ORNL-4191 - the Molten Salt Energy Technologies Web Site

F. J. Smith C. T. Thompson
The transpiration method for obtaining liquid-
vapor equilibrium data is being used (1) to cor-
roborate data obtained by the equilibrium still
technique and (2) to determine relative volatilities
for compounds of interest that have not yet been
studied. The apparatus being used closely re-
seiiibles that described by Cantor.'
'The initial experiments were made with LiF-
BeF, (86-14 mole %) over the temperature range
920 to 1055OC. Plots of the logarithms of the
apparent vapor pressures of LiF and BeF, (based
on the assumption that only LiF and BeF, were
present in the vapor phase) vs 1/T were linear,
although some scatter was evident in the data
points for BeF,. The relative volatility of EeF,
with respect to LiF was 4.0 I 0.2 over the tem-
perature range investigated. This is in i-eason-
able agreement with a value of 3.8 reported by
Cantor' for LiF-BeF, (88-12 mole %) at 1000°C.
242
L. M. Ferris
Recent experiments with L.iF-BeF, (90-10 mole %)
gave a relative volatility of 4.7 (WeF, with re-
spect to LiF), which is in good agreement with
the average value of 4.71 obtained by Hightower
and McNeese' using an equilibrium still. Experi-
ments with LiF-BeF,-CeF, (85.5-9.5-5 mole %)
gave vapor samples in which the concentration of
CeF, was below the limit of detection by spcctio-
chemical methods. The relative volatility (CcF,
with respect to LiF) was less than 1 x lo-,, in
agreement with the reported3 value of 3.33 x 10W4.
'Reac!or Chem. Div. Ann. Progr. Rep!. Dec. 31,
1966, ORNL-4076.
'M. E. Whatley to I). E. Ferguson, private communication,
June 12, 1967.
,M. E. Whatley to D. E. Ferguson, private communication,
July 20, 1967.
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