Rio Tinto (ASX, LON: RIO) has approved a $144 million investment to advance its Resolution Copper project in Arizona, months after securing control of land needed for what could become one of the largest copper mines in the US.
The funding will support feasibility studies and engineering work for mining equipment and water treatment facilities. Rio Tinto will contribute $79 million, reflecting its 55% stake in the joint venture, while BHP (ASX: BHP) will cover the remaining 45%. The companies expect the next phase to create about 50 additional jobs.
“Resolution Copper has the potential to supply up to 25% of America's copper demand for decades, strengthen domestic supply chains and deliver significant economic benefits for Arizona,” Rio Tinto chief executive Katie Jackson said.
The investment underscores Rio Tinto's growing focus on copper as demand rises for the metal used in power grids, electrification and artificial intelligence infrastructure. It also marks another step toward developing a major domestic supply source as the US seeks to strengthen its critical minerals supply chains.
Legal challenges
The decision follows a lengthy legal battle over the transfer of federal land needed for the mine. The dispute pitted the religious rights of the San Carlos Apache people against efforts to develop one of the country's largest undeveloped copper deposits.
Native American groups have opposed the project because of its potential impact on Oak Flat, a site considered sacred by Apache communities. Although Rio Tinto secured control of the acreage, the controversy has highlighted the challenges of balancing mineral development with Indigenous cultural and religious protections.
Located near Superior, Arizona, the copper deposit lies between 5,000 and 7,000 feet (1,524 and 2,134 metres) underground. Rio Tinto has targeted the mid-2030s for the mine's opening, although the development remains subject to further studies and approvals.
The project is estimated to contain more than 40 billion lb. (18.1 million tonnes) of copper, with the potential to support production for decades.