JP2015167922A - Electrodialyzer, electrodialysis method, and plating treatment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodialyzer with which predetermined ion components can be efficiently obtained from a plating liquid (e.g., electroless nickel plating solution) while removing unnecessary ion components, and also to provide an electrodialysis method and a plating treatment system using the electrodialyzer.SOLUTION: An intermediate chamber 4 provided between an anode chamber 2 in which an anode 20 is disposed and a cathode chamber 3 in which a cathode 30 is disposed includes a plurality of configurations comprising: a monovalent selective anion exchange membrane 11; a standard anion exchange membrane 12; a monovalent selective cation exchange membrane 13; a bipolar membrane 14; and four types of chamber frames 15-18 for distributing a predetermined solution to the monovalent selective anion exchange membrane 11, the standard anion exchange membrane 12, the monovalent selective cation exchange membrane 13, or the bipolar membrane 14. The monovalent selective anion exchange membrane 11, the standard anion exchange membrane 12, the monovalent selective cation exchange membrane 13, and the bipolar membrane 14 are arranged in this order, from the anode chamber 2 toward the cathode chamber 3. The configuration has four flow paths.

Description

The present invention relates to electrodialysis of a plating solution, for example, an electrodialysis apparatus for regenerating an electroless nickel plating solution containing hypophosphite ion (H ₂ PO ₂ ⁻ ) as a reducing agent, and the electrodialysis The present invention relates to an electrodialysis method using an apparatus and a plating system.

  Chemical nickel plating, which is a type of chemical plating, can be plated with metallic nickel without using electrodes, and features include plating on nonconductors, good corrosion resistance, and uniform plating film. It has the feature of. For this reason, chemical nickel plating imparts electrical conductivity to materials such as plastic, ceramic, and metal, improves the corrosion resistance, wear resistance or hardness of the material, and improves solderability or adhesion. It is widely used for such purposes.

By the way, in an electroless nickel plating solution containing hypophosphite ions (H ₂ PO ₂ ⁻ ) used as a reducing agent for chemical nickel plating, hypophosphite ions are oxidized and consumed each time they are used. . Oxidation of this hypophosphite ion generates phosphite ion (H ₂ PO ₃ ⁻ ). Further, in the electroless nickel plating solution, nickel ions (Ni ²⁺ ) are consumed every time they are used, so that nickel sulfate is replenished as needed for the purpose of replenishing nickel ions. As a result, sulfate ions (SO ₄ ²⁻ ) are accumulated in the plating solution. In yet an electroless nickel plating solution, hydroxide ions for the purpose or to adjust the pH of the supplemented with hypophosphorous acid ion or plating solution to be consumed by the use of the plating solution - necessary to appropriately replenish ^(OH) There is. At this time, counter ions (for example, sodium ions (Na ⁺ )) of the hydroxide ions are accumulated in the plating solution. Here, if hydroxide ions such as phosphite ions, sulfate ions, and sodium ions accumulate in the plating solution, these ions reduce the deposition rate of metallic nickel and reduce the decomposability of the plating solution. It becomes a deterioration factor such as increasing. For this reason, in order to use the plating solution stably for a long period of time, it is necessary to remove ions (inhibitory ions) that degrade the plating solution as needed.

  Conventionally, an electrodialysis method has been proposed to remove the inhibitory ions, and a specific example thereof is the method described in Patent Document 1. However, the method of Patent Document 1 has a large economic loss because many effective ions such as hypophosphite ions and nickel ions, which are ions to be included in the plating solution, are lost simultaneously with the removal of the inhibitory ions. In recent years, nickel and phosphorus ores used in preparing plating solutions have soared against the background of resource depletion. Under these circumstances, it has been required to reduce the loss of effective ions when using electrodialysis.

  Here, as a method considered to satisfy the above requirements, a two-stage electrodialysis method has been proposed in which at least two electrodialyzers are prepared and used in combination.

Patent Document 2 proposes a method of treating a plating solution using two or more electrodialyzers including an auxiliary electrodialyzer. Here, the processing method proposed in Patent Document 2 includes the following steps (a1) to (a3).
(A1) Primary electrodialysis is performed in a desalting chamber of the first electrodialysis tank equipped with a cation exchange membrane and an anion exchange membrane to obtain a concentrated solution of phosphorous acid H ₂ PO ₃ ⁻ , A step of repeatedly performing auxiliary electrodialysis until the concentration of nickel ions is less than 1.5 g / L.
(A2) A step of adjusting the pH of the concentrate having a nickel ion concentration of less than 1.5 g / L to 6 to 10.
(A3) After the step (a2), secondary electrodialysis is carried out in a desalting chamber of a second electrodialysis tank equipped with a monovalent selective cation exchange membrane and a monovalent selective anion exchange membrane. The process of collect | recovering the hypophosphite ion and organic acid which isolate | separated into the salt solution and the concentrate and moved to the concentrate by primary dialysis.

Also in Patent Document 3, as in Patent Document 2, an electrodialysis method using at least two electrodialysis apparatuses is proposed. Here, the method proposed in Patent Document 3 is a method of connecting a concentration chamber of a predetermined electrodialyzer and a desalting chamber of another electrodialyzer. For example, a second electrodialysis apparatus is formed by connecting a concentration chamber of a first electrodialysis apparatus (first electrodialysis apparatus) and a desalting chamber of a second electrodialysis apparatus (second electrodialysis apparatus). And the desalination chamber of the first electrodialyzer. According to Patent Document 3, an anion exchange membrane (first anion exchange membrane) and a cation exchange membrane (first cation exchange membrane) are alternately arranged in the first electrodialysis apparatus. . Here, the first anion exchange membrane is an anion exchange membrane that transmits a part of anions such as monovalent hypophosphite ions, phosphite ions, divalent sulfate ions, and organic acids. On the other hand, the first cation exchange membrane is a cation exchange membrane that transmits monovalent ions (such as sodium ions) but does not transmit divalent nickel ions (Ni ²⁺ ). Further, according to Patent Document 3, an anion exchange membrane (second anion exchange membrane) and a cation exchange membrane (second cation exchange membrane) are alternately arranged in the second electrodialysis apparatus. . Here, the second anion exchange membrane is an anion exchange membrane that permeates monovalent hypophosphite ions and organic acids and does not permeate divalent phosphite ions and sulfate ions. On the other hand, the second cation exchange membrane is a cation exchange membrane having a hydrogen selection performance that transmits hydrogen ions but does not transmit other cations (for example, sodium ions). In Patent Document 3, the interior of the desalting chamber of the second electrodialyzer is adjusted to be weakly alkaline (PH = 8.5), and monovalent phosphorous acid contained in the desalting chamber of the second electrodialyzer. Ions are converted to divalent phosphite ions.

JP 63-303078 A JP 2004-52029 A JP 2007-291465 A

  Here, according to the method proposed in Patent Document 2, the recovery rate of hypophosphite ions and anionic species of organic acids is improved by the effect of two-stage dialysis. However, it is difficult to improve the recovery rate of nickel ions, which are cations, even if the above two-stage dialysis is used. For this reason, it is necessary to reduce the loss by performing the first stage dialysis treatment a plurality of times. As described above, the electrodialysis method using a plurality of electrodialyzers including the auxiliary dialysis treatment proposed in Patent Document 2 has a problem that it is complicated and requires new equipment costs. At the same time, the counter ion of hydroxide ions such as sodium ions, which is one of the reaction inhibiting factors removed in the first stage dialysis treatment, returns to the electroless nickel plating solution again in the second stage dialysis treatment. There was also a problem.

