Adsorbent for lithium and a method for the preparation thereof

摘要

The invention provides an adsorbent for lithium in an aqueous medium capable of adsorbing the lithium value even when the concentration of lithium in the aqueous medium is very low as in natural sea water so as to give an adsorbed amount of lithium on the adsorbent comparable to the content in some low-grade lithium ores. The inventive adsorbent is prepared by the steps comprising (a) impregnating a manganese compound with an alkali, e.g. sodium and potassium, or akaline earth, e.g. magnesium and calcium, metal compound by the adsorption of the impregnant in an aqueous solution on to a water-insoluble manganese compound, coprecipitation of manganese and the impregnant element by admixing aqueous solutions of compounds thereof or powder blending of a manganese compound and an impregnant compound, (b) heat-treating the thus impregnated manganese compound at a temperature sufficiently high to form a composite compound between manganese and the impregnant element and (c) leaching the constituent of the impregnant out of the composite manganese compound after the heat treatment using an acid.