JP2561831B2 - Separation method of neptunium - Google Patents
Separation method of neptuniumInfo
- Publication number
- JP2561831B2 JP2561831B2 JP62048754A JP4875487A JP2561831B2 JP 2561831 B2 JP2561831 B2 JP 2561831B2 JP 62048754 A JP62048754 A JP 62048754A JP 4875487 A JP4875487 A JP 4875487A JP 2561831 B2 JP2561831 B2 JP 2561831B2
- Authority
- JP
- Japan
- Prior art keywords
- neptunium
- acid
- solution
- npo
- value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G56/00—Compounds of transuranic elements
- C01G56/001—Preparation involving a liquid-liquid extraction, an adsorption or an ion-exchange
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Extraction Or Liquid Replacement (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Manufacture And Refinement Of Metals (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明はネプツニウムの分離方法に関する。より詳し
くは、本発明は、ジ−イソデシルリン酸、ジ−２エチル
ヘキシルリン酸等の酸性リン酸エステル系抽出剤を使用
するネプツニウムの抽出分離方法に関する。The present invention relates to a method for separating neptunium. More specifically, the present invention relates to a method for extracting and separating neptunium using an acidic phosphoric acid ester-based extractant such as di-isodecylphosphoric acid and di-2ethylhexylphosphoric acid.
（従来の技術） ネプツニウムは、原子力発電によって発生する使用済
核燃料の中に比較的多く含まれる元素で、使用済核燃料
からウランやプルトニウムを抽出する再処理工程の中
で、その回収がネプツニウムを有効利用するという立場
から検討されてきた。最近では、放射性廃棄物への処理
処分の観点から、ネプツニウムは、危険性の高い元素と
見なされるようになり、使用済核燃料溶液や高レベル再
処理廃液などの放射性溶液から、より効率的にネプツニ
ウムを分離する方法を開発することが必要となってき
た。(Prior art) Neptunium is an element that is contained in a relatively large amount in spent nuclear fuel generated by nuclear power generation, and its recovery is effective in the reprocessing process of extracting uranium and plutonium from spent nuclear fuel. It has been considered from the standpoint of using it. Recently, from the viewpoint of treatment and disposal of radioactive waste, neptunium has been regarded as a high-risk element, and neptunium can be more efficiently extracted from radioactive solutions such as spent nuclear fuel solution and high-level reprocessing waste liquid. It has become necessary to develop methods to separate
分離方法としては、多量の放射性溶液から連続的にネ
プツニウムを分離することができることから、有機溶媒
を使用する抽出法が優れていると考えられるが、従来の
抽出では、一般に溶液中でＶ価イオン形としてはNpO2 +
の状態で存在するネプツニウムを、酸化剤、又は還元剤
を使用してVI価（NpO2 2+）、又はIV価（Np4+）に予め調
整した後に、有機溶媒で抽出する。この方法の欠点は、
ネプツニウムの分離回収率を高めるために、溶液中の酸
化・還元状態を如何に保持するかと言う問題、及び酸化
剤や還元剤を使用すると言う操作の複雑さとこれらの試
薬を含む新たな廃液の発生と言う問題である。As the separation method, it is possible to continuously separate neptunium from a large amount of radioactive solution, so it is considered that the extraction method using an organic solvent is superior. As a form, NpO 2 +
Neptunium present in the state, oxidizing agents, or valence VI using a reducing agent (NpO 2 2+), or after pre-adjusted to IV value (Np 4+), extracted with an organic solvent. The disadvantage of this method is
The problem of how to maintain the oxidation / reduction state in the solution in order to increase the separation recovery of neptunium, the operation complexity of using an oxidizing agent and a reducing agent, and the generation of new waste liquid containing these reagents Is a problem.
（発明が解決せんとする問題点） これらの欠点を無くすためには、Ｖ価（NpO2 +）のネ
プツニウムを直接抽出できる有機溶媒を使用することが
最も望ましい。このような要求を満たすネプツニウムの
分離法として、ジ−イソデシルリン酸を使用するネプツ
ニウム抽出法が発明されている（特開昭61−30799号）
が、この方法には、約２規定を限度として酸の濃度が大
きくなるに従い抽出速度が小さくなると言う改良すべき
点がある。(Problems to be Solved by the Invention) In order to eliminate these drawbacks, it is most desirable to use an organic solvent capable of directly extracting Vept (NpO 2 + ) Neptunium. As a method for separating neptunium satisfying such requirements, a neptunium extraction method using di-isodecylphosphoric acid has been invented (Japanese Patent Laid-Open No. 61-30799).
