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Title: A Physicochemical Method for Separating Rare Earths: Addressing an Impending Shortfall

Abstract

There are currently zero operating suppliers of critical rare earth elements La–Lu, Sc, Y (REs), in the western hemisphere. REs are critical materials due to their importance in clean energy and defense applications, including permanent magnets in wind turbines and phosphors in energy efficient lighting. It is not economically viable to produce pure REs in the U.S. given current separations technology. REs production is dominated by suppliers in the People’s Republic of China (PRC) because of their capacity in liquid­liquid solvent extraction (SX) used to purify mixtures. Weak environmental regulations in the PRC also contribute to a competitive advantage. SX is a cost, time, solvent and waste intensive process but is highly optimized and scalable. The low efficiency of SX derives from the small thermodynamic differences in solvation enthalpy between the RE3+ cations. To foster stable domestic RE production there is a critical need for fundamentally new REs chemistry that contributes to disruptive technologies in RE separations. The overall goal of this project was to develop new thermodynamic bases, and apply them, for the solution separation of rare earth metals. We have developed the chemistry of rare earth metals: La–Lu, Sc and Y, with redox active ligands. Our hypothesis formore » the project was that electron­hole coupling in complexes of certain lanthanide metals with redox active ligands can be used to manifest chemical distinctiveness and affect separations. We also developed separations based on unique solution equilibria from tailored ligands.« less

Authors:
ORCiD logo [1]
  1. Univ. of Pennsylvania, Philadelphia, PA (United States)
Publication Date:
Research Org.:
The Trustees of the University of Pennsylvania, Philadelphia, PA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1346741
Report Number(s):
DOE-UPENN-6518-2
DOE Contract Number:
SC0006518
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; lanthanides; rare earth metals; separations chemistry

Citation Formats

Schelter, Eric. A Physicochemical Method for Separating Rare Earths: Addressing an Impending Shortfall. United States: N. p., 2017. Web. doi:10.2172/1346741.
Schelter, Eric. A Physicochemical Method for Separating Rare Earths: Addressing an Impending Shortfall. United States. doi:10.2172/1346741.
Schelter, Eric. Tue . "A Physicochemical Method for Separating Rare Earths: Addressing an Impending Shortfall". United States. doi:10.2172/1346741. https://www.osti.gov/servlets/purl/1346741.
@article{osti_1346741,
title = {A Physicochemical Method for Separating Rare Earths: Addressing an Impending Shortfall},
author = {Schelter, Eric},
abstractNote = {There are currently zero operating suppliers of critical rare earth elements La–Lu, Sc, Y (REs), in the western hemisphere. REs are critical materials due to their importance in clean energy and defense applications, including permanent magnets in wind turbines and phosphors in energy efficient lighting. It is not economically viable to produce pure REs in the U.S. given current separations technology. REs production is dominated by suppliers in the People’s Republic of China (PRC) because of their capacity in liquid­liquid solvent extraction (SX) used to purify mixtures. Weak environmental regulations in the PRC also contribute to a competitive advantage. SX is a cost, time, solvent and waste intensive process but is highly optimized and scalable. The low efficiency of SX derives from the small thermodynamic differences in solvation enthalpy between the RE3+ cations. To foster stable domestic RE production there is a critical need for fundamentally new REs chemistry that contributes to disruptive technologies in RE separations. The overall goal of this project was to develop new thermodynamic bases, and apply them, for the solution separation of rare earth metals. We have developed the chemistry of rare earth metals: La–Lu, Sc and Y, with redox active ligands. Our hypothesis for the project was that electron­hole coupling in complexes of certain lanthanide metals with redox active ligands can be used to manifest chemical distinctiveness and affect separations. We also developed separations based on unique solution equilibria from tailored ligands.},
doi = {10.2172/1346741},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 14 00:00:00 EDT 2017},
month = {Tue Mar 14 00:00:00 EDT 2017}
}

Technical Report:

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