JP6689671B2 - Ion exchange material, ion exchanger, ion adsorption device, water treatment system, method for producing ion exchange material, and method for producing ion exchanger - Google Patents

Description

  The present invention relates to an ion exchange material that exchanges ions, an ion exchanger that uses the ion exchange material, an ion adsorption device including the ion exchanger, and a water treatment system. The present invention also relates to a method for manufacturing an ion exchange material and a method for manufacturing an ion exchanger.

  Conventionally, it has been proposed to use an alkali metal titanate compound as an ion exchanger in order to remove or incorporate a specific ion. For example, Patent Document 1 uses sodium titanate as an ion exchanger, and Patent Document 2 uses potassium titanate as an ion exchanger.

Japanese Patent No. 4428541 JP, 2013-246145, A

  As specific ions, particularly radioactive strontium and cesium are removed from contaminated water, further improvement of ion exchange performance is required.

  In view of the above problems, the present invention provides an ion exchange material having excellent ion exchange performance, an ion exchanger using the ion exchange material, and an ion adsorption device and a water treatment system including the ion exchange material. With the goal. Another object of the present invention is to provide a method for producing a titanate compound-based ion exchange material having excellent ion exchange performance and a method for producing a titanate compound-based ion exchanger having excellent ion exchange performance.

  In order to achieve the above object, the ion exchange material according to the present invention is an ion exchange material containing K, Ti, Nb, and O, and has a diffraction angle of 2θ in an X-ray diffraction spectrum using a Cu-Kα radiation source. Has a first peak in the range of 13.0 ° to 13.4 ° and a second peak in which the diffraction angle 2θ is in the range of 11.2 ° to 11.6 ° (first configuration). .

  Further, in the ion exchange material having the first configuration, it is preferable that the intensity ratio of the first peak to the second peak is 2.0 or more and 5.0 or less (second configuration).

In the ion exchanger having the first or second configuration, the atomic ratio of K, Ti, Nb, and O is represented by the general formula K _2x Ti _y Nb _2z O _{x + 2y + 5z} , where x, y, and z are: It is preferable that the configuration (third configuration) satisfies x + y + z = 1, 0.26 ≦ x ≦ 0.60, and 0.02 ≦ z ≦ 0.33.

  To achieve the above object, the ion exchanger according to the present invention has a configuration (fourth configuration) obtained by granulating the ion exchange material having any one of the first to third configurations using a binder.

  In order to achieve the above object, the ion adsorption device according to the present invention has a configuration (fifth configuration) including the ion exchanger having the fourth configuration and a container filled with the ion exchanger.

  In order to achieve the above object, the water treatment system according to the present invention has a configuration (sixth configuration) including the ion adsorption device of the fifth configuration.

In order to achieve the above-mentioned object, the method for producing an ion exchange material according to the present invention comprises a potassium compound that produces K ₂ O or K ₂ O by heating, a titanium compound that produces TiO ₂ or TiO ₂ by heating, and Nb. ₂ O ₅ or a niobium compound that produces Nb ₂ O ₅ by heating is mixed, and a firing step of firing the mixture produced by the mixing step at 700 ° C. or higher and 1000 ° C. or lower, In the mixing step, the molar ratio of K ₂ O, TiO ₂ , and Nb ₂ O ₅ is K ₂ O: TiO ₂ : Nb ₂ O ₅ = x: y: z, and x, y, And z are configurations (seventh configuration) that satisfy x + y + z = 1, 0.26 ≦ x ≦ 0.60, and 0.02 ≦ z ≦ 0.33.

  In order to achieve the above-mentioned object, the method for producing an ion exchanger according to the present invention comprises an ion exchange material having any one of the first to third configurations or an ion exchange material produced by the production method having the seventh configuration. And a binder raw material are mixed and granulated, and a step of heating the granulated product obtained in the mixing / granulating step at 70 ° C. or higher and 1000 ° C. or lower (eighth) Is the configuration).

  The method for producing an ion exchanger according to the present invention is the ion exchange material having any one of the first to third configurations or the ion exchange material produced by the production method having the seventh configuration, and a geopolymer as a binder. It is preferable that the granulated product obtained by mixing and granulating the above raw material is heated at 70 ° C. or higher and 250 ° C. or lower (10th structure).

  According to the present invention, it is possible to provide an ion exchange material having excellent ion exchange performance, an ion exchanger granulated using the ion exchange material, and an ion adsorption device and a water treatment system including the ion exchange material. it can.

  Further, according to the present invention, a method for producing a titanate compound-based ion exchange material excellent in ion exchange performance and a method for producing an ion exchanger using the titanate compound-based ion exchange material excellent in ion exchange performance. It can also be provided.

Flowchart showing an example of steps for producing the ion exchange material of the present invention The flowchart which shows an example of the process of manufacturing the ion exchanger (granulated product) of this invention. Table showing evaluation results regarding ion exchange performance of ion exchange materials X-ray diffraction spectrum of the ion exchange material obtained in Example 1 X-ray diffraction spectrum of the ion exchange material obtained in Reference Example 2 X-ray diffraction spectrum of the ion exchange material obtained in Reference Example 5 X-ray diffraction spectrum of the ion exchange material obtained in Comparative Example 3 X-ray diffraction spectrum of the ion exchange material obtained in Comparative Example 4 Table showing the evaluation results regarding the strength of the ion exchanger (granulated product) Schematic diagram showing a configuration example of a waste liquid treatment apparatus

  Hereinafter, embodiments of the ion exchange material according to the present invention and the ion exchanger (granulated product) according to the present invention will be described.

<Method for producing ion exchange material>
An ion exchange material manufacturing method according to an embodiment of the present invention includes a mixing step and a firing step of firing the mixture produced by the mixing step at 700 ° C. or higher and 1000 ° C. or lower.

In the mixing step, K ₂ O or a potassium compound that produces K ₂ O by heating, TiO ₂ or a titanium compound that produces TiO ₂ by heating, and Nb ₂ O ₅ or Nb ₂ O ₅ by heating are produced. And a niobium compound are mixed. More specifically, in the above mixing step, the molar ratio of K ₂ O, TiO ₂ and Nb ₂ O ₅ is K ₂ O: TiO ₂ : Nb ₂ O ₅ = x: y: z, K ₂ O or a potassium compound that produces K ₂ O by heating, TiO ₂ or a titanium compound that produces TiO ₂ by heating, and Nb ₂ O ₅ or a niobium compound that produces Nb ₂ O ₅ by heating are blended. To be done. x, y, and z satisfy x + y + z = 1, 0.26 ≦ x ≦ 0.60, and 0.02 ≦ z ≦ 0.33.

  According to the above-mentioned manufacturing method, since it is not necessary to perform the solvothermal synthesis step or the hydrothermal synthesis step adopted in Patent Document 1, the manufacturing method is performed as compared with the case where the solvothermal synthesis step or the hydrothermal synthesis step is performed. The time can be shortened and the manufacturing cost can be reduced.

<Ion exchange material of the present invention>
The ion exchange material of the present invention is an ion exchange material containing K, Ti, Nb, and O, and has an diffraction angle 2θ of 13.0 ° to 13.00 in an X-ray diffraction spectrum using a Cu-Kα radiation source. It is a crystalline compound having a first peak in the range of 4 ° and a second peak in which the diffraction angle 2θ is in the range of 11.2 ° to 11.6 °. As the ion exchange material of the present invention, for example, the ion exchange material manufactured by the above-described manufacturing method can be used.

  It is presumed that the above-mentioned first and second peaks are peaks due to K-Ti-Nb-O-based crystals (potassium niobate titanate). Therefore, it is presumed that the ion exchange material of the present invention has a crystal of K-Ti-Nb-O system and has a structure in which part of titanium in potassium titanate having a layered structure is replaced with niobium. The reason why the ion exchange material of the present invention can have higher ion exchange performance than potassium titanate is that the ion exchange material of the present invention is mainly composed of K—Ti—Nb—O type crystals (niobate titanate). It is presumed that this is because substitution of titanium with niobium formed a suitable layered structure by an ion exchange reaction with, for example, strontium or cesium. The method for measuring the ion exchange rate will be described later.

In the ion exchange material of the present invention, the atomic ratio of K, Ti, Nb, and O is represented by the general formula K _2x Ti _y Nb _2z O _{x + 2y + 5z} , where x, y, and z are x + y + z = 1, 0. It is preferable that 26 ≦ x ≦ 0.60 and 0.02 ≦ z ≦ 0.33 are satisfied. By defining the respective ranges of x, y, and z as described above, it is possible to avoid an extremely small amount of potassium, titanium, or niobium, so that it is possible to sufficiently secure potassium exchanged with ions, and , A layered structure suitable for ion exchange is maintained. Therefore, the ion exchange performance can be improved. Preferably, the above x and z satisfy 0.26 ≦ x ≦ 0.45 and 0.02 ≦ z ≦ 0.33. Further considering the strength of the ion exchanger (granulated product) of the present invention containing the ion exchange material of the present invention, it is more preferable that x and z are 0.28 ≦ x ≦ 0.42 and 0.05. ≦ z ≦ 0.18 is satisfied.

  The ion exchange material of the present invention may contain unintended impurities. As long as the amount of impurities is small, the ion exchange performance and the shape retention strength of the ion exchanger (granulated product) of the present invention containing the ion exchange material of the present invention are not significantly affected. That is, the ion exchange material of the present invention containing a small amount of impurities has substantially the same effect as the ion exchange material of the present invention containing no impurities.

  The ion exchange material of the present invention may contain at least one of potassium dititanate and potassium tetratitanate. This is because the characteristics of the ion exchange material of the present invention can be adjusted by using at least one of the characteristics of potassium dititanate and potassium tetratitanate. Further, unreacted raw material titanium oxide may remain in the ion exchange material of the present invention.

<Method for producing ion exchange material of the present invention>
An example of steps for producing the ion exchange material of the present invention will be described.

  FIG. 1 is a flowchart showing an example of steps for producing the ion exchange material of the present invention.

First, titanium dioxide (TiO ₂ ), niobium oxide (Nb ₂ O ₅ ), and potassium carbonate (K ₂ CO ₃ ) measured in a predetermined composition ratio are subjected to a mixing treatment (step S10) to obtain titanium dioxide (TiO _2). ), Niobium oxide (Nb ₂ O ₅ ) and potassium carbonate (K ₂ CO ₃ ). Examples of the mixing process in step S10 include dry mixing using a vibration mill, bead mill, Henschel mixer, and wet mixing in which stirring and mixing are performed in water. In the case of wet mixing, it is necessary to dry the mixed slurry (step S20). For example, a spray drying process using spray drying can be used, but the spray drying process is not limited.

  Next, the powder mixture is subjected to a firing treatment (step S30) to chemically react the powder mixture. This chemical reaction produces an ion exchange material in the form of powder. Examples of the firing conditions in step S30 include a firing temperature of 700 to 1000 ° C. and a firing time of 1 to 5 hours. If the firing temperature is lower than 700 ° C., a large amount of unreacted raw material may remain in the ion exchange material. If the firing temperature exceeds 1000 ° C., the powder may melt and form a lump. If the firing time is less than 1 hour, a large amount of unreacted raw material may remain in the ion exchange material. When the firing time exceeds 5 hours, thermal energy is input and wasted in vain even after the expected completion time of the reaction, which has a sufficient margin, is exceeded. However, each numerical value is merely an example, and an appropriate value changes depending on, for example, the performance of the firing furnace or the temperature measurement position.

