Method for separating and regenerating anion exchange resin and cation exchange resin in mixed ion exchange resin

Abstract

The anion exchange resin mixed with the ion exchange resin and the separation and regeneration method of the cation exchange resin are composed of a separation tower, a cation exchange resin regeneration tower, a concentrated alkali specific gravity separation tower (anion exchange resin height separation tower), and the anion exchange resin and a NaOH solution (NaOH solution). The anion exchange resin and the cation exchange resin have an intermediate specific gravity solution). A small amount of cation exchange resin is mixed into the anion exchange resin taken out in the separation step. Therefore, the anion exchange resin is put into a mixing tank, after moisture is removed, a NaOH solution is injected, and the anion exchange resin is immersed. The NaOH solution is set to be the intermediate specific gravity of anion exchange resin and cation exchange resin. In addition, the anion exchange resin and the NaOH solution are conveyed to a concentrated alkali specific gravity separation tower together. If the method is used for separating and regenerating the anion exchange resin and the cation exchange resin, the anion exchange resin and the cation exchange resin can be separated until the precision is extremely low by utilizing a concentrated alkali specific gravity separation method.

Description

Technical Field

[0001] The present invention relates to a method for separating and regenerating an anion exchange resin and a cation exchange resin used in a non-regenerative ion exchange device, a mixed bed ion exchange device, etc., which are used in a pure water production device, etc. Background Art

[0002] In a pure water manufacturing device, impurities in raw water are removed to improve the cleanliness of water. A mixed bed ion exchange device filled with a mixed ion exchange resin formed by mixing an anion exchange resin and a cation exchange resin is usually used to remove ionic impurities, i.e., anionic impurities and cationic impurities. In the mixed bed ion exchange device, if the ions of the ion exchange resin equivalent to the ion exchange capacity are exchanged, more ionic impurities cannot be removed and penetration occurs. Therefore, after a certain degree of treated water is treated, the ion exchange resins are respectively recovered from the mixed bed ion exchange device, and then regenerated with hydrochloric acid, caustic soda, etc. in a cation exchange resin regeneration tower and anion exchange resin regeneration tower for reuse. At this time, usually, water is passed in an upward flow manner and the difference in sedimentation velocity caused by the difference in specific gravity between the anion exchange resin and the cation exchange resin is used to separate the anion exchange resin from the cation exchange resin.

[0003] An example of a separation column of the mixed ion exchange resin is shown in Figure 5 .exist Figure 5 In the separation tower 21 of the mixed ion exchange resin, a water injection and discharge port 22 is provided at the bottom of the cylindrical separation tower body 21A, and a water supply pipe 23 as a water outlet having a plurality of spray nozzles 23A is provided, and a drain port 24 is formed at the top. A water collecting plate 25 is arranged below the spray nozzle 23A of the separation tower body 21A. In addition, an anion exchange resin extraction pipe 26 as an anion exchange resin extraction part is provided near the middle of the vertical direction in the separation tower 21, and a cation exchange resin extraction pipe 27 is provided below the anion exchange resin extraction pipe 26 and slightly above the water supply pipe 23. In addition, an observation window 28 is formed on the side of the separation tower 21. In addition, 29 is an inlet for the used mixed ion exchange resin provided on the upper side of the side of the separation tower 21.

[0004] In the separation tower 21 of the mixed ion exchange resin, the used mixed ion exchange resin is put into the separation tower 21, and then a NaOH solution of about 4 wt% (hereinafter referred to as NaOH solution) is passed through. After standing for a predetermined time, pure water is injected from the injection and discharge water port 22 and the NaOH solution in the separation tower is squeezed out from the drain port 24 for washing. Then, the separation tower 21 is filled with a predetermined amount of separation water (pure water). At this time, the water surface of the separation water is higher than the upper surface of the mixed ion exchange resin, especially at an upper position of about 500 mm or less.

[0005] Then, air is injected into the separation tower from the injection and discharge water port 24 to bubble the mixed ion exchange resin, and the bubbling is stopped after the resin particles entangled in a colloid state are untied, so that the mixed ion exchange resin is settled on the water collecting plate 25. At this time, the cation exchange resin with a larger specific gravity settles first, and the anion exchange resin with a smaller specific gravity settles later. Then, in order to prepare for backwashing, pure water (separation water) is introduced from the injection and discharge water port 22 to fill the separation tower 21 with water.

