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Title: Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent

Abstract

This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation atmore » low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.« less

Authors:
Publication Date:
Research Org.:
ORNL Oak Ridge National Laboratory (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
814610
Report Number(s):
ORNL/TM-2002/190
TRN: US200318%%87
DOE Contract Number:  
AC05-00OR22725
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 8 Oct 2002
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; ANIONS; CALIXARENES; CESIUM; COALESCENCE; FLOWSHEETS; PHYSICAL PROPERTIES; PROCESS SOLUTIONS; SCRUBBING; SOLUBILITY; SOLVENT EXTRACTION; SOLVENTS; TEMPERATURE DEPENDENCE; VISCOSITY; WASTES

Citation Formats

Delmau, L H. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent. United States: N. p., 2002. Web. doi:10.2172/814610.
Delmau, L H. Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent. United States. doi:10.2172/814610.
Delmau, L H. Tue . "Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent". United States. doi:10.2172/814610. https://www.osti.gov/servlets/purl/814610.
@article{osti_814610,
title = {Caustic-Side Solvent Extraction: Chemical and Physical Properties of the Optimized Solvent},
author = {Delmau, L H},
abstractNote = {This work was undertaken to optimize the solvent used in the Caustic Side Solvent Extraction (CSSX) process and to measure key chemical and physical properties related to its performance in the removal of cesium from the alkaline high-level salt waste stored in tanks at the Savannah River Site. The need to adjust the solvent composition arose from the prior discovery that the previous baseline solvent was supersaturated with respect to the calixarene extractant. The following solvent-component concentrations in Isopar{reg_sign} L diluent are recommended: 0.007 M calix[4]arene-bis(tert-octylbenzo-crown-6) (BOBCalixC6) extractant, 0.75 M 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-sec-butylphenoxy)-2-propanol (Cs-7SB) phase modifier, and 0.003 M tri-n-octylamine (TOA) stripping aid. Criteria for this selection included BOBCalixC6 solubility, batch cesium distribution ratios (D{sub Cs}), calculated flowsheet robustness, third-phase formation, coalescence rate (dispersion numbers), and solvent density. Although minor compromises within acceptable limits were made in flowsheet robustness and solvent density, significant benefits were gained in lower risk of third-phase formation and lower solvent cost. Data are also reported for the optimized solvent regarding the temperature dependence of D{sub Cs} in extraction, scrubbing, and stripping (ESS); ESS performance on recycle; partitioning of BOBCalixC6, Cs-7SB, and TOA to aqueous process solutions; partitioning of organic anions; distribution of metals; solvent phase separation at low temperatures; solvent stability to elevated temperatures; and solvent density and viscosity. Overall, the technical risk of the CSSX process has been reduced by resolving previously identified issues and raising no new issues.},
doi = {10.2172/814610},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2002},
month = {10}
}

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