Work

Cerium removal from mixed rare earth Sulfate solution by oxidative precipitation with hydrogen peroxide: Batch and continuous studies

Year: 2026

Type: article

Abstract: Cerium removal from mixed rare earth sulfate solutions via oxidative precipitation with hydrogen peroxide was investigated in batch reactors to identify optimum conditions for maximum Ce elimination with minimum rare earth element (REE) losses. Depending on the pH and H2O2 dosage, Ce rejection in a batch setting was below 20% at pH 3, regardless of H2O2 dosage, while at pH 4 and 4.5 and 100% excess of H2O2, it reached 85% and 90%, respectively. The REE losses were between 10% to 50%. Following slurry ageing for 3 h at 80 °C and pH 3, these losses were reduced to between 1% and 7%.Approximately 90% of Ce was removed in continuous reactors operating under the optimal conditions of pH 4 and 100% excess H2O2. An optimized strategy was proposed to further enhance Ce removal while minimizing REE losses. In this approach, after solid-liquid separation, the solution from oxidative precipitation is directed to downstream REE processing, while the solids are aged separately in pH 3 H2SO4. The effects of pulp density, duration and temperature during this separate ageing step were investigated to assess REE sulfate solubility limitations. Optimal conditions were identified as pH 3, 70 °C, ≤ 10% pulp density, and extended ageing (3–4 h). These parameters provided the best balance between maximizing Ce removal while maintaining minimal REE losses in the sulfate system.

Source: Hydrometallurgy

DOI: 10.1016/j.hydromet.2026.106657

Authors: Georgiana Moldoveanu, Vladimiros Papangelakis

Institution: University of Toronto

Language: English

Topic: Extraction and Separation Processes

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Responsible consumption and production, Clean water and sanitation

Open Access status: hybrid

Estimated APC paid: $4,350