  The average particle size of the above-mentioned ion exchange material is preferably 1 to 100 μm. When the average particle size is 1 μm or more, it is easy to handle in industrial production. If the average particle size exceeds 100 μm, it may hinder the uniform mixing property with the binder during the production of the ion exchanger (granulated product). In that case, it is necessary to adjust the particle size by pulverization or the like. . A more preferable average particle diameter is 1 to 30 μm.

  FIG. 2 is a flowchart showing an example of a process for producing the ion exchanger (granulated product) of the present invention from the ion exchange material of the present invention.

  The above-mentioned ion exchange material of the present invention and the binder raw material are mixed (step S40), and then granulated (step S50). At this time, a polyvinyl alcohol solution or the like may be added to promote granulation. The amount of binder added should be within an appropriate range in consideration of the trade-off between the ion exchange performance and the granulation strength related to the amount of binder added. Next to step S50, an ion exchanger (granulated product) which is a porous particle containing the ion exchange material of the present invention is obtained by binding the ion exchange material of the present invention and the raw material of the binder by a firing treatment (step S60). To get

  The granulation process in step S50 is not particularly limited, and includes rolling granulation method, fluidized bed granulation method, mixing stirring granulation method, extrusion granulation method, melt granulation method, spray granulation method, compression granulation method. Method, crushing granulation method and the like. The mixing stirring granulation method and the like have an advantage that step S40 and step S50 can be performed by the same device. The binder raw material to be mixed with the ion exchange material of the present invention is not particularly limited, but the binder is preferably a geopolymer.

A geopolymer is a cured product containing an active filler and an alkali metal silicate. The geopolymer can be obtained by bringing the metal eluted from the active filler into contact with an aqueous alkali metal silicate solution to crosslink the silicic acid complex (SiO ₄ ) of the alkali metal silicate and polymerize it. Geopolymers have high strength. For this reason, the ion-exchange material particles of the present invention are bound to each other via the geopolymer and have excellent mechanical binding force at the binding portion. Therefore, an ion exchanger (granulated product) having a higher strength than that obtained by using another binder can be obtained. Further, the strength of the geopolymer does not decrease due to moisture. Therefore, by using the geopolymer as a binder, an ion exchanger (granulated product) that maintains high strength even after being immersed in water for a long time can be obtained. Further, since the geopolymer exhibits strength at a low temperature of 250 ° C. or lower, it is possible to suppress a reaction that alters the composition and crystal structure of the ion exchange material of the present invention, and the ion exchange of the ion exchange material of the present invention. Less likely to damage the characteristics.

  Examples of the firing conditions in step S40 include a firing temperature of 70 to 1000 ° C. and a firing time of 1 to 48 hours.

  When the binder is a geopolymer, since the strength of the geopolymer develops at a low temperature of 250 ° C. or lower as described above, the firing conditions in step S40 are, for example, a firing temperature of 70 to 250 ° C. and a firing time of 1 to 48 hours. be able to. That is, by using a geopolymer as the binder, the firing temperature in step S40 can be lowered. By setting the firing temperature to 70 ° C. or higher, solidification of the geopolymer can be accelerated. When the binder is a geopolymer, the firing temperature is more preferably 80 to 150 ° C. When the firing temperature is 80 ° C or higher, the solidification of the geopolymer becomes strong, and when the firing temperature is 150 ° C or lower, the rapid boiling of water in the geopolymer can be suppressed, and the binding portion of the geopolymer can be made uniform. Further, if the time for solidification is 1 hour or more, the solidification of the geopolymer becomes strong, and if the time for solidification exceeds 48 hours, the productivity is lowered. The time is preferably 1 hour or more and 48 hours or less.

  When the binder is a geopolymer, in the mixing process of step S40, the ion exchange material and the active filler which is one of the raw materials of the geopolymer are uniformly mixed. As the active filler, for example, metakaolin, mullite, shale shale, fly ash, clay, clay minerals such as calcined sludge, crushed glass, blast furnace slag and the like may be used. Next, in the granulation process of step 50, another raw material of the geopolymer, that is, an alkali metal silicate and water are used. As the alkali metal silicate, for example, a sodium silicate aqueous solution such as water glass or a potassium silicate aqueous solution may be used. Further, the raw material of the geopolymer may include an organic binder. As the organic binder, for example, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, starch or the like may be used.

  Hereinafter, examples of the present invention will be described in more detail, but the present invention is not limited to the following examples. That is, the portions to which known general techniques such as various treatment methods and granulation methods described below can be applied are not limited to the following examples, and the contents are appropriately changed. It goes without saying that it is possible to do.

<Example 1>
(1-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 21.8 parts by weight of titanium oxide and 8.7 parts by weight of niobium oxide were mixed and stirred. Then, 19.5 parts by weight of potassium carbonate was added and the mixture was further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 593 (relative value) in the range of 9.8 ° to 10.3 °. There is a peak, there is a peak of intensity 500 (relative value) in the range of diffraction angle 2θ of 11.2 ° to 11.6 °, and intensity 1813 (in the range of diffraction angle 2θ of 13.0 ° to 13.4 °). (Relative value), there is a peak of intensity 1603 (relative value) in the range of 13.5 ° to 13.8 °, and according to the general formula K _0.64 Ti _0.61 Nb _0.14 O _1.89. It was the ion exchange material represented.

(1-2) Method for producing ion exchanger (granulated product) 10 kg of ion exchange material obtained in (1-1) and 1.0 kg of metakaolin are mixed at high speed by a granulator (Dalton Co., RMO-4H). The high-speed stirring was performed to produce a mixed powder. Then, 2.5 kg of No. 1 sodium silicate (Na ₂ O · 2SiO ₂ ) as water glass was diluted with 1.5 kg of water, and the mixed powder was sprayed and stirred to granulate. The obtained granules were fired in an electric muffle furnace at 150 ° C. for 12 hours in an air atmosphere to obtain ion exchangers. The particle size of the above-mentioned ion exchanger is, for example, about 300 to 600 μm. In Examples 2 to 4, Reference Examples 1 to 8 and Comparative Examples 1 to 7, which will be described later, the particle size of the ion exchanger is, for example, about 300 to 600 μm.

