Ero Copper Corp. (TSX: ERO) (NYSE: ERO) is pleased to announce the discovery of a regional nickel sulphide system within the Curaçá Valley over an initial strike length of five kilometers. The system remains open in all directions and is highlighted by multiple surface expressions of nickel mineralization. Results from first-pass drilling conducted on two of the identified zones along the currently interpreted northeast and southwest boundaries of the system are highlighted by:

• VB Zone
  • VB-17: 16.5 meters at 1.22% Ni, 0.17% Cu and 0.03% Co (1.37% NiEq), including 3.8 meters at 3.60% Ni, 0.22% Cu and 0.09% Co (3.92% NiEq)
    • Interval includes 1.5 meters of massive-sulphide textures (~80% sulphides) grading 6.59% Ni, 0.26% Cu and 0.17% Co (7.11% NiEq)
  • VB-25: 30.4 meters at 0.63% Ni, 0.12% Cu, 0.02% Co (0.72% NiEq), including 5.1 meters at 2.06% Ni, 0.25% Cu, 0.05% Co (2.28% NiEq)
    • Interval includes 1.4 meters of massive-sulphide textures (~60% sulphides) grading 4.94% Ni, 0.14% Cu, 0.12% Co (5.30% NiEq)
• Lazaro (“LZ”) Zone
  • LZ-03: 24.1 meters at 0.81% Ni, 0.18% Cu and 0.04% Co (0.97% NiEq), including 13.0 meters at 1.11% Ni, 0.25% Cu and 0.05% Co (1.33% NiEq)
  • LZ-06: 22.5 meters at 0.84% Ni, 0.15% Cu and 0.05% Co (1.02% NiEq), including 8.0 meters at 1.34% Ni, 0.25% Cu and 0.07% Co (1.61% NiEq)
  • LZ-07: 17.7 meters at 0.93% Ni, 0.21% Cu and 0.05% Co (1.14% NiEq), including 5.0 meters at 1.15% Ni, 0.20% Cu and 0.06% Co (1.38% NiEq)

The newly discovered nickel system, known as the “Umburana System”, is located approximately 20 kilometers from the Company’s existing Caraíba processing facilities. The system was discovered using new detailed field mapping and soil geochemistry collected during the Company’s 2021 and 2022 exploration programs in conjunction with the Company’s airborne electromagnetic (“AEM”) survey. First-pass drilling comprised of 48 drill holes initially testing where ultramafic rocks have been mapped at surface. The ongoing program has identified large intervals of disseminated and interstitial nickel sulphides as well as zones of high-grade semi-massive (containing approximately 30% to 60% sulphides) and massive sulphides (containing approximately 60% to 80% sulphides), with massive sulphide intercepts up to 1.5 meters in thickness grading up to 6.59% nickel (7.11% NiEq). Nickel mineralization outcrops at surface, is evident in trenches and remains open down-plunge. Maximum depth of drilling to date is approximately 300 meters below surface. There are four exploration drill rigs currently operating on the system.

Commenting on the discovery, David Strang, Chief Executive Officer, said “This is a significant and pivotal moment for the Company and, more broadly, for the region. To think that copper in the Curaçá Valley was first documented in the late 1700s and we are just now discovering nickel sulphide mineralization not far from where copper has been mined for over 40 years is truly remarkable. As a Company, we have been working to better understand the potential for nickel occurrences since first observed within the Vermelhos Mine in 2018. With newly compiled datasets, dedicated resources focused exclusively on understanding and finding nickel and a complete re-look of several historic datasets this past year, our efforts and persistence have paid off. We believe today’s results confirm the Curaçá Valley’s potential to be a globally significant magmatic sulphide district for both copper and nickel.”

Mike Richard, the Company’s Chief Geological Officer, added “From my perspective, this is the most significant development in the Curaçá Valley’s regional exploration program to date. I am incredibly proud of our exploration team for their contributions to making our first nickel discovery and believe we are at the early stages of unlocking significant value for the Company. These zones are the first targets we have drill tested in what is an emerging new exploration frontier, and based upon results to date, we have good geological evidence to support the “key” signatures for nickel potential that we expect will vastly enhance our nickel exploration program in the months and years ahead.”

TECHNICAL DISCUSSION

The first significant documented occurrence of nickel sulphides in the Curaçá Valley was made by the Company during the Vermelhos Mine development, and later in discrete zones of copper-nickel massive sulphides within the Siriema Deposit in late 2018 and 2019, respectively. Detailed geologic mapping, comprehensive multi-element soil geochemistry and re-interpretation of the Company’s available geophysical datasets throughout 2021 and the first-half of 2022 has resulted in the discovery of a new nickel system featuring favourable geology with coincident geochemical and geophysical anomalies. To date, detailed exploration has focused on two target areas located at the interpreted northeast and southwest boundary of a five-kilometer system each characterized by multiple expressions of outcropping nickel mineralization in the form of gossans, geochemical and geophysical anomalies – all associated with mafic-ultramafic intrusions. Please refer to Figure 3 for a plan view map of the Umburana System.