[0006] In this water-filled state, pure water is sprayed from the spray nozzle 23A and water is passed in an upward flow, and the separation interface is adjusted to the lower end of the suction port of the anion exchange resin extraction pipe 26 while visually checking from the observation window 28. Then, suction is performed from the anion exchange resin extraction pipe 26, so that the anion exchange resin flows out and is taken out in the form of a mixed phase flow of the anion exchange resin and water. After the water is removed from the mixed phase flow of the anion exchange resin and water, it is transported to the anion exchange resin regeneration tower to perform the regeneration treatment of the anion exchange resin.

[0007] After the anion exchange resin is extracted in this way, pure water is continuously ejected from the ejection nozzle 23A while suction is taken from the cation exchange resin extraction pipe 27 so that it flows out and is taken out in the form of a mixed phase flow of cation exchange resin and water. After the mixed phase flow of the cation exchange resin and water is dehydrated, it is transported to a cation exchange resin regeneration tower to regenerate the cation exchange resin. At this time, the cation exchange resin is not completely taken out, but is left to a certain extent to prevent the mixing of the anion exchange resin.

[0008] However, in the above-mentioned separation and regeneration method of anion exchange resin and cation exchange resin, there is a problem that the separation of the two is insufficient. In particular, the cation exchange resin can be well separated by leaving the interface portion in the separation tower 21, but there is a problem that the cation exchange resin is easily mixed into the anion exchange resin extracted initially.

[0009] Therefore, the concentrated alkali specific gravity separation method (Seprex method) is used, which uses a high concentration of NaOH solution to separate anion exchange resin and cation exchange resin. Figure 6 Process as shown.

[0010] That is, using the aforementioned Figure 5 The separation tower 21 shown in FIG. Figure 6 After the anion exchange resin is extracted in the separation process, it is transported together with the ultrapure water used for separation to a high-precision separation tower (concentrated alkali gravity separation tower (Seprex tower)) for separating the cation exchange resin mixed with a trace amount of anion exchange resin. Into the concentrated alkali gravity separation tower, a NaOH solution with a specific gravity intermediate between the specific gravity of the wet anion exchange resin and the specific gravity of the wet cation exchange resin is injected. For example, Figure 7 As shown, when the specific gravity of the porous anion exchange resin when wetted is 1.05g / mL and the specific gravity of the porous cation exchange resin when wetted is 1.28g / mL, a 16% NaOH solution (specific gravity 1.18g / mL) with an intermediate specific gravity between the two is injected. As a result, the anion exchange resin is suspended, while the cation exchange resin is precipitated, and therefore, the cation exchange resin is extracted and removed from the lower part of the concentrated alkali specific gravity separation tower. Then, pure water is supplied to the tower, and after the NaOH solution is squeezed out and washed, the residual anion exchange resin is extracted (height separation process). The extracted anion exchange resin is transported to the anion exchange resin regeneration tower, and the anion exchange resin is regenerated and washed by conventional methods. On the other hand, the cation exchange resin separated by the separation process in the separation tower is transported to the cation exchange resin regeneration tower, and the cation exchange resin is regenerated and washed by conventional methods. Summary of the invention

[0011] Problems to be solved by the invention

[0012] The cation exchange resin mixed in a small amount into the anion exchange resin can be separated by the concentrated alkali specific gravity separation method as described above. Figure 8 As shown, the anion exchange resin 32 and the cation exchange resin 33 separated by backwash separation in the separation tower 31 are separated, and when the anion exchange resin 32 is transported to the concentrated alkali specific gravity separation tower 34, ultrapure water 36 as separation water is fed into the concentrated alkali specific gravity separation tower 34 from a transport pipe 35 equipped with a pump 35A together with the anion exchange resin 32 ( Figure 8 (a)). Then, if Figure 8 As shown in (b), after the anion exchange resin 32 is put into the concentrated alkali specific gravity separation tower 34, ultrapure water 36 is extracted from the bottom of the concentrated alkali specific gravity separation tower 34. Then, as Figure 8As shown in (c), a NaOH solution 38 having an intermediate specific gravity between the anion exchange resin 32 and the cation exchange resin 33 is injected from the NaOH solution supply pipe 37 at the top of the concentrated alkali specific gravity separation tower 34 to float the anion exchange resin 32 and settle the cation exchange resin 33.

