Surface Tension and Density of Molten Salts Based on Equimolar NaCl–KCl with Addition of Fluorides

Abstract

Molten salts based on equimolar (NaCl-KCl) with small addition of fluorides are usually used in remelting secondary aluminum alloy scrap such as Used Beverage Cans. In this work, the surface tension of equimolar NaCl-KCl with addition of NaF, LiF, KF, and Na 3 AlF 6 have been measured by the pin detachment method. Addition of fluorides into NaCl-KCl increases the surface tensions of molten salts. The experimental results are compared to the Guggenheim model as well as the modified Guggenheim model. The binary modified Guggenheim model can give reasonable estimates for ternary salt systems. The density of these molten salts is also found to increase by the addition of fluorides. The implication of the surface tension and density data on ternary salt systems in remelting process is discussed.