JP2005201729A - Separation recovery method for zirconium and molybdenum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a separation recovery method for Zr and Mo capable of efficiently and economically separating from each other, the Zr and Mo contained in high level radioactive waste liquid and the like generated in a nuclear-related facilities where reprocessing of spent nuclear fuel and production and dismantling process of nuclear materials are conducted. <P>SOLUTION: A solid adsorbent containing TODGA is made in contact to a solution containing Zr and Mo, and Zr in the solution is selectively adsorbed by the TODGA. When TODGA is used as adsorbent, Zr shows prominent adsorptivity in the nitric acid concentration of 4 mol/l or higher and the adsorption distribution coefficient of Zr prominently increases as the increase of nitric acid concentration; however Mo shows little adsorptivity in any concentration of nitric acid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for selectively separating and recovering Zr from a radioactive liquid waste containing zirconium (Zr) and molybdenum (Mo).

  Zr and Mo are contained in the waste liquid derived from the high-level radioactive waste generated in the nuclear-related facility in the reprocessing process of spent nuclear fuel, the manufacturing / dismantling process of nuclear material, and the like.

  High-level waste generated from nuclear-related facilities means fission products and transuranium generated when reprocessing spent nuclear fuel from nuclear power plants to recover useful uranium (U) and plutonium (Pu). This refers to radioactive waste mainly composed of elements (radioactive elements after atomic number 92), and is mainly generated in liquid form from the reprocessing process. In a process for reprocessing spent nuclear fuel called the Purex process currently being industrially used, spent nuclear fuel is dissolved with nitric acid, and tributyl phosphate (hereinafter referred to as TBP) is used as an extractant from the fuel solution. U and Pu are extracted and separated by a solvent extraction method. Various fission products and transuranium elements contained in the fuel solution remain in the extraction residue, and this extraction residue is generated as a high-level radioactive waste solution. In addition, high-level radioactive liquid waste as described above is also generated in the step of dissolving spent nuclear fuel and the step of treating fuel dissolution residue. Furthermore, high-level radioactive liquid waste as described above is also generated in some overseas institutions in the production and production of nuclear materials such as U and Pu, or in the use and dismantling of nuclear materials.

  It should be noted that a disposal plan is currently underway in which the high-level radioactive liquid waste as described above undergoes a nitric acid recovery process and an evaporative concentration process and is finally processed into a vitrified form and then stored in the deep part of the formation.

  In the high-level radioactive liquid waste, in addition to a small amount of U and Pu that were not completely recovered by the above-described reprocessing process, alkali metal elements such as cesium (Cs), strontium (Sr), barium (Ba), etc. Alkaline earth metal elements, rare earth elements such as neodymium (Nd), cerium (Ce), promethium (Pm), yttrium (Y), minor actinide elements such as neptunium (Np), americium (Am), curium (Cm), There are various nuclides of platinum group elements such as palladium (Pd), rhodium (Rh), ruthenium (Ru), and about 40 elements such as Zr, Mo, niobium (Nb), and technetium (Tc). Various elements contained in high-level radioactive liquid waste are separated into several element groups (group separation) according to their radioactivity level, lifespan, exothermic property, etc. This is extremely important from the viewpoints of improving the economics and efficiency of material disposal, reducing the environmental burden, and effectively using resources.

The oxides of Zr and Mo have a high melting point, and it is necessary to increase the melting temperature in accordance with the melting point when producing a vitrified body of high-level radioactive waste. In particular, the solubility limit of MoO ₃ in ordinary molten glass is 3% by weight or less. Moreover, since the oxides of Zr and Mo weaken the mechanical strength of the vitrified body, the content of waste in the glass has to be restricted, which increases the total amount of vitrified body.

