The application of poorly crystalline silicotitanate in production of (225)Ac

Actinium-225 ((225)Ac) can be produced from a Thorium-229/Radium-225 ((229)Th/(225)Ra) generator, from high/low energy proton irradiated natural Thorium or Radium-226 target. Titanium based ion exchanger were evaluated for purification of (225)Ac. Poorly crystalline silicotitanate (PCST) ion exchanger had high selectivity for Ba, Ag and Th. (225)Ac was received with trace amounts of (227)Ac, (227)Th and (223)Ra, and the solution was used to evaluate the retention of the isotopes on PCST ion exchanger. Over 90% of the (225)Ac was recovered from PCST, and the radiopurity was >99% (calculated based on (225)Ac, (227)Th, and (223)Ra). The capacity of the PCST inorganic ion exchange for Barium and (232)Th was determined to be 24.19 mg/mL for Barium and 5.05 mg/mL for Thorium. PCST ion exchanger could separate (225)Ac from isotopes of Ra and Th, and the process represents an interesting one step separation that could be used in an (225)Ac generator from (225)Ra and/or (229)Th. Capacity studies indicated PCST could be used to separate (225)Ac produced on small (226)Ra targets (0.3–1 g), but PCST did not have a high enough capacity for production scale Th targets (50–100 g).