  On the other hand, in the method proposed in Patent Document 3, two-stage dialysis performed using two electrodialyzers, ion dialysis membranes (valence selection membranes) arranged in each electrodialyzer, Thus, the recovery rate of hypophosphite ions, organic acids, and nickel ions is improved. However, when the cation to be removed is sodium ion, the hydrogen selection performance of the second cation exchange membrane was insufficient. For this reason, there was a problem that sodium ions separated from the plating solution in the first electrodialyzer returned to the plating solution again.

  As described above, in the method of performing two-stage dialysis using two or more electrodialyzers, the recovery efficiency of anions such as hypophosphite ions and organic acids and cations of nickel ions is improved. The removal efficiency of unnecessary cations such as sodium ions was insufficient. At the same time, since it is necessary to prepare a plurality of electrodialysis apparatuses, there is a problem that the entire apparatus is expensive and complicated processing is required when the apparatus is used.

  Furthermore, in any of Patent Documents 1 to 3, when converting monovalent phosphite ions to divalent phosphite ions, it is necessary to adjust the pH of the solution to at least weak alkalinity (pH ≧ 8.5). There is. For this reason, it was necessary to add an alkali solution such as an NaOH solution as appropriate. In addition, when the electrodialysis method is used, the pH of the electroless nickel plating solution is lowered by the dialysis treatment. Therefore, it is necessary to adjust the pH beforehand using an alkaline solution when using the plating solution after the dialysis treatment. .

  As described above, in the conventional electrodialysis apparatus, when removing or recovering a predetermined ion component from the plating solution, a very complicated adjustment process is required to increase the efficiency.

  The present invention relates to an electrodialyzer for efficiently obtaining a predetermined ionic component while removing an unnecessary ionic component from a plating solution (for example, an electroless nickel plating solution), an electrodialysis method using the electrodialyzer, and plating. An object is to provide a processing system.

  The present invention is an electrodialysis apparatus for an electroless plating solution characterized in that an intermediate chamber provided between an anode and a cathode and defined by an anion exchange membrane and a cation exchange membrane is partitioned by a bipolar membrane.

  Further, another electrodialysis apparatus of the present invention comprises an anode chamber in which an anode is disposed, a cathode chamber in which a cathode is disposed, and an intermediate chamber provided between the anode chamber and the cathode chamber. In the electrodialysis apparatus, wherein the ion exchange membrane is disposed between the anode chamber and the intermediate chamber, between the cathode chamber and the intermediate chamber, and in the intermediate chamber, the intermediate chamber has 1 Valence selective anion exchange membrane, standard anion exchange membrane, monovalent selective cation exchange membrane, bipolar membrane, monovalent selective anion exchange membrane, standard anion exchange membrane, monovalent selective cation exchange membrane Or a plurality of four types of chamber frames for distributing a predetermined solution to the bipolar membrane, the monovalent selective anion exchange membrane, the standard anion exchange membrane, and the monovalent selective cation exchange. Membrane and said bipolar However, from the anode chamber toward the cathode chamber, the monovalent selective anion exchange membrane, the standard anion exchange membrane, the monovalent selective cation exchange membrane and the bipolar membrane are arranged in this order, and the configuration is as follows: It has four flow paths.

  According to the present invention, the efficiency of removal and recovery of predetermined ion components contained in the plating solution can be significantly improved.

It is a schematic diagram which shows the example of embodiment in the electrodialysis apparatus of this invention. It is a figure which shows the behavior of the ion in the predetermined | prescribed room | chamber in the electrodialysis apparatus of FIG. 1, (a) is a figure which shows the behavior of the ion in an intermediate | middle chamber, (b) is the behavior of the ion in the anode chamber vicinity. (C) is a figure which shows the behavior of the ion in the cathode chamber vicinity. (A) is a cross-sectional schematic diagram which shows the structure of a bipolar film, (b) is the schematic which shows the characteristic of a bipolar film. 2 is a schematic diagram showing an electrodialysis apparatus used in Comparative Example 1. FIG.

  An electrodialysis apparatus according to an embodiment of the present invention has a structure in which an intermediate chamber defined by an anion exchange membrane and a cation exchange membrane is provided between an anode and a cathode, and the intermediate chamber is partitioned by a bipolar membrane. . As one form of the electrodialysis apparatus of the present invention, for example, an anode chamber in which an anode is disposed, a cathode chamber in which a cathode is disposed, and an intermediate chamber provided between the anode chamber and the cathode chamber, Have. Further, in this electrodialysis apparatus, ion exchange membranes are arranged between the anode chamber and the intermediate chamber, between the cathode chamber and the intermediate chamber, and in the intermediate chamber, respectively.

  In the electrodialysis apparatus according to one embodiment of the present invention, for example, the intermediate chamber has a plurality of configurations including four types of ion exchange membranes and four types of chamber frames. Here, the four types of ion exchange membranes are specifically a monovalent selective anion exchange membrane, a standard anion exchange membrane, a monovalent selective cation exchange membrane and a bipolar membrane. The chamber membrane distributes a predetermined solution to any of the four types of ion exchange membranes described above (monovalent selective anion exchange membrane, standard anion exchange membrane, monovalent selective cation exchange membrane, and bipolar membrane). Is provided to do. In the present embodiment, the intermediate chamber is a unit composed of a plurality of ion exchange membranes and a plurality of chamber frames, and the shape thereof is not particularly limited. The chamber frame is a member provided between the ion exchange membrane and the ion exchange membrane.

  In the present invention, for example, four types of ion exchange membranes provided in the intermediate chamber are arranged according to a predetermined rule. Specifically, a monovalent selective anion exchange membrane, a standard anion exchange membrane, a monovalent selective cation exchange membrane, and a bipolar membrane are arranged in this order from the anode chamber to the cathode chamber.

  In the present invention, for example, the above-described configuration (a configuration including four types of ion exchange membranes and four types of chamber frames) has four flow paths. In the present invention, for example, the n flow channel (n is a natural number) means that the number of types of fluid flowing through the plurality of chamber frames of the electrodialysis apparatus is n. That is, in the present invention, for example, it means that there are four types of fluid flowing through an arbitrary chamber frame (excluding a chamber frame corresponding to an anode chamber or a cathode chamber).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments described below.

  FIG. 1 is a schematic diagram showing an example of an embodiment of the electrodialysis apparatus of the present invention. The electrodialysis apparatus 1 of FIG. 1 includes an anode chamber 2 having an anode 20, a cathode chamber 3 having a cathode 30, and an intermediate chamber 4 between the anode chamber 2 and the cathode chamber 3. In the present embodiment, the shape of the anode chamber 2 and the cathode chamber 3 is not limited to a shape having a three-dimensional space having a length, a height, and a depth, and has the same shape as the above-described chamber frame. There may be.

