JP3401871B2 - Waste liquid regeneration processing method and apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste liquid regeneration treatment method and apparatus for removing impurity metal ions from a waste liquid to regenerate the liquid.

[0002]

2. Description of the Related Art As a method for removing impurity metal ions from waste liquid to regenerate the liquid, for example, Japanese Patent Publication No. 57-614.
There is a method for treating recycled waste liquid disclosed in No. 77. FIG. 5 is an explanatory view showing the principle of the method for treating the waste liquid for regeneration described above. The anode chamber 5 is filled with a regeneration waste liquid 9 containing sodium ions (Na ⁺ ) to immerse the anode plate 11, and the cathode chamber 7 is filled with a caustic soda (NaOH) solution 13 to immerse the cathode plate 15. A direct current voltage is applied between the anode plate 11 and the cathode plate 15 by the power source 17 to flow a current. This allows
In the caustic soda solution 13 in the cathode chamber 7, hydrogen ions (H ⁺ ) are generated by the decomposition reaction of water to form hydroxide ions (OH ⁻ ), while the sodium ions in the regeneration waste liquid 9 in the anode chamber 5 are It moves to the cathode chamber 7 through the cation exchange membrane 3, reacts with the hydroxide ions in the cathode chamber 7 and is recovered as caustic soda, and the sodium ions in the regeneration waste liquid 9 in the anode chamber 5 are removed to regenerate the liquid.

Therefore, a waste liquid containing metal ions is put in the anode chamber 5 instead of the regeneration waste liquid 9, and an aqueous solution of a strong acid such as sulfuric acid (H ₂ SO ₄ ) is put in the cathode chamber 7 instead of the caustic soda solution 13. By putting in and energizing between the anode plate 11 and the cathode plate 15 by the DC power supply 17, the metal ions in the waste liquid can be collected in the cathode chamber 7 through the cation exchange membrane 3 and the aqueous acid solution can be regenerated.

Examples of the waste liquid which is regenerated by the above-mentioned regenerating method include an aqueous solution of an acid used in the surface treatment after the blackening treatment of the multilayer printed circuit board. In the process of manufacturing a multilayer printed circuit board, for the copper foil to be the inner layer wiring in order to enhance the adhesion with the adhesive layer when laminating the board materials and to improve the resistance in the plating solution in the subsequent plating process. A treatment called blackening treatment may be performed, and surface treatment with acid may be further performed.

The blackening treatment means that copper oxide (C) is formed on the surface of a copper foil to be an inner layer wiring by using an alkaline oxidation treatment liquid.
u ₂ O or CuO) and the like, and refers to a roughening treatment for producing irregularities on the surface of the copper foil by the acicular crystals, and the alkaline oxidation treatment liquid is alkaline chlorite. A sodium aqueous solution or the like is used. Further, the surface treatment with the acid means a treatment for dissolving and removing needle-like crystals from the surface of the copper foil after the blackening treatment, and for roughening the surface more finely. (CH
₃ COOH), citric acid (C (CH ₂ COOH) ₂ (O
An aqueous solution of H) COOH), tartaric acid (C ₄ H ₆ O ₄ ), fumaric acid or the like can be used. For example, when an aqueous solution of acetic acid is used for the surface treatment, the reaction when acetic acid dissolves copper oxide is 2CH ₃ COOH + CuO → (CH ₃ COO) ₂
+ H ₂ O, and the reaction when citric acid is used becomes as shown in [Chemical formula 1]. After surface treatment, an aqueous solution of acetic acid or citric acid is added to the copper ion (eg Cu ²⁺ ) in copper oxide.
Melts into waste liquid.

[0006]

[Chemical 1]

Since an aqueous solution of acetic acid or citric acid has little fluctuation in pH when dissolving copper oxide, it is necessary to use an aqueous solution of acetic acid or citric acid for the above-mentioned surface treatment for stable treatment. preferable.

However, in an aqueous solution of acetic acid or citric acid,
Only about 2 grams of copper can be dissolved per liter, and the amount of copper that can dissolve an acid is generally limited. Therefore, when dissolving a large amount of copper oxide as in a printed circuit board manufacturing line, a waste liquid is used. It needs to be replaced frequently with a fresh aqueous solution of acid, which is very troublesome. Further, in order to frequently replace the waste liquid with a new acid aqueous solution, a large amount of the acid aqueous solution is required, and the cost of the liquid is high. Therefore, in the production process line of a printed circuit board, it is desired to remove copper ions from waste liquid to regenerate an acid aqueous solution and reuse it for surface treatment. From such a background, in removing metal ions from the waste liquid and regenerating it, an important issue is how to efficiently regenerate a large amount of waste liquid.

