Efficient extraction chromatography method for the separation of heavy rare earth elements from various sources

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Heavy rare earth elements (HREEs) are critical for advanced technologies but face supply concerns due to inefficient separation.
• Current solvent extraction methods for HREEs are environmentally damaging and technically suboptimal.
• The demand for HREEs in applications like lasers and high-tech alloys necessitates sustainable and efficient separation solutions.

Purpose of the Study:

• To develop and validate a continuous extraction chromatography method for HREE separation.
• To provide a greener and more efficient alternative to conventional solvent extraction processes.
• To enable targeted separation of valuable HREEs like Terbium, Dysprosium, Holmium, and Yttrium.

Main Methods:

• Utilized ligand-coated C18-silica as a stationary phase.
• Employed mineral acid as the eluent, eliminating the need for organic solvents.
• Verified the method using bench-scale pilots with HREE concentrate and recycled magnet leachate.

Main Results:

• Achieved high purity (≥ 99.9%) for individual HREEs.
• Demonstrated high stability and consistent separation efficiency.
• Successfully separated targeted HREEs, simplifying the overall process.

Conclusions:

• The developed extraction chromatography method is a viable, efficient, and environmentally friendly alternative for HREE separation.
• This green technology has the potential to significantly improve the sustainability of HREE production.
• The method's adaptability allows for targeted separation of high-value HREEs, optimizing resource utilization.