method, tar-like substances derived from organic impurities in the TAAH-containing waste liquid adhere to the positive electrode in the anode chamber and the cation exchange membrane that partitions the anode chamber and the cathode chamber during the electrolytic treatment. In addition to gradually depositing and covering the surface of the positive electrode or cation exchange membrane in the anode chamber, the electrolytic efficiency during the electrolytic treatment is remarkably impaired, and the expensive positive electrode or cation exchange membrane is damaged.

  Therefore, conventionally, the TAAH-containing waste liquid is neutralized with hydrochloric acid, carbon dioxide gas, etc., and the insolubilized impurities generated in the neutralized liquid are added prior to the electrolytic treatment of the obtained neutralized liquid. Separation and removal are performed.

  However, even when the electrolytic treatment of the neutralization treatment liquid is performed after separating and removing the insolubilized impurities in this way, the above-described problem of tar-like substance adhesion does not become a serious problem in laboratory-scale treatment operations. In industrial scale processing operations, this problem of tar-like substance adhesion still occurs, resulting in problems such as a reduction in electrolytic efficiency and damage of the positive electrode and cation exchange membrane. Therefore, in the electrolytic treatment of TAAH-containing waste liquid on an industrial scale, even if the insolubilized impurities in the neutralization treatment liquid are separated and removed in advance, the TAAH-containing waste liquid as the electrolysis proceeds in the anode chamber In order to prevent the occurrence of organic impurity leakage and leakage of organic impurities into the TAAH aqueous solution in the cathode chamber, it is inevitable that the organic impurities in the inside are concentrated and the tar-like substance adheres to the positive electrode or the electrolytic membrane. In addition, it is inevitable to maintain and manage the electrolytic cell in a costly manner, such as the total exchange of the anode chamber liquid and the exchange of the positive electrode and the cation exchange membrane.

  In addition, the separation and removal of insolubilized impurities from the neutralized solution of TAAH-containing waste liquid before electrolytic treatment is usually performed by microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis method. (RO) and other membrane filtration methods are used. In these filtration operations, insolubilized impurities in the neutralized liquid derived from organic impurities (photoresist, surfactant, etc.) in the TAAH-containing waste liquid As a result, the filter membrane is easily contaminated and clogged, and it is necessary to frequently replace the filter membrane in order to carry out smooth electrolytic treatment in the electrolytic cell, and these filter membranes are generally expensive. Therefore, there is a problem that the replacement of the filter membrane is too costly.For this reason, although the electrolysis method is an effective method for regenerating the TAAH-containing waste liquid, it has not necessarily spread to a satisfactory level. Not Is information. Moreover, the problem of such tar-like substance adhesion in the electrolytic bath and the problem of separating and removing insolubilized impurities from the neutralizing solution before the electrolytic treatment are the photoresists in which the TAAH-containing waste liquid contains organic impurities derived from the photoresist. It appears more remarkably in the developing waste liquid.

  Furthermore, according to various studies by the present inventors, the neutralization treatment liquid obtained by performing the neutralization treatment of the TAAH-containing waste liquid, when the insoluble impurities are separated and removed by performing the filtration operation by the membrane filtration method described above. However, it has been found that the recovery rate of TAAH recovered as a high-purity TAAH aqueous solution is not necessarily improved by performing electrolysis of TAAC in the subsequent electrolysis step.

JP 07-328,642 A Japanese Patent Laid-Open No. 11-142,380 JP 2002-361,249 A Japanese Patent Laid-Open No. 2003-190,949 Japanese Patent Laid-Open No. 04-228,587 Japanese Patent No. 3,110,513 Japanese Patent No. 3,216,998 WO 2006/059760 A1 Japanese Patent No. 3,543,915 Japanese Patent No. 4,085,987

  Therefore, the present inventors have made an unexpected investigation as a result of earnestly examining a method for recycling a tetraalkylammonium hydroxide-containing waste liquid that can solve the problems of the electrolytic method while taking advantage of the electrolytic method described above. The turbidity (JIS K0101 measurement method) of the neutralized solution obtained by neutralizing the TAAH-containing waste solution with carbon dioxide gas is controlled to a predetermined value or less, and the inside of the anode chamber of the electrolytic cell is then maintained. By maintaining the flow rate (linear velocity) of the circulating anodic circulating fluid at a specified value, adhesion of tar-like substances derived from organic impurities in the TAAH-containing waste liquid to the positive electrode and cation exchange membrane of the electrolytic cell is greatly reduced. Not only to prevent contamination of the electrolytic cell, but also to greatly reduce the load on the filtration operation of the neutralization liquid introduced to the anode chamber side of the electrolytic cell (reduction of the filtration load), From the cathode chamber side of the electrolytic cell It is possible to recover TAAH aqueous solution with a constant TAAH concentration and high purity as a product (improvement of TAAH recovery rate). The present invention was completed by finding that it can be recovered.

  Further, the present inventors prepared an anode circulation liquid by adding a neutralization treatment liquid to the residual anolyte without discarding the residual anolyte remaining in the anode chamber of the electrolytic cell after the electrolysis step. In this circulating anode fluid, the tetraalkylammonium carbonate (TAAC) concentration is controlled to a predetermined value and the turbidity (JIS K0101 measurement method) is controlled to a predetermined value or less, and is circulated in the anode chamber of the electrolytic cell. By maintaining the flow rate (linear velocity) of the anodic circulating fluid at a predetermined value, it is possible to further improve the above-described electrolytic cell contamination prevention, reduction of filtration load, and improvement of TAAH recovery rate. As a result, it is industrially advantageous. The present inventors completed the present invention by regenerating the waste liquid containing TAAH and recovering a high-purity TAAH aqueous solution as a product.

  Accordingly, an object of the present invention is to regenerate a TAAH-containing waste liquid with a relatively simple operation and industrially advantageously, and to recover a TAAH-containing waste liquid that can efficiently recover a high-purity TAAH aqueous solution as a product. Is to provide.

That is, the first invention of the present application is a neutralization that neutralizes tetraalkylammonium hydroxide in the TAAH-containing waste liquid by blowing carbon dioxide into the TAAH-containing waste liquid containing tetraalkylammonium hydroxide (TAAH) and organic impurities. And a neutralization treatment solution containing tetraalkylammonium carbonate (TAAC) produced in this neutralization step is introduced into the anode chamber side of the electrolytic cell partitioned into an anode chamber and a cathode chamber by a cation exchange membrane. An electrolysis step of recovering a TAAH aqueous solution purified from the cathode chamber side by performing electrolysis of the TAAC,
In the electrolysis step, the neutralization treatment liquid introduced into the anode chamber is circulated as an anode circulation liquid on the anode chamber side, and a TAAH aqueous solution having a lower concentration than the TAAH aqueous solution collected from the cathode chamber is circulated on the cathode chamber side. Circulating as a cathode circulation liquid, removing organic impurities from the TAAH-containing waste liquid to recover a high-purity product TAAH aqueous solution, a method for treating a tetraalkylammonium hydroxide-containing waste liquid,
While controlling the turbidity (JIS K0101 measurement method) of the neutralization treatment liquid obtained in the neutralization step and introduced into the anode chamber side of the electrolytic cell in the electrolysis step to 5000 ppm or less,
In the electrolysis step, the flow rate (linear velocity) of the anode circulating liquid circulating in the anode chamber is maintained within a range of 1.5 × 10 ^{−3 to} 25 × 10 ⁻³ m / sec,
From the cathode chamber side of the electrolytic cell, a tetraalkylammonium hydroxide-containing waste liquid regeneration treatment method is characterized in that a cathode circulating liquid having a TAAH concentration of 15 to 30% by mass is recovered as a product TAAH aqueous solution.

