Ceibo unearths $30M Series B to extract more copper out of existing mines

When it comes time to fret about minerals critical to the energy transition, lithium, cobalt and nickel may get all the attention, but another metal is keeping plenty of analysts up at night.

Though those other minerals are key ingredients for batteries, copper is used across every sector that will be touched by electrification. Transmission wires, electric motors, inverters and battery packs all rely on the 29th element.

“There’s no energy transition, no decarbonization without some critical minerals,” Ceibo CEO Cristóbal Undurraga told TechCrunch+.

But less than a decade from now, demand for copper is expected to outstrip supply by 6.5 million metric tons, according to McKinsey. That portends a 25% shortfall.

One answer to that dilemma is to find more copper buried in the earth and dig it up. But that costs a lot, takes a ton of time and damages the environment. A better approach is to extract more copper out of the mines we have today.

There are several ways to do that — bacteria is an option; more on that later — but the one that helped Ceibo dig up a $30 million Series B relies on tweaking a century-old process. The round was led by Energy Impact Partners with participation from existing investors Khosla Ventures and Aurus Ventures and new investors including CoTec Holdings, Audley, Orion Industrial Ventures, Unearth Capital and Pincus Green.

A significant fraction of today’s copper is extracted by heap leaching. Rock containing copper ore is heaped into a pile and sprinkled with acid. As the acid trickles down through the pile, it strips some of the copper ore out of the rock. A basin at the base of the pile collects the acid-ore mixture, from which pure copper is extracted. It’s not the most environmentally friendly operation, but it uses less water and land than the alternative.

One of heap leaching’s main drawbacks is that it only works on certain types of copper ore. Much of the copper ore dug from deep underground is of a type known as sulfides. Historically, heap leaching wouldn’t work on this type.

Ceibo has developed an additive to the acid that works on copper sulfides. As a result, mine operators who exhaust their easier-to-refine ores don’t have to build expensive facilities that would otherwise be needed to tackle the remaining sulfide ores. A few other companies are taking a similar approach.

That makes it sound easy, but it’s not. The chemistry is challenging, sure, but the harder part is getting a foot in the door with mining companies, which are notoriously conservative and hesitant to try new techniques. “If you show up in a white coat, trust me, they’re not gonna let you in the door,” Undurraga said.

To get inside, Ceibo started by selling a dust suppressant and, eventually, a dust-suppression service. Mines, as you can imagine, kick up all kinds of dust, putting them in peril of angering the neighbors and violating their operating permits. The mining companies could spray water to keep it down, but many mines run in dry regions. So Ceibo’s first offering promised to suppress 80% of a mine’s dust and reduce water usage by 50% to 70%.

The dust suppression product “gives us some visibility,” Undurraga said. “It also gives us some credibility, and it gives us some cash.”

From there, the company started working on its leaching additive, which it’s announcing today. It has also continued work on another, more intriguing technique involving bacteria. In fact, bacteria were always part of Ceibo’s vision. “We started some years ago trying to understand if we could use this bacterial approach,” he said. “We discovered that yes, you can. But it’s going to take a lot of time to get scientifically.”

The bacteria can be used in a range of applications, including on traditional heaps. But they can also be injected underground to digest the copper sulfates and be pumped back to the surface, copper in tow. Such an approach would minimize a mine’s surface disruption, though it would also pose risks to groundwater supplies.

Currently, the main technical challenge is wrangling bacteria in an open and uncontrolled environment. While bacteria live everywhere on Earth, coaxing them to do something extraordinary — like efficiently extracting copper deep below ground — usually involves some trade-offs. Bacteria may not thrive in those conditions, and those that do might not do the job quickly or effectively. Eventually, those trade-offs could be minimized, but it’ll take time.

In the meantime, Ceibo is going to be using its Series B funding to transition from a dust-suppression company to one that helps mines recover more ore. So far, its phased go-to-market approach has helped build the business to a point where it has a reliable revenue stream. It was a deliberate decision, said Undurraga, who experienced the clean tech boom and crash in the early 2000s.

Cautious scaling isn’t usually what startups prioritize, but in this case, it seems to be the right decision — one that’s helped the company land a significant round with some solid investors. Next up: executing on the transition. If Ceibo can nail it, the looming copper shortage may not be so worrisome.