"There’s a rise in the use of digital technologies for mining processes"
Mining operations affect natural water systems during the entire mine life cycle, from exploration, to operations, to closure. The potential impacts of mining call for water management strategies that consider not only the mine site but the catchment where it operates.
Mining operations face water-related challenges that already exist today and are likely to intensify in the future: on one hand, there are water supply concerns in water-stressed areas; on the other, preventing the release of polluted water into the environment is a major issue. In this interview with Jo Burgess, Managing Director South Africa & Head of Trial Reservoir at Isle Utilities, she answers our questions on management strategies to minimise the impact of mining operations.
Can you tell us briefly about your career path and your current role at Isle Utilities?
My current role at Isle is Managing Director of the South African Business and Head of the Trial Reservoir. My current priority is to grow the Trial Reservoir whilst delivering projects in a range of areas where we see there is a big impact to be made, including that of mining impacted water.
Almost all of the water challenges in the mining industry can be distilled down to one of two things: too much water or not enough
Like many people looking backwards, things make sense: My career path looks like a neat line from leaving the education system to now, but in reality, I didn’t plan it this way. I finished my PhD at Cranfield University and that's where I had my first job, as a postdoc Research Officer.
Then I decided to make the move to South Africa and I got a postdoctoral research fellowship at Rhodes University, in the Eastern Cape province. That began my career in academia: first as a post doc, then as a lecturer and then as Head of Biotechnology. And that's where I started doing my first work on mining-impacted water. The mining industry is a cornerstone of the South African economy and it's almost impossible to work on environmental biotechnology and not be involved with the mining industry.
Now - as well as my day job - I’m an honorary professor at the University of Cape Town’s Centre for Bioprocess Engineering Research, still doing research work on industrial wastewater, including mining-impacted water.
What are some of the most pressing challenges of water management in the mining sector?
Almost all of the water challenges in the mining industry can be distilled down to one of two things: too much water or not enough. This means that the requirements for water related innovations in the mining industry fall into two major camps and their application is very much a local issue. There is either treatment of excess water, or recovery and re-use where there is insufficient water.
That's clearly a bit of oversimplification; there are all sorts of issues around values recovery for example: residual metals and reagents that are added in the metal mining and refining processes. This is in addition to tailings management and water desalination which is not just sodium chloride but any dissolved solids in mining impacted water, primarily sulphur salts. And then of course there’s passive acid mine drainage / acid rock drainage technologies or techniques that are required for mines which have closed already or which are about to close.
A truly passive system that doesn't cost very much to run and requires almost no maintenance is like the Holy Grail of the mine water sector. It doesn’t exist yet.
Water connects a mining operation to the local landscape and communities. To what extent are water supply and discharge issues a priority for mining companies?
If water supply and discharge issues affect the core business of a mining company, then they are a very, very high priority. Typically, however, if they don't affect the core business of extracting a resource and refining it, then expenditure on water supply and discharge issues become a grudge purchase and a very low priority.
The mining industry itself needs to be much more open and willing to communicate bad news as well as good news
Obviously, it's not possible to paint the whole mining industry with the same brush. There are some companies with ambitious corporate environmental stewardship goals that really genuinely work towards good environmental and water stewardship practices. However, there are others that only pay lip service to these kinds of matters, and in those cases they just do enough to keep themselves out of court. And in a small number of cases, they just do enough to keep themselves out of court only if the fine is higher than the cost of taking mitigating action.
I think in general it's possible to say that the outlying exception is the segment of the mining industry involved in the extraction of rare earth elements for energy storage in the renewable energy industry. Those kinds of companies see themselves very differently from the other mining houses. They see themselves as part of the green energy revolution and they act accordingly. They're very serious about their water and environmental protection activities.
Competing water demands and the unpredictability of water supplies due to climate variability can affect the reliability of water sources for mining. Are these risks driving innovation in the mining sector? Could you highlight a recent success story?
