Abstract
An ion-sieve manganese oxide was prepared by extracting magnesium ions from Mg2MnO4 using (NH4)2S2O8 as an extracting agent. The preparation conditions of the ion-sieve adsorbent were studied. Mg2MnO4 could be obtained by heating a mixture of MnOOH and Mg(OH)2 in a molar ratio of 1:2 at 900°C for 2.5h. The extractability of Mg2+ reached above 96% by the treatment of Mg2MnO4 with 1-M (NH4)2S2O8 solution at 90°C for 2h, while the dissolution of Mn was less than 0.2%. The adsorbent obtained showed the lithium adsorptivity from sea water; the equilibrium adsorptivity of lithium reached 6.4mg/g.