In addition, the second invention of the present application is a neutralization in which carbon dioxide gas is blown into a TAAH-containing waste liquid containing tetraalkylammonium hydroxide (TAAH) and organic impurities, and the tetraalkylammonium hydroxide in the TAAH-containing waste liquid is neutralized. And a neutralization treatment solution containing tetraalkylammonium carbonate (TAAC) produced in this neutralization step is introduced into the anode chamber side of the electrolytic cell partitioned into an anode chamber and a cathode chamber by a cation exchange membrane. An electrolysis step of recovering a TAAH aqueous solution purified from the cathode chamber side by performing electrolysis of the TAAC,
In the electrolysis step, the neutralization treatment liquid introduced into the anode chamber is circulated as an anode circulation liquid on the anode chamber side, and a TAAH aqueous solution having a lower concentration than the TAAH aqueous solution collected from the cathode chamber is circulated on the cathode chamber side. Circulating as a cathode circulation liquid, removing organic impurities from the TAAH-containing waste liquid to recover a high-purity product TAAH aqueous solution, a method for treating a tetraalkylammonium hydroxide-containing waste liquid,
In the electrolysis step, after the electrolysis in the electrolysis step is completed and the product TAAH aqueous solution is recovered from the cathode chamber of the electrolytic cell, the neutralization solution is added to the residual anolyte remaining in the anode chamber of the electrolytic cell. An anodic circulating fluid is prepared, electrolysis of the obtained anodic circulating fluid is performed, and the electrolytic treatment for recovering the purified TAAH aqueous solution from the cathode chamber side is repeated a plurality of times,
The turbidity (JIS K0101 measurement method) of the neutralization treatment solution obtained in the neutralization step and introduced into the anode chamber side of the electrolytic cell in the electrolysis step is controlled to 5000 ppm or less, and the electrolytic cell anode in the electrolysis step The turbidity (JIS K0101 measurement method) of the anode circulating liquid before electrolytic treatment prepared indoors is controlled to 5000 ppm or less,
In the electrolysis step, the TAAC concentration of the anode circulating liquid circulating in the anode chamber is maintained within a range of 18 to 30% by mass, and the flow rate (linear velocity) of the anode circulating liquid is 1.5 × 10 ^{−3 to} 25 ×. The tetraalkyl hydroxide is maintained within a range of 10 ⁻³ m / sec, and the cathode circulating solution having a TAAH concentration of 15 to 30% by mass is recovered as a product TAAH aqueous solution from the cathode chamber side of the electrolytic cell. This is a method for recycling an ammonium-containing waste liquid.

  In the present invention, the TAAH-containing waste liquid to be subjected to regeneration treatment is not particularly limited as long as it is a waste liquid that can be made into a neutralization treatment liquid containing TAAC by blowing carbon dioxide into the TAAH-containing waste liquid. TAAH aqueous solution containing impurities or TAAC aqueous solution in which part or most of TAAH is contained as TAAC may be used. Generally, a photoresist developer or an alkaline cleaning solution used in the manufacturing process of electronic components Examples thereof include photoresist developing waste liquids and alkali cleaning waste liquids, and mixed waste liquids obtained by mixing these waste liquids.

  And about the neutralization process which neutralizes TAAH in waste liquid by blowing carbon dioxide into such TAAH-containing waste liquid, TAAH in TAAH-containing waste liquid should just become TAAC, the processing conditions of the neutralization process, etc. There is no particular limitation on the conditions, and the conditions for neutralizing the TAAH-containing waste liquid with carbon dioxide gas that have been conventionally used can be employed as they are. As the neutralization treatment of the TAAH-containing waste liquid, carbon dioxide gas based on the electrolysis of TAAC is generated from the anode chamber side of the electrolytic cell in the next electrolysis step. Therefore, the generated carbon dioxide gas is preferably used. By introducing it into the neutralization process with an air pump through a pipe, it is better to use it for neutralization of TAAH-containing waste liquid, so that the carbon dioxide generated in the electrolysis process of the electrolysis process is released into the atmosphere, It can be recycled for neutralization treatment in the sum process.

  In addition, as the carbon dioxide gas used for neutralizing the TAAH-containing waste liquid in this way, the amount of carbon dioxide required for neutralizing the TAAH-containing waste liquid when the carbon dioxide generated by the TAAC electrolytic treatment is circulated. However, in such a case, fresh carbon dioxide gas may be introduced, and if there is a TAAC electrolysis facility as a TAAH manufacturing facility, Carbon dioxide generated in this TAAC electrolysis facility may be recovered and used. By recovering the carbon dioxide gas generated in the TAAC electrolysis step and using it for the neutralization treatment of the TAAH-containing waste liquid, the release of carbon dioxide gas to the atmosphere can be reduced as much as possible.

  In the first and second inventions of the present application, the neutralization treatment liquid obtained in this neutralization step is then introduced into the electrolysis step, and in this electrolysis step, a cation exchange membrane is used to separate the anode chamber and the cathode chamber. It is introduced into the anode chamber side of the partitioned electrolytic cell and electrolyzed, and this electrolytic treatment regenerates a high-purity TAAH aqueous solution from which organic impurities are removed as much as possible. The product is recovered as a product from the cathode chamber side. At this time, the neutralization treatment liquid introduced into the anode chamber is circulated as an anode circulation solution on the anode chamber side, and is recovered from the cathode chamber on the cathode chamber side. A TAAH aqueous solution having a concentration lower than that of the TAAH aqueous solution is circulated as a cathode circulation solution, whereby the TAAH concentration of the cathode circulation solution (TAAH aqueous solution) on the cathode chamber side of the electrolytic cell is usually 15% by mass to 30% by mass, preferably 20% to 26% by mass The following decomposition is continued until a TAAH concentration of 15 to 30% by mass is recovered as a product. If the TAAH concentration of the recovered product TAAH aqueous solution is lower than 15% by mass, the electrical conductivity is lowered and the voltage is increased to lower the electrolysis efficiency. Conversely, if the TAAH concentration is higher than 30% by mass, the electrical conductivity is lowered due to an increase in viscosity. However, the voltage increases, the electrolytic efficiency decreases, and as a result, there arises a problem of crystallization.

Here, it is necessary to manage the neutralization solution introduced into the anode chamber side of the electrolytic cell in the electrolysis step so that the turbidity measured by the JIS K0101 measurement method is maintained at 5000 ppm or less, preferably 3000 ppm or less. When the turbidity (JIS K0101) of this neutralization treatment liquid exceeds 5000 ppm, the flow rate (linear velocity) of the anode circulating liquid circulating in the anode chamber of the electrolytic cell in the electrolysis process is 1.5 × 10 ^−3. Even if maintained within a range of ˜25 × 10 ⁻³ m / sec, it is possible to prevent tar-like substances derived from organic impurities in the TAAH-containing waste liquid from adhering to the positive electrode or cation exchange membrane of the electrolytic cell. It becomes difficult. The turbidity (JIS K0101) of the neutralization solution can be controlled by any method as long as it can be controlled to 5000 ppm or less as a result. In the process, tar-like substances adhere to the filter, the filter is likely to be clogged, maintenance becomes difficult, and filtration after concentration is preferably a neutralizing solution because of high viscosity and poor filtration efficiency. It is better to carry out the filtration process.

In the first and second inventions of the present application, in the electrolysis process, the flow rate (linear velocity) of the anode circulating liquid circulating in the anode chamber of the electrolytic cell is set to 1.5 × 10 ⁻³ m / sec or more and 25 × 10. ^-3 m / sec or less, preferably 2 x 10 ^-3 m / sec or more and 20 x 10 ^-3 m / sec or less. When the flow rate (linear velocity) of this anodic circulating fluid is slower than 1.5 × 10 ⁻³ m / sec, carbon dioxide gas generated by the electrolysis of TAAC in the anode chamber stays near the surface of the positive electrode or cation exchange membrane. As a result, the flow of the neutralization solution near the surface of the positive electrode or the cation exchange membrane becomes irregular and the flow rate is further slowed down. The insolubilized impurities generated during the treatment become tar-like and adhere to the surface of the positive electrode or cation exchange membrane over time. On the contrary, the flow rate (linear velocity) of the anodic circulating liquid is 25 × 10 ⁻³ m / sec. If it is faster, other problems such as damage to the electrode / electrolytic plate of the electrolytic cell and liquid leakage from the seal will occur.

  In the second invention of the present application, in this electrolysis process, after the electrolysis in the previous electrolysis process is completed and the product TAAH aqueous solution is recovered from the cathode chamber of the electrolytic cell, it remains in the anode chamber of the electrolytic cell. The neutralization treatment liquid is added to the residual anolyte to prepare an anode circulation liquid, and the resulting anode circulation liquid is electrolyzed to recover the purified TAAH aqueous solution from the cathode chamber side a plurality of times. At this time, the turbidity (JIS K0101 measurement method) of the anode circulating liquid prepared in the anode chamber of the electrolytic cell before electrolytic treatment is controlled to 5000 ppm or less, and the anode circulating liquid circulating in the anode chamber is controlled. The TAAC concentration is maintained within the range of 18% by mass to 30% by mass, preferably 20% by mass to 28% by mass in terms of TAAH. When the TAAC concentration of the anodic circulating liquid is lower than 18% by mass, the electric conductivity is lowered, the voltage is increased and the electrolysis efficiency is lowered, and the addition of the concentrated neutralizing liquid causes the same volume to be within the above concentration range. On the other hand, when it exceeds 30% by mass, the viscosity increases, the flow rate decreases, the electrical conductivity decreases, the voltage increases, and the electrolytic efficiency decreases. Arise.

  In the second invention of the present application, the neutralization treatment liquid added to the residual anolyte when preparing the anodic circulating liquid is added to the residual anolyte, resulting in a TAAC concentration of 18 to Although it is not particularly limited as long as it can be maintained within the range of 30% by mass, it is preferably obtained by concentrating the neutralization solution in advance in order to continuously maintain the TAAC concentration within the above range. A concentrated neutralization treatment liquid having a TAAC concentration of 40% by mass to 50% by mass, more preferably 42% by mass to 48% by mass, is preferably used.

  Furthermore, in the first and second inventions of the present application, the electrolytic cell used in the electrolysis step is preferably circulated in the anode chamber in order to smoothly circulate the anode circulation solution and the cathode circulation solution in the electrolysis step. It is preferable that an anode circulating liquid tank for temporarily storing the anode circulating liquid and a cathode circulating liquid tank for temporarily storing the cathode circulating liquid circulating in the cathode chamber be provided side by side, whereby the anode in the anode chamber of the electrolytic cell is provided. The flow of the circulating liquid and the flow of the cathode circulating liquid in the cathode chamber can be stabilized.

  According to the first and second inventions of the present application, the product TAAH aqueous solution recovered from the electrolysis step has a TAAH concentration of 15 to 30% by mass and an organic impurity concentration of usually 5 mg / mol or less, preferably 4 mg. The concentration of iron (Fe), which is a problem as a metal impurity because it causes defects in electronic components, etc. (iron concentration) is usually 5 mg / L or less, preferably 4 mg / L. Even if it is as it is, it is highly purified to the level which can be used as a photoresist developing solution or an alkali washing liquid in the manufacturing process of electronic parts, such as a semiconductor device, a liquid crystal display device, and a printed board.

  However, if necessary, the product TAAH aqueous solution recovered from the electrolysis process is brought into contact with a cation exchange resin and introduced into a demetalization impurity process that further removes metal impurities remaining in the product TAAH aqueous solution as much as possible. Of course, an ultra-high purity TAAH aqueous solution from which metal impurities are removed as much as possible from this demetalization impurity step may be recovered.

  According to the method for regenerating a tetraalkylammonium hydroxide-containing waste liquid of the present invention, a tetraalkylammonium hydroxide-containing waste liquid is industrially advantageously regenerated by a relatively simple operation to obtain a high-purity tetraalkylammonium hydroxide aqueous solution. Can be recovered.

FIG. 1 is an explanatory view showing an example of a regeneration treatment apparatus for carrying out the regeneration treatment method for a tetraalkylammonium hydroxide-containing waste liquid of the present invention.

  Hereinafter, the embodiment of the method for reclaiming a tetraalkylammonium hydroxide-containing waste liquid according to the present invention will be described in detail based on an example of using a regeneration treatment apparatus shown in the accompanying drawings.

  FIG. 1 shows an example of a regeneration processing apparatus for carrying out the TAAH-containing waste liquid regeneration processing method of the present invention. This regeneration treatment apparatus is for performing a neutralization treatment for neutralizing a TAAH-containing waste liquid, and an electrolytic treatment for a neutralization treatment liquid obtained by neutralizing the TAAH-containing waste liquid in the neutralization tank 1. And an evaporation concentrator 3 for concentrating and supplying the neutralization solution obtained in the neutralization tank 1 to the electrolytic tank 2. It consists of and.

