JP4991655B2 - Electrodialysis machine - Google Patents

Description

  The present invention relates to an electrodialysis apparatus that removes ions to be removed from an electrolyte solution containing ions to be removed by electrodialysis.

  In an electrolyte solution containing an anion and a cation, for example, an electroless Ni or Cu plating solution, a plurality of anions and cation species that inhibit the reaction are accumulated by use. As anions, there are a plurality of anions such as phosphorous acid and formic acid decomposed by a reducing agent such as hypophosphorous acid and formalin, and sulfuric acid and chlorine as counter ions of the deficient metal ions. As cations, there are Na and K as counter ions of supplemental metal components such as Ni and Cu, and a plurality of cations such as iron and lead as metal impurities.

  An electrodialysis method has been proposed to remove the accumulated ions. In the electrodialysis method, effective ions are removed at the same time as removal of ions excluded from the object, so it is important to reduce the removal of effective ions. The ion removal amount has an individual value depending on the ion exchange membrane used for each ion, and when multiple types of ions to be removed exist, dialysis is simultaneously performed against the removal target amount of each ion to be removed. Termination is necessary to reduce the loss of active ingredients.

  For example, Patent Document 1 proposes that a cation film is disposed on the cathode side of the electrolyte solution to remove cations, and an anion film is disposed on the anode side to remove anions. However, when removing multiple species of the same ionic species at the same time, there is a difference in the removal efficiency between each ion and the ion exchange membrane to be used, and at the end of removal, either ion is excessively or insufficiently dialyzed. It will end. Further, if all the ions to be removed are removed as intended, the dialysis time becomes longer, the amount of active ingredient removed increases, and dialysis efficiency is hindered.

Further, in Patent Document 2, phosphorous acid, which is an ion to be removed, is concentrated by first stage dialysis, and then the pH of the solution is changed from 6 to 10 to convert the phosphorous acid to a divalent ion, which is an anion having monovalent selectivity. By using an ion exchange membrane, the active ingredient hypophosphite ions are effectively separated.
Further, Patent Document 3 proposes to separate phosphorous acid and hypophosphorous acid by performing two-stage dialysis and using a monovalent selective anion exchange membrane in the second stage.

However, basically, when removing a plurality of ions of at least one of anions and cations, the dialysis is excessive or insufficient as in Patent Document 1. Further, if all the ions to be removed are to be removed according to the target, the removal amount of the active ingredient is increased and the dialysis efficiency is hindered.
Japanese Laid-Open Patent Publication No. 63-303078 JP 2004-52029 A Japanese Patent No. 3420570

As described above, in the prior art, no proposal has been made to efficiently and efficiently remove an electrolyte solution having a plurality of ions to be removed with the same ionic species.
The present invention has been made in view of such a background art, and is to be simultaneously removed from an electrolyte solution containing at least one of anion or cation species, which are ions to be removed, using an electrodialysis method. It is an object of the present invention to provide an electrodialysis apparatus that removes ions and reduces the loss of active ion components during dialysis.

Thus, the present invention
An electrodialysis apparatus that removes the plurality of types of removal target ions in preference to the effective ions by an electrodialysis method from an electrolyte solution containing effective ions and a plurality of types of removal target ions ,
Comprising a plurality of cation exchange membranes and a plurality of anion exchange membranes are dialysis membrane between the anode and the cathode,
At least one of the cation exchange membrane or the anion exchange membrane is configured by overlapping a plurality of sub ion exchange membranes each having a different area,
Wherein the plurality of sub-ion exchange membranes, specific ion movement amount represented by the following formula (1) of the removal target ions have Tsu different respectively,
The specific ion transfer amount of the ions to be removed that the secondary ion exchange membrane has is larger than the specific ion transfer amount of the effective ions that the secondary ion exchange membrane has,
The area ratio of each of the secondary ion exchange membranes is represented by the following formula (2) .

However, specific ion transfer amount (g / (A × H) / dm ² ) = ion transfer amount (g) ÷ electric amount (A × H) ÷ ion exchange membrane area (dm ² ) (1)
(In the formula, the area of the ion exchange membrane indicates the area of one sub ion exchange membrane .)
Formula (2) is shown as follows.
AMI1 = (SA1 × ZA × A1I1 +... + SAN × ZA × ANI1) × Q
AMI2 = (SA1 × ZA × A1I2 +... + SAN × ZA × ANI2) × Q
・
・
AMIn = (SA1 × ZA × A1In +... + SAN × ZA × ANIn) × Q
(Where SA1... SAN is the area ratio of the sub-ion exchange membrane, AMI1... AMIn is the removal target amount (g) of ion n species (I1... In) to be removed, and A1I1. A1In to ANI1... ANIn is a specific ion transfer amount (g / (A × H) for n types of ions to be removed (I1... In) for each of the secondary ion exchange membrane N types (A1... AN) used. ) / Dm ² ), Q is the quantity of electricity during dialysis (A × H), and ZA is the total area (dm ² ) of either the cation exchange membrane or the anion exchange membrane used. .)

  According to the present invention, by using an electrodialysis method, ions to be removed are simultaneously removed from an electrolyte solution containing a plurality of anion or cation species that are ions to be removed, and active ion components are dialyzed. It is possible to provide an electrodialysis apparatus with a small loss.

Hereinafter, the present invention will be described in detail.
The electrodialysis apparatus according to the present invention removes the plurality of types of removal target ions with priority over the effective ions from an electrolyte solution containing effective ions and a plurality of types of removal target ions by an electrodialysis method. Because
Comprising a plurality of cation exchange membranes and a plurality of anion exchange membranes are dialysis membrane between the anode and the cathode,
At least one of the cation exchange membrane or the anion exchange membrane is configured by overlapping a plurality of sub ion exchange membranes each having a different area,
Wherein the plurality of sub-ion exchange membranes, specific ion movement amount represented by the following formula (1) of the removal target ions have Tsu different respectively,
The specific ion transfer amount of the ions to be removed that the secondary ion exchange membrane has is larger than the specific ion transfer amount of the effective ions that the secondary ion exchange membrane has,
The area ratio of each of the secondary ion exchange membranes is represented by the following formula (2) .

However, specific ion transfer amount (g / (A × H) / dm ² ) = ion transfer amount (g) ÷ electric amount (A × H) ÷ ion exchange membrane area (dm ² ) (1)
(In the formula, the area of the ion exchange membrane indicates the area of one sub ion exchange membrane .)
Formula (2) is shown as follows.
AMI1 = (SA1 × ZA × A1I1 +... + SAN × ZA × ANI1) × Q
AMI2 = (SA1 × ZA × A1I2 +... + SAN × ZA × ANI2) × Q
・
・
AMIn = (SA1 × ZA × A1In +... + SAN × ZA × ANIn) × Q
(Where SA1... SAN is the area ratio of the sub-ion exchange membrane, AMI1... AMIn is the removal target amount (g) of ion n species (I1... In) to be removed, and A1I1. A1In to ANI1... ANIn is a specific ion transfer amount (g / (A × H) for n types of ions to be removed (I1... In) for each of the secondary ion exchange membrane N types (A1... AN) used. ) / Dm ² ), Q is the quantity of electricity during dialysis (A × H), and ZA is the total area (dm ² ) of either the cation exchange membrane or the anion exchange membrane used. .)

  In the basic configuration of the electrodialysis apparatus of the present invention, an anion exchange membrane is arranged as a membrane in contact with the anode side of the electrolyte solution for desalting, and a cation exchange membrane is arranged on the cathode side. In the electrolyte solution to be desalted, there are a plurality of ions in the cation or a plurality of ions in the anion as ions to be removed. Examples of the electrolyte solution in which a plurality of ions to be removed exist in the solution include electroless plating solutions such as Ni, copper, and gold.

  The anion component to be removed is phosphorous acid or formic acid, which is a decomposition product of the reducing agent, and an anion such as sulfuric acid or chlorine as a counter ion of the supplement component, and a plurality of types of ions accumulate with use. In addition, the cation component to be removed accumulates a plurality of types such as Na and k as counter ions such as various organic acids and reducing agents, and metal ions such as iron, copper and lead as impurity ions. For this reason, an electrodialysis apparatus in which a plurality of ion exchange membranes suitable for each ion are arranged in one dialysis apparatus is used.

