JP6348235B2 - Vanadium recovery processing method and use of vanadium - Google Patents

Description

  The present invention relates to a vanadium recovery processing method and use of vanadium, and more particularly to a vanadium recovery processing method and vanadium use that can recover vanadium at low cost.

  Secondary batteries are attracting attention as a large-scale energy storage source in place of pumped-storage power generation facilities that are difficult to construct due to the location conditions. In particular, a vanadium redox flow battery using a vanadium electrolyte has advantages such as easy battery maintenance and long life.

  Vanadium pentavalent and tetravalent redox pairs are used for the positive electrode active material liquid of the vanadium redox flow battery, and vanadium divalent and trivalent redox pairs are used for the negative electrode active material liquid (Patent Document 1). 2).

  Conventionally, vanadium used as an active material of a redox battery has been recovered from vanadium resources such as ore. For this reason, resource depletion and economic efficiency in areas where resources are scarce become problems.

JP 62-186473 A Japanese Patent Laid-Open No. 4-28671

  Then, the subject of this invention is providing vanadium collection | recovery processing method and use of vanadium which can collect | recover vanadium at low cost.

  Other problems of the present invention will become apparent from the following description.

  The above problems are solved by the following inventions.

1.
Vanadium is recovered using a vanadium recovery device in which a diaphragm (13) is disposed between an anode chamber (14) provided with an anode (11) and a cathode chamber (15) provided with a cathode (12). When
Supplying the cathode chamber (15) with fly ash wetted by water with high-oxidized vanadium and water containing alkali;
In a state where an aqueous solution containing an electrolyte for recovering the vanadium is supplied to the anode chamber (14), a potential is applied to the anode (11) and the cathode (12) by applying a potential, A vanadium recovery treatment method characterized in that vanadate ions having negative charges in fly ash are passed through the diaphragm (13) and recovered in the aqueous solution in the anode chamber (14) to obtain a vanadium recovery solution. .
2.
2. The method for recovering vanadium according to 1 above, wherein the wet fly ash is pressurized in a range of 0.1 MPa to 1.0 MPa under a potential gradient.
3.
3. The vanadium recovery processing method according to 1 or 2 above, wherein the diaphragm is a microporous membrane.
4).
4. The vanadium recovery treatment method according to 1, 2, or 3, wherein the vanadium recovery liquid containing vanadate ions recovered in the aqueous solution in the anode chamber (14) is concentrated by a reverse osmosis membrane method.
5.
Use of vanadium characterized by using vanadium recovered by the vanadium recovery processing method according to any one of 1 to 4 as an active material of a redox battery.

  ADVANTAGE OF THE INVENTION According to this invention, vanadium collection | recovery processing method and use of vanadium which can collect | recover vanadium at low cost can be provided.

The block diagram explaining an example of the vanadium collection | recovery processing method of this invention The figure which illustrates notionally an example of the vanadium collection | recovery apparatus which can be used suitably for the 1st aspect of the separation process 2 The figure which illustrates notionally an example of the vanadium collection | recovery apparatus which can be used suitably for the 2nd aspect of the separation process 2.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram illustrating an example of a method for producing a vanadium concentrate according to the present invention.

  In FIG. 1, 1 is a hydration process, 2 is a separation process, 3 is a concentration process.

  The fly ash serving as the vanadium recovery source is not particularly limited as long as it is a fly ash containing vanadium, and for example, ash generated with combustion of fossil fuels such as petroleum and coal can be preferably used. Specific examples include incineration ash and fly ash. The fly ash can be collected from the combustion gas using a dust collector such as an electric dust collector or a bag filter.

  The vanadium content of fly ash is not particularly limited. For example, vanadium is preferably contained in a range of 1% by weight to 10% by weight on a dry base, and contained in a range of 2% by weight to 5% by weight on a dry base. More preferably.

  First, in the hydration step 1, water is added to fly ash.

  The amount of water added to the fly ash is not particularly limited as long as it is in a wet state to which vanadium can be moved by the potential gradient formed in the subsequent separation step 2. If the fly ash is originally wet, the water addition step 1 can be omitted as appropriate.

  The moisture content of the wet fly ash is preferably 30% by weight or more, and more preferably in the range of 40% by weight to 90% by weight.

  It is also preferable to add pure water to fly ash. According to the experiment by the present inventors, it has been confirmed that the pH of fly ash to which pure water has been added is about 5.5. This is thought to be due to the presence of sulfuric acid. When pure water is added, since the salt concentration is low, a reverse osmosis membrane (RO membrane) method described later is suitable as the latter membrane separation method.