  The electrolytic cell 2 includes an anode chamber 5 and a cathode chamber 6 that are partitioned by a cation exchange membrane 4, and between the anode 5 a in the anode chamber 5 and the cathode 6 a in the cathode chamber 6. A DC power source 7 for supplying a current having a predetermined current density is provided, and the anode chamber 5 side is provided with an anode after electrolyzing a neutralization treatment liquid (anode circulation liquid) introduced into the anode chamber 5. An anodic circulating liquid tank 8 for temporarily storing the anodic circulating liquid after the electrolytic treatment discharged from the chamber 5 and introducing it again into the anodic chamber 5 to perform the circulating liquid is provided. Is temporarily stored until the TAAH aqueous solution (cathode circulatory solution) containing TAA ions generated by electrolytic treatment of the neutralization treatment solution and passing through the cation exchange membrane 4 reaches a predetermined TAAH concentration. A cathode circulation liquid tank 9 is provided for circulation to the cathode chamber 6 again.

  In this regeneration treatment apparatus, a waste liquid introduction line 10 for introducing a TAAH-containing waste liquid into the neutralization tank 1 is connected to the neutralization tank 1 and carbon dioxide for introducing carbon dioxide gas into the neutralization tank 1. A gas introduction line 11 is connected, and a transfer for transferring the neutralized liquid produced in the neutralization tank 1 into the evaporation concentrator 3 between the neutralization tank 1 and the evaporation concentrator 3. A line 12 is provided, and further, a concentration obtained by concentrating the neutralization treatment liquid in the evaporation concentrator 3 as necessary between the evaporation concentrator 3 and the anode circulating liquid tank 8 of the electrolytic cell 2. A transfer line 13 is provided for transferring the neutralization treatment liquid to the anode circulation liquid tank 8.

  Further, the electrolytic cell 2 includes an anode-side circulation line 14 extending from the outlet side of the anode chamber 5 to the inlet side of the anode chamber 5 through the anode circulation solution tank 8 and a cathode circulation solution tank from the outlet side of the cathode chamber 6. 9 is provided with a cathode-side circulation line 15 that leads to the inlet side of the cathode chamber 6 through 9, and the anode-side circulation line 14 extends from the anode circulation liquid tank 8 to the inlet side of the anode chamber 5. Further, a liquid feed pump 16 is provided, and the anode circulating liquid tank 8 is a drain for extracting the anode circulating liquid in the anode chamber 5, the anode circulating liquid tank 8 and the anode side circulation line 14 after the completion of the electrolytic treatment. An outlet line 17 is provided, and the cathode side circulation line 15 is provided with a liquid feed pump 16 from the cathode circulation liquid tank 9 to the inlet side of the cathode chamber 6, and further, cathode circulation. In the liquid tank 9, the cathode circulation liquid (TAAH aqueous solution) regenerated to a high concentration by electrolytic treatment is extracted. A collection line 18 for collecting the carbon dioxide gas is provided at the outlet side of the anode chamber 5 to collect carbon dioxide gas generated in the anode chamber 5 during the electrolytic treatment and introduce it into the neutralization tank 1. A gas recovery line 19 is provided.

  The cathode circulation liquid tank 9 is composed of a TAAH aqueous solution having a lower concentration than the product TAAH aqueous solution recovered from the cathode chamber 6 before electrolytic treatment of the anode circulation liquid (neutralization treatment liquid) in the anode chamber 5. A cathode circulation liquid preparation line 20 for supplying water necessary for preparing the cathode circulation liquid and a TAAH aqueous solution is provided, and the evaporation concentrator 3 includes a neutralization liquid in the neutralization treatment liquid. There is provided an exhaust line 21 for steam that is discharged when the water is evaporated and the neutralized liquid is concentrated.

  When performing the regeneration treatment of the TAAH-containing waste liquid using this regeneration treatment apparatus, first, the TAAH-containing waste liquid is introduced into the neutralization tank 1 from the waste liquid introduction line 10 and then the neutralization tank 1 from the carbon dioxide introduction line 11. The neutralized solution of TAAH containing waste liquid is brought into contact with the carbon dioxide gas introduced into the inside (neutralization step), and the neutralized solution obtained in this neutralization step is electrolyzed via transfer lines 12 and 13. An anode circulating liquid is introduced into an anode circulating liquid tank 8 provided on the anode chamber 4 side of the tank 2, and a cathode circulating liquid tank 9 provided on the cathode chamber 6 side of the electrolytic tank 2 is provided in the cathode circulating liquid tank 9. A high-purity, low-concentration TAAH aqueous solution (cathode circulating solution) is filled in advance through the preparation line 20.

  Here, the turbidity of the anodic circulating liquid (neutralized liquid) introduced into the anodic circulating liquid tank 8 is measured by JIS K0101 measurement method. A simple filtration treatment is performed on the part or the whole, and the turbidity is adjusted to 5000 ppm or less, preferably 3000 ppm.

For example, when carrying out electrolytic treatment at a high TAAC concentration, such as when carrying out the second invention, the neutralization solution obtained in the neutralization step is introduced into the evaporation concentrator 3 from the transfer line 12. In the evaporative concentrator 3, it is concentrated to a predetermined TAAC concentration, and the resulting concentrated neutralization treatment liquid is introduced into the anode circulation liquid tank 8 from the transfer line 13, and this concentration neutralization treatment liquid is supplied to the anode circulation liquid. Used as Of course, in this case, the concentration of the TAAC concentration may be adjusted by adding water into the anode circulating liquid tank 8.
If necessary, a transfer line that bypasses the evaporation concentrator 3 is provided between the neutralization tank 1 and the anode circulation liquid tank 8 of the electrolytic tank 2, or the TAAC concentration of the anode circulation liquid is set in the anode circulation liquid tank 8. You may provide the introduction line of the water for adjusting.

After introducing the anode circulation liquid (neutralization liquid) into the anode circulation liquid tank 8 and introducing the cathode circulation liquid (high purity and low concentration TAAH aqueous solution) into the cathode circulation liquid tank 9, The liquid feed pumps 16 provided on the anode side circulation line 14 on the anode chamber 5 side and the cathode side circulation line 15 on the cathode chamber 6 side are driven, respectively, and the anode circulation liquid is supplied to the anode chamber 5 side and the cathode chamber 6 side. Are circulated in the cathode circulation liquid, and the flow rate of the anode circulation liquid is 1.5 × 10 ⁻³ m / sec. 25 × 10 ⁻³ m / sec. While maintaining the following range, the DC power supply 7 applies a DC voltage between the anode 5a in the anode chamber 5 and the cathode 6a in the cathode chamber 6 to cause a current having a predetermined current density to flow, and the anode circulating liquid ( The electrolytic treatment of the neutralization treatment liquid) is started (electrolysis step).

  Here, in the first invention of the present application, during the electrolytic treatment of the anode circulation liquid (neutralization treatment liquid) in this electrolysis step, the TAAC of the anode circulation liquid flowing through the anode-side circulation line 14 on the anode chamber 5 side. The concentration is measured, and the electrolytic treatment is stopped before the anodic circulating liquid reaches a predetermined TAAC concentration or less, and the residual anolyte remaining in the anode chamber 5 is extracted from the anodic circulating liquid tank 8 through the extraction line 17. At the same time, the cathode circulation liquid (TAAH aqueous solution) regenerated to a desired TAAH concentration is extracted from the cathode circulation liquid tank 9 as a product TAAH aqueous solution from the collection line 18 and collected.