[0013] However, as Figure 8 In the subsequent step (b), the anion exchange resin 32 becomes compact when the ultrapure water as the separation water is extracted, and even if the NaOH solution 38 is injected to float the anion exchange resin 32, the small amount of cation exchange resin 33 contained in the anion exchange resin will not settle. Therefore, there is a problem that the mixing rate of the cation exchange resin 33 in the anion exchange resin 32 cannot be reduced to a very low level. In particular, in the production of highly ultrapure water for semiconductor applications, it is necessary to reduce the mixing rate of the cation exchange resin in the anion exchange resin 32 to the limit.

[0014] The present invention has been made in view of the above problems and has an object to provide a method for separating and regenerating anion exchange resin and cation exchange resin of a mixed ion exchange resin, which can separate anion exchange resin and cation exchange resin to extremely low accuracy by concentrated alkali specific gravity separation.

[0015] Means for solving problems

[0016] In view of the above-mentioned purpose, the present invention provides a method for separating and regenerating an anion exchange resin and a cation exchange resin in a mixed ion exchange resin, which is a method for separating an anion exchange resin and a cation exchange resin from a mixed ion exchange resin of the anion exchange resin and the cation exchange resin, wherein the method for separating and regenerating an anion exchange resin and a cation exchange resin in the mixed ion exchange resin comprises: a separation step, in which the mixed ion exchange resin is introduced into a roughly cylindrical separation tower of the mixed ion exchange resin, which has a mixed ion exchange resin introduction part, an anion exchange resin extraction part arranged in the middle of the vertical direction, a cation exchange resin extraction part arranged below the anion exchange resin extraction part, and an air and separation water injection part arranged at the bottom, and the air and separation water are injected into the separation tower in an upward manner from the air and separation water injection part. The separation tower is provided with separation water to separate the mixed ion exchange resin by utilizing the specific gravity difference; an anion exchange resin conveying step and an anion exchange resin high separation step, in which an anion exchange resin located above the separation interface between the anion exchange resin and the cation exchange resin is extracted from the anion exchange resin extraction section and conveyed to the high separation tower; a cation exchange resin conveying step, in which the residual cation exchange resin is extracted from the cation exchange resin extraction section and conveyed; and an anion exchange resin regeneration step after the high separation step and a cation exchange resin regeneration step after the cation exchange resin conveying step, in which the anion exchange resin conveyed is conveyed to the high separation tower in a state of being immersed in a solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin (Invention 1).

[0017] According to the above invention (Invention 1), in the anion exchange resin transport step, the extracted anion exchange resin is immersed in a solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin. Therefore, during transport, the anion exchange resin is already in a state of suspension while the cation exchange resin is easily precipitated, thereby reducing the mixing rate of the cation exchange resin when the anion exchange resin is separated in the anion exchange resin high separation step.

[0018] In the above invention (Invention 1), it is preferred that the solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin is a NaOH solution (Invention 2).

[0019] According to the above invention (Invention 2), the NaOH solution can have a specific gravity between the specific gravity of the wet anion exchange resin and the specific gravity of the wet cation exchange resin, so that the anion exchange resin can be suspended and the cation exchange resin mixed in the anion exchange resin can be preferably separated.

[0020] In the above invention (Invention 2), it is preferred that in the anion exchange resin transport step, when the anion exchange resin to be transported is transported to the high separation tower in a state of being immersed in a solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin, the anion exchange resin and the NaOH solution are placed in a mixing tank and mixed before being transported to the high separation tower (Invention 3).

[0021] According to the above invention (Invention 3), in the anion exchange resin conveying step, the extracted anion exchange resin is placed in a mixing tank together with a NaOH solution for mixing, and the anion exchange resin is conveyed to the high separation tower in a state of being suspended in advance, thereby further reducing the mixing rate of the cation exchange resin when separating the anion exchange resin.

[0022] In the above inventions (Inventions 1 to 3), it is preferred that the anion exchange resin and / or cation exchange resin is a porous ion exchange resin (Invention 4).

[0023] According to the above invention (Invention 4), the specific gravity of the NaOH solution of more than 5 wt % and less than 30 wt % can be set to a specific gravity between the specific gravity of the porous anion exchange resin when wet and the specific gravity of the porous cation exchange resin when wet. Therefore, the cation exchange resin mixed in the anion exchange resin can be appropriately separated by utilizing the difference in specific gravity between the two.

[0024] Effects of the Invention

[0025] According to the separation and regeneration method of anion exchange resin and cation exchange resin in a mixed ion exchange resin of the present invention, in the anion exchange resin transporting step, the anion exchange resin extracted in the separation step is immersed in a solution having an intermediate specific gravity between the specific gravity of the anion exchange resin when wet and the specific gravity of the cation exchange resin when wet. Therefore, the anion exchange resin is already suspended during transport, and the cation exchange resin is easy to settle, which can reduce the mixing rate of the cation exchange resin when the anion exchange resin is separated in the high separation step. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a process diagram showing a method for separating and regenerating an anion exchange resin and a cation exchange resin of a mixed ion exchange resin according to one embodiment of the present invention.

[0027] Figure 2 It is a schematic diagram showing the conveying step of the anion exchange resin in this embodiment.

[0028] Figure 3 This is a schematic diagram showing the anion exchange resin conveying step of Example 1.

[0029] Figure 4This is a schematic diagram showing the anion exchange resin conveying step of Comparative Example 1.

[0030] Figure 5 This is a schematic diagram showing an example of a separation column of a mixed ion exchange resin including an anion exchange resin and a cation exchange resin.

[0031] Figure 6 This is a process diagram showing a method for separating and regenerating an anion exchange resin and a cation exchange resin of a conventional mixed ion exchange resin by a concentrated alkali gravity separation method.

[0032] Figure 7 This is a schematic diagram showing the principle of the concentrated alkali gravity separation method.

[0033] Figure 8 This is a schematic diagram showing a conventional transport process according to the concentrated alkali gravity separation method. DETAILED DESCRIPTION

[0034] Hereinafter, the method for separating and regenerating an anion exchange resin and a cation exchange resin in a mixed ion exchange resin of the present invention will be described in detail with reference to the drawings.

[0035] [Configuration of separation and regeneration system of mixed ion exchange resin]

[0036] The separation and regeneration method of the anion exchange resin and the cation exchange resin in the mixed ion exchange resin of the present embodiment can be carried out, for example, by the aforementioned Figure 5 The separation is carried out by a structure consisting of a separation tower, a cation exchange resin regeneration tower, a concentrated alkali specific gravity separation tower (anion exchange resin high separation tower), and a mixing tank for mixing the anion exchange resin and the NaOH solution (a solution with an intermediate specific gravity between the anion exchange resin and the cation exchange resin).

[0037] (Mixed ion exchange resin)

[0038] In this embodiment, the mixed ion exchange resin is a mixed resin of anion exchange resin and cation exchange resin. The ratio (volume ratio) of anion exchange resin to cation exchange resin in the mixed ion exchange resin is not particularly limited, and anion exchange resin: cation exchange resin = about 30:70 to 70:30.

[0039] The anion exchange resin and cation exchange resin are preferably porous ion exchange resins. The porous anion exchange resin has a specific gravity of about 1.03 to 1.09 g / mL (when wet), and the porous cationic exchange resin has a specific gravity of about 1.22 to 1.30 g / mL (when wet).

[0040] [Method for separation and regeneration of anion exchange resin and cation exchange resin of mixed ion exchange resin]

[0041] Then, based on Figure 1 The flow chart of FIG. 1 illustrates the separation and regeneration method of the mixed ion exchange resin according to the present embodiment based on the above-mentioned apparatus configuration.

[0042] (Separation process)

[0043] For the separation process, Figure 6 The separation process of the concentrated alkali gravity separation method shown is the same, so its detailed description is omitted.

[0044] (Advanced separation and regeneration process of anion exchange resin)

[0045] A small amount of cation exchange resin is mixed into the anion exchange resin taken out in the separation process. Therefore, in the present embodiment, the anion exchange resin is put into a mixing tank, and after removing the water, a NaOH solution is injected and impregnated. The NaOH solution is set to a concentration of 5 to 30% by weight, which is the intermediate specific gravity of the wetted anion exchange resin and the wetted cation exchange resin. For example, when the anion exchange resin and the cation exchange resin are porous, the NaOH solution is 9 to 25% by weight. This NaOH solution has a specific gravity of about 1.10 to 1.27 g / mL. Specifically, when the specific gravity of the porous anion exchange resin when wet is 1.05 g / mL and the specific gravity of the porous cation exchange resin when wet is 1.28 g / mL, a 16% NaOH solution (specific gravity 1.18 g / mL) of the intermediate specific gravity between the two can be injected.

