ARIS MINING ANNOUNCES POSITIVE PEA RESULTS FOR THE TOROPARU GOLD PROJECT PEA confirms long-life, low-cost open pit gold operation in Guyana with 25.2% IRR and $1.8 billion after-tax NPV5% at $3,000/oz gold
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ARIS MINING ANNOUNCES POSITIVE PEA RESULTS FOR THE TOROPARU GOLD PROJECT
PEA confirms long-life, low-cost open pit gold operation in Guyana with 25.2% IRR and
$1.8 billion after-tax NPV5% at $3,000/oz gold
Vancouver, Canada, October 28, 2025 – Aris Mining Corporation (Aris Mining or the Company) (TSX: ARIS; NYSE -
A: ARMN) announces positive results from the recently completed preliminary economic assessment (PEA) of its
100%-owned Toroparu Gold Project (Toroparu or the Project) in Guyana. The PEA confirms Toroparu as a large-scale,
long-life open pit gold project with robust economics — 21.3-year mine life, 235 koz of average annual gold
production, and $ 1.8 billion after-tax NPV5% at $3,000/oz gold. The full P EA report is available on the Company’s
website and SEDAR+ profile at www.sedarplus.ca and is filed with the U.S. Securities and Exchange Commission (SEC)
at www.sec.gov. All amounts are in U.S. dollars unless otherwise indicated.
Neil Woodyer, CEO, commented: “The Toroparu PEA outlines a major new growth and diversification opportunity for
Aris Mining. After the GCM Mining and Aris Gold merger and the arrival of our management team in September
2022, we paused the Project’s previous construction plans to reassess the Project on a first -principles basis, which
included completing a new geological interpretation, updati ng the mineral resource estimate, and undertaking
optimization studies. The result is a robust PEA that establishes a solid path forward. This is our second major
technical study this year, following the Soto Norte Prefeasibility Study (PFS) in September, and together they
demonstrate the strength of our growth pipeline beyond Segovia and Marmato . Aris Mining has initiated a PFS for
Toroparu, targeted for completion in 2026, with the objective of advancing the project toward construction.”
Project Highlights
Low-Risk Development Strategy for a Large-Scale, Open Pit Mine
• Measured and indicated mineral resources of 126.9 million tonnes (Mt) at 1.30 grams per tonne ( g/t) Au
containing 5.3 million ounces (Moz) of gold and inferred mineral resources of 22.9 Mt at 1.6 g/t Au containing
1.2 Moz of gold. See Table 4 for more detailed technical disclosure.
• Conventional truck-and-shovel open pit operation with a strip ratio of 4.7 to 1 (waste to mill feed).
• Mill capacity of 7.0 million tonnes per annum (Mtpa) – a scale that supports attractive investment returns and
extends mine life to over 20 years.
Production and Economics
• Production of doré and copper concentrates containing 5.0 Moz gold, 4.9 Moz silver, and 260 million pounds
(Mlb) of copper over the life-of-mine.
• Average annual life-of-mine gold production of 235 thousand ounces (koz).
• Low life-of-mine cash costs1 of $826/oz2 Au and all-in-sustaining costs (AISC) of $1,289/oz2 Au.
• Significant by-product credits from copper and silver.
Capital and Returns
• Base case gold price: $3,000/oz, supporting life-of-mine payable gold sales of $14.7 billion.
• Initial construction capital of $820 million, including pre-production costs and $96 million of contingency.
o This reflects a $38 million reduction in initial capital compared to a fleet -purchase scenario, as the $7 3
million cost of the initial mining fleet is reduced to approximately $35 million of upfront and construction-
period payments under an OEM lease . The OEM leasing strategy ensures access to modern, well -
supported equipment under comprehensive maintenance and parts-supply programs over the long +20
year mine life.
o An additional $138 million of committed funding from a historical precious metals streaming agreement,
further reducing the upfront funding requirement to $682 million.
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• After-tax NPV5% of $1.8 billion, IRR of 25.2%, and payback in 3.0 years from the start of operations.
• Annual EBITDA averaging $443 million over the life of the mine.
• Strong leverage to higher gold prices, at $3,600/oz the NPV5% increases to $2.7 billion with IRR of 32.6%.
Figure 1 – Toroparu annual processed gold grade and total gold production
Figure 1 illustrates Toroparu’s planned gold production and processed grade profile over the 21.3 -year mine life
outlined in the PEA. The average annual gold production is projected at 235 koz, peaking at 278 koz in Year 18,
supported by a consistent milled gold grade ranging from 1.0 to 1.3 g/t. The long, steady production profile
demonstrates the grade continuity of the deposit.
The open pit optimization and designs were based on a $1,950 per ounce gold price and a 0.45 g/t Au cut-off grade.
