JPH06106055A - Method for removing sr ion by adsorption from sr ion containing solution - Google Patents

Abstract

PURPOSE:To obtain an adsorbent that has radiation resistance and is repeatedly used by sintering a hydrous antimony pentaoxide and hydrosol contg. granular substance to form granular antimonic acid and subjecting Sr ions to adsorption and emulsion by it before regenerating it. CONSTITUTION:A hydrous antimony pentaoxide and hydrosol contg. granular substance is sintered at 300-550 deg.C to form granular antimonic acid. And when columns 30, 31 are packed with the granular antimonic acid 32 which is brought into contact with liquid to be treated 51 where Sr ions, etc., are dissolved, the Sr ions are selectively adsorbed and removed. When the granular antimonic acid 32 reaches adsorptive equilibrium, a valve 81 is closed. And after it is immersed in acidic or neutral water solution, it is brought into contact with elution liquid to elute the adsorbed Sr ions. Then, the granular antimonic acid 32 is heated to 300-550 deg.C by an electric furnace 4 to regenerate it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for adsorbing and separating Sr ions from a solution containing Sr ions using granular antimonic acid granulated with an inorganic binder.

[0002]

2. Description of the Related Art High, medium and low level radioactive liquid wastes are examples of discharged liquids containing Sr ions. Of these, the high-level radioactive waste liquid is treated as a vitrified body, but especially when the highly exothermic elements Sr, Cs ions, etc. are present, the vitrified body is destroyed by heat generated from the inside during long-term storage. Inconvenience occurs. From this point of view, the above inconvenience can be avoided by treating the residual waste liquid after separating the Sr and Cs ions from the high-level radioactive waste liquid or the residual waste liquid after separating any one of the Sr and Cs ions. . The separated radioactive Sr and Cs ions are separately processed. By the way, although hydrous antimony pentoxide, which is one of the inorganic ion exchangers, is well known as having high adsorption performance for Sr and Cs ions, it is difficult to handle and industrially difficult to use because it is in powder form. When used industrially, it is well known that other than hydrous antimony pentoxide, they are granulated and used because they are difficult to use in powder form. One of the purposes of granulating these is to change them so that they can be used in a continuous process.
One of the most popular continuous methods in the field of adsorption and separation of specific ions is the column method. In this regard, in order to sufficiently exhibit the performance of the adsorbent in the operation of the device, for example, in order to prevent one-sided flow in the column, etc., it is common practice to reduce the pressure difference between the inlet and outlet of the column. Normally,
The purpose is achieved by increasing the particle size of the packing packed in the column. On the other hand, for granulation of powder, a binder for granulation is required, and an organic binder is often used. A large number of organic binders have also been proposed for hydrous antimony pentoxide. However, in the nuclear field, it is essential to use an inorganic binder having excellent radiation resistance. Against this background, the number of inorganic ion exchangers using an inorganic binder is small, and in particular, an inorganic binder and a granulation method that improve the adsorption performance of hydrous antimony pentoxide have been desired.

[0003]

As described above, one of the adsorbents, hydrous antimony pentoxide, is usually a powder,
When granulating and using it industrially, there were the following subjects. 1) There was a problem in the mechanical strength, especially after the nitric acid treatment in the elution process, even if the powdered hydrous antimony pentoxide alone was granulated. 2) When dealing with radioactive elements, it is particularly preferable to use an inorganic binder having excellent radiation resistance, but the radiation resistance is excellent and the adsorption characteristics after granulation, especially the adsorption characteristics of Sr ions, etc. are improved. There was no inorganic binder. As described above, there is no method in the prior art to obtain granules of hydrous antimony pentoxide having excellent mechanical strength using an inorganic binder having excellent radiation resistance, and it is possible to obtain excellent Sr of hydrous antimony pentoxide. , There was no industrially effective way to utilize Cs ion adsorption performance. Further, there has been awaited a technique capable of separating Sr and Cs ions even in a high acid concentration region, and more preferably a technique capable of separating Sr ions from a high-level radioactive waste liquid.
The present invention is to solve the above problems, and to provide a method for selectively adsorbing and separating Sr ions from a solution containing Sr ions using a granular antimonic acid granulated using an inorganic binder. is there.

[0004]

The above problems can be solved by the adsorption separation method of Sr ions from a solution containing Sr ions according to the present invention, which is characterized by repeating steps A, B and C shown below. . [Step A] Granular antimonic acid obtained by firing a granular material containing hydrous antimony pentoxide and hydrosol at a temperature of 300 ° C. or higher and 550 ° C. or lower is brought into contact with a solution containing Sr ions, and Sr ions are removed from the solution. Adsorption separation step for adsorption separation [Step B] Elution step for immersing the granular antimonic acid obtained in Step A in an acidic or neutral aqueous solution and then contacting with an eluent to elute adsorbed Sr ions from the granular antimonic acid [Step C] A step of regenerating the granular antimonic acid, which is performed by washing and drying the granular antimonic acid which has passed through the step B, and then heating it in a temperature range of 300 ° C. or higher and 550 ° C. or lower. In the case of a suspension containing solid inorganic colloidal particles consisting of one of the Acid can be produced. Furthermore, when the eluent in step B comprises at least one of nitric acid of 3 normal or more and an ammonium nitrate aqueous solution of 0.01 normal or more and 5.0 normal or less, it is more effective to selectively and selectively adsorb Sr ions into granular antimony. Can be eluted from acid.

The granular antimonic acid used in the present invention is
As shown in Example 1 and Comparative Example 1 to be described later, as compared with powdery hydrous antimony pentoxide, Sr ions present in a 2N to 3N nitric acid aqueous solution having an acid concentration of high-level radioactive waste liquid The property of adsorbing and separating is drastically increased, and the property that the adsorbed Sr ion is easily released by just soaking the granular antimonic acid adsorbing at least Sr ion in an aqueous nitric acid solution for several days. After removing the granular antimonic acid from the aqueous nitric acid solution, etc., it is washed and dried, and then re-baked under the specified baking conditions to regain the original adsorption characteristics and the characteristics of releasing the adsorbed Sr ions. It was discovered that there is no problem in mechanical strength and mechanical strength after nitric acid treatment even if the above operation is repeated. As a result of further intensive studies based on these findings, the present inventors have completed the present invention.

First, the granular antimonic acid used in the present invention will be described. One of the starting materials, hydrous antimony pentoxide, is known as an inorganic ion exchanger and is represented by the following general formula (1). Sb ₂ O ₅ · nH ₂ O (1) (However, n is a positive number of 4 or less.) Hydrous antimony pentoxide is known to be crystalline, amorphous, or glassy. It is preferable to use a chemically stable crystal (cubic crystal). As the hydrated antimony pentoxide, one having a value of n of 2 in the general formula represented by the above formula (1) is preferable because a granular body having high mechanical strength can be easily obtained. The preferred particle size of the hydrous antimony pentoxide is 0.01 to 100 μm, and the more preferred particle size is 0.1 to 10 μm. If the particle size is less than 0.01 μm, the powder particles may agglomerate with each other or the surface of the powder may be covered with hydrosol, which may deteriorate the ion exchange characteristics.On the contrary, if it is larger than 100 μm, contact with hydrosol may occur. Since there are few parts, there is a possibility that a granular inorganic ion exchanger having high mechanical strength cannot be obtained. There is no particular limitation on the method for producing hydrous antimony pentoxide,
Any known production method may be used, for example, a method of hydrolyzing antimony pentachloride with water.

