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Calixarene crown ether solvent composition and use thereof for extraction of cesium from alkaline waste solutions

United States Patent

January 16, 2001
View the Complete Patent at the US Patent & Trademark Office
Oak Ridge National Laboratory - Visit the Partnerships Directorate Website
A solvent composition and corresponding method for extracting cesium (Cs) from aqueous neutral and alkaline solutions containing Cs and perhaps other competing metal ions is described. The method entails contacting an aqueous Cs-containing solution with a solvent consisting of a specific class of lipophilic calix[4]arene-crown ether extractants dissolved in a hydrocarbon-based diluent containing a specific class of alkyl-aromatic ether alcohols as modifiers. The cesium values are subsequently recovered from the extractant, and the solvent subsequently recycled, by contacting the Cs-containing organic solution with an aqueous stripping solution. This combined extraction and stripping method is especially useful as a process for removal of the radionuclide cesium-137 from highly alkaline waste solutions which are also very concentrated in sodium and potassium. No pre-treatment of the waste solution is necessary, and the cesium can be recovered using a safe and inexpensive stripping process using water, dilute (millimolar) acid solutions, or dilute (millimolar) salt solutions. An important application for this invention would be treatment of alkaline nuclear tank wastes. Alternatively, the invention could be applied to decontamination of acidic reprocessing wastes containing cesium-137.
Moyer; Bruce A. (Oak Ridge, TN), Sachleben; Richard A. (Knoxville, TN), Bonnesen; Peter V. (Knoxville, TN), Presley; Derek J. (Ooltewah, TN)
Lockheed Martin Energy Research Corporation (Oak Ridge, TN)
09/ 146,800
September 3, 1998
STATEMENT AS TO RIGHTS TO INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT The U.S. Government has rights in this invention pursuant to contract number DE-AC05-96OR22464 between the United States Department of Energy and Lockheed Martin Energy Research Corporation.