Self-Separation Of The Adsorbent After Recovery Of Rare-Earth Metals: Designing A Novel Non-Wettable Polymer

In solid phase extraction method, the adsorbent separation is very challenging and is one of the limiting factors for using batch process. As a solution to this problem, a self-floating (SF) adsorbent with simultaneous separation from water is developed in this study. The adsorbent has a very high performance for extracting and recovery of the rare-earth element (REEs), especially Yb3+, which has not been reported by other organic adsorbents, so far. The designed adsorbent is very low cost and can be easily prepared by using alkyl ketene dimer (AKD) as a commonly used sizing agent in pulp and paper industry. The designed polymer was used to remove La3+, Ce3+, Pr3+, Nd3+, Dy3+, and Yb3+ from aqueous solutions. The adsorption of the ions showed that REEs with smaller ionic radii have more tendencies towards the AKD-based vinylogous amide-diglycolamic acids self-floating (AVD-SF) polymer with the highest adsorption of 191.87 mg.g(-1) for Yb3+ ions at pH = 5.5. The adsorption isotherm of Yb3+ ions fitted with Freundlich model and the kinetics isotherm fitting confirmed the pseudo-second order model. The SF adsorbent was easily separated from water within 30 min. The reusability test showed that both the performance and structure are reserved after 10 cycles.