  In the electrodialysis apparatus 1 of FIG. 1, a standard cation exchange membrane 10 is provided between the anode chamber 2 and the intermediate chamber 4. That is, the standard cation exchange membrane 10 provided between the anode chamber 2 and the intermediate chamber 4 is a member that partitions the anode chamber 2 and the intermediate chamber 4. In the electrodialysis apparatus 1 of FIG. 1, a standard cation exchange membrane 10 is provided between the cathode chamber 3 and the intermediate chamber 4. That is, the standard cation exchange membrane 10 provided between the cathode chamber 3 and the intermediate chamber 4 is a member that partitions the cathode chamber 3 and the intermediate chamber 4.

The intermediate chamber 4 in the electrodialysis apparatus 1 of FIG. 1 includes a recovery liquid chamber frame 15, a monovalent selective anion exchange membrane 11, a waste liquid chamber frame 16, a standard anion exchange membrane 12, a plating solution chamber frame 17, and a monovalent selection. A plurality of structures comprising the neutral cation exchange membrane 13, the NaOH liquid chamber frame 15, and the bipolar membrane 14. As shown in FIG. 1, the configuration comprising four types of ion exchange membranes (11, 12, 13, 14) and four types of chamber frames (15, 16, 17, 18) A plurality are arranged. In addition, the arrangement order of the four types of ion exchange membranes (11, 12, 13, 14) and the four types of chamber frames (15, 16, 17, 18) arranged in the intermediate chamber 4 is determined. Are arranged in the order shown below.
(Anode chamber 2 /.../) Recovery liquid chamber frame 15/1 monovalent selective anion exchange membrane 11 / waste liquid chamber frame 16 / standard anion exchange membrane 12 / plating liquid chamber frame 17/1 monovalent selective cation exchange membrane 13 / NaOH solution chamber frame 15 / bipolar membrane 14 (/... / Cathode chamber 3)

  1 is a tank for storing a predetermined solution, specifically, a recovery liquid tank 5, a waste liquid tank 6, a plating liquid tank 7, a NaOH liquid tank 8, an anode tank 21, and a cathode tank. 31. In the electrodialysis apparatus 1 of FIG. 1, the solutions respectively stored in these tanks are circulated between the tank and the chamber or the chamber frame by a predetermined liquid circulation system.

  Specifically, the solution stored in the anode tank 21 is circulated between the anode tank 21 and the anode chamber 2 by the anolyte circulation system 22. The solution stored in the cathode chamber 31 is circulated between the cathode chamber 31 and the cathode chamber 3 by the catholyte circulation system 32.

  The used plating solution stored in the plating solution tank 7 is circulated between the plating solution tank 7 and the plating solution chamber frame 17 by a plating solution circulation system 47. The waste liquid stored in the waste liquid tank 16 is circulated between the waste liquid tank 6 and the waste liquid chamber frame 16 by the waste liquid circulation system 46. The recovered liquid stored in the recovered liquid tank 5 is circulated between the recovered liquid tank 5 and the recovered liquid chamber frame 15 by the recovered liquid circulation system 45. The NaOH solution (NaOH aqueous solution) stored in the NaOH solution tank 8 is circulated between the NaOH solution tank 8 and the NaOH solution chamber frame 18 by the NaOH solution circulation system 48. As described above, the electrodialysis apparatus 1 of FIG. 1 includes four types of circulatory systems in addition to the anolyte circulation system 22 and the catholyte circulation system 32. For this reason, the electrodialysis apparatus 1 of FIG. 1 has four flow paths (four flow paths).

On the other hand, the electrodialysis apparatus 1 of FIG. 1 is provided with the flow paths shown in the following (i) to (iv) in addition to the above-described flow path / liquid circulation system.
(I) A flow path 41 provided between the waste liquid tank 6 and the cathode tank 31 for transporting the solution stored in the cathode tank 31 to the waste liquid tank 6.
(Ii) A flow path 42 provided between the plating solution tank 7 and the cathode tank 31 for transporting the solution stored in the cathode tank 31 to the plating solution tank 7.
(Iii) A channel 43 provided between the NaOH solution tank 8 and the waste solution tank 6 for transporting the solution stored in the NaOH solution tank 8 to the waste solution tank 6.
(Iv) A flow path 44 provided between the plating solution tank 7 and the NaOH solution tank 8 for transporting the solution stored in the NaOH solution tank 8 to the plating solution tank 7.

  The details of the four types of flow paths (41, 42, 43, 44) will be described later. In addition, in the four-channel electrodialysis apparatus 1 of FIG. 1, a commercially available product (for example, DW1, 3, 5 type, manufactured by Asahi Glass Engineering Co., Ltd.) is used as a device for collecting the above-described components (chamber frame, ion exchange membrane, tank). Can be used.

Next, an electrodialysis method performed using the electrodialysis apparatus of this embodiment will be described. The electrodialysis method of this embodiment has at least the following process (a). Preferably, it further has one of the following processes (b) and (c). More preferably, it has all the following three processes (a) to (c).
(A) Voltage application process in which an electroless nickel plating solution is introduced into a plating solution chamber frame disposed between a standard anion exchange membrane and a monovalent selective cation exchange membrane, and a voltage is applied (b) a monovalent selective anion PH adjustment process in which hydroxide ions are introduced into the waste liquid chamber frame disposed between the exchange membrane and the standard anion exchange membrane to bring the pH in the waste liquid chamber frame to 8.5 or higher (c) Bipolar membrane and monovalent NaOH production process for producing NaOH in a NaOH liquid chamber frame placed between selective cation exchange membranes

  FIG. 2 is a diagram showing the behavior of ions in a predetermined chamber in the electrodialysis apparatus of FIG. 2A is a diagram showing the behavior of ions in the intermediate chamber, FIG. 2B is a diagram showing the behavior of ions in the vicinity of the anode chamber, and FIG. 2C is a diagram showing the cathode chamber. It is a figure which shows the behavior of the ion in the vicinity. Hereinafter, an electrodialysis method using the electrodialysis apparatus 1 of FIG. 1 will be described with reference to FIGS. 1 and 2 as an example of regeneration of an electroless nickel plating solution. However, the plating solution to which the present invention can be applied is not limited to the electroless nickel plating solution.

(Voltage application process)
The electroless nickel plating solution (used plating solution) whose composition has been changed and stored in the plating solution tank 7 is introduced into the plating solution chamber frame 17 via the plating solution circulation system 47. The electroless nickel plating solution whose composition has changed at this time includes hypophosphite ions (H ₂ PO ₂ ⁻ ), phosphite ions (H ₂ PO ₃ ⁻ ), and sulfate ions (SO ₄ ² ) as anions. ^- ) And are included. Here, hypophosphite ions are ions contained in the reducing agent introduced into the electroless nickel plating solution. Phosphite ion is an ion generated by oxidation of the reducing agent. Sulfate ion is an ion that exists as a counter ion of nickel ion (Ni ²⁺ ).

Here, the valences of hypophosphite ions, phosphite ions and sulfate ions contained in the electroless nickel plating solution whose composition has changed are monovalent, monovalent and divalent, respectively. Although phosphorous acid is a dibasic acid, it exists as a monovalent ion (H ₂ PO ₃ ⁻ ) because the electroless nickel plating solution has an acidic range of 4 to 5.

