1COBRE DEL MAYO Investor PresentationDataasof1Q17

(all amounts in USD unless otherwise noted)

COBRE DEL MAYO 2

Disclaimer and Forward Looking StatementsThe information contained herein has been prepared to assist interested parties in making their own evaluation of the Company and does not purport to be all inclusive or to containall of the information that a prospective purchaser may desire.

Forward Looking StatementsThis Investor Presentation and other communication with investors include forward-looking statements. These forward- looking statements include, without limitation, statementsregarding our future financial position and results of operations, our strategy, plans, objectives, goals and targets, future developments in the markets in which we participate or areseeking to participate or anticipated regulatory changes in the markets in which we operate or intend to operate. In some cases, forward-looking statements can be identified byterminology such as “aim,” “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “forecast,” “guidance,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should” or“will” or the negative of such terms or other comparable terminology.

By their nature, forward-looking statements involve risks and uncertainties because they relate to events and depend on circumstances that may or may not occur in the future. Wecaution potential investors that forward-looking statements are not guarantees of future performance and are based on numerous assumptions and that our actual results ofoperations, financial condition and liquidity may differ materially from (and be more negative than) those made in, or suggested by, the forward-looking statements contained in thisInvestor Presentation. In addition, even if our results of operations, financial condition and liquidity and the development of the industry in which we operate, are consistent with theforward-looking statements contained in this Investor Presentation, those results or developments may not be indicative of results or developments in subsequent periods. Importantfactors that could cause these differences include, but are not limited to:

In light of these risks, uncertainties and assumptions, the forward-looking events described in this Investor Presentation may not occur. We undertake no obligation to update or reviseany forward-looking statement, whether as a result of new information or future events or developments.

• risks related to our liquidity;• risks related to the price of copper;• risks related to our competitive position;• risks related to our strategy and expectations about growth in demand for copper and

business operations, financial condition and results of operations;• risks related to our operations, including the quality of our ore body, our ability to

predict the nature, metallurgy, mineralization and alteration of the ore body and the effectiveness of our heap leaching process;

• risks relating to the operation by Kupari of its flotation plant; • risks related to the revocation, expropriation or termination of our mining concessions

or our water concessions or of the agreements pursuant to which we explore or exploit mining concessions belonging to third parties;

• the inability to be compensated fairly in the event of termination of our mining concessions or our water concessions;

• the impact of changes in the prices of raw materials, labor, services, sulfuric acid, components and other inputs;

• our relationship with unions and our ability to negotiate collective bargaining agreements;

• the availability of materials and equipment;• our access to funding sources, and the cost of the funding;• changes in regulatory, administrative or economic conditions affecting the mining

industry, including government interpretations and policies;• the application and enforcement of environmental laws and regulations;• risks related to Mexico’s social, political or economic environment;• the impact of changes in the end uses of our products;• fluctuations in the value of the U.S. dollar against the Mexican peso;• risks associated with market demand for and liquidity of the new notes; and• changes in the taxation of our business.

I. Cobre del Mayo

COBRE DEL MAYO 4

Cobre del Mayo Snapshot

Cobre del Mayo (“CDM”) is a Mexican mining company that mines the Piedras Verdes open-pit copper deposit (“Piedras Verdes mine”) located in Alamos, Sonora, México, it started operations in 2006

Piedras Verdes mine has an advantaged location, it is easily accessible by air, road, rail and ports. Given its location and nearby infrastructure, PV has competitive transportation costs for off-takers

CDM produces LME Grade A copper cathode and sells refractory and vein type ore for processing into copper concentrate to Kupari Metals

CDM owns 40% of Kupari Metals (“KM”), a Luxembourg mining company that operates a flotation circuit plant, adjacent to CDM

Piedras Verdes is the third largest copper mine in México and has reserves of 846 kt of copper contained in ore with a mine life of ~14 years

