Capstone Copper has announced that it has sanctioned the Mantoverde Optimised (MV Optimised) project in Chile for construction.
The green light follows the necessary Board approvals and receipt of the DIA environmental permit in early July.
Mantoverde, which is 70% owned by Capstone Copper and 30% by Mitsubishi Materials, is an open-pit copper-gold mine in Chile's Atacama region.
The MV Optimised project marks a significant expansion of the Mantoverde sulphide concentrator, which will see an increase in throughput from 32,000 to 45,000 tonnes per day (tpd).
The project aims to provide incremental copper and gold production of approximately 20,000 tonnes and 6,000oz per annum, respectively, while extending the mine life from 19 to 25 years.
To facilitate this growth, the current process infrastructure at Mantoverde will undergo debottlenecking to support the enhanced throughput.
Additional mining and plant equipment will be necessary to sustain the expanded mining and processing rates.
Capstone CEO Cashel Meagher said: “Sanctioning of our MV Optimised project represents a significant milestone on our continued path towards transformational growth.
“With the required Board and regulatory approvals in-hand, we will now commence construction on our capital efficient, quick payback and high return expansion project at Mantoverde.”
Since its inception in the 1990s as an oxide mine, Mantoverde has been producing copper cathodes from its SX-EW plant.
The first saleable copper concentrate was produced in June 2024, with commercial production commencing in September 2024.
By the second quarter of 2025 (Q2 2025), the plant had already surpassed its design capacity, averaging throughput of 33,409tpd.
Capstone estimates that the construction of the MV Optimised sulphide concentrator expansion will take around one year, with a ramp-up period following in Q4 2026.
The company anticipates that the increased sulphide throughput capacity of roughly 45,000tpd will be sustainable, starting in early 2027.
With detailed engineering 40% complete, Capstone has de-risked the project, providing greater certainty in timelines and capital expenditure estimates.
The total expansionary capital cost for the MV Optimised project is estimated at $176m (C$242.28m).
This budget includes additional mining equipment, upgrades to the concentrator processing plant, infrastructure improvements for heap and dump management, conversion of the dynamic heap to a bioleach facility and upgrades to the desalination plant.
With the sanctioning decision, Capstone has revised its expansionary capital guidance for 2025 upwards by $60m, totalling $70m for the Mantoverde expansion and $120m consolidated. The remaining $106m is expected to be spent in 2026.
In addition, Capstone upsized its senior notes offering to $600m in March, with the notes due in 2033 carrying an interest rate of 6.75% per annum and backed by the company's subsidiaries.
