A federal court in Arizona last week turned down a request to halt construction of the Hermosa Critical Minerals Project in southeastern Arizona, the Justice Department said November 10. The U.S. District Court for the District of Arizona denied a motion for a preliminary injunction. The Washington Tribune reports environmental groups asked for the pause.

The department says the project will create a domestic source of manganese and substantially increase domestic zinc production. Both metals go into the steel used in military vehicles and naval vessels. In battery-grade form, manganese also goes into the advanced lithium-ion batteries that power unmanned aerial vehicles, radios and other defense equipment. The United States imports all of its manganese and almost all of its zinc, and China holds about 95% of global refining capacity for manganese used in advanced batteries, the department says.

Principal Deputy Assistant Attorney General Adam Gustafson of the department's Energy and Natural Resources Division said manganese is indispensable to national defense and the country cannot stay dependent on foreign supply chains. He said the ruling lets work go ahead on the only domestic project positioned to produce battery-grade manganese, and that the department will keep defending agency actions that restart domestic production of critical minerals.

The U.S. Forest Service approved the project in July 2026 after roughly three years of environmental review, the department says. The project expands existing mining on private land onto the Coronado National Forest. The approval came with consultation with the Fish and Wildlife Service under the Endangered Species Act and more than 400 binding design features, mitigation measures and other conditions to limit environmental harm. The Department of War awarded the project $20 million under the Defense Production Act, and the Department of Energy awarded $166.2 million.

Two environmental groups challenged the agencies' decisions in late October and asked the court to stop the project while the case went on. The court denied that motion because the plaintiffs had not shown they were likely to win their claims, the department says. The court also found a substantial public interest in a domestic supply of critical minerals and said national security interests were relevant and substantial.

Approved work can now proceed while the court weighs the merits on an expedited schedule, the department says. The Washington Tribune notes the ruling does not settle the environmental challenge itself, and later briefing or an appeal will shape how the case goes from here.