By the way, according to the method described in Patent Document 1 and Patent Document 2 published by the present inventors, it is possible to separate and recover Zr from other elements in the high-level radioactive liquid waste together with Mo. Zr and Mo cannot be separated from each other. Zr in high-level radioactive liquid waste also contains radionuclides with an extremely long half-life (the half-life of ⁹³ Zr is 950,000 years), whereas Mo has a stable radionuclide with almost no radioactivity or a very long lifetime. It is a short nuclide and one of the most abundant fission products. The Mo content in the spent nuclear fuel depends on the fuel composition and burnup, etc., but the Mo content in the normal spent nuclear fuel taken out from the light water reactor is about 0.3 to 0.4% by weight. The Mo content in the spent nuclear fuel taken out from the breeder reactor is about 0.6 to 0.7% by weight, and each occupies about 10% of the total weight of the fission product elements.

  Therefore, if Zr and Mo can be separated from the recovered liquid obtained by the method described in Patent Document 1 or Patent Document 2, it is sufficient to easily dispose only Mo as non-radioactive or low-level radioactive waste. Yes, and as a result, it is possible to reduce the volume of high-level radioactive waste. However, since Zr and Mo in the high-level radioactive liquid waste show similar chemical forms and separation behavior, an effective separation method has not been established.

  As described above, when a large amount of Zr and Mo are present in the high-level radioactive liquid waste, the vitrified product production process may be hindered, and the vitrified product amount may be increased. Further, it is possible to separate and recover Zr and Mo from high-level radioactive liquid waste by the methods described in Patent Document 1 and Patent Document 2, but radioactive Zr is non-radioactive in the recovered liquid. Because it is mixed with Mo, it is impossible to treat and dispose only Mo as non-radioactive or low-level radioactive waste. It is connected.

JP 2002-333497 A JP 2004-020546 A

  The present invention has been made to overcome the disadvantages of the conventional method for separating and recovering elements from high-level radioactive liquid waste, and its object is to reprocess spent nuclear fuel and to manufacture and dismantle nuclear materials. To provide a method for separating and recovering Zr and Mo that makes it possible to efficiently and economically separate Zr and Mo contained in high-level radioactive liquid waste generated at nuclear-related facilities performing is there.

  In the method for separating and recovering Zr and Mo according to the present invention, N, N, N ′, N′-tetraoctyl-3-oxapentane-1,5-diamide (hereinafter referred to as TODGA) is added to a solution containing Zr and Mo. ) Containing a solid adsorbent (hereinafter referred to as TODGA adsorbent), and an adsorption step of selectively adsorbing Zr in the solution onto the TODGA adsorbent is provided.

  In the method for separating and recovering Zr and Mo according to the present invention, the TODGA adsorbent that selectively adsorbs Zr in the adsorption step is brought into contact with oxalic acid or diethylenetriaminepentaacetic acid (hereinafter referred to as DTPA), and the TODGA adsorbent is brought into contact with the TODGA adsorbent. An elution step of eluting and collecting the adsorbed Zr is provided after the adsorption step.

  The method for separating and recovering Zr and Mo according to the present invention comprises Zr, Mo, and Shu obtained by treating nitric acid acidic high-level radioactive liquid waste generated in a reprocessing step of spent nuclear fuel as a solution containing Zr and Mo. It is a thing using the collection | recovery liquid containing an acid. Here, this recovered liquid was obtained by processing by the method described in Patent Document 1, and specifically, a bidentate ligand organic compound was added to a high-level radioactive waste liquid containing Zr and Mo. Phosphorus compound adsorbent (for example, octyl (phenyl) -N, N-diisobutylcarbamoylmethylphosphineocid (hereinafter referred to as CMPO) or dihexyl-N, N-diethylcarbamoylmethylphosphonate (hereinafter referred to as CMP)) And Zr and Mo in the waste liquid are adsorbed on the adsorbent, and then the adsorbent is brought into contact with an oxalic acid solution to elute Zr and Mo from the adsorbent.

