Oakland Startup Makes Cleaner Cement and Critical Minerals

Imagine solving two massive industrial problems with one ingenious process.

That's exactly what Brimstone, an Oakland-based startup, is doing by rethinking how we make cement and extract critical minerals. The company has developed a revolutionary approach that slashes cement emissions by 60% while producing materials essential for aluminum, steel, and more from a single type of rock.

Here's how it works: Instead of using standard limestone, which releases massive amounts of carbon dioxide when heated, Brimstone uses silicate rocks. This simple switch tackles a huge problem since traditional cement production accounts for about 8% of the world's carbon pollution.

But Brimstone didn't stop there. The same process that creates cleaner cement also extracts valuable materials hiding in those silicate rocks. In early 2025, the company revealed it could produce smelter-grade alumina, the raw material for aluminum. Then came another surprise: the ability to extract steel, magnesium, and titanium from the same rocks in a single refinery.

CEO Cody Finke says these materials represent a $2.4 trillion global market. More importantly, the process offers America a path to produce goods currently made mostly in China, reducing dependence on imports while creating domestic jobs.

The environmental benefits extend beyond carbon reduction. Manufacturing all these materials from the same rock in one mining process requires dramatically less energy and produces far less waste than creating them separately. It's efficiency and sustainability working hand in hand.

The Ripple Effect

Brimstone has already secured commercial agreements with major players. Retail giant Amazon will purchase cement from the company, while Century Aluminum, one of America's largest aluminum producers, has signed on for alumina supplies.

The company earned third-party certification for its Portland cement process in 2023, meaning its product qualifies for standard construction projects. That's a critical milestone proving Brimstone's cement meets industry standards.

The startup's first commercial demonstration plant in Reno, Nevada, is scheduled to begin operating in 2028. This facility will produce cement, supplementary materials, and alumina as proof the technology works at scale.

While Brimstone still faces the challenge of financing and building its first full-scale factory to deliver all promised materials, the progress so far shows real momentum. The company continues working with government officials to secure funding and support for expansion.

Even if Brimstone achieves only part of its ambitious vision, cutting cement emissions by 60% would represent a massive climate win. And if the company succeeds in revolutionizing mineral extraction too, it could reshape American manufacturing for decades to come.