[0009]

However, when the waste liquid containing the metal ions is regenerated by utilizing the method for treating the waste liquid for regeneration shown in FIG. 5, the metal ions in the waste liquid, such as the copper ions described above, are treated. When the ionization tendency of is smaller than that of hydrogen ions, the metal ions come into contact with the cathode plate 15 and combine therewith, and metal is deposited and adheres around the cathode plate 15, so that the cathode plate 15 needs to be replaced, and a large amount is generated. However, there is a problem in that the efficiency becomes poor when the waste liquid is treated. In addition, when an organic acid waste liquid such as acetic acid or citric acid as described above is put into the anode chamber 5, the components of the organic acid are consumed by the anode plate 11 immersed in the waste liquid, and the electrode reaction (oxidation reaction). ) Is generated, which causes a problem that the aqueous acid solution regenerated in the anode chamber 5 is altered.
The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to efficiently remove metal ions from a waste liquid containing metal ions, and also to prevent deterioration of the regenerated liquid. It is to provide a processing method and an apparatus thereof.

[0010]

The present invention according to any one of claims 1 to 4 is a method for regenerating a waste liquid containing a metal ion, and the present invention according to any one of claims 5 to 12 provides: It relates to the device. The present invention according to claim 1 is
A third chamber in which an aqueous solution of acid is stored in the first chamber, the waste liquid is stored in a second chamber connected to the first chamber, and an aqueous solution of acid is stored in the third chamber.
A chamber and a fourth chamber are connected to the second chamber, and an anode to which a DC voltage is applied is brought into contact with the acid aqueous solution in the first chamber, and a DC voltage is applied to the acid aqueous solution in the fourth chamber. The cathode is brought into contact with the cathode, hydrogen ions in the first chamber are guided to the second chamber, and the metal ions are discharged from the second chamber to the third chamber.

The present invention according to claim 2 uses a strong acid as the acid. According to the present invention of claim 3, sulfuric acid or hydrochloric acid is used as the strong acid. Claim 4
The present invention as described above, wherein the aqueous solution of the acid in the fourth chamber and the first
The aqueous solution of the chamber was kept at the same concentration and quality.

According to a fifth aspect of the present invention, there is provided a first chamber containing an aqueous solution of an acid and a first chamber containing a waste liquid containing metal ions and connected to the first chamber via a cation exchange membrane. 2 chambers, a third chamber containing an aqueous acid solution and connected to the second chamber via a cation exchange membrane, and a third chamber containing an aqueous acid solution to the third chamber via an anion exchange membrane. A fourth chamber provided, an anode disposed in the first chamber in contact with the acid aqueous solution, a cathode disposed in the fourth chamber in contact with the acid aqueous solution, and the anode And a power supply for applying a DC voltage between the cathodes.

According to a sixth aspect of the present invention, waste liquid supply means for supplying the waste liquid to the second chamber, and regeneration for discharging the regenerant liquid in the second chamber from which the metal ions have been removed to the outside of the second chamber. A liquid discharging means is further provided. In the present invention according to claim 7, a partition plate is arranged in the second chamber, and a flow path is formed in the second chamber by the partition plate. In the present invention according to claim 8, a partition plate is provided in the third chamber, a flow path is formed in the third chamber by the partition plate, and a flow direction of the aqueous acid solution in the second chamber and the third chamber are defined. The directions in which the aqueous solution of acid in the chamber flows were opposite to each other. The present invention according to claim 9 provides the first chamber and the fourth chamber.
Partition plates are respectively arranged in the chambers, and the partition plates form flow paths in the first chamber and the fourth chamber, respectively. The flow direction of the aqueous acid solution in the first chamber and the aqueous solution of the acid in the second chamber are The flowing direction is opposite to each other, and the flowing direction of the aqueous acid solution in the third chamber is opposite to the flowing direction of the aqueous acid solution in the fourth chamber.

According to a tenth aspect of the present invention, there is further provided recirculation means for recirculating the acid aqueous solution in the first chamber and the fourth chamber between both chambers. The present invention according to claim 11 provides
The recirculation unit includes a reserve tank in which a part of the aqueous acid solution that is recirculated between the first chamber and the fourth chamber is stored, and a concentration measuring unit that measures the concentration of the acid in the reserve tank. It has been configured. The present invention according to claim 12 is characterized in that a plurality of treatment tanks each including the first chamber, the second chamber, the third chamber, and the fourth chamber are continuously provided, and the fourth chamber and the other of the adjacent one treatment tank are provided. Shared with the first chamber of the processing tank, the anode is provided only in the first chamber located at one end of the continuously connected processing tanks, and the other end of the continuously connected processing tanks is disposed. The cathode is arranged only in the fourth chamber located in the.

