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BeF', concentration would decrease. The changes
in salt composition calculated from the amount of
lithium consumed were too small to be detected
by chemical analysis; however, in some instances
x-ray diffraction anal.yses of salt samples that
had ken cooled to room temperature revealed the
presence of LiF, a phase that would be expected
if the LiF/BeF, mole ratio in the salt were
higher than its original value of about 2. Ob-
viously, more work, conducted under very care-
fully controlled conditions, will be required to
confirm or refute the tentative hypothesis that
water is the cause of the apparent loss of lithium
in reductive extraction experiments.
Despite significant changes in the lithium con-
centration in the metal phase during an experiment,
it was possible to determine the distribution of
europium between the two phases at various tem-
peratures. This distribution is expressed as a
ratio, D, defined4 as
mole fraction of Eu in metal phase
D=- ...................
mole fraction of EuF, in salt phase
The values of D obtained in this study are given
in Table 24.1 and are compared in Fig. 24.1 with
those obtained by Shaffer, Moulton, et ~ 31.~ at
6OOOC. Agreement between the two sets of data
is reasonably good. It also appears that ternperatiire
has no marked effect on the equilibrium distribution
of europium between the two phases,
An emission-spectrographic or a neutron-activation
method was used to analyze for europium in
both the salt and metal phases. The data reported
are from experiments in which the europium balance
was 90 to 110%. Each sample of the metal phase
250
TEMPERA WKE
f 500
0 583 -
GO2 ~
* 605 -
Q 608
A 700
, , 1 1 1
+ill1 /I
T-
0.5 1 2 5
ORNL-DWG 67-44848
LITHIUM CONCENTRATION IN METAL
PHASE (at "70)
Fig. 24.1. Distribution of Europium Between LiF-
BeF2 (66-34 mole %j and Li-Bi Solutions.
this study; solid line, datu of Shoffer, Moulton, et af.
(see Reactor Chem. Div. Ann. Progr. Rept. Dec. 31,
1966, ORNL-4076).
Data points,
was analyzed for lithium by both an emission
spectrographic and a flame photometric method.
In some instances, the values obtained were
markedly different; this is readily apparent in the
data obtained from experiment JF:1,64 ('Table 24.1).
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