PREPARATION OF HIGH-PURITY GD-153 .1. EXTRACTION-CHROMATOGRAPHIC PURIFICATION FROM ELEMENTAL IMPURITIES

The influence of Li, Na, Ca, Al, and Fe on the Gd distribution in the extraction-chromatographic system D2EHPA-decane-HNO3 is studied. It is demonstrated that Li, Na, Ca, Fe(II), and Al affect the Gd distributi on by a mechanism related to competitive extraction. Besides the compe titive extraction, Al also exerts an effect through a mechanism involv ing the ability of the Al complex with D2EHPA to extract rare earths. Trivalent Fe affects the Gd distribution through a mechanism connected with the extractive ability of Fe(III) salts of D2EHPA. The amount of Gd extracted by FeY3.2HY is proportional to the Fe content in the ini tial solution. The quantities C(d) for Li, Na, Ca, Al, and Fe are dete rmined. The results are used to develop technology for producing Gd-15 3.