  The method for separating and recovering Zr and Mo according to the present invention is a solution containing Zr and Mo. Zr, Mo and DTPA obtained by treating a nitric acid high-level radioactive liquid waste generated in a reprocessing step of spent nuclear fuel. It is a thing using the collection | recovery liquid containing this. Here, this recovered liquid was obtained by processing by the method described in Patent Document 2, and specifically, a high-level radioactive waste liquid containing Zr, Mo and the like was treated with an organic phosphorus compound (above-mentioned It is obtained by contacting with an adsorbent containing CMPO or CMP), contacting the adsorbent with an acidic aqueous solution containing DTPA, and eluting elements such as Zr and Mo.

  According to this invention, a solution containing Zr and Mo is brought into contact with a silica / polymer composite carrier-supported TODGA adsorbent that has an excellent ability to adsorb Zr than other adsorbents and has a high adsorption and elution rate. Since it is configured to include an adsorption step for selectively adsorbing Zr in the solution to the TODGA adsorbent, only Zr can be efficiently adsorbed to the TODGA adsorbent from a solution in which Zr and Mo are mixed. There is an effect that Zr and Mo can be reliably separated from each other. In addition, since it is configured to use TODGA for separation of Zr, it is not necessary to use a hydrocarbon diluent such as dodecane for diluting a high concentration of TBP, which has been used in a large amount in the conventional method. Because it is used as an adsorbent, it can significantly reduce the amount of radioactive organic waste liquid that is difficult to post-process in the processing process, and it does not use metal salts or salts containing ammonium in the processing process. There is an effect that concentration radioactive waste liquid is not generated.

  According to the present invention, an elution step in which the TODGA adsorbent that selectively adsorbs Zr in the adsorption step is brought into contact with oxalic acid or DTPA to elute and recover the Zr adsorbed on the TODGA adsorbent is performed after the adsorption step. Since it comprised so that it might comprise, there exists an effect that Zr mutually isolate | separated from Mo can be collect | recovered efficiently and reliably. Therefore, there is an effect that it is possible to improve the efficiency and economical efficiency of the radioactive liquid waste disposal.

  According to the present invention, as a solution containing Zr and Mo, a recovered solution containing Zr, Mo and oxalic acid obtained by treating a nitric acid high-level radioactive liquid waste generated in the reprocessing step of spent nuclear fuel. Since it was configured to use, for example, the recovered liquid obtained by processing by the method described in Patent Document 1 by the present inventors can be used effectively, and combined with the method described in Patent Document 1 By constructing a series of disposal methods, various elements contained in high-level radioactive liquid waste can be separated into groups according to their radioactivity level, lifespan, exothermic nature, etc., and each can be disposed of rationally. There is an effect that it is possible to improve the economical efficiency and efficiency of waste disposal, reduce the environmental load, and effectively use resources.

  According to the present invention, as the solution containing Zr and Mo, the recovered solution containing Zr, Mo and DTPA obtained by treating the nitric acid high-level radioactive waste liquid generated in the reprocessing step of the spent nuclear fuel is used. Thus, for example, the recovered liquid obtained by processing by the method described in Patent Document 2 by the present inventors can be used effectively, and a series combined with the method described in Patent Document 2 is used. By constructing the disposal method, the various elements contained in the high-level radioactive liquid waste can be separated into groups according to their radioactivity level, lifetime, exothermic nature, etc., and rational disposal can be taken respectively. There are effects that it is possible to improve the economics and efficiency of waste disposal, reduce the environmental burden, and effectively use resources.

  The method for separating and recovering Zr and Mo according to the present invention is a solution for adjusting the acidity of a recovered solution containing Zr and Mo obtained by separating and recovering high-level radioactive liquid waste by the methods described in Patent Document 1 and Patent Document 2. An adjustment step, an adsorption step in which the solid adsorbent containing TODGA is brought into contact with the recovered liquid, and Zr in the recovered liquid is adsorbed on the solid adsorbent; and the solid adsorbent is brought into contact with oxalic acid or an aqueous DTPA solution. And an elution step for eluting Zr from the solid adsorbent.

  The outline of the structure of the Zr and Mo separation and recovery method according to the present invention will be described in more detail by dividing it into each step.

1. Solution Preparation Step A recovered solution containing Zr and Mo obtained by treating a high-level radioactive liquid waste by the method described in Patent Document 1 contains about 0.1 mol / l to 1 mol / l complexing agent oxalic acid. It is an acidic solution (hereinafter referred to as recovered liquid A). Moreover, the recovery liquid containing Zr and Mo obtained by processing the high-level radioactive liquid waste by the method described in Patent Document 2 contains a complexing agent DTPA of about 0.01 mol / l to 0.1 mol / l. It is a nitric acid acidic solution (hereinafter referred to as recovery liquid B) having a pH of about 1-2.

  The inventors first examined the adsorption characteristics of the TODGA adsorbent for Zr and Mo in a nitric acid solution. FIG. 1 is a graph showing the relationship between the adsorption partition coefficient of Zr and Mo by the TODGA adsorbent and the nitric acid concentration in the solution. The adsorption partition coefficient is defined as the ratio between the metal concentration in the adsorbent and the metal concentration in the solution at the time of adsorption equilibrium. In FIG. 1, the larger the value of the adsorption distribution coefficient, the stronger the adsorptivity. The TODGA adsorbent used in the test is an adsorbent obtained by impregnating and supporting a TODGA reagent on a silica / polymer composite carrier described later. As is clear from FIG. 1, Zr has a much stronger adsorptivity to the TODGA adsorbent than Mo. That is, it was suggested that mutual separation from Mo is possible by selectively adsorbing Zr with a TODGA adsorbent.

  On the other hand, as described above, complexing agents such as oxalic acid or DTPA coexist in the treatment liquid, and the present inventors further added Zr and Mo in nitric acid solutions in which various concentrations of oxalic acid or DTPA coexisted. The adsorption performance to the TODGA adsorbent was examined. FIG. 1 shows an example of the results of measuring the dependence of the adsorption partition coefficients of Zr and Mo on the nitric acid concentration in a solution containing oxalic acid. As shown in FIG. 1, in a solution containing 0.5 mol / l oxalic acid, Zr shows a remarkable adsorptivity at a nitric acid concentration of about 4 mol / l or more, and the adsorption partition coefficient of Zr increases remarkably with increasing nitric acid concentration. doing. On the other hand, it was recognized that Mo hardly showed adsorptivity at any nitric acid concentration.

  Similarly, FIG. 1 shows an example of the measurement results of the dependence of the adsorption partition coefficients of Zr and Mo on the nitric acid concentration in a solution containing DTPA. As shown in FIG. 1, in a solution containing 0.05 mol / l DTPA, Zr showed a remarkable adsorptivity at a nitric acid concentration of about 2 mol / l or more, and the adsorption partition coefficient of Zr markedly increased as the nitric acid concentration increased. ing. On the other hand, the adsorption partition coefficient of Mo showed a gradual increase with increasing nitric acid concentration, but it was recognized that the adsorptivity was extremely weak compared to Zr.

  Based on these results, it is necessary to first adjust the concentration of nitric acid in the recovered liquid in order to selectively adsorb Zr from the recovered liquid containing Zr and Mo to achieve effective separation from Mo. Naturally, the required concentration of nitric acid also depends on the concentration of oxalic acid and DTPA contained in the recovered liquid. As a result of examining the relationship between the adsorption behavior of Zr and Mo in the presence of various concentrations of oxalic acid and DTPA and the concentration of nitric acid, the present inventors have found that 0.1 mol / l to 1 mol / l in the recovered liquid A. It was found that the concentration of nitric acid required for selective adsorption of Zr was about 3 mol / l to 7 mol / l in a solution containing about oxalic acid. In addition, in the assumed DTPA-containing solution of about 0.01 mol / l to 0.1 mol / l in the recovered liquid B, the nitric acid concentration necessary for selective adsorption of Zr is about 1 mol / l to 4 mol / l. I found. The nitric acid concentration can be easily adjusted by adding high concentration nitric acid or utilizing a known distillation method.

2. Adsorption Step In the present invention, first, Zr in the treatment liquid is adsorbed on the adsorbent by bringing the treatment liquid into contact with the adsorbent. Thereby, Zr is separated from Mo in the solution.

  A known column type or batch type can be preferably used for the adsorption operation. That is, in the column type, the adsorbent is packed in a column and the treatment liquid is passed through, and Zr in the solution is adsorbed on the adsorbent. In the batch method, the treatment liquid and the adsorbent are put in a container and stirred or shaken to adsorb Zr in the solution to the adsorbent. After adsorbing, in order to wash the gaps of the adsorbent and the like, washing treatment is performed with a nitric acid solution having substantially the same concentration as the treatment liquid. Thereby, the whole amount of Mo can be washed out.

  On the other hand, the ion adsorption rate from the solution to the solid adsorbent and the ion elution rate from the solid adsorbent to the aqueous phase solution are governed by the ion diffusion rate in the solid adsorbent. If the particle size of the adsorbent is reduced, it is possible to improve the adsorption and elution rates, but on the other hand, the polymer has the property of swelling in the aqueous phase. The pressure loss at the time will increase significantly. Increased pressure loss reduces the safety of column separation operations, and safety operations are the most important technical issue, especially when treating radioactive waste liquids such as the present invention.

  In order to solve such problems, the present inventors have conducted extensive studies, and as a result, have developed a novel adsorbent in which an organic polymer is supported on porous silica support particles and TODGA is impregnated on a composite support. Since this adsorbent is supported in the pores of spherical porous silica particles having a particle size of several tens to several hundreds of microns, the swelling of the polymer in the aqueous phase solution is effectively suppressed, and the pressure loss during liquid passage is reduced. Remarkably small. Moreover, since the polymer part containing TODGA is shared and supported in silica particles having a small particle size, it has a high adsorption rate and elution rate.

3. Elution Step In order to elute Zr adsorbed on the adsorbent in the adsorption step, the present inventors have intensively studied various eluents and elution conditions. As a result, an effective method for eluting Zr using a solution containing oxalic acid or DTPA was found.

  The above elution operation can be performed in the same manner as the column type and batch type described in the adsorption step. By bringing the adsorbent into contact with the eluent solution, Zr adsorbed on the adsorbent is eluted, and the adsorbent Into the solution phase and separated. The temperature of the elution operation may be in the range of room temperature to about 80 ° C. which can be easily realized industrially as in the adsorption step.

Hereinafter, specific embodiments will be described.
Embodiment 1 FIG.
In the first embodiment, a treatment liquid that simulates a recovery liquid A containing Zr and Mo obtained by treating a high-level radioactive waste liquid generated in a reprocessing process of spent nuclear fuel by the method described in Patent Document 1 ( Hereinafter, it is an example of the separation test of Zr and Mo to which the present invention is applied to the treatment liquid A), and the separation test will be described according to the procedure.

(1) Treatment liquid preparation step As a simulation liquid of the recovery liquid A containing Zr and Mo described in Patent Document 1, about 5 mmol / l Zr (IV) and about 7.5 mmol / l Mo (VI) are included. Prepare a 0.5M oxalic acid solution, add commercially available concentrated nitric acid so that the nitric acid concentration in the solution becomes 6.5 mol / l, and prepare a separation test treatment solution (treatment solution A) having the composition shown in Table 1. Obtained. In addition, the total amount of the processing liquid A introduced into the column in the following separation test is 20 ml.

