Green steel startup Boston Metal is doubling down on critical metals

Boston Metal has raised $75 million after a rough stretch that included an industrial incident and laying off 71 employees earlier this year. The company is shifting focus to critical metals like niobium, tantalum, and chromium, which command higher prices and could help prove its technology before returning to steel. Its commercial facility in Brazil, delayed by an electrolyte leak in January, is now being repaired and is expected to start up in September 2026.

The round includes support from Tata Steel, one of the world's largest steelmakers, bringing Boston Metal's total funding to over $500 million. " data-chronoton-post-id="1137523" data-chronoton-expand-collapse="1" data-chronoton-analytics-enabled="1"> The startup Boston Metal has raised a $75 million funding round to produce critical metals, MIT Technology Review can exclusively report. The company has been known largely for its efforts to clean up steel production, an industry that’s responsible for about 8% of global greenhouse emissions today. With the additional money, the new focus could help it survive at a time when support for industrial decarbonization has been waning in the US. In addition to steel, Boston Metal has also worked to use its technology with other metals, and a subsidiary (Boston Metal do Brasil) is setting up a commercial facility in Brazil to produce niobium, tantalum, and tin. The funding will help support that facility’s operation as well as future efforts to produce critical metals like vanadium, nickel, and chromium, says CEO Tadeu Carneiro. The funding comes after the company faced cash-flow problems following an industrial accident at the Brazil facility earlier this year. Boston Metal’s core technology is called molten oxide electrolysis (MOE). It involves running electric current through a reactor filled with ore dissolved in a molten electrolyte. The electricity heats everything up to about 1,600 °C (3,000 °F) and drives chemical reactions that separate the desired metal (or metals) from the ore. The metal gathers at the bottom of the reactor, where it can be siphoned off. In early 2025, Boston Metal completed the largest run of its pilot industrial cell in Woburn, Massachusetts, producing about a ton of steel.

Key points

• The round includes support from Tata Steel, one of the world's largest steelmakers, bringing Boston Metal's total funding to over $500 million.
• " data-chronoton-post-id="1137523" data-chronoton-expand-collapse="1" data-chronoton-analytics-enabled="1"> The startup Boston Metal has raised a $75 million funding round to produce critical metal…
• The company has been known largely for its efforts to clean up steel production, an industry that’s responsible for about 8% of global greenhouse emissions today.
• With the additional money, the new focus could help it survive at a time when support for industrial decarbonization has been waning in the US.
• In addition to steel, Boston Metal has also worked to use its technology with other metals, and a subsidiary (Boston Metal do Brasil) is setting up a commercial facility in Brazil to produce niobiu…