Breaking: Boston Metal Raises $75M for Critical Metals Push
Boston Metal has secured $75 million in new funding to scale production of critical metals, MIT Technology Review learned exclusively. The startup, best known for its green steel technology, is now prioritizing higher-value metals like niobium, tantalum, vanadium, nickel, and chromium.
The investment comes after a cash-flow crisis triggered by an industrial accident at its Brazil facility earlier this year. The company missed a key milestone and laid off 71 employees in April.
Background
Boston Metal’s core technology is molten oxide electrolysis (MOE), which uses electricity to separate metals from ore at 1,600 °C. The company has long targeted the steel industry—responsible for 8% of global emissions—but now faces waning US support for industrial decarbonization.
A subsidiary in Brazil is building a commercial facility to process low-grade material into critical metals. Construction started in 2024, but a leak in the plant’s refractory system in January caused delays and electrolyte leakage. CEO Tadeu Carneiro said there were no injuries or environmental damage.
What This Means
The funding ensures Boston Metal can restart operations in Brazil and continue piloting its MOE technology for steel. “Because of this delay, we had a big stress in our cash flow, so the investors came very strong to support us,” Carneiro told MIT Technology Review.
By focusing on critical metals—used in jet engines, MRI scanners, and electronics—the startup can command higher prices and strengthen its balance sheet. This pivot may also position it as a domestic supplier of materials essential for aerospace, defense, and clean energy, reducing reliance on foreign sources.
The Technology in Action
MOE works by running electric current through a reactor filled with ore dissolved in a molten electrolyte. The heat drives chemical reactions, and pure metal collects at the bottom for extraction. In early 2025, Boston Metal completed its largest test run in Woburn, Massachusetts, producing about a ton of steel.
The Brazil Incident
In January, a refractory failure caused electrolyte to leak from the Brazil plant. Operators shut down the system safely. But the delay meant Boston Metal missed funding triggers tied to milestone completion, leading to the April layoffs. The new $75M round will support the plant going forward.
Looking Ahead
If successful, Boston Metal could disrupt both the steel and critical metals markets with a cleaner process. The company is also exploring production of vanadium and chromium for alloys. Carneiro emphasized that the Brazil facility is now on track to demonstrate industrial-scale viability.
Investors include a mix of existing backers and new strategic partners, though details remain confidential. The round closes as global demand for critical minerals surges for EVs, wind turbines, and electronics.