Combined Extraction of Cesium and Strontium from Alkaline Nitrate Solutions

Abstract

The combined extraction of cesium and strontium from caustic wastes can be achieved by adding a crown ether and a carboxylic acid to the Caustic‐Side Solvent Extraction (CSSX) solvent. The ligand 4,4′(5′)‐di(tert‐butyl)cyclohexano‐18‐crown‐6 and one of four different carboxylic acids were combined with the components of the CSSX solvent optimized for the extraction of cesium, allowing for the simultaneous extraction of cesium and strontium from alkaline nitrate media simulating alkaline high level wastes present at the U.S. Department of Energy Savannah River Site. Extraction and stripping experiments were conducted independently and exhibited adequate results for mimicking waste simulant processing through batch contacts. The promising results of these batch tests showed that the system could reasonably be tested on actual waste.

Keywords:

• Cesium and strontium extraction
• crown ethers
• caustic‐side solvent extraction solvent
• alkaline nitrate media

Acknowledgments

This research was sponsored by the Environmental Management Science Program of the Offices of Science and Environmental Management, U.S. Department of Energy, under contract number DE‐AC05‐00OR22725 with Oak Ridge National Laboratory, managed by UT‐Battelle, LLC.