Ero Copper Corp. (TSX: ERO) (NYSE: ERO) is pleased to announce an update of its National Instrument 43-101 compliant mineral reserve and resource estimates for its Xavantina Operations, located in Mato Grosso State, Brazil. The updated mineral reserve and mineral resource estimates incorporate drilling activities and mining depletion on the properties through June 30, 2024.

HIGHLIGHTS

• 19% increase in proven and probable mineral reserves as compared to the 2023 estimate, including a 24% increase at the Santo Antônio Vein.
• Proven and probable mineral reserve compound annual growth rate of approximately 62% from 2018 to 2024.
• 26% increase in measured and indicated mineral resources, inclusive of mineral reserves, as compared to the 2023 estimate, including a 31% increase at the Santo Antônio Vein.
• Excess mill capacity of approximately 25% continues to offer further expansion potential in the near- and medium-term.

“Our ongoing exploration program at the Xavantina Operations continues to deliver exceptional results,” stated David Strang, Chief Executive Officer. “When we acquired this asset in 2016, it had no mineral reserves, no mine life, and annual production of just 25,000 ounces. We have since transformed it into a robust operation with nearly 600,000 ounces of measured and indicated resources, including 459,000 ounces of proven and probable reserves. The successful completion of our NX 60 Initiative in 2023, highlighted by first production from the Matinha Vein, was a major milestone, positioning Xavantina to sustain annual production of approximately 55,000 to 60,000 ounces in the years ahead.

“We are equally excited about Xavantina’s untapped potential, both near the mine and regionally. Our dual strategy remains focused on extending mine life and discovering new vein structures to expand mine and mill feed, enabling us to fully utilize the mill’s installed capacity of up to 300,000 tonnes per annum.”

Xavantina Operations Proven & Probable Mineral Reserve Evolution Since IPO

Note: Mineral reserve estimates were prepared in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definition Standards for Mineral Resources and Mineral Reserves, adopted by the CIM Council on May 10, 2014 (the “CIM Standards”), and the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines, adopted by CIM Council on November 29, 2019 (the “CIM Guidelines”), using geostatistical and/or classical methods, plus economic and mining parameters appropriate for the deposit. Please refer to the Notes on Mineral Reserves and Mineral Resources section of this press release for a discussion on the assumptions, parameters and methods used to estimate the mineral reserves for 2024. 2024 mineral reserve estimate effective date of June 30, 2024. Please see the 2018 Xavantina Technical Report, the 2019 Xavantina Technical Report, the 2020 Xavantina Technical Report, the January 2022 Press Release, the 2022 Xavantina Technical Report and the 2023 AIF, as applicable and as defined below, for a discussion on the assumptions, parameters and methods used to estimate the mineral reserves for 2018, 2019, 2020, 2021, 2022 and 2023, respectively. All figures have been rounded to the relative accuracy of the estimates.

2024 MINERAL RESERVE AND RESOURCE ESTIMATE

_{Note: 2024 mineral reserve and resource estimates are effective as at June 30, 2024. 2023 mineral reserve and resource estimates are effective as at December 31, 2023. Presented mineral resources are inclusive of mineral reserves. All figures have been rounded to reflect the relative accuracy of the estimates. Summed amounts may not add due to rounding. Mineral resources that are not mineral reserves do not have a demonstrated economic viability. See below notes on mineral reserve and resource estimates for additional technical and scientific information.}

NOTES ON MINERAL RESERVES AND RESOURCES

The 2024 mineral reserve and mineral resource estimates are effective as at June 30, 2024. Mineral resources are presented, including mineral reserves. All figures have been rounded to the relative accuracy of the estimates. Summed amounts may not add due to rounding. Mineral resources that are not mineral reserves do not have a demonstrated economic viability.

The 2024 mineral reserve and resource estimates for the Xavantina Operations are prepared under the supervision of and verified by Mr. Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) and Resource Manager of the Company who is a “qualified person” within the meanings of NI 43-101.

