Abstract: Systems and methods for selectively recovering a target metal from an ion exchange resin are generally described. In certain embodiments, such methods and systems can be employed for metal purification and enrichment of target metal species from mixtures containing contaminating or non-target metals. In some embodiments, ion exchange is accomplished in the presence of one or more species that facilitate the recovery of a metal from a composition further comprising one or more other metals. The recovered metal-containing composition may contain the recovered metal at relatively high purity and/or in relatively large amounts. In some embodiments, the conditions present during ion exchange are varied in a manner that facilitates the enrichment of a metal from an initial (e.g.