KR102342149B1 - A sorbent for radioactive material with prussian blue being coated layered double hydroxides and a preparation method of thereof - Google Patents

Abstract

The present invention relates to a radioactive material adsorbent comprising layered double hydroxides coated with Prussian blue, and to a radioactive material adsorbent comprising layered double hydroxides (LDHs) coated with Prussian blue. .

Description

A sorbent for radioactive material with prussian blue being coated layered double hydroxides and a preparation method of thereof

The removal efficiency is high Layered Double Hydroxide (layered double hydroxides, LDHs) ^- the present invention, iodine (particularly oxidative species, IO ₃₎ relates to a radioactive material adsorbent and a method consisting of a layered double hydroxide coated with Prussian blue By coating with Prussian blue (PB), which has a high selective chemical reaction with cesium, it is possible to adsorb cesium and iodine, which are radioactive materials coexisting in radioactive waste that may be leaked in the event of a nuclear power plant accident or decommissioning, separately or simultaneously. It relates to a radioactive material adsorbent and a method for manufacturing the same.

Since the Fukushima nuclear accident in Japan in 2011, a large amount of radioactive material has been leaked into nature, causing serious environmental pollution problems. , it accumulates upon absorption in the human body and causes serious health problems. To solve this problem, various adsorbents have been developed.

Let's look at Korean Patent Registration No. 10-1920233, which is a prior art related to an iodine adsorbent that adsorbs radioactive iodine, a radioactive material.

The prior art related to an iodine adsorbent relates to an iodine adsorbent containing bismuth graphene oxide capable of efficiently removing iodine, and a fixed bed column or molded article including the same. Specifically, it relates to an adsorbent capable of efficiently removing iodine nuclides emitted during radioactive waste treatment and disposal and a method for manufacturing the same, and a method for preparing bismuth graphene oxide by reacting bismuth with graphene oxide and the prepared The present invention relates to the use of bismuth graphene oxide using bismuth graphene oxide as an iodine adsorbent.

Let's look at Korean Patent Registration No. 10-1708708, which is a prior art for a cesium adsorbent that adsorbs cesium, a radioactive material.

The prior art related to the cesium adsorbent comprises the steps of: a) preparing a mixed solution by adding a ferrocyanide salt to a natural polymer solution; b) preparing an ionic solution comprising trivalent ions; and c) adding the mixed solution prepared in step a) to the ion solution prepared in step b) to form a complex.

However, since cesium and iodine coexisting in radioactive waste must be adsorbed with a cesium adsorbent and an iodine adsorbent, respectively, the treatment process is not simple and the treatment time is required separately, raising a problem in the efficiency of the radioactive material treatment process. to be.

Accordingly, there is an urgent need for research on an adsorbent capable of effectively adsorbing radioactive materials such as cesium and iodine within a short time and increasing the efficiency of the radioactive material removal process.

In order to solve the problems of the prior art described above, it is intended to propose an adsorbent capable of adsorbing cesium and iodine, which are radioactive materials contained in radioactive waste, in a single process within a short time.

Specifically, it is intended to propose an adsorbent capable of adsorbing cesium and iodine, which are radioactive materials, respectively, as well as simultaneously adsorbing and removing cesium and iodine through a single process.

To solve the problems of the prior art, the radioactive material adsorbent according to the present invention includes layered double hydroxides (LDHs) coated with Prussian blue.

Preferably, the layered double hydroxide is a layered double hydroxide represented by the following formula (1).

[Formula 1]

Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O

Here, 0<x<1 and 0<m<15.

The adsorption method for adsorbing a radioactive material according to the present invention in order to solve the problems according to the prior art described above uses layered double hydroxides (LDHs) coated with Prussian blue in iodine and cesium. It includes the step of adsorbing a radioactive material containing any one or more.

Preferably, the layered double hydroxide is a layered double hydroxide represented by the following formula (1).

[Formula 1]

Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O

Here, 0<x<1 and 0<m<15.

In order to solve the problems of the prior art described above, the method for preparing a radioactive material adsorbent according to the present invention comprises the steps of (a) _{mixing layered double hydroxides (LDHs) and ferric chloride (FeCl 3} ) and stirring; and (b) after step (a), potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) is added to the mixture stirred in step (a) and stirred.

Preferably, the layered double hydroxide is a layered double hydroxide represented by the following formula (1).

[Formula 1]

Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O

Here, 0<x<1 and 0<m<15.

Preferably, in step (a), (a-1) each of the layered double hydroxide and the ferric chloride (FeCl ₃ ) is added to each of ultrapure water and stirred to form a layered double hydroxide solution and a ferric chloride (FeCl ₃ ) solution This step is generated; and (a-2) mixing and stirring the layered double hydroxide solution and the ferric chloride (FeCl _{3 ) solution produced in step (a-1).}

Preferably, in the step (a-1), the layered double hydroxide solution is generated by adding it in a mixing ratio of 0.4 to 0.7 g of the layered double hydroxide per 1 ml of ultrapure water.

Preferably, in step (a-1), the ferric chloride (FeCl ₃ ) is added in a mixing ratio of 0.08 to 0.16 g _{per 1 ml of ultrapure water to produce the ferric chloride (FeCl 3} ) solution.

Preferably, in step (a-1), the amount of ultrapure water to which the layered double hydroxide is added and the amount of ultrapure water to which the ferric chloride (FeCl ₃ ) is added are the same.

Preferably, the stirring time in step (a-1) is 0.25 to 0.75 hours.

Preferably, the stirring time in step (a-1) is 0.45 to 0.55 hours.

Preferably, in step (a-2), after the layered double hydroxide solution and the ferric chloride (FeCl ₃ ) solution are mixed, ultrapure water is additionally added to the mixed solution and stirred.

Preferably, in step (a-2), the amount of ultrapure water added to the mixed solution is the same as the amount of ultrapure water added to the layered double hydroxide in step (a-1).

Preferably, the stirring time in step (a-2) is 0.8 to 0.12 hours.

Preferably, in step (b), the potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) is added to ultrapure water and stirred, resulting in potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution This is added to the stirred mixture in step (a-2) and stirred.

Preferably, the potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution is added to a mixing ratio of 0.15 to 0.35 g of the _{potassium ferrocyanide (K 4} [Fe(CN) ₆ ]) per 1 ml of ultrapure water. is created

Preferably, the potassium ferrocyanide _{(K 4 [Fe (CN)} 6]) solution is the potassium ferrocyanide in pure water _{(K 4 [Fe (CN)} 6]) is added and agitated for 0.25 to 0.75 times are generated .

Preferably, in step (b), the potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution is added to the mixture stirred in step (a-2) and stirred for 0.8 to 0.12 hours.

Preferably, (c) after step (b), after the mixture stirred in step (b) is centrifuged in a centrifuge, separating and removing a supernatant of the centrifuged mixture; (d) washing the mixture from which the supernatant was separated and removed in step (c) with ultrapure water; and (e) drying the mixture washed with ultrapure water after step (d).

Due to the above-described problem solving means, it is possible to not only adsorb and remove cesium and iodine, which are radioactive materials that can easily leak into the surrounding environment during a nuclear power plant accident or decommissioning operation, respectively, but also remove cesium and iodine by adsorption at the same time. Therefore, it is possible to simultaneously remove cesium and iodine in a short time by a single adsorption process. The efficiency of the process is increased.

Furthermore, the layered double hydroxide can be coated with Prussian blue to increase the durability of the layered double hydroxide.

1 is a diagram schematically illustrating a process for preparing an adsorbent composed of a layered double hydroxide coated with Prussian blue.
2 is a photograph of layered double hydroxide coated with layered double hydroxide, Prussian blue, and Prussian blue.
3 is a view showing SEM-EDS data for Prussian blue-coated layered double hydroxide after adsorption of cesium and iodine.

Hereinafter, preferred embodiments of the method according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

It will be described with reference to FIG. 1 .

Prussian blue (PB) has a face-centered cubic lattice structure, and the size of the lattice structure is similar to that of a cesium cation, so it is known as a material with excellent selective adsorption efficiency for cesium.

In addition, layered double hydroxides (LDHs) have a positively charged layered structure in which a divalent metal cation is partially substituted with a trivalent metal cation, and an anion and water molecules are gathered in an intermediate layer between the two positively charged layers as a negatively charged layer. is made up At this time, the anions of the intermediate layer may be exchanged with the anions present in the external solution. Layered double hydroxide can control the interlayer spacing according to the chemical composition and manufacturing method, and selectively adsorb anions according to the spacing.

Utilizing these advantages, a Prussian blue-coated layered double hydroxide capable of simultaneously effectively removing cationic cesium and anionic iodine coexisting in radioactive waste was prepared as follows.

1. Preparation of layered double hydroxide coated with Prussian blue

1.1 Layered Double Hydroxide Solution, Ferric Chloride (FeCl) ₃ ) solution and potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) prepare the solution.

The layered double hydroxide solution can be prepared by adding the layered double hydroxide to ultrapure water and stirring. The mixing ratio of ultrapure water and layered double hydroxide may be 0.4 to 0.7 g of layered double hydroxide per 1 ml of ultrapure water, and more preferably 0.5 to 0.6 g.

Here, the layered double hydroxide may be any layered double hydroxide in which the anions of the intermediate layer can be exchanged with iodine anions while Prussian blue is coated, but it may be preferably a layered double hydroxide represented by the following formula (1).

[Formula 1]

Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O

Here, 0<x<1 and 0<m<15.

Hereinafter, the layered double hydroxide represented by Formula 1 is referred to as CoCr layered double hydroxide.

Ferric chloride (FeCl ₃ ) solution can be prepared by adding ferric chloride (FeCl ₃ ) to ultrapure water and stirring. The mixing ratio of the ultra-pure water with ferric chloride (FeCl ₃₎ may be an ultra-pure water 1ml of ferric chloride (FeCl ₃₎ 0.08 to 0.16g per, more preferably from 0.1 to 0.14g.

Potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution may be prepared by adding potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) to ultrapure water and stirring. Potassium cyanide ultra-pure water and Ferro _{(K 4 [Fe (CN)} 6]) , potassium ferrocyanide mixed ratio of deionized water per 1ml of the _{(K 4 [Fe (CN)} 6]) to be 0.15 and 0.35g, and more preferably from 0.2 to 0.3 g.

A layered double hydroxide solution, a ferric chloride (FeCl ₃ ) solution, and a potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution were prepared through the following experiments.

2.714 g of CoCr layered double hydroxide was added to 5 ml of ultrapure water and stirred for 0.5 hours to form a layered double hydroxide solution, and ferric chloride (FeCl ₃ ) was added to 5 ml of ultrapure water and stirred for 0.5 hours with ferric chloride (FeCl ₃ ) A solution was created, and potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) was added to 5 ml of ultrapure water and stirred for 0.5 hours _{to generate a potassium ferrocyanide (K 4} [Fe(CN) ₆ ]) solution.

First, a layered double hydroxide solution and a ferric chloride (FeCl ₃ ) solution are mixed and stirred, and then a potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution is added and stirred, so potassium ferrocyanide ( Of course, the K ₄ [Fe(CN) ₆ ]) solution may be separately prepared during the manufacturing process.

1.2 Layered Double Hydroxide Solution and Ferric Chloride (FeCl) ₃ ) to prepare a mixture of solutions.

The layered double hydroxide solution prepared by the above method and the ferric chloride (FeCl ₃ ) solution may be mixed and stirred. At this time, ultrapure water may be additionally added to the mixture of the layered double hydroxide solution and the ferric chloride (FeCl _{3 ) solution.}

After mixing the layered double hydroxide solution and the ferric chloride (FeCl ₃ ) solution in the following experiment, ultrapure water was further added to prepare a mixture.

After mixing the resulting CoCr layered double hydroxide solution and the resulting ferric chloride (FeCl ₃ ) solution, 5 ml of ultrapure water was additionally added thereto. Then, a mixture of the layered double hydroxide solution and the resulting ferric chloride (FeCl ₃ ) solution to which 5 ml of ultrapure water was added was stirred for 1 hour.

