#1ANTOFAGASTA PLC Developing Critical Minerals for a better future BMO Global Metals, Mining & Critical Minerals Conference Iván Arriagada | Chief Executive Officer 27 February 2023 3 & PRAMONI#2Cautionary statement ANTOFAGASTA PLC 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 statements. Examples of forward- looking statements include those regarding the Group's strategy, plans, objectives or future operating or financial performance; reserve and resource estimates; commodity demand and trends in commodity prices; growth opportunities; and any assumptions underlying or relating to any of the foregoing. Words such as "intend", "aim", "project", "anticipate", "estimate", "plan", "believe", "expect", "may", "should", "will", "continue" and similar expressions identify forward-looking statements. Forward-looking statements involve known and unknown risks, uncertainties, assumptions and other factors that are beyond the Group's control. Given these risks, uncertainties and assumptions, actual results could differ materially from any future results expressed or implied by these forward-looking statements, which apply only as of the date of this presentation. Important factors that could cause actual results to differ from those in the forward-looking statements include: global economic conditions; demand, supply and prices for copper; long-term commodity price assumptions, as they materially affect the timing and feasibility of future projects and developments; trends in the copper mining industry and conditions of the international copper markets; the effect of currency exchange rates on commodity prices and operating costs; the availability and costs associated with mining inputs and labour; operating or technical difficulties in connection with mining or development activities; employee relations; litigation; and actions and activities of governmental authorities, including changes in laws, regulations or taxation. Except as required by applicable law, rule or regulation, the Group does not undertake any obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. Certain statistical and other information about Antofagasta plc included in this presentation is sourced from publicly available third party sources. Such information presents the views of those third parties and may not necessarily correspond to the views held by Antofagasta plc. This presentation is for information purposes only and does not constitute an offer to sell or the solicitation of an offer to buy shares in Antofagasta plc or any other securities in any jurisdiction. Further it does not constitute a recommendation by Antofagasta plc or any other person to buy or sell shares in Antofagasta plc or any other securities. Past performance cannot be relied on as a guide to future performance. 2#32022 Highlights Record safety performance J xxxx 0 Fatalities -35% High Potential Incidents 100% renewable energy Social value creation investment $57m Dividends 59.7cps Net cash costs $1.61/lb Copper production 646.2kt Record tonnage transported 7.1Mt Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference ANTOFAGASTA PLC $2.9bn EBITDA 50% EBITDA margin Net increase in mineral resources 920Mt Los Pelambres Expansion project 93% complete 20.6% Female participation 3#41 Safety and health Record year for safety 217 1.01 2019 Fatalities 86 0.86 2020 65 1.34 1 Lost Time Injury Frequency Rate (LTIFR) LTIFR: the number of lost time injuries per 1 million hours worked 1 2021 1 Mining division LTIFR improved 32% to 0.76 42 0.84 2022 High Potential Incidents (HPI) Our job safety analysis and critical control management are integrated into our operational model Zero fatalities since July 2021 Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference ANTOFAGASTA PLC High Potential Incidents decreased by 35%#52022 operational and financial performance Guidance achieved: 646,200 tonnes at $1.61/lb Los Pelambres Cu production 275 kt Net cash costs $1.10/lb Costs in the 1st cost quartile Production impacted by drought Centinela ● ● Cu production 248 kt Net cash costs $1.75/lb Centinela Concentrates in the 2nd cost quartile Operating above design capacity Antucoya ● ● ● Cu production 79 kt Cash costs $2.50/lb Record throughput Record production in Q4 2022 Tight cost control, productivity improvements continued ● Zaldívar ● Cu production 45 kt Cash costs $2.39/lb Chloride Leach project commissioned Focusing on optimising mine and plant operations Transport Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference ● ● Cost and Competitiveness Programme reduced costs by 7c/lb ANTOFAGASTA PLC Tonnage transported 7.1Mt Increased haulage capacity and efficiency Record tonnage transported 5#6Current political and fiscal situation in Chile New Constitution ● ● Proposed new mining royalty • Includes ad valorum and increased operating profit royalties ● • In January 2023 Bill approved by the Senate Mining and Energy ● Committee and passed to the Senate Treasury Committee for discussion ● Will then be debated in the Senate before being passed to the lower house for its consideration Proposed new Constitution rejected in a national referendum in September 2022 Congress adopted a new plan for drafting the Constitution with a new elected Council and Committee of Experts New Constitution will be put to a national referendum in December 2023 ANTOFAGASTA PLC Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference 1685 FLAM ART B 00.00 6#7Sustainability Setting ourselves high standards Safety and Health Zero fatal accidents since July 2021 35% reduction High Potential Incidents Communities Measuring the impact of our investments on our communities $57m social value creation investment 1 2 ● ● ● Ⓡ THE COPPER RESPONSIBLY MARK PRODUCED COPPER People Wellbeing Strategy rolled out 20.6% of our employees are women¹ Climate Change ICMM International Council on Mining & Metals Scope 2 100% renewable energy² Scope 1 Decarbonising operations. Scope 3 Assessing our position and working with our suppliers Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference ● ANTOFAGASTA PLC Suppliers Suppliers for a Better Future programme launched Set targets for suppliers' ESG performance Environment Biodiversity Standard updated Decreasing continental water consumption Mining division Mining division, since April 2022 Copper Mark and ICMM performance expectations - external independent certification Enhancing transparency ESG Databook available on website 7#81 2 3 Environment and climate change Committed to emissions reduction and efficient water use Mining division Since 2020 2022 GHG emission targets 30% Reduction by 2025 Carbon neutral by 2050 100% renewable energy since April 2022¹ 1 million tCO₂e reduction² in Scope 2 emissions 84%³ of water used is recirculated ANTOFAGASTA PLC 45%³ of water used is from the sea Sea and recirculated water More than 90% of total operational use by 2025 Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference 8#9Puerto Mejillones Antofagasta Puerto Huasco Antucoya 1 Growth portfolio update Developing our projects Cachorro Cachorro Vallenar End 2022 Centinela Encierro Encierro ● ● Inferred resources 242Mt @1.21% Cu. 70% increase since 2021 Drilling continues in 2023 Maiden inferred resource 522Mt @0.65% CuEq EXPLORATION FOCUSED ON CHILE, PERU, USA AND CANADA Only 15% of property has been drilled Exploration 2030+ ● Los Pelambres Expansion Phase 2 Increases throughput to 205,000 tpd and extends life of mine by 15+ years Requires two separate EIA applications ● ● Centinela Second Concentrator Stack FID decision during 2023 Capital cost $3.7 billion Moves Centinela to 1st cost quartile Development 2025+ ● ● Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference Los Pelambres Expansion Phase 1 CCCLCI FJOR JEFFRE 93.4% complete¹ 400 l/s desalination plant and concentrator expansion to 190,000 tpd Construction 2023 Esperanza Sur pit Cu +10-15,000 tpa Capex $170m . ● ANTOFAGASTA PLC Zaldivar Chloride Leach Cu +10-15,000 tpa Capex $190m ● Completed 2022#10Recent exploration success Group mineral resources increased by 920Mt Puerto Mejillones Antofagasta Puerto Huasco Antucoya uasco Teirina Cachorro 242Mt @1.21% Cu Vallenar 522Mt @0.65%Cu, 0.22g/t Au, 74ppm Mo Centinela Alte Del Carmen Encierro Cachorro ● • Latest Group discovery generated by our greenfield exploration programme Potential to become one of the most important manto-type deposits in the coastal metallogenic belt of northern Chile ● ● Estimated inferred resource for the central part of the deposit, represents only a part of its potential Lies between Antucoya and Centinela • Infill drilling will continue during 2023 ● ANTOFAGASTA PLC Encierro Encierro deposits is a complex Cu-Au-Mo porphyry system is one of the most important discoveries within the El Indio and Maricunga belts. Maiden inferred resources of 522Mt @ 0.79CuEq in 2022 Remains open. Further exploration is 2023 Antofagasta (57%) is forming a mining contractual company with Barrick (43%). ● ● Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference 10#11Los Pelambres Expansion Phase 1 Concentrator Plant EMENANNS VTZ A Piperdek, flotation plant SAG milk 1 STATCOM: Static synchronous compensator 2 GIS: Gas Insulated Switchgear 201 imm STATCOM¹ y GIS2 EMIN 1X1 Desalination Plant Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference 7459 Reverse osmosis plant Pre-treatment area ANTOFAGASTA PLC Pumping system 11#12Reliable and responsible copper producer Potential 900,000 tpa of copper 1 Organic growth key strength of our portfolio Solid bases four mines in two world-class districts in Chile Management risks Technical, social, environmental and commercial risks have been assessed End 2022 Indicative directional projection including projects not yet approved and subject to risk uncertainty Actual 2023 - 2025 +12-14% vs Actual 100%¹ complete Esperanza Zaldivar Sur Pit Chloride leach 93% ¹ complete Los Pelambres expansion phase 1 Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference ANTOFAGASTA PLC 2026 2027 +32-35% vs Actual Centinela 2nd concentrator ~900 12#13Cost and Competitiveness Control Technology and cost discipline 23 Results CCP¹ 2022 $ million 50 Target 1 148% 1 Cost and Competitiveness Programme Includes 100% of Zaldívar Integrated Remote Operations Centre 124² 88 Savings (5c/lb) 36 Actual Productivity (2c/lb) Cash costs before by-product credits -7c/lb vs Actual 2021 Cost control Contract management Consumption of operational inputs Organisational productivity Technology Autonomous operation in Esperanza Sur Pit was completed Centinela's and Los Pelambres' IROCS³ went fully operational during 2022 Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference ● ● ANTOFAGASTA PLC Full capacity Centinela and Antucoya operating above design capacity Use of equipment (Drilling and blasting platform) Innovation Cuprochlor®-T patent was granted in Chile in 2022 after successful completion of the industrial-scale trial at Centinela 13#1412345 2023 Guidance Responsible and reliable copper producer Group production 646 kt 2022 Guidance 670-710 kt 2023E Production Growth Increasing quarter-by-quarter. First production from Los Pelambres Expansion in Q2 2023 Net cash costs $1.61/lb Assumed CLP/USD exchange rate of 850 Includes by-product credits at a gold price of $1,750/oz and a molybdenum price of $18.0/lb Cash flow. Excludes Zaldívar. Attributable Zaldívar capital expenditure was $55m in 2022 Cost and Competitiveness Programme Tailings Storage Facility Net cash costs FY 2022 0.01 FX 0.03 Guidance $1.65/lb By-product Net cash costs production 2023E and price Cost Control Higher production, CCP 4 savings and decreased input costs, offset by inflation Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference Capital expenditure³ $1,880m 59 676 583 562 2022 Guidance $1.9bn 2023E b ANTOFAGASTA PLC Transport & corporate Growth Mine development Sustaining (mining) Capital Allocation Includes major infrequent sustaining projects (desalination expansion, concentrate pipeline and TSF 5 expansion), increased mine development and inflation 14#15Capital allocation framework Creating sustainable value & shareholder returns over the long term Operating Cash Flow Sustaining Capex & Mine Development Committed Dividends (35% pay-out) Strong Balance Sheet Growth Capex Excess Cash Dividend $588 million total dividend 100% of underlying net earnings Macro Perspective Decision Factors Financial Position Value Optimisation Climate Resilience Dividend, capex & pay-out ratio $ million, % 65% 873 332 2018 35% 1,079 Antofagasta plc | 2023 BMO Global Metals, Mining & Critical Minerals Conference 176 2019 100% 1,307 539 2020 Total dividends Capex 100% 1,778 1,405 2021 ANTOFAGASTA PLC Pay-out ratio 100% 1,879 80% average pay-out ratio Last 5 years 588 2022 15#16CENTINELA Developing mining for a better future Sustainable returns to shareholders and delivering value to all stakeholders • Committed to keeping our people and communities safe and healthy while creating further social value Embedding climate change and sustainability strategy across all decision making and update climate change targets • Maintaining operating resilience and flexibility • Continuous productivity improvements to optimise margins Advancing our growth projects and innovation portfolio#17ANTOFAGASTA PLC Developing Critical Minerals for a better future BMO Global Metals, Mining & Critical Minerals Conference Iván Arriagada | Chief Executive Officer 27 February 2023 3 & PRAMONI