Determination of the Thermal Conductivities of Several Molten Alkali Halides by Means of a Sheathed Hot-Wire Technique

A modification of the transient hot-wire method has been used for the measurement of the thermal conductivities of electrically conducting fluids. Although the method is probably not as accurate as the concentric-cylinder method in similar applications, it avoids radiation problems which hamper studies with many molten salts. We report here hot-wire measurements of the thermal conductivity values for molten alkali halides. These results indicate that, as was noted by White and Davis(1) for alkali nitrates, the temperature dependence of the thermal conductivities for those substances is positive. Such a temperature dependence seems to be an intrinsic property of ionic liquids and is not associated with the internal degrees of freedom of the ions constituting a molten salt.