  In the electrolysis process according to the first aspect of the invention, the anode circulation is performed by the operation of extracting the residual anolyte having a reduced TAAC concentration and the operation of introducing the neutralization treatment liquid (or concentrated neutralization treatment liquid) from the neutralization tank 1. Replacement of the liquid (neutralization liquid) is repeated several times as necessary, and when the TAAH concentration of the cathode circulation liquid (TAAH aqueous solution) circulating in the cathode side circulation line 15 on the cathode chamber 6 side reaches a predetermined concentration, the anode The electrolytic treatment of the circulating liquid (neutralizing treatment liquid) may be terminated, and the cathode circulating liquid (TAAH aqueous solution) may be recovered from the recovery line 18 of the cathode circulating liquid tank 8 as a high-purity product TAAH aqueous solution.

  Moreover, in 2nd invention of this application, after complete | finishing the electrolysis process in the said electrolysis process, after collect | recovering product TAAH aqueous solution from the cathode circulation liquid tank 9 of the electrolytic cell 2, inside the anode circulation liquid tank 8 of the electrolytic cell 2 Without removing the residual anolyte remaining in the anode, a new anolyte circulatory solution is prepared using the anolyte residue in the anolyte circulatory fluid tank 8, and the anolyte circulatory liquid is electrolyzed again to obtain the cathode circulatory liquid tank 9 The electrolytic treatment for recovering the TAAH aqueous solution from the product is repeated a plurality of times. At this time, the concentrated neutralization treatment obtained by concentrating the residual anolyte in the anodic circulating fluid tank 8 with the evaporative concentrator 3. A new anodic circulating liquid is prepared by adding a predetermined amount of the liquid, and a new cathodic circulating liquid (high purity and low concentration TAAH aqueous solution) is introduced into the cathodic circulating liquid tank 9, and the anodic circulating liquid is again introduced. Electrolyze.

  The number of repetitions of the electrolytic treatment carried out in the electrolysis step of the second invention depends on the initial turbidity of the neutralization treatment liquid and the concentrated neutralization treatment liquid used when preparing the anode circulating liquid, and at least Repeated twice or more. Also in the second aspect of the invention, when the electrolytic treatment is repeated a plurality of times, the product TAAH aqueous solution is not recovered from the cathode circulating liquid tank 9 for each electrolytic treatment, and the cathode in the cathode circulating tank 9 is recovered. After the electrolytic treatment is repeated a plurality of times until the circulating fluid reaches a desired TAAH concentration, the cathodic circulating fluid that reaches the desired TAAH concentration may be recovered as a product TAAH aqueous solution.

In carrying out the second aspect of the invention, the anode circulation prepared in the anode circulation liquid tank 8 is adjusted by adjusting the TAAC concentration of the concentrated neutralization treatment liquid obtained by concentration in the evaporation concentrator 3. The TAAC concentration of the liquid is maintained within the range of 18 to 30% by mass, and if necessary, part or all of the concentrated neutralized liquid, preferably 20% by mass to 80% by mass of the concentrated neutralized liquid. Preferably, the turbidity (JIS K0101) of the anodic circulating fluid prepared in the anodic circulating fluid tank 8 is adjusted by filtering the turbidity of the concentrated neutralizing solution by filtration of 30% by mass to 70% by mass. The flow rate of the circulating anode fluid is adjusted to 1.5 × 10 ⁻³ m / sec. 25 × 10 ⁻³ m / sec. Maintain within the following ranges.

  In the present invention, the carbon dioxide gas discharged from the outlet side of the anode chamber 5 during the electrolytic treatment of the anode circulation liquid (neutralization treatment liquid) in the electrolysis step is preferably removed from the carbon dioxide recovery line 18. It is collected and introduced into the neutralization tank 1 through the carbon dioxide gas introduction line 11 and is brought into contact with the TAAH-containing waste liquid supplied into the neutralization tank 1 and used for neutralization of this TAAH-containing waste liquid. At this time, the amount of carbon dioxide discharged from the outlet side of the anode chamber 5 during the electrolytic treatment is not sufficient to neutralize the TAAH-containing waste liquid supplied into the neutralization tank 1. Replenishes the shortage of carbon dioxide introduced from the carbon dioxide introduction line 11.

  According to the TAAH-containing waste liquid regeneration method according to the first and second inventions of the present application described above, adhesion of tar-like substances derived from organic impurities in the TAAH-containing waste liquid to the positive electrode or cation exchange membrane of the electrolytic cell is prevented. It can be greatly reduced (prevention of electrolytic cell contamination), and the load on the filtration operation of the neutralization liquid introduced into the anode chamber side of the electrolytic cell can be greatly reduced (reduction of filtration load). A TAAH aqueous solution having a predetermined TAAH concentration and high purity can be recovered as a product from the cathode chamber side of the electrolytic cell (an improvement in the TAAH recovery rate).

[Example 1]
As a TAAH-containing waste liquid to be recycled, the photoresist development waste liquid is concentrated until the concentration of tetramethylammonium hydroxide (TMAH) is 14.7% by mass, and the organic impurity concentration is 898 mg per mol of TMAH as a resist amount. A photoresist developing waste solution (TMAH-containing waste solution) having an iron (Fe) concentration of 700 ppb was used.

  Further, in the neutralization step, carbon dioxide gas is blown into the TMAH-containing waste liquid to neutralize to pH 9.6, and by this neutralization treatment, the tetramethylammonium carbonate (TMAC) concentration (TMAC concentration) is 14 in terms of TMAH. 8% by mass, and the organic impurity concentration (resist amount) per mol of TMAH is 510 mg / mol, and the insolubilized impurities derived from the photoresist generated by this neutralization treatment are defined as turbidity (JIS K0101). A neutralization treatment solution (TMAC aqueous solution) containing 1028 ppm was obtained.

Next, in the electrolysis process, as an electrolytic cell used for the electrolysis treatment of the neutralization solution, a positive electrode made of an oxide film-coated titanium plate (area: 13.2 cm ² ) and a negative electrode made of nickel plate (area: 13.2 cm) and ^2), it is disposed between the positive electrode and the negative electrode anode chamber (volume: cross-sectional area 1.52 cm ² × length 6.97cm = 10.6cm ³⁾ and cathode chamber (volume: cross-sectional area 1.52 cm ² × length 6.97 cm = 10.6 cm ³ ) and a cation exchange membrane (DuPont product name: Nafion 324), and the anode chamber is equipped with an anode circulating liquid tank (volume: 2000 cm ³ ), and the cathode A laboratory electrolytic cell equipped with a cathode circulation liquid tank (volume: 2000 cm ³ ) was used on the chamber side.

The anode circulating liquid tank on the anode chamber side of this electrolytic cell is filled with 1080 ml of the neutralized liquid obtained above as the anode circulating liquid, and the cathode circulating liquid tank on the cathode chamber side is 6.8 ml as the cathode circulating liquid. 705 ml of mass% TMAH aqueous solution is added, and the circulation rate of the anode circulation solution (neutralization solution) on the anode chamber side and the circulation rate of the cathode circulation solution (TMAH aqueous solution) on the cathode chamber side are respectively flow rates (linear velocity). A constant current voltage of 0.15 A / cm ² DC (starting voltage: 17.0 V and maximum voltage: 17.0 V) was applied between the positive electrode and the negative electrode, 23.7 × 10 ⁻³ m / sec. Moreover, the neutralization solution was subjected to electrolytic treatment so that the temperature was 35 ° C.