In addition to the above-described anions (H ₂ PO ₂ ⁻ , H ₂ PO ₃ ⁻ , SO ₄ ²⁻ ), the electroless nickel plating solution whose composition has changed includes cation nickel ions (Ni ²⁺ ). And sodium ions (Na ⁺ ). Here, the sodium ion is an ion that exists as a counter ion of hypophosphite ion or phosphite ion.

Here, when a current and a voltage are applied between the anode 20 and the cathode 30, the anions (H ₂ PO ₂ ⁻ , H contained in the electroless nickel plating solution having a changed composition introduced into the plating solution chamber frame 17. ₂ PO ₃ ⁻ , SO ₄ ²⁻ ) moves to the anode 20 side. Then, it passes through the standard anion exchange membrane 12 installed on the anode 20 side and moves to the waste liquid chamber frame 16. The amount of movement of each anion at this time is determined by the inherent movement coefficient of each ion with respect to the ion exchange membrane to be used regardless of the valence of the ions.

On the other hand, when an electric current is applied between the anode 20 and the cathode 30, cations (Ni ²⁺ , Na ⁺ ) contained in the electroless nickel plating solution having a changed composition introduced into the plating solution chamber frame 17 are: Move to the cathode 30 side. And it reaches | attains the monovalent | monohydric selective cation exchange membrane 13 installed in the cathode 30 side. Here, the monovalent selective cation exchange membrane 13 is a cation exchange membrane that has a property of permeating monovalent cations but hardly permeating non-monovalent cations. Of the cations that can exist in the plating solution chamber frame 17, monovalent cations are only sodium ions. Therefore, sodium ions permeate the monovalent selective cation exchange membrane 13 and move to the NaOH liquid chamber frame 18, but nickel ions that are not monovalent cations do not move to the NaOH liquid chamber frame 18 and move to the NaOH liquid chamber frame 18. Most of them stay in the plating solution chamber film 17. Note that the ratio between the passage of each cation and the block in the monovalent selective cation exchange membrane 13 is determined by the inherent transfer coefficient of the monovalent selective cation exchange membrane 13 used.

  The sodium ions that have moved to the NaOH liquid chamber frame 18 further move to the cathode 30 side and reach the bipolar membrane 14 (the anion exchange layer 14a) installed on the cathode 30 side. Here, since the anion exchange layer 14a does not permeate cations, sodium ions existing in the NaOH liquid chamber frame 18 reach the bipolar membrane 14, but do not permeate the bipolar membrane 14 and enter the NaOH chamber liquid frame 18. Stay.

In summary, the cations contained in the electroless nickel plating solution are divided into ions (Ni ²⁺ ) remaining in the plating solution chamber frame 17 and ions (Na ⁺ ) moving to the NaOH solution chamber frame 18. . In other words, sodium ions that are contained in the electroless nickel plating solution whose composition has changed and are unnecessary for the regenerated plating solution are removed from the plating solution.

(PH adjustment process)
By the way, the inside of the waste liquid chamber frame 16 is controlled to be alkaline. Here, in order to control the inside of the waste liquid chamber frame 16 to be alkaline, it is necessary to appropriately introduce an alkaline aqueous solution into the waste liquid chamber frame 16. Examples of the method of introducing the alkaline aqueous solution into the waste liquid chamber frame 16 include a method of introducing from the tank having the alkaline aqueous solution contained in the electrodialysis apparatus 1 and a method of introducing from an external system not included in the electrodialysis apparatus 1. However, it is not particularly limited. Preferably, an alkaline aqueous solution is introduced into the waste liquid layer 6 using any one of the flow path 41 and the flow path 43 shown in the above (i) and (iii). As described above, the reason why one of the flow path 41 and the flow path 43 in FIG. 1 is used is that the solutions respectively stored in the cathode tank 31 and the NaOH liquid tank 8 are alkaline NaOH aqueous solutions. In addition, the mechanism in which the NaOH aqueous solution is stored in the cathode tank 31 and the NaOH liquid tank 8 will be described in the NaOH generation process described later.

  As described above, the inside of the waste liquid chamber frame 16 is desirably controlled to be alkaline, but the term “alkaline” here means that the pH is preferably 8.5 or more. However, if the alkalinity is too strong, the waste liquid chamber frame 16 itself may be damaged. Therefore, the pH of the waste liquid chamber frame 16 is more preferably controlled to 8.5 or more and 10 or less. Here, as a method for controlling the inside of the waste liquid chamber frame 16 to be alkaline, for example, a pH control device 9 is installed in the vicinity of the waste liquid tank 6, and the flow path is referred to while referring to the pH value displayed on the pH control device 9. The NaOH aqueous solution is introduced into the waste liquid tank 6 by using either 41 or the flow path 43.

As described above, by controlling the inside of the waste liquid chamber frame 16 to be alkaline, phosphite ions are converted from monovalent ions (H ₂ PO ₃ ⁻ ) to divalent ions (HPO ₃ ²⁻ ). The Note that this conversion does not occur for hypophosphite ions (H ₂ PO ₂ ⁻ ).

By the way, the anion in the waste liquid chamber frame 16 reaches the monovalent selective anion exchange membrane 11 when a current is applied. Here, the monovalent selective anion exchange membrane 11 is an anion exchange membrane having a property of selectively transmitting a monovalent anion but hardly transmitting a non-monovalent anion. Here, among the anions that may exist in the waste liquid chamber frame 16, the monovalent anions are only hypophosphite ions. Therefore, hypophosphite ions permeate the monovalent selective anion exchange membrane 11 and move to the recovery chamber frame 15, while other anions (HPO ₃ ²⁻ , SO ₄ ²⁻ ) move in the recovery chamber frame. 15, and most of them stay in the waste liquid chamber frame 16. The ratio between the passage of each anion and the block in the monovalent selective anion exchange membrane 11 is determined by the intrinsic transfer coefficient of the monovalent selective anion exchange membrane 11 used.

  The hypophosphite ions that have moved to the recovery liquid chamber frame 15 further move to the anode 20 side and reach the bipolar membrane 14 installed on the anode 20 side. Here, hypophosphite ions existing in the recovery liquid chamber frame 15 reach the bipolar membrane 14 but stay in the recovery liquid chamber frame 15 without passing through the bipolar membrane 14.

  FIG. 3A is a schematic cross-sectional view showing the structure of the bipolar film, and FIG. 3B is a schematic view showing the characteristics of the bipolar film. As shown in FIG. 3A, the bipolar membrane 14 is an ion exchange membrane formed by laminating an anion exchange layer 14a and a cation exchange layer 14b. In the electrodialysis apparatus 1 of FIG. 1, the installation mode of the bipolar membrane 14 is not particularly limited, but preferably, the anion exchange membrane 14a is disposed on the anode side (anode 20 side) and the cation exchange membrane on the cathode side (cathode 30 side). 14b is arranged. When the bipolar membrane 14 is thus installed, hypophosphite ions that have moved to the recovery chamber frame 15 approach the cation exchange membrane 14b. Here, since the cation exchange membrane 14 b does not transmit anions, hypophosphite ions stay in the recovery liquid chamber frame 15.

