Mr. Cashel Meagher reports

CAPSTONE COPPER RECEIVES MANTOVERDE OPTIMIZED PERMIT

Capstone Copper Corp. has received the DIA environmental permit (declaracion de impacto ambiental) for the Mantoverde Optimized project from the Atacama Regional Environmental Assessment Commission.

Mantoverde Optimized is a capital-efficient brownfield expansion of Mantoverde's sulphide concentrator, increasing throughput from 32,000 to 45,000 ore tonnes per day and extending the mine life from 19 to 25 years. The issuance of this permit represents a significant milestone for the advancement of the project, as it is the only major permit required for the development and operation of MV-O.

Cashel Meagher, Capstone's president and chief executive officer, commented: "MV Optimized is a capital-efficient, high-return and low-risk expansion project that is expected to bring on an additional 20,000 tonnes per annum of copper production for approximately $150-million of expansionary capital. We have been eagerly awaiting this permit and are excited to begin construction, pending required board approvals, to increase our throughput capacity by over 40 PER CENT at very low capital intensity."

Mr. Meagher added: "MV Optimized, when combined with our Santo Domingo project next door, defines the next phase of transformational growth for Capstone. We envision the Mantoverde-Santo Domingo district becoming one of the largest producing copper districts in the world with very attractive unit cash costs, well positioned to meet the growing requirements for copper globally. Our team is committed to pursuing the highest standards in safety and environmental management as well as ensuring continued engagement with all stakeholders as we progress our growth plans."

Advancing the path toward transformational growth

The DIA environmental permit application was submitted in the first half of 2024, in advance of the MV-O feasibility study announcement in October, 2024. Capstone received the DIA permit on schedule and the company is pleased with the level of engagement evidenced throughout the process.

During Q2 2025, approximately $20-million in orders for long-lead items for MV-O were approved. The company plans to provide further updates with respect to 2025 expansionary capital expenditures guidance and project timing upon formal project sanctioning, subject to board approvals.

Mantoverde operation summary

Mantoverde (70 per cent owned by Capstone Copper and 30 per cent owned by Mitsubishi Materials Corp.) is an open-pit copper-gold mine located in the Atacama region of Chile. Since the 1990s, Mantoverde operated as an oxide mine producing copper cathodes from its 60,000-tonne-per-annum capacity SX/EW (solvent extraction/electrowinning) plant. In 2023, Capstone Copper completed construction of the Mantoverde development project (MVDP) that enabled the mine to process its copper sulphide reserves, in addition to existing oxide reserves. The MVDP involved the addition of a sulphide concentrator and tailings storage facility and the expansion of the existing desalination plant and other minor infrastructure. First saleable copper concentrate at MVDP was produced in June, 2024, and commercial production was achieved in September, 2024. In January, 2025, the plant achieved an average throughput of 33,409 tonnes per day, exceeding its current nameplate capacity.

Qualified persons

Peter Amelunxen, PEng, senior vice-president, technical services, of Capstone Copper, a qualified person, as defined by National Instrument 43-101, reviewed and approved the content of this news release that is based on the 2024 technical report.

About Capstone Copper Corp.

Capstone Copper is an Americas-focused copper mining company headquartered in Vancouver, Canada. Capstone Copper owns and operates the Pinto Valley copper mine located in Arizona, United States, the Cozamin copper-silver mine located in Zacatecas, Mexico, the Mantos Blancos copper-silver mine located in the Antofagasta region, Chile, and 70 per cent of the Mantoverde copper-gold mine, located in the Atacama region, Chile. In addition, we own the fully permitted Santo Domingo copper-iron-gold project, located approximately 30 kilometres northeast of Mantoverde in the Atacama region, Chile, as well as a portfolio of exploration properties in the Americas.

Capstone Copper's strategy is to unlock transformational copper production growth while executing on cost and operational improvements through innovation, optimization and safe and responsible production throughout the company's portfolio of assets. Capstone Copper focuses on profitability and disciplined capital allocation to surface stakeholder value. Capstone Copper is committed to creating a positive impact in the lives of its people and local communities while delivering compelling returns to investors by responsibly producing copper to meet the world's growing needs.

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