Hudbay Minerals now expects to contribute approximately $500 million to develop its Copper World mine in Arizona, more than double the $200 million it estimated when announcing Mitsubishi Corporation’s investment in August 2025.
The revised funding requirement emerged Wednesday as the partners authorized construction of the $2.07 billion copper project.
The earlier figure relied on a 2023 pre-feasibility study, while the new estimate reflects the definitive feasibility study and a revised financing structure.
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Hudbay owns 70% of Copper World, with Mitsubishi holding 30%. Despite that ownership split, Hudbay expects to cover less than a quarter of initial project capital through direct contributions, with its first payment deferred until 2028.
The financing plan uses Mitsubishi’s previously announced $600 million investment, a $230 million precious metals streaming deposit from Wheaton Precious Metals, and approximately $650 million in anticipated project-level debt. Mitsubishi has separately authorized up to $423 million in additional equity, although Hudbay says that would decline to approximately $218 million if the planned debt financing is obtained.
The revised feasibility study also shows how Copper World’s development plan has changed. Its $2.07 billion initial capital estimate, calculated net of $127 million in anticipated equipment financing, includes about $200 million attributable to scope changes since the 2023 study.
Following approval, Hudbay raised projected 2026 growth spending tied to the joint venture to $245 million from the previously outlined $135 million, reflecting an additional $110 million of construction and development spending during the fourth quarter.
First production is targeted for the second half of 2029. Hudbay projects average annual copper output of 102,000 tonnes over the first decade, up from 92,000 tonnes in the 2023 study, with average cash costs of $1.65 per pound.
The base-case operating plan covers 15 years, rather than the 20 years outlined previously, as the updated design processes ore faster. An alternative 37-year scenario would require federal permits to expand operations onto additional land.
At an assumed copper price of $5 per pound, the company estimates a $1.24 billion after-tax net present value at an 8% discount rate and a 16.8% project internal rate of return for the base case.
Hudbay also disclosed plans to increase its revolving credit facility to $700 million from $450 million and extend its maturity to November 2030, subject to expected fourth-quarter closing.
