Claims
- 1. A process for removing radioactive ruthenium from an aqueous solution, comprising oxidizing ruthenium in said aqueous solution to ruthenium tetroxide, extracting the resulting ruthenium tetroxide with a halogen-free aliphatic or alicyclic hydrocarbon solvent, allowing the ruthenium tetroxide to be reduced in the solvent, and separating the precipitated solid ruthenium dioxide.
- 2. The process as claimed in claim 1, wherein when ruthenium in the aqueous solution is a stable nitrosyl complex, the complex is converted into an easily extractable ruthenium compound by the addition of hydrogen peroxide and heating before extraction.
- 3. The process as claimed in claim 1, wherein tetravalent cerium is used as an oxidizing agent.
- 4. The process as claimed in claim 3, wherein tetravalent cerium is present in an amount of about 1.5 to about 2 equivelants to ruthenium.
- 5. The process as claimed in claim 1, wherein the oxidation of the ruthenium in the aqueous solution is carried out by electrolytic oxidation.
- 6. The process as claimed in claim 1, wherein a paraffinic hydrocarbon having about 11 to about 18 carbon atoms is used as the extraction solvent.
- 7. The process as claimed in claim 6, wherein the extraction solvent is n-dodecane.
- 8. The process as claimed in claim 1, wherein the liquid paraffin is used as the extraction solvent.
- 9. The process as claimed in claim 1, wherein after the extraction, the extraction solvent is heated or allowed to stand.
- 10. The process as claimed in claim 1, wherein the precipitated ruthenium dioxide is separated by filtration or centrifuging.
- 11. The process as claimed in claim 10, wherein the filtration is carried out using a filtering material or filtering aid composed of cellulose fibers.
- 12. The process as claimed in claim 1, wherein during the steps of oxidizing and extracting ruthenium, a nitric acid concentration in said aqueous solution is about 3M.
- 13. The process as claimed in claim 1, wherein during the steps of oxidizing and extracting ruthenium, a nitric acid concentration in said aqueous solution is about 6M or less.
- 14. The process as claimed in claim 1, wherein extracting the ruthenium tetroxide is conducted at a temperature of 50.degree. to 60.degree. C.
- 15. The process as claimed in claim 1, wherein extracting the ruthenium tetroxide is conducted at room temperature.
- 16. The process as claimed in claim 1, wherein extracting the ruthenium tetroxide is conducted at a temperature of 60.degree. C. to 80.degree. C. when ruthenium in the aqueous solution is in the form of a stable nitrosyl complex.
Priority Claims (1)
Number |
Date |
Country |
Kind |
61-239199 |
Oct 1986 |
JPX |
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CROSS-REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part application of U.S. Ser. No. 106,355, filed Oct. 9, 1987, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4105442 |
Fieberg et al. |
Aug 1978 |
|
4282112 |
Fitoussi et al. |
Aug 1981 |
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Foreign Referenced Citations (2)
Number |
Date |
Country |
0014629 |
Aug 1980 |
EPX |
2701709 |
Jul 1978 |
DEX |
Non-Patent Literature Citations (4)
Entry |
Analytica Chimica Acta, 183 (1986), Kenji Motojima et al. [Determination of Traces of Ruthenium by Addition of Cerium(IV) and Atomic Absorption Spectrometry], pp. 217-223. |
Journal of Radioanalytical Chemistry, vol. 6 (1970), Y. Koda [Determination of Radioruthenium Using a Polyethylene Film], pp. 345-357. |
Journal of Chemical Technique and Biotechnology, vol. 29, No. 4 (1979), pp. 210-224. |
Journal of Inorganic and Nuclear Chemistry, vol. 43, pp. 385-390. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
106355 |
Oct 1987 |
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