Resolution Copper Mining, a joint venture between Australia-headquartered miners Rio Tinto and BHP, has approved a $144-million investment in the next phase of development at the Resolution Copper project, in Arizona, in the US – one of the world’s largest untapped copper deposits and a potential major new source of domestically produced copper for the US.

The investment builds on the completion of the historic land exchange in March, which unlocked the project’s next phase. It is additional to about $500-million of preliminary spending announced at that time.

The latest investment will fund feasibility studies and final design engineering for the installation of development and production-level materials handling equipment in both shafts and new water treatment facilities. It will also support ongoing exploration drilling, the purchase of underground development and production equipment as well as long-lead electrical equipment.

Rio Tinto explains that 50 additional roles will be created across mining, geotechnical and geological disciplines, engineering and project services.

“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,” says Rio Tinto Copper CE Katie Jackson.

Rio Tinto says Resolution Copper has the potential to become one of the largest copper mines in the US, create thousands of direct and indirect jobs and contribute about $1-billion a year to Arizona’s economy.

"This investment builds on the momentum created by the historic land exchange and marks another important step towards unlocking Resolution Copper's potential. 

"We are moving forward with urgency and discipline. This programme will accelerate underground development and our path towards first copper production while maintaining safe underground operations and construction, positioning the project strongly for its next investment decision," comments Resolution Copper Mining president Vicky Peacey.

Rio Tinto, which holds a 55% interest in Resolution Copper Mining, will contribute about $79-million of the $144-million investment.