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A D V A N C E D
M A T E R I A L S
&
P R O C E S S E S | J U L Y / A U G U S T
2 0 1 5
9
SEPARATING RARE EARTH
METALS WITH UV LIGHT
Researchers from the KU Leuven
Department of Chemical Engineering,
Belgium, discovered a method to sepa-
rate two rare earth elements—europium
and yttrium—with UV light instead of
traditional solvents. “The UV light in-
fluences the electrically charged parti-
cles known as ions. Both europium and
yttrium have three positive charges per
ion. When we shine UV light upon the
solution of europium and yttrium, we
add energy to the system. As a result,
one positive charge per europium ion is
neutralized. When we add sulphate, only
the europium reacts with it. The result is
a precipitate that can easily be filtered,
while the yttrium remains in the solu-
tion,” says Professor Tom Van Gerven.
The UV light does not leave behind
any harmful chemicals in the liquid and
Illustration of the separation of rare earth metals with UV light. Courtesy of KU Leuven.
the separation efficiency and purity in
synthetic mixtures is very high—more
than 95% of the europium is recovered
from the solution. The precipitate it-
self is 98.5% pure, so it contains hardly
any traces of yttrium. For more infor-
mation: TomVan Gerven, +32.16.322.342,