Rare-Earth Separations

I was interested to note the reference to the Ames Laboratory at Iowa State University in the article about rare earths (C&EN, Aug. 30, page 9). I worked at the Ames Laboratory from 1950 to 1953 under Frank Spedding, the first director of both the Ames Laboratory and the university’s Institute for Atomic Research.

During World War II, Spedding’s group had quietly provided a substantial amount of the uranium used in the atomic pile at the University of Chicago. He was interested in the chemistry of the rare earths, which at that time were separated by laborious processes. He concluded that small differences in their dissociation constants should make them amenable to separation by ion exchange.

My first work was assisting in the evaluation of that technique, using 1-inch-diameter × 48-inch glass columns filled with Dowex-50 resin. Carefully controlled column preparation and elution conditions allowed the preparation of multigram quantities of high-purity rare earths for the first time by a simple process. Samples of high-purity oxides were supplied to many other research organizations, including other Atomic Energy Commission laboratories. By 1953, the demand had increased substantially, and banks of 6-inch-diameter × 10-foot-long columns were in use.

Jack L. Evans
Sun City West, Ariz.