[0015]

According to the present invention, the hydrogen ions in the first chamber are guided to the second chamber, and the metal ions are discharged from the second chamber to the third chamber, so that the metal ions are discharged from the waste liquid in the second chamber. The removed liquid is regenerated and the anode to which the DC voltage is applied does not come into contact with the waste liquid, so that the liquid regenerated in the second chamber does not cause an electrode reaction, and the cathode to which the DC voltage is applied. Does not come into contact with the acid aqueous solution in the third chamber, even if the metal ions removed from the waste liquid and recovered have a smaller ionization tendency than hydrogen ions, the metal ions touch the cathode and bond with it. No metal deposits and adheres around the cathode. Therefore, it is possible to efficiently remove the metal ions from the waste liquid containing the metal ions to regenerate the waste liquid, and to prevent alteration of the regenerated liquid.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing a schematic configuration of a waste liquid recycling apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 21 denotes a treatment tank. Inside the treatment tank 21, two cation exchange membranes 23 and one anion exchange membrane 2 are arranged in this order from the left in the figure.
5 are provided, and these ion exchange membranes 23, 23, 25
Thus, the inside of the processing tank 21 is partitioned into four first to fourth chambers 27, 29, 31, 33 in order from the left in the figure. Here, the cation exchange membrane 23 and the anion exchange membrane 2
It is preferable to use an acid-resistant material for 5, and specifically, as the cation exchange membrane 23, a product name “Selemion CMV” manufactured by Asahi Glass Co., Ltd. can be used, and as the anion exchange membrane 25, manufactured by the same company. The brand name of "Selemion AMV" can be used.

Supply pipes 35 are connected to the bottom side portions of the first chamber 27 and the fourth chamber 33, respectively, and recovery pipes 37 are connected to the upper side portions thereof, and the supply pipes 35 and the recovery pipes 37 are respectively connected. It is led to the reserve tank 39. First chamber 27, fourth chamber 33, and reserve tank 39
An aqueous solution 41 of sulfuric acid is put in the container, and the aqueous solution 41 of sulfuric acid is passed between the reserve tank 39 and the first chamber 27 through the supply pipe 35 and the recovery pipe 37, and between the reserve tank 39 and the fourth chamber. 33, so that the aqueous solutions 41 of sulfuric acid in the first chamber 27, the fourth chamber 33, and the reserve tank 39 are always maintained at the same concentration.
A valve 43 and a pump 45 for adjusting the flow rate are respectively provided in the supply pipe 35 and the recovery pipe 37, and a concentration measuring device 49 for monitoring the concentration of the sulfuric acid aqueous solution 41 therein is provided in the reserve tank 39. It is arranged. In the present embodiment, the supply pipe 35, the recovery pipe 37, the reserve tank 39, the valve 43, the pump 45, and the concentration measuring device 49 constitute recirculation means.

Further, an anode plate 51 is provided in the first chamber 27 by partially immersing it in the sulfuric acid aqueous solution 41, and a cathode plate 53 is provided in the fourth chamber 33 by partially immersing it in the sulfuric acid aqueous solution 41. A DC voltage from a DC power supply 55 is applied between the anode plate 51 and the cathode plate 53. The anode plate 51
It is desirable to use an insoluble material for the cathode plate 53 so that the cathode plate 53 does not dissolve in the aqueous solution 41 of sulfuric acid in the first chamber 27 and the fourth chamber 33, and in this embodiment, the anode plate 51 is used. A plate material in which titanium (Ti) is coated with platinum (Pt) is used, and a copper plate is used as the cathode plate 53. The anode plate 51 is not limited to a plate material in which titanium is coated with platinum, but other plate materials can be used, and preferably platinum, nickel (Ni), a commercially available carbon electrode, or the like can be used. Similarly, the cathode plate 53 is not limited to a copper plate, but another plate material can be used, and preferably a nickel or titanium plate material can be used.

A supply pipe 57 is provided at the upper opening of the second chamber 29.
Is provided, and the supply pipe 57 is connected to the waste liquid tank 59. A recovery pipe 61 is connected to the bottom of the second chamber 29, and the recovery pipe 61 is guided to the regenerant tank 63. The waste liquid tank 59 contains a copper acetate aqueous solution 65 corresponding to the waste liquid.
Is supplied to the second chamber 29 through the supply pipe 57.
The aqueous solution 65 of copper acetate in the second chamber 29 has copper ions removed by a regeneration treatment described later to be regenerated into a liquid close to the aqueous solution of acetic acid, and the regenerated liquid is recovered from the second chamber 29 to the recovery pipe 61. It is recovered in the regenerant tank 63 through the above. A valve 6 for adjusting the flow rate is provided in the supply pipe 57 and the recovery pipe 61.
7 are provided respectively. In the present embodiment, the supply pipe 57, the waste liquid tank 59, and the valve 67 constitute a waste liquid supply means, and the recovery pipe 61, the regenerant liquid tank 63, and the valve 67 constitute a regenerated liquid discharge means. There is.