The present invention is characterized in that an ion exchange membrane having a plurality of intrinsic ion migration amounts (g / (A × H) / dm ² ) obtained below is incorporated in one electrodialysis apparatus.
The specific ion transfer amount is a specific value of each ion exchange membrane with respect to the target ion, and can be obtained by the following formula (1).
Inherent ion transfer amount (g / (A × H) / dm ² ) = ion transfer amount (g) ÷ electric amount (A × H) ÷ ion exchange membrane area (dm ² ) (1)

  In formula (1), the amount of ion movement is given by the amount (g) of the target ion moved by dialysis treatment, the amount of electricity is given by the product of current and time to the ion exchange membrane, and the ion exchange membrane area is dialysis It is given by the total area of the anion or cation exchange membrane placed between the anode and cathode of the device.

In the present invention, at least one of the cation exchange membrane and the anion exchange membrane comprises a plurality of membranes, and the plurality of membranes are determined from the intrinsic ion migration amount (g / (A × H) / dm ² ). It is preferable that the area ratios of the films differ.

  Further, in the present invention, when the ion to be removed is an anion, the anion is n species (I1... In), and the anion exchange membrane to be used is N species (A1... AN), The area ratio (SA1... SAN) of the N kinds of anion exchange membranes is preferably obtained from the following formula.

AMI1 = (SA1 × ZA × A1I1 +... + SAN × ZA × ANI1) × Q
AMI2 = (SA1 × ZA × A1I2 +... + SAN × ZA × ANI2) × Q
・
・
AMIn = (SA1 × ZA × A1In +... + SAN × ZA × ANIn) × Q
(In the formula, AMI1 ·· AMIn is the removal target amount (g) of anion n species (I1... In) to be removed, and A1I1 ·· A1In to ANI1 ·· ANIn are the anion exchange membrane N species (A1 · · · AN (specific ion movement amount at I1 ··· in) (g / ( a × H) removing the target anion n species each) / ^dm 2), Q is the quantity of electricity during dialysis (a × H ), ZA represents the total area (dm ² ) of the anion exchange membrane used.)

  Further, in the present invention, when the ion to be removed is a cation, the cation is n species (I1... In), and the cation exchange membrane to be used is N species (K1... KN), It is preferable that the area ratio (SK1... SKN) of the N kinds of cation exchange membranes is obtained from the following formula.

KMI1 = (SK1 × ZK × K1I1 +... + SKN × ZK × KNI1) × Q
KMI2 = (SK1 × ZK × K1I2 ++... + SKN × ZK × KNI2) × Q
・
・
KMIn = (SK1 × ZK × K1In +... + SKN × ZK × KnIn) × Q
(Where KMI1 ·· KMIn is the removal target amount (g) of cation n species (I1... In) to be removed, and K1I1 ·· K1In to KNI1 ·· KNIn are cation exchange membrane N species (K1) · · · KN (specific ion movement amount at I1 ··· in) (g / ( a × H) removing the target cation n species each) / ^dm 2), Q is the quantity of electricity during dialysis (a × H ), ZK represents the total area (dm ² ) of the cation exchange membrane used.)

  The anion exchange membrane of the ion exchange membrane used in the present invention is a membrane excellent in the removal of phosphorous acid, formic acid and the like, which are decomposition products of the reducing agent, such as Astom Neocepta ACS, Asahi Glass Engineering Selemion ASV, etc. . As membranes excellent in removability of sulfuric acid / chlorine or the like as counter ions of the supplement component, Astom Neoceptors AM1 and AM3 and Asahi Glass Engineering Selemion AMV membranes are used according to the removal target amount.

  As the cation exchange membrane used in the present invention, a Selemion CMV membrane, an Astom Neoceptor CM1 or CM2 or the like is used when Na / k or the like is preferentially removed as a counter ion. When it is desired to preferentially remove metal impurity ions such as iron, copper and lead, Astom Neoceptor CMS, Asahi Glass Engineering Selemion CSO, DuPont Nafion 424 and the like are used.

The area ratio of the ion exchange membrane is determined according to the removal target amount of the anion exchange membrane and the cation exchange membrane.
The electrolysis conditions used in the present invention are not particularly limited, but usually 0.1 A / dm ² to 10 A / dm ² is usually used.

  As described above, when multiple types of ion species to be removed are mixed in each positive / anion ion, each target amount of multiple ions to be removed can be changed by changing the area ratio of the ion exchange membrane constituting the electrodialysis apparatus. At the same time, the loss of active ingredients during dialysis is reduced and dialysis efficiency is improved.

