|About this Abstract
||MS&T22: Materials Science & Technology
||Thermodynamics of Materials in Extreme Environments
||Melting Point, Enthalpy of Fusion, and Excess Heat Capacity of a FLiNaK Determined by the CALPHAD Method
||Juliano Schorne Pinto, Johnathon C. Ard, Mina Aziziha, Kyle Foster, Jacob Yingling, Amir Mofrad, Matthew Christian, Theodore M. Besmann
|On-Site Speaker (Planned)
||Juliano Schorne Pinto
We have of necessity revisited the thermodynamic models and values for the molten salt coolant FLiNaK (46.5 LiF–11.5 NaF–42 KF mol%) as part of the Molten Salt Thermal Properties Database − Thermochemical (MSTDB−TC) development effort, using additional excess Gibbs energy terms to allow the capture of any excess heat capacity (ΔCp) from mixing of the salt components and obtain an accurate enthalpy of fusion (ΔHfus). This required using the CALPHAD method to reevaluate the heat capacity and heat content, and vapor pressures over, solely LiF, NaF, and KF, as well as for their constituent pseudo-binary systems. Finally, internally consistent values were determined using observed phase equilibria, enthalpies of mixing (ΔmixH), ΔHfus, and ΔCp, producing a thermodynamic model for the pseudo-ternary system that predicts a eutectic composition of 46.7 LiF–11.4 NaF–41.9 KF mol% and melt temperature of 735.2 K, and computed Cp, and ΔHfus in good agreement with measured values.