Low expected sustaining capex going forward of ~$11.6 M /yr LOM

COBRE DEL MAYO 5

Piedras Verdes Mine Site

§ 21 km from Alamos and 50 km from Navojoa

§ Air: 111 km (~90 min drive) from Ciudad Obregón internationalairport

§ Road: Connected by 14 km access road to paved highway

§ Rail: 50 km to the mainline north-south railway in Navojoa

§ Port: 250 km from the deep-water port of Guaymas

Piedras Verdes Mine

§ Highly skilled workforce and well-developed infrastructure

§ Power: Connected to CFE (Federal Electricity Commission) gridto the mine owned and maintained substation with continuouscapacity of 25 MW

§ Water: Holds 7 titled water concessions for ~3.9 Mm³/yr whilethe consuming is ~3.0 Mm³/yr

§ Strong social commitment and compliance with all applicableenvironmental standards

Mine Waste DumpMine Waste Dump

Mine Waste Dump

Heap LeachOperations

SX EW

Concentrator

MiningOperations

TSF

COBRE DEL MAYO 6

Piedras Verdes Mine Operations and Processes Diagram

Crushed Ore

Medium-grade oxides and supergene

leachable ores that are hauled to the ~30 ktpdprimary crusher. This ore is sent to leach

pads through a conveyor stacking system to minimize

compaction and costs

ROM

Run of Mine low-grade oxides and supergene leachable ores that are truck dumped, levelled, ripped and then leached

Chalcopyrite Ore

Low grade hypogeneore leached on

engineered pads with forced aeration

Ore for Concentrate Soldto Kupari

Highest grade sulphidicore is crushed, then sent to the Kupari

Metals flotation plant

§ Ore processing method is determined in accordance with grade, mineralization and leaching and flotation characteristics:

Primary Crusher

Fines Classifiction System Copper Cathodes

Leach Pads

COBRE DEL MAYO 7

Piedras Verdes Mine Processes Diagram

Cobre del Mayo isresponsible for mineoperations, includinggrade control andsequencing of heapleach pad materialplacement andcrushed feed to theflotation process

Kupari Metals is responsible foroperating the flotation plant, theflotation of slimes and thetailings storage facility

COBRE DEL MAYO 8

118.

9

100.

5

89.4

80.3

90.2

74.9

69.2

79.9

56.5

27.5

56.2

0

20

40

60

80

100

120

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

tpd

Copper (CuSeq) Chalcopyrite Copper (CuT)

71.5

63.8

51.4

44.0

47.3

51.2

47.7

54.2

57.6

129.

5

141.

1

161.

8

111.

8

123.

3

125.

0

144.

5

117.

8

121.

2

13.6

7.8 7.8

10.8

10.0

10.1

8.2

18.5

22.8

0

50

100

150

200

250

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

ktpd

Ore Mined Waste mined Re-handled

Re-handled of Chalcopyrite Ore to Leach Pads

Ore and Waste Mined & Re-handled Material (ktpd) Leachable Copper and Chalcopyrite to Leach Pads

Chalcopyrite

§ Since late 4Q16, the Company has leached chalcopyrite ore using an engineered leach pad with aeration

§ ~1 – 2 Mt lower grade chalcopyrite are mined per year. In the absence of a viable process, they were previously classified as waste

§ At the inception of this project ~6 Mt of lower grade chalcopyrite ore were available in stocks, most of which has been placed under leach

§ During 1Q17, re-handled material averaged 22.8 ktpd vs. 10.0 ktpd in 1Q16, of which 13.3 ktpd were associated with re-handling chalcopyritestocks sent to leach pads

COBRE DEL MAYO 9

70.2 75.0 65.3 56.5 55.4 58.6 50.8 56.9 61.9

38.0 33.131.5 44.1 37.7 33.2

29.9 31.4 22.2

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q170

30

60

90

120

tpd

Cathode Production Copper Contained in Ore Sold

Financial Highlights

Total CDM Sales ($ M) & Quarterly Realized Copper Price ($/lb)

Quarterly CDM C1 Cash Cost vs. Realized Copper Price

Cathode Production & Copper Contained in Ore Sold (tpd)

$46.5 $49.0 $31.7 $26.8 $26.5 $27.3 $25.0 $29.5 $36.2

$3.39$2.84

$2.28 $2.12 $2.11 $2.10 $2.16 $2.44 $2.65

$0

$20

$40

$60

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17$0.00

$1.00

$2.00

$3.00

$4.00

$ M

$/lb

Total CDM Sales ($M) Cu Price ($/lb)

$2.40 $2.40

$2.69$2.24 $2.11 $2.20

$2.71

$2.35 $2.33

$3.39$2.84

$2.28 $2.12 $2.11 $2.10 $2.16

$2.44 $2.65

$0.00

$1.00

$2.00

$3.00

$4.00

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$/lb

C1 Cash Cost ($/lb) Cu Price ($/lb)

COBRE DEL MAYO 10

1Q 2017 Financial Results

Financial Overview

§ Cu Cathode Hedge (March 28, 2017): CDM entered into an agreement for the sale of850 t of copper cathode per month from April to December 2017, for a fixed price of$5,855/t (~$2.65/lb)

§ Payment of Interest Due May 15, 2017 with respect to its Senior Secured NotesDue 2021: On May 15, 2017, the Company paid the interest payment due May 15, 2017with respect to its 2021 Senior Secured 2021. The Company elected to make a 12.00%annual interest rate PIK Payment for 50% of the interest equivalent to $4.3 million andthe remaining 50% of the interest was paid in cash, at an interest rate of 8.75%equivalent to $3.1 million

2017 2016 Change

Sales of copper cathodes $33.8 $23.5 44.1%Sales of copper contained in ore $2.4 $3.0 -20.1%Cost of sales ($34.7) ($32.0) 8.5%

Gross profit $1.5 ($5.5) -127.0%Operating income ($1.5) ($8.1) -80.9%Net income ($1.8) $78.6 -102.3%Operating cash flows ($1.1) $4.8 -123.6%Capital expenditures ($3.0) ($1.6) 87.5%As of March 31,

Cash and cash equivalents $3.2 $6.1 -47.9%Interest bearing debt, including current portion $194.8 $161.3 20.8%

Exchange Rate (MXN/USD) 20.39 18.02 13.2%

COBRE DEL MAYO 11

$0.8

8

$0.8

6

$0.8

5

$0.8

4

$0.9

2

$0.8

9 $1.1

5

$1.2

4

$0.9

3

$1.0

7

$1.5

4

$1.0

4

$1.1

1

$1.1

1

$1.2

2

$0.00

$0.20

$0.40

$0.60

$0.80

$1.00

$1.20

$1.40

$1.60

1Q16 2Q16 3Q16 4Q16 1Q17

$/t

Mining ($/t moved) Crushing ($/t crushed) HGS ($/t fed)

$0.49

$0.54

$0.72

$0.70

$0.59

$0.16

$0.19

$0.18

$0.21

$0.16

$0.00

$0.10

$0.20

$0.30

$0.40

$0.50

$0.60

$0.70

$0.80

1Q16 2Q16 3Q16 4Q16 1Q17

$ / l

b C

u Pr

oduc

ed

Processing G&A

1Q17 1Q16 Change

Cu Cathode Produced (M lbs) 12.29 11.12 10.5%

Mining cost $1.36 $1.29 $0.06Crushing cost $0.22 $0.19 $0.04High-Grade System ("HGS") $0.04 $0.06 ($0.02)Processing cost $0.59 $0.49 $0.10Other production costs $0.18 $0.20 ($0.02)General and Administrative Expenses $0.13 $0.15 ($0.02)- Sale of Ore for Concentrate ($0.19) ($0.27) $0.07

C1 Cash Cost ($/lb) $2.33 $2.11 $0.22% Change 10.4%

CDM’s C1 Cash Costs & Other Operating Metrics

Cu Cathode Produced & C1 Cash Cost

Operating Metrics

Mine$1.36

Crush$0.22HGS

$0.04

Processing$0.59

Other$0.18

G&A $0.13

C1 CC Integration* ($/lb)

* Excluding sales of ore for concentrate

COBRE DEL MAYO 12

Updated 43 – 101 Reserves and Resources completed in 4Q15§ Updated 43-101 Reserve & Resource Report released in November 01, 2015 (published December 12, 2015)

