Apr 5, 2024

I’ve written (and read) a lot over the past year about biomining; leveraging microbes to improve the outcomes from mining processes. Applications extend from the preconditioning of orebodies and enhancing metals recovery through synthetic biology, to the remediation of acid mine drainage, and more. The opportunities that these tiny microbial miners present across the asset lifecycle are huge, and there are some amazing startups working in this space, pushing the boundaries of science, like Jetti Resources , Koonkie and Cemvita , to name a few. Liz Dennett is CEO of Endolith and CTO at Cemvita Cemvita, which has long been a friend of The Intelligent Miner, recently launched a spin off company called Endolith ; endoliths are microorganisms that live inside rocks or in the pores between mineral grains, in case you were wondering. Dr Liz Dennett , Cemvita’s Chief Technology Officer, has stepped into the role as Chief Executive Officer for Endolith, and she was introduced to me by a mutual acquaintance as “an Alaskan astrobiologist who used to work for NASA”. I’m a sucker for an interesting resumé and, with a recommendation like that, an interview invitation was immediately on the table. “How does an astrobiologist come to be the CEO of a biotech company working in the mining space?” I asked Dennett when we sat down for a virtual interview a couple of months later. “I grew up in rural Alaska, and people there are tenacious and independent spirits,” she explained. “My dad was a geologist and he instilled in me a deep connection to the natural world and its resources. Mining is a huge part of the Alaskan economy, and with that comes a deep understanding and respect for the land. “Growing up in the middle of nowhere, problem solving was a big part of my life; if my bike broke, I couldn’t go to the store and get a new part to fix it. I had to put something together myself. I always wanted to find new and better ways to do things and that led me to go to grad school for astrobiology.” Dennett specialized in geo-microbiology, exploring how microbes can catalyze broad geochemical cycles on early Earth as a proxy for life on Mars at the NASA Astrobiology Institute [super cool, right?!]. After that, she followed her passion, working mainly in companies linked to natural resources and the energy transition. “I’ve worked in analytics, cloud computing and genomics. I’ve been an oil and gas geologist… Now there’s an urgent need for critical minerals, and there’s huge untapped potential for geo-microbiology, especially in mining. It’s an exciting time, and I felt like I couldn’t sit on the sidelines any longer,” she said. “It’s an honour to jump in the deep end, and to be the CEO of a company that’s looking at harnessing microbes, taking geo-microbiology and the problem-solving attitude I grew up with, and tying them together with some of the latest technologies and approaches to fuel sustainable mining.” Putting a new lens over an age-old process Endolith is a seed-stage start up. The company uses biolixiviants – chemicals produced by microbes – to extract metals from existing reserves or unlock new resources. The team of 14 are forging their own path with Dennett at the helm. Their ideas are smart and, in some cases, quite radical, harnessing cutting-edge technologies to revolutionise biomining. “Biomining has been around a long time,” said Dennett. “But it’s only in the past 5-10 years that we’ve been able to use deep technology to optimise the processes involved. Computing has gotten faster and cheaper, as has DNA sequencing. By combining those two paradigm-shifting technologies, we can better understand the microbes that are present and how to harness them to enhance the extraction of elements from different mineral phases.” The ability to apply emerging technologies and techniques, like adaptive laboratory evolution (ALE), to help microbes adapt to say, increasingly brackish water or high arsenic concentrations, and cloud computing to manage data and perform sophisticated analyses based on machine learning and artificial intelligence (AI), are also proving game changing. Miners have long understood that microbes play an important role in certain operations, but until recently, they haven’t had the tools to sequence them. Image: Unsplash “For me, it’s about taking a knowledge base that’s already there and breathing new life into it with these tools,” Dennett added. “I see technology as the toolset that lets us unpack the information microbes hold and grow our scientific knowledge.” Miners have long understood that microbes play an important role in certain operations, for example, in copper-pyrite heap leaches, but until recently, they haven’t had the tools to sequence them. And it’s not just gaining that knowledge that’s a challenge but also, once it’s obtained, figuring out what to do with it. For instance, do you study organisms and their taxonomy? Do you try to grow them? Do you look at what you could be doing to accelerate oxidative reactions…? The answer is probably all these things, and more. This is where geo-microbiologists and genomics specialists come in. Dennett explained: “In terms of understanding heap leach dynamics, heat flow simulations are critical. Once you’ve got DNA sequences, there are different techniques that can be applied to figure out which genes could be expressed. For those, I’d advise that people go straight to the cloud, and use cloud-native techniques to figure out which microbes are there and what they could be doing. “But there’s also a definitive hands-on role that comes with being an adept microbiologist and growing these organisms. Now, not all organisms can be grown, but for those that can, there’s the opportunity to interrogate them, because not all microbial systems have been well studied. There are still lots of unknowns, and a lot of this work is on the frontline of discovery.” Securing future metals through biomining “What role can biotechnology play in securing metals for the energy transition?” I asked Dennett. “Not just the sexy metals, like lithium and cobalt, but also copper?” “Copper is sexy!” Dennett replied with a chuckle. “It’s probably the sexiest of all the metals. Demand for copper is set to double by 2035 , but most high-grade orebodies have been depleted. That’s a big challenge and the industry also needs to minimise its environmental impact, so we have to get creative. That’s where hydrometallurgical processes like heap leaching come in and microbiology is a huge driver.” Take the example of chalcopyrite heap leaches, microbes oxidise the pyrite which heats up the heap leach and catalyses chalcopyrite oxidation which provides enhanced copper recovery. In other trickier ore types, like copper arsenic, the microbes can be hardy enough to survive very high arsenic environments. “I’ve seen lab experiments, for example, where over 90% copper recovery has been achieved through optimisation of the microbiome,” said Dennett. “That’s huge. Traditionally, miners would use really harsh acids to achieve that which can create both upstream and downstream issues. “Environmental regulations around sulphur emissions are getting tighter, acid prices are increasing, and if there’s any way that miners can offset some of that cost with better recoveries and produce the metals we need, then that’s going to be a big win-win.” At the cutting edge of metals recovery Dennett explained that the secret to unlocking better recoveries lies in sequencing microbial DNA and bringing that data into a platform where it can be compared to those from other microbes (similar to what the consortium of companies behind the Mining Microbiome Analytics Platform is currently working to create). Essentially, the cutting edge of innovation in sustainable mining today exists at the nexus between deep technology and microbiology. “We’re discovering things that have never been discovered before; things that we never even thought we could discover,” said Dennett excitedly. “There won’t be one magic microbe that transforms biomining applications. These systems are incredibly complex, and the better we understand the microbes that are present and the role they play in different processes, the better we can tweak the conditions to maximise copper recovery. For that, we need the power of cloud computing to handle the data and apply AI and machine learning.” Of course, it’s not just about the data and the technology, but also about our human capability to think about and engineer systems. Again, systems thinking wasn’t a core skill in mining 10 or 20 years ago but, today, things are quite different. “It’s an analogue that I’ve seen in a lot of other heavy industries,” Dennett agreed. “Coming from the oil and gas space, five or six years ago, those companies were already exploring how to take seismic or well data into cloud-hosted platforms and use insights from hundreds of different datasets to optimise their recovery. We’ve seen the kind of value those companies have been able to generate for their customers, and I think that’s where biomining is heading too.” That includes the deployment of more real-time sensors and real-time analytics in the field to make smaller tweaks during operations, for example, to things like collection of the pregnant leach solution (PLS) and raffinates, to optimise recovery over the life of the heap leach. Hydrometallurgical processes, like heap leaching, can be important in recovering in recovering lower grade copper ores and microbiology is a huge driver of that. Image: Unsplash Building the heap leach of the future “That’s what I like to think of as the ‘heap leach of the future’,” said Dennett. “Especially in greenfield environments, we have the ability to design heaps from the ground up and optimise for long-term recovery versus short-term economics. “Really it all comes down to applying technology and advances in computing power, DNA sequencing and micro fluidics, as well as trends like decentralisation and miniaturisation, the same way you would in a wind farm where distributed sensing enables predictive maintenance… I suspect we’ll see a lot of the same trends enabling bioleaching and mine optimisation.” “How would the ‘heap leach of the future’ work on a practical level?” I asked. “The reality is that it’s going to take time,” said Dennett. “We need to sit down with mining customers, look at their rocks, infrastructure and techniques, their team and where they want to get to and figure out together how we can systematically move towards that goal. It requires a journey to make sure that we’re designing the right application for their operation. And so that mining companies can leverage the technologies to meet their needs. “In practice, what this looks like, is leveraging data and some of the really cool techniques that we’ve talked about. For example, if we’re looking at a greenfield copper-arsenic development and the economics are challenging, we might use biolixiviants to achieve greater copper liberation. “We can use traditional heap leaching methodologies if that’s what the company wants to do, but there’s a bigger opportunity to deploy in-situ technology, geochemical measurements and DNA sequencing in the field for relatively low cost to make sure that operation is optimised.” The neat thing about copper recovery is that, if you’re able to get even a few percentage points more recovery out of the system, the economics can be massive. Upfront costs are relatively fixed, so anything that miners can do to optimise metal recovery over the life of the asset usually offers a big return on investment. From information to insights Dennett explained that, while it’s relatively easy to do descriptive analyses and present clients with data on spreadsheets or in a dashboard, it’s much harder to provide useful, predictive insights. But ultimately, that’s what empowers companies to take action. “Approaching some of these problems in a data-first way could be really transformative, but we need to provide predictive and tangible actions based upon it,” she told me. “For us, the hardest part of the process is the paperwork and getting access to ore samples. Once the ore is in-house, we can move pretty quickly with test work and deployment. The key is working closely with mining companies. By doing that, we can add real value and fuel sustainable mining.” We ended the call on a high note; Dennett was off to guide Endolith through its latest round of funding with the promise that, the next time we speak there will likely be interesting project news to share. I, for one, will be following the company’s progress closely. Because, going forward, even the tiniest step taken by microbes, could represent a very big leap for the field of biomining. Share this: