Antofagasta-owned Twin Metals has moved to defend its mineral leases in north-east Minnesota from “unlawful federal agency action”.

The company on Friday filed a notice of appeal in the US Court of Appeals, following the dismissal of its lawsuit by a US District Court judge last month.

Judge Christopher Cooper in Washington, DC, in September dismissed Twin Metals’ 2022 lawsuit, which challenged the US Interior Department’s earlier decision to cancel leases for an underground mine near the Boundary Waters Canoe Area Wilderness.

The Interior Department cancelled the leases and other mining approvals after determining they were illegally renewed despite US Forest Service objections related to concerns that mining could pollute the wilderness's streams and lakes with potentially toxic waste.

According to a report by Reuters, Cooper said his court lacked jurisdiction over Twin Metals’ claims under the Administrative Procedure Act, because the rights allegedly violated by the government stemmed from the terms of its leasing contract with the US government – not procedural legal rights outlined in that law. He reportedly said the claims should have been brought under the Tucker Act, which allowed parties to sue the US over contractual disputes involving the government.

“Twin Metals is committed to securing its federal mineral rights, which are essential to our transition to a clean energy future,” chief project officer of Twin Metals Minnesota, Francisco Awad, said in a statement on Friday.

“The team at Twin Metals is shaping the future of sustainable mining while championing environmental responsibility. We can both safely mine for critical minerals and protect our environment. Let’s allow for the environmental review process to demonstrate that,” he stated.

Awad pointed out that Twin Metals had spent more than 13 years in northeast Minnesota conducting environmental, engineering, exploration, hydrogeological and community engagement work.   

Meanwhile, Twin Metals last week reported that the Minnesota Department of Natural Resources had authorised its exploration plan on a limited number of existing state and private mineral holdings.

The goal of the exploration activity is to better understand the company's mineral resources and its potential to contribute critical minerals to support Minnesota and the nation, explains Dean DeBeltz, Twin Metals VP of external relations and project operations.

The state and private mineral leases targeted for the exploration work are held under Twin Metals’ subsidiary company, Franconia Minerals, and the plan encompasses up to nine drill holes for the purpose of collecting core samples.

DeBeltz adds that all activities that take place as part of the exploration work will comply with the applicable state and federal regulations, as will the closure and reclamation activities. Targeted areas for the drilling programme are not under Birch Lake, and all drill sites are located on private land.