Effective mine waste management isn’t simply about containment. It’s a complex relationship between science, technology and economic considerations which aims to minimise environmental impact, mitigate risks to human health and foster sustainable practices that endure beyond the life cycle of a mine.

Whilst mining has been conducted for millennia, the storage and handling of associated waste has only in recent decades been the focus of government and public scrutiny according to Associate Professor Anita Parbhakar-Fox from the Sustainable Minerals Institute at the University of Queensland.

University of Queensland’s Sustainable Minerals Institute Associate Professor Anita Parbhakar-Fox.
University of Queensland’s Sustainable Minerals Institute Associate Professor Anita Parbhakar-Fox.

Prof Parbhakar-Fox says if waste materials are not appropriately managed, then a wide range of related environmental issues can easily arise.

“For example, if mine waste contains sulphide minerals like pyrite (FeS2) then under surficial conditions, this can oxidise and generate acid that can elute into the environment impacting ecosystems,” she said.
‘Further, if the geotechnical properties of a mine waste storage facility are inadequate or not properly monitored, then failures can occur resulting in uncontrolled release of mine waste into the environment as we saw in 2019 at Brumadinho, Brazil, where at least 250 people lost their lives.”

To avoid events like this from happening again guidelines like the GISTM (Global Industry Standard on Tailings Management – Global Tailings Review), ICMMs good practice tailings guideline (ICMM – Tailings Management: Good Practice Guide) and even the GARD Guide (GARDGuide ) are available to better guide industry with the challenge of managing mine waste.

Prof Parbhakar-Fox says it is more important than ever to get it right as the global community acknowledges the need for more mining to meet energy transition needs.

“The UN Secretary General said just last month (May 2024) that we ‘cannot make the mistakes of our past’ when it comes to new mining projects so it’s more important now to have the best mine waste management practices in place right at the very start of a mine’s life,” she said.

“A key to this is designing with the closure, or the end, in mind.”

Adopting ESG (Environmental, Social and Governance) Standards

In the past decade, Australia has seen in the EY risks in mining survey, that ESG, licence to operate and climate change have featured highly (if not in the top five) and Prof Parbhakar-Fox explains that the mining sector knows it must adopt the highest ESG standards for a number of reasons.

“One including that financiers are also demanding higher standards to be met,” she says.

“This has led to an explosion of new services and companies offering ESG and LCA (life cycle assessment) guidance as well as companies offering to help the mining sector adopt circular economy practices.

“Mine waste management is very much a part of ESG, so to improve credentials in this area, they must also address improving mine waste management standards.”

Geamana village flooded with waste water from mining, Romania, taken in May 2019.
Geamana village flooded with waste water from mining, Romania, taken in May 2019.

Major Challenges

According to Prof Parbhakar-Fox, there are three major challenges associated with mine site waste management, which is generally regulated by each state government with environmental impact assessments and environmental permitting requirements before, during and after a mine is operating.

She explains the first challenge, the most important, is the geotechnical stability of a mine waste feature.

“If not well designed, then failures can occur…before the 2019 Brumadinho incident, there was a similar failure in Samarco, Brazil, in 2015 and at Mt Polley, Canada, in 2014, however other mine waste types stored in piles or heaps can fail too – for example, in Turkey earlier this year (the 13 February 2024 landslide at the Copler Mine in Erzincan Province, Turkey),” she says.

“In contrast, geochemical challenges such as acid and metalliferous drainage (AMD); the UN once identified AMD as the second biggest environmental challenge facing our global community after climate change, and its impacts can be regarded as more chronic with continual impacts to ecosystems – with one of Australia’s most famous examples being in western Tasmania caused by the historic Mt Lyell copper mines.

“The third is the generation of dusts from mine waste piles or dumps. As the climate continues to evolve, mine waste dumps, historic slag dumps, and spent heap leach piles are subject to more extreme weathering conditions, minerals are by no means passive, they react to more extreme temperatures, more rainfall events, all of which means, for communities located in proximity to these types piles, they are at continual risk through either direct inhalation of particulates derived from mine waste or through the settling of dusts into soils.”

Australian Practices

Australia has periodically released guidelines on how to manage mine waste with one particularly notable series of guidelines published by what was the Federal Department of Industry, Science and Resources back in 2006 and updated in 2016: Leading practice handbooks for sustainable mining | Department of Industry Science and Resources.

This 17-book series was aimed at providing mining managers, communities and regulators with information on sustainable mining practices and spanned topics from biodiversity management to mine closure and was translated into Indonesian, Mongolian, Vietnamese, French and Spanish with the intention that they could be used across the Indo-Pacific and Asia.

Prof Parbhakar-Fox says since then, individual state governments have authored their own state-guidelines on specific aspects of mine waste, and more recently South Australia released an equivalent.

“States like Queensland have since 2019 also mandated progressive rehabilitation to help ensure that as an industry, the mining sector is indeed, designing mines with closure in mind and actively contributing towards this goal during operations,” she says.

“I believe Australia is quite well advanced in comparison to other countries (in terms of sustainability and environmental impact when it comes to mine site waste management practices) – certainly in terms of making headway for reprocessing and revaluating mine waste as a potential resource.

“Countries like South Africa and Canada have been inspired to also set about mapping mine waste across their countries in an attempt to also establish a mine waste reprocessing sector.”

Prof Parbhakar-Fox is also MIWATCH leader.
Prof Parbhakar-Fox is also MIWATCH leader.

Stakeholder Roles

Communities are demanding more from the mining industry and they are demanding better when it comes to mine waste management.

The advent of social media has helped to showcase the mistakes made by the sector, sharing of acid mine drainage seepages or mine waste dump failures.

“Communities are demanding better practices, and why shouldn’t they?” Prof Parbhakar-Fox said.

“Especially as we will be developing more greenfield mining projects in Australia, as well as growing our waste as a resource sector.

“Every community member has the right to be worried about chronic and acute geotechnical and geochemical impacts from mine waste.

“And indeed, governments are responding to this, at a Federal level; there was a Senate enquiry into mine rehabilitation where they toured the country, spoke to experts to understand what are the impacts, the challenges, and how we can improve this at a federal level.

“Mining companies are continuing to improve their ESG standards and are also looking at their mine waste as a potential future resource, so I think we are seeing a total reimagination of the challenge of mine waste.

“And in my opinion, in order to deal with the future challenges we have, reprocessing or designing out waste from the outset (by finding other reuse opportunities) is the key.

“However, this can only be achieved by thorough mineralogical characterisation.

“Without that, we will continue to repeat the mistakes of the past with a higher frequency of failures (due to the evolving climate).”