$2.07B Copper World mine approved for construction in southern Arizona

Construction has been approved for the $2.07 billion Copper World project in southern Arizona, advancing a major new open-pit copper mine and processing complex towards first production in the second half of 2029. Hudbay Minerals and Mitsubishi Corporation, which hold the project through a 70/30 joint venture, took the final investment decision on 21 October following completion of a definitive feasibility study.

Located around 50 km southeast of Tucson, the project will be developed as a large truck-and-shovel mining operation covering four primary pit areas: East, Broadtop, West and Peach-Elgin. The initial development programme is expected to take around 36 months and will include the mine pits, waste-rock facilities, ore stockpiles, a tailings storage facility and a 60,000 ton-per-day concentrator.

The permitted base development has a planned operating life of approximately 15 years and remains entirely on private land, requiring only state and local approvals, which have already been secured. Proven and probable reserves are estimated at 390 million tonnes grading 0.47% copper, with average annual production expected to reach around 102,000 tonnes of copper during the first decade of operation at average cash costs of $1.65 per pound.

The processing facilities form a major part of the initial construction programme, but the project has also been designed around several potential later expansions. Approximately $710 million of additional capital could be invested after startup, including a $25 million molybdenum plant in the first year of operation, a $242 million in-pit crushing and conveying system in year three and a $443 million concentrator expansion in year four.

That final expansion would increase processing capacity from 60,000 to 90,000 tons per day from year five. To support the higher throughput without requiring an additional water supply, the development plan includes converting around one-third of the mine's tailings to filtered tailings beginning in approximately the fifth year of operation.

Filtered tailings remove a greater proportion of water from the processed material before deposition, allowing more water to be recovered and reused within the operation. Their planned introduction is therefore closely linked to the project's future processing expansion and water-management strategy in the arid Arizona environment. Water remains the central local objection to the scheme: Pima County and the City of Tucson have both formally opposed it, citing an aquifer already experiencing declining levels and subsidence, while Hudbay's water-pumping permit expires in January 2028. The Tohono O'odham Nation has also objected on the grounds that the Santa Rita Mountains hold sacred sites.

The in-pit crushing and conveying system is another significant future component. Designed to handle up to 100,000 tons per day, it would crush ore in the East pit and move it by conveyor to stockpiles and the processing plant, reducing haul-truck requirements, emissions and operating costs as the pits deepen.

The approved base project could later be expanded beyond the private-land footprint. A longer-term development scenario would incorporate adjacent federal land from around the tenth operating year, subject to additional federal approvals, and could extend the overall mine life to approximately 37 years.

Early site works have already been progressing, with the full construction decision now moving the project into its main development phase. More than 1,000 construction jobs are expected during delivery, followed by around 500 permanent operational positions once the mine enters production. Construction capital will come largely from Mitsubishi's initial $600 million equity investment, a $230 million precious-metals stream deposit from Wheaton Precious Metals, around $127 million in equipment financing and approximately $650 million in project-level debt, with Hudbay's first capital contribution deferred to 2028.

The scale of Copper World lies not only in the mine itself but in the integrated infrastructure required to support it. Open-pit excavation, processing, tailings management, water recovery, material conveying and future plant expansion have all been incorporated into a development programme intended to support more than 100,000 tonnes of annual copper production during its first decade.