In summary, the anions contained in the electroless nickel plating solution whose composition has changed are the recovered liquid chamber frame 15 (H ₂ PO ₂ ⁻ ) and the waste liquid chamber frame 16 (HPO ₃ ²⁻ , SO ₄ ²⁻ ). . In other words, hypophosphite ions required in the electroless nickel plating solution are recovered in a state separated from other anions. The recovered liquid chamber frame 15 contains hypophosphite ions and hydrogen ions (H ⁺ ) generated from the cation exchange layer 14 b constituting the bipolar membrane 14. Therefore, the monovalent hypophosphite ions that have moved to the recovery liquid chamber frame 15 are converted to phosphorous acid by protons generated from the bipolar membrane 14 (or the anode chamber 21), and this phosphorous acid is recovered. It stays in the liquid chamber frame 16.

(NaOH production process)
By the way, from the characteristics of the ion exchange layers (14a, 14b) constituting the bipolar membrane 14, the water molecules that have reached the bipolar membrane 14 are separated from the hydrogen ions as shown in FIG. Converted to hydroxide ions. Specifically, hydroxide ions (OH ⁻ ) are generated from the anion exchange layer 14 a constituting the bipolar membrane 14, and hydrogen ions (H ⁺ ) are generated from the cation exchange layer 14 b constituting the bipolar membrane 14. Here, the hydroxide ions generated in the anion exchange layer 14 a move toward the anode 20 in the NaOH liquid chamber frame 18 and reach the monovalent selective cation exchange membrane 13. However, hydroxide ions are blocked by the monovalent selective cation exchange membrane 13 and stay in the NaOH liquid chamber frame 18. Accordingly, in the NaOH liquid chamber frame 18, sodium ions moved to the NaOH liquid chamber frame 18 and hydroxide ions generated in the NaOH liquid chamber frame 18 are retained. Inside, NaOH is produced in the form of an aqueous solution. The NaOH generated in the NaOH liquid chamber frame 18 is temporarily stored in the NaOH liquid tank 8. Here, as shown in FIG. 1, by providing a flow path 43 between the NaOH liquid tank 8 and the waste liquid tank 6, the NaOH stored in the NaOH liquid tank 8 is used for the pH adjustment process described above. Can do. That is, an alkali source (NaOH) necessary for adjusting the pH of the waste liquid chamber frame 16 (liquid flowing in the waste liquid chamber frame 16) to 8.5 or higher can be procured from the NaOH liquid tank 8. A flow path 44 is provided between the NaOH solution tank 8 and the plating solution tank 7. Thereby, an alkali source (NaOH) required for adjusting the pH of the electroless nickel plating solution stored in the plating solution tank 7 can be procured from the NaOH solution tank 8.

  By the way, in the chamber frame (NaOH liquid chamber frame 18) closest to the cathode chamber 3, as shown in FIG. 2B, the standard cation exchange membrane 10 is installed on the cathode 30 side. For this reason, some of the sodium ions in the chamber frame (NaOH liquid chamber frame 18) pass through the standard cation exchange membrane 10 and move to the cathode chamber 3. On the other hand, in the cathode chamber 3, hydroxide ions are generated by an electrode reaction in the cathode chamber, that is, a chemical reaction between water and electrons. For this reason, NaOH is also generated in the cathode chamber 3. Here, as shown in FIG. 1, by providing a flow path 41 between the catholyte tank 31 and the waste liquid tank 6, the NaOH stored in the catholyte tank 31 is used for the pH adjustment process described above. Can do. That is, an alkali source (NaOH) necessary for adjusting the pH of the waste liquid chamber frame 16 (liquid flowing in the waste liquid chamber frame 16) to 8.5 or higher can be procured from the catholyte tank 31. A flow path 42 is provided between the catholyte bath 31 and the plating bath 7. Thereby, an alkali source (NaOH) required for adjusting the pH of the electroless nickel plating solution stored in the plating solution tank 7 can be procured from the NaOH solution tank 8.

  On the other hand, in the chamber frame (recovered liquid chamber frame 15) closest to the anode chamber 2, as shown in FIG. 2 (c), the standard cation exchange membrane 10 is installed on the anode 20 side. In the anode chamber 2, hydrogen ions are generated by a chemical reaction between water and holes. On the other hand, since the hypophosphite ion in the chamber frame (recovered liquid chamber frame 15) is an anion, even if it approaches the standard cation exchange membrane 10, it cannot pass through the ion exchange membrane. It stays in the chamber frame (collected liquid chamber frame 15).

  As described above, the electrodialysis apparatus of the present invention has a good purity from the electroless nickel plating solution whose composition has been changed to a material necessary for the electroless nickel plating solution, that is, a solution containing hypophosphorous acid and nickel ions. Can be obtained.

  Commercially available products can be used for each of the four types of ion exchange membranes (11, 12, 13, 14) included in the intermediate chamber 4. As the standard anion exchange membrane 12, for example, Asahi Glass Engineering's Selemion AMV, Astom's Neoceptor AM1 or AM3, or the like can be used. As the monovalent selective cation exchange membrane 13, for example, Asahi Glass Engineering's Selemion CSO or Astom's Neoceptor CMS can be used. As the monovalent selective anion exchange membrane 12, for example, Asahi Glass Engineering's Selemion ASV, Astom's Neoceptor ACS or the like can be used. As the bipolar film 14, for example, Neoceptor BP-1E manufactured by Astom can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to the Example demonstrated below.

[Example 1]
The electrodialysis treatment of the electroless nickel plating solution was performed using an electrodialysis apparatus (DW-1 manufactured by Asahi Glass Engineering Co., Ltd.) having four flow paths shown in FIG.

  First, 10 L of 10 g / L potassium sulfate solution was charged into the anode tank 21, and 10 L of 5 g / L potassium sulfate solution was charged into the cathode tank 31. In addition, 40 L of an aqueous solution containing predetermined ions was added to the recovery liquid tank 5, the waste liquid tank 6, the plating liquid tank 7, and the NaOH liquid tank 8, respectively. The components of the aqueous solution charged into the recovery liquid tank 5, the waste liquid tank 6, the plating liquid tank 7 and the NaOH liquid tank 8 are shown in Table 1 below. The aqueous solution charged into the plating solution tank 7 is a deteriorated electroless nickel plating solution.

In this example (Example 1), in order to clarify what behavior the sodium ion (Na ⁺ ) contained in the electroless nickel plating solution shows during electrodialysis, other than the electroless nickel plating solution An aqueous solution containing no sodium ions was used. More specifically, an aqueous solution containing potassium ions (K ⁺ ) was used.

  Next, the chamber frame disposed in the electrodialysis apparatus (the intermediate chamber 4 thereof) is arranged from the anode 20 toward the cathode 30, the recovery liquid chamber frame 15 / the waste liquid chamber frame 16 / the plating solution chamber frame 17 / the NaOH liquid chamber frame. They were arranged so as to be 18. In this embodiment, 20 sets of combinations of four chamber frames arranged in the order of recovery liquid chamber frame 15 / waste liquid chamber frame 16 / plating liquid chamber frame 17 / NaOH liquid chamber frame 18 are prepared, and these are arranged in series. did. Next, a predetermined electrodialysis membrane (ion exchange membrane) was installed between the chamber frames. Here, the electrodialysis membrane used in this example is shown in Table 2 below together with the arrangement position.

