JP7362439B2 - Electrolytic extraction equipment and electrolytic extraction method - Google Patents

Description

Embodiments of the present invention relate to an electrolytic extraction apparatus and an electrolytic extraction method.

Conventionally, as a technique for separating and recovering metals contained in a solution, there is a technique using a centrifugal extraction device, and a technique for adjusting the valence of the solution before extraction is known.

Japanese Patent Application Publication No. 2010-43953

Tomitaro Ishimori, Eiko Nakamura, JAERI-1047 Japan Atomic Energy Research Institute

In addition to centrifugal extraction equipment, there is a technology that uses extraction membranes to separate and recover metals. In the technology for separating and recovering such metals, there is a desire to further improve the extraction efficiency.

The embodiments of the present invention have been made in consideration of such circumstances, and an object of the present invention is to provide an electrolytic extraction technique that can improve the extraction efficiency of metals contained in a solution.

The electrolytic extraction device according to the embodiment of the present invention communicates with the first electrolytic cell and a first electrolytic cell containing a first solution containing metal ions, and the metal ions are transferred from the first electrolytic cell. A second electrolytic cell containing a second solution is provided at a position in contact with the first solution, and by applying a voltage , the valence of the metal ions in the first electrolytic cell is changed to a second electrolytic cell. A first electrode to be adjusted to a specific valence of 1, and an extractant that partitions the inside of the first electrolytic cell and the inside of the second electrolytic cell that are communicated with each other, and adsorbs the metal ions of the first specific valence. an extraction membrane that is impregnated so that the metal ions can move from the first solution in the first electrolytic cell to the second solution in the second electrolytic cell; and an extraction membrane provided at a position in contact with the second solution. , and by applying a voltage , the valence of the metal ions adsorbed on the extraction membrane is changed from the first specific valence that is extractable to the extraction membrane to non-extractable to the extraction membrane. a second electrode that adjusts the metal ion to a second specific valence and desorbs the metal ion from the extraction membrane ; the first specific valence is adjusted by voltage; The adsorption performance of the membrane for the metal ions is improved by applying a voltage to the first electrode, the second specific valence is adjusted by the voltage, and the metal ions of the extraction membrane are improved . The adsorption performance of the liquid is reduced by applying a voltage to the second electrode.

Embodiments of the present invention provide electrolytic extraction techniques that can improve the extraction efficiency of metals contained in a solution.

FIG. 1 is a cross-sectional view showing the electrolytic extraction device of the first embodiment. Graph showing the dependence of the distribution ratio of neptunium on nitric acid concentration. 1 is a flowchart showing the electrolytic extraction method of the first embodiment. FIG. 2 is a cross-sectional view showing an electrolytic extraction device according to a second embodiment. FIG. 3 is a cross-sectional view showing an electrolytic extraction device according to a third embodiment. FIG. 4 is a cross-sectional view showing an electrolytic extraction device according to a fourth embodiment.

(First embodiment)
Hereinafter, embodiments of an electrolytic extraction apparatus and an electrolytic extraction method will be described in detail with reference to the drawings. First, an electrolytic extraction apparatus and an electrolytic extraction method according to a first embodiment will be described using FIGS. 1 to 3.

Reference numeral 1 in FIG. 1 is an electrolytic extraction apparatus of the first embodiment. The electrolytic extraction device 1 includes a first electrolytic cell 2, a second electrolytic cell 3, a first electrode 4, a second electrode 5, a cell connection section 6, an extraction membrane 7, and a control section 8.

The first electrolytic cell 2 and the second electrolytic cell 3 are box-shaped containers. The first electrolytic cell 2 accommodates a first solution 11 containing metal ions M. A second solution 12 is accommodated in the second electrolytic cell 3 . Note that the first solution 11 and the second solution 12 may have liquid compositions with different nitric acid concentrations, or may have liquid compositions with the same nitric acid concentration.

An introduction port 9 is provided in the first electrolytic cell 2 (supply tank). A first solution 11 is supplied from this introduction port 9 . A discharge port 10 is provided in the second electrolytic cell 3 (recovery tank). A second solution 12 containing metal ions M to be recovered is recovered from the outlet 10 .

In addition, in the case of batch processing, the solution inside the first electrolytic cell 2 and the inside of the second electrolytic cell 3 may be pumped out and replaced. For example, when pumping out the solution from the first electrolytic cell 2, the inlet 9 can serve as the outlet. Moreover, when introducing a solution into the second electrolytic cell 3, the discharge port 10 can serve as an introduction port.

Furthermore, the introduction and discharge of the first solution 11 into and out of the first electrolytic tank 2 (supply tank) may be carried out continuously. For example, the first electrolytic cell 2 is provided with an outlet in addition to the inlet 9, and the first solution 11 is continuously introduced through the inlet 9 and the first solution 11 is continuously discharged through the outlet. You can also do it.

Furthermore, the introduction and discharge of the second solution 12 into and out of the second electrolytic tank 3 (recovery tank) may be carried out continuously. For example, the second electrolytic cell 3 is provided with an inlet in addition to the outlet 10, and the second solution 12 is continuously introduced from the inlet and the second solution 12 is continuously discharged from the outlet 10. You can also do it.

The tank connection part 6 connects the first electrolytic tank 2 and the second electrolytic tank 3 in a state where they can communicate with each other. An extraction membrane 7 is provided at this tank connection part 6. The inside of the first electrolytic cell 2 and the inside of the second electrolytic cell 3 are separated by an extraction membrane 7. By being separated by the extraction membrane 7, the first solution 11 in the first electrolytic cell 2 and the second solution 12 in the second electrolytic cell 3 are prevented from mixing. This extraction membrane 7 is impregnated with an extractant that adsorbs metal ions M.

The extraction membrane 7 is a plate-like (film-like) member made of porous resin or the like that can be impregnated with an extractant. Metal ions M can move from the first solution 11 of the first electrolytic cell 2 to the second solution 12 of the second electrolytic cell 3 via this extraction membrane 7 . Note that the extraction membrane 7 may be made of ion exchange resin.

The first electrode 4 is provided inside the first electrolytic cell 2 . The second electrode 5 is provided inside the second electrolytic cell 3. The control unit 8 supplies power to the first electrode 4 and the second electrode 5, and converts the metal substances contained in the first solution 11 and the second solution 12 into metal ions M of a predetermined valence (atomic valence, ionic valence). Performs control to

The electrolytic extraction device 1 of this embodiment improves extractability and non-extractability by adjusting the valence of metal ions M contained in the first solution 11 and the second solution 12 using the first electrode 4 and the second electrode 5. It can be an extractable metal ion M. Then, metal ions M to be separated and recovered are efficiently extracted via the extraction membrane 7.

Substances such as cerium (Ce), which is being considered as a decontamination agent for dissolution tanks or piping for reprocessing effectiveness, and plutonium (Pu) and neptunium (Np), which are important in consideration of environmental impact, are chemically classified by valence. Character changes. By adjusting the valence of these substances, the extraction performance changes. Therefore, this performance is utilized to extract a predetermined substance contained in the solution. In addition, it is possible to efficiently and selectively extract substances whose valence changes in an aqueous solution such as selenium (Se), tellurium (Te), and thallium (Tl) by utilizing the change in valence. Become.

In order to exhibit these effects, the adsorption performance of the metal ions M adsorbed on the extraction membrane 7 is improved by adjusting the electrolytic valence of the metal ions M at the first electrode 4 of the first electrolytic cell 2. I can do it. Therefore, the performance of extracting metal ions M from the first electrolytic cell 2 by the extraction membrane 7 can be improved. Furthermore, when multiple types of metal ions M are included in the first solution 11, only the metal ions M to be separated and recovered can be selectively extracted using the extraction membrane 7.

