This story was first published by Grist.
At a laboratory in Newark, New Jersey, a gray liquid swirls vigorously inside a reactor the size of a small watermelon. Here, scientists with the mining technology startup Still Bright are using a rare metal, vanadium, to extract a common one, copper, from ores that are too difficult or costly for the mining industry to process today.
If the promising results Still Bright is seeing in beakers and bottles can be replicated at much larger scales, it could unlock vast copper resources for the energy transition.
Still Bright isn’t the only company seeking to revolutionize copper production. A handful of startups with similar goals have announced partnerships with major mining firms and scooped up tens of millions of dollars of investment. These companies claim their technology can help meet humanity’s surging appetite for the metal, while driving down the industry’s environmental footprint.
“We’re facing unprecedented demand for copper, and that’s really tied to the electrification of everything,” Still Bright chief of staff Carter Schmitt told Grist.
The world cannot reach its climate goals without copper, which plays a central role in the technologies needed to decarbonize. Copper wiring is at the core of the world’s electricity networks, which will have to expand enormously to bring more renewable energy online. Wind turbines, solar panels, electric vehicles, and lithium-ion batteries all rely on the mineral, too. As the market for these technologies grows, the clean energy sector’s demand for the 29th element is expected to nearly triple by 2040.
At the same time, copper miners are exhausting their best-quality reserves. Copper that is economical to mine is found in rocks known as ores, and grades of the ores that miners are exploiting — the concentration of copper contained in them — have declined steadily over the past 20 years. Meanwhile, easy-to-process minerals near the surface are giving way to more challenging ones deeper down. And the current standard procedure for extracting the metal from the majority of ores results in a lot of pollution.
About 80 percent of the copper mined today comes from unweathered rocks known as primary copper sulfide ores. After being crushed and ground to a fine powder, the copper inside primary sulfide ores is concentrated using chemicals before being sent to a smelter, where it is refined at high temperatures.
The process of concentrating and smelting copper produces a toxic mineral slurry called tailings, and a cocktail of air pollutants including lead and arsenic. In the United States, a single Native American tribe — the San Carlos Apache people — has borne the brunt of that pollution. Two of America’s three copper smelters are located within a few miles of the tribe’s reservation boundaries in southeastern Arizona. Both are among the worst lead emitters in the nation, spewing toxic metals into the air for the better part of a century. (One of these smelters was mothballed four years ago following a labor strike, but is reportedly planning to resume operations to meet surging copper demand.)
“This stuff doesn’t go away,” says Jim Pew, the director of clean air practice at the environmental law firm Earthjustice, told Grist. “It falls back to the Earth and permanently contaminates the communities nearby.” (The San Carlos Apache Tribe didn’t reply to Grist’s request for comment.)
In addition to air pollutants, copper smelters are energy intensive and typically require fossil fuels, driving up costs as well as carbon emissions. If the ore is too low-grade (meaning the concentration of copper is too low) companies simply can’t get enough out to cover the cost of extracting it.
But globally, low-grade primary sulfide ores contain enormous amounts of copper. A March report by Goldman Sachs estimated that the world’s top five copper miners are sitting on “billions of tons” of such ores — an amount that makes the expected 5 to 6 million ton copper supply shortfall over the next decade look puny.
“It’s not that the world is out of copper,” Cristobal Undurraga, CEO of the Santiago, Chile-based startup Ceibo, told Grist. “It is, though, in a form … harder to extract using traditional processes.”
Founded in 2021, Ceibo is one of several mining technology startups that’s proposing a new, old approach to getting copper out of low-grade sulfide ores: a process known as heap leaching. Heap leaching is already used to process the weathered rocks located toward the top of most deposits, which account for about 20 percent of copper mined today. Miners process these rocks on site by crushing the rock, piling it up into a heap, and spraying it with acid, which percolates through the rock and liberates the valuable metal. The process produces significantly less pollution and carbon emissions than traditional copper smelting — but until recently, no one has figured out how to make it work efficiently for primary sulfide ores.
Ceibo claims it is able to recover large quantities of copper with a chemical extraction approach that involves altering critical conditions in the crushed ore, such as the pH and oxygen concentration, making it easier for the acid to get to work. Ceibo says its process is flexible and can accommodate the wide variety of geologic and environmental conditions a company might encounter in different parts of the world — or even different parts of the same subterranean pit. “What we are developing is a whole geological platform” that can be adjusted based on those changing conditions, chief technology officer Catalina Urrejola told Grist.
Ceibo hasn’t revealed many details of its process, which it has mostly tested at the laboratory scale. But the firm has already secured $36 million in venture capital financing to scale up, including funding from major industry players like BHP Ventures, the investment arm of one of the world’s largest copper producers. In November, Ceibo began its first pilot tests with Glencore’s Lomas Bayas Mining Company, based in Chile’s Atacama Desert.
