My name is Anita Parbhakar-Fox and I have been working in environmental geoscience for 15 years. I started out as an environmental consultant in London, following my geoscience degree at the Royal School of Mines, Imperial College, UK. In 2006, I moved to Australia to work as a researcher in the AMIRA P843/A geometallurgy projects. This was my introduction to the Australian mining sector. My role in this project was to investigate and develop new environmental applications for geometallurgical data with a focus on acid rock drainage (ARD) prediction. This provided the opportunity to explore and integrate a range of mineralogical and geochemical datasets with outputs from, what were at the time, new technologies in the mining sector (e.g., hyperspectral core scanners, microXRF instruments, field portable tools). It also gave me an opportunity to meet many mining and METS professionals from a range of companies working across commodities and develop a broader understanding of the mining value chain. After completing my PhD I started a postdoctoral position with CRC ORE where I was a part of the Environmental Indicators team. Here, we developed small-scale and cost effective methods for predicting the environmental impacts of future mine wastes with a focus on ARD, dust and metal bio-accessibility. I finished my term in Tasmania working for the ARC Transforming the Mining Value Chain Research Hub. Aside from coordinating and lecturing in the Environmental Geology BSc and Geometallurgy MSc units, I also led a team of early career researchers. Our focus was on embedding tools to minimise environmental footprints of new mining operations and on mine waste valorisation as an economic rehabilitation approach, with many of our field sites in Australia.
Changing the environment of mining: an interview with Anita Parbhakar-Fox
So, what would your job title be?
I’m currently a Senior Research Fellow at the W.H. Bryan Mining and Geology Research Centre which is one of the six centres that make up the Sustainable Minerals Institute (SMI) at the University of Queensland. I feel like I don’t quite fit into a traditional role, I am part geologist, environmentalist, social scientist, mineralogist, science communicator, lecturer (and very amateur metallurgist!), so I like to think of myself as a geoenvironmental scientist, though I tell my children I am a mine waste crusader! My mission is to raise the profile of mine waste in terms of society, companies and governments understanding there is a serious environmental and societal problem posed by inadequate management and develop practical solutions to help improve management. The main challenge I face is that routinely used practices for characterising and predicting the behaviour of future mine wastes are institutional (and reliant on chemical testing methods) so disrupting the status-quo and encouraging the uptake of new technologies, particularly those that better define the mineralogy and texture of sulphides, the culprit for ARD generation, is not an easy process.
I remember once attending an AusIMM luncheon function, a politician was giving a speech and said that after politicians, mining professionals were probably the most hated in society. We, as an industry, have an image problem, and I’m not just talking about how we engage with communities and traditional landowners as recently seen in the news, but part of this stems from the fact that we don’t mine ore, we mine waste. This waste is so visual and has an impact on ecosystems and communities and these days, society can see these negative impacts very easily thanks to social media. Perhaps unfairly, the benefits and the positive contributions of the mining industry to our modern society can be quickly overlooked in favour of focussing on its waste and the associated impacts, and if one company doesn’t adhere to best practice or falls short of the expected standard, the whole industry gets tarnished with the same brush. The 2019 Brumadinho tailings dam failure in Brazil highlighted, so viscerally, the dangerous impacts that mine waste material can pose to communities and ecosystems if not adequately managed. The international response after this disaster was positive in that the global community pulled together, with the backing of investors, and the Global Tailings Standard was developed and published in mid-2020.
But this is only one part of the problem, and this standard is largely applicable to new and operational sites and their associated waste. If we consider that ‘formal’ mining started in the mid-1800s in Australia, then in the last 170 years we have managed to leave, according to a recent article by Werner et al. (2020), approximately 50,000 inactive sites all of which require some degree of rehabilitation. This is part of what we are being judged on by society, so much so that the trust has eroded and ‘licence to operate’ has been cited for three years as the number one risk in mining by Ernest Young. We need to change this, we need to do better and to me, this is actually something achievable with collaboration and re-examining our values, not just our value propositions.
When it comes to waste, the challenge is to embed the concept that ‘waste is a design flaw’ in the mining industry’s thinking from day one. This has become a mantra to me, I like to put it in lectures or conference talks to get people thinking out of the box as this has the potential to be a game-changing solution. If mine waste is thoroughly characterised and alternative uses for gangue can be found, then mining footprints could theoretically be minimised, socio-environmental factors improved and potentially costs around managing mine waste reduced thus improving the economics for the business. The challenge comes with changing established practices around mine waste, for example introducing an engineered cover over a sulphidic waste rock dump can be about as effective as putting a ‘band-aid on a bullet hole’. ARD still has the potential to develop and seep out and we are back to square one in terms of society’s perception of mining as a dirty, money hungry industry with little respect for the natural environment.
What trends and initiatives do you see in the industry from an environmental and sustainability perspective?
The publication of the Global Tailings Standard was a positive step forward and in years to come, the full impact this has on the mining industry will be assessable. However, the concept of waste valorisation is one that has a growing international profile, for example, The Journal of Geochemical Exploration recently dedicated a special issue to this very topic (December 2020 issue) so this is very encouraging to see that from an academic perspective at least, the ‘waste is a design flaw’ concept is being taken up. Further, several of the larger mining companies have set international ‘challenges’ relating to tailings and waste valorisation. For example the BHP Expande challenge (closed September 2020) was designed to facilitate collaboration between academia and the METS sector to transform the way tailings are managed with a view to reducing and recycling industrial waste. Other companies like Vale and Nexa Resources have since posed similar challenges. So incentivising finding new solutions and financially supporting prototype development through winning seed funding with eventual facilitation of commercialisation is one trend in this space. It’s not just companies engaging in this thinking, government bodies, such as the Queensland State Government have supported research into whether the state’s mine waste contains valuable critical metals to supplement the growing demand for these metals, therefore, actively supporting economic rehabilitation and hoping to stimulate growth of this sector in this state. In Europe too, several H2020 projects are focussed in a similar area (SULTAN, NEMO) and represent collaboration between industry, government, academia and the METS sector.
Another, has been to think about changing the design of waste management facilities altogether. For example, water is a key culprit in both geochemical and geotechnical risks associated, for example, with tailings storage facilities. Therefore, if tailings were dry-stacked then potentially, these risks could be reduced, if not eliminated, so there has been a growing interest in the industry in exploring alternative management strategies. The interest in tailings and mine waste in general has certainly grown in the past five years, it would have been unthinkable to submit a manuscript to Nature on tailings and yet just recently the SMI has had one including new thinking in this area. The SMI, through the Centre for Social Responsibility in Mining, has been at the helm of exploring and improving social governance in mining, so though their research consortiums, sponsored by several mining companies, new systems thinking will start to come into play particularly as we head towards the 2030 deadline set by the UNs Sustainable Development Goals.
What are the latest trends in mine waste characterisation to improve mine planning and waste management practices?
Embracing a geometallurgical approach to characterisation I would say is on trend. True, geometallurgy is not a new concept, I see it often described as this new topic or an emerging field, but as a PhD student I joined the AMIRA P843 project in 2006 and even then it was several years old. However, applying geometallurgical thinking in waste characterisation and management is a growing area (and should be referred to as geoenvironmental characterisation) but, it has been slow to catch on. Fundamentally understanding the long-term behaviour of waste hinges on understanding its mineralogical, chemical textural and physical properties – several of the input variables required for a geometallurgical study. I have often reiterated that mineralogy (and texture) is the key to understanding waste, and as a result, new multi-scale applications for its measurement have been developed. For example, on a macro-scale the application of hyperspectral technologies (e.g., using short-wave infrared or thermal infrared core scanning platforms) has been explored (i.e., through the development of the geoenvironmental domaining index, automated acid rock drainage index and HyLogger geoenvironmental index) more seriously by companies who are commissioning projects in this space. On a micro-scale new automated mineralogy methods to calibrate static testing have been developed as documented in a recent paper in Applied Geochemistry by Carolina Mafra and colleagues. Integrating these data sets using machine learning tools and modelling the results across deposits will help enhance knowledge of a mine’s waste from the outset meaning smarter strategic decisions can be made with regard to waste landform and tailings storage facility design.