  Next, a standard cation exchange membrane 10 (Chemion CMV, manufactured by Asahi Glass Engineering Co., Ltd.) was installed between the chamber frame used as the anode chamber 2 and the recovery chamber frame 15 adjacent to the chamber frame. A standard cation exchange membrane 10 (Chemion CMV, manufactured by Asahi Glass Engineering Co., Ltd.) was also installed between the chamber frame used as the cathode chamber 3 and the NaOH liquid chamber frame 18 adjacent to the chamber frame.

The chamber frame and the electrodialysis membrane used in this example are both members used for the DW-1 type. In the electrodialysis membrane used, the effective area of the electrodialysis membrane is 5 dm ² .

  Next, as shown in FIG. 1, each chamber frame (2, 3, 15, 16, 17, 18) corresponds to the corresponding liquid tank (21, 31, 5, 6, 7, 8). Connected using the circulation system (22, 32, 45, 46, 47, 48). In each circulation system (22, 32, 45, 46, 47, 48), a pump for circulating the aqueous solution put in the corresponding liquid tank (21, 31, 5, 6, 7, 8). (Not shown) are provided.

Also, four types of flow paths shown in the following (i) to (iv) were installed. The flow path 41 and the flow path 43 are used for pH adjustment of the waste liquid tank 6 during dialysis, and the flow path 42 and the flow path 44 are for pH adjustment of the electroless nickel plating solution after dialysis is completed. used.
(I) A flow path 41 provided between the waste liquid tank 6 and the cathode tank 31 for transporting the solution stored in the cathode tank 31 to the waste liquid tank 6.
(Ii) A flow path 42 provided between the plating solution tank 7 and the cathode tank 31 for transporting the solution stored in the cathode tank 31 to the plating solution tank 7.
(Iii) A channel 43 provided between the NaOH solution tank 8 and the waste solution tank 6 for transporting the solution stored in the NaOH solution tank 8 to the waste solution tank 6.
(Iv) A flow path 44 provided between the plating solution tank 7 and the NaOH solution tank 8 for transporting the solution stored in the NaOH solution tank 8 to the plating solution tank 7.

Next, a constant current (2 A / dm ² direct current, total current 20 A) was passed between the anode 20 and the cathode 30 for 5 hours. In the waste liquid tank 6, the pH of the aqueous solution was adjusted to 8.5 in order to convert monovalent phosphorous acid (H ₂ PO ₃ ⁻ ) into divalent phosphorous acid (HPO ₃ ²⁻ ). In this example, in order to evaluate the behavior of sodium ions (Na ⁺ ) during dialysis, pH adjustment of the waste liquid tank 6 was performed by appropriately adding KOH adjusted separately from the outside. Here, in the KOH added from the outside, the concentration of potassium ion (K ⁺ ) was 2.0 g / L, and the concentration of hydroxide ion (OH ⁻ ) was 0.8 g / L.

  After the electrodialysis is completed, a capillary electrophoresis measurement device (manufactured by Agilent Technologies) and a salinity (Na) concentration meter (manufactured by HORIBA) are used for the aqueous solution stored in each liquid tank (5, 6, 7, 8). ) Was used to measure and evaluate the ion concentration in the aqueous solution. The results are shown in Table 3 below.

  Moreover, it evaluated about the component of the mixed solution (final electroless nickel plating liquid) which mixed the electroless nickel plating liquid after an electrodialysis process, and the liquid stored in the collection tank 5 after an electrodialysis process. Specifically, the evaluation was performed using the concentration ratio when each component of the electroless nickel plating solution before the electrodialysis treatment was used as a reference (100%). The evaluation results are shown in Table 4 below.

By the way, as shown in Table 3, sodium ions and potassium ions were not detected from the solution stored in the recovery liquid tank 15. From this, the hypophosphite ions (H ₂ PO ₂ ⁻ ) moved to the recovery liquid tank 15 are combined with the hydrogen ions (H ⁺ ) generated from the bipolar membrane 14 (the cation generation layer 14b thereof), and hypo hypoxia. It is thought that it exists as phosphoric acid (H ₃ PO ₂ ). Therefore, it can be seen that there is no problem even if the aqueous solution stored in the recovery liquid tank 15 is merged with the electroless nickel plating liquid stored in the plating liquid tank 7 after the electrodialysis is completed. In this example, the increase in the concentration of hydroxide ions in the NaOH liquid tank due to generation from each bipolar membrane 14 (anion generation layer 14a thereof) and collection in the NaOH liquid tank was 1.52 g / L. . This can be said that the hydroxide ion increased by 60.8 g due to the chemical reaction (H ₂ O → H ⁺ + OH ⁻ ) in each bipolar membrane 14 (anion generation layer 14a thereof).

As described above, by using the electrodialysis apparatus of this example, nickel ions (Ni ²⁺ ) and hypophosphite ions (H ₂ PO ₂ ⁻ ), which are active components of the electroless nickel plating solution, can be recovered with high efficiency. It was. In addition, phosphite ions (H ₂ PO ₃ ⁻ ), sulfate ions (SO ₄ ²⁻ ) and sodium ions (Na ⁺ ), which are impurities for the electroless nickel plating solution, could be removed with high efficiency.

[Comparative Example 1]
The electrodialysis treatment of the electroless nickel plating solution was performed using two electrodialysis apparatuses (DW-1 manufactured by Asahi Glass Engineering Co., Ltd.) having two flow paths shown in FIG.

  First, 10 L of 10 g / L potassium sulfate solution was charged into the anode tank 121, and 10 L of 5 g / L potassium sulfate solution was charged into the cathode tank 131. In addition, 40 L of an aqueous solution containing predetermined ions was added to the recovery liquid tank 105, the first waste liquid tank 106, the plating liquid tank 107, and the second waste liquid tank 108, respectively. The components of the aqueous solution charged into the recovery liquid tank 105, the first waste liquid tank 106, the plating liquid tank 107, and the second waste liquid tank 108 are shown in Table 5 below. The aqueous solution charged into the plating solution tank 107 is a deteriorated electroless nickel plating solution.

In this comparative example (Comparative Example 1), for the same purpose as in Example 1, an aqueous solution containing potassium ions (K ⁺ ) was used as an aqueous solution other than the electroless nickel plating solution.

  Next, the chamber frame disposed in the first electrodialysis apparatus (the intermediate chamber 104a thereof) was disposed so as to be the plating solution chamber frame 117 / first waste liquid chamber frame 116 from the anode 120a toward the cathode 130a. In this comparative example, 10 sets of combinations of two chamber frames arranged in the order of plating solution chamber frame 117 / first waste liquid chamber frame 116 were prepared, and these were arranged in series.

  Further, the chamber frame disposed in the second electrodialysis apparatus (the intermediate chamber 104b thereof) was arranged from the anode 120 toward the cathode 130 so as to be the second waste liquid chamber frame 118 / recovered liquid chamber frame 115. In this comparative example, 10 combinations of two chamber frames arranged in the order of the second waste liquid chamber frame 118 / recovered liquid chamber frame 115 were prepared, and these were arranged in series.

  Next, a predetermined electrodialysis membrane (ion exchange membrane) was installed between the chamber frames. Here, the electrodialysis membrane used in this comparative example is shown in Table 6 below together with the arrangement position.