  In the electrodialysis for the purpose of removing multiple ions, the present invention is configured such that an anion exchange membrane or a cation exchange membrane is composed of an ion exchange membrane having a plurality of kinds of intrinsic ion migration amounts to simultaneously reach a target concentration. Use the arranged electrodialyzer.

Hereinafter, the electrodialysis apparatus of the present invention will be described in detail using electroless Ni as an example with reference to the drawings.
FIG. 1 is a conceptual diagram showing an embodiment of the electrodialysis apparatus of the present invention. In FIG. 1, a plating solution 1 to be electrodialyzed is circulated and regenerated in a plating tank 2 via an electrodialyzer 3 by a circulation pump 6. The concentrated solution 4 dialyzed by the electrodialysis apparatus 3 is circulated and regenerated to the concentration tank 5 via the electrodialysis apparatus 3 by the circulation pump 7. At the time of dialysis, a predetermined current is supplied by a DC power source of the power source 8.

FIG. 2 is a conceptual diagram showing another embodiment of the electrodialysis apparatus of the present invention. 1 shows an electrodialysis apparatus 3 in which an anion exchange membrane and a cation exchange membrane are each composed of N types of ion exchange membranes. A plating solution is introduced into the plating chamber 9, and an electrolyte such as sodium sulfate or sulfuric acid that does not affect the plating solution is introduced into the concentration chamber 10. The block 1 is composed of an ion exchange membrane (anion membrane A1, cation membrane K1) for giving priority to the first negative or positive ion to be removed (for example, sulfuric acid for anion and Na for positive ion). The block N is composed of an ion exchange membrane (anion membrane An, cation membrane Kn) for giving priority to the Nth anion or cation to be removed (for example, phosphorous acid for anions, iron for cations). . The number of blocks allocated is determined by the time required for dialysis and the like based on the specific ion movement amount (g / (A × H) / dm ² ) of each ion. In FIG. 2, N types of ion exchange membranes are arranged for each block, but the order of the membranes is not limited as long as the membrane area ratio is maintained.

In the present invention, the specific ion migration amount (g / (A × H) / dm ² ) of ions is measured by the apparatus shown in FIGS.
FIG. 3 is a conceptual diagram showing an apparatus for determining the intrinsic ion migration amount of the cation exchange membrane. From FIG. 3, the intrinsic ion migration amount of the cation exchange membrane can be obtained. A predetermined amount of desalted liquid adjusted to a predetermined concentration is placed on the anode chamber side, a cation exchange membrane 21 to be evaluated is installed, an electrolyte such as sulfuric acid or sodium sulfate is placed on the cathode side, and a certain amount of electricity is applied to move ions. The amount can be measured and converted per unit.

  FIG. 4 is a conceptual diagram showing an apparatus for obtaining the intrinsic ion migration amount of the anion exchange membrane. With reference to FIG. 4, the intrinsic ion migration amount of the anion exchange membrane can be obtained. A predetermined amount of desalted liquid adjusted to a predetermined concentration is placed on the cathode chamber side, an anion exchange membrane 31 to be evaluated is installed, and an electrolyte such as sulfuric acid or sodium sulfate is placed on the anode side, giving a certain amount of electricity and ion migration The amount can be measured and converted per unit.

Hereinafter, the present invention will be specifically described with reference to examples.
Example 1
Using the apparatus of FIG. 4, electroless Ni solution (Ni ²⁺ : 5 g / L, sulfuric acid (A): 40 g / L, phosphorous acid (B) ²⁻ : 60 g / L, hypophosphorous acid ⁻ : 35 g / L, sodium : 60 g / L) 1 L was placed in a desalting chamber, and 1 L of a 10 g / L sodium acetate solution was placed in the concentration chamber. An anion exchange membrane AMV membrane (SI) or ACS membrane (SII) having a membrane area of 1 dm ² is formed as an anion membrane for evaluation, and sulfuric acid ^2- (A), phosphate ^2-(B), hypophosphite ^- the amount of movement of the ions each ion corresponding to each film was measured using capillary electrophoresis apparatus (manufactured by Yokogawa Ana Ryi Pharmaceuticals, Inc.) in (C) (g) Obtained. The results are shown in Table 1.

Subsequently, the specific ion transfer amount (g / (A × H) / dm ² ) of each ion of each film was obtained. The results are shown in Table 2.

