Feasibility of volumetric expansion of molten chlorides by conventional pushrod dilatometry

Abstract

This study is a short communication on progress made in the adaptation of conventional push-rod dilatometry for the measurement of volumetric expansion of liquid salts up to 1300 K. A new crucible design is offered as a practical solution for measurement of liquid salts by this method. Proof-of-concept measurements of the volumetric expansion of sodium chloride (NaCl) are compared to the available data in literature. Measurement of the coefficient of thermal expansion (CTE) of solid NaCl compared favorably to the available data in literature, confirming both magnitude and trend. The average CTE of NaCl (solid) was overline{alpha }_{{{text{NaCl}};{text{Solid}}}} = 5.63 cdot 10^{ - 5} {raise0.7exhbox{1} !mathord{left/ {vphantom {1 K}}right.kern-nulldelimiterspace} !lower0.7exhbox{K}}. The volumetric expansion of liquid NaCl was measured as beta_{{{text{NaCl}};{text{Liquid}}}} approx 3.96 cdot 10^{ - 5} 1/K and is essentially constant from the melt point to 1300 K. The volumetric expansion produced by this method is in reasonable agreement with the available published data and previous measurements made by the authors by neutron radiographic technique.