The Effect of Menisci on Kinetic Analysis of Evaporation for Molten Alkali Metal Salts (CsNO₃, CsCl, LiCl, and NaCl) in Small Cylindrical Containers

Abstract

Using isothermal thermogravimetric data of alkali metal salts (CsNO3, CsCl, LiCl, and NaCl), we conducted kinetic analysis on atmospheric evaporation to investigate the effect of meniscus on determining the condensation coefficient. In the process of evaporation into an atmospheric gas, molten salt decomposed at the interface between molten salt and an atmospheric gas reacts with chemical compositions of the atmospheric gas to be an equilibrium state. In this atmospheric evaporation, the interface shape of molten salts is affected by the container diameter and the contact angle at the container wall. In the analysis results, the formed concave/convex meniscus led to underestimating the condensation coefficient of molten salts. However, whether the values of the condensation coefficient of molten salts were affected by menisci, the range of the predicted values was still low from 10−3 to 10−5. This result means that the presence of the foreign gas (air and Ar) is a dominant parameter in determining the condensation coefficient of atmospheric evaporation.

Elucidating Ionic Correlations Beyond Simple Charge Alternation in Molten MgCl2–KCl Mixtures

“…Driven by the challenge to find sustainable and safe sources of energy, molten salts have re-emerged as potential coolants in nuclear reactors five decades since the concept was successfully demonstrated. − Because of their minimal vapor pressure − when compared to water, such systems present many advantages including their potential operation near ambient pressure. Chloride-containing molten salts are intriguing and potentially advantageous for certain applications, − including the development of new generation fast-spectrum molten salt reactors, where chloride salts are preferentially used over fluorides because of their higher atomic weight and reduced moderating capacity. , Consequently, mixtures of MgCl 2 with KCl and/or NaCl are considered to be promising media for Pu­(U)­Cl 3 -based fuel salts. , There are engineering models that predict bulk thermodynamic properties of molten salts; , yet, major gaps still exist in our understanding of ionic coordination numbers used as input in these models, intermediate-range order, and molten salt interactions with materials in general.…”

Structure of Molten Alkali Chlorides at Charged Interfaces and the Prediction and Interpretation of Their X-ray Reflectivity

“…Because of the potential operational safety advantages associated with low vapor pressures even at high temperatures, − molten salts are seeing a major resurgence in interest for varied technology applications. In particular, the case for viable nuclear energy production for which salts are used as reactor coolants or mixed with fuel − has started to move beyond the realm of academia and national laboratories and toward the implementation of viable technologies.…”