The American Exploration & Mining Association was joined by a coalition in filing a challenge last Friday in the Wyoming district court.
The world’s largest producer of uranium is increasing its mining tax on the nuclear fuel by at least 50% next year.
Portugal already has the largest copper mine in the European Union, operated by Lundin Mining.
Oversupply and weak prices of materials such as lithium, cobalt and rare earths are dampening cash flows of Western start-ups.