MSA.TO · 2026-03-31 12:00:00

BVC: MINEROS TSX: MSA OTCQX: MNSAF MINEROS.COM.CO Mineros Announces Updated Prefeasibility Study for the Porvenir Project and Highlights Emerging Porvenir Polymetallic District

Economic Studies

BVC: MINEROS TSX: MSA OTCQX: MNSAF MINEROS.COM.CO

Mineros Announces Updated Prefeasibility Study for the Porvenir Project and

Highlights Emerging Porvenir Polymetallic District

(all amounts expressed in U.S. dollars unless otherwise stated)

Medellín, Colombia – March 31, 2026 – Mineros S.A. (TSX: MSA, OTCQX: MNSAF, BVC: MINEROS)

(“Mineros” or the “Company”) is pleased to announce the results of the updated prefeasibility study for

the Hemco Property (the “2026 PFS” ) including its 100% owned Porvenir polymetallic project (“Porvenir

Project” or “Porvenir”) located within the Compan y’s Hemco Property in northeastern Nicaragua. In

addition, the Company has updated Mineral Resource and Mineral Reserve estimates as of December 31,

2025, for its operating Panama and Pioneer mines.

A National Instrument 43-101 (“NI 43-101”) technical report entitled, “NI 43-101 Technical Report Hemco

Property, Region Autonoma de la Costa Caribe No rte, Nicaragua”, issued and effective March 31, 2026

(“The Hemco Technical Report”), prepared by SLR Consulting (Canada) Ltd. (“SLR”) will be filed on SEDAR+

in accordance with applicable Canadian securities laws.

The 2026 PFS confirms Porvenir as a high-margi n, stand-alone underground operation and the

cornerstone of an emerging district including the Guillermina, Leticia, and San Antonio deposits.

HIGHLIGHTS:

• Robust Economics:

◦ After-tax net present value, using a 5% discount rate (“NPV5%”) of $460 million, after-tax

internal rate of return (“IRR”) of 37.9% and 2.0-years payback base case1

◦ After-tax free cash flow at $3,150/oz Au of $727 million for the life of mine

◦ All-in Sustaining Cost (“AISC”)2 of $1,295/oz of gold equivalent (“AuEq”)

◦ Initial capital cost requirement of $206.8M

• Strong Production Profile: Average annual sales of 72.3Koz AuEq, 54.5 Koz Au, 190 Koz Ag, 28 Mlb

Zn and 3.75 Mlb Cu over years 1 to 9 (years of full production) of mine life.

• Stand-alone operation: A 2,000 tonnes per day (“tpd”) proc essing plant with associated

infrastructure including tailing facility, power supply via dedicated 34.5 kV distribution line and

wastewater treatment plant.

1 Base case consensus forecast prices of $3,150/oz Au, $45.00/oz Ag, $4.72/lb Cu, and $1.22/lb Zn

2 After-tax free cash flow and AISC per ounce of AuEq sold are calculated at the project level based on the 2026 PFS life of mine economic analysis and are not comparable to

the non-IFRS financial measures and non-IFRS financial ratios reported in the Company’s management’s discussion and analysis.

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• Optimized Flowsheet: Metallurgical testing has confirme d a process involving flotation and

cyanidation, enabling the recovery of copper and zinc concentrates alongside gold-silver doré.

• District Scale Potential: Updated Mineral Resource estimates for Porvenir, Guillermina, Leticia,

and San Antonio reinforce a district-scale mineralized system centered on Porvenir infrastructure.

• Porvenir Deposit Mineral Reserves: Updated Mineral Reserves as of December 31, 2025:

◦ Proven and Probable Mineral Reserves : 6,477 Kt averaging 3.53 g/t AuEq 3, 2.86 g/t Au,

12.27 g/t Ag, 2.61% Zn and 0.37% Cu, containing 736 Koz AuEq, 596 Koz Au, 2,555 Koz Ag,

372 Mlb Zn, and 52 Mlb Cu.

▪ Proven Mineral Reserves: 650 Kt averaging 4.25 g/t AuEq, 3.50 g/t Au, 14.07 g/t

Ag, 2.54% Zn and 0.50% Cu, containing 89 Koz AuEq, 73 Koz Au, 294 Koz Ag, 36

Mlb Zn, and 7 Mlb Cu.

▪ Probable Mineral Reserves: 5,827 Kt averagi ng 3.45 g/t AuEq, 2.79 g/t Au, 12.07

g/t Ag, 2.61% Zn and 0.35% Cu, cont aining 647 Koz AuEq, 523 Koz Au, 2,261 Koz

Ag, 336 Mlb Zn and 45 Mlb Cu.

Daniel Henao, President and Chief Executive Office r of Mineros, commented: “Porvenir's economics are

compelling, a $460 million NPV at a 5% discount, near 40% IRR, and 2-year payback speak for themselves.