Thanks Alan for this very big question! The succinct answer is: i) improve waste sampling (particularly in the exploration and pre-feasibility stages); ii) collection of more geometallurgical type data to enable integrated waste modelling and based on this improve landform or storage facility design; iii) smarter decision making in terms of what to do with the waste – it may be considered gangue in terms of ore-grade but what else can it be used for?; iv) reduce the quantity of waste being processed (i.e., ‘grade engineering’ of waste); v) better waste scheduling and placement tracking (i.e., know what went where); and vi) apply automated continuous monitoring of waste storage facilities long after mine closure. All of these are possible because we are in an exciting age of technological development across many mining related disciplines, as supported, and in some cases led, by the METS sector.
Mining companies apply new technologies for exploration and in active mining phases (e.g. IMDEX) but the industry is slow to embed them into their waste characterisation and management practices. For example, why not use sensor technologies to screen sulphur and segregate potentially acid forming material more efficiently. Why not routinely use hyperspectral cameras to map bench faces to examine clay and carbonate contents to help guide waste handling and scheduling for the rock dumps. Why not use drone technology to map closed sites to monitor changes in slope angle (in the case of dumps) or identify AMD seeps which may then require a team to take action before these problems escalate. Typically, when it comes to waste we go back to first principles and use geologists (or consultants) to make visual assessments or to select discrete samples for destructive static chemical testing (a very 1970s approach) but it doesn’t have to be like this anymore. With the introduction and uptake of field-portable and cheaper technologies, supported by machine learning tools making it easier to automate, assess and propagate algorithms throughout deposits, a better understanding of waste characteristics at a range of scales can be gained during the entire life-of-mine. Ultimately, this can drive financial improvements for the mine’s economics which to me, makes better business sense. Fundamentally though, this sort of change requires demonstration, if companies can see value, then adoption will be fast.
You have been working with improving the management of mine waste materials and have participated in a number of public outreach events to raise awareness of the challenges our society is faced with. Can you tell us a little about this, the importance of it and how do you work with this given the Covid-19 situation?
I remember reading an article about a community in South Africa. A mother was forced to choose between her child going thirsty, or having to drink water heavily contaminated by acid mine drainage. No parent should ever have to make that choice. If we don’t continue to socialise the issues around inadequate mine waste practices then I am worried that more stories like this will be written. We have the tools to reduce the environmental impacts associated with mine waste, we just need to socialise them and encourage governments – state and federal and companies – Tier one or juniors, to routinely use them.
I have been incredibly fortunate to have participated in a great diversity of outreach events, which, for a natural introvert like me is a little daunting at times. But, it is such an important topic that I have had to put that aside. Ranging from participating in ‘a pint of science’, giving a statement at a senate enquiry on mine rehabilitation to featuring on the ABC’s Australia Wide, I have had an opportunity to connect with a range of communities, governments, students and scientists to highlight the issues and introduce solutions towards improving mine waste management. One of my favourite events was at MONA – a relatively new art gallery in Tasmania. Through an environment focussed initiative (Heavy Metals) established by the gallery owners, scientists and artists were thrown together and tasked with coming up with new solutions to improve the health of Tasmania’s rivers. The contribution we came up with was to use food waste – or oyster shells – to neutralise acid mine drainage being generated in western Tasmania, with this culminating in running live science experiments at the museum and contributing a chapter in the book ‘Eat the Problem’ which featured authors including Heston Blumenthal and Germaine Greer. This was a real opportunity to raise awareness of acid rock drainage with a very different international crowd.
