Rio Tinto has approved $144m in funding to advance the next development phase of the Resolution Copper project located near Superior Arizona, US, with the company’s share totalling $79m.
The investment is intended to progress work at the site, which is managed by Resolution Copper Mining, a joint venture (JV) held 55% by Rio Tinto and 45% by BHP.
It will support feasibility studies and final design engineering for material handling systems in the project’s two shafts and for new water treatment facilities.
The funding will also provide for ongoing exploration drilling, procurement of underground development and production equipment, as well as long-lead electrical equipment.
Around 50 new positions are expected to be created in areas such as mining, geology, engineering, and project services as part of the development programme.
This latest investment builds upon the completion of a land exchange in March 2026, which enabled Resolution Copper to progress to its next phase.
At that time, Rio Tinto announced around $500m in preliminary spending for the project.
Resolution Copper is expected to supply a significant new source of domestically produced copper for the US and could contribute about $1bn each year to Arizona’s economy, while generating thousands of direct and indirect jobs.
The copper deposit is situated between 5,000 and 7,000ft beneath the surface.
Rio Tinto copper chief executive Katie Jackson said: “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.
“Following completion of the historic land exchange in March, this investment is another important step in advancing the project.
“These funds will accelerate underground development, create additional skilled roles and ensure Resolution Copper is well positioned for its next investment decision, while maintaining safe underground operations and construction.”
Last month, Rio Tinto opened two lithium operations in the Argentine province of Catamarca after a joint investment of nearly A$1.4bn ($985m).
