Solvent Extraction of Strontium from Nitric Acid Medium by Di-Tert-butyl Cyclohexano-18-crown-6 in N-Octanol: Extraction Behavior and Flowsheet Demonstration

Abstract

The extraction of strontium from nitric acid medium by di-tert-butyl cyclohexano-18-crown-6 (DtBuCH18C6) in n-octanol was studied. The thermodynamic parameters were determined under different acidities, and the extraction was found to be driven by exothermic enthalpy and opposed by unfavorable entropy. Based on the results from batch experiments, a strontium extraction flowsheet (10, 2, and 4 stages for extraction, scrubbing, and stripping, respectively) was designed and tested on an array of 10-mm centrifugal contactors to treat a simulated acidic High Level Liquid Waste (HLLW). Strontium was found to be well separated from the simulant, and a decontamination factor of ˜4000 was achieved. The results indicate that this process is promising in actual HLLW treatment.Supplementary materials are available for this article. Go to the publisher's online edition of Solvent Extraction and Ion Exchange to view the supplementary file.