A novel, low-cost and robust method for determining molten salt density at high temperatures

摘要

A pycnometric method was utilised to determine the liquid density of carbonate and/or chloride salts at high temperatures. When compared to alternative methods, the measurements were quick and repeatable using common laboratory equipment. The methodology was validated using sodium chloride as a reference material with an error of +/- 0.6% when compared to other literature sources. Overall, the absolute measurement error was found to lead to a +/- 0.3% uncertainty for the measured values where the maximum error was due to the determination of the meniscus volume. This methodology was then used to study the liquid density of several other promising molten salts (32.1:33.4:34.5 wt% Li2Na2K2-CO3, 41.57:25.43:33.0 wt% Na2CO3:NaCl:KCl, 59.45:40.55 wt% Na2CO3:NaCl, 47.19:52.81 wt% Na2K2-CO3) and found to have good agreement when compared to other studies and methodologies (+/- 7.6% from predicted). In all cases it was found that the liquid density decreased linearly from the melting point.