Preparation of Layered Lithium Ion-Sieve by Solid-phase Method and Their Lithium Extraction Performance

Manganese oxide MnO2·H2O (H2MnO3) is regarded as a highly efficient adsorbent for lithium extraction from saltwater due to its superior theoretical adsorption capacity. The precursor Li2MnO3 for H2MnO3 is synthesized using a solid-phase method. X-ray diffraction results show that pure Li2MnO3 was obtained above the temperature of 600°C. The resulting product after lithium removal through acid stripping is lamellar H2MnO3, with a delithiation rate of 76.5% and a manganese dissolution loss rate of 2.98%. The structure of the ion sieve was retained after acid washing. Furthermore, an adsorption amount of 12.3 mg/g is reached in a solution of 250 mg/L LiCl, and showing noteworthy selectivity for lithium in mixed ions solutions.