Nextgen miners might include microbes

Each year in Canada, roughly 200 active mines contribute to billions of tons of mining waste. The estimated number of tailing storage facilities surveyed worldwide is over 12,000.

While considered industrial waste, these facilities also contain a number of useful minerals at a concentration deemed too low to be worth extracting-until now.

Enter biomining, which covers several biological separation technologies offering eco-friendly recovery of valuable and strategic materials using special enzymes and bacteria. Specifically, these methods use microorganisms to replace conventional chemicals traditionally used to extract metals from ores, further process tailings or remediate mine sites.

Various toxic chemicals, including sodium cyanide, mercury, selenium, and lead, are commonly employed or produced in ore extraction. With strict practices like the Global Industry Standard on Tailings Management being implemented across the industry, mining agencies large and small have been on the hunt for natural, more efficient ways to extract and process minerals at every stage.

Slowly growing

Biomining was first introduced in the 1950s as less energy-intensive and potentially cheaper than traditional mining to squeeze more valued minerals like copper from low-grade deposits and the waste products of existing mines.

Now, proponents of biomining herald its potential is finally being realized on a grander scale, proving critical to the green energy transition while helping companies and nations meet their emissions reduction goals.

"We talk about the climate crisis. We've actually got a mining crisis or metals crisis," said John Steen, director of the Bradshaw Research Initiative in Minerals and Mining for the University of British Columbia.

It has been estimated that in transitioning to green energy technologies, demand for copper is expected to roughly double between now and 2035 with industries requiring more in the next three decades than the entire world has consumed in the last 120 years.

Copper is only the beginning. Several minerals previously considered less important byproducts have been driven into heavy demand for making green energy products, the biggest consumers being rechargeable batteries from phones to cars, solar panels, wind turbines and generators.

Prime targets of expanded biomining extraction include rare earths, lithium, cobalt, nickel and zinc-all of which can be extracted out of a diverse collection of overlooked resources from geothermal to bauxite tailings.

The only challenge is how quickly biomining can be scaled up to meet soaring demand.

According to the market research and consulting firm Credence Research, biomining has generated a (comparatively paltry) total of $1.5 billion for mining companies in 2020, with expected growth to $3.6 billion by 2027.

With the U.S. global mining industry valued at an easy $2 trillion and growing, there's potential for biomining to transform into the industrial standard for large-scale mine site remediation and reclamation with increased payoffs and green credential appeal.

Teaming up

Microbes work best in a consortium, a mixed community with different species offering cooperative functions to break down elements into component parts that are less harmful and of better use.

To understand what's possible, scientists gather samples from mine sites and use DNA sequencing and genome mapping to identify microbes that perform with naturally produced proteins – what chemicals were previously employed to do artificially. The information is then used to engineer consortiums that can extract specific ingredients from mining waste, from contaminants to desired metals.

For example, microbial remediation of a tailing pond containing compounds of sulfur and iron could break the slurry down into more usable states: the iron particles could be isolated, sulfur converted into gypsum, with the neutralized sandy materials remaining used as mine backfill.

Until recently, biomining operations lacked an efficient way of sharing the information they learned about microorganisms' genetic material at each mine site with other specialists around the world.

In early 2022, the Digital Technology Supercluster, led by major industrial partners, genome research centers and mining giants launched The Mining Microbiome Analytics Platform (M-MAP) knowledge exchange platform.

M-MAP, for which Steen is a vocal spokesperson, contains pre-existing information from public archives and invites participating scientists, engineers, and other specialists to send in samples from mining sites around the world to grow a library for genetic sequencing and analysis used to inform biomining processes and the like.

Other partners in the project include Teck Resources and Rio Tinto, Microsoft, the University of British Columbia, BC Ministry of Energy, Mines and Low Carbon Innovation, BGC Engineering, the Centre for Excellence in Mining Innovation, Koonkie Canada, Genome BC, Allonnia, and Illumina.

"You think about the mapping of the human genome that started nearly 20 years ago and all the advances that have been happening in medicine because we understand the human genome," Steen said. "This microbe genome project, with all the microbes around the mines, it's quite similar. It will just accelerate the way that we develop technologies for a whole range of different challenges in mining-from exploration through the mineral processing and especially the waste that we generate."

As gene-sequencing technology becomes increasingly affordable, projects like M-MAP and related technologies are pushing forward in leaps and bounds. With every site being unique, shared information can help fine-tune microbial consortiums for building processes around the specific needs of particular mining sites, or whole industries.

Money still talks

The long-term success of biomining still comes down to the bottom line. "The prices that we'll see in metals over the next twenty years will sustain a new industry in mining waste," says Steen. "When the economy feels the pain of high metal prices, that's when we develop innovations to do it cheaper and better."

That pressure is already here, demonstrated by some mining companies pushing for deep-sea mining despite intense pushback from a surprising number of industry leaders alongside conservationists.

M-MAP's database will be available for free to a range of researchers applying the decoded information to other industrial fields, from extraction to carbon dioxide sequestering. Microbial tools and genetic information are already key to several new technologies in the fuel, forestry, agriculture, and wastewater treatment industries.

Projects based on goodwill and information sharing like M-MAP will be necessary to support the worldwide energy transition and carbon reduction goals, accelerating solutions like biomining and related innovations fostered by the free profusion of data.

"There'll be nothing else in the world that's as powerful as this, and it will just get more and more powerful," said Steen.

CORRECTION 11-13-27: This article was updated to correct an inaccurate characterization of Allonnia, a bioinformatics/synthetic biology company working on environmental solutions.