REDMUD · European Training Network for Zero-waste Valorisation of Bauxite Residue (Red Mud)

European Training Network for Zero-waste Valorisation of Bauxite Residue (Red Mud)

To tackle its (critical) raw material dependency, Europe needs comprehensive strategies based on sustainable primary mining, substitution and recycling. Freshly produced flows and stocks of landfilled industrial residues, such as bauxite residue (BR, a by-product of alumina production from bauxite ore and also known as “red mud”), can provide major amounts of critical metals and, concurrently, minerals for low-carbon building materials. This is self-evident considering the present BR production level in the EU is > 5 Mtonnes/year whereas the cumulative stockpiled level is staggering > 200 Mtonnes (dry matter). BR is a huge secondary source for critical raw materials which are considered key to the clean technologies of tomorrow (electric cars, wind turbines, solar panels, batteries, etc), and hence highly valuable for the European economy, modern technology and environment. The increasing demand for raw materials, their price volatility (e.g. rare-earth elements, REEs) and the market distortions imposed by some countries, confront Europe with a number of challenges, along the entire raw materials value chain. Overall objectives and Challenges REDMUD trained 15 early stage researchers (ESRs) in the science and technology of BR valorisation. The project investigated innovative, eco-friendly and integrated methods for the metal recovery, while valorising the residuals into building materials. An intersectoral and interdisciplinary collaboration of EU-leading institutes and scientists was established, which covered the full value chain: from BR to recovered metals and new building materials. Research challenges include the development of efficient extraction of iron, aluminium, titanium and rare earths (including scandium) from distinct (NORM classified) BRs and the preparation of new building materials with higher than usual iron content. Consortium REDMUD drew its talents from 9 Beneficiaries, including 6 Research Institutes (KU Leuven (coordinator), UHelsinki, RWTH Aachen, KTH, NTUA, UTartu) and 3 Companies (MEAB, Aluminium of Greece/Mytilinaios, Titan). Concurrently, REDMUD is strengthened with 4 additional Partner Organisations (UPatras, UAveiro, Bay Zoltan, Szikkti Labor) as well as an Advisory Board. REDMUD contained 7 WPs, 4 of which are Research Activities: WP1: Fe and Al removal from BR WP2: Ti and REEs removal from BR WP3: Cementitious binders from BR WP4: LCA, NORM and characterisation of bauxite ores and residues WP5: Training WP6: Exploitation, dissemination and outreach WP7: Management Conclusions The REDMUD project has shown that (near-)zero waste valorisation of BR is technological feasible. Different innovative flowsheets have been developed to use BR as a secondary resource for iron, aluminium, titanium, and the rare-earth elements (including scandium), and to use the solid residue that is left behind after recovery of the metals, in new building materials. The main obstacles for the practical implementation of the flow sheets in industry are the high processing costs compared to the intrinsic value of the metals in BR and the strict regulations for use of NORM in building materials. The REDMUD project provided an excellent training to 15 young researchers so that they will be able to make valuable contributions to the European industry and academia in the future.

Data: CORDIS, © European Union