Zone Refining of High Purity Ce and Gd Metals

Abstract

In work reported at the 13th Rare Earth Conference, zone melting was shown to move impurities in commercial purity rare earth metals. The interstitial impurities O and N moved in the opposite direction from the zone while metallic impurities moved with the zone. We report here the results of further experiments using Ames Laboratory high purity rare earth metals as starting material. Analyses of a zone melted bar of gadolinium showed that the metallic impurities at the starting end of the bar were the lowest ever observed in gadolinium. Over half of the length of the bar had been purified with respect to O and N. The results obtained on cerium metal by this technique are also given.