JPH07218687A - Method for lithium recovery from waste salt - Google Patents
Method for lithium recovery from waste saltInfo
- Publication number
- JPH07218687A JPH07218687A JP1118394A JP1118394A JPH07218687A JP H07218687 A JPH07218687 A JP H07218687A JP 1118394 A JP1118394 A JP 1118394A JP 1118394 A JP1118394 A JP 1118394A JP H07218687 A JPH07218687 A JP H07218687A
- Authority
- JP
- Japan
- Prior art keywords
- cathode
- liquid
- electrolysis
- waste salt
- salt waste
- 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.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E30/00—Energy generation of nuclear origin
- Y02E30/30—Nuclear fission reactors
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
Landscapes
- Electrolytic Production Of Metals (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、使用済み核燃料の乾式
分離処理時に発生する塩廃棄物からのリチウム回収方法
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering lithium from salt waste generated during dry separation of spent nuclear fuel.
【０００２】[0002]
【従来の技術】この種の軽水炉での使用済み核燃料の再
処理時に発生する高レベル廃液は、乾式分離プロセスに
よって処理されることが確認されている。ここで、該乾
式分離プロセスでは、先ず、高レベル廃液を塩化物の形
態に転換した後に、その還元抽出工程において、 Cd(カ
ドミウム，以下、 Cd と呼ぶ) −Li(リチウム，以下、
Li と呼ぶ) 合金の Li を用いることで、塩化物中の超
ウラン元素を選択的に還元して合金内に取り込むように
するが、この際、該 Cd −Li 合金の Li は、 LiCl と
なって還元されない元素の塩化物となり、この結果、該
塩化物中には、LiCl,NaCl を主成分にして、その他に、
CsCl,RbCl,SrCl2, BaCl2,YCl3,EuCl3,SmCl3 等を夫々に
含む塩廃棄物が発生する。2. Description of the Related Art It has been confirmed that the high-level liquid waste generated during the reprocessing of spent nuclear fuel in a light water reactor of this type is processed by a dry separation process. Here, in the dry separation process, first, after converting the high-level waste liquid into a chloride form, in the reducing and extracting step thereof, Cd (cadmium, hereinafter, referred to as Cd) -Li (lithium, hereinafter,
The Li of the alloy) is used to selectively reduce the transuranium element in the chloride and incorporate it into the alloy.At this time, the Li of the Cd-Li alloy becomes LiCl. Becomes a chloride of an element that is not reduced, and as a result, in the chloride, LiCl and NaCl are the main components, and in addition,
Salt waste containing CsCl, RbCl, SrCl 2 , BaCl 2 , YCl 3 , EuCl 3 , SmCl 3 etc. is generated.
【０００３】而して、前記塩廃棄物には、90Sr，137Cs
等の前記超ウラン元素に比較して半減期は短いものの放
射能の強い核種を含んでいるために、これをガラス固化
等の手段で適正に処置した上で処分する必要がある。Therefore, the salt waste contains 90 Sr, 137 Cs.
Since it contains a radionuclide having a short half-life as compared with the above transuranic elements, it must be treated appropriately by means such as vitrification and then disposed.
【０００４】[0004]
【発明が解決しようとする課題】先に述べた如く、前記
塩廃棄物中には、その主成分として LiCl が多く含まれ
ており、該 Li については、これが非放射性であって必
ずしも廃棄処理する必要がなく、しかも、前記高レベル
廃液の処理，つまり、この場合，還元抽出工程に関して
有用であるのにも拘らず、塩廃棄物をそのままで処理す
る方法にあっては、結果的に、該塩廃棄物の内部に多く
含まれている LiCl についてもまた、ガラス固化による
処分に際して、何ら活用されることなしに無意義に破棄
されてしまうことになる。As described above, the salt waste contains a large amount of LiCl as its main component, and this Li is non-radioactive and is always discarded. In the process of treating the high-level waste liquid, which is not necessary and is useful for the reduction extraction step in this case, the method for treating salt waste as it is results in LiCl, which is abundantly contained in salt waste, will also be discarded insignificantly without being utilized at the time of disposal by vitrification.
【０００５】従って、本発明の目的とするところは、こ
のような実情に鑑み、高レベル廃液を乾式分離プロセス
で処理する場合、その Cd − Li 合金を用いた還元抽出
工程で発生する塩廃棄物の処理に際し、該塩廃棄物内に
包含される各強い放射性成分中から、主に Li 成分のみ
を分離して回収し、該回収された Li を還元抽出工程に
おいて再利用可能にするための新規な塩廃棄物からの L
i 回収方法を提供することである。Therefore, in view of the above situation, the object of the present invention is to treat salt waste generated in the reduction extraction process using the Cd-Li alloy when the high-level waste liquid is treated by the dry separation process. In the treatment of, the Li component is mainly separated from each of the strong radioactive components contained in the salt waste, and the recovered Li is reused in the reductive extraction process. L from fresh salt waste
i It is to provide a recovery method.
【０００６】[0006]
【課題を解決するための手段】前記目的を達成するため
に、本発明は、軽水炉使用済み核燃料のピューレックス
法による再処理時の高レベル廃液を乾式分離プロセスで
処理する場合、その還元抽出工程で発生する塩廃棄物か
ら Li を回収する方法において、塩廃棄物を液体 Cd カ
ソードによって電解処理し、該塩廃棄物内に包含される
強い放射性の各成分中から、主に Li 成分のみを分離し
て回収するようにしたことを特徴とするものである。In order to achieve the above-mentioned object, the present invention provides a reduction extraction step for treating a high-level waste liquid at the time of reprocessing the spent nuclear fuel of a light water reactor by the Purex method by a dry separation process. In the method of recovering Li from salt waste generated in the process, the salt waste is electrolyzed with a liquid Cd cathode, and only the Li component is mainly separated from each of the strongly radioactive components contained in the salt waste. It is characterized in that it is adapted to be collected.
【０００７】[0007]
【作用】ここで、前記塩廃棄物中には、先に述べた如
く、LiCl,NaCl を主成分とし、且つ CsCl,RbCl,SrCl2,B
aCl2,YCl3,EuCl3,SmCl3 等が夫々に含まれているが、こ
の場合、該塩廃棄物を液体 Cd カソードによって電解処
理すると、これらの各元素の内で、分解電圧，分極，原
子価，及びカソード金属との結合力の関係において、比
較的電析され易い Li 成分が Cd 合金中に高濃度で電析
分離されることになる。Here, in the salt waste, as described above, the main components are LiCl and NaCl, and CsCl, RbCl, SrCl 2 and B are added.
aCl 2 , YCl 3 , EuCl 3 , SmCl 3 etc. are contained in each of them, but in this case, when the salt waste is subjected to electrolytic treatment with a liquid Cd cathode, decomposition voltage, polarization, Due to the relationship between the valence and the bond strength with the cathode metal, the Li component, which is relatively easily electrodeposited, is electrodeposited and separated in the Cd alloy at a high concentration.
【０００８】そして、前記のようにして電析される Cd
合金中には、目的とする Li 成分の他にも、例えば、Na
, Sm の各成分等を含んでいるが、 Li 成分の濃度が極
めて高いために、該 Cd 成分中に Li 成分を溶かし込ん
で製造される Cd − Li 合金と適切な比率で混合させる
ことによって、これを所期通りに還元抽出工程で再利用
可能にし得る。なお、この場合、対極としてのアノード
には、黒鉛等の不溶性アノードを使用するのがよく、且
つその電解処理時に発生する塩素ガスについては、これ
を取り出すことにより、ここでの乾式分離プロセスにお
ける別の塩素化工程で、該塩素ガスについても同様に再
利用可能である。Then, Cd which is electrodeposited as described above
In the alloy, in addition to the target Li component, for example, Na
, Sm, etc., but since the Li component concentration is extremely high, by mixing the Cd component with the Cd-Li alloy produced by dissolving the Li component in the Cd component, the mixture is mixed at an appropriate ratio. It can be made reusable in the reducing extraction step as expected. In this case, it is preferable to use an insoluble anode such as graphite for the anode as the counter electrode, and chlorine gas generated during the electrolytic treatment is taken out to separate it in the dry separation process. In the chlorination step, the chlorine gas can be reused similarly.