A supply pipe 69 is arranged in the upper opening of the third chamber 31, and the supply pipe 69 is connected to a liquid tank 71. A recovery pipe 73 is provided at the bottom of the third chamber 31.
Is connected, and the recovery pipe 73 is guided to a liquid tank 74 for recovering copper ions. An aqueous solution 41 of sulfuric acid having the same concentration as that of the reserve tank 39 is placed in the liquid tank 71, and the aqueous solution 41 of sulfuric acid is supplied to the third chamber 31 via the supply pipe 69. In the third chamber 31, copper ions in the aqueous solution 65 of copper acetate are recovered by the regeneration treatment described later, and the third chamber 3 containing the recovered copper ions.
The sulfuric acid aqueous solution 41 of No. 1 is recovered in the liquid tank 74 through the recovery pipe 73. The supply pipe 69 and the recovery pipe 7
3 are provided with valves 75 for adjusting the flow rate.

Further, the first chamber 27, the third chamber 31, the fourth chamber
In the chamber 33, the reserve tank 39, and the liquid tank 71,
Although an acid aqueous solution other than the sulfuric acid aqueous solution 41 may be added, a strong acid aqueous solution is preferable. From the viewpoint of cost and handling, it is desirable to use the sulfuric acid aqueous solution 41 or the hydrochloric acid aqueous solution, and in particular, It is desirable to use a liquid in consideration of suitability for the cation exchange membrane 23 and the anion exchange membrane 25. Further, the first chamber 27, the third chamber 31, the fourth chamber 3
3, it is desirable that the liquids in the reserve tank 39 and the liquid tank 71 have such a concentration and quality that the electric resistance thereof is about the same as that of the copper acetate solution 65 in the second chamber 29. Also,
The first chamber 27, the fourth chamber 33, and the reserve tank 39
The liquid and the liquid in the third chamber 31 and the liquid tank 71 may have different concentrations and qualities, but from the viewpoint of facilitating the management of the liquid and the first chamber 27. , The third chamber 31, and the fourth chamber 33, it is desirable that the concentration and quality are the same in order to prevent the voltage applied to the liquid in each chamber from fluctuating.

Next, the regenerating processing operation by the waste liquid regenerating apparatus having the above-mentioned structure will be described. First, an aqueous solution 41 of sulfuric acid is placed in the first chamber 27, the third chamber 31, and the fourth chamber 33.
While filling the second chamber 29 with an aqueous solution of copper acetate 65
Meet Next, the pump 45 is operated and the valves 43, 67, 75 are opened, and the aqueous solution 41 of sulfuric acid is made to flow from the bottom part to the upper part in the first chamber 27 and the third chamber 31, respectively, and the second chamber 29 is made to flow. In the fourth chamber, the aqueous solution 65 of copper acetate and the aqueous solution 41 of sulfuric acid are made to flow from the top to the bottom. Then, a DC voltage is applied between the anode plate 51 and the cathode plate 53 by the DC power supply 55 to start the regeneration processing operation.

First, in the first chamber 27, the sulfuric acid in the aqueous solution 41 of sulfuric acid is converted into hydrogen ions (H ⁺ ) which are cations.
And a sulfate ion (SO ₄ ²⁻ ) which is an anion, and a small amount of water (H ₂ O) is a hydrogen ion (H ⁺ ) which is a cation and water which is an anion. Acid ion (O
H ^-) are ionized into a. Then, when electricity is applied by the DC power source 55, the sulfate ions transfer electrons to the anode plate 51 and at the same time, combine with water to form sulfuric acid and oxygen (O ₂ ), and the oxygen thus formed becomes a bubble and the sulfuric acid aqueous solution 41. From the liquid surface of the first chamber 2
7 Go out. In addition, a small amount of hydroxide ion is generated in the anode plate 5.
At the same time when the electrons are transferred to 1, the water is combined with each other to form water (H ₂ O), and the remaining oxygen (O ₂ ) is bubbled to the outside of the first chamber 27 from the liquid surface of the aqueous solution 41 of sulfuric acid.

