Viscosity and Density of Molten Salts Based on Equimolar NaCl–KCl

Aluminum scrap is melted under a cover of salt flux. During melting, the salt becomes progressively viscous and dense as the oxide film stripped from the metal is suspended in the flux. The increase in viscosity and density decreases the coalescence ability of flux and, hence, decreases the metal recovery. The viscosity and density of ternary molten salts relevant to recycling of aluminum scrap were measured in this study. The kinematic viscosity of the ternary salts varied between 0.71×10−6 to 0.96×10−6 m2/s at 1013 K. The density of the molten salts increased by the addition of fluorides.