Corresponding-states correlation for the surface tension of molten salts

Abstract

The dimensionless coordinates, T * = (T b - T)T m /(T b - T m )T and σ * = σT m /σ m T, where σ m is the surface tension at the normal melting temperature, T m , and T b is the normal boiling temperature, have been used to construct a corresponding-states correlation for the prediction of the surface tension of molten salts. Here, the melting temperature is used as a corresponding temperature. It has been shown that the reduced surface tension, σ * , versus the reduced temperature, T * , for molten salts can be expressed as a unique straight-line plot with the linear correlation coefficient of 0.985. The proposed correlation has a simple form for easy calculation, requires only the melting and boiling point parameters, which are usually easy to acquire, and can predict the surface tension for a variety of molten salts at any temperature accurately. In order to lest the prediction accuracy and the range of applicability of the correlation, the surface tension for thirteen salts including alkaline earth halides and chlorides of silver, tin, lead, and bismuth have been calculated and compared with experiment. The overall average absolute deviation is 1.92% and the maximum deviation is 7.20%.