That is, in the first chamber, 2H ₂ O → 4e ⁻ +4
Since the reaction of H ⁺ + O ₂ ↑ occurs, hydrogen ions remain in the first chamber 27, and the charge is biased to the positive side. As a result, the action of returning the electric charge that is biased to the positive side to the original state occurs, and the first
Since the chamber 27 is partitioned from the adjacent second chamber 29 by the cation exchange membrane 23, hydrogen ions move from the first chamber 27 through the cation exchange membrane 23 to the second chamber 29. still,
The composition of the aqueous solution 41 of sulfuric acid in the first chamber 27 is the DC power source 55.
Sulfate ion, hydrogen ion,
The water and the trace amount of hydroxide ions remain unchanged, and the concentration of the sulfuric acid aqueous solution 41 hardly changes.

Next, in the second chamber 29, the hydrogen ions move from the first chamber 27, so that the electric charges are biased to the plus side, and the action of restoring the charges is generated. Second room 29
Are partitioned by the first and second chambers 27 and 31 and the cation exchange membrane 23 which are adjacent to each other. Since hydrogen ions move from the first chamber 27 as described above, they are biased to the plus side. The cations in the second chamber 29 move to the third chamber 31 through the cation exchange membrane 23 in order to restore the charge. Here, the composition of the aqueous solution 65 of copper acetate in the second chamber 29 is acetate ion (CH ₃ COO ⁻ ), acetic acid, hydrogen ion, copper ion, and water, of which the cation is copper ion and hydrogen ion. Therefore, from the second chamber 29,
Copper ions and hydrogen ions move to the third chamber 31 through the cation exchange membrane 23. Therefore, the amount of copper ions contained in the aqueous solution 65 of copper acetate in the second chamber 29 gradually becomes small as the copper ions move to the third chamber 31 during energization, and therefore, the amount of copper ions in the second chamber 29 increases. The aqueous solution 65 of copper acetate is regenerated into a solution close to the aqueous solution of acetic acid over time.

Then, in the fourth chamber 33, the sulfuric acid in the aqueous solution 41 of sulfuric acid is converted into hydrogen ions (H ⁺ ) which are cations.
And a sulfate ion (SO ₄ ²⁻ ) which is an anion, and a small amount of water (H ₂ O) is a hydrogen ion (H ⁺ ) which is a cation and water which is an anion. Acid ion (O
H ^-) are ionized into a. When the DC power source 55 is energized, the hydrogen ions receive electrons from the electrons from the cathode plate 53, and at the same time, they combine with each other to form hydrogen (H ₂ ), and become bubbles to form a fourth solution from the surface of the aqueous solution 41 of sulfuric acid. Room 3
3 Go out.

[0027] Therefore, in the fourth chamber 33, 4e ^- + 4H
A reaction of ⁺ → 2H ₂ ↑ occurs, sulfate ions and a small amount of hydroxide ions remain in the fourth chamber 33, and the electric charge is biased to the negative side and the negative biased charge is returned to the original state. Since the fourth chamber 33 is partitioned from the adjacent third chamber 31 by the anion exchange membrane 25, sulfate ions and a small amount of hydroxide ions pass from the fourth chamber 33 through the anion exchange membrane 25. Move to the third chamber 31. Incidentally, the fourth chamber 3
The composition of the aqueous solution 41 of sulfuric acid of No. 3 is sulfate ion, hydrogen ion, water, and a trace amount of hydroxide ion before energization by the DC power source 55, and after energization, the hydrogen ion becomes hydrogen and becomes the fourth chamber. 33 I'm going to go outside,
Change to water and trace amount of hydroxide ion. Also, the fourth chamber 3
The amount of sulfate ion contained in the aqueous solution 41 of sulfuric acid of 3 is
As the sulfate ions move to the third chamber 31 during energization, the amount thereof becomes gradually smaller, and therefore, the aqueous solution 41 of sulfuric acid in the fourth chamber 33 approaches water with the passage of time.

Finally, in the third chamber 31, the second chamber 27
Copper ions and hydrogen ions move from the chamber, and sulfate ions and a small amount of hydroxide ions move from the fourth chamber 33. Since the third chamber 31 is partitioned from the adjacent second chamber 29 by the cation exchange membrane 23, the sulfate ions and the trace amount of hydroxide ions transferred from the fourth chamber 33 are stored in the third chamber 31. It remains in the aqueous solution 41 of sulfuric acid. In addition, the third chamber 31 and the adjacent fourth chamber 33 and the anion exchange membrane 25.
Since it is partitioned by, the copper ions and hydrogen ions that have moved from the fourth chamber 33 also stay in the aqueous solution 41 of sulfuric acid in the third chamber 31, like the sulfate ions and the trace amount of hydroxide ions. Therefore, the composition of the aqueous solution 41 of sulfuric acid in the third chamber 31 is sulfate ion, hydrogen ion, water, and a small amount of hydroxide ion before the energization by the DC power supply 55, whereas after the energization, the sulfate ion, It changes into copper ions, hydrogen ions, water, and a trace amount of hydroxide ions, and the aqueous solution 41 of sulfuric acid in the third chamber 31 approaches the aqueous solution of sulfuric acid + copper sulfate over time.