[0046] After the anion exchange resin and the NaOH solution are mixed in the mixing tank, the anion exchange resin and the NaOH solution are transported to the concentrated alkali specific gravity separation tower (height separation tower). Figure 2 As shown, a mixture 2 of an anion exchange resin and a NaOH solution, which is transported from a separation tower to a mixing tank 1 and then water is removed, is transported from the upper part of a concentrated alkali specific gravity separation tower 4 by a transport pipe 3 equipped with a pump 3A. At this time, the anion exchange resin 5 is suspended in the NaOH solution 7 and the cation exchange resin 6 is precipitated in the NaOH solution 7 while being supplied ( Figure 2 As a result, at the time of completion of the transport to the concentrated alkali specific gravity separation tower 4, the anion exchange resin 5 is suspended and the cation exchange resin 6 is precipitated ( Figure 2(b)). Then, further, as needed, a NaOH solution having an intermediate specific gravity between the anion exchange resin 5 and the cation exchange resin 6 is injected to adjust the amount of liquid in the concentrated alkali specific gravity separation tower 4, and air bubbling is performed and then left to stand to highly separate the anion exchange resin 5 and the cation exchange resin 6. Then, the cation exchange resin 6 is made to flow out and be extracted by suction from the cation exchange resin extraction pipe (not shown) provided at the bottom of the concentrated alkali specific gravity separation tower 4. After the cation exchange resin is dehydrated, it can be put in together at the next separation and regeneration of the mixed ion exchange resin.

[0047] Then, pure water is supplied to the concentrated alkali specific gravity separation tower 4 to squeeze out and discharge the NaOH solution in the tower, and the anion exchange resin 5 is washed and extracted from the concentrated alkali specific gravity separation tower 4. Then, the anion exchange resin can be regenerated by implementing a known regeneration method. Specifically, after the anion exchange resin is added to the anion exchange resin regeneration tower, the NaOH solution is injected to regenerate the anion exchange resin.

[0048] (Cation exchange resin regeneration process)

[0049] The cation exchange resin separated from the separation tower can be regenerated by a known method using a cation exchange resin regeneration tower. Specifically, after the cation exchange resin is put into the cation exchange resin regeneration tower, an HCl solution as an inorganic acid is injected to regenerate the cation exchange resin.

[0050] Then, pure water is supplied to the cation exchange resin regeneration tower to squeeze out and discharge the HCl solution in the tower, and the cation exchange resin is washed. In this way, the cation exchange resin can be regenerated. The regenerated cation exchange resin can be taken out from the cation exchange resin regeneration tower for reuse.

[0051] In the present embodiment as described above, the anion exchange resin 5 separated in the separation process is temporarily received by the mixing tank 1 before being put into the concentrated alkali specific gravity separation tower 4, and is mixed with a NaOH solution of an intermediate specific gravity between the anion exchange resin 5 and the cation exchange resin 6. Therefore, in the concentrated alkali specific gravity separation tower 4, the anion exchange resin 5 will not precipitate, and the cation exchange resin 6 can be separated with high precision.

[0052] The present invention has been described above based on the above-mentioned embodiment, but as long as the anion exchange resin separated in the separation tower is mixed with the NaOH solution of the intermediate specific gravity of the anion exchange resin and the cation exchange resin, and then transported to the high separation tower (concentrated alkali specific gravity separation tower), the present invention can be implemented in various modifications. For example, after the anion exchange resin and the cation exchange resin are highly separated in the high separation tower (concentrated alkali specific gravity separation tower), the residual anion exchange resin can be regenerated in the concentrated alkali specific gravity separation tower.

[0053] The present invention is described in more detail by the following specific examples.

[0054] [Example 1]

[0055] like Figure 3 As shown, after the mixed resin of porous anion exchange resin 5 (specific gravity 1.05 g / mL when wet) and porous cation exchange resin 6 (specific gravity 1.28 g / mL when wet) is separated by separation tower 8, only anion exchange resin 5 is transported to mixing tank 1 together with ultrapure water as separation water to remove water. Then, 16 wt% NaOH solution (specific gravity 1.28 g / mL) is injected into mixing tank 1, the two are mixed, and transported to concentrated alkali specific gravity separation tower 4 from transport pipe 3 equipped with pump 3A. And, in Figure 1 After the anion exchange resin high separation step shown, the cation exchange resin 6 settled at the bottom of the concentrated alkali specific gravity separation tower 4 was extracted, and then the anion exchange resin 5 was extracted. The mixing rate of the cation exchange resin 6 in the extracted anion exchange resin 5 was measured and the result was 0.002 volume %.