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 °, and the diffraction angle 2θ was 11.2 ° to 11.6. A peak was confirmed in each of the range of 1 °, the diffraction angle 2θ of 13.0 ° to 13.4 °, and the range of 13.5 ° to 13.8 °.

<Example 2>
(2-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 15.3 parts by weight of titanium oxide and 17.0 parts by weight of niobium oxide were mixed and stirred. Then, 17.7 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 857 (relative value) in the range of 9.8 ° to 10.3 °. There is a peak, the diffraction angle 2θ has a peak of intensity 707 (relative value) in the range of 11.2 ° to 11.6 °, and an intensity of 2350 (relative value) in the range of 13.0 ° to 13.4 °. It was an ion exchange material having a peak and represented by the general formula K _0.66 Ti _0.50 Nb _0.34 O _2.18 .

(2-2) Method for producing ion exchanger (granulated product) In the same process as (1-2) except that the firing temperature is 120 ° C. using the ion exchange material obtained in (2-1) An ion exchanger was obtained.

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 °, and the diffraction angle 2θ was 11.2 ° to 11.6. A peak was confirmed in each of the range of 1 ° and the diffraction angle 2θ of 13.0 ° to 13.4 °.

<Example 3>
(3-1) Method for producing ion exchange material 20.0 parts by weight of titanium oxide and 8.4 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 21.6 parts by weight of potassium carbonate was added, and the mixture was further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. The obtained calcined product was analyzed by an X-ray diffraction analyzer and a fluorescent X-ray analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 ° with an intensity of 300 (relative value). There is a peak, there is a peak of intensity 620 (relative value) in the range of diffraction angle 2θ of 11.2 ° to 11.6 °, and a peak of intensity 2250 (relative value) in the range of 13.0 ° to 13.4 °. An ion represented by the general formula K _0.72 Ti _0.57 Nb _0.14 O _1.85 , which has a peak and an intensity of 3163 (relative value) in the range of 13.5 ° to 13.8 °. It was a replacement material.

(3-2) Method for producing ion exchanger (granulated product) An ion exchanger was obtained in the same step as (2-2) using the ion exchange material obtained in (3-1).

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 °, and the diffraction angle 2θ was 11.2 ° to 11.6. The peak was confirmed in each of the range of °, the diffraction angle 2θ of 13.0 ° to 13.4 °, and the diffraction angle 2θ of 13.5 ° to 13.8 °.

<Example 4>
(4-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 14.1 parts by weight of titanium oxide and 15.6 parts by weight of niobium oxide were mixed and stirred. Then, 20.4 parts by weight of potassium carbonate was added, and the mixture was further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 410 (relative value) in the range of 9.8 ° to 10.3 °. There is a peak, the diffraction angle 2θ has a peak of intensity 797 (relative value) in the range of 11.2 ° to 11.6 °, and the intensity of 3483 (relative value) in the range of 13.0 ° to 13.4 °. It was an ion exchange material having a peak and represented by the general formula K _0.78 Ti _0.46 Nb _0.30 O _2.06 .

(4-2) Method for producing ion exchanger (granulated product) In the same step as (1-2) except that the firing temperature is 100 ° C. using the ion exchange material obtained in (4-1) An ion exchanger was obtained.

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 °, and the diffraction angle 2θ was 11.2 ° to 11.6. A peak was confirmed in each of the range of 1 ° and the diffraction angle 2θ of 13.0 ° to 13.4 °.

< Reference example 1 >
(5-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 25.1 parts by weight of titanium oxide and 7.2 parts by weight of niobium oxide were mixed and stirred. Then, 17.7 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. The obtained calcined product was analyzed by an X-ray diffraction analyzer and a fluorescent X-ray analyzer, and as a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 ° with an intensity of 750 (relative value). There is a peak, the diffraction angle 2θ has a peak of intensity 340 (relative value) in the range of 11.2 ° to 11.6 °, and the intensity 970 (relative value) of 13.0 ° to 13.4 °. There was a peak, and there was a peak of intensity 1323 (relative value) in the range of 13.5 ° to 13.8 °, and it was an ion exchange material represented by the general formula K _0.54 Ti _0.67 Nb _0.12 O _1.91 .

(5-2) Method for producing ion exchanger (granulated product) In the same step as (1-2) except that the firing temperature is 200 ° C. using the ion exchange material obtained in (5-1) An ion exchanger was obtained.

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 °, and the diffraction angle 2θ was 11.2 ° to 11.6. The peak was confirmed in each of the range of °, the diffraction angle 2θ of 13.0 ° to 13.4 °, and the diffraction angle 2θ of 13.5 ° to 13.8 °.

< Reference example 2 >
(6-1) Method for producing ion exchange material 10.7 parts by weight of titanium oxide and 23.8 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 15.5 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 403 (relative value) in the range of 9.8 ° to 10.3 °. There is a peak, the diffraction angle 2θ has a peak of intensity 317 (relative value) in the range of 11.2 ° to 11.6 °, and an intensity of 873 (relative value) in the range of 13.0 ° to 13.4 °. It was an ion exchange material having a peak and represented by the general formula K _0.66 Ti _0.40 Nb _0.54 O _2.48 .

(6-2) Method for producing ion exchanger (granulated product) An ion exchanger was obtained in the same step as (5-2) using the ion exchange material obtained in (6-1).

< Reference Example 3 >
(7-1) Method for producing ion-exchange material 22.3 parts by weight of titanium oxide and 3.1 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 24.6 parts by weight of potassium carbonate was added and the mixture was further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. The obtained calcined product was analyzed by an X-ray diffraction analyzer and a fluorescent X-ray analyzer, and as a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 11.2 ° to 11.6 ° with an intensity of 297 (relative value). There is a peak, the diffraction angle 2θ has a peak of intensity 733 (relative value) in the range of 13.0 ° to 13.4 °, and a peak of intensity 9247 (relative value) in the range of 13.5 ° to 13.8 °. It was an ion exchange material having a peak and represented by the general formula K _0.76 Ti _0.60 Nb _0.04 O _1.68 .

(7-2) Method for producing ion exchanger (granulated product) Same as (1-2) except that the ion exchange material obtained in (7-1) is used and the firing is performed at 80 ° C. for 24 hours. An ion exchanger was obtained in the process.

< Reference Example 4 >
(8-1) Method for producing ion exchange material 7.0 parts by weight of titanium oxide and 18.5 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 24.4 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 1083 (relative value) in the range of 11.2 ° to 11.6 °. There is a peak, the diffraction angle 2θ has a peak of intensity 3853 (relative value) in the range of 13.0 ° to 13.4 °, and is an ion exchange material represented by the general formula K _1.06 Ti _0.26 Nb _0.42 O _2.10. It was

(8-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (8-1), an ion exchanger was obtained in the same step as (7-2).

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 11.2 ° to 11.6 ° and the diffraction angle 2θ was 13.0 ° to 13.4. Peaks were confirmed in each of the ° ranges.

<Reference example 5 >
(9-1) Method for producing ion exchange material 4.9 parts by weight of titanium oxide and 24.1 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 21.0 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. The obtained calcined product was analyzed by an X-ray diffraction analyzer and a fluorescent X-ray analyzer, and as a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 11.2 ° to 11.6 ° with an intensity of 1820 (relative value). There is a peak, a diffraction intensity 2θ has a peak of intensity 7713 (relative value) in the range of 13.0 ° to 13.4 °, and is an ion exchange material represented by the general formula K _1.00 Ti _0.20 Nb _0.60 O _2.40. It was

(9-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (9-1), an ion exchanger was obtained in the same step as (7-2).

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 11.2 ° to 11.6 ° and the diffraction angle 2θ was 13.0 ° to 13.4. Peaks were confirmed in each of the ° ranges.

< Reference Example 6 >
(10-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 12.7 parts by weight of titanium oxide and 10.1 parts by weight of niobium oxide were mixed and stirred. Then, 27.2 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 780 (relative value) in the range of 11.2 ° to 11.6 °. There is a peak, the diffraction angle 2θ has a peak of intensity 2503 (relative value) in the range of 13.0 ° to 13.4 °, and an intensity of 1680 (relative value) in the range of 13.5 ° to 13.8 °. It was an ion exchange material having a peak and represented by the general formula K _1.00 Ti _0.40 Nb _0.20 O _1.80 .

(10-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (10-1), an ion exchanger was obtained in the same step as (1-2).

< Reference Example 7 >
(11-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 2.4 parts by weight of titanium oxide and 22.4 parts by weight of niobium oxide were mixed and stirred. Then, 25.3 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 1283 (relative value) in the range of 11.2 ° to 11.6 °. It is an ion exchange material represented by the general formula K _1.24 Ti _0.10 Nb _0.56 O _2.22 , which has a peak and a peak with an intensity of 3453 (relative value) in the diffraction angle 2θ range of 13.0 ° to 13.4 °. It was

(11-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (11-1), an ion exchanger was obtained in the same step as (7-2).

  The obtained ion exchanger was analyzed by an X-ray diffraction analyzer. As a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 11.2 ° to 11.6 ° and the diffraction angle 2θ was 13.0 ° to 13.4. Peaks were confirmed in each of the ° ranges.

< Reference Example 8 >
(12-1) Method for producing ion exchange material 8.4 parts by weight of titanium oxide and 5.9 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 35.7 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 367 (relative value) in the range of 11.2 ° to 11.6 °. There is a peak, the diffraction angle 2θ has a peak of intensity 787 (relative value) in the range of 13.0 ° to 13.4 °, and a peak of intensity 467 (relative value) in the range of 13.5 ° to 13.8 °. It was an ion exchange material having a peak and represented by the general formula K _1.34 Ti _0.27 Nb _0.12 O _1.51 .

(12-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (12-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative Example 1>
(13-1) Method for producing ion exchange material 24.5 parts by weight of niobium oxide was mixed and stirred with 100 parts by weight of water. Then, 25.5 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 1653 (relative value) in the range of 11.2 ° to 11.6 °. It was an ion exchange material having a peak and represented by the general formula K _1.34 Nb _0.66 O _2.32 .

(13-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (13-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative example 2>
(14-1) Method for producing ion exchange material 37.1 parts by weight of niobium oxide was mixed and stirred with 100 parts by weight of water. Then, 12.9 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 307 (relative value) in the range of 9.8 ° to 10.3 °. An ion represented by the general formula K _0.80 Nb _1.20 O _3.40 , which has a peak and a peak of intensity 297 (relative value) in the range of the diffraction angle 2θ of 11.2 ° to 11.6 °. It was a replacement material.

(14-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (14-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative example 3>
(15-1) Method for producing ion exchange material 5.6 parts by weight of titanium oxide and 31.8 parts by weight of niobium oxide were mixed and stirred with 100 parts by weight of water. Then, 12.6 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. The obtained calcined product was analyzed by an X-ray diffraction analyzer and a fluorescent X-ray analyzer, and as a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 ° with an intensity of 253 (relative value). It was an ion exchange material having a peak and represented by the general formula K _0.64 Ti _0.25 Nb _0.86 O _2.97 .

(15-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (15-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative example 4>
(16-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 14.2 parts by weight of titanium oxide and 23.6 parts by weight of niobium oxide were mixed and stirred. Then, 12.3 parts by weight of potassium carbonate was added and the mixture was further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. The obtained calcined product was analyzed by an X-ray diffraction analyzer and a fluorescent X-ray analyzer, and as a result, in the X-ray diffraction spectrum, the diffraction angle 2θ was in the range of 9.8 ° to 10.3 ° with an intensity of 430 (relative value). It was an ion exchange material having a peak and represented by the general formula K _0.50 Ti _0.50 Nb _0.50 O _2.50 .

(16-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (16-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative Example 5>
(17-1) Method for producing ion exchange material With respect to 100 parts by weight of water, 27.1 parts by weight of titanium oxide and 15.0 parts by weight of niobium oxide were mixed and stirred. Then, 7.9 parts by weight of potassium carbonate was added and the mixture was further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 377 (relative value) in the range of 11.2 ° to 11.6 °. It was an ion exchange material having a peak and represented by the general formula K _0.26 Ti _0.75 Nb _0.24 O _2.23 .

(17-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (17-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative example 6>
(18-1) Method for producing ion exchange material 30.4 parts by weight of titanium oxide was mixed and stirred with 100 parts by weight of water. Then, 19.6 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 1187 (relative value) in the range of 9.8 ° to 10.3 °. An ion represented by the general formula K _0.54 Ti _0.73 O _1.73 , which has a peak and a peak of intensity 2697 (relative value) in the range of diffraction angle 2θ of 13.5 ° to 13.8 °. It was a replacement material.

(18-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (18-1), an ion exchanger was obtained in the same step as (1-2).

<Comparative Example 7>
(19-1) Method for producing ion exchange material 26.8 parts by weight of titanium oxide was mixed and stirred with 100 parts by weight of water. Then, 23.2 parts by weight of potassium carbonate was added and further stirred. The mixed solution was spray-dried at 200 ° C and calcined at 800 ° C for 3 hours. As a result of analyzing the obtained baked product with an X-ray diffraction analyzer and a fluorescent X-ray analyzer, the diffraction angle 2θ in the X-ray diffraction spectrum had an intensity of 2280 (relative value) in the range of 13.5 ° to 13.8 °. It was an ion exchange material having a peak and represented by the general formula K _0.66 Ti _0.67 O _1.67 .

(19-2) Method for producing ion exchanger (granulated product) Using the ion exchange material obtained in (19-1), an ion exchanger was obtained in the same step as (1-2).

<Analyzer>
The analyzers used in the above Examples and Comparative Examples are as follows.
X-ray diffractometer: Rigaku Corporation, Ultima 4, measurement by Cu-Kα ray X-ray fluorescence analyzer: Rigaku Corporation, RIX1000
Scanning electron microscope / energy dispersive X-ray analyzer: JEOL Ltd., JSM-6510 / JED-2300
Laser Diffraction Particle Size Analyzer: Microtrac Bell Co., MT3300EX

<Evaluation of ion exchange performance>
0.01 g of each of the ion exchange materials obtained in Examples 1 to 4, Reference Examples 1 to 8 and Comparative Examples 1 to 7 was weighed and put into each poly container (50 mL centrifuge tube). Then, the stable isotope strontium chloride is dissolved in ion-exchanged water so that the strontium concentration is 10 mg / L, the stable isotope cesium chloride is 1 mg / L, and the sodium chloride concentration is 0.3% by mass. 30 mL of this aqueous solution was added to each poly container. After shaking for 1 hour, solid-liquid separation was performed with a centrifuge, and the supernatant was introduced into ICP (Shimadzu Corporation, ICPE-9000) to quantify the strontium concentration after ion exchange. The ratio of the strontium concentration after ion exchange (after shaking for 1 hour) to the strontium concentration before ion exchange (before charging the plastic container) was defined as the ion exchange rate.

<Evaluation of strength>
0.3 g of each ion exchanger (granulated product) obtained in Examples 1 to 4, Reference Examples 1 to 8 and Comparative Examples 1 to 7 was weighed and put into each poly container (50 mL centrifuge tube). Then, 30 mL of the same aqueous solution as used for the evaluation of the ion exchange performance was added to each plastic container and shaken gently, and the turbidity of the supernatant was measured according to JIS K0101 (industrial water test method) using a spectrophotometer (stock). It was measured using Hitachi High-Technologies Corporation, U-2800). The lower the strength of the ion exchanger (granulated product), the more the ion exchanger (granulated product) collapses and the higher the turbidity. That is, there is a negative correlation between the strength of the ion exchanger (granulated product) and the turbidity.

  In this evaluation, if the turbidity is less than 10, it is A (the group with the highest intensity), if the turbidity is 10 or more and less than 20, it is the B (group with the second highest intensity), and the turbidity is 20 or more and less than 30. If the turbidity was 30 or more, it was designated as C (group having the third highest intensity), and D (group having the smallest intensity) was designated.

