ERO.TO · 2018-09-05 12:00:00

Ero Copper announces more than 100% increase in mineral reserves and resources at the Vale do Curaçá Property

Resource Estimates

TSX: ERO

Ero Copper Corp

SEPTEMBER 5, 2018 NR:18-11

Ero Copper announces more than 100% increase in mineral reserves and resources at the Vale

do Curaçá Property

Vancouver, British Columbia – Ero Copper Corp. (the “Company”) (TSX: ERO) is pleased to

announce the release of its 2018 updated mineral reserve and resource estimate along with updated

production, capital and operating cost projections for its 99.6% owned Vale do Curaçá Property

located in Bahia State, Brazil. Highlights of the 2018 mineral reserve and resource estimate

include:

• A 108% increase in Proven and Probable mineral reserves to over 18 million tonnes (with

a 55% increase in contained copper) compared to the Proven and Probable mineral reserves

set out in the 2017 Technical Report (as defined below), using the same copper price and

foreign exchange assumptions of $2.75/lb and USD:BRL of 3.20, respectively;

• A 107% increase in Measured and Indicated mineral resources to over 42 million tonnes

(with a 57% increase in contained copper), inclusive of mineral reserves, as compared to

the Measured and Indicated mineral resources set out in the 2017 Technical Report at the

same geological cut-off grades;

• An updated production plan increasing the life of the mine by adding approximately

124,000 tonnes of copper production as compared to the life of mine production plan set

out in the 2017 Technical Report; and

• The updated plan will produce, on average, approxi mately 41,000 tonnes of copper in

concentrate over the first five years at an average C1 cash cost of $0.94/lb.

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Ero Copper Corp

The 2018 updated mineral reserve and resource estimate is shown in the table below:

Classification Tonnage

(000 tonnes)

Grade

(Cu %)

Cu Contained

(000 tonnes)

Reserves

Proven 13,591 1.90 258.8

Probable 4,846 1.73 84.0

Total Proven & Probable 18,437 1.86 342.8

M&I Resources (including Reserves)

Measured 28,506 1.76 501.8

Indicated 13,921 1.60 222.6

Total Measured & Indicated 42,428 1.71 724.4

Inferred 6,328 1.29 81.4

Mineral Reserve & Resource Notes:

1. Mineral reserve effective date of August 1, 2018.

2. Mineral resource effective date of July 1, 2018 for the Pilar and Surubim m ines, and May 31, 2018 for the

Vermelhos mine, Vermelhos West and R22W.

3. Presented mineral resources inclusive of m ineral reserves. All figures have been rounded to the relative

accuracy of the estimates. Summed amounts may not add due to rounding.

4. Mineral resource copper cut-off grades of 0.68% copper for underground mineral resources and 0.18% for

open pit mineral resources. Mineral resources have been estimated using ordinary kriging inside 5m by 5m

by 5m block sizes. The mineral resource 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

23, 2003 (the ‘CIM Guidelines”), using geostatistical and/or classical methods, plus economic and mining

parameters appropriate to the deposit. Effective date of the mineral resource estimate varies by deposit. Please

see “Technical and Scientific Information” near the end of t his news release for additional information on

the stated mineral resources.

5. 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 r eserves are based on a long -term copper price of US$2.75 per pound (“lb”), and a

USD:BRL foreign exchange rate of 3.20. Mineral reserves are the economic portion of the Measured and

Indicated mineral resources. Mineral reserve estimates include mining dilution at zero grade. Mining dilution

and recovery factors vary for specific mineral reserve sources and are influenced by factors such as deposit

type, deposit shape, stope orientation and selected mining method. Please see “Technical and Scientific

Information” near the end of this news release for additional information on the stated mineral reserves.

Mineral resources which are not mineral reserves do not have demonstrated economic viability.

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Ero Copper Corp

UPDATED PRODUCTION PLAN

The Company’s updated production plan, prepared in conjunction with the mineral resource and

mineral reserve update, provides a solid platform from which to grow copper production, improve

operating efficiencies, and reduce capital and operating costs in the future as new deposits are

discovered and developed within the Curaçá Valley. The new mine plan, with stabilized mill feed

and copper grades, provides greater flexibility to better utilize the Caraíba Mill’s installed capacity

of 3.2 million tonnes per annum, as well as continue to evaluate expansion opportunities to return

the mill to its original installed capacity of 5.5 million tonnes per annum.

The table below outlines the updated production plan for the Vale do Curaçá Property. The plan is

centered upon providing the Caraíba Mill with a more consistent plant feed averaging 2.1 million

tonnes producing, on average, approximately 41,000 tonnes of copper in concentrate per annum

over the next five years.

2017A

2018

Guidance* 2019e 2020e 2021e 2022e 2023e 2024e 2025e 2026e

Ore Processed

(000 tonnes) 1,771 ~2,000 1,867 1,883 2,146 2,184 2,172 2,909 3,017 1,453

Copper Grade

(% Cu) 1.31% 1.50% 2.24% 2.34% 2.58% 2.13% 2.10% 1.21% 1.20% 1.18%

Copper in

Concentrate

(000 tonnes)

20.1 25.5 - 27.5 37.1 39.2 48.6 40.6 40.1 30.1 30.8 14.8

*Please refer to the Company’s news release dated January 9, 2018 for complete guidance information.

