US blocks mining in parts of Minnesota, dealing blow to Antofagasta’s Twin Metals copper project

Interior Secretary Deb Haaland signed an order on Thursday withdrawing 225,504 acres in the Superior National Forest from leasing to mining or geothermal companies through 2043.

In 2019, Chilean miner Antofagasta, through its subsidiary Twin Metals, carried out a feasibility study for the project, an underground copper-nickel mine and processing facility along the shores of Birch Lake and the South Kawishiwi River, which lie in the Rainy River watershed.

A coalition of businesses, environmental advocates and outdoor recreation groups in the state of Minnesota went to court challenging a Trump administration’s decision that opened the door to a copper, nickel and platinum project by a wilderness area.

In August 2022, Antofagasta Plc’s Twin Metals subsidiary sued the US government in a bid to revive the proposed Minnesota copper and nickel mine, which Biden administration officials had blocked over concerns it could pollute a major recreational waterway.

Twin Metals asked the US District Court in Washington to restore the leases, which were first granted in 1966 and have been passed between successor companies. No mining has taken place at the site.

The underground mine would, if built, be a major US source of copper and nickel, two metals crucial for the green energy transition. The only existing US nickel mine is set to close by 2025.