Thermodynamic evaluation of LiCl-KCl-PuCl3 system

Abstract

The present study focuses on developing the phase diagram of LiCl-KCl-PuCl3 system based on the CALPHAD (CALculation of PHase Diagram) method. Sub-binary systems of LiCl-KCl, LiCl-PuCl3, and KCl-PuCl3 were developed first by optimizing the Gibbs energy parameters according to the experimental data from literature using the two-sublattice model. Then the enthalpy of mixing of the LiCl-KCl-PuCl3 system was estimated, to explore the ternary interactions, using an empirical correlation derived from the surrounded-ion model for the asymmetric salt system due to the scarcity of available data for the ternary system. Based on the phase diagram developed, the solubility of PuCl3 in the eutectic LiCl-KCl melt at different temperatures was obtained, as well as the Gibbs energy of formation of PuCl3 in the salt as a function of PuCl3 concentration. The present study extends the experimental data for dilutions to concentrated solutions for which no experimental data have been well reported.

Defect‐Rich Graphene Nanomesh Produced by Thermal Exfoliation of Metal–Organic Frameworks for the Oxygen Reduction Reaction

“…Another two endothermic process at 509 °C and 684 °C might due to the slight compositional change of Zn‐ZIF‐L . Although the weight of Zn‐ZIF‐L might change a bit, the molten metal chlorides are quite stable below 700 °C . Therefore, the total weight seems constant below 700 °C considering that the content of Zn‐ZIF‐L is only about 2 wt % in the mixture.…”

“…After the temperature is increased to more than 700 °C, the mixture starts to lose weight accompanying with a clear endothermic peak at 859 °C, which might be due to the strong interaction between Zn‐ZIF‐L and LiCl/KCl accompanied with exfoliation, carbonization, and volatile of decomposed chemicals. In addition, vaporization of LiCl/KCl molten salts also happens when the temperature reaches to 800 °C and contribute to the fast weight loss. In contrast, pyrolysis of individual Zn‐ZIF‐L shows a totally different TG/DSC curve that shows much simpler process (Figure S3b).…”

Rare Earth Electrochemical Property Measurements and Phase Diagram Development in a Complex Molten Salt Mixture for Molten Salt Recycle

“…The phase transitions of Li3GdCl6 is also captured. The LiCl-KCl phase diagram was taken directly from our previous work [97]. Then using the Kohler-Toop asymmetric formulism, the ternary phase diagram of LiCl-KCl-GdCl3 was assessed as [22].…”

“…The experimental data used includes the phase information and enthalpy of mixing from literature. Assessment of LiCl-KCl was directly from our previous work [97]. The ternary system of LiCl-KCl-GdCl3 was extrapolated based on the binary systems by applying Kohler-Toop asymmetric formulism [98].…”

“…The LiCl-KCl system has been widely studied and assessed in our previous work [97]. For the KCl-GdCl3 system, Korshunov et al [99] studied it by experiments and reported three intermediate compounds, KGd3Cl10, K2GdCl5, and K3GdCl6.…”