(2) Column preparation step Adsorption, elution and recovery of Zr and Mo were performed by a column method. A glass column with a jacket having an inner diameter of 1 cm and a length of 22 cm was used as the column, and the column was kept warm by circulating constant temperature water at a temperature of 50 ° C. through the jacket. In this column, a slurry-like TODGA adsorbent carrying 0.5 g TODGA per 1 g silica / polymer composite carrier was packed under pressure. This adsorbent was prepared by preparing a silica / polymer composite carrier by copolymerizing styrene / divinylbenzene in porous silica particles having a particle size of 50 μm and a pore size of 0.6 μm, and then dissolving a solution obtained by dissolving TODGA extractant in dichloromethane solvent. / Soaked in a polymer composite carrier and evaporated to remove the solvent. Next, the adsorbent was conditioned by feeding 50 cm ³ of 6.5 mol / l nitric acid (nitric acid 1) at a flow rate of 1 cm ³ / min from the upper end of the column.

(3) Adsorption process The treatment liquid A was supplied from the upper end of the column by a liquid feed pump at a flow rate of 1 cm ³ / min to adsorb Zr to the adsorbent.

(4) Following the washing step, an aqueous nitric acid solution of concentration 6.5 mol / l in the column (nitrate 2) 70cm ^3, 0.1mol / l aqueous solution of nitric acid (nitric acid 3) 40 cm ^3, pure water 60cm ³ sequentially, the The liquid was passed at a flow rate of 1 cm ³ / min by the same operation as in to wash the adsorbent gap and the inner wall of the column.

(5) Elution Step Next, 100 cm ³ of 0.5 mol / l oxalic acid aqueous solution was supplied to the column at a flow rate of 1 cm ³ / min by the same operation as described above.

(6) Sampling / Analysis 10 cm ^{3 of} the solution flowing out from the lower end of the column during the period of passing through the column was collected by the fraction collector, and the metal concentration in each fraction collecting liquid was analyzed by ICP (inductively coupled radio frequency plasma) emission analysis. The relationship between the effluent weight and the concentration of each metal in the effluent was determined. The result is shown in FIG.

  As apparent from FIG. 2, it can be seen that Mo in the processing liquid A supplied to the column in the adsorption step is hardly adsorbed by the adsorbent and flows out together with the supplied processing liquid and the subsequent cleaning liquid. On the other hand, the same amount of Zr is adsorbed by the adsorbent in the adsorption process. In the elution step, Zr was effectively eluted and collected with 0.5 mol / l oxalic acid aqueous solution.

Embodiment 2. FIG.
In the second embodiment, a processing liquid (Zr and Mo-containing recovered liquid B obtained by processing a high-level radioactive waste liquid generated in the reprocessing process of spent nuclear fuel by the method described in Patent Document 2 ( Hereinafter, it is an example of the separation test of Zr and Mo to which the present invention is applied to the treatment liquid B), and the separation test will be described according to the procedure.

(1) Treatment liquid preparation step As a simulation liquid of the recovery liquid B containing Zr and Mo described in Patent Document 2, about 5 mmol / l Zr (IV) and about 7.5 mmol / l Mo (VI) are included. A 0.05M DTPA solution was prepared, and commercial concentrated nitric acid was added so that the nitric acid concentration in the solution was 3.0 mol / l, and a separation test treatment liquid (treatment liquid B) having the composition shown in Table 2 was prepared. Obtained. In addition, the total amount of the processing liquid B introduced into the column in the following separation test is 20 ml.

(2) Column preparation step Adsorption, elution and recovery of Zr and Mo were performed by a column method. A glass column with a jacket having an inner diameter of 1 cm and a length of 22 cm was used as the column, and the column was kept warm by circulating constant temperature water at a temperature of 50 ° C. through the jacket. In this column, a slurry-like TODGA adsorbent carrying 0.5 g TODGA per 1 g silica / polymer composite carrier was packed under pressure. This adsorbent was prepared by copolymerizing styrene / divinylbenzene into porous silica particles having a particle diameter of 50 μm and a pore diameter of 0.6 μm to prepare a silica / polymer composite carrier, and then dissolving a TODGA extractant in a dichloromethane solvent. / Soaked in a polymer composite carrier and evaporated to remove the solvent. Next, the adsorbent was conditioned by feeding 50 cm ³ of 3.0 mol / l nitric acid (nitric acid 1) at a flow rate of 1 cm ³ / min from the upper end of the column.