  In order to improve the conductivity (conductivity) of fly ash, it is preferable that the water to be added contains one or more selected from acids, alkalis and salts thereof. By hydrolyzing fly ash with water containing such an electrolyte, the conductivity (conductivity) of fly ash can be improved, and a potential gradient in the subsequent separation step 2 can be stably formed. An effect of promoting the separation of vanadium is obtained.

  Although an acid is not specifically limited, For example, hydrochloric acid, a sulfuric acid, etc. can be mentioned.

  The alkali is not particularly limited, and examples thereof include sodium hydroxide and calcium hydroxide.

  Although salt is not specifically limited, For example, a sulfate radical etc. can be mentioned, More specifically, calcium sulfate, sodium sulfate, ammonium sulfate etc. can be mentioned.

  In the case of vanadium recovery, it is also preferable to add a substance having an effect of capturing a substance other than vanadium.

  In addition, since fly ash can contain the component which can become an electrolyte from the first, addition of an electrolyte can be abbreviate | omitted suitably.

In wet fly ash, vanadium exists in an ionized state, and exists as a suspension of colloid or the like. In the case of fly ash, both of these are in a higher order oxidation state. In many cases, ionized vanadium is present in a polynuclear form, for example, as vanadium oxide ions (also referred to as vanadate ions) such as metavanadate ions (VO ₃ ⁻ ).

  Next, in the separation step 2, a recovered liquid containing vanadium in water is obtained from the wet fly ash.

  In the separation step 2, the wet fly ash is placed under (a) a potential gradient, (b) pressurized in the range of 0.1 MPa to 1.0 MPa, or (c) 0.1 MPa to 1.MPa under the potential gradient. The recovered liquid is preferably obtained by pressurizing in the range of 0 MPa.

  In the first aspect of the separation step 2 described below with reference to FIG. 2, a case will be described in which a recovered liquid containing vanadium in water is obtained from wet fly ash by a potential gradient.

  FIG. 2 is a diagram conceptually illustrating an example of a vanadium recovery apparatus that can be suitably used in the first aspect of the separation step 2.

  As shown in FIG. 2, the vanadium recovery apparatus can have an electrochemical cell structure including an anode 11 and a cathode 12. Although the material of the anode 11 and the cathode 12 is not particularly limited, for example, glassy carbon or the like can be preferably used.

  A diaphragm 13 is provided between the anode 11 and the cathode 12. The diaphragm 13 isolates the space in the cell into an anode chamber 14 provided with the anode 11 and a cathode chamber 15 provided with the cathode 12. As the diaphragm 13, for example, a microporous membrane such as an MF membrane or an ion exchange membrane can be used.

  A gap corresponding to each of the anode chamber 14 and the cathode chamber 15 can be secured by the spacer S.

  The vanadium recovery device has a recovery liquid inlet 14a for allowing a recovery liquid for recovering vanadium to flow into the anode chamber 14, and a recovery for allowing the recovery liquid containing vanadium separated from fly ash to flow out of the anode chamber 14. And a liquid outlet 14b.

  As the recovery liquid supplied to the anode chamber 14, an aqueous solution containing an electrolyte can be used. The electrolyte is not particularly limited, but for example, sulfuric acid or the like can be preferably used.

  In the vanadium recovery apparatus having the above-described configuration, the wet ash is supplied to the cathode chamber 15 and the anode 11 and the cathode 12 are energized to apply a voltage with the recovery liquid supplied to the anode chamber 14. As a result, vanadate ions having a negative charge in the fly ash are attracted to the anode 11 by the potential gradient between the anode 11 and the cathode 12, pass through the diaphragm 13, and are collected in the collected liquid in the anode chamber 14. Collected.

  In this embodiment, the cathode chamber 15 to which fly ash is supplied is formed as a layered gap between the cathode 12 and the diaphragm 13 arranged to face each other. The width of the layered gap (the distance between the cathode 12 and the diaphragm 13) is set to 5 mm or less. The fly ash is filled in the layered gaps constituting the cathode chamber 15 to form a layer having a thickness of 5 mm or less, and is exposed to a potential gradient in this state. Thus, the effect which can improve the collection | recovery efficiency of vanadium is acquired by making fly ash into the layer form of thickness 5mm or less.