  After completion of the electrolysis of the neutralization solution in this electrolysis process, the circulation of the anode circulation solution and the cathode circulation station is stopped, and the product TMAH aqueous solution regenerated from the cathode circulation solution tank on the cathode chamber side (cathode circulation solution) Collect 905 ml and measure its TMAH concentration, organic impurity concentration (resist amount), iron (Fe) concentration as metal impurity, and insolubilized impurity concentration (turbidity: JIS K0101), and TMAH content in TMAH-containing waste liquid Calculate the TMAH recovery rate (wt%) by calculating the ratio of TMAH content in the product TMAH aqueous solution to the amount, and remove the positive electrode of the electrolyzer after electrolytic treatment, and the adhesion of tar-like substances to this positive electrode (Contamination state of electrode plate) was visually observed and evaluated in three stages: ○: no adhesion, Δ: slight adhesion on the outer periphery, and x: adhesion on the entire surface.

  As shown in Table 1, the adhesion of tar-like substances to the positive electrode was not observed, and the product TMAH aqueous solution obtained from the cathode chamber side had a TMAH concentration of 16.5% by mass and was organic. The impurity concentration (resist amount) was 1.1 mg / mol, and the iron (Fe) concentration was 3.0 ppm. Further, the recovery rate of TMAH was 35.6 wt%, and the concentration of insolubilized impurities was less than 1 ppm and was not detected. In addition, the turbidity (JIS K0101) of the anode circulating liquid (residual anolyte) after electrolysis was increased to 1800 ppm.

[Example 2]
The same photoresist development waste liquid as that used in Example 1 was used as the TAAH-containing waste liquid, and the flow rate (linear velocity) of the neutralization treatment liquid (anode circulation liquid) on the anode chamber side was 2.63 × 10 ⁻³ m / The TAAH-containing waste liquid was regenerated in the same manner as in Example 1 except that the second was used.
The results are shown in Table 1.

Example 3
The same photoresist development waste liquid as used in Example 1 was used as the TAAH-containing waste liquid, and the flow rate (linear velocity) of the neutralization treatment liquid (anode circulation liquid) on the anode chamber side was 1.54 × 10 ⁻³ m / sec. A TAAH-containing waste liquid was regenerated in the same manner as in Example 1 except that.
The results are shown in Table 1.

Example 4
As a TAAH-containing waste liquid to be recycled, the photoresist development waste liquid is concentrated until the tetramethylammonium hydroxide (TMAH) concentration is 28.4% by mass, and the organic impurity concentration is 898 mg / mol. Using the waste liquid (TMAH-containing waste liquid), the TMAH-containing waste liquid is neutralized by blowing carbon dioxide into the TMAH-containing waste liquid. By this neutralization treatment, the TMAC concentration (TMAH conversion) is 27.2% by mass, A neutralized solution (TMAC aqueous solution) having an organic impurity concentration of 520 mg / mol per mol of TMAH and an insolubilized impurity concentration (turbidity: JIS K0101) of 2600 ppm was obtained.

This neutralization treatment solution (TMAC aqueous solution) was used as the anode circulation solution, and 5.2% by mass of TMAH aqueous solution was used as the cathode circulation solution. Further, the neutralization treatment solution (anode circulation solution) on the anode chamber side The TAAH-containing waste liquid was regenerated in the same manner as in Example 1 except that the flow rate (linear velocity) was 2.19 × 10 ⁻³ m / sec.
The results are shown in Table 1.

[Comparative Example 1]
The same photoresist development waste liquid as used in Example 1 was used as the TAAH-containing waste liquid, and the flow rate (linear velocity) of the neutralization treatment liquid (anode circulation liquid) on the anode chamber side was 1.21 × 10 ⁻³ m / sec. A TAAH-containing waste liquid was regenerated in the same manner as in Example 1 except that.
The results are shown in Table 1.

[Comparative Example 2]
The same photoresist development waste liquid as used in Example 1 was used as the TAAH-containing waste liquid, and the flow rate (linear velocity) of the neutralization treatment liquid (anode circulation liquid) on the anode chamber side was 1.02 × 10 ⁻³ m / sec. A TAAH-containing waste liquid was regenerated in the same manner as in Example 1 except that.
The results are shown in Table 1.

[Comparative Example 3]
A neutralization treatment solution [TMAC concentration (converted to TMAH): 14.8 wt%; turbidity: 1028] obtained by carrying out the neutralization treatment in the same manner as in Example 1 was applied to a 0.25 μm hollow fiber filter (Asahi Kasei Corporation). (Trade name: Microza PMP-003) using a cross flow filtration (80% recovery), and the tetramethylammonium carbonate (TMAC) concentration (TMAC concentration) is 14.5 wt% in terms of TMAH. A neutralization treatment solution (TMAC aqueous solution) having an insolubilizing impurity concentration (turbidity: JIS K0101) of 5400 ppm was prepared.
This neutralization solution (TMAC aqueous solution) was used as the anode circulation solution, and the flow rate (linear velocity) of the neutralization treatment solution (anode circulation solution) on the anode chamber side was 2.20 × 10 ⁻³ m / sec. In the same manner as in Example 1, the TAAH-containing waste liquid was regenerated.
The results are shown in Table 1.

Example 5
A neutralization treatment solution [TMAC concentration (converted to TMAH): 14.8 wt%; turbidity: 1028] obtained by carrying out the neutralization treatment in the same manner as in Example 1 was applied to a 0.25 μm hollow fiber filter (Asahi Kasei Corporation). (Product name: Microza PMP-003) is filtered by cross-flow filtration (80% recovery), insoluble impurities are removed to turbidity (JIS K0101) <1 ppm, and then vacuum distillation (200 mmHg) is performed. A concentrated neutralization solution A after filtration having a TMAC concentration (TMAH conversion) of 40.4% by mass was prepared. The concentrated neutralization solution A after filtration had an organic impurity concentration (resist amount: mg / mol) per mol of TMAH of 760 mg / mol and an insolubilized impurity concentration (turbidity: JIS K0101) of 16 ppm. .

  Further, the TMAC concentration was obtained by distillation under reduced pressure (200 mmHg) of a neutralization treatment solution [TMAC concentration (TMAH conversion): 14.8 wt%; turbidity: 1028] obtained by carrying out the neutralization treatment in the same manner as in Example 1 above. (TMAH conversion) is 44.2% by mass, organic impurity concentration (resist amount) is 750 mg / mol, and insoluble impurity concentration (turbidity: JIS K0101) is 3260 ppm. Treatment liquid B was obtained.