Then, in order to remove phosphorous acid and sulfate ions, which are components that do not require anions, as an electroless Ni plating solution, using the electrodialysis apparatus shown in FIG. Dialysis with an anion exchange membrane area of 35 dm ² to achieve a sulfuric acid concentration (A) of 5 g / L (removal target amount is 3500 g) and phosphorous acid concentration (B) is 10 g / L (removal target amount is 5000 g). The unit was prepared, and the membrane area ratio (AMV / ACS) = (SI / SII) of the anion exchange membrane when the amount of electricity was Q was determined below.

(Sulfate ion)
3500 = (35 × SI × 2.2 + 35 × SII × 1.3) × Q
(Phosphite ion)
5000 = (35 × SI × 0.9 + 35 × SII × 2.6) × Q
AMV / ACS = SI / SII = 16.3Q / 49.3Q
As described above, each membrane area ratio in the membrane area of 35 dm ² of the anion exchange membrane is obtained as follows.

AMV film area (dm ² ) = 35 (dm ² ) × 16.3 / (16.3 + 49.3) = 8.75
ACS film area (dm ² ) = 35 (dm ² ) × 49.3 / (16.3 + 49.3) = 26.25
The AMV film is 8.75 dm ² and the ACS film is 26.25 dm ² .

Each of sulfuric acid and phosphite ions was removed from the plating solution as follows by performing dialysis for 13.11 hours at an electric current of 5 (A) using the electrodialyzer configured at the above ratio.
Sulfate ion = (8.75 × 2.2 + 26.25 × 1.3) × 5 (A) × 13.11 (H) = 3499 (g) ≈3500 (g)
Phosphite ion = (8.75 × 0.9 + 26.25 × 2.6) × 5 (A) × 13.11 (H) = 4996 (g) ≈5000 (g)

As described above, removal target sulfuric acid (3500 g) and phosphite ion (5000 g) were obtained at the same time. In this case, the loss of hypophosphorous acid as an active ingredient was obtained as follows and was 1262 g.
Hypophosphite ion = (8.75 × 0.4 + 26.25 × 0.6) × 5 (A) × 13.11 (H) = 1262 (g)

Comparative Example 1
The electroless NI plating solution volume (100 L) having the same liquid composition as in Example 1 was prepared by using the same apparatus as in Example 1 with an anion exchange membrane area (35 dm ² ) and current (5 A) as an anion exchange membrane only for an AMV membrane. The required dialysis time of each ion when configured with

In order to obtain the target concentrations of sulfuric acid and phosphite ions, the specific ion migration amounts of the AMV membrane described in Example 1 are used (in the case of sulfuric acid).
3500 = 2.2 × 35 × 5 (A) × T1 (H)
T1 = 9.09 (H)
(In the case of phosphorous acid)
5000 = 0.9 × 35 × 5 (A) × T2 (H)
T2 = 31.7 (H)
Thus, the time required for dialysis varies greatly, and either ion is excessive or insufficient.

Further, when obtaining target amounts of sulfuric acid and phosphite ions, dialysis of T2 = 31.7 (H) is required, and the active ingredient hypophosphorous acid is removed by 2219 (g) as obtained by the following formula. And 1.75 times more than Example 1.
Hypophosphite ion = (35 × 0.4) × 5 (A) × 31.7 (H) = 2219 (g)

Comparative Example 2
The required dialysis time of each ion when the anion exchange membrane is composed of only an ACS membrane with the same liquid composition as in Example 1 (100 L), anion exchange membrane area (35 dm ² ), and current (5 A). Asked.

In order to obtain the target concentration of sulfuric acid and phosphite ions, the specific ion transfer amount of the ACS membrane described in Example 1 is used (in the case of sulfuric acid).
3500 = 1.3 × 35 × 5 (A) × T1 (H)
T1 = 15.38 (H)
(In the case of phosphorous acid)
5000 = 2.6 × 35 × 5 (A) × T1 (H)
T2 = 10.99 (H)
Thus, the time required for dialysis varies greatly, and either ion is excessive or insufficient.

In addition, when obtaining target amounts of sulfuric acid and phosphite ions, dialysis of T2 = 15.38 (H) is required, and the active ingredient hypophosphorous acid is removed by 1615 (g) as obtained by the following formula. And 1.28 times more excluded than Example 1.
Hypophosphite ion = (35 × 0.6) × 5 (A) × 15.38 (H) = 1615 (g)

Example 2
Electroless Ni liquid (Ni (D): 5 g / L, Na (A): 50 g / L, Fe (B) of impurity ions: 2 g / L, lead (C): 0.5 g / L using the apparatus of FIG. L, hypophosphorous acid: 20 g / L) 1 L was placed in the desalting chamber, and 1 L of 10 g / L sodium acetate solution was placed in the concentration chamber. A cation exchange membrane Nafion 424 membrane (SI) or a Selemion CMV membrane (SII) having a membrane area of 1 dm ² was formed as a cation membrane for evaluation, an electric quantity of 10 AH was given, and Na (A), iron moved to the concentration chamber (B), lead (C), and Ni (D) ions were measured using a capillary electrophoresis apparatus to obtain a migration amount (g) of each ion corresponding to each film. The results are shown in Table 3.

Subsequently, a specific ion transfer amount (g / (A × H) / dm ² ) or less of each ion in each film was obtained. The results are shown in Table 4.

Using the electrodialyzer shown in FIG. 1 for the plating solution (100 L), the Na concentration (A) is 10 g / L (removal target amount is 4000 g) in order to regenerate unnecessary components as an electroless Ni plating solution. The membrane area of the cation exchange membrane is 35 dm so that the iron concentration (B) is 0.1 g / L (removal target amount is 190 g) and the lead concentration (C) is 0.05 g / L (removal target amount is 45 g). ² was prepared, and the membrane area ratio (CMV / CSO / 424) = (SI / SII / SIII) of the cation exchange membrane when the amount of electricity was Q was determined as follows.

(Na ion)
4000 = (35 × SI × 2.0 + 35 × SII × 1.4 + 35 × SIII × 1.1) × Q
(Iron ion)
190 = (35 × SI × 0.05 + 35 × SII × 0.12 + 35 × SIII × 0.08) × Q
(Lead ion)
45 = (35 × SI × 0.01 + 35 × SII × 0.02 + 35 × SIII × 0.05) × Q
(CMV / CSO / 424) = (SI / SII / SIII) = 35Q / 24.7Q / 8.8Q
By the above, each membrane area ratio with the membrane area of 35 dm ² of the cation exchange membrane is obtained as follows.

CMV membrane area (dm ² ) = 35 (dm ² ) × 35 / (35 + 24.7 + 8.8) = 17.8
CSO film area (dm ² ) = 35 (dm ² ) × 24.7 / (35 + 24.7 + 8.8) = 12.6
424 area (dm ² ) = 35 (dm ² ) × 8.8 / (35 + 24.7 + 8.8) = 4.6
Each membrane area by more than, CMV membranes 17.8dm ^2, CSO film 12.6dm ^2, Nafion film 4.6Dm ² was obtained.

The following removal amount (g) of Na, iron, and lead ions was obtained by performing dialysis for 13.7 hours at a current of 5 A at the above ratio.
Na ion = (17.8 × 2.0 + 12.6 × 1.4 + 4.6 × 1.1) × 5 (A) × 13.7 (H) = 3995 (g) ≈4000 (g)
Iron ion = (17.8 × 0.05 + 12.6 × 0.12 + 4.6 × 0.08) × 5 (A) × 13.7 (H) = 190 (g)
Lead ion = (17.8 × 0.01 + 12.6 × 0.02 + 4.6 × 0.05) × 5 (A) × 13.7 (H) = 45 (g)
As described above, removal target Na (4000 g), iron (190 g) and lead (45 g) ions were obtained simultaneously.

The loss amount of Ni as an active ingredient in this case was obtained by the following formula and was 1973 g.
Ni ion = (17.8 × 0.76 + 12.6 × 0.9 + 4.6 × 0.86) × 5 (A) × 13.7 (H) = 1973 (g)

Comparative Example 3
Necessary dialysis time for each ion when the cation exchange membrane is composed of only a CMV membrane with the same liquid composition as in Example 2 (100 L), cation exchange membrane area (35 dm ² ), and current (5 A). Was determined below.

In order to obtain removal target amounts of Na, Fe, and lead ions, the specific ion migration amount of the CMV film described in Example 2 is used (in the case of Na ions).
4000 = 2.0 × 35 × 5 × T1 (H)
T1 = 11.4 (H)
(In the case of Fe ions)
190 = 0.05 × 35 × 5 × T2 (H)
T2 = 21.7 (H)
(Lead ion)
45 = 0.01 × 35 × 5 × T3 (H)
T3 = 25.7 (H)
Thus, the time required for dialysis varies greatly, and either ion is excessive or insufficient.