§ Optimizing both copper cathode (CDM) and copper concentrate (Kupari) production of the Piedras Verdes deposit (“PV Operations”)

§ Reserves of 846 kt of copper contained in ore with a mine life of 14 years

Summary Mineral Reserves and Resources

Ore (kt) Grade (TCu%) Contained Cu (t)Proven 174,500 0.30 524,000

Probable 117,310 0.28 328,000

Total Proven and Probable 291,810 0.29 846,000Waste 551,320

Strip Ratio 1.90x

Ore (kt) Grade (TCu%) Contained Cu (t)Measured 215,980 0.29 626,000

Indicated 236,810 0.27 639,000

Measured and Indicated 452,790 0.28 1,266,000Inferred 5,200 0.26 1,400

Estimated Reserves

Estimated Resources

§ PV Operations Highlights for Remaining Life of Mine:

— Average production from 2016 to 2026 of 38.7 kt/yr (of copper cathode and copper contained in concentrate), declining gradually as mining ends in 2030 and until leach out period is completed

— LOM C1 Cash Costs for the PV Operations of $ 1.78/lb (excluding royalties)

— Sustaining LOM Capital Costs for the PV Operations of $212 M

§ CDM Operations Highlights:

— Average copper cathode production from 2016 to 2026 of 28.6 kt/yr (78 tpd) declining gradually throughout 2034

— Average ore for concentrate sold to Kupari Metals from 2016 to 2026 of 2,055 kt/yr (5,625 tpd) at an average grade of 0.52% TCu

— LOM C1 cash cost (including by-product credits from the sales of ore to Kupari Metals) of $1.77/lb

— Unleveraged Net Present Value at a 12% discount rate of $110 M

COBRE DEL MAYO 13

Updated 43 – 101 Reserves and Resources completed in 4Q15

§ The Piedras Verdes deposit is mined in multiple phases.

— The LOM plan features 14 pit phases of varying sizes. Active pit areas and planned phases merge into one large ultimate pit

— The pit sequencing sees the Western phases mined to final limits ahead of the Eastern phases, creating significant backfill dump space toshorten waste hauls

§ Currently, the Cerro Chato trend is being drilled, the resource will be updated by 1Q18

Piedras Verdes Pit Phase Solids

F1S

F1W F1N F2

F2G

F3WF4M

F8B

F8A

F8D

FT

F9AF6

F9B

F3NF3E

F8C

FO

II. Copper Market

COBRE DEL MAYO 15

Incentive Price of Copper

§ WoodMack1 defines the Incentive Price of Cu as the minimum price required to incentivize sufficient new production to keep the market in balance(between 2019 & 2026 additional 4.5Mt/yr of Cu would be required for the physical market to be in balance)

§ Given the current economic context, mining companies now demand higher IRR’s to commit to build a project. WoodMack therefore uses 3Incentive Price scenarios considering a range of hurdle rate risk-adjusted IRR’s on a pre-tax 100% equity basis for the additional 4.5Mt/yr

12% IRR è $3.03/lb 15% IRR è $3.62/lb 20% IRR è $3.81/lb

§ With the passage of time, the absence of new copper projects, and in the context of the natural decline in production as mines reach the end of theireconomic life, the growth of supply will be substantially less that the growth in demand even in a scenario with low industrial growth

§ According to the report of Wood Mackenzie, over the next ten years the demand is expected to grow at an average rate of 1.6% annually.Meanwhile the forecast of the supply considering the highly probable projects indicates that it will decrease by an annual average rate of 1.9%. As aresult, the forecasted supply deficit will be in the order of 5.4Mt by 2026.

