Award Date

December 2017

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry and Biochemistry

First Committee Member

David Hatchett

Second Committee Member

Spencer Steinberg

Third Committee Member

Dong Chan Lee

Fourth Committee Member

Jacimaria Batista

Number of Pages

67

Abstract

Rare-earth elements include the lanthanide series in the periodic table with the addition of scandium and yttrium. China produces approximately 95% of the world’s rare-earths supply and is the largest consumer of the world’s rare earth supply. Domestic production of rare-earth metals is a priority in the US. The domestic demand for rare-earth elements is largely based on their use in electronic devices, catalytic converters, and more importantly defense applications. Therefore, China’s monopoly of rare-earth elements is viewed as a threat to national security. Although capital investments have resulted in an increase in domestic mining and refining of rare-earth materials, full scale production will take time. Alternatively, new methods for the reclamation of rare-earth materials could reduce the dependence on imported materials, as well as reduce electronic wastes in landfills. In this thesis, a path for the electrochemical reclamation of rare-earth materials is explored. Specifically, the dissolution of samarium carbonate and europium carbonate are examined in ionic liquid containing the acid N,N-bis(trifluoromethylsulfonyl)imide, HTf2N. The use of carbonate derivatives facilitates the dissolution of the rare-earth species through the formation of carbonic acid. The carbonic acid can then be purged through a decomposition reaction that produces water and carbon dioxide. The dissolution and coordination of the lanthanide with bis(trifluoromethylsulfonyl)imide anion, Tf2N, is evaluated using a spectroscopic method (UV-Vis). The electrochemistry of samarium and europium is examined in the ionic liquid and the studies demonstrate that electrochemical deposition of samarium and europium species occur. SEM/EDX analysis of the deposit on a grafoil electrode confirms the electrochemical reclamation of samarium and europium metal.

Keywords

Electrochemistry; Ionic Liquid; Lanthanides; Separations

Disciplines

Analytical Chemistry | Inorganic Chemistry | Physical Chemistry

Language

English


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