A US judge has rejected a bid by Twin Metals, a subsidiary of Chilean mining company Antofagasta, to restore the cancelled mining leases for the Minnesota copper and nickel mine, worth $1.7bn.

If approved, the project would have been one of the US’s largest resource pools for metals needed for the green energy transition.  

In 2022, Twin Metals filed a lawsuit that challenged the decision of the US Interior Department to cancel leases for an underground mine near the Boundary Waters Canoe Area Wilderness. On Wednesday, US District Judge Christopher Cooper dismissed the lawsuit. 

In January 2023, the Biden administration had blocked mining in part of northeast Minnesota for 20 years, over concerns it could pollute a major recreational waterway and also harm the state’s vast network of interconnected waterways. 

The Interior Department determined that the leases were illegally renewed despite the US Forest Service objecting over concerns that mining could pollute the streams and lakes with potential toxins.  

In its lawsuit, Twin Metals said in August 2022 that the company had spent hundreds of millions of dollars to develop a "state-of-the-art, environmentally sound mine,” reported Reuters. The director of operations and safety at Twin Metals, Dean DeBeltz, had added, "Our leases were illegally cancelled by the government, and we want to stand up for what's right and what's prescribed by law."  

The leases for mining were granted in 1966 and have since passed along without any actual mining taking place on the site. 

Twin Metals had acquired the leases in 2011 and was to renew those in 2012. However, the request was denied in 2016 when the Obama administration said they had the discretion to deny the lease renewal since no mining activity had begun.  

In 2019, the Trump administration reversed the order and renewed the leases, which were again cancelled in 2022 by the Biden administration.