Antofagasta : Financial Reporting Document

Contents

Chapter 1

WE ARE ANTOFAGASTA MINERALS

Chapter 3

CORPORATE GOVERNANCE

Chapter 6

APPENDIX

OUR REPORTING SUITE

GRI 2-3

This is Antofagasta Minerals' seventeenth Sustainability Report and covers our strategy, priorities and performance regarding the main material sustainability issues for our business and our stakeholders between January 1st and December 31st, 2023. It encompasses the following operations: Los Pelambres, Centinela, Antucoya, Zaldívar and Antofagasta Minerals' corporate headquarters. This report was prepared in accordance with the Global Reporting Initiative Standards (GRI) 2021.

Our main 2023 sustainability figures and 2018-2023 data are available in our Sustainability Databook, where we publish Antofagasta plc performance, along with the results of each of our four mining companies and information concerning the transport division. The GRI index can be found in this document.

In this Sustainability Report, the terms "Company", "Group", "we", "us", "our" and "ourselves" are used to refer to Antofagasta Minerals and, unless the context requires otherwise, its subsidiaries. These terms may be used as collective expressions where general reference is made to the companies in the

Delivering performance and growth

Annual Report and Financial Statements 2023

Annual Report 2023antofagasta.co.uk/investors/annual-report-2023/

Sustainability Databook

antofagasta.co.uk/sdb

Tax Progress Report

antofagasta.co.uk/tax22

Climate Change Report

antofagasta.co.uk/ccr22

Social Value Report

antofagasta.co.uk/svr22

Climate Action Plan

antofagasta.co.uk/CAP

Group and/or where no useful purpose is served by identifying any particular company or companies.

Point of contact for questions about the report or reported information: inforeporte@aminerals.cl

The Databook and this report were verified by EY. Both documents are first presented to and reviewed by the Sustainability and Stakeholder Engagement Committee who gives its opinion to the Board of Directors. The report and Databook are then presented to and approved by Board.

All $ in this report refer to US dollars unless otherwise indicated.

March 2024.

Our purpose

Developing mining for a better future

For whom we want to achieve our purpose

Planet

We recognise that climate change is one of the greatest challenges faced by humanity. Our vision of a better future reflects the quest for a more sustainable planet, with copper playing a central role in the energy transition, economic progress and improved livelihoods.

Society

Our vision of a better future is one that is developed together with our local communities, and aims for a society that recognises the economic and social value generated by mining.

Organisation

To tackle the challenges we face in our daily operations and growth, we need a robust organisation that consistently meets these challenges and is grounded in clear and unshakeable values and principles.

Our vision of a better future therefore encompasses our ethical organisational behaviour and our continuous pursuit of a sustainable culture of trust, inclusivity, collaboration, agility and willingness, to embrace change and continuous learning.

People

Our success relies on having the best people at the heart of everything we do. Our vision of

a better future would be incomplete without the shared values of our workforce, a diverse and inclusive group of individuals open to learning and to enjoying their personal and professional growth, who strive for excellence in their results.

How we will achieve our purpose

Safety and Sustainability

People and culture

Competitiveness

Innovation

Growth

Underpinned by our values

Respect for others

Responsibility for safety and health Commitment to sustainability Excellence in our performance

Innovation as a permanent practice

Forward thinking

Respect for others

We respect people and care about their opinions, which is why we engage in an open, transparent and collaborative way. We trust them and have a genuine interest in their well-being. We promote a work environment that fosters diversity and inclusion.

At Antofagasta, we seek to achieve and enhance a positive long-term impact on society based on our values, corporate policies and standards, and by reviewing risks and opportunities that could have an impact on our business. The Board is responsible for analysing, leading and monitoring sustainability policies and best practices.

Safe and healthy environment

A safe and healthy environment is a priority for our work, as is well-being. We recognise the importance of diversity and equal opportunities, so we continually strive to create proper environments that promote integration and both professional and personal development.

We strive for continuous improvement, regularly evaluating our environmental performance to tackle the most critical challenges associated with the management of water resources, air quality, biodiversity, waste, heritage culture, land use, climate change and energy.

Social development

We seek to contribute to the generation of economic, social and human capital in our areas of influence in which we operate. We lead processes of effective, participatory and transparent dialogue, with the different actors in the territory, acknowledging challenges and opportunities to address them together.

Pe o p l e

Economic performance

We are constantly looking for sustainable ways to improve our operational efficiency, in order to create value for our stakeholders. We operate responsibly and with long-term vision, to maximise the economic value of our assets and contribute to social development.

Environmental management

We work to prevent, control and mitigate our potential environmental impacts. We seek always

Transparency and corporate governance

We believe in the importance of developing effective, responsible and transparent institutions. Our guidelines and internal regulations establish our commitment to run a responsible business. We operate with integrity based on transparency and respect for human rights and the law.

We openly communicate our performance and implement systems that allow us to supervise our procedures internally.

to make efficient use of natural resources. We implement integrated environmental management systems into our business, establishing objectives, goals and indicators.

Additionally, we have systems for the control and management of the minerals used in the manufacturing of the products we deliver to our clients, in accordance with the OECD due diligence standards on the origin of minerals and responsible sourcing principles.

Please see page 33-34 of our Annual Report for more information on our other policies and models.

IVÁN ARRIAGADA

Chief Executive Officer

Dear stakeholders,

At Antofagasta Minerals, copper is the core of our business and sustainability lies at the heart of our strategy. In line with our purpose of developing mining for a better future, in this Sustainability Report we have shared our main achievements across 2023 as a Mining Group in the economic, environmental, social and governance spheres.

We foster our long-term value creation through five robust strategic pillars: safety and sustainability, competitiveness, people and culture, growth, and innovation, all of which are supported by tailor-made policies and practices that are embedded throughout our organisation and are underpinned by our corporate values. We rigorously apply the best local and international standards regarding our people, including our suppliers and local communities, wherever we engage them.

We take care of our people

We had zero fatalities in 2023 as in 2022. Our LTIFR1 has consistently decreased over the last two years. In 2023, we advanced in the consolidation of our management system by embedding occupational health and safety planning into our operational model, with the aim of ensuring the implementation of critical controls to prevent unplanned events.

At Antofagasta Minerals, we believe in the value of diversity and strive to increase the number of women employed in our mining activities. We are proud to have surpassed our internal 2023 goal of 22%, with women now accounting for 23.7% of the talent involved in our activities.

Sustainable growth

We are aware of the key role of copper in the energy transition

and increasing associated demand for the metal worldwide. We have therefore been working to achieve greater levels of efficiency in our operations and projects. We are especially proud of the sustainable approach involved in our recently approved Centinela Second Concentrator project.

This investment is a key decision for achieving our long-term growth plans. Construction will begin during the first half of 2024 and the plant will enter operation in 2027. At its peak, it will create around 13,000 jobs, with local employment being our priority. In line with our innovation and sustainability practices, it will continue to use 100% seawater across the production process, along with renewable energy. The project involves a second milling plant, a new thickened tailings deposit, and it will operate with autonomous trucks and drilling rigs. It will be managed remotely bringing greater safety and quality of life to our people.

Water is also a key element in our Climate Change Strategy, which

is framed in our Sustainability Policy. In 2023, the Coquimbo Region's Environmental Evaluation Commission gave approval to Los Pelambres Operational Adaptation project, which will double the capacity of the desalination plant to 800 litres/second. When the plant is ready, our goal is that 90% of the water that is used for the operations will be seawater or recirculated water.

1. LTIFR - Number of accidents with lost time on the part of own workers and contractors per million hours worked.

Our approach to climate change

In order to better respond to climate change challenges, we consolidated three new management areas in 2023: Water Resources, Competitiveness and Decarbonisation. With the commitment of these dedicated teams, at each of our four companies, we expect to accomplish and exceed our sustainability targets over the coming years.

Electromobility is essential to our decarbonisation strategy. We already operate the largest fleet of electric light trucks and auxiliary equipment at any mining site in Chile. This year, a total of 50 electric vehicles began work at Centinela, reducing Greenhouse Gas (GHG) emissions. In addition, the company acquired eight electric mining equipment to operate in the Esperanza Sur autonomous pit, resulting in a further reduction of 5,200 tonnes of CO2e annually. During the past year, in Los Pelambres, we evaluated starting a pilot implementation project involving electric-powered trolleys in the Las Hualtatas dump area, and will commence testing dynamic charging solutions for haul trucks during the first quarter of 2025.

