Nucor didn’t disclose the size of the investment, but said the process being developed by Colorado-based Electra has the potential to be a game-changer.  

"We are excited to partner with Electra and its revolutionary process to produce emission-free iron," said Nucor chairman and chief executive Leon Topalian.  

"Just as Nucor changed the face of the steel industry 53 years ago with our first electric arc furnace, successfully developing and scaling up a zero-carbon iron product is the type of transformative technology that could change the steel industry as we know it."

The Electra process electrochemically refines iron ore into pure iron at 60°C, or 140°F, using renewable electricity. The company in October announced that it had raised US$85 million and will complete the build-out of a green-iron refining pilot plant this year at its headquarters in Boulder, Colo., USA. 

It is aiming to have a commercial-scale demonstration plant qualified by the second half of this decade. 

"We are focused on investing our capital on opportunities like these that have the potential to take our company and the entire industry to the next level," said Nucor executive vice president of raw materials Doug Jellison, who has joined Electra's market advisory board. "We will continue to look to the future for new and innovative ways to help our customers achieve their sustainability goals.