Ganesh Pilla, Tobias Hertel and Yiannis Pontikes (KU Leuven) have published a new article in the Journal of Sustainable Metallurgy exploring a multi-step, integrated process for the sustainable valorisation of bauxite residue (BR) — one of the world’s largest industrial solid wastes.
This novel route combines low-temperature H₂ reduction roasting, solution carbonation, and bio-carbon smelting to extract valuable metals from BR. The process yields 96.5% Al recovery with 98.8% alumina grade, while also recovering high-grade Fe (97% recovery, 96% Fe grade) via smelting, using bio-carbon and CaO additives for effective slag-metal separation. Sodium is recovered as Na₂CO₃ in the leachate, further enhancing circularity.
By optimising process parameters (e.g. 80 °C, 120 min, CO₂ flow 25 L/h), the study shows how green chemistry and metallurgical engineering can converge to offer an integrated and scalable approach to BR valorisation.
Reference:
Ganesh Pilla, Tobias Hertel, Yiannis Pontikes. Toward an Integrated and Sustainable Bauxite Residue Valorization, Employing H2 Reduction Roasting, Carbonation, and Bio-carbon Smelting. Journal of Sustainable Metallurgy (2025) 11:1745–1765. https://doi.org/10.1007/s40831-025-01119-x
Acknowledgements:
The authors acknowledge institutional support from KU Leuven’s SIM² Research Group.
