Slide 1: Focused on Copper: Site Visit Presentation
Focused on Copper Site Visit Presentation Centinela Second Concentrator 5-6 November 2025
Slide 2: Agenda
Agenda 1 | Overview 2 | Project management 3 | Delivering growth and value 2 Antofagasta plc | 2025 Site Visit Presentation (Day 2, Centinela)
Slide 3: Overview: Centinela Second Concentrator Project
1 Overview Centinela Second Concentrator Project Carlos Ruiz Project Manager 3 Antofagasta plc | 2025 Site Visit Presentation (Day 2, Centinela)
Slide 4: Delivering growth and value
Key attributes Delivering growth and value Economic value Geoscience Technology Environment and Sustainability permits • +170 ktpa CuEq production1, • Project builds on +20 years of • Further expansion of fleet • 100% of critical permits • 100% renewable energy and fully integrated with existing ope
Slide 5: Mine, processing and infrastructure
Scope Mine, processing and infrastructure ESPERANZA SUR ENCUENTRO 8 1 Esperanza Sur Pit Development 1 2 2 Esperanza Sur Primary Crusher 3 5 3 3 New Concentrator Plant (95 ktpd) 3.1 SECONDARY CRUSHER 3.2 TERTIARY CRUSHER HPGR 4 New thickened tailings storage facility 3.3 GRINDING AND FLOTATION 4 6 3.
Slide 6: Centinela Second Concentrator Video
Video Centinela Second Concentrator 6 Antofagasta plc | 2025 Site Visit Presentation (Day 2, Centinela)
Slide 7: Project highlights: Progress in numbers
Project highlights Progress in numbers Safety Employment Progress Capex Installed commodities Zero >12,000 >50% >50% 6.7M m3 Fatalities project to date Hired workers Construction progress, according Project expenditures executed to schedule Earthworks to date 0.47 +27% 100% 170,000m3 Project Lost ti
Slide 8: Major expansion: Key milestones
Project progress Major expansion: Key milestones 2027 - 2023 2024 2025 2026 2028 - 2029 • Approval of investment • Start of construction • Start of Esperanza Sur • Start of pre commissioning • Late 2027: Start of ramp up mine development • Conclusion of project • Start of water and energy • Late 202
Slide 9: Project management
2 Project management Centinela Second Concentrator Project 9 Antofagasta plc | 2025 Site Visit Presentation (Day 2, Centinela)
Slide 10: Execution structure: Effective allocation of risks
Execution structure: Vertical packages Effective allocation of risks Centinela Second Concentrator Project Areas managed by Centinela operation Antofagasta Team (Owner) Integration Mine Operational development business Programme Management and readiness (Integrator, Administrator, Systems, QA/QC) eq
Slide 11: Project update: In line with original commitment
Project update In line with original commitment Expenditures remain on track and according Capex composition project to date to original plan VP0 Services, owner 10% team, others VP1 20% 6% VP5 6% VP4 4% VP3 2024 2025 2026 2027 7% Actual Estimated Estimated Estimated VP2 47% 11 Antofagasta plc | 202
Slide 12: Experienced team
Experienced team Bringing experience from different projects 45 12 20+ 5 Patricia Downing Carlos Ruiz Project Vice-president Project Manager 30+ 7 25+ 4 25+ 5 Gonzalo Irribarra Alejandro Burotto Mauricio Acosta VP2 Manager Deputy Project Manager Project Manager Concentrator Santiago 25+ 7+ 25+ 5 25+
Slide 13: Material handling: Managing ore supply from 2x sulphide pits
Vertical package 1: Material handling Managing ore supply from 2x sulphide pits 2 5 1 3 4 Scope 1 MSE Wall 4 Overland conveyor 2 Primary Crusher 5 Stacker 3 Sacrificial conveyor belt 6 23 kV mine loop extension 13 X Not shown in the 3D view Antofagasta plc | 2025 Site Visit Presentation (Day 2, Cent
Slide 14: Material handling: Progress as of October 2025
Vertical package 1: Material handling Progress as of October 2025 2 5 1 4 3 Scope 1 MSE Wall 4 Overland conveyor 2 Primary Crusher 5 Stacker 3 Sacrificial conveyor belt 6 23 kV mine loop extension 14 Antofagasta plc | 2025 Site Visit Presentation (Day 2, Centinela)