As described above, the aqueous solution 65 of copper acetate in the second chamber 29 is regenerated into a liquid close to the aqueous solution of acetic acid, and the liquid close to the regenerated aqueous solution of acetic acid is collected in the recovery pipe 61.
Then, it is recovered from the second chamber 29 into the regenerant tank 63. The copper ions removed from the copper acetate aqueous solution 65 in the second chamber 29 move into the sulfuric acid aqueous solution 41 in the third chamber 31, and the sulfuric acid aqueous solution 41 containing the copper ions is collected in the recovery pipe 73. After that, the liquid is collected from the third chamber 31 to the liquid tank 74.

As described above, in this embodiment, the cathode plate 55 is not soaked in the aqueous solution 41 of sulfuric acid placed in the third chamber 31 in which the copper ions are collected, so that the copper ions are deposited on the cathode plate 55. Since it does not deposit and adhere, it is not necessary to replace the cathode plate 55, and a large amount of waste liquid can be efficiently treated. That is, in this embodiment, even if the waste liquid contains metal ions such as copper ions having a smaller ionization tendency than hydrogen ions, the metal is prevented from depositing and adhering to the cathode plate 55, and the regeneration treatment is efficiently performed. be able to.

Further, in this embodiment, since the anode plate 53 is not immersed in the copper acetate solution 65 contained in the second chamber 29, the copper acetate solution 65 does not touch the anode plate 53. Therefore, it is possible to prevent the organic acid component in copper acetate from being consumed to cause an electrode reaction (oxidation reaction), and to prevent the liquid near the aqueous solution of acetic acid regenerated in the second chamber 29 from being deteriorated. Further, in this embodiment, the second chamber 29 is connected to the waste liquid tank 59 via the supply pipe 57, and the second chamber 29 is connected to the regenerating liquid tank 63 via the recovery pipe 61 to form the waste liquid tank. Since the aqueous solution 65 of copper acetate is supplied from 59 to the second chamber and the solution close to the aqueous solution of acetic acid regenerated in the second chamber 29 is collected in the regenerant tank 63, the aqueous solution 65 of copper acetate is The regeneration treatment can be continuously performed in the second chamber 29, and the regeneration from the copper acetate aqueous solution 65 to the acetic acid aqueous solution can be performed with high efficiency.

In the waste liquid recycling apparatus of the present embodiment, as the aqueous solution 41 of sulfuric acid in the fourth chamber 33 approaches water with the passage of time, the fourth chamber 33 and the fourth tank 33 pass through the reserve tank 39 to reach a fourth position. The first chamber 27 communicating with the chamber 33
The concentration of the aqueous solution 41 of sulfuric acid decreases. Therefore, the concentration measuring device 49 monitors the concentration of the aqueous solution 41 of sulfuric acid in the reserve tank 39, and if necessary, the reserve tank 39.
It is desirable to supply sulfuric acid to the first chamber 27, the fourth chamber 33, and the reserve tank 39 to maintain the concentration of the aqueous solution 41 of sulfuric acid at the initial concentration.

The waste liquid recycling method and apparatus of the present invention are not limited to the configurations shown in the embodiments. For example,
In the first to fourth chambers 27, 29, 31, 33, FIG.
If partition plates 77 as shown in (a) and (b) are provided in the same manner in each chamber in a direction perpendicular to the cation exchange membrane 23 and the anion exchange membrane 25, the first to fourth Room 2
Since the flow path of the liquid flowing through 7, 29, 31, and 33 is determined, it is advantageous in increasing the efficiency in regenerating the liquid near the acetic acid aqueous solution from the copper acetate aqueous solution 65.

Further, for example, as shown in FIG. 3, with respect to the third chamber 31, the supply pipe 69 is connected to the bottom of the third chamber 31, and the recovery pipe 73 is connected to the upper liquid surface portion of the third chamber 31. With respect to the fourth chamber 33, the recovery pipe 37 is connected to the bottom of the fourth chamber 33, and the supply pipe 35 is provided in the upper opening of the fourth chamber 33. It is also advantageous to increase the regeneration efficiency by making the flowing directions of the liquid upside down.

