METHODS FOR PRODUCTION, RECOVERY, AND PURIFICATION OF GD-153

This review covers methods for production of Gd-153 and its recovery f rom irradiated targets. Two schemes of Gd-153 accumulation, starting f rom a mixture of gadolinium isotopes and a mixture of europium isotope s, are compared. The following methods for recovery and purification o f gadolinium are examined: (1) recovery of Gd-153 from irradiated euro pium, based on reduction of Eu(III) to Eu(II) or to europium metal by alkali metal or zinc amalgams or by electroreduction on various cataly sts; (2) chromatographic purification of gadolinium on cation- and ani on-exchange resins; (3) extraction methods for recovery and purificati on of Gd, using various types of organic extractants; and (4) extracti on chromatography. The influence of various factors on separation and purification of rare-earth elements by these methods is discussed. In addition, such methods are described as metallothermal recovery of Gd, reductive distillation, and electrochemical reduction from melts.