Abstract: Lithium ion-sieve，MnO2·0.4H2O was obtained from spinel type precursor，Li1.33Mn1.67O4，treated with nitric acid. Li1.33Mn1.67O4 was synthesized from LiMn2O4 which was prepared with LiOH·H2O and Mn3O4 by solid state method with different amount-of-substance ratios of Li to Mn.Lithium extraction rate and manganese dissolving loss rate were determined，and saturated adsorption capacity，stability，and pH titration curve of lithium ion-sieve were also studied.The results suggested that the lithium extraction rate and the manganese dissolving loss rate were 62.7% and 6.0%，respectively，after the precursor was washed secondarily by nitric acid.In a 0.1 mol/L NaOH and 10 mmol/L LiCl mixed solution，the saturated adsorption capacity of MnO2·0.4H2O for Li+ was 24.6 mg/g，and lithium ion sieve had a good stability. pH titration curves suggested that lithium ion sieve MnO2·0.4H2O presented excellent selectivity for Li+.

Key words: lithium ion-sieve；solid state reaction；adsorption；Li1.33Mn1.67O4；MnO2·, 0.4H2O