Minnesota nickel mine project gets $6.2M infusion to study carbon storage

Rio Tinto and the federal government will together put up $6.2 million to study the potential of a carbon storage project that would accompany a proposed Minnesota nickel mine.

Rio Tinto, an Anglo-Australian global mining giant, is a partner with Talon Metals in the Tamarack mine project in Aitkin County. The mine, which is still in the earliest stages of permitting, would be one of only two primary nickel mines in the United States.

Talon and Rio's pitch for the mine includes a "direct air" carbon capture system, which would suck CO2 from the air and permanently store it in rock waste from the mine. It's a promising technology, but one that is expensive and in its infancy.

The U.S. Department of Energy on Monday awarded $2.2 million to a Rio Tinto-led team of researchers to study storing carbon dioxide underground at the Tamarack site. They will specifically look at how carbon "mineralizes" — or turns to rock — once stored.

Rio Tinto will contribute $4 million to the three-year research project, on top of its other investments.

Researchers on the project include members of the Energy Department's Pacific Northwest National Laboratory (PNNL), which has demonstrated carbon mineralization technology in Washington state; Columbia University; and Carbfix, which is behind a pioneering direct-air-capture carbon capture project in Iceland.

"Rio Tinto has assembled a uniquely qualified team of scientists and innovators to explore new approaches to harness carbon mineralization as a way to safely and permanently store carbon," Talon Metals CEO Henri van Rooyen said in a statement.

Talon is the majority owner and operator of the Tamarack project in a joint venture with Rio Tinto.

Rio and Talon last year announced they were working with California-based Carbon Capture, which is developing a technology that would directly remove CO2 from air. Rio Tinto has also invested $4 million directly in that company.

CO2 removed from the air by Carbon Capture's machines would be mixed with mine tailings-and-cement concoction before it's stored underground.

The magnesium-rich rock that often accompanies high-grade nickel deposits naturally reacts with carbon dioxide, turning it into rock. This happens over thousands of years. The goal with direct carbon capture is to greatly accelerate that mineralization process.

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