Mr. Stephen Williams reports

LUNDIN MINING ANNOUNCES 2023 MINERAL RESOURCE AND MINERAL RESERVE ESTIMATES

Lundin Mining Corp. has released its mineral resource and mineral reserve estimates effective as of Dec. 31, 2023 (or otherwise specified herein). On a 100-per-cent consolidated basis, the estimated proven and probable mineral reserve of contained copper is 10,630 kt (23.4 Blb) an increase of 2,220 kt (4.9 Blb) over the previous year. Lundin Mining also has significant Proven and Probable Mineral Reserves in other base and precious metals including 2,554 kt (5.6 Blb) of zinc, 51 kt (112 Mlb) of nickel, 12.0 Moz of gold, and 157.0 Moz of silver.

Proven & Probable Copper Reserves     
   In thousands of tonnes (kt)       
   
2022 Copper Reserves (P&P)  8,410    
Depletion                   (-) 482  
Acquisition                 (+) 2,550
Net Revisions               (+) 152  
2023 Copper Reserves (P&P)  10,630   

Net revisions (increases/decreases) are primarily the result of changes to mining regulations that impacted underground geotechnical parameters at Candelaria and additions from exploration and resource input updates at Caserones.

Jack Lundin, President and CEO, commented "This year, we grew our Mineral Reserve base through the strategic acquisition of Caserones, which contributed to an increase in our overall Proven and Probable copper Reserves by 26% on a 100% basis. Since the acquisition the Company has added an additional 350 kt of copper Proven and Probable Mineral Reserves at Caserones. We have also initiated the first significant exploration drill program at Caserones since the mine began operating in 2013 targeting Mineral Resources and mine life extension.

At Candelaria, additional drilling at La Espanola and Santos contributed to an increase in overall Mineral Resources, offsetting changes to underground mining regulations which have impacted underground Mineral Resources.

The additional drilling at the Sauva deposit in 2023 grew the Measured and Indicated copper Mineral Resources by 25%, Sauva now contains a Measured and Indicated Mineral Resource of 245 Mt at 0.29% copper and 0.17 g/t gold. We will continue to evaluate options for future processing, which might include, among other options, integrating this material into Chapada's processing facility.

At Neves-Corvo and Zinkgruvan, infill drilling campaigns successfully replaced Mineral Reserve depletion from mining during the year."

Mineral Resource and Mineral Reserve Highlights

• Candelaria (Chile): Mineral Reserve reductions at Candelaria were primarily driven by depletion from production and new geotechnical constraints for underground mining. Decreases were partially offset by the addition of Mineral Reserves at La Espanola, Santos and the Candelaria main pit. The underground expansion project ("CUGEP") will be evaluated to include changes in the geotechnical parameters recommended by the local authorities. A total of 42,190 metres were drilled for exploration purposes at Candelaria underground (north and south), Candelaria west and south extensions, and at Santos.
• Caserones (Chile): Caserones Mineral Reserves and Mineral Resources increased from higher metal price forecasts, block model updates and changes to Mineral Resource classification.
• Chapada (Brazil): Mineral Reserve changes were mainly the result of mine depletion, updated metallurgical recoveries and increased operating cost assumptions. Total exploration drilling at Chapada for 2023 was 23,614 metres, primarily focused on Baru northeast, Chapada southwest, Cava Norte, Sucupira and Corpo Sul.
• Sauva (Brazil): The deposit, which is located approximately 15 km north of Chapada, remains open in all directions. Additional drilling during the year tested step-out anomalies along the broader Sauva-Formiga trend which contributed to an increase in Mineral Resources. The Sauva deposit increased by 25% from 578 kt to 721 kt of copper in the Measured and Indicated Mineral Resource categories.
• Eagle (USA): The increase in Mineral Reserves at Eagle is primarily due to the increase in metal price assumptions and a change in mining method in the Keel zone which extends the mine life into 2029. Lower cut-off grades from the application of bulk mining methods have decreased average head grades.
• Neves Corvo (Portugal): Mineral Reserves remain in-line with last year's estimate. Conversion of previously Inferred Mineral Resources has helped offset mining depletion during the year. In 2023, exploration drilling focused on extending near-mine mineralization. A total of 29,635 metres of exploration drilling were completed in 2023.
• Zinkgruvan (Sweden): Additions to Mineral Reserves at Zinkgruvan were primarily driven by increases in metal prices, improvement in metallurgical recovery, and Mineral Resource conversion from infill drilling. In 2023, exploration drilling at Zinkgruvan was primarily focused on near-mine expansion along known mineralized trends. A total of 31,820 metres were drilled from underground and surface targeting extensions of known resources.

Mineral Resource and Reserve Summary

The tables below summarize the Mineral Resource and Mineral Reserve estimates for each of the Company's sites effective as of December 31, 2023 on a 100% basis (or otherwise stated therein), important information is included in the notes following this news release. Table totals may not summate correctly due to rounding. Mineral Resources are inclusive of Mineral Reserves. For more information on the prior Mineral Resource and Mineral Reserve estimates for each of the Company's sites effective as of December 31, 2022 that are referred to herein please see the news release dated February 8, 2023, which is available on the Company's SEDAR+ profile and on the Company's website.

About Lundin Mining

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

Cautionary Notes to Investors - Mineral Resource and Reserve Estimates

In accordance with applicable Canadian securities laws, all Mineral Reserve and Mineral Resource estimates of the Company disclosed or referenced in this news release have been prepared in accordance with the disclosure standards of Canadian National Instrument 43-101 - Standards of Disclosure for Mineral Projects of the Canadian Securities Administrators ("NI 43-101"), and have been classified in accordance with Canadian Institute of Mining Metallurgy and Petroleum's "Definition Standards for Mineral Resources and Reserves" (the "CIM Standards"). Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.

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 Josemaria are effective as at December 31, 2023. The Josemaria Mineral Resource estimates are effective as at July 10, 2020 and the Mineral Reserve estimates are effective as at September 28, 2020.

Reference herein to $ or USD is to United States dollars, CLP is to Chilean pesos, BRL is to Brazilian real, EUR refers to euros, and SEK is to Swedish kronor. Unless noted otherwise, Mineral Reserves for all active mines have been estimated using metal prices of $3.65/lb copper, $1.15/lb zinc, $0.90/lb lead, $10.0/lb nickel and $1,600/oz gold, whereas Mineral Resources have been estimated using metal prices of $4.20/lb copper and $1,840/oz gold. Exchange rates used were EUR/USD 1.10, USD/SEK 9.00, USD/CLP 800 and USD/BRL 5.00 for Mineral Reserve and Mineral Resource estimates. For the Josemaria Mineral Reserve, the metal prices used were $3.00/lb copper, $1,500/oz gold and $18.00/oz silver.

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 are listed below, are intended to be read as a whole, and sections should not be read or relied upon out of context.

Unless noted otherwise, the Mineral Resource and Mineral Reserve estimates were prepared under the supervision of and verified by Cole Mooney, P.Geo., Director, Resource Geology, and Arkadius Tarigan, P.Eng., former Director, Reserves and Mine Planning, respectively for all sites below. They have also reviewed, verified and approved the technical and scientific information in this news release. No limitations were imposed on their verification process. Both Messrs. Mooney and Tarigan are Qualified Persons as defined under NI 43-101.

Candelaria and Ojos del Salado

Candelaria and La Espanola open pit Mineral Resource estimates are reported within a conceptual pit shell with cut-off grades of 0.13% and 0.15% copper, respectively. Underground Mineral Resources are estimated at cut-off grades of 0.38% and 0.47% copper for Candelaria underground and Ojos del Salado, respectively. Mineral Reserves for the Candelaria open pit, Espanola open pit, and Candelaria underground are estimated at cut-off grades of 0.14%, 0.16% and 0.44% copper, respectively. Mineral Reserves for the Santos mine at Ojos del Salado is estimated at a cut-off grade of 0.51% copper.