1. Source: Wood Mackenzie “Global Copper Mine Supply Summary”, released February 2017.

Mined Cu supply gap, project requirement for capacity, and risk adjusted incentive price for greenfield projects

COBRE DEL MAYO 16

$2.57*

$0.00

$1.00

$2.00

$3.00

$4.00

$5.00

$6.00

$7.00

$8.00

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020

US$/lbCu

Year

W War 1 W War 2

Depletion of larger, cheaper, high grade copper deposits

Copper SX/EW technology

changes Copper price curve

Old high grade mining and

smelting technology

Costs fall due to new Flotation

technology

Costs rising as large mines

depleting and Chindia demand

3 4 6 3 4 6 5 7

LowerCopper PriceCycles (Duration inYears) *Spotcopper priceas ofMay31,2017foryear2017

5

The Price of Copper Behaves Cyclically

Historical Copper Price $/lb in Constant March, 2016 USD

§ We are 5 years into a bear market for copper

— Down cycles have never lasted longer that 7 years and are more typically 4 to 6 years

§ Current copper price is affected by decisions to develop and expand mines that were taken in a higher Cu price environment§ The copper price used for year 2017 is the spot price of May 31, 2017 at $2.57/lb

III. Appendix

COBRE DEL MAYO 18

70.2

75.0

65.3

56.5

55.4

58.6

50.8

56.9

61.9

$2.4

0

$2.4

0 $2.6

9

$2.2

4

$2.1

1

$2.2

0 $2.7

1

$2.3

5

$2.3

3

$0.00

$0.50

$1.00

$1.50

$2.00

$2.50

$3.00

$3.50

0

10

20

30

40

50

60

70

80

90

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$/lbtpd

Cathode Production (tpd) C1 Cash Cost ($/lb)

$38.6

$46.5

$41.2

$58.3

$34.5

$35.6

$34.7

$36.9

$37.8

$0

$10

$20

$30

$40

$50

$60

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$M

$7.1

$9.1

$4.8

$2.6

$1.6

$2.2

$2.4

$2.4

$3.0

$0

$1

$2

$3

$4

$5

$6

$7

$8

$9

$10

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$M

$43.

1

$46.

0

$30.

4

$23.

9

$23.

5

$24.

8

$22.

4

$26.

6

$33.

8

$3.4 $3

.0

$1.3

$3.0

$3.0

$2.5

$2.6 $2

.9

$2.4

$0

$10

$20

$30

$40

$50

$60

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$M

Cathode Sales ($M) Sales of Ore ($M)

Summary of Historical Financials

CDM Sales: Cathode Sales and Sales of Ore

Operating Costs1 Capital Expenditures

1. Operating cost exclude: Depreciation & amortization, change in Cu process inventory, ARO amortization, external exploration expenditure, and royalties

Cathode Production & C1 Cash Costs

COBRE DEL MAYO 19

Kupari Acquisition

§ During 4Q14, Cobre del Mayo acquired 40% of the common stock of Kupari Holdings, which owns the flotation plant adjacent to the PiedrasVerdes Mine. As a result, Cobre del Mayo now accounts for its 40% participation in Kupari Holdings by using the equity method

§ Cobre del Mayo’s participation in Kupari Holdings:

— Simplifies and optimizes ore allocation among processes

— Facilitates process improvements that involve both heap leaching and flotation

— Diversifies operational risk across two processes and products

— Provides for close cooperation to the joint development of projects and joint process optimization

$2.4

0

$2.4

0

$2.6

9

$2.2

4

$2.1

1

$2.2

0

$2.7

1

$2.3

5

$2.3

3

$2.3

0

$2.3

0

$2.5

0

$1.9

9

$1.9

6

$2.0

7 $2.5

4

$2.2

7

$2.3

1

$0.00

$0.50

$1.00

$1.50

$2.00

$2.50

$3.00

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$/lb

CDM C1 CC CDM Adjusted C1 CC

$14.

3

$10.

0

($2.

7)

($20

.9)

($2.

1)

($2.

4)

($4.

7)

($2.

3)

$5.4

$16.

0

$12.

4

($0.

4)

($17

.4) ($0.

2)

($0.

6)

($3.

7)

($0.

7)

$6.2

($25)

($20)

($15)

($10)

($5)

$0

$5

$10

$15

$20

1Q15 2Q15 3Q15 4Q15 1Q16 2Q16 3Q16 4Q16 1Q17

$ M

CDM EBITDA ($) CDM Adjusted EBITDA

Adjusted 4Q16 C1 Cash CostAdjusted 4Q16 EBITDA