AbstractA technique is described for the continuous extraction of samarium or ytterbium from rare earth concentrates. Extraction is carried out in a packed column by passing a solution of a lanthanon concentrate countercurrent to a dilute sodium amalgam. A samarium or ytterbium amalgam is formed which flows to a second column, where the rare earth is stripped from the amalgam with hydrochloric acid.Factors controlling the efficiency of the process are discussed.