Reference herein of $ or USD is to United States dollars and BRL is to Brazilian reais. Mineral Reserves for the Xavantina Operations have been estimated using a gold price of $1,900/oz, and the exchange rate used for mineral reserve and resource estimates was USD/BRL 5.10.

Grade shells using a value of 1.20 gpt gold were used to generate a 3D mineralization model of the Xavantina Operations. Within the grade shells, mineral resources were estimated using ordinary kriging within 10 meter by 10 meter by 2 meter block size, with a minimum sub- block size of 1.0 meter by 1.0 meter by 0.5 meter, and the mineral resource estimate was constrained using a minimum stope dimension of 2.0 meters by 2.0 meters by 1.5 meters, a cut-off of 1.20 gpt based on underground mining and processing costs of US$72 per tonne and a gold price of US$1,900 per ounce.

The 2024 mineral reserve estimates were prepared in accordance with the CIM Standards and the CIM Guidelines, using geostatistical and/or classical methods, plus economic and mining parameters appropriate for the deposit. Mineral reserves are the economic portion of the measured and indicated mineral resources. Mineral reserve estimates include operational dilution of 17.4% plus planned dilution of approximately 8.5% within each stope for room- and-pillar mining areas and operational dilution of 3.2% plus planned dilution of 21.2% for cut-and-fill mining areas. Mining recovery of 92.5% and 94.7% assumed for room-and-pillar and cut-and-fill areas, respectively. Practical mining shapes (wireframes) were designed using geological wireframes / mineral resource block models as a guide.

Where applicable, for scientific and technical information on historic mineral resource and reserve estimates on the Xavantina Operations, please refer to the following reports:

• The “Xavantina Operations – Update Information with respect to the Xavantina Operations” section within the Company’s 2023 Annual Information Form dated March 7, 2024, prepared under the supervision of and verified by Mr. Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) and Resource Manager of the Company for technical information and assumptions related to the 2023 mineral reserve and mineral resource estimate, with an effective date of December 31, 2023.

• The NI 43-101 technical report entitled “Technical Report on the Xavantina Operations, Mato Grosso, Brazil” dated May 12, 2023 with an effective date of October 31, 2022, prepared by Porfirio Cabaleiro Rodrigues, FAIG, Leonardo de Moraes Soares, MAIG and Guilherme Gomides Ferreira, MAIG, all of GE21 Consultoria Mineral Ltda. for technical information and assumptions related to the 2022 mineral reserve and mineral resource estimate.

• The Company’s Press Release dated January 6, 2022, for technical information and assumptions related to the 2021 mineral reserve and mineral resource estimate, with an effective date of September 30, 2021 prepared by or under the supervision of and verified by Mr. Emerson Ricardo Re, MSc, MBA, MAusIMM (CP) (No. 305892), Registered Member (No. 0138) (Chilean Mining Commission) and Resource Manager of the Company as at the date of the press release, who was a Qualified Person as such term is defined under NI 43-101.

• The NI 43-101 technical report entitled “Mineral Resource and Mineral Reserve Estimate of the NX Gold Mine, Nova Xavantina” dated January 8, 2021, with an effective date of September 30, 2020, prepared by Porfirio Cabaleiro Rodriguez, MAIG, Leonardo de Moraes Soares, MAIG, Bernardo Horta Cerqueira Viana, MAIG, Paulo Roberto Bergmann, FAusIMM, all of GE21 for technical information and assumptions related to the 2020 mineral reserve and mineral resource estimate.

• The NI 43-101 technical report entitled “Mineral Resource and Mineral Reserve Estimate of the NX Gold Mine, Nova Xavantina” dated February 3, 2020 with an effective date of September 30, 2019, prepared by Porfirio Cabaleiro Rodrigues, FAIG, Leonardo de Moraes Soares, MAIG and Paulo Roberto Bergmann, all of GE21 for technical information and assumptions related to the 2019 mineral reserve and mineral resource estimate.

