Rio Tinto has approved an investment of $144 million to advance its Resolution copper mine project in Arizona, one of the largest copper mines in the US, months after securing control of the land required for development, according to Mining.com.
The funding will support feasibility studies and engineering for mining equipment and water treatment facilities. Rio Tinto, which holds a 55% stake in the project, will contribute $79 million, while BHP holds the remaining 45% interest. The next phase of work is expected to add approximately 50 jobs.
"The Resolution copper mine has the capacity to supply 25% of US copper demand, strengthen the domestic supply chain, and deliver significant economic benefits to Arizona," said Katie Jackson, CEO of Rio Tinto.
The investment signals Rio Tinto's increased focus on copper amid rising demand driven by power grids, electrification, and AI infrastructure. It also marks another step by the US toward expanding domestic supply to secure critical minerals supply chains.
Legal Challenges
The decision follows a lengthy legal dispute over the land required for the mine, which was only recently transferred by the federal government. The controversy centered on opposition from the San Carlos Apache tribe, who argued that development could affect Oak Flat, a sacred site for the Apache people.
Although Rio Tinto has gained control of the area, the dispute highlights the challenges of balancing mineral development with Indigenous cultural and religious preservation.
Located near Superior, Arizona, the copper deposit lies 5,000 to 7,000 feet (1,524-2,134 m) underground. Rio Tinto aims to begin production in the mid-2030s, though further studies and approvals are still required.
The project has an estimated metal content of 40 billion lb (18.1 million mt) of copper, sufficient to support decades of development.
Development Outlook
The latest commitment builds on a $110 million contract awarded in August by Resolution Copper for exploration and underground development work.
As demand rises, Rio Tinto, the world's largest iron ore producer, continues to expand its copper business. Strong growth in copper revenue boosted Rio Tinto's half-year profit, underscoring the metal's importance to the company's long-term growth strategy.
The joint venture expects that once Resolution begins production, it will create thousands of jobs and generate approximately $1 billion in annual revenue for Arizona.
The mine's scale, technical complexity, and prolonged legal disputes remain significant obstacles. Developing a deposit at such depth still requires substantial infrastructure and investment before production can officially begin.
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