(3) Adsorption process The treatment liquid B was supplied from the upper end of the column by a liquid feed pump at a flow rate of 1 cm ³ / min to adsorb Zr to the adsorbent.

(4) Following the washing step, an aqueous nitric acid solution of concentration 3.0 mol / l in the column (nitrate 2) 70cm ^3, 0.1mol / l aqueous solution of nitric acid (nitric acid 3) 40 cm ^3, pure water 60cm ³ sequentially, the The liquid was passed at a flow rate of 1 cm ³ / min by the same operation as in to wash the adsorbent gap and the inner wall of the column.

(5) Elution Step Next, 100 cm ³ of 0.5 mol / l oxalic acid aqueous solution was supplied to the column at a flow rate of 1 cm ³ / min by the same operation as described above.

(6) Sampling / Analysis 10 cm ^{3 of} the solution flowing out from the lower end of the column during the period of passing through the column was collected by the fraction collector, and the metal concentration in each fraction collecting liquid was analyzed by ICP (inductively coupled radio frequency plasma) emission analysis. The relationship between the effluent weight and the concentration of each metal in the effluent was determined. The result is shown in FIG.

  As is apparent from FIG. 3, it can be seen that Mo in the treatment liquid B supplied to the column in the adsorption step is hardly adsorbed by the adsorbent and flows out together with the supplied treatment liquid and the subsequent cleaning liquid. On the other hand, the same amount of Zr is adsorbed by the adsorbent in the adsorption process. In the elution step, Zr was effectively eluted and collected with 0.5 mol / l oxalic acid aqueous solution.

It is a graph which shows the adsorption | suction distribution coefficient of Zr and Mo to the TODGA adsorbent from the nitric acid solution, the nitric acid solution containing oxalic acid, and the nitric acid solution containing DTPA. It is a graph which shows the result of the column separation test which implemented the separation and recovery method of Zr and Mo by Embodiment 1 of this invention using the simulated solution of the radioactive waste liquid containing Zr and Mo. It is a graph which shows the result of the column separation test which implemented the separation recovery method of Zr and Mo by Embodiment 2 of this invention using the simulation solution of the radioactive waste liquid containing Zr and Mo.

Claims (4)

  A solution containing zirconium and molybdenum is contacted with a solid adsorbent containing N, N, N ′, N′-tetraoctyl-3-oxapentane-1,5-diamide, and the zirconium in the solution is brought into contact with the zirconium. A method for separating and recovering zirconium and molybdenum, comprising an adsorption step of selectively adsorbing to an adsorbent.   An elution step is provided after the adsorption step in which the adsorbent that selectively adsorbs zirconium in the adsorption step is brought into contact with oxalic acid or diethylenetriaminepentaacetic acid to elute and collect the zirconium adsorbed on the adsorbent. 2. The method for separating and recovering zirconium and molybdenum according to claim 1.   The solution containing zirconium and molybdenum is a recovered solution containing zirconium, molybdenum, and oxalic acid obtained by treating high-level nitric acid waste liquid generated in the reprocessing step of spent nuclear fuel. The method for separating and recovering zirconium and molybdenum according to claim 1 or 2.   The solution containing zirconium and molybdenum is a recovered solution containing zirconium, molybdenum, and diethylenetriaminepentaacetic acid obtained by treating a high-level nitric acid waste liquid generated in the reprocessing step of spent nuclear fuel. The method for separating and recovering zirconium and molybdenum according to claim 1 or 2.

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