Abstract
This chapter examines adsorption-based separation and recovery of rare earth elements (REEs) from aqueous solutions, covering a range of sorbents including ion exchangers, inorganic adsorbents, impregnated adsorbents, and ligand-grafted adsorbents. It discusses the diverse functional groups involved in REE adsorption and their roles in various separation techniques. The review assesses different ion-exchange resins and their efficacy in REE separation, and discusses novel inorganic adsorbents. Adsorbents known as extractant-immobilized materials synthesized by physically immobilizing extractant onto a solid support provide advantage over solvent extraction but suffer from stability issue. Surface-functionalized adsorbents with ligands chemically grafted onto solid support provide better stability and have been extensively researched for REE separation with silica- and carbon-based support being the major solid support for surface functionalization. Innovative approaches include using magnetic nanomaterials for easy magnetic separation and ion-imprinted polymers for enhanced selectivity. Desorption typically involves mineral acids, though chromatographic separation with complexing ligands offers improved selectivity. While some studies have applied these adsorbents to real samples, there’s a lack of examples demonstrating industrial-scale applications, and further research is needed to bridge this gap and advance practical REE-recovery solutions.
Original language | English (US) |
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Title of host publication | Rare Earth Elements |
Subtitle of host publication | Sustainable Recovery, Processing, and Purification |
Publisher | wiley |
Pages | 299-376 |
Number of pages | 78 |
ISBN (Electronic) | 9781119515005 |
ISBN (Print) | 9781119515036 |
DOIs | |
State | Published - Jan 1 2024 |
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy
- General Earth and Planetary Sciences