According to this structure, a large amount of copper ions immediately before being recovered from the second chamber 29 to the regenerant tank 63 are contained in the bottom side portions of the second chamber 29 and the third chamber 31, for example. The aqueous solution 65 of copper acetate comes into contact with the aqueous solution 41 of sulfuric acid just supplied from the liquid tank 71 to the third chamber 31 via the supply pipe 69 via the cation exchange membrane 23. Therefore, at the bottom side portions of the second chamber 29 and the third chamber 31, copper ions are roughly contained in the aqueous solution 41 of sulfuric acid in the third chamber 31.
Thus, the efficiency of regenerating the aqueous solution of acetic acid in the second chamber 29 can be improved.

Further, a plurality of the treatment tanks 21 may be arranged so that a large amount of waste liquid can be treated. In that case, the partition between the fourth chamber 33 and the first chamber 27 of the adjacent treatment tanks 21 is eliminated. The first chamber 27, the second chamber 29, the third chamber 31, the fourth chamber 33 (combined with the first chamber), the second chamber, and the second chamber are communicated in order from the left in the drawing, for example, as in the processing tank unit 21A shown in FIG. The chambers 29, the third chamber 31, the fourth chamber 33 (also serving as the first chamber), the second chamber 29, the third chamber 31, and the fourth chamber 33 may be defined as each chamber. By doing so, a part of the first chamber 27 can also be used as the fourth chamber 33, so that the scale of the tank can be reduced, and moreover, the number of supply / recovery paths of the aqueous solution 41 of sulfuric acid and the amount of use of the aqueous solution 41 of sulfuric acid are used. Can be reduced.

Furthermore, in the present embodiment, the case where the metal ions contained in the waste liquid are copper ions has been described. However, the method and apparatus of the present invention are widely used for recycling waste liquids containing other metal ions. It is needless to say that it is applicable, and it is particularly suitable for use in the regeneration treatment of a waste liquid containing metal ions having a smaller ionization tendency than hydrogen ions.

[0038]

As described above, according to the present invention, there is provided a method for regenerating a waste liquid containing metal ions, in which an aqueous solution of an acid is contained in the first chamber and is continuously connected to the first chamber. The second chamber contains the waste liquid, the third chamber and the fourth chamber containing the acid aqueous solution are connected to the second chamber, and an anode to which a direct current voltage is applied to the acid aqueous solution in the first chamber is installed. While bringing them into contact with each other, a cathode to which a DC voltage is applied is brought into contact with the aqueous solution of the acid in the fourth chamber, the hydrogen ions in the first chamber are guided to the second chamber, and the metal ions are transferred from the second chamber to the third chamber. Since it is made to be discharged to, it is possible to prevent the metal from depositing on the cathode and efficiently remove the metal ions from the waste liquid containing the metal ions.
It is possible to prevent alteration of the regenerated liquid.

Hereinafter, the effects of the present invention will be described more specifically with reference to experimental examples, but the present invention is not construed as being limited to the following experimental examples. [Experimental Example] 0.02 A / dm in the aqueous solution 65 of copper acetate
^The DC power supply 55 so that the current flows at the current density of ²
DC voltage is applied between the anode plate 51 and the cathode plate 53 by means of the cation exchange membrane 23 and the anion exchange membrane 25.
In the first to fourth chambers 2 so that 0.05 liter of liquid per hour per 1 dm ² of membrane area can pass therethrough.
The flow rates of the respective liquids at 7, 29, 31, and 33 are set by the valve 4
It was controlled by adjusting the opening of 3,67,75.

Then, the copper ions contained in the copper acetate aqueous solution 65 before the regeneration treatment and the second ion after the regeneration treatment are carried out.
Comparing the amount of copper ions contained in the liquid close to the aqueous solution of acetic acid recovered from the chamber 29 into the regeneration liquid tank 63, 95% of the copper ions before the regeneration process were removed after the regeneration process. Was confirmed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a waste liquid recycling apparatus according to an embodiment of the present invention.

FIG. 2 relates to a modified example of the present invention and is shown in FIGS.
FIG. 3 is an explanatory diagram showing a state where partition plates are provided in the first to fourth chambers in FIG. 1.

FIG. 3 is an explanatory diagram according to another modification of the present invention, in a case where the adjacent chambers in the processing tank are configured so that the flowing directions of liquids are upside down.

FIG. 4 is a schematic configuration diagram of a processing tank unit in which a plurality of processing tanks shown in FIG. 1 are arranged according to another modification of the present invention.

FIG. 5 is an explanatory diagram showing the principle of a conventional method for treating a recycled waste liquid that can be used to regenerate an aqueous acid solution from a waste liquid containing copper ions.

