Isolation of high-purity zirconia from Australian zircon sands using an ion-exchange process

Zirconia produced by acid-leaching zircon sand can be significantly contaminated by other elements leached from the sand. A simple cationexchange procedure has been developed that allows separation of the impurity elements from the zirconium to give zirconia with up to 99.99% purity. The addition of formic acid to the acid-leach solution prior to ion exchange provides the removal of about three-quarters of the hafnium present in the product zirconia.