Question

Which method would you suggest for the separation of the metal in the following mixture?

Rare earths

Give reasons for your choice.

Answer 1

For the separation of rare earth metals, the suitable method is Ion-exchange method.

Reason:

1. Rare earth elements (lanthanides) have very similar chemical properties (same +3 oxidation state, nearly identical ionic radii).
2. Because of this, they cannot be separated easily by ordinary chemical methods.
3. In the ion-exchange process, rare earth ions are absorbed on a resin and then eluted selectively with suitable complexing agents.
4. This allows their stepwise separation in pure form.

Hence, ion-exchange method is used for the separation of rare earths.