Further, when trying to obtain a target removal amount of Na, iron and lead ions, dialysis of T3 = 25.7 (hours) is required, and the removal amount of Ni as an active ingredient is obtained by the following equation, 3418 (g) It was removed and excluded 1.73 times more than Example 1.
Ni ion = (35 × 0.76) × 5 (A) × 25.7 (H) = 3418 (g)

  The electrodialysis apparatus of the present invention simultaneously removes ions to be removed from an electrolyte solution containing a plurality of at least one of anion and cation species that are ions to be removed using an electrodialysis method, and the active ion component. Since there is little loss during dialysis, it can be used to recover valuable components.

It is a conceptual diagram which shows one embodiment of the electrodialysis apparatus of this invention. It is a conceptual diagram which shows the other embodiment of the electrodialysis apparatus of this invention. It is a conceptual diagram which shows the apparatus which calculates | requires the intrinsic | native ion movement amount of a cation exchange membrane. It is a conceptual diagram which shows the apparatus which calculates | requires the intrinsic | native ion movement amount of an anion exchange membrane.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plating liquid 2 Plating tank 3 Electrodialyzer 4 Concentrated liquid 5 Concentrated liquid tank 6,7 Circulating pump 8 Power supply 21 Cation exchange membrane 22 Desalination chamber 23 Concentration chamber 31 Anion exchange membrane 32 Desalination chamber 33 Concentration chamber

Claims (5)

An electrodialysis apparatus that removes the plurality of types of removal target ions in preference to the effective ions by an electrodialysis method from an electrolyte solution containing effective ions and a plurality of types of removal target ions ,
Comprising a plurality of cation exchange membranes and a plurality of anion exchange membranes are dialysis membrane between the anode and the cathode,
At least one of the cation exchange membrane or the anion exchange membrane is configured by overlapping a plurality of sub ion exchange membranes each having a different area,
Wherein the plurality of sub-ion exchange membranes, specific ion movement amount represented by the following formula (1) of the removal target ions have Tsu different respectively,
The specific ion transfer amount of the ions to be removed that the secondary ion exchange membrane has is larger than the specific ion transfer amount of the effective ions that the secondary ion exchange membrane has,
The area ratio of each of the secondary ion exchange membranes is represented by the following formula (2) .
Inherent ion transfer amount (g / (A × H) / dm ² ) = ion transfer amount (g) ÷ electric amount (A × H) ÷ ion exchange membrane area (dm ² ) (1)
(In the formula, the area of the ion exchange membrane indicates the area of one sub ion exchange membrane .)
Formula (2) is shown as follows.
AMI1 = (SA1 × ZA × A1I1 +... + SAN × ZA × ANI1) × Q
AMI2 = (SA1 × ZA × A1I2 +... + SAN × ZA × ANI2) × Q
・
・
AMIn = (SA1 × ZA × A1In +... + SAN × ZA × ANIn) × Q
(Where SA1... SAN is the area ratio of the sub-ion exchange membrane, AMI1... AMIn is the removal target amount (g) of ion n species (I1... In) to be removed, and A1I1. A1In to ANI1... ANIn is a specific ion transfer amount (g / (A × H) for n types of ions to be removed (I1... In) for each of the secondary ion exchange membrane N types (A1... AN) used. ) / Dm ² ), Q is the quantity of electricity during dialysis (A × H), and ZA is the total area (dm ² ) of either the cation exchange membrane or the anion exchange membrane used. .) 2. The specific ion transfer amount of the ions to be removed included in the secondary ion exchange membrane is larger than any of the specific ion transfer amounts of the effective ions included in the secondary ion exchange membrane. Electrodialysis machine. Each of the plurality of cation exchange membranes and the plurality of anion exchange membranes are spaced apart from each other;
The electrodialysis apparatus according to claim 1 or 2, wherein the cation exchange membrane and the anion exchange membrane are alternately arranged. The electrodialysis apparatus according to any one of claims 1 to 3, wherein all of the ions to be removed are anions. The ions to be removed are sulfate ions and phosphite ions,
The electrodialyzer according to any one of claims 1 to 4, wherein the effective ions are hypophosphite ions.

Images