Recovery of rare earth elements from electronic waste by diffusion dialysis

Recycling rare earth elements (REEs) contained in electronic waste is of utmost importance due to their ever-increasing use the high-tech sector. In this context, non-polluting techniques represents a real challenge for scientists. work, we demonstrated that clean and energy-efficient process, diffusion dialysis, has great potential recovery neodymium (Nd) praseodymium (Pr), Nd-Fe-B magnets end-of-life computer hard disk drives (HDDs). Four kinds polymer membranes were prepared by blending cellulose triacetate (CTA) polyethylenimine (PEI) with addition di-(2-ethylhexyl) phosphoric acid (D2EHPA), tridodecylamine (TDDA), trioctylamine (TOA) or trioctylphosphine oxide (TOPO). The first characterized several such as water uptake, contact angle, ATR-FTIR, SEM, XRD zeta potential. They further implemented dialysis experiments which diluted HDDs leachates used feed solutions. relevance process REEs was it possible extract up 15% boron spontaneous through CTA/PEI/TOA membrane 6 h lab-scale cell operating batch mode. All positively charged under conditions then, (present mainly form trivalent cations Nd3+ Pr3+) strongly rejected. A fairly good correlation found between uptake transfer, boric molecules passing more easily hydrated membranes. selectivity factor resulted from interplay structure, its ability surface charge. It also be dependent on leachate composition. CTA/PEI/TDDA exhibit greatest B/REE factors, values reaching 3706 140 Nd Pr, respectively. lower towards Pr explained weaker Gibbs energy hydration Pr3+ compared Nd3+.