This conservative approach indicates meaningful upside potential for resource growth and mine-life expansion in a
higher gold price environment.
To efficiently manage the owner-operated mining fleet over the Project’s long life, the initial mining fleet—including
excavators, dozers, haul trucks, and support equipment —is expected to be secured through Original Equipment
Manufacturer ( OEM) lease financing ahead of first production. Replacement equipment will be renewed on a
scheduled basis under similar arrangements, ensuring access to modern, reliable, and well -supported equipment
throughout the pre-production and 21.3-year operating period s. The OEM leasing and service agreements are
expected to include comprehensive maintenance and parts supply programs, providing consistent technical support,
minimizing downtime, and optimizing equipment availability and lifecycle performance across the Project’s
operations.
Plant commissioning will be supported by a large pre -production stockpile of approximately 6.1 million tonnes,
representing most of the first year’s mill feed. This stockpile, built during the construction period, provides a strong
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foundation for a smooth, low -risk start-up and consistent throughput as operations ramp up. With stockpiled mill
feed available ahead of commissioning, processing is expected to reach nameplate capacity of 7.0 Mtpa within the
first operating year, supporting reliable early cash flow and efficient optimization of plant performance.
The process flow sheet has been designed to efficiently recover copper as a flotation concentrate. In earlier project
designs, the flotation circuit was deferred to reduce initial capital costs; however, by incorporating the flotation circuit
from the outset, the current design effectively manages copper in the mill-feed while generating a valuable by -
product that contributes positively to project revenues.
Technical Report Availability
A complete National Instrument 43 -101 – Standards of Disclosure for Mineral Projects (NI 43 -101) compliant
Technical Report titled “ NI 43 -101 Technical Report Preliminary Economic Assessment for the Toroparu Project,
Cuyuni-Mazaruni Region, Guyana ” dated October 28, 2025 and with an effective date of October 21, 2025 (the
Technical Report) has been filed on SEDAR+ and with the SEC on EDGAR, and is also available on the Company’s
website at https://aris-mining.com/operation/toroparu/technical-report/
Guyana’s next major gold mine
Guyana’s mining sector is advancing rapidly, with the Oko West project leading a new generation of large-scale gold
developments. Like Oko West, Toroparu is a substantial, open-pittable gold deposit with growing government support
for responsible mine development. Oko West’s rapid progress highlights the attractive regulatory and investment
environment in Guyana, paving the way for Aris Mining to follow with Toroparu as Guyana’s next major gold mine.
Figure 2 – Toroparu location map
Both projects demonstrate Guyana’s emergence as a new frontier for large -scale, responsibly developed gold
mining in the Americas.
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Table 1 – Toroparu follows Oko West’s lead
Feature Toroparu (Aris Mining) Oko West (G Mining Ventures)3
Stage PEA completed, PFS underway Feasibility Study completed (Apr 2025) ,
receipt of environmental permit (Sept 2025) ,
secured project financing commitments and
formal construction decision (Oct 2025)
Mining method Open pit, conventional truck and shovel Open pit, conventional truck and shovel (81%
of mill feed) , and
Underground, mechanized long hole open
stoping with cemented rock fill (19% of mill
feed)
Open Pit Mineral
Resources
123.3 Mt at 1.28 g/t Au containing 5.1 Moz
(measured and indicated), and 11.4 Mt at
1.13 g/t Au containing 0.4 Mo z (inferred)
73. 0 Mt at 2. 00 g/t Au containing 4.7 Moz
(indicated), and 1.5 Mt at 1.06 g/t Au
(inferred)
Underground
Mineral Resources
3.6 Mt at 2.05 g/t Au containing 239 koz
(measured and indicated), and 11. 5 Mt at
2.07 g/t Au containing 763 koz (inferred)
7.2 Mt at 3.09 g/t Au containing 718 koz
(indicated), and 3.6 Mt at 2.93 g/t Au
containing 337 koz (inferred)
Open pit stripping
ratio (waste to mill
feed )
4.7 6.8
Processing capacity 7.0 Mtpa Life of Mine (LOM) average of 6.2 Mtpa
Flowsheet Gravity , flotation & CIL & Gravity & CIL
Products Doré and copper concentrate s Doré
Average annual gold
production
235 koz per year for 21.3 years 350 koz per year for 12.3 years (reserves only)
Average AISC/oz $1, 289 $1,123
Life of mine
production
5.0 Moz gold, 4.9 Moz silver, and 2 60 Mlb of
copper
4.3 Moz gold (reserves only)
Initial capital cost $820 million $1.0 billion
Key economic
indicators
At $ 3,000 /oz (stream financing included ):
NPV 5%: $1.8 billion
IRR: 25.2 %
Payback period: 3.0 years
At $ 3,000/oz (stream financing excluded):
NPV 5%: $2.3 billion
IRR: 25.5%
Payback period: 2.8 years
At $3,000/oz:
NPV 5%: $ 3.2 billion
IRR: 35%
Payback period: 2.1 years
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Table 2 – Toroparu economic evaluation sensitivity to gold price
Gold price
Indicator $2,400/oz $2,600/oz $2,800/oz $3,000/oz
Base case $3,200/oz $3,400/oz $3,600/oz
After-tax NPV5% ($M) $944 $1,231 $1,518 $1,805 $2,091 $2,378 $2,664
After-tax IRR (%) 16.6% 19.6% 22.5% 25.2% 27.7% 30.2% 32.6%
Payback period (years) 4.4 3.7 3.3 3.0 2.7 2.5 2.3
The sensitivity analysis in Table 2 shows that at higher gold prices, returns increase substantially beyond the
attractive levels of the base case scenario.