  Next, a standard cation exchange membrane 110 (manufactured by Asahi Glass Engineering Co., Ltd., Selemion CMV) was installed between the chamber frame used as the anode chamber (102a, 102b) and the chamber frame adjacent to the chamber frame. Further, a standard cation exchange membrane 110 (manufactured by Asahi Glass Engineering Co., Ltd., Selemion CMV) was also installed between the chamber frame used as the cathode chamber (103a, 103b) and the chamber frame adjacent to the chamber frame.

The chamber frame and the electrodialysis membrane used in this comparative example are both members used for the DW-1 type. In the electrodialysis membrane used, the effective area of the electrodialysis membrane is 5 dm ² .

  Next, each chamber frame (102, 103, 115, 116, 117, 118) and the corresponding liquid tank (121, 131, 105, 106, 107, 108) are respectively connected to the corresponding circulation system (122, 132, 145, 146, 147, 148). FIG. 4 shows all or part of the circulatory system. In addition, in each circulation system (122, 132, 145, 146, 147, 148), a pump for circulating the aqueous solution put into the corresponding liquid tank (121, 131, 105, 106, 107, 108) (Not shown) are provided. Between the first waste liquid tank 106 and the second waste liquid tank 108, a flow path 141 for introducing the aqueous solution stored in the first waste liquid tank 106 into the second waste liquid tank 108 is provided.

Next, a constant current (2 A / dm ² direct current, total current 20 A) was passed between the anode 120 and the cathode 130 for 5 hours. In the second waste liquid tank 106, an aqueous solution is used in the same manner as in Example 1 in order to convert monovalent phosphorous acid (H ₂ PO ₃ ⁻ ) into divalent phosphorous acid (HPO ₃ ²⁻ ). The pH of was adjusted to 8.5.

  After completion of electrodialysis, the ion concentration in the aqueous solution was measured and evaluated by the same method as in Example 1 for the aqueous solution stored in each liquid tank (105, 106, 107, 108). The results are shown in Table 7 below.

  Further, the components of the final electroless nickel plating solution were evaluated by the same method as in Example 1. The evaluation results are shown in Table 8 below.

  From Table 8, the electrodialysis apparatus of this comparative example was substantially the same as in Example 1 in the recovery efficiency of nickel ions and hypophosphite ions, and the removal efficiency of phosphite ions and sulfate ions, but sodium ions It was inferior to Example 1 in the viewpoint of the removal efficiency. Thus, the reason why the removal efficiency of sodium ions was poor is that the ion selectivity in the hydrogen selective cation exchange membrane 113 was not sufficient.

[Example 2]
In Example 1, 10 g / L of sodium sulfate solution 10 L was added to the anode tank 21, and 10 g of 5 g / L NaOH solution was added to the cathode tank 31. Except for these, electrodialysis was performed in the same manner as in Example 1. Table 9 below shows the components of the aqueous solution charged into the recovery liquid tank 5, the waste liquid tank 6, the plating liquid tank 7, and the NaOH liquid tank 8 in this example (Example 2).

  Moreover, the components of the aqueous solution thrown into the cathode chamber 31 were 2.9 g / L of sodium ions and 2.1 g / L of hydroxide ions.

  Next, after electrodialysis, the components of the solutions contained in the respective liquid tanks were analyzed by the same method as in Example 1. The analysis results are shown in Table 10.

  In the cathode chamber 31, the hydroxide ion increased by 3.0 g / L. That is, as a result of electrodialysis, it can be seen that 3.0 g / L of hydroxide ions was generated and introduced into the cathode chamber 31.

Here, by measuring the concentration of hydroxide ions (OH ⁻ ) in the aqueous solution stored in the NaOH solution tank 8 and the cathode chamber 31 before and after electrodialysis, the hydroxide ions generated by electrodialysis are quantitatively determined. Evaluated. The evaluation results are shown in Table 11 below.

  In addition, the amount of hydroxide ions required to adjust the pH of the waste liquid stored in the waste liquid tank 6 and the pH of the electroless nickel plating liquid stored in the plating liquid tank 7 were required. The amount of hydroxide ions was evaluated. The results are shown in Table 12 below.

  From Table 11, 28.0 g of hydroxide ions were generated in the NaOH liquid tank 8 by performing electrodialysis. Further, from Table 11, in the waste liquid tank 6, the hydroxide ion concentration increased by 32.0 g. For this reason, a total of 60.8 g of hydroxide ions was generated by the ion exchange reaction in the bipolar membrane 14. On the other hand, from Table 11, 30.0 g of hydroxide ions were generated in the cathode chamber 31 by performing electrodialysis. Therefore, the hydroxide ion produced | generated in the present Example was 90.8g.

  Moreover, from Table 12, the hydroxide ion required for pH adjustment (adjustment from pH 7.5 to pH 8.5) in the waste liquid tank 6 is 36.0 g, and pH adjustment in the plating liquid tank 7 (pH 4. The amount of hydroxide ion required for the adjustment from 2 to pH 5.6 was 105.0 g. For this reason, it turns out that the sum total of the hydroxide ion required for pH adjustment in each of the waste liquid tank 6 and the plating liquid tank 7 is 141.8g.

  From the above, the amount of hydroxide ions obtained by the electrodialysis treatment in this example was sufficiently larger than the amount of hydroxide ions required for pH adjustment in the waste liquid tank 6. Specifically, hydroxide ions required for pH adjustment in the waste liquid tank 6 (hydroxide ions necessary for converting monovalent phosphite ions to divalent phosphite ions) It can be covered with hydroxide ions obtained by electrodialysis treatment. Further, about 52% of the hydroxide ions required for pH adjustment in the plating layer 6 were not used in the pH adjustment in the waste liquid tank 6 among the hydroxide ions obtained by electrodialysis. Can be covered by object ions.

  The present invention is not limited to the above-described embodiments, and an intermediate chamber defined by an anion exchange membrane and a cation exchange membrane is provided between the anode and the cathode, and the intermediate chamber is partitioned by a bipolar membrane. The electrodialysis apparatus for electroless plating solution having That is, the present invention substantially restricts the movement of a predetermined ion component in the intermediate chamber by partitioning the intermediate chamber with the bipolar membrane, and the space in the partitioned intermediate chamber (the gap between the anion exchange membrane and the bipolar membrane, or The removal efficiency and recovery efficiency of a predetermined ion component from the gap between the cation exchange membrane and the bipolar membrane) can be remarkably improved. In addition, since the present invention can remove and recover a predetermined ion component by the bipolar film, for example, the predetermined ion component is taken out from the used plating solution, and the extracted predetermined ion component is reused as a component of the plating solution. The present invention can also be applied as a plating solution regeneration device and a plating solution regeneration system for use. Specifically, the regenerating apparatus (electrodialysis apparatus) of the present invention is connected to a plating apparatus such as an electroless plating apparatus, and a predetermined ion component recovered from the regenerating apparatus of the present invention is again supplied to the plating apparatus. The present invention can be applied as a plating solution recycling system or a plating solution recycling system that is returned (reused) as a component of the plating solution.

