“We’re really focused on addressing the copper supply crisis that’s looming ahead of us,” says Randy Allen, Still Bright’s cofounder and CEO.
Copper is a crucial ingredient in everything from electrical wiring to cookware today. And clean energy technologies like solar panels and electric vehicles are introducing even more demand for the metal. Global copper demand is expected to grow by 40% between now and 2040.
As demand swells, so do the climate and environmental impacts of copper extraction, the process of refining ore into a pure metal. There’s also growing concern about the geographic concentration of the copper supply chain. Copper is mined all over the world, and historically, many of those mines had smelters on-site to process what they extracted. (Smelters form pure copper metal by essentially burning concentrated copper ore at high temperatures.) But today, the smelting industry has consolidated, with many mines shipping copper concentrates to smelters in Asia, particularly China.
That’s partly because smelting uses a lot of energy and chemicals, and it can produce sulfur-containing emissions that can harm air quality. “They shipped the environmental and social problems elsewhere,” says Simon Jowitt, a professor at the University of Nevada, Reno, and director of the Nevada Bureau of Mines and Geology.
It’s possible to scrub pollution out of a smelter’s emissions, and smelters are much cleaner than they used to be, Jowitt says. But overall, smelting centers aren’t exactly known for environmental responsibility.
So even countries like the US, which have plenty of copper reserves and operational mines, largely ship copper concentrates, which contain up to around 30% copper, to China or other countries for smelting. (There are just two operational ore smelters in the US today.)
Still Bright avoids the pyrometallurgic process that smelters use in favor of a chemical approach, partially inspired by devices called vanadium flow batteries.
In the startup’s reactor, vanadium reacts with the copper compounds in copper concentrates. The copper metal remains a solid, leaving many of the impurities behind in the liquid phase. The whole thing takes between 30 and 90 minutes. The solid, which contains roughly 70% copper after this reaction, can then be fed into another, established process in the mining industry, called solvent extraction and electrowinning, to make copper that’s over 99% pure.