skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation

Abstract

The ingenious combination of lactate and diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) as an aqueous actinide-complexing medium forms the basis of the successful separation of americium and curium from lanthanides known as the TALSPEAK process. While numerous reports in the prior literature have focused on the optimization of this solvent extraction system, considerably less attention has been devoted to the understanding of the basic thermodynamic features of the complex fluids responsible for the separation. The available thermochemical information of both lactate and DTPA protonation and metal complexation reactions are representative of the behavior of these ions under idealized conditions. Our previous studies of medium effects on lactate protonation suggest that significant departures from the speciation predicted based on reported thermodynamic values should be expected in the TALSPEAK aqueous environment. Thermodynamic parameters describing the separation chemistry of this process thus require further examination at conditions significantly removed from conventional ideal systems commonly employed in fundamental solution chemistry. Such thermodynamic characterization is the key to predictive modelling of TALSPEAK. Improved understanding will, in principle, allow process technologists to more efficiently respond to off-normal conditions during large scale process operation. In this report, the results of calorimetric and potentiometric investigations of the effects of aqueous electrolytesmore » on the thermodynamic parameters for lactate protonation and lactate complexation of americium and neodymium will be presented. Studies on the lactate protonation equilibrium will clearly illustrate distinct thermodynamic variations between strong electrolyte aqueous systems and buffered lactate environment.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Idaho National Laboratory (INL)
Sponsoring Org.:
DOE - NE
OSTI Identifier:
971371
Report Number(s):
INL/CON-09-16421
TRN: US1001172
DOE Contract Number:  
DE-AC07-05ID14517
Resource Type:
Conference
Resource Relation:
Conference: Actinides 2009,San Francisco,07/12/2009,07/17/2009
Country of Publication:
United States
Language:
English
Subject:
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY; ACTINIDES; AMERICIUM; CHEMISTRY; CURIUM; ELECTROLYTES; LACTATES; NEODYMIUM; OPTIMIZATION; RARE EARTHS; SOLVENT EXTRACTION; TALSPEAK PROCESS; THERMODYNAMICS; actinides; lactate; lanthanides; TALSPEAK; thermodynamics

Citation Formats

Peter R Zalupski, Leigh R Martin, Ken Nash, Yoshinobu Nakamura, and Masahiko Yamamoto. Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation. United States: N. p., 2009. Web.
Peter R Zalupski, Leigh R Martin, Ken Nash, Yoshinobu Nakamura, & Masahiko Yamamoto. Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation. United States.
Peter R Zalupski, Leigh R Martin, Ken Nash, Yoshinobu Nakamura, and Masahiko Yamamoto. Wed . "Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation". United States. https://www.osti.gov/servlets/purl/971371.
@article{osti_971371,
title = {Toward understanding the thermodynamics of TALSPEAK process. Medium effects on actinide complexation},
author = {Peter R Zalupski and Leigh R Martin and Ken Nash and Yoshinobu Nakamura and Masahiko Yamamoto},
abstractNote = {The ingenious combination of lactate and diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) as an aqueous actinide-complexing medium forms the basis of the successful separation of americium and curium from lanthanides known as the TALSPEAK process. While numerous reports in the prior literature have focused on the optimization of this solvent extraction system, considerably less attention has been devoted to the understanding of the basic thermodynamic features of the complex fluids responsible for the separation. The available thermochemical information of both lactate and DTPA protonation and metal complexation reactions are representative of the behavior of these ions under idealized conditions. Our previous studies of medium effects on lactate protonation suggest that significant departures from the speciation predicted based on reported thermodynamic values should be expected in the TALSPEAK aqueous environment. Thermodynamic parameters describing the separation chemistry of this process thus require further examination at conditions significantly removed from conventional ideal systems commonly employed in fundamental solution chemistry. Such thermodynamic characterization is the key to predictive modelling of TALSPEAK. Improved understanding will, in principle, allow process technologists to more efficiently respond to off-normal conditions during large scale process operation. In this report, the results of calorimetric and potentiometric investigations of the effects of aqueous electrolytes on the thermodynamic parameters for lactate protonation and lactate complexation of americium and neodymium will be presented. Studies on the lactate protonation equilibrium will clearly illustrate distinct thermodynamic variations between strong electrolyte aqueous systems and buffered lactate environment.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2009},
month = {7}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: