Reserves & Resources

Notes on Mineral Resource and Mineral Reserve Tables

Mineral Resource and Mineral Reserve estimates are shown on a 100% basis. The Measured and Indicated Mineral Resource estimates are inclusive of those Mineral Resource estimates modified to produce the Mineral Reserve estimates. All estimates, with the exception of Chapada and Vicuña are effective as of December 31, 2025.  The effective date of Chapada is as of December 31, 2024 and the effective date of Vicuña is October 31, 2025.

Reference herein to $ or USD is to United States dollars, CLP is to Chilean pesos, BRL is to Brazilian real. Unless noted otherwise, Mineral Reserves for Candelaria and Caserones have been estimated using metal prices of $3.85/lb copper, $1,900/oz gold, $25/oz silver, and $17/lb molybdenum whereas Mineral Resources have been estimated using metal prices of $4.43/lb copper and $2,185/oz gold. Exchange rate used for Caserones and Candelaria was USD/CLP 900 for Mineral Reserve and Mineral Resource estimates. For the Vicuña (Josemaria and Filo del Sol) Mineral Resources, the metal prices used were $4.60/lb copper, $2,875/oz gold and $32.50/oz silver. Exchange rate used for Vicuna was USD/ARS 1,300 for Mineral Resources.

Mineral Reserves for Chapada have been estimated using metal prices of $3.85/lb copper, $1,600/oz gold, whereas Mineral Resources have been estimated using metal prices of $4.43/lb copper and $1,840/oz gold. Exchange rate used was USD/BRL 5.00 for Mineral Reserve and Mineral Resource estimates.

For a better understanding of each of the Company’s deposits readers are encouraged to read the technical reports and other public disclosure of the Company, including all qualifications, assumptions, exclusions and risks that relate to the Mineral Resource and Mineral Reserve estimates. The technical reports for the Company’s material projects are listed below, are intended to be read as a whole, and sections should not be read or relied upon out of context.

The Mineral Resource estimates for Lundin Mining sites were prepared under the supervision of and verified by Hamilton Matias, Registered Member of SME, Director, Resource Geology except for Chapada which were prepared under the supervision of and verified by Gustavo Campos, FAusIMM, Director Technical Services for Chapada Mine. For the Vicuña Project (Josemaria and Filo del Sol) the Mineral Resources were prepared independently by Mr. Sean Horan, P.Geo., Principal Resource Geologist of Resource Modelling Solutions Ltd.  (Josemaria) and Luke Evans, P.Eng., Global Technical Director, Geology Group Leader, SLR Consulting (Canada) Ltd. (Filo del Sol). Mineral Reserve estimates for Lundin Mining sites were prepared under the supervision of and verified by Claudio Araya, Director, Reserves and Mine Planning, Pedro Elissetche, Global Practice Lead, Reserves & Mine Planning, and Arthur Oppitz, FAusIMM, Technical Services Manager. They have also reviewed, verified and approved the technical and scientific information in this news release. No limitations were imposed on their verification process. Each of the aforementioned persons is a Qualified Person as defined under NI 43-101. Mineral Reserves for Vicuña (Josemaria and Filo del Sol) Project were declassified on April 15, 2025 as discussed in the NI 43-101 Technical Report Vicuña Project, Argentina and Chile, dated April 15, 2025.

Candelaria and Ojos del Salado

Candelaria and La Española open pit Mineral Resource estimates are reported within a conceptual pit shell with cut-off grades of 0.12% and 0.14% copper, respectively. Underground Mineral Resources are estimated at cut-off grades of 0.39% and 0.42% copper for Candelaria underground and Ojos del Salado, respectively. Mineral Reserves for the Candelaria open pit, Española open pit, and Candelaria underground are estimated at cut-off grades of 0.14%, 0.16% and 0.45% copper, respectively. Mineral Reserves for the Santos mine at Ojos del Salado is estimated at a cut-off grade of 0.48% copper. Claudio Araya, Director, Reserves and Mine Planning, Lundin Mining has reviewed and verified the Mineral Reserves estimates.

For further information on Candelaria, refer to the Technical Report entitled Technical Report for the Candelaria Copper Mining Complex, Atacama Region, Region III, Chile”, dated February 22, 2023, which is filed under the Company’s profile on SEDAR+ at www.sedarplus.ca.

Caserones

Caserones Mineral Resource estimates are reported within a conceptual pit shell using NSR cut-off values of $13.37/t mineralized material processed at concentrating and $4.28/t for dump leach mineralized material. Mineral Reserves for the Caserones open pit are estimated using open pit discard NSR cut-off values of $13.37/t for ore processed at concentrating and $4.28/t for ore delivered to the heap leach and SX/EW processing. Hamilton Matias, Director, Resource Geology, Lundin Mining has reviewed and verified the Mineral Resources estimates, and Pedro Elissetche, Global Practice Lead, Reserves & Mine Planning, Lundin Mining has reviewed and verified the Mineral Reserves estimates.

For further information on Caserones, refer to the Technical Report entitled NI 43-101 Technical Report on the Caserones Mining Operation, Atacama Region, Chile, dated July 13, 2023 which is filed under the Company’s profile on SEDAR+ at www.sedarplus.ca.