【０００９】[0009]
【実施例】次に、本発明に係る塩廃棄物からの Li 回収
方法の各別の実施例につき、図１を参照して詳細に述べ
る。EXAMPLES Next, different examples of the method for recovering Li from salt waste according to the present invention will be described in detail with reference to FIG.
【００１０】図１は、実施例１乃至３の各電解試験に適
用される電解セルの概要を模式的に示す断面構成図であ
る。FIG. 1 is a schematic sectional view showing the outline of an electrolysis cell applied to each electrolysis test of Examples 1 to 3.
【００１１】実施例１ ここでは、電気炉を内蔵すると共に、水分濃度，酸素濃
度等を 1ppm 以下に維持したグローブボックス内に、図
１に示す電解セルを設置して電解試験を行なった。Example 1 Here, an electrolysis test was carried out by installing the electrolysis cell shown in FIG. 1 in a glove box in which an electric furnace was incorporated and the water concentration, oxygen concentration, etc. were maintained at 1 ppm or less.
【００１２】本実施例１の場合には、先ず最初に、内径
55mm からなるアルミナ製容器１１内に対し、ここでの
液体 Cd カソード１２として、カドミウムの 705g と、
被処理物である塩廃棄物を模擬することで、次の表１に
示す組成の液体状混合塩１３の 805g とを順次に封入し
た。In the case of the first embodiment, first of all, the inner diameter
In an alumina container 11 made of 55 mm, as the liquid Cd cathode 12 here, 705 g of cadmium and
By simulating the salt waste that is the object to be treated, 805 g of the liquid mixed salt 13 having the composition shown in the following Table 1 was sequentially enclosed.
【００１３】 [0013]
【００１４】又、一方で、前記液体 Cd カソード１２の
対極となるアノード１４として、底部に石英隔膜１５を
有する石英管１６内に配した 10mm φの黒鉛棒を、前記
液体Cd カソード１２から離して 60mm の高さで封入す
ると共に、これを電源の＋極に接続させた上で、該黒鉛
アノード１４で発生する塩素ガスが、液体 Cd カソード
１２と反応して電流効率が低下するのを避けるために、
該塩素ガスを外部に取り出し得るようにした。更に、前
記液体 Cd カソード１２中には、石英製の攪拌プロペラ
１７を封入して、外部からの該液体 Cd カソード１２の
攪拌を可能にさせ、且つムライトチューブで覆った Mo
線を該液体 Cd カソード１２のリード線１８にして電源
の−極に接続させた。なお、図中，１９は電解操作時の
温度計測のための熱電対を封入した石英製保護管であ
る。On the other hand, a graphite rod of 10 mmφ arranged in a quartz tube 16 having a quartz diaphragm 15 at the bottom is separated from the liquid Cd cathode 12 as an anode 14 serving as a counter electrode of the liquid Cd cathode 12. In order to prevent the chlorine gas generated in the graphite anode 14 from reacting with the liquid Cd cathode 12 and lowering the current efficiency while enclosing it at a height of 60 mm and connecting it to the + pole of the power supply. To
The chlorine gas can be taken out. Further, a stirring propeller 17 made of quartz is enclosed in the liquid Cd cathode 12 to enable external stirring of the liquid Cd cathode 12 and is covered with a mullite tube.
The wire was used as the lead wire 18 of the liquid Cd cathode 12 and was connected to the negative terminal of the power supply. In the figure, 19 is a quartz protective tube in which a thermocouple for temperature measurement during electrolysis is enclosed.
【００１５】次いで、本実施例１では、この場合の電解
条件として、電流 3A , カソード電流密度 0.13A/cm2，
電解温度 500℃，攪拌プロペラ回転速度 120rpm に夫々
設定して、電解時間 270min による電解試験を行なっ
た。Next, in Example 1, as electrolysis conditions in this case, a current of 3 A, a cathode current density of 0.13 A / cm 2 ,
The electrolysis temperature was set to 500 ° C and the rotation speed of the stirring propeller was set to 120 rpm, and an electrolysis test was conducted at an electrolysis time of 270 min.
