EU-funded project turns bauxite residue into sustainable roads: RemovAL success story

The European Union (EU) can bolster its recycling objectives by utilising waste generated during the production of aluminium, nickel, and other industrial materials. Recognising these challenges, a team of researchers secured funding from the EU to address the issues surrounding red mud. Their project, named RemovAL, spanned five years until April 2023.

Their innovative solution involved repurposing bauxite residue to pave roads, exemplified by the project's implementation at the Aughinish aluminium refinery. In Limerick, Ireland, nestled within the confines of a former aluminium refinery, lies a pioneering initiative set to reshape Europe's approach to waste management.

About RemovAl

RemovAl is a EU-funded cooperation project about removing waste from the primary aluminium and alumina production. RemovAL aims to tackle environmental challenges and technological hurdles in the aluminium industry by integrating and enhancing existing technologies for sustainable processing of:

• Bauxite Residue (BR)
• Spent pot lining (SPL )
• Other by-products

Here, a 500-meter road stands as a testament to innovation, constructed atop a foundation crafted from an unlikely source: bauxite residue commonly referred to as red mud. This concrete thoroughfare at the Aughinish refinery facilitates transportation and symbolises a significant stride towards the EU's ambitious recycling objectives.

'Landfilling is a practice that we want to move away from. Even if there is zero harm to the environment, you are still using up lots of space and throwing away half your material," stated Dr Efthymios Balomenos, who co-led the project.

Balomenos highlighted that Europe must implement incentives like subsidies or regulations for the aluminium industry to adopt more sustainable practices. These measures would promote the utilisation of bauxite residue and other metallurgical by-products as preferable alternatives to newly mined raw materials, thus advancing the sector's environmental objectives.

RemovAL aimed to achieve waste reduction

RemovAL's collaborative effort brought together a diverse array of academic and industrial stakeholders, including Aughinish Alumina, Rio Tinto in France, and the Greek mining and metallurgy company Mytilineos. Conducting field trials across industrial sites in Germany, Greece, and Ireland, the project sought to validate novel approaches for utilising bauxite residue in commercially viable applications. At its core, RemovAL aimed to reduce waste without incurring prohibitive additional expenses, prioritising sustainable solutions aligned with economic feasibility.

Various processing technologies serve as nodes, allowing for flexible pathways based on waste characteristics, availability, and logistical considerations between waste producers and end-users. RemovAL aims to tackle environmental challenges and technological hurdles in the aluminium industry by integrating and enhancing existing technologies for sustainable processing of BR, SPL, and other by-products, generating revenue.

RemovAL for constructing road

The RemovAL initiative successfully demonstrated the viability of utilising bauxite residue as the foundational or subbase layer for constructing roads. Traditionally, roads' subbases are composed of low-grade crushed stone, serving as a sturdy platform upon which higher-quality foundation layers are built. At the Aughinish refinery, standard road-building equipment was employed to lay, compress, and level the bauxite residue, ensuring its seamless integration into the infrastructure.

In an extensive monitoring period exceeding one year following its construction, the road proved its integrity by showcasing no signs of chemical leakage. Furthermore, RemovAL unveiled the potential for extracting valuable materials from bauxite residue, aligning with the EU's strategic imperative to diminish dependence on foreign suppliers for crucial industrial resources.

Typically comprising approximately two-fifths iron oxide, one-fifth aluminium oxide, 6 per cent silica, and 5 per cent titanium, bauxite residue also harbours rare earth elements. These rare earths, a group of 17 metallic elements with unique properties facilitating technological innovation across various sectors, underscore the untapped potential residing within red mud.

Projects in Greece and Norway

At project sites in Greece and Norway, RemovAL employed an innovative process involving smelting bauxite residue within electric arc furnaces. This method yielded an iron alloy suitable for integration into steel manufacturing processes. Additionally, the project successfully extracted scandium, a rare earth element crucial for enhancing aerospace components' strength and corrosion resistance.

Following these extraction processes, the residual bauxite residue transformed into a material conducive to incorporation into cement mixes, further diversifying its potential applications. Despite the technical achievements showcased during the demonstrations, challenges persist, primarily centred on cost considerations. Using bauxite residue alternatives proves less financially lucrative than utilising locally sourced 'virgin' raw materials, posing significant economic hurdles.