Chapada

The Chapada Mineral Resource estimates are reported within a conceptual pit shell at an open pit discard NSR cut-off value of $6.26/t. For Suruca, an NSR cut-off value of $6.80/t was used for oxide (heap leach) and sulphide portion, and $11.42/t for oxide (carbon-in-leach). Mineral Reserves are estimated using open pit discard NSR cut-off values of $6.26/t for the Chapada open pit.  The Saúva open pit Mineral Resource estimates are reported within a conceptual pit shell with NSR cut-off value of $7.12/t. Saúva underground Mineral Resources are reported within optimized stope volumes with an NSR cut-off value of $34.50/t. Mr. Gustavo Campos, FAusIMM, Director Technical Services for Chapada mine has reviewed and verified the Mineral Resources for Chapada, Suruca and Saúva. Mr. Arthur Oppitz, FAusIMM, Technical Services Manager, Lundin Mining has reviewed and verified the Mineral Reserves estimates.

For further information on Chapada, refer to the NI 43-101 Technical Report entitled Independent Technical Report for the Chapada Mine and Saúva Copper-Gold Project, Northern Goiás State, Brazil, dated February 19, 2025 which is filed under the Company’s profile on SEDAR+ at www.sedarplus.ca.

Vicuña

Mineral Resources are reported in situ. The Filo del Sol estimates were current at December 31, 2025, and the Josemaría estimates were current at December 31, 2025. Mineral Resources are reported on a 100% basis. The Project is a 50:50 joint venture between Lundin Mining and BHP Canada. Lundin Mining’s attributable interest in the Mineral Resource estimate is 50%. The Qualified Person for the Filo del Sol estimates is Mr. Luke Evans, M.Sc., P.Eng., an SLR Consulting (Canada) Ltd. employee. The Qualified Person for the Josemaría estimate is Mr. Sean D. Horan, P.Geo., a Resource Modelling Solutions Ltd. employee.

The Vicuña Mineral Resource estimate was prepared using commercial mine software and geostatistical software. The Mineral Resource estimates for Filo del Sol and Josemaria deposits are based on 224,849 m of drilling in 435 drill holes and 106,504 m in 243 drill holes, respectively. The holes were assayed on a nominal 2-metre basis.  Assays were composited (8 m for Filo del Sol and 4 m for Josemaria) and top-cut (Filo del Sol only) prior to interpolation. The deposits were segregated into multiple estimation domains based on the geological models of lithology, alteration and mineralization style. Density was assigned by using an average per estimation domain for Filo del Sol and simulated for Josemaria, based on the results of specific-gravity samples taken from the drill core. The geological database was closed on October 31, 2025 for Filo del Sol and December 31, 2022 for Josemaria.

Metal grades were interpolated using top-cut Ordinary Kriging for Filo del Sol and conditional simulation for Josemaria. Search ellipse anisotropy and orientation were guided by variography and geology. Mineral Resources are classified under the categories of Measured, Indicated, and Inferred according to the CIM Standards. Blocks were coded with the average distance to the nearest three drillholes, and the Mineral Resource classification was based primarily on drill hole spacing with consideration for the continuity of mineralization. Final classification shapes were smoothed by post-processing.

Metallurgical testing demonstrates that oxide mineralization at Filo del Sol is amenable to heap leach operations to produce copper cathode and gold/silver doré. Hypogene mineralization at Josemaria and Filo del Sol are considered amenable to conventional milling and flotation to produce copper concentrates. At Josemaria, average flotation recoveries of 82%, 60% and 56% are expected for copper, gold and silver, respectively. At Filo del Sol, flotation recoveries vary by material type.  In the Filo del Sol concentrator, overall average recoveries of 78%, 62% and 62% are expected for copper, gold and silver, respectively. In the Filo del Sol heap leach, recoveries of 67%, 63% and 78% are expected for copper, gold and silver, respectively. Recovery estimates consider metallurgical testwork completed up to January 13, 2025.

This Mineral Resource estimate is also based upon the reasonable prospect of eventual economic extraction based on an optimized pit, using cost assumptions consistent with the integrated Preliminary Economic Assessment. The pit optimization results are used solely for testing the "reasonable prospects for eventual economic extraction" and do not represent an attempt to estimate Mineral Reserves.  Conceptual pits for both deposits were generated using $4.60/lb. Cu, $2,875/oz. Au, and $32.50/oz. Ag. Maximum pit slope angle is 45 degrees for Filo del Sol and 45 degrees for Josemaria. At Josemaria, an average mining cost of $1.86/t with incremental costs of $0.049/t/bench are used. At Filo del Sol, an average mining cost of $1.64/t with incremental cost of $0.049/t/bench are used. Average processing costs are estimated at $4.48/t at Josemaria and range from $4.74 to $14.13/t at Filo. G&A cost estimates for both deposits are $1.64/t.

Filo del Sol copper equivalent (CuEq) assumes average metallurgical recoveries of 78% for copper, 62% for gold and 62% for silver, and metal prices of $4.60/lb Cu, $2,875/oz Au and $32.50/oz Ag. The CuEq formula is: CuEq= Cu% + (0.73 * Au g/t) + (0.009 * Ag g/t).

For further information on Vicuña, refer to the news release entitled “Lundin Mining Announces Vicuña Integrated Technical Study Results Highlighting a World Class Mining District” dated February 16, 2026 which is filed under the Company’s profile on SEDAR+ at www.sedarplus.ca.