【００１６】本電解試験の結果、その電流効率は、約 1
00% であり、電析金属中の各元素濃度は、前記表１に示
す夫々の値となって、特に Li 成分が塩化物中で43mol%
であるのに対し液体 Cd カソード１２中で電析金属中60
mol%に高濃度で電析されることが確認された。As a result of the electrolytic test, the current efficiency is about 1
The concentration of each element in the electrodeposited metal is the respective value shown in Table 1 above, and especially the Li component is 43 mol% in chloride.
However, in liquid Cd cathode 12 in electrodeposited metal 60
It was confirmed that it was electrodeposited at a high concentration of mol%.
【００１７】実施例２ 本実施例２の場合には、次表２に示す組成の混合塩１３
の組成で、電解温度を550℃とし、他の電解条件を先の
実施例１の場合と全く同様に設定して電解試験を行なっ
た。Example 2 In the case of Example 2, mixed salt 13 having the composition shown in Table 2 below was used.
An electrolysis test was conducted by setting the electrolysis temperature to 550 ° C., setting the other electrolysis conditions to be exactly the same as in the case of the above-mentioned Example 1, with the above composition.
【００１８】そして、この実施例２の場合には、本電解
試験の結果、塩化物中での Li 濃度26mol%が、電析金属
中で Li 濃度66mol%となり、特に Li 成分が液体 Cd カ
ソード１２中に高濃度で電析されることが確認された。In the case of Example 2, as a result of the electrolysis test, the Li concentration in the chloride was 26 mol%, and the Li concentration in the electrodeposited metal was 66 mol%. Particularly, the Li component was the liquid Cd cathode 12. It was confirmed that electrodeposition was carried out at a high concentration inside.
【００１９】 [0019]
【００２０】実施例３ 本実施例３の場合には、次表３に示す混合塩１３の組成
で、電解温度を 550℃とし、他の電解条件を先の実施例
１の場合と全く同様に設定して電解試験を行なった。Example 3 In the case of the present Example 3, the composition of the mixed salt 13 shown in the following Table 3 was used, the electrolysis temperature was 550 ° C., and the other electrolysis conditions were exactly the same as in the case of the above Example 1. The electrolysis test was performed after setting.
【００２１】ここでも、この実施例３の場合には、本電
解試験の結果、塩化物中での Li 濃度 13mol% が、電析
金属中で Li 濃度 30mol% となり、特に Li 成分が液体
Cdカソード１２中に高濃度で電析されることが確認さ
れた。Also in this Example 3, as a result of the electrolytic test, the Li concentration in the chloride was 13 mol% and the Li concentration was 30 mol% in the electrodeposited metal.
It was confirmed that the Cd cathode 12 was electrodeposited at a high concentration.
【００２２】 [0022]
【００２３】[0023]
【発明の効果】以上、各実施例によって詳述したよう
に、本発明方法によれば、軽水炉での使用済み核燃料の
ピューレックス法による再処理時の高レベル廃液を乾式
分離プロセスで処理する場合、その還元抽出工程で発生
する塩廃棄物から Li を回収する方法において、塩廃棄
物を液体 Cd カソードによって電解処理するようにした
から、該塩廃棄物内に包含される強い放射性の各成分中
から、主に Li 成分を Cd合金中に高濃度で容易に電析
分離させ得るものであり、且つこのようにして分離され
た Li 成分を再度，還元抽出工程に利用することで、該
還元抽出工程における Li の消費量を適切に低減できる
と共に、従来確認されている方法ではガラス固化処理に
よって廃棄されている Li を有効且つ効果的に活用し得
るという優れた特長がある。As described above in detail with reference to each embodiment, according to the method of the present invention, when the high-level waste liquid at the time of reprocessing the spent nuclear fuel in the light water reactor by the Purex method is treated by the dry separation process. In the method of recovering Li from the salt waste generated in the reduction and extraction step, the salt waste was electrolytically treated with a liquid Cd cathode, so that the strong radioactive components contained in the salt waste were Therefore, mainly the Li component can be easily electrodeposited and separated into a Cd alloy at a high concentration, and the Li component separated in this way can be reused in the reduction extraction process to reduce the extraction. It has the excellent features that the consumption of Li in the process can be appropriately reduced, and that the conventionally confirmed method can effectively and effectively utilize the Li that is discarded by vitrification treatment.
