Using solvent extraction to process nitrate anion exchange column effluents

Octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO), a new organophosphorous extractant, and a new centrifugal mixer-settler both recently developed at Argonne were evaluated for their potential use in the recovery of actinides from nitrate anion exchange column effluents. The performance of the extractant was evaluated by measuring the extraction coefficient values as a function of acid and salt concentration. Additional performance parameters include extraction coefficient behavior as a function of the total metal concentration in the organic phase, and comparison of different stripping and organic scrubbing techniques. A simulated effluent stream was used to evaluate the performance of the centrifugal mixer-settlers by comparing experimental and calculated interstage concentration profiles. Both the CMPO extractant and the centrifugal mixer-settlers have potential for processing nitrate column effluents, particularly if the stripping behavior can be improved. Details of the proposed process are presented in the flowsheet and contactor design analyses.. Authors: Yarbro, S L. DOE Contract: W-7405-ENG-36. Subjects: 050800 -- Nuclear Fuels-- Spent Fuels Reprocessing; 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 400105* -- Separation Procedures; ACTINIDES; CENTRIFUGES; CHEMICAL EFFLUENTS; CONCENTRATORS; DIAGRAMS; ELEMENTS; EXTRACTION APPARATUSES; EXTRACTION COLUMNS; FLOWSHEETS; ION EXCHANGE; LIQUID WASTES; METALS; MIXER-SETTLERS; NITRATES; NITROGEN COMPOUNDS; Nuclear Criticality Safety Program (NCSP); ORGANIC COMPOUNDS; ORGANIC PHOSPHORUS COMPOUNDS; ORG