2019-Sustainable Industrial Processing Summit
SIPS2019 Volume 1: Angell Intl. Symp. / Molten Salt, Ionic & Glass-forming Liquids: Processing and Sustainability
| Editors: | F. Kongoli, M. Gaune-Escard, J. Dupont, R. Fehrmann, A. Loidl, D. MacFarlane, R. Richert, M. Watanabe, L. Wondraczek, M. Yoshizawa-Fujita, Y. Yue |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2019 |
| Pages: | 177 pages |
| ISBN: | 978-1-989820-00-1 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Estimation of molten salts density in a wide temperature range
Alexei Potapov1; Alexander Salyulev1;1INSTITUTE OF HIGH TEMPERATURE ELECTROCHEMISTRY, Ekaterinburg, Russian Federation;
Type of Paper: Regular
Id Paper: 98
Topic: 13
Abstract:
It is known that the density of the most molten salts is well described by linear equations: d = a + b*T, where d is the density of molten salt; a, b are constants; T is the temperature, K. Such equations are convenient for small extrapolations. However, at temperatures near the boiling point and higher, the density of melts deviates markedly from the linear relationship to smaller values.
The technique for the long extrapolation of data on the melts density, which considers the non-linear decrease in density of melts at high temperatures (near and beyond boiling point), was proposed. This technique is based on the use of the Rackett's equation [1-3].
The choice of the equation was based on the comparative analysis of the accuracy of various equations for density calculations. It was found that Rackett's equation is the most precise, the uncertainty,ur(d), does not exceeds 0.005, which is almost equal to the error of the density experimental determination. The analysis was carried out using the density data on a large amount of molten chlorides (BiCl3, BeCl2, ZnCl2, PbCl2, InCl3, ZrCl4 et. al.) and other inorganic compounds [2,3]. The coefficients A and B in Rackett's equation [1] were calculated using only the low-temperature data on the melts density and then they were extrapolated to the critical temperatures. The critical temperatures values, Tcr., included in the Rackett's equation are available for many molten salts, for example [2,4].
We also considered various ways to estimate Tcr. in the absence of reference data. It is shown that Rackett's equation, in the mathematical sense, is very stable relative to the choice of the value Tcr. This is a significant advantage, since the critical temperature is difficult to determine experimentally and often has to be evaluated.
Thus, the method to extrapolate the density of molten salts to high temperatures, up to Tcr, with a small uncertainty was proposed.
Keywords: Molten salts; Density estimation; Rackett's equation.
Keywords:
Chloride; Density; Moltensalt;References:
[1] H.G. Rackett, J. Chem. Eng. Data 15 (1970) 514-517.[2] A. G. Morachevskiy, I. B. Sladkov, Physico-chemical properties of molecular inorganic compounds. Experimental details and calculation methods, Saint Petersburg: Chemistry (1996) 312 p. (in Russian).
[3] A. B. Salyulev, A. M. Potapov, J. Chem. Eng. Data 60 (2015) 484-492.
[4] C. L. Yaws, Thermophysical properties of chemicals and hydrocarbons, Norwich: William Andrew (2008), 809 p.