Lithium and its compounds have been widely used in several fields including battery, aerospace and light metal alloys due to their special properties. Recently, gradual exhaustion of lithium resources on land makes it important to extract lithium from seawater and salt lake brine which are rich in lithium.
There are several methods for recovering lithium from lithium resources including precipitation, solvent extraction and adsorption. Among them, adsorption method is suitable for recovering lithium from seawater and salt lake brine due to its simple process and high recovery.
Inorganic adsorbents are widely applied in the adsorption method. Among them, ion sieve materials are most widely used. At present, there are two types of lithium ion sieves―manganese type and titanium type. The ion sieve of manganese type has a disadvantage of big dissolution rate of manganese. Therefore, research on the titanium type with higher chemical stability is becoming more intensive.
Ri Song Ho, a section head at the Institute of Analysis, has prepared a titanium-type lithium ion sieve for recovering lithium from seawater and salt lake brine, and investigated its characteristics.
First, he prepared the precursor of lithium ion sieve (Li2TiO3) by the solid state reaction with lithium carbonate (Li2CO3) and titanium dioxide (TiO2) as raw materials. Then, he prepared a lithium ion sieve (H2TiO3) by extracting lithium from the precursor with HCl solution.
The extraction rate of lithium and the dissolution loss rate of titanium are 91.23% and 0.2%, respectively, during HCl treatment of the precursor. The equilibrium adsorption capacity of lithium on the prepared ion sieve is 38.8mg/g.