y/ TSX: ERO “NYSE: ERO
June 10, 2026
Ero Confirms High-Grade Continuity and Extends Known Mineralization at Furnas with
Significant New Step-Out Intercepts
Vancouver, British Columbia — Ero Copper Corp. (TSX: ERO, NYSE: ERO) ("Ero" or the “Company”) is pleased to announce assay results on an additional 24,000 meters of exploration drilling performed subsequent to the Phase 1 program at the Furnas Copper- Gold Project ("Furnas" or the "Project"), located in the Carajas Mineral Province in Para State, Brazil. The Company has completed over 75,000 meters of drilling through the end of May 2026, with assay results currently available for approximately 52,000 meters. There are ten drill rigs operating at the Project, and the deposit remains open to depth and along strike.
Assay results from the ongoing drill programs are highlighted by significant step-out drill results occurring along strike and to depth:
FURN-DD-00357: 90 meters at 0.74% copper, 0.50 grams per tonne ("gpt") gold and 3.18 gpt silver (1.13% CuEq}), including 32 meters at 1.17% copper, 0.68 gpt gold and 5.40 gpt silver (1.70% CuEq’), a step-out hole in the SE zone, extending the known limits of mineralization by approximately 115 meters down-dip, demonstrating potential for additional high-grade extensions within the SE zone.
FURN-DD-00354: 45 meters at 0.98% copper, 0.36 gpt gold and 1.72 gpt silver (1.25% CuEq}), including 20 meters at 1.78% copper, 0.25 gpt gold and 3.12 gpt silver (1.98% CuEq!'), representing a high-grade step-out intercept in the SE zone approximately 80 meters beyond the limit of the inferred mineral resource.
FURN-DD-00368: 41 meters at 0.94% copper, 0.44 gpt gold and 1.58 gpt silver (1.28% CuEq?), including 16 meters at 0.87% copper, 0.89 gpt gold and 1.52 gpt silver (1.53% CuEq?), drilled in the Central zone of the Project, approximately 220 meters down-dip of the inferred mineral resource estimate and more than 1.1 kilometers west of the high-grade resource of the SE zone, highlighting a new zone of exploration potential between the established SE and NW zones.
And by high-grade infill results within the primary SE and NW mineralized zones:
FURN-DD-00340: 88 meters at 0.81% copper, 0.61 gpt gold and 3.75 gpt silver (1.29% CuEq}), including 27 meters at 1.25% copper, 0.77 gpt gold and 6.06 gpt silver (1.86% CuEq'), demonstrating high-grade continuity over significant thicknesses within the SE zone, supporting the ongoing resource conversion drill program.
FURN-DD-00348: 65 meters at 0.65% copper, 0.42 gpt gold and 1.30 gpt silver (0.97% CuEq}), including 26 meters at 0.78% copper, 0.42 gpt gold and 1.30 gpt silver (1.18% CuEq') and 12 meters at 0.67% copper, 0.65 gpt gold and 2.12 gpt silver (1.60% CuEgq?), drilled at the northwestern edge of the NW zone mineral resource, supporting future resource growth potential. The hole also returned a shallower intercept of 15 meters at 2.97% copper and 11.81 gpt silver (3.05% CuEq’).
Ero
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TSX: ERO
NYSE: ERO
WORK PROGRAM HIGHLIGHTS
Drilling continues to demonstrate high-grade continuity within the NW and SE zones and extend mineralization both to depth and strike adjacent to planned underground infrastructure of the Preliminary Economic Assessment ("PEA")? mine plan. The most recent set of assay results include approximately 6,000 meters of infill drilling targeting conversion of inferred mineral resources to at least indicated mineral resources in support of future engineering studies.
The Company remains on track to complete the three contractual drilling programs under the Furnas earn-in agreement by year-end, approximately 2 years ahead of the required schedule for the drilling milestones. Pursuant to the agreement, the Company will earn a 60% interest in the Project upon completion of these drill programs and prescribed engineering work programs.?
In parallel, the Company is well-advanced across additional technical work streams including permitting, confirmatory metallurgical testwork, advanced geotechnical drilling, hydrogeological studies and ongoing environmental baseline studies in support of a Pre-Feasibility Study ("PFS") expected to be published in 2027.
The Company expects to award the engineering contract for the PFS and Feasibility Study ("FS") in mid-2026.
In addition, value-enhancement opportunities identified in the PEA continue to be evaluated, including magnetic separation of tailings to produce a high-grade magnetite (iron) concentrate and a gravity circuit to improve gold recoveries.
"Every drill result from Furnas reinforces the scale, quality and growth potential of the deposit," said Makko DeFilippo, President and Chief Executive Officer. "High-grade continuity within the SE and NW zones remains strong, and new step-out drilling in the Central zone, near planned infrastructure, highlights new opportunities to build upon an already compelling PEA mine plan.
"We are advancing Furnas on multiple fronts, with ten drill rigs operating on site and permitting, engineering and environmental workstreams progressing toward a PFS. Together with Vale Base Metals*, we remain focused on de-risking the Project and positioning Furnas as a cornerstone of Ero’s long-term organic growth strategy."
1.
Where applicable, copper equivalent ("CuEq") in this press release has been calculated using the following formula: Cu grade + ((Au grade x 0.03215 x US$2,500 gold price x 74.6% gold metallurgical recovery) + (Ag grade x 0.03215 x US$24.00 silver price x 71.0% silver metallurgical recovery)) / (0.01 x US$9,038.94/tonne copper price x 90.3% copper metallurgical recovery).
For more information on the updated Furnas mineral resource estimate and inaugural PEA, please see the Company's press release dated February 23, 2026 and the 2026 Technical Report (as defined below).
For more information on the Company's plans to earn a 60% interest in the Furnas Copper-Gold Project, please see its press releases dated October 30, 2023 and July 22, 2024.
"Vale Base Metals" includes Vale Base Metals Limited and its subsidiaries.
Ero
625 Howe Street | Suite 1050 | Vancouver | BC | V6C 2T6 | Canada
TSX: ERO
NYSE: ERO
Environmental Studies in Support of Project Permitting Advancing
Baseline environmental studies commenced in Q1 2024, building on historical environmental work conducted by Vale Base Metals ("VBM"). The Company plans to submit an application for a Preliminary License by year-end 2026, following the expected completion of an Environmental Impact Assessment and Environmental Impact Report ("EIA/RIMA"). Mining projects in Brazil require a three-phase licensing process, in parallel with the federal miningtitle process administered by the National Mining Agency:
e Phase 1 - Preliminary License: Confirms environmental feasibility and approves the Project’s location and basic design concept, following review of the EIA/RIMA and applicable public consultation requirements.
e Phase 2 - Installation License: Authorizes construction and installation in accordance with approved engineering plans and environmental control programs, subject to compliance with Preliminary License conditions.
e Phase 3 - Operating License: Authorizes operations after construction is complete, required environmental controls are implemented and applicable environmental, mining and other regulatory conditions have been satisfied.
Key environmental authorizations secured to date at Furnas include vegetation clearance, wildlife management, a water use permit for exploration and additional water-take authorization.
Metallurgical Testwork Continues to Validate PEA Assumptions; Moving Forward with Evaluation of Value-Enhancement Opportunities
Metallurgical testwork completed since the publication of the PEA includes seven additional variability tests, 24 additional locked-cycle flotation tests, and a continuous mini pilot plant test. Results continue to support the proposed metallurgical process flowsheet outlined in the PEA and validate recoveries for copper, gold and silver as well as concentrate quality parameters. Additional pilot plant variability tests will be performed in H2 2026 in support of the PFS.
Additional testwork continues to show that magnetic separation of flotation tailings offers the potential to produce a high-grade magnetite concentrate while also reducing tailings mass, representing a significant value-enhancement opportunity for the Project in future studies.
Drill Results Continue to Demonstrate High-Grade Continuity and Extend Mineralization
Drill results in this update include approximately 24,000 meters of drilling comprised of 6,000 meters of infill drilling and approximately 18,000 meters of resource extension drilling. Infill drilling was designed to target upgrades of inferred mineral resources to higherconfidence categories, while resource expansion drilling focused on demonstrating extensions at depth and along strike, including opportunities within the under-explored Central zone between the well established NW and SE mineralized corridors.
