Efficient Recovery of Rare Earth Elements (Pr(III) and Tm(III)) From Mining Residues Using a New Phosphorylated Hydrogel (Algal Biomass/PEI)

With the target of recovering rare earth elements (REEs) from acidic leachates, a new functionalized hydrogel was designed, based on phosphorylation algal/polyethyleneimine beads. The functionalization strongly increased sorption efficiency raw material for Pr(III) and Tm(III). Diverse techniques were used characterizing this correlating performances mechanisms to physicochemical structure sorbent. First, work characterized properties synthetic solutions with usual procedures (study pH effect, uptake kinetics, isotherms, metal desorption sorbent recycling, selectivity multi-element solutions). Optimum found close 5; isotherms fitted by Langmuir equation (maximum capacities 2.14 mmol Pr g−1 1.57 Tm g−1). Fast kinetics modeled pseudo-second order rate equation. highly selective REEs against alkali-earth base metals. remarkably stable operation (using 0.2 M HCl/0.5 CaCl2 successfully applied leachates Egyptian ore (pug leaching) after series pre-treatments (precipitation steps), sorption, elution. precipitation using oxalic acid allows recovery pure REE precipitate.