1.3 Layered Double Hydroxide Solution and Ferric Chloride (FeCl) ₃ ) potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) to prepare a mixture by adding the solution.

Potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution may be added to the mixture of the layered double hydroxide solution and the ferric chloride (FeCl _{3 ) solution to prepare a mixture.}

In order to coat Prussian blue on the layered double hydroxide, the layered double hydroxide solution and the ferric chloride (FeCl ₃ ) solution were first mixed, and then potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution was added to the mixture. can do.

The procyan blue synthesis reaction is as follows.

4FeCl ₃ + 4K ₄ [Fe(CN) ₆ ]) --> Fe ₄ [Fe(CN) ₆ ] ₃ + 12KCl

As described above, layered double hydroxides (LDHs) have a positively charged layered structure in which divalent metal cations are partially substituted with trivalent metal cations, and anions and water molecules are gathered in an intermediate layer between two positively charged layers. It consists of a negatively charged layer. At this time, the anions of the intermediate layer may be exchanged with the anions present in the external solution.

The layered double hydroxide according to the present invention may be a CoCr layered double hydroxide. In a state where only CoCr layered double hydroxide exists, iodine anion (IO ₃ ^- ) is exchanged with chlorine anion (Cl ^- ), so that iodine anion (IO ₃ ^- ) can be adsorbed.

However, in order to coat Prussian blue on CoCr layered double hydroxide, ferric chloride (FeCl ₃ ) solution and potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution are simultaneously added to the CoCr layered double hydroxide solution or ferrocyanide potassium _{(K 4 [Fe (CN)} 6]) the solution if the first input, iodide (IO ₃ ^-) is chloride anion (Cl ^{-) - -} cyanide ion (CN) before it is exchanged for a chlorine anions (Cl) can be exchanged for ^{Afterwards, there is no room for exchanging cyanide ions (CN -} ) and iodine anions (IO ₃ ^- ) located in the middle layer of CoCr layered double hydroxide, so that iodine anions (IO ₃ ^- ) cannot be adsorbed with CoCr layered double hydroxide. do.

That is, before Prussian blue is synthesized and coated on CoCr layered double hydroxide, cyanide ions (CN ^- ) are used for chlorine anion (Cl ^- ) exchange, making the synthesis of Prussian blue difficult and the iodine adsorption efficiency significantly lowered. .

^{Therefore, in order not to exchange the chlorine anion (Cl −} ) present in the intermediate layer of CoCr layered double hydroxide, ferric chloride (FeCl ₃ ) solution was first mixed with the CoCr layered double hydroxide solution to coat the surface of the CoCr layered double hydroxide with ferric chloride ( FeCl ₃ ) in the position, potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution was added and ferric chloride (FeCl ₃ ) and potassium ferrocyanide (K ₄ [ By reacting Fe(CN) ₆ ]), Prussian blue can be synthesized on the surface of CoCr layered double hydroxide.

When potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) is added _{while ferric chloride (FeCl 3} ) is positioned on the surface of the CoCr layered double hydroxide, _{potassium ferrocyanide (K 4} [Fe(CN) ₆ ] _{) reacts first with ferric chloride (FeCl 3} ) located on the surface of ^{CoCr layered double hydroxide, so the exchange of chlorine anions (Cl −} ) with cyanide ions (CN ⁻ ) in the middle layer of CoCr layered double hydroxide can be minimized.

In the following experiment, potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution was added to a mixture of a layered double hydroxide solution and a ferric chloride (FeCl _{3 ) solution to prepare a mixture.}

_{Potassium ferrocyanide (K 4} [Fe(CN) ₆ ]) solution produced in a mixture of layered double hydroxide solution and ferric chloride (FeCl ₃ ) solution stirred for 1 hour was added at a rate of 1 ml per minute, and then for 1 hour stirred.

1.4 Layered Double Hydroxide Solution, Ferric Chloride (FeCl) ₃ ) solution and potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) After separating and removing the supernatant from the solution mixture, it is dried.

The layered double hydroxide coated with Prussian blue was prepared by the following experiment.

A mixture of a stirred layered double hydroxide solution, ferric chloride (FeCl ₃ ) solution, and potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution was centrifuged with a centrifuge at 3000 rpm to separate the supernatant and After removal, the mixture was washed 5 times with ultrapure water.

The mixture from which the supernatant was removed by centrifugation was dried at 100° C. for 12 hours.

2. Effect test method

Cs ⁺ and IO ₃ ^- each in a 10 ml solution present at a concentration of 5 ppm, a 10 ml solution present at a concentration of Cs ⁺ 5 ppm and IO ₃ ^{- in} a 10 ml solution each present at a concentration of 5 ppm, CoCr layered double hydroxide, Prussian blue and Prussian blue 10 mg each of the coated CoCr layered double hydroxide was added.

After stirring at 130 rpm for 3 days, the adsorbent (CoCr layered double hydroxide, Prussian blue and Prussian blue coated CoCr layered double hydroxide) was filtered. Thereafter, the cesium and iodine concentrations in the remaining solution were compared with the initial concentrations to examine the removal efficiency according to the adsorption.

3. Effect test result

In Table 1 below, CoCr LDHs refers to CoCr layered double hydroxide, PB refers to Prussian blue, and PB-LDHs refers to Prussian blue-coated CoCr layered double hydroxide.

[Table 1]

In ^{a solution in which Cs +} and IO ₃ ^- exist simultaneously, PB-LDHs shows a ^{high removal efficiency for Cs +} and IO ₃ ^- , whereas PB shows a ^{high removal efficiency only for Cs +} , and in CoCr LDHs, IO ₃ ^- shows high removal efficiency only for

In ^{a solution in which only Cs +} exists, PB-LDHs and PB show high removal efficiency, whereas CoCr LDHs show low removal efficiency.

In _{a solution in which only IO 3} ^- exists, PB-LDHs and CoCr LDHs show high removal efficiency, whereas PB shows low removal efficiency.

It will be described with reference to FIG. 3 .

SEM-EDS image of CoCr layered double hydroxide coated with Prussian blue after adsorption of cesium and iodine. It can be confirmed that the adsorption amounts of Fe, C, N, and Cs, which are the main components of Prussian blue, and the tendency are consistent. In addition, it can be confirmed that the adsorption amount and tendency of Co, Cr and I, which are the main components of the CoCr layered double hydroxide, are consistent.

As a result, it can be seen that cesium and iodine can be simultaneously adsorbed and removed from Prussian blue-coated CoCr layered double hydroxide, PB-LDHs, with high adsorption efficiency.

In the above, the present specification has been described with reference to the embodiments shown in the drawings so that those skilled in the art can easily understand and reproduce the present invention, but these are merely exemplary, and those skilled in the art can make various modifications and equivalent other modifications from the embodiments of the present invention. It will be appreciated that embodiments are possible. Therefore, the protection scope of the present invention should be defined by the claims.

Claims (20)

A radioactive material adsorbent containing layered double hydroxides (LDHs) with chlorine anions (Cl ^{− ) positioned on the intermediate layer and coated with Prussian blue.}
The method of claim 1,
The layered double hydroxide is a radioactive material adsorbent which is a layered double hydroxide represented by the following Chemical Formula 1:

[Formula 1]
Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O
Here, 0<x<1 and 0<m<15.
A chlorine anion (Cl ⁻ ) is located in the intermediate layer and radioactive material containing at least one of iodine and cesium is adsorbed using layered double hydroxides (LDHs) whose surface is coated with Prussian blue. Adsorption method comprising the step of
4. The method of claim 3,
The adsorption method wherein the layered double hydroxide is a layered double hydroxide represented by the following formula (1):

[Formula 1]
Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O
Here, 0<x<1 and 0<m<15.
(a) layered double hydroxides (layered double hydroxides, LDHs) and ferric chloride (FeCl ₃ ) are mixed and stirred;
(b) after step (a), potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) is added to the mixture stirred in step (a) and stirred; and
(f) after step (b), potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) is added in step (b) and the stirred mixture is dried to produce a radioactive material adsorbent,
The radioactive material adsorbent is a method for producing a radioactive material adsorbent in which a chlorine anion (Cl ⁻ ) is located in the intermediate layer and the surface is layered double hydroxides (LDHs) coated with Prussian blue.
6. The method of claim 5,
The method for preparing a radioactive material adsorbent wherein the layered double hydroxide is a layered double hydroxide represented by the following Chemical Formula 1:

[Formula 1]
Co _1-x Cr _x (OH) ₂ Cl _x mH ₂ O
Here, 0<x<1 and 0<m<15.
7. The method of claim 6,
The step (a) is,
(a-1) each of the layered double hydroxide and the ferric chloride (FeCl ₃ ) is added to each ultrapure water and stirred to _{produce a layered double hydroxide solution and a ferric chloride (FeCl 3} ) solution; and
(a-2) The method for producing a radioactive material adsorbent comprising the step of mixing the layered double hydroxide solution and the ferric chloride (FeCl _{3 ) solution produced in the step (a-1) is stirred.}
8. The method of claim 7,
In the step (a-1), the radioactive material adsorbent manufacturing method in which the layered double hydroxide solution is generated by adding the layered double hydroxide to a mixing ratio of 0.4 to 0.7 g per 1 ml of ultrapure water.
9. The method of claim 8,
In the step (a-1), the ferric chloride (FeCl ₃ ) per 1ml of ultrapure water is added so as to have a mixing ratio of 0.08 to 0.16 g _{to produce the ferric chloride (FeCl 3} ) solution. The method of manufacturing the radioactive material adsorbent.
10. The method of claim 9,
In step (a-1), the amount of ultrapure water to which the layered double hydroxide is added and the amount of ultrapure water to which the ferric chloride (FeCl ₃ ) is added are the same as the amount of the radioactive material adsorbent manufacturing method.
11. The method of claim 10,
The stirring time in step (a-1) is 0.25 to 0.75 hours of radioactive material adsorbent manufacturing method.
12. The method of claim 11,
The stirring time in step (a-1) is a radioactive material adsorbent manufacturing method of 0.45 to 0.55 hours.
8. The method of claim 7,
In the step (a-2), after the layered double hydroxide solution and the ferric chloride (FeCl ₃ ) solution are mixed, ultrapure water is additionally added to the mixed solution and stirred.
14. The method of claim 13,
In step (a-2), the amount of ultrapure water additionally added to the mixed solution is the same amount as the amount of ultrapure water to which the layered double hydroxide is added in step (a-1).
15. The method of claim 14,
The stirring time in step (a-2) is 0.8 to 0.12 hours of a radioactive material adsorbent manufacturing method.
8. The method of claim 7,
In the step (b), the potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) is added to ultrapure water and stirred, and the resulting potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution is the (a) -2) A method for producing a radioactive material adsorbent that is added to the stirred mixture in step and stirred.
17. The method of claim 16,
The potassium ferrocyanide (K ₄ [Fe(CN) ₆ ]) solution is added to a mixing ratio of 0.15 to 0.35 g of the _{potassium ferrocyanide (K 4} [Fe(CN) ₆ ]) per 1 ml of ultrapure water, and the radioactive material produced Adsorbent manufacturing method.
18. The method of claim 17,
The potassium ferrocyanide _{(K 4 [Fe (CN)} 6]) solution is the potassium ferrocyanide in pure water _{(K 4 [Fe (CN)} 6]) prepared radioactive material adsorbent is to be input is generated and agitated for 0.25 to 0.75 hours Way.
19. The method of claim 18,
_{In step (b), the potassium ferrocyanide (K 4} [Fe(CN) ₆ ]) solution is added to the mixture stirred in step (a-2), and the radioactive material adsorbent manufacturing method is stirred for 0.8 to 0.12 hours .
17. The method of claim 16,
(c) after step (b), after the mixture stirred in step (b) is centrifuged in a centrifuge, the centrifuged supernatant of the centrifuged mixture is separated and removed;
(d) washing the mixture from which the supernatant was separated and removed in step (c) with ultrapure water; and
(e) after step (d), the radioactive material adsorbent manufacturing method further comprising the step of drying the mixture washed with ultrapure water.

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