Lithium(1+) and magnesium(2+) extraction and lithium(1+) insertion reactions with lithium magnesium manganese oxide (LiMg0.5Mn1.5O4) spinel in the aqueous phase

Abstract

Spinel-type lithium magnesium manganese oxide LiMg[sub 0.5]Mn[sub 1.5]O[sub 4] was prepared by a coprecipitation/thermal crystallization method. Li[sup +] and Mg[sup 2+] in the spinel-type lithium magnesium manganese oxide could be extracted by an acid treatment. The Li[sup +] and Mg[sup 2+] extraction reaction with LiMg[sub 0.5]Mn[sub 1.5]O[sub 4] and the Li[sup +] insertion reaction with the acid-treated oxide were investgated by chemical, x-ray, DTA-TG analyses, FT-IR spectroscopy, pH titration, and K[sub d] measurement. The extraction and the insertion proceed topotactically by ion-exchange-type mechanisms. The acid-treated oxide showed a lithium ion sieve property from microamount to macroamount of metal ion loading. The selectivity sequence for alkali metal ions was Na < K < Rb, Cs << Li over the pH range studied. 23 refs., 7 figs., 3 tabs.