Lundin Mining Reports on Civil Claim Pertaining to the 2022 Sinkhole at the Alcaparrosa Mine

VANCOUVER, BC, Sept. 8, 2025 /PRNewswire/ -- (TSX: LUN) (Nasdaq Stockholm: LUMI) Lundin Mining Corporation ("Lundin Mining" or the "Company") has received notice regarding the decision on the civil claim brought by the Chilean State Defense Council (CDE) against Lundin Mining's subsidiary, Minera Ojos del Salado ("Ojos del Salado"), related to the sinkhole that occurred near the Company's Alcaparrosa mine in July 2022. View PDF version

The decision requires Ojos del Salado to implement remediation activities on the impacted area, including but not limited to the backfilling of the sinkhole, the facilitation of recharging the aquifer, ongoing monitoring requirements and the transfer of certain ground water rights. In addition, Ojos del Salado is required to implement water infrastructure projects to strengthen rural potable water and wastewater systems in communities surrounding the mine.

Throughout the process the Company has collaborated with investigative proceedings initiated by sectoral regulators, including providing monitoring technology, studies and experts to provide information and ensure the stability of the sinkhole. The Company will work with authorities and stakeholders to clarify details and timelines of the remediation activities included in the decision while it determines its next steps.

Mining operations at Alcaparrosa have been suspended since the sinkhole incident occurred in July 2022. At the time, Mineral Reserve estimates for the Alcaparrosa mine were removed from the Company's reserve statement and have not been included in any future production estimates. The Company's Candelaria operation is unaffected and is forecast to produce 140,000 tonnes to 150,000 tonnes of copper in 2025.

About Lundin Mining

Lundin Mining is a diversified Canadian base metals mining company with projects or operations focused in Argentina, Brazil, Chile and the United States of America, and primarily producing copper, gold and nickel.

The information in this release is subject to the disclosure requirements of Lundin Mining under the Swedish Financial Instruments Trading Act. The information was submitted for publication, through the agency of the contact persons set out below on September 7, 2025 at 20:30 Pacific Time.

Cautionary Statement on Forward-Looking Information

Certain of the statements made and information contained herein are "forward-looking information" within the meaning of applicable Canadian securities laws. All statements other than statements of historical facts included in this document constitute forward-looking information, including but not limited to statements regarding the decision on the civil claim brought by the Chilean State Defense Council related to the sinkhole that occurred near the Company's Alcaparrosa mine in July 2022, its impact on the Company and its operations, and the Company's actions in relation to the decision, including remediation actions and timelines; the Company's guidance on the timing and amount of future production and its expectations regarding the results of operations; and the timing and possible outcome of pending litigation, civil proceedings and regulatory proceedings, and appeals thereof; Words such as "believe", "expect", "anticipate", "contemplate", "target", "plan", "goal", "aim", "intend", "continue", "budget", "estimate", "may", "will", "can", "could", "should", "schedule" and similar expressions identify forward-looking information.

Forward-looking information is necessarily based upon various estimates and assumptions including, without limitation, the expectations and beliefs of management, including that the Company can access financing, appropriate equipment and sufficient labour; assumed and future price of copper, gold, zinc, nickel and other metals; anticipated costs; currency exchange rates and interest rates; ability to achieve goals; the prompt and effective integration of acquisitions and the realization of synergies and economies of scale in connection therewith; that the political, economic, permitting and legal environment in which the Company operates will continue to support the development and operation of mining projects; timing and receipt of governmental, regulatory and third party approvals, consents, licenses and permits and their renewals; positive relations with local groups; the accuracy of Mineral Resource and Mineral Reserve estimates and related information, analyses and interpretations; and such other assumptions as set out herein as well as those related to the factors set forth below. While these factors and assumptions are considered reasonable by Lundin Mining as at the date of this document in light of management's experience and perception of current conditions and expected developments, such information is inherently subject to significant business, economic, political, regulatory and competitive uncertainties and contingencies. Known and unknown factors could cause actual results to differ materially from those projected in the forward-looking information and undue reliance should not be placed on such information. Such factors include, but are not limited to: dependence on international market prices and demand for the metals that the Company produces; political, economic, and regulatory uncertainty in operating jurisdictions, including but not limited to those related to permitting and approvals, nationalization or expropriation without fair compensation, environmental and tailings management, labour, trade relations, and transportation; operating jurisdictions, including but not limited to those related to permitting and approvals, nationalization or expropriation without fair compensation, environmental and tailings management, labour, trade relations, and transportation; risks relating to mine closure and reclamation obligations; health and safety hazards; inherent risks of mining, not all of which related risk events are insurable; risks relating to tailings and waste management facilities; risks relating to the Company's indebtedness; challenges and conflicts that may arise in partnerships and joint operations; risks relating to development projects, including Filo del Sol and Josemaria; risks that revenue may be significantly impacted in the event of any production stoppages or reputational damage in Chile; the impact of global financial conditions, market volatility and inflation; business interruptions caused by critical infrastructure failures; challenges of effective water management; exposure to greater foreign exchange and capital controls, as well as political, social and economic risks as a result of the Company's operation in emerging markets; risks relating to stakeholder opposition to continued operation, further development, or new development of the Company's projects and mines; any breach or failure information systems; risks relating to reliance on estimates of future production; risks relating to litigation and administrative proceedings which the Company may be subject to from time to time; risks relating to acquisitions or business arrangements; risks relating to competition in the industry; failure to comply with existing or new laws or changes in laws; challenges or defects in title or termination of mining or exploitation concessions; the exclusive jurisdiction of foreign courts; the outbreak of infectious diseases or viruses; risks relating to taxation changes; receipt of and ability to maintain all permits that are required for operation; minor elements contained in concentrate products; changes in the relationship with its employees and contractors; the Company's Mineral Reserves and Mineral Resources which are estimates only; uncertainties relating to inferred Mineral Resources being converted into Measured or Indicated Mineral Resources; payment of dividends in the future; compliance with environmental, health and safety laws and regulations, including changes to such laws or regulations; interests of significant shareholders of the Company; asset values being subject to impairment charges; potential for conflicts of interest and public association with other Lundin Group companies or entities; activist shareholders and proxy solicitation firms; risks associated with climate change; the Company's common shares being subject to dilution; ability to attract and retain highly skilled employees; reliance on key personnel and reporting and oversight systems; risks relating to the Company's internal controls; counterparty and customer concentration risk;  risks associated with the use of derivatives; exchange rate fluctuations; the terms of the contingent payments in respect of the completion of the sale of the Company's European assets and expectations related thereto; the earn-in arrangement in respect of the Boulderdash properties, including the entering into of an option agreement in respect thereof and the terms of such option agreement; future actions taken by Talon Metals Corp. and Lundin Mining in relation to the Boulderdash properties and the outcomes and anticipated benefits thereof; and other risks and uncertainties, including but not limited to those described in the "Risks and Uncertainties" section of the Company's MD&A for the three and six months ended June 30, 2025, the "Risks and Uncertainties" section of the Company's MD&A for the year ended December 31, 2024, and the "Risks and Uncertainties" section of the Company's Annual Information Form for the year ended December 31, 2024, which are available on SEDAR+ at www.sedarplus.ca under the Company's profile.

All of the forward-looking information in this document is qualified by these cautionary statements. Although the Company has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking information, there may be other factors that cause results not to be as anticipated, estimated, forecasted or intended and readers are cautioned that the foregoing list is not exhaustive of all factors and assumptions which may have been used. Should one or more of these risks and uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those described in forward-looking information. Accordingly, there can be no assurance that forward-looking information will prove to be accurate and forward-looking information is not a guarantee of future performance. Readers are advised not to place undue reliance on forward-looking information. The forward-looking information contained herein speaks only as of the date of this document. The Company disclaims any intention or obligation to update or revise forward ‐  looking information or to explain any material difference between such and subsequent actual events, except as required by applicable law.