However, there is a point to be improved in this method in that the extraction rate becomes smaller as the acid concentration becomes higher within a limit of about 2 N.
本発明の目的は、このような問題点を解決して抽出速
度を大きくしたネプツニウムの分離方法を提供すること
である。An object of the present invention is to provide a method for separating neptunium in which such problems are solved and the extraction speed is increased.
（問題点を解決するための手段） 本願発明者は、この問題を解決せんとして鋭意研究の
結果、ジ−イソデシルリン酸を使用してＶ価（NpO2 +）
のネプツニウムを抽出分離する際、過酸化水素を添加す
るとネプツニウムの抽出速度が増大することを発見し、
本願発明に到達した。(Means for Solving the Problems) The inventors of the present application have conducted diligent research as a solution to this problem, and as a result, di-isodecylphosphoric acid was used to obtain a V value (NpO 2 + )
It was discovered that the extraction rate of neptunium increases when hydrogen peroxide is added during the extraction and separation of neptunium from
The present invention has been reached.
また、過酸化水素を添加するときは、ジ−２エチルヘ
キシル酸等の他の酸性リン酸エステル系抽出剤によるＶ
価（NpO2 +）のネプツニウムを抽出においても、抽出速
度が大きくなり、これまで高い酸濃度溶液系で使用不可
能であった抽出剤もＶ価（NpO2 +）のネプツニウムの抽
出分離に使用することが可能になる。Also, when hydrogen peroxide is added, V with other acidic phosphate ester-based extractants such as di-2 ethylhexyl acid is added.
The extraction rate is high even when extracting Neptunium with a valency (NpO 2 + ), and an extractant that was previously unusable in a high acid concentration solution system is also used for the extraction and separation of Neptunium with a V value (NpO 2 + ). It becomes possible to do.
過酸化水素を添加することの意味は、ネプツニウムを
Ｖ価（NpO2 +）からIV価（Np4+）に還元することである
が、0.5規定程度の酸濃度の低い水溶液では、還元反応
はほとんど進行せず、酸性リン酸エステル系抽出剤が共
存するという条件が加わって始めて、この還元反応が進
行するものである。The meaning of adding hydrogen peroxide is to reduce neptunium from V value (NpO 2 + ) to IV value (Np 4+ ), but in an aqueous solution with a low acid concentration of about 0.5 N, the reduction reaction is The reduction reaction proceeds only after the condition that the acidic phosphate ester-based extractant coexists with little progress.
（実施例） 次に、実施例によって本発明をさらに具体的に説明す
る。但し、本発明は実施例によって限定されるものでは
ない。(Examples) Next, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to the examples.
実施例 共栓付試験管に、硝酸、及びＶ価に調整したネプツニ
ウム−237溶液を入れた後、過酸化水素水溶液、又は水
を加えて全量を2mlとした。これに0.5Mジ−イソデシル
リン酸＋ｎ−ドデカン、又は0.5Mジ−２エチルヘキシル
リン酸＋ｎ−ドデカンの有機溶媒を2ml加えて、所定時
間振とうした。遠心分離法によって、有機相と水相を分
離した後、両相から1mlずつ分取し、放射能測定試料と
した。ネプツニウム−237の29KeVのガンマ線をGe検出器
により測定して、ネプツニウムの分配比を求めた。Example Nitric acid and a Neptunium-237 solution adjusted to a V value were placed in a test tube with a ground stopper, and an aqueous solution of hydrogen peroxide or water was added to make a total volume of 2 ml. 2 ml of an organic solvent of 0.5M di-isodecylphosphoric acid + n-dodecane or 0.5M di-2ethylhexylphosphoric acid + n-dodecane was added thereto, and shaken for a predetermined time. After the organic phase and the aqueous phase were separated by the centrifugation method, 1 ml of each of the phases was separated and used as a radioactivity measurement sample. The 29 KeV gamma ray of Neptunium-237 was measured by a Ge detector to determine the distribution ratio of Neptunium.
なお、ここで使用したネプツニウムＶ価の調整液は、
塩酸ヒドロキシアミン、及びスルファミン酸第１鉄を加
えてIV価に還元した溶液から、0.5Mテノイルトリフルオ
ロアセトン＋キシレン溶液でネプツニウムを抽出した
後、10M硝酸で逆抽出し、その後水で希釈し、0.5M硝酸
溶液としてから、温浴加熱を１時間行った後、0.1M硝酸
溶液としたものである。The neptunium V value adjusting solution used here is
Hydroxyamine hydrochloride and ferrous sulfamate were added to reduce the IV value of the solution to extract neptunium with 0.5M thenoyltrifluoroacetone + xylene solution, then back-extracted with 10M nitric acid, and then diluted with water, A 0.5M nitric acid solution was prepared, and after heating in a warm bath for 1 hour, a 0.1M nitric acid solution was prepared.