• The NI 43-101 technical report entitled “Mineral Resource and Mineral Reserve Estimate of the NX Gold Mine, Nova Xavantina” dated January 21, 2019 with an effective date of August 31, 2018, prepared by Porfirio Cabaleiro Rodrigues, FAIG, Leonardo Apparicio da Silva, MAIG and Leonardo de Moraes Soares, MAIG, all of GE21 for technical information and assumptions related to the 2018 mineral reserve and mineral resource estimate.

QUALIFIED PERSONS

Mr. Cid Gonçalves Monteiro Filho, SME RM (04317974), MAIG (No. 8444), FAusIMM (No. 329148) has reviewed, verified and approved the scientific and technical information contained in this press release, including the sampling, analytical and test data underlying the information contained in this press release. Mr. Monteiro is Resource Manager of the Company and is a “qualified person” within the meanings of NI 43-101.

QUALITY ASSURANCE & QUALITY CONTROL

Current QA/QC Program

At the Xavantina Operations, the Company is currently drilling underground with third-party contracted core drill rigs. During the period from October 2022 to June 2024, third party drill rigs were operated by Trust Drilling Solutions and Servitec Foraco Sondagem S.A. who are independent of the Company. Drill core is logged, photographed and split in half using a diamond core saw at our secure core logging and storage facilities. Half of the drill core is retained on site and the other half-core is used for analysis, with samples collected on a minimum of 0.2 meters and a maximum of 2.0 meters with an average length of 0.5 meters. Sampling commences at least 1.0 meter before the start of the mineralized zone and continues at least 1.0 meter beyond the limit of the mineralized zone. Sample collection is performed at our core logging facilities with all sample preparation performed at ALS Brasil Ltda.’s laboratory or SGS Geosol – Laboratórios Ltda’s laboratory, both of which are located in Goiânia, Brazil. Samples are analyzed by the certified laboratories of ALS Peru S.A. or SGS Geosol – Laboratórios Ltda, both of whom are independent of the Company. Gold content is preferentially determined using screen fire assay. If the sample isn’t sufficiently weighted, fire assay is used. All sample results used in the preparation of the 2024 updated mineral resource and reserve estimate have been monitored through a quality assurance and quality control program that includes the insertion of certified standards, blanks and field duplicates at a rate of one standard, one blank, and one field duplicate sample per every 20 samples for a blended rate of approximately 5%.

QA/QC Validation

The QA/QC validation process undertaken for the 2024 updated mineral resource and reserve estimates for the Xavantina Operations is consistent with the process set out in the 2022 Xavantina Technical Report.

ABOUT ERO COPPER CORP

Ero Copper is a high-margin, high-growth copper producer with operations in Brazil and corporate headquarters in Vancouver, B.C. The Company’s primary asset is a 99.6% interest in the Brazilian copper mining company, Mineração Caraíba S.A., 100% owner of the Company’s Caraíba Operations, which are located in the Curaçá Valley, Bahia State, Brazil, and the Tucumã Operation, an open pit copper mine located in Pará State, Brazil. The Company also owns 97.6% of NX Gold S.A. which owns the Xavantina Operations, an operating gold and silver mine located in Mato Grosso State, Brazil. In July 2024, the Company signed a definitive earn-in agreement with Vale Base Metals for a 60% interest in the Furnas Copper-Gold Project, located in the Carajás Mineral Province in Pará State, Brazil. For more information on the earn-in agreement, please see the Company’s press releases dated October 30, 2023 and July 22, 2024. Additional information on the Company and its operations, including technical reports on the Caraíba Operations, Xavantina Operations, Tucumã Operation and the Furnas Copper-Gold Project, can be found on the Company’s website (www.erocopper.com), on SEDAR+ (www.sedarplus.ca/landingpage/) and on EDGAR (www.sec.gov). The Company’s shares are publicly traded on the Toronto Stock Exchange and the New York Stock Exchange under the symbol “ERO”.