However, the most important group I have had a lot of opportunity to interact with is young people – tomorrow’s leaders who, it seems, have far greener ethics and principles than those of the generations before. I have been able to grow a team of early career researchers focussed in this space, so it’s great to see my passion is infectious as they in turn will grow their own teams and inspire others – generational change is a must.
I didn’t state it before but another very significant risk to the mining industry is the declining number of students globally enrolled in geosciences, with mining related subjects in-particular seeing this effect and fundamental mining, engineering and metallurgy courses becoming cancelled. Having an opportunity to lecture to emerging professionals and engaging in STEM outreach activities for school-aged children where possible is so important to show young scientists that their multidisciplinary interests can be expressed through a degree in geology. Even taking my own kids to historic mine sites to look at waste (where safe to do so) and hearing them talk about acid rock drainage to their peers, this helps move raise awareness and creep towards change. I was pleased to see the ABC’s War on Waste – it really connected with the younger generation. I did write to the ABC to ask if any new series’ could include mine waste. I don’t think it’s on the cards in the near future, but this type of communication is vital to help drive consumers change (i.e., to demand products with proven green credentials). It’s worked in other sectors.
COVID-19 turned the world of science communication on its head, no more trips overseas, but instead, a plethora of webinar series being established by a number of governments agencies, societies and academic bodies. This has given us all a platform to connect and engage with a much wider audience. For example, a couple of months ago, I co-ordinated a ‘tailings masterclass’ at the Sustainable Minerals Institute. It was attended by delegates from Canada, UK, Australia, Chile and even South Africa! If this had been an in-person event, we would not have connected with such a diverse audience. It will be good to return to the pre COVID-19 norm, but perhaps now delivering conferences as a hybrid event (with more powerful software platforms available to facilitate this) means the facilitation of wider engagement which is vital for those with limited travel funds, or with family commitments whereby in-person attendance is not always possible.
We see adoption of new technologies, especially in the mining industry taking many years to develop. How can the process of adoption of these innovations be catalysed?
Collaboration, connection and communication. We talk about mining value chains but where is the equivalent chain when it comes to innovation? I have seen, more recently, changes to how for example, PhD programs are being designed. Embedding students for a set period of time with industry sponsors to ensure collaboration and communication of the research, connecting with teams that can take the outcomes to the next step up in the technology readiness or commercial readiness levels (TRL/CRL).
We talk a lot about breaking silo’s, I’ve heard this phrase for the entire duration of my time in Australia. But, it’s much easier to say than do so – I’m not sure that I am yet convinced. Instead, we need to encourage and facilitate collaboration, communication and connectivity between silos and indeed different stakeholders involved in mining. Organisations like METS Ignited have been fantastic at just this, providing opportunities for engagement between the mining industry, METS Sector, government and academia to stimulate new thinking and help find pathways to catalyse innovative ideas. For example, the closed Brukunga pyrite mine in South Australia, under the management of the state government, is being used by the METS sector to test a range of new technologies. Creating spaces like this, giving pilot-scale trials an opportunity to run is essential to demonstrate their applications and see them potentially taken up by the mining industry, so in addition, we need more natural labs and spaces to demonstrate technologies to help move up the TRL and CRL ladders.
Where do you see the value of high resolution, 3D, big data technologies? (i.e. satellite imaging, LIDAR, sensor-based core logging, geophysical technologies and online sensors)
Knowledge is power, the power to make better decisions and all the technologies referenced help enhance our knowledge of a mineral deposit – not just of the ore, but total deposit knowledge. In the context of waste, big data technologies have not yet played a big role, though hyperspectral mineralogy datasets generated by core scanning instruments are starting to make a contribution. To manage this, we now have a growing need to develop a robust knowledge of data science tools (e.g., Python, Matlab, Orange, R, Knime) so it is vital for new professionals working in this space to get a basic understanding, and for those of us who are a little older (or time poor to skill-up), to establish collaborations with those with such expertise to be able to deal with this influx of data and tease the most value out.