[Explanation of symbols]

21 Processing tank 23 Cation exchange membrane 25 Anion exchange membrane 27 Room 1 29 Room 2 31 Room 3 33 Room 4 35 supply pipe (circulating means) 37 Recovery pipe (circulation means) 39 Reserve tank (circulation means) 41 Sulfuric acid aqueous solution (acid aqueous solution) 43 valve (circulation means) 45 Pump (circulation means) 47 Concentration measuring device (reflux means, concentration measuring means) 51 Anode plate 53 cathode plate 55 DC power supply 57 Supply pipe (waste liquid supply means) 59 Waste liquid tank (waste liquid supply means) 61 Recovery pipe (regeneration liquid discharge means) 63 Regenerated liquid tank (regenerated liquid discharge means) 65 Copper acetate aqueous solution (waste liquid) 67 valve (waste liquid supply means, regeneration liquid discharge means) 77 Partition board

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Claims (12)

(57) [Claims] 1. A method for regenerating a waste liquid containing metal ions, wherein an aqueous solution of an acid is stored in a first chamber, and the waste liquid is stored in a second chamber connected to the first chamber, The third and fourth chambers containing the aqueous solution of No. 3 are connected to the second chamber, and the aqueous solution of the acid in the first chamber is brought into contact with the anode to which a DC voltage is applied, and A cathode to which a direct current voltage is applied is brought into contact with the aqueous solution, hydrogen ions in the first chamber are guided to the second chamber, and the metal ions are discharged from the second chamber to the third chamber. Waste liquid recycling method. 2. The waste liquid regeneration treatment method according to claim 1, wherein a strong acid is used as the acid. 3. The waste liquid regeneration treatment method according to claim 2, wherein sulfuric acid or hydrochloric acid is used as the strong acid. 4. The acid solution in the fourth chamber and the acid solution in the first chamber are maintained at the same concentration and at the same quality. Waste liquid recycling method. 5. A first chamber containing an aqueous solution of an acid, a second chamber containing a waste liquid containing metal ions and connected to the first chamber through a cation exchange membrane, and an aqueous solution of an acid. And a third chamber which is connected to the second chamber via a cation exchange membrane, and a fourth chamber which contains an aqueous solution of an acid and is connected to the third chamber via an anion exchange membrane. An anode disposed in the first chamber in contact with the acid aqueous solution, a cathode disposed in the fourth chamber in contact with the acid aqueous solution, and a DC voltage applied between the anode and the cathode. A waste liquid reclamation treatment device comprising: a power supply for applying the electric power. 6. A waste liquid supply means for supplying the waste liquid to the second chamber, and a regenerated liquid discharge means for discharging the regenerated liquid in the second chamber from which the metal ions have been removed to the outside of the second chamber. The waste liquid recycling apparatus according to claim 5, wherein 7. The waste liquid regeneration treatment apparatus according to claim 6, wherein a partition plate is provided in the second chamber, and a flow path is formed in the second chamber by the partition plate. 8. A partition plate is disposed in the third chamber, a flow path is formed in the third chamber by the partition plate, and a flow direction of the aqueous solution of the acid in the second chamber and a flow of the acid in the third chamber The waste liquid recycling apparatus according to claim 7, wherein the flowing directions of the aqueous solutions are opposite to each other. 9. A partition plate is provided in each of the first chamber and the fourth chamber, a flow path is formed in each of the first chamber and the fourth chamber by the partition plate, and an aqueous solution of an acid in the first chamber is formed. The flowing direction and the flowing direction of the aqueous acid solution in the second chamber are opposite to each other, and the flowing direction of the aqueous acid solution in the third chamber and the flowing direction of the aqueous acid solution in the fourth chamber are mutually opposite. The waste liquid regeneration treatment device according to claim 8, wherein the waste liquid regeneration treatment device is in the reverse direction. 10. The waste liquid regeneration according to claim 5, 6, 7, 8 or 9, further comprising recirculation means for recirculating the acid aqueous solution in the first chamber and the fourth chamber between both chambers. Processing equipment. 11. The recirculation means includes the first chamber and the fourth chamber.
11. A reserve tank for storing a part of an aqueous solution of an acid refluxed between the chambers, and a concentration measuring unit for measuring the concentration of the acid in the reserve tank. The waste liquid recycling apparatus described. 12. A plurality of treatment tanks each including the first chamber, the second chamber, the third chamber, and the fourth chamber are continuously provided, and the fourth chamber of one adjacent treatment tank and the treatment chamber of the other adjacent treatment tank are disposed. The first chamber is shared with the first chamber, and the anode is disposed only in the first chamber located at one end of the consecutive treatment tanks, and the anode is disposed at the other end of the consecutive treatment tanks. The waste liquid recycling apparatus according to claim 5, 6, 7, 8, 9, 10 or 11, wherein the cathode is provided only in four chambers.