  Further, the concentrated neutralization treatment liquid A after filtration and the unfiltered concentration neutralization treatment liquid B are mixed at a ratio of 1: 1, the TMAC concentration (TMAH conversion) is 42.2% by mass, and TMAH A concentrated neutralization treatment solution having an organic impurity concentration (resist amount) per mol of 755 mg / mol and an insolubilized impurity concentration (turbidity: JIS K0101) of 1620 ppm is prepared, and then this concentration neutralization is performed. 325 ml of water was added to 656 ml of the treatment solution for dilution to prepare a TMAC aqueous solution with a TMAC concentration (TMAH conversion) of 27.0% by mass and an insolubilized impurity concentration (turbidity: JIS K0101) of 1060 ppm. This TMAC aqueous solution was used as the anodic circulating liquid used in the first electrolytic treatment of the electrolysis process.

Using the same electrolytic cell as in Example 1 above, 1000 mL of the anode circulating liquid obtained above was placed in the anode circulating liquid tank on the anode chamber side of this electrolytic tank, and in the cathode circulating liquid tank on the cathode chamber side. As a cathode circulation liquid, 1000 ml of a TMAH aqueous solution having a TMAH concentration of 7.1% by mass is added, and the circulation speed of the anode circulation liquid on the anode chamber side and the circulation speed of the cathode circulation liquid on the cathode chamber side are respectively flow rates (linear velocity). The first electrolytic treatment (starting voltage: 14.2 V and maximum voltage: 15.8 V) was performed in the same manner as in Example 1 above, at 0 × 10 ⁻³ m / sec.

After the completion of the first electrolytic treatment, 1200 ml of a regenerated TMAH aqueous solution (cathode circulating solution) was obtained in the cathode circulating solution tank on the cathode chamber side.
750 ml of the cathode circulation liquid in the cathode circulation liquid tank was recovered as a product TMAH aqueous solution, and the state of contamination of the electrode plate after the completion of the electrolytic treatment was examined in the same manner as in Example 1, and the product TMAH recovered from the cathode chamber side. TMAH concentration of aqueous solution (cathode circulating solution), organic impurity concentration (resist amount) per mol of TMAH, and iron (Fe) concentration are measured, and residual anode circulation remaining in the anode circulation solution tank on the anode chamber side The TMAC concentration (TMAH conversion) and turbidity (JIS K0101) of the liquid were measured. The results are shown in Table 2.

(Second electrolytic treatment)
Next, in the anode circulation liquid tank on the anode chamber side, 410 ml of the concentrated neutralization treatment liquid is added to the remaining anode circulation liquid remaining in the anode circulation liquid tank to adjust the total to 1000 ml, and the second electrolytic treatment. In the cathode circulation liquid tank on the cathode chamber side, 550 ml of pure water was added to 450 ml of the remaining TMAH aqueous solution (cathode circulation liquid) to make a total of 1000 ml of cathode. Except for the circulating fluid (TMAH concentration: 6.8% by mass), the electrolytic treatment was carried out under the same conditions as in the first electrolytic treatment described above (starting voltage and maximum voltage are shown in Table 1). A 1200 ml TMAH aqueous solution (cathode circulating liquid) regenerated in the cathode circulating liquid tank on the side was obtained.

  After the completion of the second electrolytic treatment, 750 ml of the cathode circulating liquid in the cathode circulating liquid tank was recovered as a product TMAH aqueous solution in the same manner as in the first time, and the state of contamination of the electrode plate after the electrolytic treatment was completed in Example 1. The TMAH concentration of the product TMAH aqueous solution (cathode circulating solution) recovered from the cathode chamber side, the organic impurity concentration (resist amount) per mol of TMAH, and the iron (Fe) concentration are measured. Then, the TMAC concentration (TMAH conversion) and turbidity (JIS K0101) of the remaining anode circulating liquid remaining in the anode circulating liquid tank on the anode chamber side were measured. The results are shown in Table 2.

(3rd-8th electrolytic treatment)
Further, the anode circulating solution and the cathode circulating solution shown in Table 1 were prepared in the same manner as in the second electrolytic treatment, and the same conditions (starting voltage and voltage as in the first electrolytic treatment) were prepared. The maximum value is shown in Table 1.) Electrolytic treatment is performed, and the state of contamination of the electrode plate after completion of the electrolytic treatment is examined in the same manner as in Example 1, and in the cathode circulation liquid tank as in the second time. Part of the cathode circulation liquid (750 ml) is recovered as a product TMAH aqueous solution, the TMAH concentration of the recovered product TMAH aqueous solution (cathode circulation liquid), the organic impurity concentration (resist amount) per mol of TMAH, and iron (Fe) The concentration was measured, and the TMAC concentration (TMAH conversion) and turbidity (JIS K0101) of the residual anode circulating liquid remaining in the anode circulating liquid tank on the anode chamber side were measured. Moreover, about the product TMAH aqueous solution obtained by 1-7 times of electrolytic treatment, the recovery rate (cumulative TMAH recovery rate) with respect to the TMAH amount in the TMAH containing waste liquid of the total TMAH amount was obtained. The results are shown in Table 2.

Example 6
Using the concentrated neutralization solution A after filtration prepared in Example 5 as the concentrated neutralization solution, 375 ml of water was added to 625 ml of the concentrated neutralization solution to dilute, and the TMAC concentration (TMAH conversion) was 24. A TMAC aqueous solution having a concentration of 1% by mass and an insolubilizing impurity concentration (turbidity: JIS K0101) of 11 ppm was prepared, and this TMAC aqueous solution was used as an anodic circulating fluid used in the first electrolytic treatment of the electrolysis process.

  In the same manner as in Example 5, a concentrated neutralization treatment liquid, an anode circulation liquid, and a cathode circulation liquid were prepared, and the first to ninth electrolytic treatments were performed under the conditions shown in Table 2. The same as in Example 5 The contamination status of the electrode plate, the TMAH concentration of the product TMAH aqueous solution (cathode circulating solution), the organic impurity concentration (resist amount) per mol of TMAH, the iron (Fe) concentration, and the TMAC concentration of residual anode circulating solution ( TMAH conversion) and turbidity (JIS K0101) and 1 to 8 cumulative TMAH recoveries were determined. The results are shown in Table 2.

[Examples 7 to 9]
Using the unfiltered concentrated neutralized solution B prepared in Example 5 above as the concentrated neutralized solution, the concentrated neutralized solution of the addition amount shown in Table 4 was diluted with water to 1000 ml, and the TMAC shown in Table 4 was used. A TMAC aqueous solution having a concentration (in terms of TMAH) and an insolubilized impurity concentration (turbidity: JIS K0101) was prepared, and this TMAC aqueous solution was used as an anodic circulating liquid used in the first electrolytic treatment of the electrolysis step.

  Concentrated neutralization treatment liquid, anode circulation liquid, and cathode circulation liquid were prepared in the same manner as in Example 5, and the first to third electrolytic treatments were performed under the conditions shown in Table 4, and the same as in Example 5 The contamination status of the electrode plate, the TMAH concentration of the product TMAH aqueous solution (cathode circulating solution), the organic impurity concentration (resist amount) per mol of TMAH, the iron (Fe) concentration, and the TMAC concentration of residual anode circulating solution ( TMAH conversion) and turbidity (JIS K0101) and the cumulative TMAH recovery rate of 1 to 2 times were determined. The results are shown in Table 4.