Certainly, satellite imaging and LIDAR have been demonstrated to help map and characterise historic and abandoned mine sites and identify appropriate rehabilitation techniques. Sensor based core logging and geophysical tools are becoming more commonplace in a mine waste context, both at early life of mine and later life of mine stages. For example, to understand the subsurface anatomy of a tailings deposit, geophysical technologies can map the hydrogeology, locate sulphides and map out facies horizons. Whilst core scanning technologies can be used, to determine the inherent neutralising potential of an ore deposit and also, identify gangue that can be used opportunistically in the waste landform design (i.e., identifying clay-rich waste ideal for capping). The use of online sensing and sorting for recognising ecotoxic metals, sulphur and neutralising minerals will improve waste segregation and help ensure piles are built to plan more effectively and autonomously. So, all these technologies have an opportunity to revolutionise waste definition, segregation and handling practices for the better.
What are the barriers to adoption of these technologies?
I think I’ve made the point already but when it comes to mine waste and acid rock drainage, the status quo has been long since accepted and unless we see generational change, it will continue to preside. Prior to the 1970s, mine waste characterisation was qualitative, you saw a sulphide, you had a problem. You saw carbonates, you had a solution. In the 1970s, this changed with the introduction of dedicated chemical tests to quantitatively measure acid forming properties, with new chemical tests and frameworks by which to organise these introduced in the 1990s and early 2000s. Let me ask, when was the last significant AMIRA project focussed on ARD characterisation technologies? It was probably the P387/A projects run out of South Australia, which were revolutionary at the time, establishing the AMIRA Handbook for ARD testing which is widely used across Australia and Asia-Pacific, but since then, what has happened? As an industry, we’ve stopped, individual researchers and teams have continued but as a global effort we have yet to unify and propose one global approach. But in the background, technology has exploded. So, the barriers, in many ways, are mental- waste isn’t today’s problem, it’s tomorrows so don’t waste too much money on it now as it’s a cost, it’s a no value material. Coincidentally, I posed this very question to a chief technologist of a mining company recently. I didn’t get a clear answer because it is actually hard to identify real technological barriers as to why we are not improving and significantly innovating in the field of waste management. Even seemingly simple things steps can be taken to improve, for example geologists collecting high resolution core images, uploading them to cloud and then apps performing real-time acid rock drainage assessments and feeding these data into the sites database where it builds deposit knowledge.
What impact does automated mineralogy have in assessing ARD potential?
Automated mineralogy has provided a new insight into mineralogy and texture across various scales. For example, I’ve already discussed the importance of hyperspectral mineralogy instruments, but at a micro-scale, platforms such as the MLA have enabled, for example, a better understanding of the relationships between gangue minerals, particularly reactive sulphides and their neighbours. By understanding microscale processes, we can start to calibrate our static and kinetic data outputs and build better models of ARD evolution, and potentially ecotoxic metal cycling over time.
You have worked with Orexplore technology for a number of years, where do you see the biggest potential for this data in the ARD field?
Gangue materials remain in waste rock dumps and undergo weathering. These are not 2D surfaces, these are large, 3D waste rock particles. Currently, using established techniques like MLA, we are only getting one slice of the sulphide picture when we examine automated mineralogy data. Orexplore allows us to understand sulphide deportment and mineral association throughout drill core and waste materials in a truly unique manner. By being able to quantify and assess sulphides by the acid rock drainage index in 3D we have an emerging opportunity to truly model waste dump evolution in much higher resolution (is that potentially acid forming or PAF material, really PAF?). For me, this is the most exciting opportunity. The next steps would be to build supporting machine learning algorithms to process these data efficiently and unbiasedly, so dedicated R and D in this space but with early establishment of communication, collaboration and connection with academia and the mining industry is vital to drive this and ensure up-take with transformation waste management outcomes.
