Ganesh Pilla, Tobias Hertel, Bart Blanpain, and Yiannis Pontikes of the Materials Engineering Department, KU Leuven, have a new publication entitled A sustainable approach for concurrent recovery of metals from H2 reduced bauxite residue (“red mud”): Process optimization. The article is published in the journal Resources, Conservation and Recycling, Volume 215, April 2025.
Bauxite residue (BR), a polymetallic waste, offers significant potential for valuable metal recovery. This study introduces a low temperature H2 reduction-alkaline (NaOH) roasting, followed by water leaching – wet magnetic separation, aimed at efficient recovery of Fe, Na, and Al, alongside non-magnetic tailings (Ca, Ti, and Si). To minimize H2 consumption, 5 vol % H2 + 95 vol % N2 with 200 L/kg was sufficient. Utilizing response surface methodology (RSM), the optimal H2 reduction process conditions were determined as a temperature of 600 °C and a time of 120 min with 20 wt% NaOH. Under these conditions, the maximum recoveries achieved were 74.4 % Fe (grade = 63.6 %), 84.6 % Al, and 91.6 % Na, with RSM model predicted Fe, Al, and Na recovery values at optimum conditions closely matching experimental results (<5 % deviation). The proposed sustainable process minimizes waste and offers a possible solution for BR processing.
Reference
Ganesh Pilla, Tobias Hertel, Bart Blanpain, Yiannis Pontikes, A sustainable approach for concurrent recovery of metals from H2 reduced bauxite residue (“red mud”): Process optimization, Resources, Conservation and Recycling, Volume 215, 2025, 108051, ISSN 0921-3449, https://doi.org/10.1016/j.resconrec.2024.108051.
Acknowledgement
The authors appreciate the financial assistance provided by the European Union's HORIZON 2020 (HARARE) program with the grant agreement no. 958307. This publication solely represents the authors’ perspectives and does not implicate the Community in any liabilities. The HARARE project details can be found at https://h2020harare.eu/. The authors are profoundly grateful to Richard Durrant for his expert analysis of the manuscript and for offering insightful feedback