  DESCRIPTION OF SYMBOLS 1 ... Neutralization tank, 2 ... Electrolysis cell, 3 ... Evaporative concentrator, 4 ... Cation exchange membrane, 5 ... Anode chamber, 6 ... Cathode chamber, 5a ... Anode, 6a ... Cathode, 7 ... DC power supply, 8 ... Anode Circulating fluid tank, 9 ... Cathode circulating fluid tank, 10 ... Waste liquid introduction line, 11 ... Carbon dioxide gas introduction line, 12, 13 ... Transfer line, 14 ... Anode side circulation line, 15 ... Cathode side circulation line, 16 ... Liquid feed pump 17 ... Extraction line, 18 ... Recovery line, 19 ... Carbon dioxide recovery line, 20 ... Cathode circulating fluid preparation line, 21 ... Exhaust line.

Claims (8)

Carbonate gas was blown into a TAAH-containing waste liquid containing tetraalkylammonium hydroxide (TAAH) and organic impurities, and the neutralization process for neutralizing the tetraalkylammonium hydroxide in the TAAH-containing waste liquid was generated in this neutralization process. By introducing a neutralization treatment solution containing tetraalkylammonium carbonate (TAAC) into the anode chamber side of an electrolytic cell partitioned into an anode chamber and a cathode chamber by a cation exchange membrane, and performing electrolysis of the TAAC An electrolysis step of recovering the purified TAAH aqueous solution from the cathode chamber side,
In the electrolysis step, the neutralization treatment liquid introduced into the anode chamber is circulated as an anode circulation liquid on the anode chamber side, and a TAAH aqueous solution having a lower concentration than the TAAH aqueous solution collected from the cathode chamber is circulated on the cathode chamber side. Circulating as a cathode circulation liquid, removing organic impurities from the TAAH-containing waste liquid to recover a high-purity product TAAH aqueous solution, a method for treating a tetraalkylammonium hydroxide-containing waste liquid,
While controlling the turbidity (JIS K0101) of the neutralization treatment liquid obtained in the neutralization step and introduced into the anode chamber side of the electrolytic cell in the electrolysis step to 5000 ppm or less,
In the electrolysis step, the flow rate (linear velocity) of the anode circulating liquid circulating in the anode chamber is maintained within a range of 1.5 × 10 ^{−3 to} 25 × 10 ⁻³ m / sec,
A method for reclaiming a tetraalkylammonium hydroxide-containing waste liquid, wherein a cathode circulating liquid having a TAAH concentration of 15 to 30% by mass is recovered as a product TAAH aqueous solution from the cathode chamber side of the electrolytic cell.   The regeneration treatment method for a tetraalkylammonium hydroxide-containing waste liquid according to claim 1, wherein the turbidity (JIS K0101) of the neutralization treatment liquid introduced into the anode chamber side of the electrolytic cell in the electrolysis step is controlled to 3000 ppm or less. Carbonate gas was blown into a TAAH-containing waste liquid containing tetraalkylammonium hydroxide (TAAH) and organic impurities, and the neutralization process for neutralizing the tetraalkylammonium hydroxide in the TAAH-containing waste liquid was generated in this neutralization process. By introducing a neutralization treatment solution containing tetraalkylammonium carbonate (TAAC) into the anode chamber side of an electrolytic cell partitioned into an anode chamber and a cathode chamber by a cation exchange membrane, and performing electrolysis of the TAAC An electrolysis step of recovering the purified TAAH aqueous solution from the cathode chamber side,
In the electrolysis step, the neutralization treatment liquid introduced into the anode chamber is circulated as an anode circulation liquid on the anode chamber side, and a TAAH aqueous solution having a lower concentration than the TAAH aqueous solution collected from the cathode chamber is circulated on the cathode chamber side. Circulating as a cathode circulation liquid, removing organic impurities from the TAAH-containing waste liquid to recover a high-purity product TAAH aqueous solution, a method for treating a tetraalkylammonium hydroxide-containing waste liquid,
In the electrolysis step, after the electrolysis in the electrolysis step is completed and the product TAAH aqueous solution is recovered from the cathode chamber of the electrolytic cell, the neutralization solution is added to the residual anolyte remaining in the anode chamber of the electrolytic cell. An anodic circulating fluid is prepared, electrolysis of the obtained anodic circulating fluid is performed, and the electrolytic treatment for recovering the purified TAAH aqueous solution from the cathode chamber side is repeated a plurality of times,
The turbidity (JIS K0101) of the neutralization solution obtained in the neutralization step and introduced into the anode chamber side of the electrolytic cell in the electrolysis step is controlled to 5000 ppm or less, and in the electrolytic chamber anode chamber. The turbidity (JIS K0101) of the anode circulating liquid before electrolytic treatment to be prepared is controlled to 5000 ppm or less,
In the electrolysis step, the TAAC concentration of the anode circulating liquid circulating in the anode chamber is maintained within a range of 18 to 30% by mass, and the flow rate (linear velocity) of the anode circulating liquid is 1.5 × 10 ^{−3 to} 25 ×. The tetraalkyl hydroxide is maintained within a range of 10 ⁻³ m / sec, and the cathode circulating solution having a TAAH concentration of 15 to 30% by mass is recovered as a product TAAH aqueous solution from the cathode chamber side of the electrolytic cell. A method for recycling ammonium-containing waste liquid.   The electrolytic cell in the electrolysis step is provided with an anode circulating liquid tank that temporarily stores an anode circulating liquid circulating in the anode chamber, and a cathode circulating liquid that temporarily stores the cathode circulating liquid circulating in the cathode chamber The regeneration processing method of the tetraalkylammonium hydroxide containing waste liquid in any one of Claims 1-3 with which the tank is attached.   The tetraalkylammonium hydroxide-containing product according to any one of claims 1 to 4, wherein the turbidity of the neutralization treatment liquid introduced to the anode chamber side of the electrolytic cell in the electrolysis process is performed by filtration of the neutralization treatment liquid. Waste liquid recycling method.   The TAAC concentration of the anodic circulating liquid is maintained by adding a concentrated neutralizing treatment liquid obtained by concentrating the neutralizing liquid to a TAAC concentration of 40 to 50% by mass in the anodic circulating liquid. 5. A method for regenerating a waste liquid containing tetraalkylammonium hydroxide according to any one of 5 above.   The carbon dioxide gas discharged | emitted from the anode chamber of an electrolytic cell is collect | recovered, This collected carbon dioxide gas is introduce | transduced in the TAAH containing waste liquid of a neutralization process, and TAAH in a TAAH containing waste liquid is neutralized. A method for reclaiming a tetraalkylammonium hydroxide-containing waste liquid according to any one of the above.   The TAAH-containing waste liquid is a developing waste liquid of a photoresist developer, and the organic impurities in the TAAH-containing waste liquid are organic impurities derived from a photoresist. Waste liquid treatment method.

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