Electra has raised $76.3 million to clean up the dirty ironmaking industry, TechCrunch has learned.

The startup has developed a novel method of using electricity to coax pure iron out of low-grade ores, opening the door to cleaner steel. The new funding round, which was disclosed in a regulatory filing, seeks to raise a total of $256.7 million.

Iron production today is highly polluting. It’s responsible for the vast majority of emissions for steelmaking, which itself generates 7% of the world’s carbon emissions. The main process used to make iron today — melting ore in searing-hot blast furnaces driven by burning fossil fuels — has remained largely unchanged for centuries.

As the industry has sought to clean up its act, it has started looking for alternatives. Electra’s solution, known as electrowinning, is already used to produce other metals like copper and nickel. Electrowinning uses an electric current to draw a metal out of a liquid solution. The metal gets plated onto an electrode while impurities drop to the bottom of the tank.

But adapting electrowinning to iron has been challenging, in part because it usually requires higher-grade ores, making the end product too expensive to compete with blast furnaces.

Electra claims that its acid-based process can handle lower-grade ores. It heats up the solution to about 60 degrees C, which is below the boiling point of water, and then sends a current through it. The resulting plates are ideal feedstock for electric-arc furnaces, which can also run on renewable energy.

When combined, electrowinning and electric-arc furnaces have the potential to eliminate the majority of steelmaking’s carbon emissions.

Electra last raised $85 million in 2022 from investors including Amazon, Breakthrough Energy Ventures, BHP Ventures, and Nucor.

The company did not immediately reply to a request for comment.