Extraction of lithium from LiMn2O4 by ammonium peroxodisulfate and lithium isotope selectivities of adsorbents thus obtained

Extraction of lithium ions from LiMn2O4 by ammonium peroxodisulfate ((NH4)(2)S2O8) was studied, and properties of adsorbents thus obtained (MnO2(Li)) were examined with a special focus on their ability to separate the lithium isotopes. Under well-controlled conditions, (NH4)(2)S2O8 was an excellent lithium ion extractant, with satisfactorily high degrees of lithium extraction while maintaining minimal dissolution of manganese. The maximum value of the Li-7/Li-6 isotopic separation factor with MnO2(Li) thus prepared was 1.014 at 25 degrees C, which was several times larger than those of commercially available organic ion-exchangers.