Dephosphorization Strategies for Recovery of Rare Earth Elements from Monazite: Advanced Processing Methods and Future Directions

Monazite, a phosphate-rich rare earth mineral, presents both an opportunity and a challenge in critical materials supply chains due to its valuable rare earth element (REE) content and refractory phosphate matrix. Efficient dephosphorization is pivotal for unlocking REEs and enabling downstream processing, yet conventional methods often suffer from low REE selectivity, high reagent consumption, and environmentally burdensome waste streams. This review provides a comprehensive analysis of advanced dephosphorization strategies for monazite, including hydrometallurgical, pyrometallurgical, and biochemical pathways. Particular focus is given to novel process intensification techniques, including selective leaching, thermal cracking, flux-assisted reactions, and emerging green chemistry routes. The valorization of phosphate-containing residues and wastes into green transformations is also evaluated. This work highlights key research gaps and outlines future directions for developing cleaner, more efficient, and economically viable dephosphorization technologies for monazite and similar refractory phosphates.