3 Ero 625 Howe Street | Suite 1050 | Vancouver | BC | V6C 2T6 | Canada
TSX: ERO
NYSE: ERO
ABOUT THE FURNAS COPPER-GOLD PROJECT
Furnas is an iron oxide copper-gold deposit located approximately 70 kilometers southeast of Vale Base Metal's Salobo Operations and approximately 190 kilometers northeast of Ero's Tucuma Operation. Covering an area of approximately 2,400 hectares, the Project sits within fifteen kilometers of extensive regional infrastructure, including paved roads, an industrialscale cement plant, a power substation and Vale S.A.'s railroad loadout facility.
In July 2024, the Company signed a definitive earn-in agreement ("Agreement") with Salobo Metais S.A.°, to earn a 60% interest in the Project upon completion of several exploration, engineering and development milestones over a five-year period. In exchange for its 60% interest, Ero will solely fund a phased work program during the earn-in period and grant VBM up to an 11.0% "free carry" on future Project construction capital expenditures. For additional details on the key terms and execution of the Agreement, please refer to the Company's press
releases dated October 30, 2023 and July 22, 2024.
The Company published a PEA on the Project on March 30, 2026 with an effective date of February 23, 2026, highlighting an initial 24-year mine life with LOM average annual production of 81 kt CuEq with average annual production of 108 kt CuEq? over the first 15 years of mine life. The PEA is supported by an updated mineral resource estimate, with an effective date of November 30, 2025, that incorporates approximately 90,000 meters of historical drilling completed by Vale S.A. and Anglo American plc, together with 28,000 meters of Phase 1 drilling completed by the Company through July 2025.
For additional information on the PEA and the Project's mineral resource estimate, please see the Company's press release dated February 23, 2026 as well as the corresponding technical report titled “Preliminary Economic Assessment for the Furnas Project — Para State, Brazil — NI 43-101 Technical Report”, dated March 30, 2026 with an effective date of February 23, 2026 (the "2026 Technical Report"), which is available under the Company's profile on SEDAR+ (www.sedarplus.com), on EDGAR (www.sec.gov) and on the Company's website (www.ero.com).
The PEA is preliminary in nature and includes inferred mineral resources, which are considered too speculative geologically to have the economic considerations applied to them that would enable them to be categorized as mineral reserves, and there is no certainty that the PEA will be realized. Mineral resources that are not mineral reserves do not have demonstrated economic viability.
- 1. Where applicable, copper equivalent ("CuEq") in this press release has been calculated using the following formula: Cu grade + ((Au grade x 0.03215 x US$2,500 gold price x 74.6% gold metallurgical recovery) + (Ag grade x 0.03215 x US$24.00 silver price x 71.0% silver metallurgical recovery)) / (0.01 x US$9,038.94/tonne copper price x 90.3% copper metallurgical recovery).
- 5. Salobo Metais S.A., is a wholly owned subsidiary of Vale Base Metals Limited. Vale Base Metals Limited is 90% indirectly owned by Vale, and 10% indirectly owned by Manara Minerals Investment Company (Manara Minerals).
4 Ero 625 Howe Street | Suite 1050 | Vancouver | BC | V6C 2T6 | Canada
TSX: ERO
NYSE: ERO
Lithology
-HCS GRA |) bio RCL HD _GMFHD |) GMF HD-2
xa RSL Host _GMF RSL
Legend e Ero - PEA (Phase 1) e Ero - New Drillholes e Vale - Historical
. o 0 1,000 2,000
e News Release Highlights —— Ee Projection UTM
Zone 22S
Figure 1: Furnas Geology Plan View Map, including drill collar locations. Rock types include:
Abbreviation Rock Type
HCS Calcic-sodic hydrothermal rock
GRA Granite
DIO Diorite
RCL HD Chlorite-rich hydrothermal rock
GMF HD Grunerite-garnet-magnetite hydrothermal rock
GMF HD-2 Grunerite-garnet-magnetite hydrothermal rock
XTA Aluminous schist
RSL Host Quartz-rich rock
GMF RSL Magnetite-rich hydrothermally altered rock / Quartz-rich rock 5 Ero
625 Howe Street | Suite 1050 | Vancouver | BC | V6C 2T6 | Canada