Hydrosol, which is another raw material of granular antimonic acid, is a suspension in which solid inorganic colloidal particles are dispersed in water. Preferred examples of hydrosol include:
There are suspensions in which the main component of solid inorganic colloidal particles is silica, alumina, zirconia, titania, or the like. Among these, a suspension containing silica or alumina as a main component of solid inorganic colloidal particles, that is, silica sol or alumina sol is more preferable because a granular inorganic ion exchanger having excellent mechanical strength can be obtained, and silica sol is particularly preferable. It is preferable. As the inorganic colloidal particles constituting the hydrosol, those having a particle size that can be easily obtained by an industrial production method can be used. The smaller the particle size of the inorganic colloidal particles, the larger the mechanical strength. Tends to be obtained. The average particle size of the inorganic colloidal particles forming the hydrosol is preferably 5 to 50 mμ, and more preferably 10 to 30 mμ. It is generally not easy to industrially produce a hydrosol composed of inorganic colloidal particles having an average particle size of less than 5 mμ. When a hydrosol composed of inorganic colloidal particles having an average particle size of more than 50 mμ is used, granules having high mechanical strength can be obtained. May be difficult to obtain. The concentration of the solid content of the hydrosol (metal oxide produced from the hydrosol) is not particularly limited, and the blending amount of the hydrosol may be appropriately adjusted in consideration of the particle size of the hydrous antimony pentoxide to be used. Good. The preferred amount of the hydrosol is 0.3 to 60 as the solid content of the hydrosol (the amount converted to the weight of the metal oxide produced from the hydrosol) per 100 parts by weight of hydrous antimony pentoxide.
The amount is preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight. If the blending amount is less than 0.3 parts by weight, the mechanical strength of the granular inorganic ion exchanger will decrease,
If the amount is more than 60 parts by weight, the ion exchange characteristics of the granular inorganic ion exchanger may be significantly deteriorated.

Granules containing hydrous antimony pentoxide and hydrosol can be obtained by a general molding process for obtaining granules, for example, through the steps of blending, mixing / kneading, granulating and firing. Molded. First, the mixing / kneading step will be described. In the mixing / kneading step, hydrous antimony pentoxide and hydrosol are mixed. At this time, in order to facilitate the mixing / kneading operation, an appropriate amount of water may be added if necessary. The order of mixing is arbitrary, and each component may be uniformly mixed. As an example of the mixing / kneading operation, for example, the above hydrosol may be added to hydrous antimony pentoxide, and the mixture may be uniformly mixed by a kneader or the like, and then an appropriate amount of water may be added and wet-mixed. The slurry obtained as described above is further kneaded with a kneader or the like for several hours to 1 day. The granulation method is also not particularly limited, but it is preferable to use the extrusion granulation method which is excellent in yield and reproducibility on an industrial scale. The obtained granulated product may be spheroidized by an ordinary centrifugal rotation method or the like. Then, the granulated product thus sized is fired to give sufficient mechanical strength to obtain granular antimonic acid. The firing conditions at this time differ depending on the particle size of hydrous antimony pentoxide, the type and blending amount of hydrosol, etc., but the maximum firing temperature during firing must be 300 ° C or higher and 550 ° C or lower. It is preferable to set the temperature above ℃ and below 450 ℃ as the maximum firing temperature. The maximum firing temperature is
If it is less than 300 ° C, the mechanical strength of the granular antimonic acid is lowered, and if it is higher than 550 ° C, the hydrous antimony pentoxide is decomposed, and the ion exchange property of the granular antimonic acid is remarkably lowered. Further, the holding time of the maximum firing temperature is preferably 1 to 8 hours, more preferably 2 to 6 hours. Prior to the main calcination, it is preferably 100 to 200 ° C, more preferably 110 to 200 ° C.
It is advisable to provide a pretreatment step of heating at ˜150 ° C. for 5 hours or more. This step has an advantage that a granular material having high mechanical strength can be obtained. The granules thus obtained are all usable in the present invention, but preferably have a particle size of 0.1 to 10 mm, more preferably 0.2 to 2 mm. If the particle size is smaller than 0.1 mm, the flow resistance when passing through the column is large, and if it is larger than 10 mm, the contact area between the liquid containing cations and the granules is small, so the ion exchange capacity is fully demonstrated. There is a possibility that you cannot do it.

Next, a specific example of the adsorption separation step (step A) in which the granular antimonic acid of the present invention is used to adsorb and separate Sr ions from a solution containing Sr ions will be described. In order to perform the ion exchange treatment using the granular antimonic acid, the granular antimonic acid may be brought into contact with the liquid containing Sr ions. The method of contacting the granular antimonic acid with the liquid is not particularly limited as long as the step of contacting them can be controlled, and may be a batch type or a continuous type.
As a specific example thereof, granular antimonic acid is added to a liquid containing Sr ions and brought into contact with each other by stirring, then, a method of separating the granular antimonic acid, and filling the column or the like with granular antimonic acid, Sr ions There is a method of passing a liquid containing. The preferred time for contacting the granular antimonic acid and the liquid containing Sr ions is not unconditionally determined depending on the object to be treated, but a few minutes to a few hours,
It may take a few days. Further, the temperature at which they are brought into contact with each other may be any number as long as Sr ions are contained in the liquid and the ion exchange characteristics of the granular antimonic acid are maintained. When the granular antimonic acid and the liquid containing Sr ions are brought into contact with each other, the ratio of the granular antimonic acid used is 1 meq of Sr ions.
The amount is preferably 1.0 g or more. Further, other conditions in contacting the granular antimonic acid and the liquid containing Sr ions, for example, the contact time of the granular antimonic acid and the liquid, the contact method or contact temperature, or the pH of the liquid, Sr
It may be appropriately adjusted depending on the ion concentration and the like.

The granular antimonic acid used in the present invention is completely unused and / or granular antimonic acid that has been used more than once is a granular antimonic acid which has been treated through the steps of elution → washing → drying → rebaking described later. It is antimonic acid.

The elution step (step B) in the present invention is carried out using Sr.
After soaking the granular antimonic acid having adsorbed ions in an acidic or neutral aqueous solution, it is contacted with an eluent, preferably an eluent comprising at least one of nitric acid of 3N or more and ammonium nitrate of 0.01N to 5.0N, This is a step of eluting Sr ions. In the present invention, it is necessary to pre-immerse the granular antimonic acid in an acidic or neutral aqueous solution before contacting the granular antimonic acid with the eluent. By this step, the time required to elute the Sr ions adsorbed on the granular antimonic acid can be significantly shortened. The acidic or neutral aqueous solution used for the above purpose is not limited in its type, and as a preferred specific example, 0.
An aqueous solution of nitric acid of 5 normal or more, more preferably 2 normal or more and less than 3 normal, a NaCl aqueous solution of 0.5 normal or more and 1.0 normal or less, Na
Examples include NO ₃ aqueous solution, Na ₂ SO ₄ aqueous solution, and NH ₄ Cl aqueous solution.
As the eluent, one containing a nitric acid group is preferable, and it is most preferable to use an aqueous nitric acid solution from the viewpoint of not introducing impurities from outside the system into the eluent. However, when the adsorbing element group adsorbed on the granular antimonic acid is isolated, it is preferable to use an aqueous ammonium nitrate solution or a combination of this and an aqueous nitric acid solution.

The step of regenerating granular antimonic acid (step C) comprises the following washing step, drying step and re-baking step. The washing step is a step of washing the granular antimonic acid that has been subjected to the elution step B with a washing liquid. The cleaning liquid is a liquid for washing away the eluent adhering to the granular antimonic acid, and specific examples of the preferable cleaning liquid include a nitric acid aqueous solution of 0.1 normal or more and 2 normal or less, an NaCl aqueous solution of 0.5 to 1.0 normal near pH = 7,
There are NaNO ₃ aqueous solution, Na ₂ aqueous solution such as Na ₂ SO ₄ aqueous solution, and NH ₄ Cl aqueous solution, NH ₄ NO ₃ aqueous solution, and NH ₄ salt aqueous solution such as (NH ₄ ) ₂ SO ₄ aqueous solution having the same pH range. The proper use may be determined mainly by the type of eluent used in the elution step. For example, when nitric acid is used as the eluent, a nitric acid aqueous solution of 0.1 N or more is preferably used as the cleaning liquid, and when ammonium nitrate is used as the eluent, any of the above aqueous solutions may be used. It is preferable to use 0.1N nitric acid or a 0.5N to 1.0N NH ₄ NO ₃ aqueous solution in the vicinity of the above pH = 7. The drying step is a step aimed at reducing the water content of the granular antimonic acid that has undergone the washing step to the extent that it can prevent the damage caused by the generation of excessive water vapor in the next firing step, and the temperature is at room temperature. There is no particular problem if it is dried in the range of 150 to 150 ° C. Further, when water is removed in the air flow, air or an inert gas such as nitrogen may be used, and there is no particular limitation. Also, the heating source is not particularly limited. In the re-baking step, the granular antimonic acid whose water content has been reduced in the drying step is used in the range of 300 ° C to 550 ° C, preferably 350 ° C to 450 ° C, usually for 1 hour to 8 hours, preferably 2 hours to 6 hours. This is a process of firing again under the condition of time. The granular antimonic acid reprocessed as described above retains the original ion exchange characteristics and mechanical strength, and is used again in the step A.

Next, an example of an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram for explaining the implementation situation of the adsorption separation method of Sr ions of the present invention. The liquid to be treated 51 in which the Sr ions and the like in the liquid to be treated 1 are dissolved is passed through the lines 6, 7, 8 and 9 in the liquid feed pump 2 to the column 30 or 31.
Sent to. In this example, of the two columns, the column 30 is described as being in a state in which the liquid to be treated is being sent, and the column 31 is as being capable of receiving the liquid to be treated. The columns 30 and 31 can be made of heat resistant glass, ceramics, stainless steel, or the like. Column 30,
31 is filled with granular antimonic acid. Liquid to be treated 51
The Sr ions are selectively adsorbed and separated by the granular antimonic acid 32 packed in the column 30, and the treated liquid after the Sr ion separation goes to another system and is treated separately. When the granular antimonic acid 32 in the column 30 reaches the adsorption equilibrium, the valve 81 is closed and the valve is closed.
After opening 91, the liquid to be treated is passed through the column 31 to continue the Sr ion adsorption step. It is also possible to install a sensor or the like on the lines 12 and 13 and automatically switch the lines, without being limited to this. On the other hand, columns 30 and 31 that selectively adsorbed Sr ions
The granular antimonic acid 32 therein goes through the steps of elution → washing → drying → rebaking, which steps will be described below in sequence. The elution process is as follows. Although the eluent enters the column 30 through the line 16, the line 16 can also serve as the washing liquid insertion line 10 used in a later step and / or the line 15 that guides evaporated water to the outside of the system. . When only 2 to 3 normal nitric acid is used as the eluent, the column 30 is soaked in 2 to 3 normal nitric acid and left for several days. When only nitric acid of 3 normal or more is used as an eluent, the nitric acid concentration may be sequentially increased to reduce the amount of the eluent used, or a method of eluting with nitric acid of 5 normal or more may be combined. An aqueous ammonium nitrate solution may be used as a single eluent, or may be used after partially eluting with the nitric acid, and may be used depending on the purpose. The eluent is stored in the tank 5 through the line 19. The washing process is as follows. The washing solution is poured into the column 30 through the line 16 used in the elution step. The washing of the column 30 and the granular antimonic acid 32 is preferably performed by a batch method. The cleaning liquid is shown as an example of being stored in the tank 5 through the line 19.
You can store it in another tank. The drying process is as follows. After passing through the above steps, air or the like is sent from the line 21 to promote evaporation of water. If the superficial velocity is 5 cm or more per second, there is no particular problem. It is preferable that the evaporated water or the like passes through the line 15 and is condensed by a condenser or the like provided separately and returned to the tank 5. In the drying process, an electric furnace 4 may be used as the heat source. This step can be performed at the same time as the following re-firing step. The re-baking process is as follows. The granular antimonic acid 32 that has undergone the drying step is heated in the electric furnace 4, for example, at 300 ° C to 550 ° C, preferably 350 ° C to 450 ° C.
The following conditions are preferably maintained for 2 hours or more and 6 hours or less. It is not necessary to send air or the like during heating, but it is preferable to use air or the like for promoting heat removal during cooling. At that time, the superficial velocity is not particularly limited. Although the present invention has been described with reference to the column method, which is one of continuous methods, the present invention can also be used in a continuous method, a semi-batch method, a batch method, and / or a combination thereof.

[0014]

EXAMPLES The features of the present invention will be further described in the following examples, but the present invention is not limited thereto. Example 1 200 ml of an aqueous solution containing 2 ppm of nitric acid in which 90 ppm and 130 ppm of Sr ion and Cs ion were dissolved was prepared. 30 g of silica gel as an inorganic binder was mixed with 100 g of water-containing antimony pentoxide and calcined at 400 ° C. for 4 hours to obtain granular antimonic acid. 2.0 g of this granulated antimonic acid was mixed with 200 ml of the aqueous nitric acid solution obtained above, and allowed to stand for 5 days while being kept at 30 ± 1 ° C. The concentrations of Sr and Cs ions in the nitric acid aqueous solution before and after the contact with granular antimonic acid were measured as I.
It was measured by the CP method and the atomic absorption method, and the distribution coefficient Kd defined below was calculated.

[0015]

[Equation 1]

The results are shown in Table 1. Comparative Example 1 The granular antimonic acid of Example 1 was replaced with powdered hydrous antimony pentoxide, and the same operation as in Example 1 was performed. The results are shown in Table 1.
Shown in. From the results of Example 1 and Comparative Example 1, it can be seen that granular antimonic acid has a remarkably higher partition coefficient for Sr ions and has an excellent ability to selectively adsorb Sr ions, as compared with hydrous antimony pentoxide. . Further, granular antimonic acid has a high selective adsorption capacity for Cs ions.

Example 2 The same operation as in Example 1 was carried out by using, instead of the unused granular antimonic acid used in Example 1, granular unused antimonic acid which had been immersed in a 2N nitric acid solution for 4 days. . The results are shown in Table 1.

Example 3 A column having a diameter of 1 cm and a height of 18.7 cm was packed with 22.5 g of the same unused granulated antimonic acid as in Example 1, and the same liquid as in Example 1 was flown with a liquid feed pump at a flow rate of 1.4 ml / min. And the concentration of Sr and Cs ions at the outlet of the column after 50 hours was measured. The results are shown in Table 2.

Example 4 The granular antimonic acid having Sr ions adsorbed in Example 3 was washed with 100 ml of a nitric acid aqueous solution having a pH of about 1 twice and then left in a newly prepared 100 ml of 2N nitric acid aqueous solution at room temperature for 4 days. After that, it was filtered through a filter paper and the concentration of Sr ion in the filtrate was measured.
The results are shown in Table 3.

Example 5 The granular antimonic acid used in Example 4 was mixed with 6% as an eluent.
60 ml of defined nitric acid was fed at a rate of 1 ml / min. Table 3 shows the results of measuring the concentration of Sr ions in the eluent that passed through the column.

Example 6 The granular antimonic acid used in Example 4 was used as an eluent.
30 ml of standard nitric acid and 30 ml of 5 standard ammonium nitrate aqueous solution
60 ml of the mixture consisting of was fed at a rate of 1 ml / min. Table 3 shows the analysis results of the obtained eluent.

Example 7 The granular antimonic acid used in Example 5 was washed with an aqueous solution of about 0.1N nitric acid and dried at room temperature. This granular antimonic acid was baked at 400 ° C. for 4 hours in an electric furnace. The same operation as in Example 3 was performed again using the granular antimonic acid returned to room temperature. The results are shown in Table 2.

Comparative Example 2 The granular antimonic acid used in Example 5 was washed with an aqueous solution of about 0.1N nitric acid and dried at room temperature. The same operation as in Example 3 was carried out using this granular antimonic acid as it was. The results are shown in Table 2.

Example 8 The ion exchange cycle consisting of Example 3, Example 4, Example 5 and Example 7 was repeated 10 times. As a result of measuring the strength of the granular antimonic acid packed in the column with an A type hardness tester,
It was 600 g. This value was the same as the value before starting the ion exchange cycle.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

As described above, the present invention has the following excellent effects. 1) Granular antimonic acid can be continuously operated by a column method because powdery hydrous antimony pentoxide is granulated with an inorganic binder. Also, because it has radiation resistance,
It can be reused repeatedly as long as the adsorption performance does not deteriorate due to other reasons. Therefore, the amount of waste can be reduced as compared with the case where the inorganic ion exchanger is discarded by single use. 2) Granular antimonic acid dramatically increases the adsorption property of Sr ions even under high acid concentrations of 2 N or higher, which could not be achieved by conventional techniques, and therefore selective adsorption of Sr ions under high acid concentrations of 2 N or higher. Separation is possible. In particular, since the high-level radioactive liquid waste is originally discharged at a nitric acid concentration of 2 to 3 N, it is possible to adsorb and separate Sr ions without dilution.

3) Since Sr ions, which are one of the highly exothermic radioactive elements, can be selectively removed, even if the waste liquid after removal of Sr ions is treated as a vitrified body, the heat generated from the inside is halved, so long-term storage Came to withstand. 4) Since it became possible to selectively separate Sr ions with a high acid concentration of 2 N or more, conventionally, in the nuclear field, when the nitric acid concentration was high, the nitric acid concentration was lowered, so denitration, dilution or addition of alkali was performed. Therefore, it has consumed useful resources and extra energy, or has inevitably increased the amount of waste liquid, but such extra operation can be omitted.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... To-be-processed liquid tank 2 ... Liquid-sending pump 4,41 ... Electric furnace 5 ... Tank 6, 7, 8, 9, 10, 11, 12, 13, 14, 1
5,16,17,18,19,20,21,22 ... Line 30, 31 ... Column 32 ... Granular antimonic acid 51 ... Treatment liquid 81, 82, 91, 92 ... Valve

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tomohisa Iinuma 1 Funa-cho, Minato-ku, Nagoya, Aichi Prefecture Toagosei Chemical Industry Co., Ltd. Nagoya Research Institute (72) Inventor Hideki Kato Port, Nagoya, Aichi 1 at Funami-cho, Tokyo-ku Toagosei Synthetic Chemical Industry Co., Ltd. Nagoya Research Institute (72) Inventor, Yuzuru Yanagisawa 314-9 Shinkoga, Mobara-shi, Chiba

Claims (3)

[Claims] 1. A method for adsorbing and separating Sr ions from a solution containing Sr ions, which comprises sequentially repeating the following steps A, B and C. [Step A] Granular antimonic acid obtained by firing a granular material containing hydrous antimony pentoxide and hydrosol at a temperature of 300 ° C. or higher and 550 ° C. or lower is brought into contact with a solution containing Sr ions, and Sr ions are removed from the solution. Adsorption separation step for adsorption separation [Step B] Elution step for immersing the granular antimonic acid obtained in Step A in an acidic or neutral aqueous solution and then contacting with an eluent to elute adsorbed Sr ions from the granular antimonic acid [Step C] Regeneration step of granular antimonic acid which is heated in a temperature range of 300 ° C or higher and 550 ° C or lower after washing and drying the granular antimonic acid which has passed through the step B 2. The Sr ion according to claim 1, wherein the hydrosol in step A is a suspension containing solid inorganic colloidal particles composed of one or a combination of silica, alumina, zirconia, and titania as a main component. Method for adsorptive separation of Sr ions from a solution containing. 3. The adsorption separation of Sr ions from a solution containing Sr ions according to claim 1, wherein the eluent in step B is at least one of nitric acid of 3 normal or more and an ammonium nitrate aqueous solution of 0.01 normal to 5.0 normal. Method.