A Prussian-blue analogue (PBA) ion-chromatography-based technique for selective separation of Rb (as RbCl) from brines.

A new general method is presented for separating pure RbCl from solutions rich in Na and K. The method relies on Rb adsorption via ion exchange performed by self-synthesized PES coated Zn-Hexa-Cyanoferrate material. The procedure starts by passing the wastewater through an ion exchange column, which is thereafter regenerated with 1 M NHCl.