Magnesium isotope separation by ion exchange using hydrous manganese(IV) oxide

The magnesium isotope effects were investigated by chemical ion exchange with a hydrous manganese(IV) oxide. The capacity of manganese(IV) oxide was 0.5 meq g−1. The distribution coefficient of magnesium ions on the MnO2 was determined by a batch method. The heavier isotopes of magnesium were enriched in the solution phase, while the lighter isotopes were enriched in the hydrous MnO2 phase. The separation factor was determined according to the method of Glueckauf from the elution curve and isotopic assays. The separation factors of 24Mg2+–25Mg2+, 24Mg2+–26Mg2+, and 25Mg2+–26Mg2+ isotope pair fractionations were 1.011, 1.021, and 1.011, respectively.