The base-case economic analysis includes a total initial funding contingency of $96 million, which is based on
15% on all direct and indirect cost items during the construction period (excluding equipment lease payments)
and a 10% contingency on pre-production mining costs. The initial funding contingency is intended to cover
normal estimating uncertainties as the Project advances to the PFS level. Operating costs were developed using
detailed unit-cost methodologies supported by zero -based estimates for key consumables and labour, and
benchmarked and indexed against comparable Latin American and Guiana Shield operations. To reflect operating
cost uncertainty, an additional 10% operating cost contingency has been applied to mining and processing costs
in the economic analysis.
The economic analysis also includes the historic precious metals stream agreement with Wheaton Precious
Metals International Ltd (Wheaton), originally entered into in 2013 and amended in 2015, when Toroparu was
owned by Sandspring Resources Ltd., a single-asset junior developer. Under this agreement, Wheaton may elect
to provide $138 million in construction funding following completion of a full development plan, in exchange for
the right to purchase 10% of Toroparu’s gold production and 50% of its silver production at fixed prices of $400/oz
and $3.90/oz, respectively, with both prices subject to escalation beginning on the fourth anniversary of
commercial production. The parties intend to explore opportunities for amending the terms of the agreement to
align with the updated project parameters.
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Table 3 – Toroparu economic evaluation results
Key indicators Units Total
Total gold produced over life of mine Moz 5.0
Initial life of mine at milling rate of 7.0 Mtpa Years 21.3
Average annual life of mine gold production koz 235
Life of mine average cash cost2 $/oz Au 826
Life of mine average AISC2 $/oz Au 1,289
Average annual life of mine EBITDA $M 443
Summary cash flow for the life of mine ($M), at $3,000/oz gold price
Revenue from payable gold sales 14,677
Less: royalties 1,193
Less: operating costs, net of by-product silver and copper 4,043
Less: sustaining capital 1,069
Operating margin 8,372
Less: income tax 2,174
After-tax cash flow 6,198
Less: initial capital including pre-production costs, and $96 million contingency 820
Credit: construction funding, Wheaton precious metals stream financing (138)
Less: other non-sustaining capital expenditures over LOM 198
Less: closure costs 35
Net cash flow, before losses from Wheaton precious metals stream financing 5,283
Less: losses from Wheaton precious metals stream financing 1,356
Net cash flow 3,927
After-tax indicators, at $3,000/oz gold price (base case):
NPV at 5% discount rate $M 1,805
IRR % 25.2
Payback period (from start of operations) Years 3.0
After-tax indicators, at $3,600/oz gold price:
NPV at 5% discount rate $M 2,664
IRR % 32.6
Payback period (from start of operations) Years 2.3
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Table 4 - Toroparu mineral resources effective October 21 , 202 5
Area Classification Tonnes
Mt
Grade
gold
(g/t)
Grade
silver
(g/t)
Grade
copper
(%)
Contained
gold
(koz)
Contained
silver
(koz)
Contained
copper
(Mlb)
Open pit
Measured 48.4 1.31 1.8 0.14 2,030 2,747 150
Indicated 74.9 1.26 1.2 0.08 3,041 3,008 127
Measured + Indicated 123.3 1.28 1.5 0.10 5,071 5,755 276
Inferred 11.4 1.13 0.7 0.04 414 275 9
Underground
Measured 0.1 1.89 0.4 0.03 8 2 -
Indicated 3.5 2.05 0.7 0.05 231 74 4
Measured + Indicated 3.6 2.05 0.7 0.05 239 76 4
Inferred 11.5 2.07 0.7 0.04 763 263 10
Total
Measured 48.5 1.31 1.8 0.14 2,038 2,749 150
Indicated 78.4 1.30 1.2 0.08 3,272 3,082 131
Measured + Indicated 126.9 1.30 1.4 0.10 5,310 5,831 280
Inferred 22.9 1.60 0.7 0.04 1,177 538 19
Notes:
1. Mineral resources are not mineral reserves and have no demonstrated economic viability.
2. The mineral resource estimate was prepared under the supervision of or was reviewed by Pamela De Mark, P .Geo., Senior
Vice President Geology and Exploration of Aris Mining, who is a qualified person as defined by NI 43-101.
