Bauxite Residue Valorization and Best Practices: Valorization from Policy, Zero-Emission and Systemic Perspectives
Sponsored by: TMS Light Metals Division, TMS: Aluminum Committee
Program Organizers: Tobias Hertel, Ku Leuven; Christina Meskers, SINTEF; Efthymios Balomenos, Metlen Energy and Metals; Casper Van Der Eijk, SINTEF; Brajendra Mishra, Worcester Polytechnic Institute; Yiannis Pontikes, Ku Leuven R&D
Wednesday 8:30 AM
March 26, 2025
Room: 111
Location: MGM Grand
Session Chair: Tobias Hertel, Ku Leuven
8:30 AM
Developments in EGA’s Bauxite Residue Roadmap: Steven Rosenberg1; Markus Graefe1; 1Emirates Global Aluminium
In 2016, Emirates Global Aluminium (EGA) embarked on an ambitious program to find practical applications for bauxite residue from its forthcoming Al Taweelah alumina refinery and thereby progressively phase out the storage of all bauxite residue from the refinery in the medium to long term. This necessitated the creation of a Bauxite Residue Roadmap, which provided clear guidelines and principles that allowed a comprehensive research program and commercial development to commence well before the refinery had even entered production (2019). This presentation reflects on the successes and challenges in following the Roadmap, the extent to which it had to evolve following refinery start-up, how it has helped clarify which research avenues to pursue and when to abandon programs. Most importantly, it provided a filter to prevent loss of focus and momentum when faced with the many schemes, start-ups and alternate technologies presented to EGA over the years.
8:50 AM Question and Answer Period
8:55 AM
Activated Bauxite Residue Application in Wastewater Treatment: Scott Berggren1; Brajendra Mishra2; Himanshu Tanvar2; 1GRÖN Metallic Group, Inc.; 2Worcester Polytechnic Institute
GRÖN Metallic Group, Inc. has developed a unique mineral oxide based adsorbent product made from recycled bauxite residue – a never ending hazardous/toxic waste from the aluminum industry. The product (called Activated Bauxite Residue or “ABR™”) is a product like Activated Carbon – yet has shown to be more effective (up to 100% in many cases) in removing challenging contaminants such as PFAS, heavy metals and other organic/in-organic compounds from water. Activated Carbon products are produced from materials generating large amounts of CO2 emissions. ABR can be produced with 97.5% lower CO2 emissions, creating carbon credits.The ABR™ can be collected and recycled post water treatment use in a secondary process to permanently destroy the contaminant. ABR™, eliminates waste and reduces contingent liabilities for aluminum companies, addresses global clean water needs, and satisfies five targeted UN Sustainable Development Goals (SDGs).
9:15 AM Question and Answer Period
9:20 AM
BR Valorisation: Can We See It Differently?: Yiannis Pontikes1; 1Ku Leuven
Many publications on bauxite residue select one application and present their findings or defend a more holistic, near-zero-waste process, where variable products emerge. The work herein proposes a different approach: a main “backbone” process that differentiates only in selected unit operations while allowing a range of processing options so that a range of diverse products can be produced responding to market needs. Understandably, this is at odds with the operation of large-scale industries, where capital investment, workforce, and production capacity are all high and are only profitable exactly because of their high efficiency and mere size. Yet, this industrial example is far from agile and resilient and less able to cope with geopolitical uncertainties and market volatility. An example of such a process is presented, where metallic Fe, a new binder, and building elements are produced, from one process that branches out into individual ones, integrating energy production and storage.
9:40 AM Question and Answer Period
9:45 AM
Optimising Bauxite Residue for Use as a Soil Component: Markus Graefe1; Lucky Zaman1; Virender Kumar1; Steven Rosenberg1; 1Emirates Global Aluminium
Soil, in the context of the United Arab Emirates, is an attractive option for bauxite residue usage, because the sandy nature of the native soils lacks water and fertilizer retention capacities, while the climatic conditions of the region impart water scarcity, excessive evaporation rates and solar radiation. The challenge of economically converting bauxite residue, directly from the refinery, into a usable soil substrate material was addressed through in-house and commissioned research at international universities. In August 2023, EGA began producing 80 kg per week of optimized bauxite residue (OBxR) with a pH < 8.0 and an EC < 1.0 mS/cm at Al Taweelah alumina refinery’s first residue-related pilot plant, the Small Soil Manufacturing & Research Facility (SSMRF). We have since produced 30 tonnes of OBxR and installed two demonstration plots. Our presentation provides insights into the process chemistry nature of OBxR, and the performance of EGA’s Turba (Arab. soil).
10:05 AM Question and Answer Period
10:10 AM Break
10:20 AM
Pelletization and Hydrogen Reduction of Bauxite Residue in Pilot Scale: Casper Van Der Eijk1; Arijit Biswas2; Frida Vollan1; 1SINTEF; 2Tata Steel
This work is about the experience gained from the extraction of iron metal from bauxite residue pellets through hydrogen reduction. The pelletizing method was developed in laboratory-scale with the help of a small Eirich mixer (EL1). The production of 2 000 kg calcium-added bauxite-residue pellets with the requisite chemical composition has been performed in a large Eirich Mixture (Type R08W). The pellets were subjected to various tests like tumbler and abrasion tests.The pellets have been reduced in a hydrogen atmosphere in lab-scale, with a focus on fine-tuning reduction characteristics through the variation of parameters such as reduction time, temperature, and gas flows in a thermogravimetric apparatus. After characterisation of the reduced pellets, the optimal parameters for reduction were established. The hydrogen reduction was demonstrated in a rotary furnace with a capacity of about 500 kg.
10:40 AM Question and Answer Period
10:45 AM
Innovative Hydrometallurgical Methods for Extracting Metallic Oxides from Bauxite Residue: Himanshu Tanvar1; Brajendra Mishra1; 1Worcester Polytechnic Institute
The Bayer process, commercialized in the late 1800s, remains the predominant method for alumina production, accounting for over 95% of global output. However, this process generates a significant quantity of solid residue, commonly known as bauxite residue or red mud. For each ton of alumina produced, approximately 1 to 1.5 tons of this residue is generated, leading to a global stockpile estimated at 3 to 4 billion tons stored in containment dams. The current recycling rate of bauxite residue is less than 5%, with major applications in the cement industry. This research aims to scale up a hydrometallurgical process for recovering various metallic oxides from bauxite residue and provide guidelines for industrial application. Large-scale laboratory trials (15-20L scale) were conducted to extract high-purity magnetite, alumina, titanium dioxide, silica and calcium carbonate. Additionally, the potential for recovery of rare earth elements (scandium) within the process flowsheet was also evaluated.
11:05 AM Question and Answer Period
11:10 AM
Hydrogen-Driven Sustainable Multi-Metal Recovery Approaches for Bauxite Residue: A Comparative Analysis: Ganesh Pilla1; Tobias Hertel1; Yiannis Pontikes1; 1Ku Leuven
Bauxite residue (BR), a byproduct of the Bayer process, offers potential for metal extraction. This study evaluated three recovery methods: (a) H2 reduction (600 °C) with water leaching and wet magnetic separation, (b) H2 reduction (900 °C) with water leaching and wet magnetic separation, and (c) H2 reduction (600 °C) followed by smelting with biocarbon. Method (a) achieved 74.4% Fe recovery (63% magnetite), 84.6% Al, and 91.6% Na. Method (b) showed 88.1% Fe recovery (70% pure Fe), 94.5% Al, and 92.6% Na. Method (c) reached 99.3% Fe recovery (96% pig iron), 80% Al, and 95.6% Na. Impurities and poor particle liberation limit Fe grades in (a) and (b), while (c) is energy-intensive. These methods support sustainable BR valorization, recovering Fe, Al, Na, and enriching non-magnetic fractions for further extraction and use in building materials.
11:30 AM Question and Answer Period