<Evaluation result>
FIG. 3 is a table showing the evaluation results regarding the ion exchange performance of the ion exchange materials obtained in Examples 1 to 4, Reference Examples 1 to 8 and Comparative Examples 1 to 7. In addition, in FIG. 3, in the X-ray diffraction spectra of the ion exchange materials obtained in Examples 1 to 4, Reference Examples 1 to 8 and Comparative Examples 1 to 7, the diffraction angle 2θ is 9.8 ° to 10.3 °. , The diffraction angle 2θ is 11.2 ° to 11.6 °, the diffraction angle 2θ is 13.0 ° to 13.4 °, and the diffraction angle 2θ is 13.5 ° to 13.8 °. If there are peaks in each range, the intensities (relative values) of those peaks are listed. For example, in the X-ray diffraction spectrum of the ion exchange material obtained in Example 1 shown in FIG. 4, the diffraction angle 2θ is in the range of 9.8 ° to 10.3 ° and the diffraction angle 2θ is 11.2 ° to 11. There are peaks in the range of 6 °, the diffraction angle 2θ of 13.0 ° to 13.4 °, and the diffraction angle 2θ of 13.5 ° to 13.8 °. Further, for example, in the X-ray diffraction spectrum of the ion exchange material obtained in Reference Example 2 shown in FIG. 5, the diffraction angle 2θ is in the range of 9.8 ° to 10.3 °, and the diffraction angle 2θ is 11.2 ° to 11 °. There are peaks in the range of 0.6 ° and in the range of the diffraction angle 2θ of 13.0 ° to 13.4 °. Further, for example, in the X-ray diffraction spectrum of the ion exchange material obtained in Reference Example 5 shown in FIG. 6, the diffraction angle 2θ is in the range of 11.2 ° to 11.6 ° and the diffraction angle 2θ is 13.0 ° to 13. There is a peak in each of the 4 ° ranges. Further, for example, in the X-ray diffraction spectrum of the ion exchange material obtained in Comparative Example 3 shown in FIG. 7, there is a peak in the range of the diffraction angle 2θ of 9.8 ° to 10.3 °. Further, for example, in the X-ray diffraction spectrum of the ion exchange material obtained in Comparative Example 4 shown in FIG. 8, there is a peak in the diffraction angle 2θ of 9.8 ° to 10.3 °. The peak in the range of the diffraction angle 2θ of 9.8 ° to 10.3 ° is a peak caused by crystals of potassium tetratitanate (K ₂ Ti ₄ O ₉ ). The peak in the range of the diffraction angle 2θ of 11.2 ° to 11.6 ° and the peak in the range of the diffraction angle 2θ of 13.0 ° to 13.4 ° are in the K-Ti-Nb-O system crystals as described above. It is presumed to be a peak due to this. The peak in the range of the diffraction angle 2θ of 13.5 ° to 13.8 ° is a peak due to crystals of potassium dititanate (K ₂ Ti ₂ O ₅ ). In the X-ray diffraction spectra of the ion exchange materials obtained in Examples 1 to 4 and Reference Examples 1 to 8 , the diffraction angle 2θ was 13 with respect to the peak in the range of the diffraction angle 2θ of 11.2 ° to 11.6 °. The intensity ratio of the peak in the range of 0.0 ° to 13.4 ° is 2.0 or more and 5.0 or less. However, the ion exchange material according to the present invention is not limited to this peak intensity ratio (2.0 or more and 5.0 or less). A peak in the range of a diffraction angle 2θ of 11.2 ° to 11.6 °, which is estimated to be a peak due to a K—Ti—Nb—O system crystal, and a diffraction angle 2θ of 13.0 ° to 13.4. This is because if there are both peaks in the range of °, it is considered that the ion exchange performance is improved as compared with the case where neither of them exists or the case where neither of them exists. However, if the intensity ratio of the above-mentioned peak (2.0 or more and 5.0 or less), it has been confirmed that the ion exchange performance of the actual sample is improved. Therefore, the intensity ratio of the above-mentioned peak (2 It is preferably 0.0 or more and 5.0 or less). On the other hand, FIG. 9 is a table showing the evaluation results regarding the strength of the ion exchangers (granulated products) obtained in Examples 1 to 4, Reference Examples 1 to 8 and Comparative Examples 1 to 7.

In Examples 1 to 4 and Reference Examples 1 to 8 , the ion exchange rate is 43% or more, whereas in Comparative Examples 1 to 7, the ion exchange rate is 40% or less. In Examples 1 to 4 and Reference Examples 1 to 8 , in the X-ray diffraction spectrum using the Cu-Kα radiation source, the first peak and the diffraction angle 2θ in the range of 13.0 ° to 13.4 ° 2θ has a second peak in the range of 11.2 ° to 11.6 °, while Comparative Examples 1 to 7 do not have both the first peak and the second peak, or It has only one peak or the second peak.

Further, it is represented by the general formula K _2x Ti _y Nb _2z O _{x + 2y + 5z} , where x, y, and z are x + y + z = 1, 0.26 ≦ x ≦ 0.60, and 0.02 ≦ z ≦ 0. The ion exchange material satisfying 33 includes Examples 1 to 4 and Reference Examples 1 to 6 , and does not include Reference Examples 7 to 8 and Comparative Examples 1 to 7. In Examples 1 to 4 and Reference Examples 1 to 6 , the ion exchange rate is 62% or more, whereas in Reference Examples 7 and 8 , the ion exchange rate is 49% or less. Therefore, the above x, y, and z Preferably satisfies x + y + z = 1, 0.26 ≦ x ≦ 0.60, and 0.02 ≦ z ≦ 0.33.

Further, it is represented by the general formula K _2x Ti _y Nb _2z O _{x + 2y + 5z} , and x, y, and z are x + y + z = 1, 0.26 ≦ x ≦ 0.45, and 0.02 ≦ z ≦ 0. The ion exchange material satisfying 33 includes Examples 1 to 4 and Reference Examples 1 to 3 , and does not include Reference Examples 4 to 8 and Comparative Examples 1 to 7. In Examples 1 to 4 and Reference Examples 1 to 3 , the determination result of the ion exchanger (granulated product) strength is A or B, whereas in Reference Examples 4 to 8 , the ion exchanger (granulated product) strength is determined. Since the determination result is C or D, it is more preferable that x, y, and z satisfy x + y + z = 1, 0.26 ≦ x ≦ 0.44, and 0.02 ≦ z ≦ 0.33.