  1: electrodialyzer, 2: anode chamber, 3: cathode chamber, 4: intermediate chamber, 5: recovery bath, 6: waste bath, 7: electroless nickel plating bath, 8: NaOH bath, 9: pH Control device, 10: standard cation exchange membrane, 11: 1 valent selective anion exchange membrane, 12: standard anion exchange membrane, 13: 1 valent selective cation exchange membrane, 14: bipolar membrane, 14a: anion exchange layer, 14b: cation exchange 15: recovery liquid chamber frame, 16: waste liquid chamber frame, 17: plating liquid chamber frame, 18: NaOH liquid chamber frame, 20: anode, 21: anode tank, 22: anolyte circulation system, 30: cathode, 31 : Cathode tank, 32: Catholyte circulation system, 41 (42, 43, 44): Channel, 45: Recovery liquid circulation system, 46: Waste liquid circulation system, 47: Electroless nickel plating solution circulation system, 48: NaOH solution Circulation system

Claims (15)

An anode chamber in which the anode is disposed;
A cathode chamber in which the cathode is disposed;
An intermediate chamber provided between the anode chamber and the cathode chamber,
In the electrodialysis apparatus in which an ion exchange membrane is disposed between the anode chamber and the intermediate chamber and between the cathode chamber and the intermediate chamber, respectively.
The intermediate chamber includes a monovalent selective anion exchange membrane, a standard anion exchange membrane, a monovalent selective cation exchange membrane, a bipolar membrane, the monovalent selective anion exchange membrane, the standard anion exchange membrane, the 1 Having a plurality of configurations consisting of a valence-selective cation exchange membrane or four types of chamber frames for distributing a predetermined solution to the bipolar membrane,
The monovalent selective anion exchange membrane, the standard anion exchange membrane, the monovalent selective cation exchange membrane, and the bipolar membrane are formed from the anode chamber toward the cathode chamber, the monovalent selective anion exchange membrane, A standard anion exchange membrane, the monovalent selective cation exchange membrane and the bipolar membrane are arranged in this order,
The electrodialysis apparatus, wherein the configuration has four flow paths. The bipolar membrane is an anion exchange layer provided on the anode side;
The electrodialyzer according to claim 1, comprising a cation exchange layer provided on the cathode side. The four types of chamber frames are a collection liquid chamber frame, a waste liquid chamber frame, a plating solution chamber frame or an NaOH liquid chamber frame, respectively.
In the above configuration, from the anode chamber toward the cathode chamber, the recovery liquid chamber frame, the monovalent selective anion exchange membrane, the waste liquid chamber frame, the standard anion exchange membrane, the plating solution chamber frame, the monovalent The electrodialysis apparatus according to claim 1 or 2, wherein the selective cation exchange membrane, the NaOH liquid chamber frame, and the bipolar membrane are arranged in this order.   The electrodialysis apparatus according to claim 3, wherein an electroless nickel plating solution is introduced into the plating solution chamber frame. In the NaOH liquid chamber frame, the NaOH liquid chamber passes through the monovalent selective cation exchange membrane contained in the electroless nickel plating solution and hydroxide ions generated by the anion exchange layer of the bipolar membrane. Sodium ions that have moved to the frame are retained in the NaOH liquid chamber frame to generate NaOH,
The electrodialysis apparatus according to claim 3 or 4, further comprising a flow path for adding NaOH generated in the NaOH liquid chamber frame to the liquid circulating in the waste liquid chamber frame.   Using the flow path, the pH of the liquid circulating in the waste liquid chamber frame is set to 8.5 or more by adding NaOH generated in the NaOH liquid chamber frame to the liquid circulating in the waste liquid chamber frame. The electrodialysis apparatus according to any one of claims 3 to 5, wherein the electrodialysis apparatus is characterized. A cation exchange membrane is installed between the cathode chamber and the NaOH liquid chamber frame closest to the cathode chamber,
Sodium ions present in the NaOH liquid chamber frame closest to the cathode chamber are transferred to the cathode chamber through the cation exchange membrane,
NaOH is generated in the cathode chamber by hydroxide ions generated in the cathode chamber by the electrode reaction in the cathode chamber and sodium ions moved to the cathode chamber,
The cathode chamber has a flow path for adding NaOH generated in the cathode chamber to the liquid circulating in the waste liquid chamber frame so that the pH of the liquid circulating in the waste liquid chamber frame is 8.5 or more. The electrodialysis apparatus according to claim 3, wherein the electrodialysis apparatus is provided.   An electrodialysis apparatus for an electroless plating solution, wherein an intermediate chamber provided between an anode and a cathode and defined by an anion exchange membrane and a cation exchange membrane is partitioned by a bipolar membrane. In the electrodialysis method performed using the electrodialysis apparatus according to any one of claims 1 to 8,
A voltage application process in which an electroless nickel plating solution is introduced into a plating solution chamber frame disposed between a standard anion exchange membrane and a monovalent selective cation exchange membrane and a voltage is applied;
When the voltage application process is performed, the divalent sulfate ion, the monovalent phosphite ion, and the hypophosphite ion contained in the electroless nickel plating solution are transmitted through the standard anion exchange membrane. Move it to the waste liquid chamber frame,
Divalent nickel ions contained in the electroless nickel plating solution are retained in the plating solution chamber frame;
An electrodialysis method, wherein monovalent sodium ions contained in the electroless nickel plating solution are permeated through a monovalent selective cation exchange membrane and then moved to a NaOH solution chamber frame. A pH adjustment process for introducing a hydroxide ion into a waste liquid chamber frame disposed between the monovalent selective anion exchange membrane and the standard anion exchange membrane so that the pH in the waste liquid chamber frame is 8.5 or more. In addition,
Of the anions transferred to the waste liquid chamber frame, monovalent phosphite ions are converted into divalent phosphite ions,
The sulfuric acid ions and divalent phosphite ions contained in the waste liquid chamber frame are retained in the waste liquid chamber frame, and the monovalent phosphite ions are allowed to permeate through the monovalent selective anion exchange membrane before the recovery liquid chamber frame. The electrodialysis method according to claim 9, wherein The monovalent hypophosphite ions that have moved to the recovered liquid chamber frame are converted into phosphorous acid by hydrogen ions generated from the anode chamber or the bipolar membrane,
The electrodialysis method according to claim 10, wherein the phosphorous acid stays in the recovered liquid chamber frame. A NaOH generation process for generating NaOH in a NaOH liquid chamber frame disposed between the bipolar membrane and the monovalent selective cation exchange membrane;
The NaOH generation process is moved to the NaOH liquid chamber frame and stays in the NaOH liquid chamber frame by the bipolar membrane;
The electrodialysis method according to claim 10 or 11, wherein the electrodialysis method is a process of generating NaOH by combining hydroxide ions generated from an anion exchange layer of the bipolar membrane.   The electrodialysis method according to any one of claims 10 to 12, wherein NaOH produced in the NaOH production process is used in the pH adjustment process. A cation exchange membrane is installed between the cathode chamber and the NaOH liquid chamber frame closest to the cathode chamber,
Sodium ions present in the NaOH liquid chamber frame closest to the cathode chamber are permeated through the cation exchange membrane and then moved to the cathode chamber,
NaOH is generated in the cathode chamber by the hydroxide ions generated in the cathode chamber by the electrode reaction in the cathode chamber, and the sodium ions,
14. The electrodialysis method according to claim 10, wherein NaOH generated in the cathode chamber is used for the pH adjustment process.   A plating system comprising: the electrodialysis apparatus according to any one of claims 1 to 8; and a plating apparatus.

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