“Microbes are the world’s oldest miners,” says Liz Dennett, founder and CEO of the start-up Endolith Mining, based near Denver, Colo. “They’ve had billions of years to become incredibly good at eating rocks.”
Scientists at Endolith and elsewhere are engineering microbes to get even better at this process, called biomining—to work faster, extract more copper and even pull out other kinds of minerals. Endolith tests different microbes to see which are most fit for the job and then exposes them to harsh conditions to further strengthen them. “Think of it like a superhero training camp,” Dennett says. In May the company’s engineered microbes demonstrated copper extraction superior to microbes found in nature; its first field deployments are scheduled for later this year.
Biomining, if it can be scaled up, could make it possible to decrease reliance on global supply chains, which are becoming ever more fragile. “If we can make biomining work, we can break the monopoly that states like China have on critical metals,” says Buz Barstow, a biological and environmental engineer at Cornell University. Barstow is leading a project called the Microbe-Mineral Atlas that catalogs microorganisms, their genes and how they interact with minerals. The project’s goal is to build genetically engineered microorganisms that can effectively mine critical metals.
The metal is coming from Gunnison Copper’s Johnson Camp mine, where excavation stopped in 2010 when the previous owners reached ores that weren’t rich enough to profitably process. It is being restarted in partnership with Rio Tinto’s RIO Nuton venture, which uses microbes to strip copper from ores that are otherwise uneconomical to mine.
Advances in mining technology, insatiable demand for the metal that is essential to everything electric, and President Trump’s push to boost U.S. raw-material outputhave made it worthwhile to revisit old mines and marginal deposits around copper-rich Arizona.
Johnson Camp is one of several copper projects racing to production in the state. Most plan to use heap-leaching technologies to produce ready-to-use slabs of copper, called cathodes, without expensive and energy-gobbling concentrators, smelters and refineries.
The U.S. has plenty of copper in the ground, but smelting capacity is a pinch point. A big chunk of U.S. mine output is shipped abroad and sent back in processed forms that manufacturers can use.
“About 50% of our total consumption is being imported because we’re not making enough,” said Craig Hallworth, Gunnison’s finance chief. “This could go a long way to fixing that.”
Gunnison started selling cathodes made using conventional heap-leaching methods of Johnson Camp’s oxide ores in September. The first batch of copper extracted from its sulfide ores using the Nuton technology is expected in the coming days. Ramped up, Johnson Camp should annually produce 25 million pounds of cathode.
Nuton’s approach to copper mining is game-changing. “Our process is more cost-effective and better for the environment compared to traditional methods mining this ore type.” Moving away from traditional, high-energy-use methods, the Nuton® Technology employs a proprietary biological process using specially curated microorganisms to extract copper from ore.
Massive bioreactors serve as breeding grounds where Nuton’s microbes are born to mine. The facility encompassing the bioreactors – the BIGF for short – is the star bioreactor at Johnson Camp Mine where the microbial magic happens.
“It’s like a maternity ward of microbes, where we provide the incentive and conditions to multiply the right microbes at a maximal rate,” Peter says. These microbes work by “eating” ore components such as iron in the ore, which through a series of chemical reactions releases copper in a process that’s as fascinating as it is revolutionary.
Love the idea of biological mining. Do not worry, much, that there will be a doomsday escape of planet eating bugs. Do worry about the term leaching as Cyanide is the only solvent I know.