【図１】本発明の実施例１乃至３の各電解試験に適用さ
れる電解セルの概要を模式的に示す断面構成図である。FIG. 1 is a cross-sectional configuration diagram schematically showing the outline of an electrolysis cell applied to each electrolysis test of Examples 1 to 3 of the present invention.
１１ アルミナ製容器 １２ 液体 Cd カソード １３ 塩廃棄物を模擬した混合塩 １４ アノード（黒鉛棒） １５ 石英隔膜 １６ 石英管 １７ 石英製攪拌プロペラ １８ リード線 １９ 温度計測用の熱電対を封入した石英製保護管 11 Alumina Container 12 Liquid Cd Cathode 13 Mixed Salt Simulating Salt Waste 14 Anode (graphite rod) 15 Quartz diaphragm 16 Quartz tube 17 Quartz stirring propeller 18 Lead wire 19 Quartz protection enclosing thermocouple for temperature measurement tube
───────────────────────────────────────────────────── フロントページの続き (72)発明者 清水 隆文 茨城県那珂郡東海村石神外宿2600 住友金 属鉱山株式会社原子力事業部東海試験所内 (72)発明者 金井 俊治 東京都港区新橋５−11−３ 住友金属鉱山 株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Takafumi Shimizu Inventor Takafumi Shimizu 2600 Ishigami Sotojuku, Tokai-mura, Naka-gun, Ibaraki Sumitomo Kinzoku Mining Co., Ltd., Tokai Laboratory (72) Inventor Toshiharu Kanai 5-11-Shimbashi, Minato-ku, Tokyo 3 Sumitomo Metal Mining Co., Ltd.
Claims (1)
法による再処理時の高レベル廃液を乾式分離プロセスで
処理する場合、その還元抽出工程で発生する塩廃棄物か
らリチウムを回収する方法であって、 前記塩廃棄物を液体カドミウムカソードによって電解処
理し、該塩廃棄物内に包含される強い放射性成分中か
ら、主にリチウム成分のみを分離して回収することを特
徴とする塩廃棄物からのリチウム回収方法。1. A method for recovering lithium from salt waste generated in the reduction extraction step when a high-level waste liquid at the time of reprocessing spent fuel of a light water reactor by the Purex method is treated by a dry separation process, Lithium from salt waste, characterized in that the salt waste is electrolyzed with a liquid cadmium cathode, and mainly lithium component is separated and recovered from among strong radioactive components contained in the salt waste. Recovery method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1118394A JPH07218687A (en) | 1994-02-02 | 1994-02-02 | Method for lithium recovery from waste salt |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1118394A JPH07218687A (en) | 1994-02-02 | 1994-02-02 | Method for lithium recovery from waste salt |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07218687A true JPH07218687A (en) | 1995-08-18 |
Family
ID=11770962
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1118394A Pending JPH07218687A (en) | 1994-02-02 | 1994-02-02 | Method for lithium recovery from waste salt |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07218687A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100593790B1 (en) * | 2003-03-28 | 2006-07-03 | 한국원자력연구소 | Method for electrolytic reduction of oxide spent fuel in LiCl-Li2O, cathode electrode assembly for applying the method, and device having the cathode electrode |
-
1994
- 1994-02-02 JP JP1118394A patent/JPH07218687A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100593790B1 (en) * | 2003-03-28 | 2006-07-03 | 한국원자력연구소 | Method for electrolytic reduction of oxide spent fuel in LiCl-Li2O, cathode electrode assembly for applying the method, and device having the cathode electrode |
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