Further, it is represented by the general formula K _2x Ti _y Nb _2z O _{x + 2y + 5z} , and x, y, and z are x + y + z = 1, 0.28 ≦ x ≦ 0.42, and 0.05 ≦ z ≦ 0. The ion exchange material satisfying 18 includes Examples 1 to 4 and does not include Reference Examples 1 to 8 . In Examples 1 to 4, the ion exchange rate is 92% or more and the determination result of the strength of the ion exchanger (granulated product) is A or B, while in Reference Examples 1 and 2 , the ion exchange rate is 67 % Or less, in Reference Examples 4 to 6 , the determination result of the strength of the ion exchanger (granulated product) is C or D, and in Reference Examples 7 and 8 , the ion exchange rate is 49% or less and the ion exchanger ( The granulation product) strength determination result is D. That is, Examples 1 to 4 are excellent in both the ion exchange rate of the ion exchange material and the strength of the ion exchanger (granulated product). This is because when comparing Examples 1 to 4 and Reference Examples 1 to 8 , the ion exchanger (granulated product) strength can be secured when the potassium ion content ratio represented by the value of x is low, but When the ion exchange rate is low and the potassium ion content is high, the ion exchange rate of the ion exchange material is excellent, but the strength of the ion exchanger (granulated product) cannot be ensured. From the above, it is even more preferable that x, y, and z satisfy x + y + z = 1, 0.28 ≦ x ≦ 0.42, and 0.05 ≦ z ≦ 0.18.

  Although the embodiment of the present invention has been described above, the configuration of the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. That is, the above-described embodiments are exemplifications in all respects, and should be considered not to be restrictive, and the technical scope of the present invention is shown by the claims, and It should be understood that the meaning equivalent to the scope of the claims and all modifications falling within the scope are included.

  For example, the ion exchange material according to the present invention may contain substances other than K, Ti, Nb, and O as long as the ion exchange performance is not significantly deteriorated.

  For example, in each example, titanium oxide, niobium oxide, and potassium carbonate were used to generate the ion-exchange material, but instead of the titanium oxide used in each example, a titanium compound that generates the same amount of titanium oxide by heating was used. You may use. Similarly, instead of the niobium oxide used in each example, a niobium compound that produces the same amount of niobium oxide by heating may be used. Similarly, instead of the potassium carbonate used in each example, a potassium compound that produces the same amount of potassium oxide by heating may be used.

  The ion exchanged by the ion exchange material according to the present invention is not particularly limited, but considering the ion exchange performance evaluation in the above-mentioned examples, it can be preferably used as an exchange material for strontium ions, for example.

  The ion exchanger according to the present invention can be used, for example, in a waste liquid treatment device. Here, an example of the configuration of the waste liquid processing apparatus will be described with reference to FIG. The waste liquid treatment apparatus shown in FIG. 10 has a configuration in which a plurality of columns 1 are connected in series by pipes 2. An ion exchanger 3 according to the present invention is packed inside the first-stage (uppermost stream) column 1. The inside of the second-stage column 1 is filled with an ion exchanger containing an ion-exchange material suitable as a cesium ion exchange material, and the inside of the third-stage (downstream) column 1 is exchanged for cobalt ions. It is filled with an ion exchanger containing an ion exchange material suitable as a material. Each column 1 is provided with an inlet 1A and an outlet 1B. Then, in order to prevent the ion exchanger from leaking to the outside of the column 1, a mesh 4 is installed at the inflow port 1A and the outflow port 1B. The flow of the waste liquid can be generated by, for example, providing a pump on the pipe 2 and operating the pump.

1 Column 1A Inlet 1B Outlet 2 Piping 3 Ion exchanger 4 mesh according to the present invention

Claims (8)

An ion exchange material containing K, Ti, Nb, and O, comprising:
In an X-ray diffraction spectrum using a Cu-Kα radiation source, the first peak having a diffraction angle 2θ of 13.0 ° to 13.4 ° and the diffraction angle 2θ of 11.2 ° to 11.6 ° Has a second peak at
The atomic ratio of K, Ti, Nb, and O is represented by the general formula K _2x Ti _y Nb _2z O _{x + 2y + 5z.}
Represented by
x, y, and z are
x + y + z = 1,
0.2 8 ≦ x ≦ 0. 42 , and 0.0 5 ≦ z ≦ 0. 1 8
An ion exchange material that satisfies the requirements.   The ion exchange material according to claim 1, wherein the intensity ratio of the first peak to the second peak is 2.0 or more and 5.0 or less. An ion exchanger obtained by granulating the ion exchange material according to claim 1 or 2 using a binder. An ion adsorption device comprising: the ion exchanger according to claim 3 ; and a container filled with the ion exchanger. A water treatment system comprising the ion adsorption device according to claim 4 . K ₂ O or a potassium compound which produces K ₂ O by heating,
TiO ₂ or a titanium compound that produces TiO ₂ by heating,
A mixing step of mixing Nb ₂ O ₅ or a niobium compound that produces Nb ₂ O ₅ by heating,
A firing step of firing the mixture produced by the mixing step at 700 ° C. or higher and 1000 ° C. or lower,
In the mixing step,
Compounded so that the molar ratio of K ₂ O, TiO ₂ and Nb ₂ O ₅ is K ₂ O: TiO ₂ : Nb ₂ O ₅ = x: y: z,
x, y, and z are
x + y + z = 1,
0.2 8 ≦ x ≦ 0. 42 , and 0.0 5 ≦ z ≦ 0. 1 8
A method for producing an ion exchange material that satisfies the above conditions. After mixing and granulating the ion exchange material according to claim 1 or 2 or the ion exchange material produced by the production method according to claim 6 with a binder raw material, at 70 ° C or higher and 1000 ° C or lower. A method for producing an ion exchanger, comprising the step of heating. The ion exchange material according to claim 1 or 2 , or the ion exchange material produced by the production method according to claim 6 , and a raw material of geopolymer as a binder are mixed and granulated, and then 70 ° C. or higher 250 A method for producing an ion exchanger, comprising a step of heating at a temperature of not higher than ° C.

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