3. Totals may not add up due to rounding.
4. Mineral resources were estimated using a gold price of $1,950 per ounce. Open pit mineral resources are reported above a
cut-off grade of 0.45 g/t gold within an optimized pit shell and underground mineral resources are reported above a cut -off
grade of 1.5 g/t gold within optimized stope shapes.
5. There are no known legal, political, environmental, or other risks that could materially affect the potential development of
the mineral resources.
Endnotes
1. All references to Cash costs ($ per oz sold), AISC ($ per oz sold) and EBITDA are non-GAAP financial measures in this document. These
measures are intended to provide additional information to investors. They do not have any standardized meanings under IFRS, and therefore
may not be comparable to other issuers and should not be considered in isolation or as a substitute for measures of performance prepared
in accordance with IFRS. Refer to the Non-GAAP Financial Measures section of this document.
2. Cash cost per ounce, and AISC per ounce are calculated inclusive of open pit mining costs; treatment, transport and refining costs; processing
and surface costs; G&A and other costs; and are net of by -product credits for silver and copper. These metrics are calculated on a payable
gold ounce basis.
3. Sourced from Oko West Feasibility Study dated April 28, 2025
About Aris Mining
Founded in September 2022, Aris Mining was established with a vision to build a leading South America-focused gold
mining company. Our strategy blends current production and cashflow generation with transformational growth
driven by expansions of our operating assets, exploration and development projects. Aris Mining intends to unlock
value through scale and diversification. The Company is listed on the TSX (ARIS) and the NYSE -A (ARMN) and is led
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by an experienced team with a track record of value creation, operational excellence, financial discipline and good
corporate governance in the gold mining industry.
Aris Mining operates two underground gold mines in Colombia: the Segovia Operations and the Marmato Complex,
which together produced 210,955 ounces of gold in 2024. With expansions underway, Aris Mining is targeting an
annual production rate of more than 5 00,000 ounces of gold, following the commissioning of the second mill at
Segovia, completed in June and ramping up during H2 2025, and the construction of the Bulk Mining Zone at the
Marmato Complex, expected to start ramping up production in H2 2026. In addition, Aris Mining operates the 51%
owned Soto Norte joint venture, where a PFS study is complete on a new, smaller scale development plan which
confirms Soto Norte as a high -quality, long-life project with robust economics and industry-leading environmental
and social design features. In Guyana, Aris Mining owns the Toroparu gold project, where the new PEA is complete
and a PFS is underway.
Colombia is rich in high -grade gold deposits and Aris Mining is actively pursuing partnerships with the Country’s
dynamic small-scale mining sector. With these partnerships, we enable safe, legal, and environmentally responsible
operations that benefit both local communities and the industry.
Additional information on Aris Mining can be found at www.aris-mining.com, www.sedarplus.ca, and on
www.sec.gov.
Aris Mining Contact
Oliver Dachsel
Senior Vice President, Capital Markets
+1.917.847.0063
Lillian Chow
Director, Investor Relations & Communications
Cautionary Language
Qualified Person and Technical Information
The Toroparu Gold Project Preliminary Economic Assessment titled “ NI 43 -101 Technical Report Preliminary Economic
Assessment for the Toroparu Project, Cuyuni -Mazaruni Region, Guyana” was prepared in accordance with NI 43 -101 by the
following Qualified Persons, all of whom are independent of Aris Mining for the purposes of NI 43-101, with the exception of
Pamela De Mark, P .Geo., who is the Senior Vice President Geology and Exploration of Aris Mining:
• Vaughn Duke, Pr. Eng. PMP., Founding Partner and Director, Sound Mining International Limited
• Jan Eklund, P.E., Process Consultant, LogiProc Pty. Ltd.
• Pamela De Mark, P.Geo., Senior Vice President, Geology and Exploration, Aris Mining Corporation
Pamela De Mark, P .Geo., Senior Vice President Geology and Exploration of Aris Mining, is a Qualified Person as defined by NI
43-101, and has reviewed and approved the technical information contained in this news release.
Note that the PEA is preliminary in nature, it includes inferred mineral resources that 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 preliminary economic assessment will be realized.