UPDATED OPERATING & CAPITAL COSTS

The updated production plan has resulted in change s to the forecast operating and capital cost

estimates. The tables below show the operating and capital costs for the updated production

schedule.

TSX: ERO

Ero Copper Corp

2017A

2018

Guidance 2019e 2020e 2021e 2022e 2023e 2024e 2025e 2026e

C1 Cash Cost

(US$/lb. Cu) 1.54 1.30 – 1.40 0.96 1.02 0.81 0.99 0.96 1.65 1.42 1.43

C1 Cash Cost Notes:

1. Assumes USD:BRL FX rate of 3.80 in years 2019 through 2026.

2. Assumes gold price of US$1,250 per ounce and silver price of US$17.50 per ounce.

3. C1 Cash Cost of copper produced is a non- IFRS measure – refer to “Technical and Scientific Information”

near the end of this news release for additional detail.

4. Starting in 2018, the Company included costs of treatment, refining and sales costs and credits related to the

sale of copper concentrate in its C1 Cash Cost calculation. These adjustments were not included in the 2017

Technical Report.

5. Please refer to the Company’s news release dated January 9, 2018 for complete guidance information.

2017A

2018

Guidance 2019e 2020e 2021e 2022e 2023e 2024e 2025e 2026e

Capital

Expenditures

(US$M)

n/a 95.0 59.0 33.6 20.3 12.9 17.6 10.0 0.8 0.1

Capital Expenditure Notes:

1. Assumes USD:BRL FX rate of 3.80 in years 2019 through 2026.

2. Please refer to the Company’s news release dated January 9, 2018 for complete guidance information.

3. Capital expenditures shown do not include discretionary greenfield or brownfield exploration in years 2019

to 2026.

MINERAL RESOURCE & RESERVE GROWTH

The following section discusses the updated mineral reserve and resource estimates as they relate

to each of the three mineral districts of the Vale d o Curaçá Property. Detailed information with

respect to tonnes, grade and contained copper for the mineral reserve and resource estimates for

each mineral district can be found at the end of this news release. Relative comparisons to 2017

refer to the 2017 Technical Report.

Pilar

The amount of contained copper within the Measured and Indicated mineral r esources increased

by 40% in the Pilar mine. This increase in contained copper was primarily attributable to increases

in the Deepening Zone (228 thousand tonnes (“kt”) contained copper in 2017 vs. 287kt contained

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Ero Copper Corp

copper in 2018), new resources from the north extension zone (increase of 15kt contained copper)

and a portion of the West Limb defined by historical drilling (increase of 61kt contained copper).

Infill and extensional drilling at the Pilar mine resulted in a 60% increase in the amount of copper

within the Proven and Probable mineral reserve estimate . The newly identified West Limb

contributed an increase of 44kt of contained copper to the mineral reserves, while infill and

extension drilling in the Deepening, South Extension, and P1P2NE zones collectively contributed

an additional 27kt of contained copper (see Figure 1 for additional detail on resource areas of the

Pilar mine). No material change occurred in the Proven and Probable mineral reserve estimate in

the Deepening Zone.

During the upcoming year, infill drilling will focus on converting newly identified mineral

resources to reserves, particularly within the Deepening Zone and West Limb, while the

exploration program will continue to expand mineral resources within the West Limb and downdip

extensions to the Deepening Zone.

Vermelhos

Contained copper within the Measured and Indicated mineral resource estimate increased by 68%

at Vermelhos. This increase is attributable to a new area of mineral resource (“Vermelhos West”),

which was defined by historic drilling but only recently re-evaluated (increase of 49kt of contained

copper), along with expansions of the UG1 and UG2 mining areas defined as part of the Vermelhos

infill drill program. Increases in the main portion of the Vermelhos underground mine , including

UG1 and UG2 mining areas, totaled 34kt of contained copper within the Measured and Indicated

mineral resources (see Figure 2 for additional detail on resource areas of the Vermelhos Mine).

Vermelhos West is a zone of mineralization located approximately 1 kilometer to the north, north-

east of, and on trend with, the Vermelhos mine. The M easured and I ndicated mineral resources

extend from near-surface to a depth of approximately 200 meters, the depth of the historic drill

program. The deposit remains open at depth, and a dditional work is plan ned to determine the

relationship between mineralization in this zone and that of the main orebodies of the Vermelhos

mine.

Infill and extension drilling within the main Vermelhos mine resulted in a 24% increase in the

Proven and Probable mineral reserves (100kt of contained copper in 2017 vs. 125kt of contained

copper in 2018). In addition, 8kt of contained copper was added to the Proven and Probable mineral

reserves from the Vermelhos West.

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Ero Copper Corp

During the upcoming year, drilling at the Vermelhos m ine, and Vermelhos West, will focus on

converting mineral resources to reserves while continuing to test extensions of known mineral

resources and evaluating new targets to depth.

