Liquid-Phase Density Measurements of Various Molten Chlorides

X-ray imaging technique was developed as an accurate way to measure the density of molten chlorides at high temperatures under an argon atmosphere. X-ray transmission allows the capture of an image of the salt sample inside of a furnace. Following a calibration of the pixel size and subsequent image processing, the volume of the liquid salt can be determined and the density calculated. After a method characterization in terms of precision, reliability, and sensitivity on pure salts (LiCl, KCl, and NaCl), different salt mixtures were studied. First, the density variation with the composition of LiCl-KCl, LiCl-NaCl, and KCl-NaCl mixtures at 1123 K was investigated. Then, NaCl-CaCl₂ and NaCl-BaCl₂ systems were examined at 1123 and 1283 K, respectively. A comparison was made between the observed variations in the mixture density and their theoretical ideal behavior.