  It is preferable to form a stacked cell by stacking a plurality of cell structures (single cells) shown in FIG. In this case, it is particularly preferable to use a bipolar plate (also referred to as a bipolar plate) as the anode 11 and the cathode 12 and to stack each single cell electrically in series.

  The method for supplying fly ash to the cathode chamber 15 is not particularly limited, and may be a batch type such as a filter press type or a continuous type such as a belt press type.

  The method of supplying the recovered liquid to the anode chamber 14 is not particularly limited, and may be a batch type or a continuous type. Further, the recovery liquid containing vanadium that has flowed out of the anode chamber 14 may be supplied to the anode chamber 14 again. Thus, by performing vanadium collection | recovery, circulating a collection | recovery liquid, the total vanadium ion concentration collect | recovered by a collection | recovery liquid can be raised, and the load in the latter concentration process 3 can be reduced.

  In the separation step 2, the fly ash after the vanadium is separated can be appropriately treated, and can be an industrial product such as a concrete admixture.

  In the first aspect of the separation step 2, the total salt concentration in the recovered liquid can be kept very low by separating vanadium by the potential gradient. Therefore, the effect that the concentration by the membrane separation method in the concentration step 3 can be increased is obtained. From the viewpoint of remarkably exhibiting such effects, the total salt concentration of the recovered liquid is preferably 5M or less, and more preferably 3M or less. Further, the total vanadium concentration of the recovered liquid can be about 2.5M at maximum.

  In the concentration step 3, the recovered liquid containing vanadium is concentrated by a membrane separation method. Thereby, the vanadium concentrate which raised all vanadium ion concentration is obtained.

  The membrane separation method is not particularly limited as long as it can be concentrated so as to increase the total vanadium ion concentration. For example, when the salt concentration is high, the ion dialysis method is suitable, and when the salt concentration is low, The reverse osmosis membrane (RO membrane) method and the like are suitable. In the case of the reverse osmosis membrane (RO membrane) method, it is also preferable to provide it in multiple stages.

  The separated water produced by the membrane separation method can be reused as reclaimed water, and can be used as water to be added to fly ash in the hydration step 1, for example.

  The vanadium concentrate obtained by the concentration step 3 preferably has a total vanadium ion concentration of 2M or more.

  In the concentration step 3, since the membrane separation method is used, an effect of purifying vanadium can be obtained. In particular, if an ion dialysis method or a low-pressure reverse osmosis membrane method is used, an effect of suitably removing metal impurities other than vanadium derived from fly ash can be obtained.

  The vanadium concentrate can be appropriately adjusted so as to be preferably used as a vanadium electrolyte for a redox battery.

  As specific adjustment contents, for example, adjustment of total vanadium ion concentration, adjustment of valence of vanadium ions, adjustment of sulfuric acid concentration, and the like can be preferably exemplified.

  First, adjustment of the total vanadium ion concentration will be described. If the total vanadium ion concentration of the vanadium concentrate is less than the desired concentration (preferably a desired concentration of 1.5 M or more), the vanadium concentrate is returned to the concentration step 3 and subjected to concentration treatment again. Is preferably adjusted to a desired concentration. As another embodiment, the vanadium in an insufficient amount relative to the desired concentration may be added to adjust the total vanadium ion concentration to the desired concentration. On the other hand, when the total vanadium ion concentration of the vanadium concentrate exceeds the desired concentration, it can be adjusted to the desired concentration by adding water and diluting.

  Next, adjustment of the valence of vanadium ions will be described. Adjustment of the valence of vanadium ions contained in the vanadium concentrate can be performed by oxidation or reduction of vanadium ions. The valence adjusted here may be an average of the valences of all vanadium ions contained in the vanadium concentrate. Oxidation or reduction may be performed electrochemically by supplying the vanadium concentrate to an electrolytic cell, or may be performed chemically by adding an oxidizing agent or a reducing agent to the vanadium concentrate.

  As one method of adjusting the valence, first, the vanadium concentrate is supplied to the cathode of the electrolytic cell and electrolyzed, and the valence of vanadium ions contained in the vanadium concentrate is reduced to 3.5. Next, the obtained 3.5-valent vanadium concentrate is supplied to the cathode and anode of the electrolytic cell for electrolysis, and the cathode is adjusted to reduce the valence by reduction and the anode is adjusted to increase the valence by oxidation. Can do. As a result, a negative electrode vanadium concentrated liquid suitably used as a negative electrode active material liquid for a redox battery is obtained at the cathode, while a positive electrode vanadium concentrated liquid suitably used as a positive electrode active material liquid for a redox battery is obtained at the anode. can get. When the vanadium concentrate for negative electrode and the vanadium concentrate for positive electrode thus obtained are supplied to the same redox battery as the negative electrode active material liquid and the positive electrode active material liquid, the effect of excellent valence balance between the positive and negative electrodes is obtained. .

  Next, adjustment of the sulfuric acid concentration will be described. When the sulfuric acid concentration of the vanadium concentrate is less than the desired concentration, the sulfuric acid concentration can be adjusted to the desired concentration by adding a deficient amount of sulfuric acid to the desired concentration. On the other hand, when the sulfuric acid concentration of the vanadium concentrate exceeds the desired concentration, it can be adjusted to the desired concentration by adding water and diluting.

  It is also preferable to automate each adjustment described above by monitoring the total vanadium ion concentration, vanadium ion valence, sulfuric acid concentration, etc. of the vanadium concentrate.

  Next, a second aspect of the separation step 2 will be described with reference to FIG. In the second aspect of the separation step 2, a case where a recovered liquid containing vanadium in water is obtained by pressurizing wet fly ash under a potential gradient will be described.

  FIG. 3 is a diagram conceptually illustrating an example of a vanadium recovery apparatus that can be suitably used in the second aspect of the separation step 2.

  As shown in FIG. 3, the vanadium recovery apparatus has an electrochemical cell structure, a fly ash supply unit 16 to which wet fly ash is supplied, and a diaphragm 17 on one side of the fly ash supply unit 16. And an anode chamber 18 provided on the other side of the fly ash supply unit 16 via a diaphragm 19. As the diaphragms 17 and 19, for example, a microporous membrane such as an MF membrane or an ion exchange membrane can be used.

  The anode chamber 18 is filled with an anode 21 made of a conductive filler, and the cathode chamber 20 is filled with a cathode 22 made of a conductive filler. As these conductive fillers, for example, carbon fiber felt or carbon particles can be preferably used.

  Here, an anode energization member 23 is provided adjacent to the anode chamber 18. The anode energization member 23 can be formed of a conductive member such as glassy carbon. The anode energization member 23 is in contact with the anode 21 in the anode chamber 18 and can be used to energize the anode 21. Similarly, a cathode energization member 24 is provided adjacent to the cathode chamber 20. The cathode energizing member 24 can also be made of a conductive member such as glassy carbon. The cathode energization member 24 is in contact with the cathode 22 in the cathode chamber 20 and can be used to energize the cathode 22.

  The gaps corresponding to the fly ash supply unit 16, the anode chamber 18, and the cathode chamber 20 are secured by spacers 25 arranged between the anode energization member 23 and the cathode energization member 24. In this embodiment, an elastic material such as rubber can be preferably used for the spacer 25, and ethylene-propylene-diene rubber (EPDM) or the like can be preferably used.

  In the vanadium recovery apparatus having the above configuration, the fly ash supply unit 16 is filled with wet fly ash, energized to the anode 21 and the cathode 22, and a voltage is applied between the anode 21 and the cathode 22. Form. In this aspect, in this state, the fly ash in the fly ash supply unit 16 is pressurized.

  Here, by pressing the energizing member 23 for the anode and the energizing member 24 for the cathode from both sides of the cell in the direction of the arrow, the spacer 25 forming the gap corresponding to the fly ash supply unit 16 is compressed and deformed, The fly ash in the fly ash supply unit 16 is pressurized.

  By pressurization under a potential gradient, water in the fly ash is separated into the anode chamber 18 and the cathode chamber 20 through the diaphragm 17 and the diaphragm 19, respectively, and the vanadate ions having a negative charge are separated from the anode 21 and the anode 21, respectively. It is attracted to the anode 21 by the potential gradient with the cathode 22, passes through the diaphragm 17, and moves into the anode chamber 18. As a result, a recovery liquid containing water dehydrated from the wet fly ash and vanadium separated from the fly ash is generated in the anode chamber 18. That is, the recovered liquid can be generated as a desorbed liquid from wet fly ash. The desorbed liquid generated in the anode chamber 18 can be recovered from the desorbed liquid outlet 25a, and the desorbed liquid generated in the cathode chamber 20 can be recovered from the desorbed liquid outlet 25b.

  In this embodiment, the pressure when pressurizing the fly ash is preferably in the range of 0.1 MPa to 1.0 MPa, and more preferably in the range of 0.2 MPa to 0.4 MPa.

  Also in the second aspect of the separation step 2, the total salt concentration in the recovered liquid can be kept very small by separating vanadium by pressurizing wet fly ash under a potential gradient. Therefore, the effect that the concentration by the membrane separation method in the concentration step 3 can be increased is obtained.

  Moreover, in this aspect, the fly ash after vanadium is isolate | separated can be made into the fully dehydrated state. The dehydrated fly ash also provides an effect of excellent handling properties when used as an industrial product such as a concrete admixture.

  In the first aspect and the second aspect of the separation step 2 described above, the case where vanadium is separated from a wet fly ash under a potential gradient is shown, but the present invention is not limited to this. As a third embodiment of the separation step 2, vanadium can be separated by pressurizing wet fly ash. Since vanadium is dissolved in water in wet fly ash, the desorbed liquid generated by pressurizing the fly ash can be used as a recovery liquid containing vanadium. In the third aspect of the separation step 2, for example, the vanadium recovery apparatus shown in FIG. 3 can be used without forming a potential gradient (energization).

  Vanadium recovered by the vanadium recovery processing method of the present invention can be suitably used particularly as an active material of a redox battery.

  In one embodiment, as described above, the vanadium concentrate obtained in the concentration step 3 can be used as an active material liquid for a redox battery. In this case, the vanadium concentrate may be used as the negative electrode active material liquid or may be used as the positive electrode active material liquid. It is particularly preferable to adjust the valence of the vanadium concentrate and use it together as the negative electrode active material liquid and the positive electrode active material liquid.

  In another embodiment, vanadium separated from the vanadium concentrate can be used as an active material for a redox battery.

  As a specific example of a redox battery using vanadium as an active material, a vanadium redox flow battery using vanadium as a bipolar active material can be particularly preferably exemplified. Moreover, a redox battery is not limited to this, What is necessary is just to use vanadium for one active material of a positive electrode and a negative electrode. For example, the present invention can be preferably applied to a vanadium-air (oxygen) battery using air (oxygen) as a positive electrode active material and vanadium as a negative electrode active material.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

Example 1
In Example 1, vanadium is recovered from the fly ash by placing the wet fly ash containing vanadium under a potential gradient. Specifically, the following operations were performed.

(1) Hydrolysis step First, wet fly ash (water content is 45% by weight) is obtained by adding water (pH 7.5) containing 2 g / L of calcium sulfate to fly ash recovered from a heavy oil fired boiler. It was.

(2) Separation Step Next, using the same vanadium recovery apparatus as shown in FIG. 2, the cathode chamber 15 was filled with wet fly ash, and the anode chamber 14 was recovered with a recovered solution (4.5 M-H ₂ SO ₄ aqueous solution). ), A voltage was applied to the anode 11 and the cathode 12 to form a potential gradient of 350 V / m. The processing time was 30 minutes.

  The vanadium concentration of the recovered liquid before recovering vanadium and the recovered liquid after recovering vanadium was determined by measuring the reduction wave height of pentavalent vanadium by CV measurement (cyclic voltammetry) in a 2M sulfuric acid acidic solution.

  The pentavalent vanadium ion concentration in the obtained recovered liquid was 25 mM.

(3) Concentration step The recovered solution after recovering vanadium was concentrated by a reverse osmosis membrane method using a flat membrane type reverse osmosis membrane device to obtain a vanadium concentrate. The pentavalent vanadium ion concentration in the obtained concentrated liquid was 2.3M.

(Example 2)
In Example 2, vanadium is recovered from the fly ash by pressurizing wet fly ash containing vanadium under a potential gradient. Specifically, the following operations were performed.

(1) Water addition step As in Example 1, water was added to fly ash recovered from a heavy oil fired boiler to obtain wet fly ash.

(2) Separation Step Next, using the same vanadium recovery apparatus as shown in FIG. 3, the fly ash supply unit 16 is filled with wet fly ash, and a voltage is applied to the anode 21 and the cathode 22 to obtain 350 V / In a state where a potential gradient of m was formed, fly ash wetted by pressing the cell from both sides was pressurized at a pressure of 0.5 Mpa. The processing time was 30 minutes.

  The pentavalent vanadium ion concentration in the obtained recovered liquid was 30 mM.

(3) Concentration step The recovered liquid after recovering vanadium was concentrated under the same conditions as in Example 1 to obtain a vanadium concentrated liquid. The pentavalent vanadium ion concentration in the obtained concentrated liquid was 2.5M.

(Example 3)
In Example 3, vanadium is recovered from the fly ash by pressurizing wet fly ash containing vanadium. Specifically, the following operations were performed.

(1) Water addition step As in Example 1, water was added to fly ash recovered from a heavy oil fired boiler to obtain wet fly ash.

(2) Separation Step Next, using the same vanadium recovery device as shown in FIG. 3, the fly ash supply unit 16 is filled with wet fly ash, and no voltage is applied to the anode 21 and the cathode 22, and the potential gradient In a state in which the cell was not formed, the fly ash wetted by pressing the cell from both sides was pressurized at a pressure of 0.5 Mpa. The processing time was 30 minutes. The pentavalent vanadium ion concentration in the obtained recovered liquid was 25 mM.

(3) Concentration step The recovered liquid after recovering vanadium was concentrated under the same conditions as in Example 1 to obtain a vanadium concentrated liquid. The pentavalent vanadium ion concentration in the obtained concentrated liquid was 1.8M.

(Reference Example 1)
In Reference Example 1, the wet fly ash containing vanadium was omitted from being placed under a potential gradient, and was pressurized with a small pressure (about 0.01 MPa) less than 1.0 MPa. Specifically, the following operations were performed.

(1) Water addition step As in Example 1, water was added to fly ash recovered from a heavy oil fired boiler to obtain wet fly ash.

2. Separation Step Next, using the same vanadium recovery device as shown in FIG. 3, the fly ash supply unit 16 is filled with wet fly ash, no voltage is applied to the anode 21 and the cathode 22, and no potential gradient is formed. In this state, the fly ash was pressurized at a pressure of about 0.01 MPa. The treatment time was 45 minutes.

  The pentavalent vanadium ion concentration in the obtained recovered liquid was 3 mM. In Reference Example 1, the concentration step was omitted.

  The results are shown in Table 1.

<Evaluation>
From Table 1, in the separation step, wet fly ash is placed under a potential gradient (Example 1), pressurized in the range of 0.1 MPa to 1.0 MPa (Example 3), or 0. 0 under a potential gradient. It can be seen that vanadium can be efficiently recovered by pressurizing in the range of 1 MPa to 1.0 MPa (Example 2).

  Furthermore, in Examples 1 to 3, the approximate osmotic pressure of the recovered liquid (concentrated liquid) to be concentrated was only about 0.1 MPa, and the concentration could be about 100 times. That is, since the total salt concentration of the recovered liquid is kept very low, it can be seen that the degree of concentration can be increased by a membrane separation method such as a reverse osmosis membrane method.

  It was confirmed that substantially all vanadium was present as pentavalent vanadium ions in the recovered solution and the concentrated solution. Therefore, the pentavalent vanadium ion concentration substantially corresponds to the total vanadium ion concentration.

1: Hydrolysis step 2: Separation step 3: Concentration step 4: Adjustment step 11: Anode 12: Cathode 13: Membrane 14: Anode chamber 15: Cathode chamber 16: Fly ash supply unit 17: Membrane 18: Anode chamber 19: Membrane 20 : Cathode chamber 21: Anode 22: Cathode 23: Current-carrying member for anode 24: Current-carrying member for cathode 25: Spacer

Claims (5)

Vanadium is recovered using a vanadium recovery device in which a diaphragm (13) is disposed between an anode chamber (14) provided with an anode (11) and a cathode chamber (15) provided with a cathode (12). When
Supplying the cathode chamber (15) with fly ash wetted by water with high-oxidized vanadium and water containing alkali;
In a state where an aqueous solution containing an electrolyte for recovering the vanadium is supplied to the anode chamber (14), a potential is applied to the anode (11) and the cathode (12) by applying a potential, A vanadium recovery treatment method characterized in that vanadate ions having negative charges in fly ash are passed through the diaphragm (13) and recovered in the aqueous solution in the anode chamber (14) to obtain a vanadium recovery solution. .   The vanadium recovery processing method according to claim 1, wherein the wet fly ash is pressurized in a range of 0.1 MPa to 1.0 MPa under a potential gradient.   The vanadium recovery processing method according to claim 1, wherein the diaphragm is a microporous membrane.   The vanadium recovery processing method according to claim 1, 2 or 3, wherein the vanadium recovery liquid containing vanadate ions recovered in the aqueous solution in the anode chamber (14) is concentrated by a reverse osmosis membrane method. Use of vanadium, characterized in that vanadium recovered by the vanadium recovery processing method according to any one of claims 1 to 4 is used as an active material of a redox battery.

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