High Temperature Electrochemistry IV: Session IV
Sponsored by: TMS Extraction and Processing Division, TMS: Nuclear Materials Committee, TMS: Hydrometallurgy and Electrometallurgy Committee
Program Organizers: Prabhat Tripathy, Batelle Energy Alliance (Idaho National Laboratory); Guy Fredrickson, Idaho National Laboratory
Wednesday 8:30 AM
March 17, 2021
Room: RM 40
Location: TMS2021 Virtual
Session Chair: Guy Fredrickson, Idaho National Laboratory
8:30 AM
Interaction between Solute Species and Metallic Alloying Elements in Molten Chloride Systems: William Phillips1; Ruchi Gakhar1; 1Idaho National Laboratory
In the context of a salt-fueled molten salt reactor (MSR), understanding the chemistry of the lanthanide fission products and their interaction with structural alloys is of importance to be able to adequately describe the corrosion mechanisms that take place in the complex and constantly evolving environment of a MSR. Several of the lanthanide elements are able to form salt-soluble stable chlorides in both the 2+ and 3+ oxidation states, most notably Eu, Sm, and Yb. Europium is of particular interest due to the relatively positive reduction potential of the Eu3+ + e= → Eu2+ half-cell reaction with regards to a number of alloying elements in molten chloride systems. As such, this work investigates the interaction of lanthanide species, primarily Eu3+, and various metallic elements via electronic absorption spectroscopy. This work was supported through the INL Laboratory Directed Research & Development (LDRD) Program under DOE Idaho Operations Office Contract DE-AC07-05ID14517.
9:00 AM
Effect of Hydroxide and Oxide Impurities in Electrochemical Processes Using Molten LiCl and CaCl2: Mario Alberto Gonzalez1; Emma Faulkner1; Michael Simpson1; 1University of Utah
Molten chloride salts are known to be highly hygroscopic, and thus require dehydration prior to their use as an electrolyte in high temperature electrochemical processes. Thermal dehydration is often used, but incomplete water removal at lower temperatures can result in hydrolysis to form oxides or hydroxides at the higher temperatures required to melt the salt. In this paper, dehydration of LiCl and CaCl2 will be considered. These salts have been used widely for reduction and electrorefining of actinides. Cyclic voltammetry shows that thermal dehydration of LiCl leads to formation of LiOH, while thermal dehydration of CaCl2 leads to formation of CaO. The effects of these impurities on various high temperature electrochemical processes will be discussed.