Furthermore, by adjusting the electrolytic valence of the metal ions M at the second electrode 5 of the second electrolytic cell 3, the adsorption performance of the metal ions M adsorbed by the extraction membrane 7 can be reduced. Therefore, the performance of moving metal ions M from the extraction membrane 7 to the second electrolytic cell 3 can be improved. Thereby, the extraction efficiency is synergistically improved by the extraction by the extraction membrane 7 and the back extraction.

Furthermore, in this embodiment, the injection of a drug, which was necessary for valence adjustment in the conventional technique, is no longer necessary, and the influence of the drug due to valence adjustment can be eliminated. Therefore, based on the adjustment of the electrolytic valence of the metal ion M, the property of the extraction membrane 7 in which the extraction performance improves and decreases can be utilized together with the drug.

Furthermore, with conventional techniques, efficient extraction was not possible because the valence of metal ions was not adjusted. Even if the metal ions are adsorbed onto the extraction membrane as extractable metal ions, it may be difficult to back-extract the metal ions from the extraction membrane. This embodiment can solve such problems.

By adjusting the valence of the metal ions M on the first electrolytic cell 2 side and the second electrolytic cell 3 side, the metal ions M can be efficiently removed by the synergistic effect between the adsorption side and the desorption side of the extraction membrane 7. Can be extracted and separated. That is, in the electrolytic extraction apparatus 1 of this embodiment, the extraction rate or separation coefficient can be improved compared to the conventional technology. Further, by adjusting the electrolytic valence of the metal ion M, the extraction performance can be improved without adding a reagent. In addition, by processing with an extracted valence after processing with a non-extracted valence, the recovered material (metal ion M) can be made highly pure. Furthermore, even when the first solution 11 and the second solution 12 contained in the first electrolytic cell 2 and the second electrolytic cell 3 use the same matrix, separation can be performed using the difference in valence.

As shown in FIG. 1, the first electrode 4 applies a predetermined voltage to the first solution 11 in the first electrolytic cell 2, thereby increasing the valence of the metal ion M1 contained in the first solution 11. 1 Adjust to a specific valence. The extractant with which the extraction membrane 7 is impregnated has the property of adsorbing metal ions of the first specific valence. That is, the extraction membrane 7 adsorbs the metal ion M1 of the first specific valence contained in the first solution 11 of the first electrolytic cell 2.

The second electrode 5 applies a predetermined voltage to the second solution 12 in the second electrolytic cell 3, thereby converting the valence of the metal ions M2 adsorbed onto the extraction membrane 7 into a valence different from the first specific valence. 2 Adjust to a specific valence. The extraction membrane 7 has a property of desorbing the metal ion M2 of the second specific valence. That is, the metal ions M2 of the second specific valence desorbed from the extraction membrane 7 move to the second solution 12 inside the second electrolytic cell 3.

The extractant of the extraction membrane 7 has a higher adsorption rate for the metal ions M1 having the first specific valence than the adsorption rate for the metal ions M2 having the second specific valence. In this way, the metal ions M1 of the first specific valence in the first electrolytic cell 2 are easily adsorbed by the extraction membrane 7. In addition, the metal ions M2 adsorbed on the extraction membrane 7 change to the second specific valence, making them easier to desorb from the extraction membrane 7. Therefore, the extraction efficiency of metal ions M can be improved.

In the first electrode 4 and the second electrode 5 of the first embodiment, a plurality of disk portions are provided near the tip of a rod member. In this way, the surface areas of the first electrode 4 and the second electrode 5 can be increased. Moreover, the first electrode 4 and the second electrode 5 are formed of a porous material. In this way, the surface areas of the first electrode 4 and the second electrode 5 can be increased, and voltage can be efficiently applied to the metal ions M. Note that at least one of the first electrode 4 and the second electrode 5 may be made of a porous material.

Next, a specific embodiment will be described. An example of the metal ion M to be separated and recovered is neptunium. An example of the extractant impregnated into the extraction membrane 7 is tributyl phosphate. Note that the metal ions M may target other substances. Other substances may be used as the extractant.

FIG. 2 is a graph showing the dependence of the distribution ratio of neptunium from the organic solvent of 30 vol % tributyl phosphate on the nitric acid concentration. As shown in this graph, for example, spent fuel is dissolved in approximately 3 mol/L nitric acid to form an acid solution. Here, neptunium can have a valence of four (Np(IV)), five (Np(V)), and six (Np(VI)). A voltage is applied to this acid solution so that the potential is 0.94 V vs. SSE (SSE: silver-silver chloride reference electrode) or higher.

Further, by further increasing the nitric acid concentration, neptunium can be oxidized to hexavalent (Np(VI)) more efficiently. By adjusting the valence of neptunium, it is possible to unify the distribution ratio (distribution ratio = (concentration of target metal in organic solvent) / (concentration of target metal in aqueous solution)), which differs depending on each valence, so that organic solvent and Distribution into aqueous solutions can be controlled.

In the first embodiment, the valence of neptunium, which is the metal ion M, is adjusted. Here, the first specific valence is set as hexavalence (Np(VI)), and the second specific valence is set as quintuvalence (Np(V)).

In the first embodiment, the first electrode 4 is connected to the positive electrode of a DC power source and serves as an anode. Further, the second electrode 5 is connected to the negative electrode of the DC power source and becomes a cathode.

The first electrode 4 (anode) of the first electrolytic cell 2 adjusts the metal ion M1 to be hexavalent (Np(VI)) as a first specific valence. This metal ion M1 is adsorbed on the extraction membrane 7 impregnated with an extractant. Then, the second electrode 5 (cathode) of the second electrolytic cell 3 adjusts the metal ions M2 adsorbed on the extraction membrane 7 to be pentavalent (Np(V)) as a second specific valence. When the metal ions M2 reach the second specific valence, they are desorbed from the extraction membrane 7 and move to the second solution 12 in the second electrolytic cell 3.

In this way, the second solution 12 in the second electrolytic cell 3 contains only the metal ions M to be separated and recovered. That is, only the metal ions M can be separated and recovered from the first solution 11 in the first electrolytic cell 2.

Note that other embodiments may also be used. For example, as a modification, when adjusting the valence of neptunium, which is the metal ion M, the first specific valence is set to 4 (Np(IV)), and the second specific valence is set to 5 (Np(V)). ) may also be used.

In this modification, the first electrode 4 is connected to the negative electrode of a DC power source and serves as a cathode. Further, the second electrode 5 is connected to the positive electrode of the DC power source and serves as an anode.

The first electrode 4 (cathode) of the first electrolytic cell 2 adjusts the metal ion M1 to have a valence of four (Np(IV)) as a first specific valence. This metal ion M1 is adsorbed on the extraction membrane 7 impregnated with an extractant. Then, the second electrode 5 (anode) of the second electrolytic cell 3 adjusts the metal ions M2 adsorbed to the extraction membrane 7 to be pentavalent (Np(V)) as a second specific valence. When the metal ions M2 reach the second specific valence, they are desorbed from the extraction membrane 7 and move to the second solution 12 in the second electrolytic cell 3.

Note that the metal ion M to be separated and recovered may be a substance other than neptunium. For example, as shown in Non-Patent Document 1 (JAERI-1047 Japan Atomic Energy Research Institute), it has been reported that in a 100% TBP-HCl system, the distribution ratios of Se, Te, and Tl vary greatly depending on their valences. .

It is expected that these metals can be efficiently separated and recovered. For example, in 8 to 10 M HCl, Se (IV), Te (IV), and Tl (III) become metal ions M that have a high distribution ratio and are easy to extract. By adjusting the valence using the electrolytic extraction device 1 of this embodiment, these metal ions M can be separated and recovered from a predetermined first solution 11. Note that cerium (Ce) may be separated and recovered.

Furthermore, Se(VI), Te(VI), and Tl(i) are metal ions M that have low distribution ratios and are difficult to extract. Using these characteristics, it becomes possible to separate these metal ions M from cesium (Cs), which is not extractable under any conditions. Furthermore, by adjusting the electrolytic conditions, it is also possible to separate them. It is also possible to retain these elements with the extraction capacity, and it is possible to provide selectivity depending on the conditions of each electrolytic cell.

Further, when the first solution 11 contained in the first electrolytic cell 2 contains multiple types of metal ions M, only the specific type of metal ions M are adjusted to have a valence of the first specific valence. You can do it like this. For example, if neptunium is set as a specific type of metal ion M to be separated and recovered from the first solution 11, and a metal substance other than neptunium is contained in the first solution 11, only the valence of neptunium is determined. The first specific valence is set to be adsorbable to the extraction membrane 7. Further, only the valence of neptunium contained in the second solution 12 is set to a second specific valence that can be desorbed from the extraction membrane 7. In this way, only a specific type of metal ion M can be separated and recovered by appropriately adjusting the valence.

Furthermore, metal ions M other than the specific type may be adjusted to have a valence other than the first specific valence. In this way, metal ions M other than the specific type are not adsorbed by the extraction membrane 7. Note that the mode in which the metal ion M is adjusted to a valence other than the first specific valence includes a mode in which no voltage is applied by the first electrode 4. Furthermore, it includes a mode in which a voltage is applied by the first electrode 4 to adjust the valence to a value other than the first specific valence.

Further, metal ions M other than the specific type may be adjusted to a valence other than the second specific valence. In this way, metal ions M other than the specific type do not have to be desorbed from the extraction membrane 7. Note that the mode in which the metal ion M is adjusted to a valence other than the second specific valence includes a mode in which no voltage is applied by the second electrode 5. Furthermore, it includes a mode in which a voltage is applied by the second electrode 5 to adjust the valence to a value other than the second specific valence.

Next, the electrolytic extraction method executed by the electrolytic extraction apparatus 1 of the first embodiment will be described using the flowchart of FIG. 3. A description will be given including the effects passively produced by the operation of this electrolytic extraction device 1. Note that FIG. 1 will be referred to as appropriate.

First, in step S11, the operator stores the first solution 11 containing metal ions M in the first electrolytic bath 2. Further, the second solution 12 is stored in the second electrolytic bath 3 .

In the next step S12, the control unit 8 applies a predetermined voltage to the first solution 11 in the first electrolytic cell 2 to adjust the valence of the metal ion M1 contained in the first solution 11 to a first characteristic. Adjust to list price.

In the next step S13, the metal ion M1 of the first specific valence is adsorbed by the extraction membrane 7 impregnated with an extractant having the property of adsorbing the metal ion M1 of the first specific valence.

In the next step S14, the control unit 8 applies a predetermined voltage to the second solution 12 in the second electrolytic cell 3 to change the valence of the metal ions M2 adsorbed on the extraction membrane 7 to a first specific value. Adjust to a second specific valence different from the number.

In the next step S15, the metal ions M2 of the second specific valence desorbed from the extraction membrane 7 move to the second solution 12 accommodated in the second electrolytic cell 3. In this way, the metal ions M contained in the first solution 11 can be separated and recovered.

Note that although the flowchart of this embodiment shows an example in which each step is executed in series, the sequential relationship of each step is not necessarily fixed, and even if the sequential relationship of some steps is swapped. good. Also, some steps may be executed in parallel with other steps.

(Second embodiment)
Next, an electrolytic extraction apparatus 1A and an electrolytic extraction method according to the second embodiment will be described using FIG. 4. Note that the same components as those shown in the embodiments described above are given the same reference numerals and redundant explanations will be omitted.

In the electrolytic extraction device 1A of the second embodiment, the first electrode 4A and the second electrode 5A are provided outside the first electrolytic cell 2 and the second electrolytic cell 3.

The first electrolytic cell 2 is connected to the first electrode 4A via a circulation pipe 14. Further, a circulation pump 16 is provided that circulates the first solution 11 between the first electrolytic cell 2 and the first electrode 4A.

The second electrolytic cell 3 is connected to the second electrode 5A via a circulation pipe 15. Further, a circulation pump 17 is provided that circulates the second solution 12 between the second electrolytic cell 3 and the second electrode 5A.

The first electrode 4A and the second electrode 5A have a box shape. A voltage can be applied to the metal ions M contained in the solutions 11 and 12 passing through each of them. The metal ions M1 contained in the first solution 11 passing through the first electrode 4A are adjusted to have a first specific valence. The metal ions M2 contained in the second solution 12 passing through the second electrode 5A are adjusted to a second specific valence. Note that the circulation pumps 16 and 17 may be controlled by the control section 8.

The extraction membrane 7 adsorbs metal ions M1 of a first specific valence contained in the first solution 11 of the first electrolytic cell 2 . Then, the metal ions M2 of the second specific valence desorbed from the extraction membrane 7 move to the second solution 12 inside the second electrolytic cell 3. Therefore, the extraction efficiency of metal ions M can be improved.

In the second embodiment, since the solutions 11 and 12 are circulated between the electrodes 4A and 5A and the electrolytic cells 2 and 3, respectively, the valence of the metal ion M is adjusted throughout the solutions 11 and 12. be able to.

(Third embodiment)
Next, an electrolytic extraction apparatus 1B and an electrolytic extraction method according to a third embodiment will be described using FIG. 5. Note that the same components as those shown in the embodiments described above are given the same reference numerals and redundant explanations will be omitted.

In the electrolytic extraction device 1B of the third embodiment, the first electrode 4B and the second electrode 5B form a mesh shape and are arranged so as to sandwich the extraction membrane 7 therebetween. That is, the first electrode 4B is arranged so as to extend along one surface of the extraction membrane 7, and the second electrode 5B is arranged so as to extend along the other surface of the extraction membrane 7. Note that the first electrode 4B and the second electrode 5B may be in contact with the extraction membrane 7 or may be provided near the extraction membrane 7.

In the third embodiment, the electrodes 4B and 5B are arranged facing each other on the extraction membrane 7, so that the metal ions M whose valences have been adjusted by the electrodes 4B and 5B easily react with the extraction membrane 7. . Then, adsorption and desorption of metal ions M are efficiently performed on both sides of the extraction membrane 7.

(Fourth embodiment)
Next, an electrolytic extraction apparatus 1C and an electrolytic extraction method of the fourth embodiment will be described using FIG. 6. Note that the same components as those shown in the embodiments described above are given the same reference numerals and redundant explanations will be omitted.

In the electrolytic extraction device 1C of the fourth embodiment, a box-shaped first electrode 4C is provided outside the first electrolytic cell 2. The first electrolytic cell 2 is connected to the first electrode 4C via a circulation pipe 14. Further, a circulation pump 16 is provided that circulates the first solution 11 between the first electrolytic cell 2 and the first electrode 4C.

Further, a second electrode 5C having a mesh shape is arranged so as to spread along one surface of the extraction membrane 7. Note that the second electrode 5C may be in contact with the extraction membrane 7 or may be provided near the extraction membrane 7.

In the fourth embodiment, since the first solution 11 is circulated between the first electrode 4C and the first electrolytic cell 2, the metal ions M1 are adjusted to the first specific valence throughout the first solution 11. can do. Furthermore, since the second electrode 5C is arranged to face the extraction membrane 7, the metal ions M2 adjusted to the second specific valence by the second electrode 5C are easily desorbed from the extraction membrane 7.

Although the electrolytic extraction apparatus and electrolytic extraction method according to the present embodiment have been described based on the first to fourth embodiments, the configuration applied in any one embodiment may also be applied to other embodiments. Alternatively, the configurations applied in each embodiment may be combined.

According to at least one embodiment described above, the extraction efficiency of metals contained in the solution is improved by including the first electrode that adjusts the valence of metal ions in the first electrolytic cell to the first specific valence. can be done.

Although several embodiments of the invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, changes, and combinations can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention as well as within the scope of the invention described in the claims and its equivalents.

1 (1A, 1B, 1C)...electrolytic extraction device, 2...first electrolytic cell, 3...second electrolytic cell, 4 (4A, 4B, 4C)...first electrode, 5 (4A, 4B, 4C)...first 2 electrodes, 6...tank connection part, 7...extraction membrane, 8...control unit, 9...inlet, 10...outlet, 11...first solution, 12...second solution, 14, 15...circulation pipe, 16, 17... Circulation pump, M (M1, M2)... Metal ion.

Claims (8)

a first electrolytic cell containing a first solution containing metal ions;
a second electrolytic cell communicating with the first electrolytic cell and containing a second solution in which the metal ions are transferred from the first electrolytic cell;
a first electrode that is provided at a position in contact with the first solution and adjusts the valence of the metal ions in the first electrolytic cell to a first specific valence by applying a voltage ;
The inside of the first electrolytic cell and the inside of the second electrolytic cell which are communicated with each other are impregnated with an extractant that adsorbs the metal ions of the first specific valence. an extraction membrane that allows the metal ions to move from the solution to the second solution in the second electrolytic cell ;
It is provided at a position in contact with the second solution, and by applying a voltage , the valence of the metal ions adsorbed on the extraction membrane is transferred to the first characteristic that is extractable with respect to the extraction membrane. a second electrode that adjusts the fixed valence to a second specific valence that is non-extractable with respect to the extraction membrane and desorbs the metal ions from the extraction membrane ;
Equipped with
The first specific valence is adjusted by voltage, and the adsorption performance of the extraction membrane for the metal ions is improved by applying a voltage to the first electrode.
The second specific valence is adjusted by voltage, and the adsorption performance of the extraction membrane for the metal ions is reduced by applying a voltage to the second electrode.
Electrolytic extraction equipment. The extractant used is one in which the adsorption rate of the metal ions of the first specific valence is higher than the adsorption rate of the metal ions of the second specific valence;
The electrolytic extraction device according to claim 1. The first solution contained in the first electrolytic cell contains a plurality of types of metal ions,
By adjusting the applied voltage using the first electrode, the valence of the first specific valence that allows the extraction membrane to adsorb the specific type of metal ion contained in the first solution. adjust to,
The electrolytic extraction apparatus according to claim 1 or 2. Adjusting the applied voltage using the first electrode to adjust the metal ions other than the specific type contained in the first solution to a valence other than the first specific valence;
The electrolytic extraction device according to claim 3. at least one of the first electrode and the second electrode is a porous material;
The electrolytic extraction device according to any one of claims 1 to 4. At least one of the first electrode and the second electrode has a mesh shape, spreads along the surface of the extraction membrane, and is disposed in contact with the extraction membrane or in the vicinity of the extraction membrane.
The electrolytic extraction device according to any one of claims 1 to 5. the first electrode and the second electrode form the mesh shape and are arranged at positions sandwiching the extraction membrane;
The electrolytic extraction device according to claim 6. accommodating a first solution containing metal ions in a first electrolytic cell;
adjusting the valence of the metal ions in the first electrolytic cell to a first specific valence by applying a voltage to the first solution;
Extraction in which the metal ions are impregnated with an extractant that adsorbs the metal ions of the first specific valence, and the metal ions can be transferred from the first solution in the first electrolytic cell to the second solution in the second electrolytic cell. a step in which the metal ion of the first specific valence that is extractable with respect to the extraction membrane is adsorbed to the membrane;
By applying a voltage to the second solution contained in the second electrolytic cell, the valence of the metal ions adsorbed on the extraction membrane is changed from the first specific valence to the extraction membrane. adjusting the metal ion to a non-extractable second specific valence and desorbing the metal ion from the extraction membrane ;
moving the metal ions of the second specific valence desorbed from the extraction membrane to the second solution;
including;
The first specific valence is adjusted by voltage, and the adsorption performance of the extraction membrane for the metal ions is improved by applying a voltage to the first solution.
The second specific valence is adjusted by voltage, and the adsorption performance of the extraction membrane for the metal ions is reduced by applying a voltage to the second solution.
Electrolytic extraction method.

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