結果は第１図に示した。図において、横軸は振とうを
行った時間（分）で、縦軸はネプツニウムの分配比であ
る。いずれも0.5M硝酸溶液からのＶ価（NpO2 +）の抽出
であり、（イ）及び（ハ）は0.5Mジ−イソデシルリン酸
＋ｎ−ドデカンに依るもの、（ロ）および（ニ）は0.5M
−２エチルヘキシルリン酸＋ｎ−ドデカンに依るもの
で、（イ）及び（ロ）は過酸化水素を0.4Mの濃度で含
み、（ハ）及び（ニ）は過酸化水素を含まない。この図
から明らかなように、いずれの抽出剤に対しても、過酸
化水素の共存により、Ｖ価（NpO2 +）の抽出の速度が増
大する。The results are shown in Fig. 1. In the figure, the horizontal axis represents the shaking time (minutes), and the vertical axis represents the distribution ratio of neptunium. Both are extractions of V value (NpO 2 + ) from a 0.5 M nitric acid solution, (a) and (c) depend on 0.5 M di-isodecylphosphoric acid + n-dodecane, and (b) and (d) are 0.5. M
-2 ethylhexyl phosphoric acid + n-dodecane, wherein (a) and (b) contain hydrogen peroxide at a concentration of 0.4M, and (c) and (d) do not contain hydrogen peroxide. As is clear from this figure, the coexistence of hydrogen peroxide increases the extraction rate of V value (NpO 2 + ) for any of the extractants.
第１図は、本発明の実施例における結果を示すグラフで
ある。FIG. 1 is a graph showing the results in the examples of the present invention.
Claims (1)
シルリン酸等の酸性リン酸エステル系抽出剤を使用する
ネプツニウムの抽出分離法において、抽出系に過酸化水
素を共存させることを特徴とするネプツニウムの分離方
法1. A method for extracting and separating neptunium using an acidic phosphoric acid ester-based extractant such as di-isodecylphosphoric acid or di-2ethylhexylphosphoric acid, wherein hydrogen peroxide is allowed to coexist in the extraction system. Separation method
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62048754A JP2561831B2 (en) | 1987-03-05 | 1987-03-05 | Separation method of neptunium |
| FR8802788A FR2611689B1 (en) | 1987-03-05 | 1988-03-04 | PROCESS FOR SEPARATING NEPTUNIUM |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62048754A JP2561831B2 (en) | 1987-03-05 | 1987-03-05 | Separation method of neptunium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63218510A JPS63218510A (en) | 1988-09-12 |
| JP2561831B2 true JP2561831B2 (en) | 1996-12-11 |
Family
ID=12812070
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62048754A Expired - Fee Related JP2561831B2 (en) | 1987-03-05 | 1987-03-05 | Separation method of neptunium |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2561831B2 (en) |
| FR (1) | FR2611689B1 (en) |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2907628A (en) * | 1949-06-22 | 1959-10-06 | Lyle R Dawson | Neptunium solvent extraction process |
| US2847276A (en) * | 1955-04-15 | 1958-08-12 | John P Butler | Solvent extraction of neptunium |
| US3004823A (en) * | 1959-07-15 | 1961-10-17 | Donald F Peppard | Method of separating neptunium by liquid-liquid extraction |
| US4341743A (en) * | 1980-12-29 | 1982-07-27 | E. I. Du Pont De Nemours And Company | Simultaneous oxidation and extraction of vanadium from wet-process phosphoric acid |
| DE3332954A1 (en) * | 1983-09-13 | 1985-03-28 | Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe | METHOD FOR SEPARATING NEPTUNIUM FROM AN ORGANIC PHASE IN THE REPROCESSING OF IRRADIATED NUCLEAR FUELS AND / OR IRON MATERIALS |
| JPS6130799A (en) * | 1984-07-24 | 1986-02-13 | 日本原子力研究所 | Method of separating neptunium |
-
1987
- 1987-03-05 JP JP62048754A patent/JP2561831B2/en not_active Expired - Fee Related
-
1988
- 1988-03-04 FR FR8802788A patent/FR2611689B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63218510A (en) | 1988-09-12 |
| FR2611689A1 (en) | 1988-09-09 |
| FR2611689B1 (en) | 1991-11-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |