Multi-objective optimization of chromatographic rare earth element separation.

Area of Science:

• Chemical Engineering
• Materials Science
• Separation Science

Background:

• Rare earth elements (REEs) are critical for modern technologies, driving demand for efficient separation processes.
• Chromatography is a promising method for REE separation, but requires careful process optimization.
• Existing optimization studies often focus on only two objectives, neglecting crucial factors like product pool concentration.

Purpose of the Study:

• To develop and evaluate a multi-objective optimization strategy for chromatographic separation of REEs.
• To incorporate productivity, yield, and product pool concentration as key optimization objectives.
• To address the scarcity of tri-objective optimization studies in REE separation.

Main Methods:

• Model-based optimization of a batch chromatography system.
• Simultaneous optimization of productivity, yield, and pool concentration for samarium, europium, and gadolinium separation.
• Evaluation of performance metrics including purity and yield for the target component, europium.

Main Results:

• A novel tri-objective optimization strategy was successfully applied to batch chromatography for REE separation.
• Achieved desirable operating points with high europium productivity (0.61–0.75 kgEu/m³·h⁻¹) and pool concentration (0.52–0.79 kgEu/m³).
• Maintained high purity (>99%) and yield (>80%) for europium throughout the optimized separation process.

Conclusions:

• The proposed multi-objective optimization strategy effectively balances competing objectives in REE chromatographic separation.
• This approach provides a generalizable framework for optimizing rare earth element processing.
• The findings support the advancement of chromatography as a viable industrial method for REE separation.