[0056] [Comparative Example 1]

[0057] like Figure 4 As shown, after a mixed resin of a porous anion exchange resin 12 (specific gravity when wet: 1.05 g / mL) and a porous cation exchange resin 13 (specific gravity when wet: 1.28 g / mL) is separated by a separation tower 11, only the anion exchange resin 12 is transported together with ultrapure water 15 as separation water from a transport pipe 16 equipped with a pump 16A to a concentrated alkali specific gravity separation tower 14, and water ( Figure 4 (a)). Then, a NaOH solution 18 (specific gravity 1.28 g / mL) having an intermediate specific gravity between the anion exchange resin 12 and the cation exchange resin 13 is injected from the NaOH solution supply pipe 17 at the top of the concentrated alkali specific gravity separation tower 14. Figure 6After the anion exchange resin high separation step shown, the cation exchange resin 13 precipitated at the bottom of the concentrated alkali specific gravity separation tower 14 was extracted, and then the anion exchange resin was extracted. The mixing rate of the cation exchange resin in the extracted anion exchange resin was measured and the result was 0.01 volume %.

[0058] Description of Reference Numerals

[0059] 1: Mixing tank.

[0060] 2: A mixture of anion exchange resin and NaOH solution.

[0061] 3: Delivery pipe.

[0062] 3A: Pump.

[0063] 4: Concentrated alkali gravity separation tower.

[0064] 5: Anion exchange resin.

[0065] 6: Cation exchange resin.

[0066] 7: NaOH solution.

[0067] 8: Separation tower.

[0068] 21: Separation tower of mixed ion exchange resin.

[0069] 21A: separation tower body.

[0070] 22: Inject water into the discharge outlet.

[0071] 23: Water supply pipe.

[0072] 23A: Spray nozzle.

[0073] 24: Drain outlet.

[0074] 25: Water collecting plate.

[0075] 26: Anion exchange resin extraction piping.

[0076] 27: Cation exchange resin extraction piping.

[0077] 28: Observation window.

[0078] 29: Inlet for the used mixed ion exchange resin.

Claims

1. A method for separating and regenerating an anion exchange resin and a cation exchange resin in a mixed ion exchange resin, which is a method for separating an anion exchange resin and a cation exchange resin from a mixed ion exchange resin of an anion exchange resin and a cation exchange resin, wherein: The separation and regeneration method of the anion exchange resin and the cation exchange resin in the mixed ion exchange resin comprises: A separation step, in which a mixed ion exchange resin is introduced into a generally cylindrical separation tower of mixed ion exchange resin, which has a mixed ion exchange resin introduction part, an anion exchange resin extraction part provided in the middle of the vertical direction, a cation exchange resin extraction part provided below the anion exchange resin extraction part, and an air and separation water injection part provided at the bottom, and separation water is introduced into the separation tower in an upward flow manner from the air and separation water injection part to separate the mixed ion exchange resin by using a specific gravity difference; an anion exchange resin conveying step and an anion exchange resin high separation step, in which the anion exchange resin above the separation interface between the anion exchange resin and the cation exchange resin is extracted from the anion exchange resin extraction section and conveyed to a high separation tower; a cation exchange resin transporting step of extracting and transporting the remaining cation exchange resin from the cation exchange resin extracting section; and a regeneration step of the anion exchange resin after the high separation step and a regeneration step of the cation exchange resin after the cation exchange resin transport step, In the anion exchange resin transport step, the anion exchange resin to be transported is transported to the high separation tower in a state of being immersed in a solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin.

2. The method for separating and regenerating an anion exchange resin and a cation exchange resin in a mixed ion exchange resin according to claim 1, wherein: The solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin is a NaOH solution.

3. The method for separating and regenerating an anion exchange resin and a cation exchange resin in a mixed ion exchange resin according to claim 2, wherein: In the anion exchange resin transport step, when the anion exchange resin is transported to the high separation tower in a state of being immersed in a solution having an intermediate specific gravity between the anion exchange resin and the cation exchange resin, the anion exchange resin and the NaOH solution are placed in a mixing tank and mixed before being transported to the high separation tower.

4. The method for separating and regenerating an anion exchange resin and a cation exchange resin in a mixed ion exchange resin according to any one of claims 1 to 3, wherein: The anion exchange resin and / or cation exchange resin is a porous ion exchange resin.

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