Preparation of Spherical PVC-MnO_2 Ion-Sieve and Its Lithium Adsorption Property

Ultrafine powder Li4Mn5O12 prepared by our lab has a high adsorption capacity and selectivity for Li+ in brine(containing Li+,Na+,K+ and Mg2+).However,in the practical application,the ultrafine powder should be formed into the granular adsorbent materials in order to be packed in column with a lower pressure drop of fluid flowing.In this paper,the spherical PVC-Li4Mn5O12 ion-sieve with particle diameter 2.0~3.5 mm was prepared,where using Li4Mn5O12 ultrafine powder as ion-sieve precursor,poly vinyl chloride(PVC) as binder.And it was treated with HCl solution to obtain spherical PVC-MnO2 ion-sieve.The prepared spherical ion-sieve was characterized by Scanning Electron Microscopy(SEM) and X ray Diffraction(XRD).The adsorption/desorption behavior for lithium ion was evaluated by the experimental measurements in the batch and fixed bed adsorbers packed with the spherical PVC-MnO2 ion-sieve.It was found that the prepared spherical ion-sieve well maintained the excellent adsorption behavior of the ultrafine powder with a high Li + adsorption capacity of 5.28 mmol·g-1,and also it has a high Li+ selectivity when recovering Li+ from the solution containing Li+,Na+,K+,Mg2+.With the developed PVC granulation process,the prepared spherical PVC-MnO2 ion-sieve(H type of PVCLi4Mn5O12) makes the ion-sieve adsorption potential application in industry for lithium recovery from brine or seawater.