What do you see as the economic benefits in identifying ARD potential in the pre-feasibility phase as opposed to waiting until the end of mine rehabilitation studies?
I always say to my students, ‘perfect planning prevents pathetic performance’ and in the case of ARD management, this could not be truer. There is a long-term cost in managing ARD long after a project has concluded it is estimated that billions of dollars globally are spent on mine rehabilitation and ARD management, and ARD management is not a short or medium term problem, for example, ARD generation from the > 50Mt Mt Lyell Cu mine historic waste piles in western Tasmania has been modelled and ARD will continue to elute for at least 600 years. This is a real cost, complicated by the fact that we are dealing with physico-chemical and climate factors, influencing mineral transformations and ecotoxic chemical elution. We don’t know what society will look like in 600 years’ time so how can we understand or forecast the cost of managing ARD in perpetuity? Breaking the pollutant linkage chain at the source though detailed waste characterisation and developing effective ARD management strategies is key to strategic management, and using new technologies, gives us the ability to do this.
But in terms of reputation too, and looping back to risks in mining, given the increased media and shareholder interest in the mining industry’s approach to socio-environmental management, not managing waste adequately will do more harm than good to a company as they seek their next asset.
Qualified, dedicated environmental geoscientists need to be embedded in all companies (not just the majors) and allocated a robust budget to enable the definition of the future waste’s geoenvironmental properties – not just a lean budget which is only enough for pulverising hundreds of samples for static testing and running a handful of kinetic cells. The ARD prediction status quo does not provide a high resolution insight into the waste or indeed, provide enough data to understand the evolution of the waste when finally dumped or deposited (remembering that these are still, essentially, geological materials which are going to be subjected to a range of surficial processes). Getting this right early in a project and engaging in gangue optimisation, or transformation, is key. For example, mica’s are used in makeup and in 2018, the global mineral cosmetics market size was US $2.9 billion. This is predicted to double by 2025 with this growth linked to social media giving a platform to bloggers and social influencers seeking ‘natural’ alternatives to unpronounceable chemicals being used on their skin. So instead of dumping micaceous waste, perhaps it’s worth investing in separation technologies (using energy generated by renewables to maintain a green eco-tick) to recover these from waste giving them street appeal to millennials and iGen consumers. There is a use for all mined material, the industry needs to be less myopic, and engage with METS companies more effectively, to support identifying opportunities for addition by product command unlocking this value.
Waiting until the end of mine rehabilitation studies isn’t ideal, but as stated, with new tools and a new thirst for examining if wealth, particularly critical metals, can be sought from existing waste there is a second coming for waste. By products such as Co, Li and REEs, once overlooked, are having their moment and one obvious place to look is in our existing waste. Across the whole life of a mine, there are new technologies and new socio-environmental factors driving opportunities to make significant improvements when it comes to waste management, multi-stakeholder, multi-scale and multi-disciplinary, so in my opinion, this is by far one of the most exciting fields of geoscience to work in.
Who would you want us to interview next and why?
Dr Heidi Pass, she has had a diverse career starting in Canada and then moved to Australia. She has worked in exploration, for IMDEX and was most recently the Chief Geochemist at Goldfields. On the side of this, she embarked on a journey of leadership exploring women’s role in STEM and is a passionate advocate in establishing gender equity.
What question would you like to ask her?
You are also involved in Women in STEM outreach. What advice would you give to a 16-year-old female considering a career in the mining sector, based on your experiences and your research in gender equity?
Anita’s three key tenets to change the environment of mining
01. We mine waste, not ore. Investing in its proper characterisation from day one will lead to improved environmental outcomes at later stages of mining
02. Waste is a design flaw – smarter mining means seeing opportunities to grow the business and reduce long-term waste management costs
03. Education is the key to a greener future – integrated and applied programs to facilitate training and growth of new professionals is vital to safeguard the future of mining