From abstract: "A comparison has been made of methods for producing Fe59 of higher specific activity than that obtainable by irradiating natural iron in the Clinton pile. Five processes have been considered, (1) irradiation of natural iron in the Hanford piles, (2) irradiation of enriched F58 in the Clinton and Hanford piles, (3) Szilard-Chalmers enrichment using ferrocyanides in the Clinton pile, (4) collection of recoils in a phase separable from the bulk of the iron, and (5) the Co59 (n,p) Fe59 reaction in the Clinton and Hanford piles."