Slide 15: Concentrator plant: 1st quartile facility
Vertical package 2: Concentrator plant 1st quartile facility with modern technologies Scope 9 1 Coarse ore stockpile 2 Secondary crusher x 3 (MP1250) 3 Tertiary crusher x 3 (HPGR) 4 Belt conveyors 7 3 5 Ball mill x 2 6 Flotation 6 7 Regrinding-Concentrate thickener Concentrate pipeline / 5 11 8 Moly
Slide 16: Concentrator plant: Progress as of October 2025
Vertical package 2: Concentrator plant Progress as of October 2025 Scope 9 1 Coarse ore stockpile 7 2 Secondary crusher x 3 (MP1250) 6 10 3 Tertiary crusher x 3 (HPGR) 3 4 Belt conveyors 5 11 5 Ball mill x 2 2 6 Flotation 7 Regrinding-Concentrate thickener 4 Concentrate pipeline / 8 Molybdenum plant
Slide 17: Increased thickened tailings impoundment capacity
Vertical package 3: High density tailings storage facility and water reclaim system Increased thickened tailings impoundment capacity Scope • Thickened tailings deposit (capacity 2,100 Mt) • Tailings transport and distribution • Water Management System: o Contact water → water reclaim system (pumpin
Slide 18: Starter wall progress as of October 2025
Vertical package 3: High density tailings storage facility and water reclaim system Starter wall progress as of October 2025 Scope • Thickened tailings deposit (capacity 2,100 Mt) • Tailings transport and distribution • Water Management System: o Contact water → water reclaim system (pumping) o Non
Slide 19: Concentrate and port infrastructure expansion
Vertical package 4: Water supply infrastructure, port and concentrate transport system Concentrate and port infrastructure expansion Concentrate stockpile expansion Filter building Scope expansion • New Sea Water Pipeline • Upgrade of Power transmission line 220/110KV • Pumpstations EB1, EB2 and EBC
Slide 20: Water supply, port and concentrate: Progress as of October 2025
Vertical package 4: Water supply infrastructure, port and concentrate transport system Progress as of October 2025 Scope • New Sea Water Pipeline • Upgrade of Power transmission line 220/110KV • Pumpstations EB1, EB2 and EBCA • Thickening, filtering and stock of copper concentrate capacity increase
Slide 21: Facilities supporting Centinela's growth
Vertical package 5: Infrastructure Facilities supporting Centinela’s growth Scope • Construction Camp Civic area, Waste Management System (Centinela Cathodes), • Explosive magazine, Fuel station, water station, Laboratory sampler • Internal road construction y maintenance and water infrastructure fo
Slide 22: Key takeaways
Centinela Second Concentrator Project Key takeaways Safe execution 18 months of project construction, 26 million hours completed with no major injuries. >50% executed, on time and on budget Schedule risk analysis provides support to meeting execution timeline. Major equipment and materials delivered
Slide 23: Delivering growth and value
3 Delivering growth and value Centinela Second Concentrator Project 23 Antofagasta plc | 2025 Site Visit Presentation (Day 2, Centinela)
Slide 24: Connecting Centinela to our investment case
In summary Connecting Centinela to our investment case Copper: Significantly increasing Centinela’s 1. contribution to Group production 1 Margins: Centinela Concentrates is a 1st quartile 2. operation, with a significant gold stream 2 3 4 Growth: Expansion underway today, and further 3. potential th
Slide 25: Cautionary statement
Appendix Cautionary statement This presentation has been prepared by Antofagasta plc. By reviewing and/or attending this presentation you agree to the following conditions: This presentation contains forward-looking statements. All statements other than historical facts are forward-looking statement