Chilean copper miner Antofagasta’s Centinela operation has reached a milestone in its expansion strategy with the first blast at the new Encuentro Sulphides pit.

The initial blast forms part of early stripping activities that will prepare the site for production, with sulphide ore from Encuentro set to feed Centinela’s Second Concentrator – currently under construction – alongside ore from the existing Esperanza South pit.

The expansion is designed to optimise value extraction from Centinela’s 2.6-billion-tonne ore reserve base and supports Antofagasta’s goal of increasing total copper production by 30% over the medium term.

Approved in July 2025 with an estimated $1-billion investment, the Encuentro Sulphides project is expected to complete its stripping phase by 2028. The deposit, incorporated into Antofagasta’s year-end 2024 reserves, contains an estimated 738-million tonnes at 0.45% copper, with associated by-products of 0.17 g/t gold and 0.015% molybdenum. This compares favourably with the broader Centinela sulphide reserve grade of 0.41% copper.

Once operational, the Encuentro Sulphides pit will become the main ore source for the Second Concentrator, which will add 95 000 t/d of processing capacity. The concentrator will incorporate high-pressure grinding rolls and other modern processing technologies to improve efficiency and recovery. Over its first decade of operation, the facility is expected to contribute an average of 170 000 t/y of copper-equivalent production – comprising about 144 000 t of copper, 130 000 oz of gold, and 3 500 t of molybdenum.

The Second Concentrator project also includes a significant expansion of Centinela’s infrastructure, including upgrades to its raw seawater pumping system, new tailings storage facilities, and enhanced logistics for both energy supply and concentrate transport. These developments will strengthen operational reliability and sustainability as Centinela scales up output.

During the pre-stripping phase, about 186-million tonnes of material will be moved over two years. The project will also progressively introduce autonomous mining equipment, following the successful deployment of autonomous haul trucks at Esperanza Sur, with full autonomy targeted from January 2026.