What excites us most is that Porvenir is just the beginning of a confirmed polymetallic district. Nearby

deposits like Guillermina, Leticia, and San Antonio sit within striking distance of shared and scalable

infrastructure, and we believe we are standing on a district that has the potential to grow Mineros’

operations exponentially over the coming decade.”

PORVENIR POLYMETALLIC DISTRICT & PORVENIR PROJECT

The 2026 PFS and ongoing exploration work mark an important milestone, supporting Mineros’ view of

an emerging polymetallic district with gold, silver , zinc, and copper associated with an intermediate

sulphidation epithermal system. The district is centered on the Porv enir Project and includes several

nearby deposits and early-stage exploration targets. This clustering highlights the presence of a coherent,

district-scale mineralized system.

The 2026 PFS covers the Hemco Property in its entirety. As Panama and Pioneer are producing mines, the

study's development focus is on the Porvenir Project, the Company’s principal development-stage project

within the district. Concurrently, Mineros has completed updated Mineral Resource estimates for the

Guillermina, Leticia, and San Antonio deposits. On a consolidated basis, Porvenir hosts approximately 736

Koz AuEq 3 in Proven and Probable Mineral Reserves. In addition, Measured and Indicated Mineral

Resources, exclusive of Mineral Reserves, total approximately 406 Koz AuEq4, with a further 313 Koz AuEq

classified as Inferred Mineral Resources on all four deposits. Mineros believes centralized infrastructure

3 Mineral Reserves in terms of gold equivalent ounces (“AuEq”) have been calculated for purposes of this press release based on the assumptions set

out in Note 8 to Table 3, below, and are not disclosed in the Hemco Technical Report.

4 Mineral Resources in terms of AuEq have been calculated for purposes of this press release based on the assumptions set out in Note 10 to Table 2,

below, and are not disclosed in the Hemco Technical Report.

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at Porvenir could serve as a processing hub for the district, with potential to significantly extend mine life

beyond the current plan.

Relative to the previous prefeasibility study, this ad ditional technical work has strengthened the project

design, supported a better understanding of the underground mine plan, and defined an updated

processing flowsheet. The 2026 PFS reflects improve d project economics and supports Porvenir’s

advancement as a robust underground polymetallic development project within the Hemco operations.

Recent exploration and technical work have highlight ed a district-scale mineralized system comprising

several spatially related deposits and targets, including:

 Porvenir Project : An epithermal gold-silver-zinc-copper system in pre-development stage with

updated Mineral Reserves and Mineral Resources, which is the focus of the 2026 PFS.

 Guillermina: An epithermal gold-silver-zinc-copper sy stem at an advanced exploration stage,

located ~3 km north of Porvenir; open along strike and at depth, with updated Indicated and

Inferred Mineral Resources.

 Leticia: An epithermal gold-silver-zinc system at an advanced exploration stage, located ~500 m

northwest of Porvenir; open along strike and at depth, with updated Indicated and Inferred

Mineral Resources.

 San Antonio : An epithermal gold-silver-zinc-copper sy stem at an advanced exploration stage,

located ~500 m southwest of Porvenir; open al ong strike and at depth, with updated Inferred

Mineral Resources.

 Early-stage exploration targets: Mombacho, Pochomil, Apoyo and Madroño, Momotombo which

form part of the Company’s broader exploration pipeline within the Porvenir polymetallic district.

The presence of significant polymetallic mineralization distributed throughout the district reinforces the

potential for continued resource growth and exploration activities which are focused on expanding

Mineral Resources, increasing geological confidence, and advancing the broader district potential

centered on the Porvenir Polymetallic district. (See figure 1)

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Figure 1: Porvenir Polymetallic District, Porvenir, Leticia, Guillermina, San Antonio deposits and

exploration targets. Source: Mineros, 2026

PORVENIR PROJECT OVERVIEW

The Porvenir Project is located within the Bonanz a-Siuna-Rosita Mining Triangle in northeastern

Nicaragua, approximately 420 km northeast of Managua. The project forms part of the Company’s Hemco

Property, which includes the producing Panama and Pioneer underground gold mines, as well as several

advanced-stage and early-stage exploration targets across the district.

Mineralization at Porvenir occurs primarily within the Real McKoy and the Porvenir Norte and Porvenir

Sur zones and is hosted in epithermal veins associated with intermediate sulphidation mineralization and

hydrothermal breccias.

Mining will be conducted using mechanized underground methods. Geomechanical modelling completed

as part of the 2026 PFS has been updated to support optimized stope design and improved underground

mining parameters, with bench-and-fill and sub-level stoping as the primary extraction methods.

Ore from the Porvenir underground mine will be processed in a new dedicated processing facility

incorporating flotation and cyanidation circuits. Th e optimized flowsheet enables the recovery of copper

and zinc concentrates in addition to gold-silver doré.

