Search International and National Patent Collections

1. (WO1999012878) SOLVENT AND PROCESS FOR EXTRACTING CESIUM FROM ALKALINE WASTE SOLUTIONS

Pub. No.:    WO/1999/012878    International Application No.:    PCT/US1998/018316
Publication Date: Mar 18, 1999 International Filing Date: Sep 3, 1998
IPC: C22B 3/26
C22B 26/10
G21F 9/12
Applicants: LOCKHEED MARTIN ENERGY RESEARCH CORPORATION
Inventors: MOYER, Bruce, A.
SACHLEBEN, Richard, A.
BONNESEN, Peter, V.
PRESLEY, Derek, J.
Title: SOLVENT AND PROCESS FOR EXTRACTING CESIUM FROM ALKALINE WASTE SOLUTIONS
Abstract:
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. 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.