The risks of running out of water - actual physical water shortages - and the risk of running out of a continuous supply of the correct quality water to sustain the activity of the business are the greatest risks driving innovation in the mining sector at the moment. Both of these risks are the drivers for on-site and between site water re-use and they are the drivers for water efficiency and for closer control of mining processes. By far the fastest growing area of innovation in the mining sector, as it relates to water anyway, is that of digital technologies and remote monitoring and control of water volumes, of water quality and of reagent utilisation.
Mine closure and mitigating the water risks associated with closure need to be brought in at the beginning, at the exploration stage
I’d like to highlight the eMalahleni Water Reclamation Plant (EWRP). It's a great example of what can be done if companies are willing to collaborate. It actually uses fairly standard technology, or what has become standard technology in large part because the EWRP was the first private sector organisation to implement it in South Africa. The EWRP is a collaboration between Anglo American, Eskom what was BHP Billiton at the time. It's a joint venture that takes mining impacted water which is in excess to the mine's requirements and would require treatment to be discharged the environment. And it treats it to potable standards to be provided to the local municipality. The pathway through the regulatory system to enable the EWRP to become a water service provider was tortuous, to say the least. But the EWRP blazed the trail and showed that mining impacted water can be used for productive, consumptive use and the private sector and the public sector can indeed work together to provide a system that treats water, protects the environment, provides water to people, and using the gypsum by-products from water treatment, built hundreds of houses for those who need them.
Wastewater treatment by the mining sector has sometimes been in the public eye due to incidents with tailings ponds. Do you think there is room for improving the reputation and transparency of the mining sector in terms of its water stewardship?
Oh, absolutely. Yes. There's lots of room for lots of improvement. There are some very good reasons why communities distrust the mining industry. The mining industry itself needs to be much more open and willing to communicate bad news as well as good news, because sooner or later the truth comes out anyway.
A significant portion of the world’s mines are expected to close in the not-so-distant future. Are there specific considerations for water monitoring and management during the mine reclamation stage?
There are specific considerations on mine sites which are closing or have closed - they should be put back to the pre-mining state as far as that's possible to do, although that is really an impossible task. However, where the industry has gone wrong in the past is that mine closure and mitigating the water risks associated with closure need to be brought in at the very beginning, before the ground is even broken, at the exploration stage of starting a mine site. Leaving closure and site reclamation planning until the closure stage is the reason why we have so many legacy issues with mine sites that contaminate the environment in perpetuity.
“Mining” of above ground dumps will provide us with metals while dealing with the environmental legacy of older mining practices
It's estimated, for example, that almost all of the dissolved tin and silver in rivers in the United Kingdom comes from Roman-era mining. Legacy mine sites that have closed continue to leak metals into the wider environment for centuries, if not millennia after closure. Now we know that this happens, we can plan at the mine exploration stage for responsible material storage and mine closure and reclamation, but we can't leave it until the reclamation stage.
What do you see in the future of water in mining?
Typically, if they don't affect the core business, expenditure on water supply and discharge issues become a very low priority
I think the future of mining will include a lot more automation. There’s a rapid rise in the use of digital technologies, both for the mining processes themselves but also for site and environmental monitoring and risk mitigation activities. The other big trend I foresee emerging in the next few years is the emergence of mining companies which don't actually excavate. There are mega dumps and smaller dumps around the world originating from historical mines that were started 80 to 150 years ago, and back then the metallurgical extraction processes were not as efficient as they are today. So a lot of those waste dumps contain a richer source of ore than the low quality virgin resources that we’re now left with underground. I think we're going to see a lot more “mining” of above ground dumps, which will have the benefit of providing us with the kind of metals that we need for the renewable energy industry like lithium and nickel but without making more mines to do it and simultaneously dealing with the environmental legacy of the older mining practices.
“Water Innovations Market Demand Analysis in the Mining Sector” Report to the Water Research Commission, South Africa by Jo Burgess and Caroline Wadsworth, is available for download at www.wrc.org.za. Copies are available from Jo Burgess.