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Economic Analysis

The economic analysis of the Porvenir Proj ect demonstrates that the Mineral Reserves

are economically viable at the consensus forecast prices of $3,150/oz Au, $45.00/oz Ag, $4.72/lb Cu, and

$1.22/lb Zn over the LOM. The 2026 PFS Update base ca se economics result in an after-tax NPV at a 5%

discount rate of approximately $460 million, an af ter-tax IRR of 37.9%, and a payback period of

approximately 2.0 years from the start of production.

Initial capital costs are estimated at $206.8 million, including contin gency. Life-of-Mine (“LOM”)

sustaining capital is estimated at $66.2 million, and cl osure and reclamation costs are estimated at $33.4

million.

After-Tax cash flow undiscounted for the LOM of $727 million, see Figure 2 , and the average LOM AISC

per ounce of gold equivalent sold is estimated at $1,295/oz AuEq.

Figure 2: Porvenir Undiscounted After-Tax Free Cashflow. Source: Mineros, 2026

Mine and Processing Plant Operation

The estimated Mineral Rese rves support LOM of 9.2 years at a pe ak production rate of 2,000 tpd. The

LOM plan is designed to minimize upfront capital expenditures without adversely affecting initial cash

flow. The mine plan includes a six-month progressive ramp-up period, gradually increasing to 2,000 tpd in

year one. Underground development is expected to commence two years prior to the start of production.

The proposed Porvenir Plant is designed as a stand- alone facility with a trea tment capacity of 2,000 tpd,

placed within a layout with sufficient capacity fo r future expansions. The plant will utilize an updated

metallurgical flowsheet designed to produce three primary products: copper-lead concentrate containing

gold and silver, zinc concentrate, and gold-silver do ré bars. The comprehensive process includes primary

($140)

($90)

($40)

$10

$60

$110

($780)

($580)

($380)

($180)

$20

$220

$420

$620

Y - 3 Y - 2 Y - 1 Y 1Y 2Y 3Y 4Y 5Y 6Y 7Y 8Y 9 Y 1 0

Yearly Cash Flow ( US$) mllions

Cumulative Cashflow ( US$ mllions )

Undiscounted After-Tax Free Cashflow

After-Tax Cashflow Undiscounted Cumulative After-Tax Cashflow Undiscounted

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crushing, followed by a grinding circuit featuring a SAG mill and two parallel ball mills. The recovery circuit

integrates specialized stages such as flash flotat ion, conventional Cu-Pb and zinc flotation, and a

cyanidation circuit for flotation tailings. The facilit y includes a Merrill-Crowe recovery system, a cyanide

destruction circuit for tailings detoxification, and an industrial wastewater treatment plant equipped with

an acid mine drainage module.

The Porvenir Plant is designed to achieve LOM metallurgical recoveries rates of 88.4% for gold, 84.9% for

silver, 84.5% for zinc, and 69.9% for copper. Under the 2026 PFS, the Porvenir Project is expected to deliver

average annual sales of 72.3 Koz AuEq5, 54.5 Koz Au, 190 Koz Ag, 28 Mlb Zn and 3.75 Mlb Cu over years 1

to 9 (years of full production) of mine life. See Figure 3

Figure 3: Life of Mine Payable Gold equivalent Source: Mineros, 2026

Sensitivity analysis for the base case is provided in Table 1.

5 Payable Gold equivalent is calculated as Au payable oz + (Ag payable oz * $45.00/oz Ag / $3,150/oz Au) + (Zn payable lb * $1.22/lb Zn /

$3,150/oz Au) + (Cu payable lb * $4.72/lb Cu / $3,150/oz Au)

83 84

62 65 65

Y 1Y 2Y 3Y 4Y 5Y 6Y 7Y 8Y 9 Y 1 0

Life of Mine Payable Gold equivalent

Payable Gold Equivalent (Koz)

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Table 1: After-tax sensitivity analysis

Gold Price

($/oz Au)

NPV10%

($000)

NPV5%

($000)

2,520 152,378 263,836

2,835 221,702 361,851

3,150 (Base Case) 291,026 459,867

3,465 360,238 557,677

3,780 429,309 655,227

The 2026 PFS was managed by Mineros, completed by BISA Ingenieria de Proyectos S.A. of Lima, Peru

(“BISA”), and reviewed by SLR. Both BISA and SLR are independent of Mineros.

PORVENIR MINERAL RESOURCES AND MINERAL RESERVES ESTIMATES

Porvenir Deposit Mineral Resources

Porvenir Project Mineral Resources set out in Table 2 were estimated by Mineros and reviewed by SLR.

The updated Mineral Resource estimate effective December 31, 2025, accounts for updated metal prices,

cost estimates, metallurgical reco veries, and resource reporting usin g an $80/t NSR cut-off for sub-level

stoping resource shapes.

Table 2: Porvenir Mineral Resources – Effective December 31, 2025

Mineral

Resource