Surubim

Contained copper within t he Measured and Indicated mineral resource estimate at the Surubim

mine increased by 1,208% (4kt of contained copper in 2017 vs. 47kt of contained copper in 2018).

The increase in contained copper is attributable to expansion of resources being mined within the

current operating open pit along with extensions below the pit , as well as satellite zones defined

adjacent to the mine (see Figure 3 for additional detail on resource areas of the Surubim mine).

In conjunction with the increase in contained copper within the Measured and Indicated mineral

resources, there was an 885% increase in the contained copper within the Proven and Probable

mineral reserves at the Surubim mine (2kt of contained copper in 2017 vs. 20kt of contained copper

in 2018). The increase in Proven and Probable mineral reserves was attributable primarily to

downdip extensions of the reserves currently being mined from the Surubim open pit mine. These

downdip extensions will be mined in the future via a decline to be developed from the bottom of

the current open pit.

During the course of the next year, drilling will focus on continuing to define underground

extensions to mineralization along with further defining mineral resources in satellite zones

adjacent to, and on trend with, the open pit mine.

REGIONAL EXPLORATION PROGRAM UPDATE

The Company’s airborne geophysical survey comprised of both electromagnetic and gravity

systems has now been completed over the planned survey area. Data processing is nearing

completion and prioritization of initial drill targets is currently underway.

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Ero Copper Corp

TECHNICAL AND SCIENTIFIC INFORMATION

Mineral Resources

Block model tonnage and grade estimates for the Vale do Curaçá Property were classified

according to the CIM Standards and the CIM Guidelines by Sr. Porfirio Cabaleiro Rodriguez with

contributions by Fabio Valerio Xavier and Bernardo Viana, all of GE21 Consultoria Mineral Ltda.

All are independent Qualified Persons as such term is defined in N ational Instrument 43- 101,

Standards of Disclosure for Mineral Projects (“NI 43-101”).

Cut-off grades of 0.68% copper were used for underground mineral resources and 0.18% for open

pit mineral resources. Mineral resources were estimated using ordinary kriging within 5m by 5m

by 5m block sizes. Mineral resources are shown inclusive of mineral reserv es. Effective date of

July 1, 2018 for the Pilar and Surubim mines, and May 31, 2018 for the Vermelhos mine,

Vermelhos West and R22W.

Mineral Reserves

The Mineral reserves for the Pilar, Vermelhos, and Surubim mines and Surubim Underground are

derived from the Measured and Indicated mineral resources as defined within the resource block

models following the application of economic and other modifying factors further described

below. Inferred mineral resources, where unavoidably included within a defined mining shape

have been assigned zero grade.

Mineral reserves were classified according to the CIM Standards and the CIM Guidelines by

Rubens Mendonça of Planminas – Projectos e Consultoria em Mineração Ltd., an independent

Qualified Person as such term is defined in NI 43-101.

Mineral Reserve Estimate Parameters:

Mining Costs (US$/tonne ore mined)

Pilar UG mine $31.78

Vermelhos UG mine $26.52

Surubim OP mine $3.71

Surubim UG $13.95

Vermelhos West $3.71

R22W OP $3.67

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Ero Copper Corp

Transportation Costs (US$/tonne to mill)

Vermelhos mine $6.63

Surubim mine $5.98

Processing Costs (US$/tonne milled) $8.83

Metallurgical Recovery (average)* 86.90%

LME Copper Price (US$/lb) $2.75

Net Smelter Return 94.53%

Foreign Exchange Rate (USD:BRL) 3.20

*Metallurgical recoveries vary by area. Estimated metallurgical recoveries of 86.0% used for Pilar UG Mine, 90.0%

for Vermelhos UG Mine, 70.0% for R22W OP, 83.0% for Vermelhos West, 85.0% for Surubim UG and 80.0% for

Surubim OP Mine.

Other modifying factors considered in the determination of the mineral reserve estimate include:

• Maximum bench height of 10m for open pit mines. Maximum underground stope

dimensions based on geotechnical assessments from previous studies and past operating

experience within each mining area, combined with evaluation of induced stresses and the

Rock Mass Rating (“RMR”).

• The Vertical Retreat Mining (“ VRM”) method with cemented paste fill was selected for

the Pilar UG Mine, where the method is currently in use. For the Vermelhos UG Mine,

Sublevel Open Stoping method ( “SOS”) was chosen as the mining method after

consideration of the dip, plunge and thickness of the ore -bodies, the rock quality

designation (“RQD”) and overall competence of the host rock. Variations of this method

are planned for the central high -grade area for the maximum possible recovery via

cemented rockfill matrix filling (“CRF”).

• Within d esigned stopes, all contained material was assumed to be mined with no

selectivity. Inferred mineral resources, where unavoidably included within a defined

mining shape have been included in the mineral reserves estimate at zero grade.

• Dilution and mining recovery values vary by deposit as set forth below:

- Pilar UG mine operational dilution of 10%, mining recovery of 96%

- Vermelhos UG mine operational dilution of 20%, mining recovery of 100%

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