In 2023, we introduced a new revised Scope 1 and 2 GHG emission reduction target to reduce Scope 1 and 2 emissions by 50% by the year 2035 against a 2020 baseline. Together with this, we introduced our first emission reduction target for Scope 3 emissions - to reduce Scope 3 emissions by 10% by the year 2030 using 2022 as a baseline for projecting emissions. In addition, in August 2023, Antofagasta Minerals, together with other major mining companies operating in Chile, formed the mining industry's first Scope 3 Emissions Traceability Roundtable.

As required by the Global Industry Standard on Tailings Management (GISTM), we completed compliance with the standard requirements at the El Mauro dam at Los Pelambres and the Centinela thickened tailings deposit (in the case of the last one, two years earlier than required) in August 2023. The implementation of the New Standard required the development of a preventive emergency plan with the community of Sierra Gorda (influence area of Centinela), which became the first municipality in Chile to have a natural hazard emergency simulation, and in Caimanes, a location 15 kilometres away from El Mauro tailings facility.

We are committed to responding to the world's challenges in the way that we do mining. We are adapting and focusing on critical and emerging issues that need to be addressed globally. As part of this, innovation plays a pivotal role in our industrial processes and competitiveness. It is embedded in our business and is a key driver of our long-term sustainability, particularly in our continued efforts to address the global challenge of climate change.

In a landmark step, we have patented Cuprochlor-T, which will allow us to extract lower-grade copper and extend the lifecycle of our mining deposits through innovative solutions for the production process. Innovation in our company also serves the safety of our people. We have increased the number of autonomous haul trucks and remotely operated mining drills across our operations, accompanied by training for all operators on our sites, which enables them to engage with these innovative technologies and minimises the possibility of accidents.

Centinela's Integrated Operations Management (GIO) project has been developed effectively during its second year of operation. The project consists of a remote centre in the Antofagasta Region from which the plant, mine and port activities can be controlled remotely using real-time data, significantly benefiting our people's safety, efficiency, and productivity levels. Los Pelambres has also implemented its own GIO centre, transferring critical milestones towards remote and integrated operation along the entire value chain. This involves the digitalisation and remotisation of operations and integrating centralised information systems, supported by workers' training for these tasks.

Suppliers

Our suppliers play a critical role in achieving our objectives. We support them collaboratively through our Suppliers for a Better Future programme with the tools they need to comply with sustainability standards concerning their performance, emissions reduction targets, and respect for human rights, among other issues that align with our corporate purpose. This initiative has provided national and regional suppliers with tools to increase competitiveness and their capacity for growth, helping them to incorporate themselves into the industry in an effective and efficient manner. This is particularly true for local small and medium-sized companies (SMEs) in the Antofagasta and Coquimbo regions.

Shared social value is key to our sustainable approach. We seek to contribute to social and economic development in the local communities in which we operate through proactive engagement based on trust, transparency, respect and acknowledgement of distinctiveness and diversity, collaborating with local organisations and authorities.

Our work contributes to a number of the United Nations Sustainable Development Goals (SDGs), mainly those regarding education, economic development, and deploying infrastructure. In 2023, more than 1,300 students benefited directly from our education programmes in the Antofagasta and Coquimbo regions; more than 650 micro and small businesses were assisted by the Cosecha and Emprende programmes in the Choapa Valey; and a newly reconstructed church and town square were inaugurated, following a year of work supported by Zaldívar, and in collaboration with the Atacama indigenous community of Camar.

As a leading mining company, we know that a long-term sustainable approach is critical to the continued creation of shared value. This is our focus. I invite you to explore our progress during 2023 in greater detail, and to discover the progress we are making in our economic, environmental, social and governance goals, to develop mining for

a better future.

IVÁN ARRIAGADA

Chief Executive Officer, Antofagasta Minerals

VIVIANNE BLANLOT

Chair

Sustainability and Stakeholder

Management Committee

Dear stakeholders,

I am pleased to present our 2023 Sustainability Report, underscoring our steadfast commitment to sustainable practices. Acknowledging the contributions of our directors, project teams, and stakeholders, who are integral to our objectives, we recognise the pivotal role

of environmental, social, and governance issues in driving sustainable growth, benefiting our organisation and society.

