Studies On The Synthesize Of Li-Adsorbent And Its Adsorptive Property

Synthesizing of Li-adsorbent and its adsorptive property was studied. It mainly included: synthesizing the precursor of the Li-adsorbent--namely the lithium manganese oxides with spinel structure, washing the precursor and testing the adsorptive property of the Li-adsorbent.In the study of synthesizing process, the spinel LiMnaO4 was prepared by heating a mixture that lithium carbonate and manganese carbonate were mixed with molar ratio of 1.0, at 800℃ for 4-5 hours in the atmosphere. And its purity was close to the pure spinel LiMn2O4. In addition, the complex precursor that mostly consisted of LiMn2O4 and Li4Mn5O12 was made.In the study of washing process, the effect of some factors such as different kinds of acid, various concentration of HCl and different time of washing on the washing result was investigated according to the ratio of Li+ migration and the ratio of Mn2+ losing. So it was considered appropriately that the precursor was washed using 0.2M-0.5M HC1 for 15 minutes or so. At the same time, chemical analyses, XRD and TEM observation showed that each obtained after being washed preserved the same structure as the corresponding precursor. All of those testified that the precursor possessed the spinel structure and ion sieve characteristic.In the study of adsorptive property process, the uptake of the simple sorbent was 23.013mg·g-1 in a mixed solution (100ml 0.05M LiCl+100ml 0.05M LiOH), and that of the complex sorbent was more at the same condition. On the assumption that the adsorption was the same as ion exchange process, it was proved that the process wasn't full ion exchange process through setting out exchange isotherm at different temperature, and the rising of temperature can give adsorption some help and make the process close to full ion exchange one, which enriched the theory of adsorption about its ion exchange mechanism. At last, the better selectivity to lithium was made sure by determining the Kd and S, which indicated that the Li-adsorbent could extract lithium from solution with a spot of lithium.