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+.

Caserones

Caserones Mineral Resource estimates are reported within conceptual pit shell using a cut-off grade of 0.13% copper. Mineral Reserves for the Caserones open pit are estimated using open pit discard NSR cut-off values of $11.70/t for ore processed at concentrating and $3.65/t for ore delivered to the heap leach and SX/EW processing.

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+.

Chapada

The Chapada and Suruca copper-gold Mineral Resource estimates are reported within a conceptual pit shell at an open pit discard NSR cut-off value of $5.80/t. For the Suruca copper-gold, 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). For the Suruca gold only Mineral Resource estimates, NSR cut-off values of $6.80/t for oxides and $11.42/t for mixed and sulphide were used. Mineral Reserves are estimated using open pit discard NSR cut-off values of $5.80/t and $6.80/t for the Chapada open pit and Suruca gold oxides respectively.

For further information on Chapada, refer to the Technical Report entitled Technical Report on the Chapada Mine, Goias State, Brazil, dated October 10, 2019 which is available on Lundin Mining's SEDAR+ profile.

Eagle

The Eagle Mineral Resource and Mineral Reserve estimates are reported using NSR cut-off values of $143.9/t, $150.4/t, $176.4/t and $151.2/t for Eagle, Upper Keel and Eagle East cut and fill and stope zones, respectively. The NSR is calculated on a recovered payable basis considering nickel, copper, cobalt, gold and PGM grades, metallurgical recoveries, prices and realization costs.

Josemaria

The Josemaria open pit Mineral Resource estimates are reported within a conceptual pit shell based on metal prices of $3.00/lb copper, $1,500/oz gold and $18.00/oz silver with a cut-off grade of 0.10% copper. Mineral Reserve estimates for Josemaria are estimated at NSR cut-off values ranging from $5.16/t to $5.22/t, based on metallurgical unit. Mr. Dustin Smiley, P.Eng., Manager, Mine Engineering and Costing, Lundin Mining reviewed and verified the Mineral Reserves estimates for Josemaria project.

For further information on Josemaria, refer to the Technical Report entitled NI 43-101 Technical Report, Feasibility Study for the Josemaria Copper-Gold Project, San Juan Province, Argentina dated November 5, 2020, which is available on the Company's subsidiary, Josemaria Resources Inc.'s SEDAR+ profile.

Neves-Corvo and Semblana

The copper Mineral Resource estimates are reported within geological volumes based on a nominal cut-off grade of 1.0% copper and the zinc Mineral Resource estimates are reported within geological volumes based on a nominal zinc cut-off grade of 4.5% zinc. The copper and zinc Mineral Reserve estimates have been calculated using variable NSR values ranging from euros49/t to euros82/t based on mineralization, areas and mining methods. The NSR is calculated on a recovered payable basis considering copper, lead, zinc and silver grades, metallurgical recoveries, prices and realization costs.

The Mineral Resources at Semblana are estimated above a cut-off grade of 1.0% copper.

For further information on Neves-Corvo and Semblana, refer to the Technical Report entitled NI 43-101 Technical Repot on the Neves-Corvo Mine, Portugal, dated February 22, 2023 which is filed under the Company's profile on SEDAR+.

Sauva

The Sauva open pit Mineral Resource estimates are reported within a conceptual pit shell with NSR cut-off value of $7.80/t.

Zinkgruvan

The zinc and lead Mineral Resources are estimated within optimized stope volumes, using a 3.5 m minimum mining width, based on an area dependent marginal NSR cut-off between SEK 740/t and SEK 920/t. The copper Mineral Resource estimates are reported within optimized stope volumes above a cut-off NSR values ranging from SEK 800/t to SEK 830/t. The zinc and copper Mineral Reserves are estimated at NSR cut-off values ranging from SEK 950/t to SEK 1,100/t depending on the mineralization, areas and mining methods. The NSR is calculated on a recovered payable basis considering copper, lead, zinc and silver grades, metallurgical recoveries, prices and realization costs.

We seek Safe Harbor.