The relevance of these dimensions in our business is reflected in our governance and particularly in our Sustainability and Stakeholder Management Committee. This body oversees our performance on

community and environmental aspects based on our sustainability and human rights policies. This Committee supports the role of the Board and gives recommendations to ensure that sustainability matters are included in the Board's ongoing decision-making.

Antofagasta Minerals maintains regular dialogue with our stakeholders, and the Committee ensures their views are carefully considered in the Board's deliberations. We regularly review and update the Group's policy framework on safety, health, environment, human rights and community relations, and oversee the Group's performance in these subjects.

In 2023, the Committee reviewed topics such as our water strategy concerning our neighbouring communities, our environmental strategy, social programmes and our progress in health and safety. This key dimension has consistently demonstrated high standards by incorporating best practices, a corporate learning cycle and digital tools.

Given our role as a mining company in the energy transition and our long-term 2050 goal of carbon neutrality, we promoted our adherence to sustainability policies and standards to contribute to climate change adaptation. As members of the International Council on Mining and Metals (ICMM), we adhere to its sustainable development framework.

This consists of ten Mining Principles, each with a set of Performance Expectations in environmental, social and governance practices. In addition, our four operations meet all the criteria of The Copper Mark, an independent assurance framework for responsible copper industry mining practices.

Our Environmental Management Model addresses climate change aspects comprehensively. We seek to support our companies in the integrated implementation of the Model to identify and mitigate risks, and comply with the Group's environmental regulations. We advise on project design and improvement from the environmental and sustainability perspective, particularly regarding early dialogue with neighbouring communities.

Additionally, biodiversity and the circular economy have continued to be areas of focus for us. In 2023, we launched our Circular Economy Strategy, approved at the end of 2022. Our updated Biodiversity Standard was implemented and is aligned with the ICMM's position statement on Mining and Protected Areas.

Our people are at the centre of what we do

Health and safety are important issues for us. In 2023, we made progress in consolidating our management system by incorporating occupational health and safety planning into our operational model, to ensure the implementation of controls to prevent unwanted events. This framework applies to 100% of operations, our internal workforce, and contractors.

We are proud of having zero fatalities in 2023 and a reduction of 19% in High Potential Incidents. This demonstrates our company's commitment, particularly to the safety of our people on-site.

How we address climate change

Antofagasta strives to reduce its Greenhouse Gas (GHG) emissions in the short and medium term in line with our emissions reduction targets and our long-term ambition is to achieve carbon neutrality by 2050, or sooner if technology allows. In accordance with our Energy Policy framework, we incorporated the role of Energy Administrator at each mining site, along with a dedicated decarbonisation team.

In 2023, we released our second Climate Change Report, underscoring Antofagasta Minerals' commitment to sustainability and responsible business practices. In line with our company's dedication to transparency and accountability, the report provides a detailed overview of our efforts and progress in addressing climate change and reducing our environmental footprint. We disclosed our Scope 3 emissions inventory and established a new medium-term Scope 1 and 2 emissions reduction goal according to our new decarbonisation plan. We aim to reach a 50% reduction in emissions by 2035, with 2020 as a baseline. We also set a target to reduce Scope 3 emissions by 10% by 2030, which we aim to achieve through industry engagement.

As part of the third pillar of our Climate Change Strategy, water stewardship has become a critical aspect of our operations due to the nature and geographical location of our mining activities. In 2023, we assigned a water lead expert at each mining site to improve water management and increase efficiency. The green light for the Los Pelambres desalination plant expansion to 800 l/s by the Coquimbo region's Environmental Evaluation Commission exemplifies the relevance of the strategic value of water in our operations.

We support the development of the neighbouring communities

As Chair of the Sustainability and Stakeholder Management Committee, I am confident in our collective commitment to a sustainable future. Antofagasta Minerals will continue to evaluate priorities, foster initiatives in collaboration with our stakeholders, and work towards increasing the benefits of the mining industry across society.

VIVIANNE BLANLOT

Chair

Sustainability and Stakeholder Management Committee