Isotope enrichment by countercurrent electromigration in molten salts
Doctoral thesis, 1956
A series of isotope enrichments by electromigration in molten salts
lias been carried out during the last, years. The running conditions are
summarized in table 1 and the enrichments achieved are given in
tables 2—13. Practical details such as the arrangement of the electrical
circuits and the construction of the separation columns are discussed.
The number of theoretical plates has been calculated for all samples.
A comparison of all the data shows that the length of a theoretical
unit is about twice as great for columns packed with quartz as for those
with glass, but this length seems to be fairly unaffected by other
parameters, such as grain size of packing or temperature during the
An attempt to reduce the necessary operating temperature by using
salt mixtures in the column is described as well as trials of new cathode
arrangements which, if suc cessful, could have increased the versatility
of t he enrichment method.
There is an obvious systematics in the mass effects for the cations
in halide melts, in fair agreement with the model given by KLEMM.
The cation mass effects are much smaller for nitrates than for halides.
A review of o ther physical properties of these melts does not show any
corresponding division between nitrates and halides. It is possible
that the observed divergence has something to do with the fact
that the nitrate ion is a polyatomic unit lacking spherical symmetry.
The last chapter gives a review of attempts by various methods to
enrich isotopes of Li, Mg, Cl, K, Ca, Cu, Zn, Ga, Br, Rb, Sr, Ag, Cd, In,
Sn, rare earths, Tl, and Pb. On the whole, electromigration in molten
salts has proved to be a widely applicable method, useful for at least
some 15 elements.