Selective recovery of rare earth elements from mine wastewater using the magnetic zeolite prepared by rare earth tailings

The effective enrichment and recovery of rare earth elements (REEs) from wastewater holds significant practical value for both the sustainable utilization of REEs and the restoration of ecological environments. In this study, magnetic zeolite was successfully synthesized by using rare earth tailings (RET) as the raw material, with the addition of Fe₃O₄ to introduce a magnetic phase. Th magnetic zeolite exhibits high crystallinity, excellent thermal stability, substantial specific surface area of 483.8 m²/g, and rapid adsorption kinetics. The maximum adsorption capacities for La³⁺ and Ce³⁺ in aqueous solutions were determined to be 123.2 mg/g and 99.9 mg/g, respectively, with adsorption efficiencies remaining above 70 % for La³⁺ and 80 % for Ce³⁺ after six adsorption cycles.Magnetic zeolite was effectively employed to recover REEs from real acid mine wastewater, with La³⁺ and Ce³⁺ recoveries exceeding 90 %, and distribution coefficients (K_d) of 2681.7 mL/g and 5321.8 mL/g, respectively, demonstrating notable adsorption selectivity. Moreover, the magnetic zeolite can be easily separated using an external magnetic field, addressing the recovery challenges typically associated with conventional zeolite. Overall, through this technology, both the loss of REEs from wastewater and the environmental pollution caused by renewable energy technologies are addressed, thus presenting an effective strategy for simultaneous remediation.