By Associate Professor Anita Parbhakar-Fox, University of Queensland Sustainable Minerals Institute
Not all that glitters is gold, but unclaimed metals in Australia’s mine waste could find itself adorning the necks of the world’s champions in 2032.
Exhausted, exhilarated and emotional.
The first bars of the national anthem start to play, and your name is called. As you step onto the podium, a great sense of pride washes over you. Not only because you won an Olympic gold medal, but because the beautiful medal placed around your neck was made using recycled metals coming from mine waste – a personal best for an industry that has battled with its environmental credibility.
With Brisbane 2032 fast approaching, the nation is busily preparing to follow the tough acts of Tokyo 2020 and Paris 2024. Although the former Queensland premier had plans for a ‘no frills’ event, there is one area that Australia must perform well in – the medals; not necessarily the final tally (though, as host nation it would be fitting to achieve the top spot) but the materials used to make these career-defining mementos.
Champions of the past
Cast your mind back to Tokyo 2020 – the medals were crafted using metals from e-waste materials which, for a country known for its electronics industry, was a testament to their commitment to circularity. Residents of Japan were said to have donated household items, including mobile phones, with the slogan for the games ‘be better, together – for the planet and people’. In total, eight tonnes of metal was required, and 5,000 medals were produced.[1]
Fast forward to Paris 2024 where the world’s best athletes got to compete in the iconic city with the Eiffel Tower as a backdrop. The lucky ones who placed top three in their event got to own a piece of it too. Every medal from this Olympics contained 18g of iron pieces, mainly cut from Eiffel Tower girders and embedded in the centre.[2]
No major announcements have been made yet as to the medal composition for the Los Angeles 2028 Games.
In the meantime, Australia’s attention must turn towards the 2032 Games and the opportunity they provide to showcase Australia’s mining sectors’ commitment to circularity by using metals recovered from mine waste in the manufacturing of medals.
Recovering metals
Australia reportedly hosts 50,000 sites containing mine waste features [3]. If these contain sulphide minerals – pyrite (FeS2) in particular – they have the potential to generate acid and metalliferous drainage (Figure 1).
Reaching net zero by 2050 would require at least 194 mines or six new mines every year, a recent study by the International Energy Forum[4] shows. Whilst there is pressure to deliver the metals to meet energy transition needs, there is an even bigger challenge to manage the associated mine waste.
For example, one gold medal contains approximately 6g of gold (roughly equivalent to an average wedding ring) and therefore could generate approximately 20t of associated mine waste, which then requires ongoing management to ensure it poses no environmental harm.
Considering the impending mining boom, it is crucial to challenge the current mine waste management status quo. Without innovation, the global community will see more examples of acid and metalliferous drainage and perhaps more devastatingly, tailings dam failures. While these failure events happen in a matter of minutes, the environmental impacts are long-lasting. These impacts do not bode well for obtaining social licences to operate, a matter that consistently features in EY’s annual Top 10 risks and opportunities in mining survey.
Community concerns around new mining projects and the environmental impacts have been topical within Australia in recent years. The mining sector is at a crossroads: continue to build tailings storage dams or find alternative uses for these materials.
The obvious solution is to break the linear chain instead of continuing to be an industry that focuses on take-make-dispose. Integrated and holistic characterisation of mine waste, both existing and future, offers a chance to embed circularity into the mining sector.
Further, in comparison to other industries, the quantity of waste produced in mining is significantly higher – it would take just 26 days to fill the entirety of Sydney Harbour with mine tailings in comparison to the plastics sector, which produces 52Mt of waste per year (equivalent to just three Sydney Harbours). Despite this, more national efforts are placed on embedding circularity (or reducing consumption) in those sectors. The mining sector could be missing an important opportunity.
The ICMM recently reviewed circular economy practices in the mining sector and showcased efforts being made by several of its member companies to reduce ‘value leakage’. Designing out waste was cited in the report as one opportunity to tackle this issue.
Companies like Vale are making headway, with its ‘waste to value’ program, which includes initiatives like the Gelado Project, where iron ore tailings are being reused to make high-grade iron pellets, and the Pico concrete block manufacturing facility where 30,000 metric tonnes of tailings have been turned into 3.8 million pre-mounded concrete products.
Another example is Rio Tinto, where critical metal scandium is being recovered from waste streams generated from its iron and titanium operations in Quebec, Canada.
Mapping mine waste
Closer to home, several State and Territory Governments, as well as Geoscience Australia, have sought to identify critical metals in Australia’s mine waste through a national mapping program, which was largely undertaken by the University of Queensland.
Through the program, 77 sites (Figure 2) containing mine waste features have been sampled using an integrated geochemistry-mineralogy program[5] and the critical metal content was analysed. This data was reported via State Government portals and will also feature in the next iteration of the Atlas of Australian Mine Waste.
Delivery of this pre-competitive data to the industry has seen an upswing in start-up companies, such as Regeneration Enterprises, looking to develop recommercialisation opportunities. Companies like Heritage Minerals and Sibanye Stillwater are already making progress in recovering value from Queensland’s tailings, with the imminent restart of Mt Morgan focused on gold extraction and the second life given to the Century Mine where zinc and silver are being recovered.
But surely, the industry can do more?
mine waste resources identified by the University of Queensland’s MIWATCH Group. Data from NSW is currently under embargo. Image: Rosie Blannin.
Focusing on results from the national mine waste mapping campaign, the location of metals required for all metals needed for Olympic medals (predominantly gold, silver, copper, tin and zinc) can be readily identified.
For example, the distribution of copper can be seen in Figure 3.
Building on this government effort, the opportunity to target Australia’s abandoned mine site waste fertile in these metals and use them as feedstock for the 2032 medals is presented to the industry. The socio-environmental optics on this would be international, indicating to the global community a commitment towards circular economy, and increasing awareness of the fact that mine waste is every consumer’s responsibility, not just the mining company itself.
Looking to the future
Identifying the location of these metals is only the first challenge; the next is to develop sustainable and innovative pathways for their recovery.
New research is underway at the University of Queensland to develop new, and refine existing, technologies, including high voltage pulse [6] and X-ray transmission sorting to better identify and separate the new target ore minerals from waste (Figure 4).
Once separated, efforts are being spent on greener methods to extract the target metal(s) from the ore, with research focusing on exploring and scaling the use of innovative hydrometallurgy methods, biomining techniques and even phytoextraction (Figure 5), with plants such as Trifolium repens. New research is also being established to create value from the new mining waste produced, in an effort to move towards net zero mine waste, a target the global community should edge towards by 2050.
The next step will be to scale these approaches to determine if some quota of recycled mine waste metals can be delivered in time to be incorporated into Brisbane’s 2032 medals. This is only going to be achieved through government-research-industry collaboration.
A challenge must be set to the Olympic Committee to work towards this outcome, where there will be one very clear winner – the environment.
Footnotes:
- Tokyo 2020 The Medals: https://olympics.com/en/olympic-games/tokyo-2020/medal-design
- Paris 2024: how metal from the Eiffel Tower was incorporated into the medals for the upcoming Olympic and Paralympic Games: https://olympics.com/en/news/paris-2024-medals-how-metal-from-eiffel-tower-was-incorporated
- A geospatial database for effective mine rehabilitation in Australia – Monash University: https://research.monash.edu/en/publications/a-geospatial-database-for-effective-mine-rehabilitation-in-austra
- The World Needs 194 New Large Copper Mines to Reach Net Zero: https://carboncredits.com/the-world-needs-6-new-large-copper-mines-a-year-to-reach-net-zero-energy-transition/
- Critical Minerals SA project – Assessing SA’s mine waste for its critical minerals: https://www.youtube.com/watch?v=mF6z5_dvt6Y
- New technology could supercharge efforts to reduce energy consumption in mining: – Sustainable Minerals Institute, University of Queensland: https://smi.uq.edu.au/article/2024/05/new-technology-could-supercharge-efforts-reduce-energy-consumption-mining
