Tucumã Operation

Open-pit copper mine in southeastern Pará State held through MCSA (99.6% Ero interest), formerly the Boa Esperança Project. Commercial production was declared effective July 1, 2025, with copper production increasing sequentially each quarter of 2025 during ramp-up; post-commercial H2 2025 production was 16,780 tonnes at C1 cash costs of $1.69/lb. Q4 2025 was the strongest quarter to date (9,275 t) despite extended December downtime for early mill liner replacement. Closure activities are projected over 2036-2041. Technical basis: NI 43-101 'Boa Esperança Project Technical Report on Feasibility Study Update' (Ausenco/NCL/HCM, effective August 31, 2021).