Initial drill-testing at the northeast and southwest boundaries of the currently known system has identified nickel sulphide mineralization ranging from disseminated and interstitial nickel sulphides (containing less than 10% sulphides) extending over 50 meters in thickness to patchy net-textured sulphides (containing approximately 10% to 30% sulphides) with localized centimeter up to 1.5 meter thick massive-sulphide lenses (containing approximately 60% to 80% sulphides) grading up to 6.59% nickel (7.11% NiEq). Mineralization within these zones is hosted by pyroxenite and peridotite ultramafic rocks. Sulphide minerals are mainly pyrrhotite, pentlandite (loop-textured where massive sulphide, see Figure 1) with lesser pyrite and chalcopyrite. Loop-textured pentlandite is an important geologic indicator commonly observed in magmatic nickel sulphide deposits. The full extent of the system is unknown at this time. Mineralization remains open down-dip and along strike. Exploration work remains ongoing.

No metallurgical testwork has been completed to date. Metallurgical samples from select drillhole composites within the Umburana System are currently being collected for preliminary testwork including detailed mineralogy as well as laboratory flotation tests. Where applicable, nickel equivalent (“NiEq”) in this press release has been calculated using the following formula: NiEq = Ni + (Cu x $3.50/$9.80) + (Co x $25.50/$9.80). No adjustment for metallurgical recoveries has been made when calculating NiEq.

VB Zone

At the northeast extent of the Umburana System nickel-bearing ultramafic rocks have been identified over 1.4 kilometers north-south and up to 200 meters east-west using surface mapping supported by soil geochemistry and 20 trenches. To date, 24 holes with assay results have been received. Mineralization within the VB Zone is primarily comprised of disseminated, and patchy net-textured nickel sulphide mineralization with zones of high- grade massive sulphide mineralization featuring localized thickening of up to 1.5 meters grading up to 6.59% nickel (7.11% NiEq). Within the VB Zone, higher-grade mineralization appears to be focused at the base of a pyroxenite intrusion. Mineralization occurs predominantly within orthopyroxenites ranging from isotropic to locally banded.

Within the central high-grade portion of the VB Zone, results are highlighted by two holes, VB-05 and VB-17, both located on the same section, which intercepted high-grade massive sulphides of up to 1.5 meters grading up to 7.11% NiEq within broader mineralized intervals ranging between approximately 17 and 20 meters grading between 0.75% NiEq to 1.37% NiEq. Please see “VB Zone Intercepts” table below for complete results.

The deepest drilling to date within the VB Zone is highlighted by hole VB-25 that intercepted high-grade massive sulphide of up to 1.4 meters grading up to 5.30% NiEq, approximately 290 meters below surface. When combined with surface trenching and previously highlighted intercepts in hole VB-05 and hole VB-17, high-grade nickel sulphide mineralization can be traced from surface to over 300 meters down-dip. Additional exploration work to understand the relationship between these high-grade massive sulphide intercepts and other intercepts of high-grade nickel mineralization identified throughout the VB Zone remains ongoing.

There are currently three drill rigs active within the VB Zone. Please see Figures 4 and 5 for additional details on drill hole locations and intercepts.

VB Zone Intercepts

^{NSI denotes no significant intercept grading above 0.10% Ni. Drill holes were drilled from surface. Holes not included are either pending assay results or have been included in a different section of this press release. The length of intercept may not represent the true width of mineralization. Values may not add up due to rounding. From, To and Length are rounded to the nearest tenth of a meter.}

^{(*) denotes interval of massive sulphide within larger reported intercept.}

(a)

 (b)

Figure 1: Drill core from the deepest intercept to date in the VB Zone (hole VB-25 at ~319 meters) highlighting loop textured pentlandite in (a) and high-grade massive sulphide intervals within the zone (b).

LZ Zone

At the southwest extent of the Umburana System, located approximately 20 kilometers from the Company’s Caraíba milling operations and approximately 3.2 kilometers southwest of the VB Zone, nickel-bearing ultramafic rocks have been identified over 500 meters in strike- length and approximately 50 meters in apparent thickness using surface mapping supported by geochemistry, AEM response and eight trenches. To date, 24 holes with assay results have been received. Mineralization within the LZ Zone is primarily comprised of disseminated nickel sulphide mineralization with intercalated intervals of interstitial and net-textured sulphides (see Figure 2). Within the 500-meter identified strike length of the LZ Zone, a zone of higher- grade mineralization has been identified within the footwall of the mafic-ultramafic intrusion associated with a peridotite layer.

Results within the footwall of the LZ Zone are highlighted by two holes, LZ-03 and LZ-07, both located on the same section, which intercepted broad mineralized intervals between 18 and 24 meters grading between 0.97% NiEq to 1.14% NiEq. South along strike, hole LZ-06, drilled approximately 50 meters from holes LZ-03 and LZ-07, intercepted 22.5 meters grading 1.02% NiEq. When combined with surface trenching, higher-grade mineralization within the footwall of the LZ Zone can be traced from surface approximately 190 meters down-dip. Please see “LZ Zone Intercepts” table below for complete results.

The deepest drilling to date within the LZ Zone is highlighted by hole LZ-24 that intercepted broad mineralization over approximately 46 meters grading 0.27% NiEq from approximately 185 meters downhole. At the bottom of this broader mineralized intercept, an extension of the high-grade peridotite layer of the footwall zone, approximately 200 meters below surface, was intercepted over 5.7 meters grading 1.08% NiEq indicating the footwall zone remains open along strike to the north and to depth. Hole LZ-24 is located approximately 50 meters north of the higher-grade mineralization identified in the footwall highlighted by holes LZ-03 and LZ-07, and approximately 100 meters north of the footwall intercept in hole LZ-06. Exploration drilling to understand the relationship between these higher-grade intercepts remains ongoing, and there is currently 1 drill rig working within the LZ Zone. In parallel, exploration efforts at the LZ Zone continue to use systematic geological mapping, trenching, ground electromagnetic (“EM”) surveys and borehole EM surveys.

Please see Figure 6 and 7 for additional details on drill hole locations and intercepts.

LZ Zone Intercepts

^{NSI denotes no significant intercept grading above 0.10% Ni. Drill holes were drilled from surface. Holes not included are either pending assay results or have been included in a different section of this press release. The length of intercept may not represent the true width of mineralization. Values may not add up due to rounding. From, To and Length are rounded to the nearest tenth of a meter.}

(a)

 (b)

 (c)

Figure 2: Patchy net-textured sulphides shown in detail for hole LZ-03 (~107 meters) (a) showing both pentlandite and pyrrhotite (b) within broader interval (100.8 to 124.8 meters) showing 24.1 meters at 0.81% Ni, 0.18% Cu and 0.04% Co (0.97% NiEq), including 13.0 meters at 1.11% Ni, 0.25% Cu and 0.05% Co (1.33% NiEq) in (c).

NOTE ON NI 43-101 COMPLIANT TECHNICAL REPORT(S)

The conversion of drill results presented in this press release into NI 43-101 compliant mineral resources and mineral reserves all require additional work and analysis that remains ongoing. To date, there has been insufficient exploration and accompanying analysis to define a mineral resource and it is uncertain if further exploration will result in this nickel system being delineated as a mineral resource. Accordingly, the results herein may not be included in future NI 43-101 compliant mineral resources or mineral reserves depending on the results of this additional work and analysis, and other technical and/or economic reasons.

QUALITY ASSURANCE & QUALITY CONTROL

In support of its ongoing Umburana System exploration program, the Company is currently drilling on surface using third-party contracted core drill rigs. During the period from January 2022 through September 2022, third-party drill rigs were operated by Major Drilling do Brasil Ltda., and Layne Christensen Co. both of whom are independent of the Company. Drill core is logged, photographed and split in half using a diamond core saw at the secure core logging and storage facilities of Mineração Caraíba S.A. (“MCSA”). Half of the drill core is retained on site and the other half core is used for analysis, with samples collected on one- meter sample intervals unless an interval crosses a geological contact. All sample preparation is performed in MCSA’s secure on-site laboratory. Total nickel and copper is determined using a nitric-hydrochloric acid digestion and Atomic Absorption Spectrometry and/or Titration at the on-site laboratory. All sample results during the period have been monitored through a QA/QC program that includes the insertion of certified standards, blanks, and pulp and reject duplicate samples. Check-assays for nickel and copper were submitted to ALS Brasil Ltda’s facility located in Vespasiano, Minas Gerais, Brazil, at a rate of approximately 5%. ALS Brasil Ltda is a subsidiary of ALS Limited and is independent of the Company.

Emerson Ricardo Re, MSc, MBA, MAusIMM (CP) (No. 305892), Registered Member (No. 0138) (Chilean Mining Commission) of HCM Consultoria Geologica Eireli, who is a “qualified person” within the meanings of NI 43-101, has reviewed and approved the disclosure of technical information, including verification of the sampling, analytical and testing data in this press release. Quarterly reviews entail sampling and laboratory procedure review as well as verification of original assay certificates associated with a selection of samples from Company’s internal database included in this press release.

ABOUT ERO COPPER CORP

Ero Copper Corp is a high-margin, high-growth, clean 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, MCSA, 100% owner of the Company’s Caraíba Operations (formerly known as the MCSA Mining Complex), which are located in the Curaçá Valley, Bahia State, Brazil and include the Pilar and Vermelhos underground mines and the Surubim open pit mine, and the Tucumã Project (formerly known as Boa Esperança), an IOCG-type copper project located in Pará, Brazil. The Company also owns 97.6% of NX Gold S.A. which owns the Xavantina Operations (formerly known as the NX Gold Mine), namely comprised of an operating gold and silver mine located in Mato Grosso, Brazil. Additional information on the Company and its operations, including technical reports on the Caraíba Operations, Xavantina Operations and Tucumã Project, can be found on the Company’s website (www.erocopper.com), on SEDAR (www.sedar.com), and on EDGAR (www.sec.gov).