Endeavour Announces Positive DFS Results FOR the Assafou Project That Underpins the NEXT Phase of Organic Growth
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NEWS RELEASE – LSE & TSX: EDV
ENDEAVOUR ANNOUNCES POSITIVE DFS RESULTS FOR THE
ASSAFOU PROJECT THAT UNDERPINS THE NEXT PHASE OF
ORGANIC GROWTH
HIGHLIGHTS:
• Definitive Feasibility Study confirms Assafou's potential to become a cornerstone asset for Endeavour
highlighting:
› 320kozpa production at AISC of $1,026/oz over first 8 years.
› 16-year mine life based on P&P reserves of 4.4Moz (77.4Mt at 1.76g/t); M&I resources of 5.0Moz
(80.1Mt at 1.93g/t).
› Robust project economics with after -tax NPV (5%) of $2.1 bn and 28% IRR at a gold price of
$2,500/oz, increasing to $5.1bn and 55% at a gold price of $4,000/oz.
› Upfront capital of $ 1,061m based on a scalable 5Mtpa design nameplate capacity gravity / CIL
processing plant ; increased upfront capital reflects changes to site infrastructure, plant
optimisations to de-risk ramp-up and to enable seamless plant expansion in the future.
• Significant exploration potential with over 20 highly prospective targets defined:
› Assafou deposit (5.0Moz M&I resource) mineralisation is open along strike and at depth ; Pala
Trend 3 (0.2Moz maiden M&I resource) satellite located 1km away is mineralised from surface.
› Assafou is the first discovery in a highly prospective and underexplored belt.
• Early works launched including long-lead orders, detailed engineering and design, and key tenders.
• Final investment decision targeted before end-2026, with subsequent 24 – 30 month construction.
• Assafou underpins the Group’s sector-leading organic growth outlook to 1.5Moz, at first quartile AISC,
by 2030.
Abidjan, 23 April 2026 – Endeavour Mining plc (LSE:EDV, TSX:EDV, OTCQX:EDVMF) (“Endeavour”, the “Group”
or the “Company”) is pleased to announce the results of the Definitive Feasibility Study (“DFS”) for the Assafou-
Dibibango (“Assafou”) project on the Tanda-Iguela property in Côte d’Ivoire.
Ian Cockerill, Chief Executive Officer, commented: “We are pleased with the results of the Assafou project DFS,
which confirms the quality and scale of the asset that will underpin the next phase of Endeavour’s organic
growth.
Assafou has the potential to become another cornerstone asset for Endeavour, adding 320koz of production per
year at a first quartile AISC of $1,026/oz, over the first eight years of its 16-year mine life. It will be our lowest-
cost and longest-life mine, further improving our portfolio quality while bolstering the resilience of the business.
The impressive project economics demonstrate our ability to rapidly generate value through the drill bit. Assafou
was discovered for $13 million in 2022 and only four years later has a value of $5.1 billion at aa $4,000/oz gold
price. As we continue to de-risk the project and grow its resource base through exploration, we expect to unlock
even more value.
Since its discovery, the Assafou M&I resource has grown 470%, to over 5 million ounces, and we are increasingly
excited by more than 20 highly prospective satellite targets, in close proximity to the deposit.
Working closely with our supportive in-country stakeholders, we are advancing the project’s mining convention,
and we are targeting a final investment decision before the end of the year. Simultaneously, we have launched
early works, detailed engineering and design, key tenders and long-lead orders to expedite construction.
As we advance Assafou, we will remain disciplined and prioritise maximising free cash flow from every ounce of
gold we produce, ensuring that we continue to deliver sector leading shareholder returns, while we organic ally
grow production to 1.5 million ounces by 2030.”
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Table 1: Assafou Project Highlights
ASSAFOU DFS STRATEGIC TARGETS
P&P Reserve, Moz1 4.4 >3.0
Mine life, years 16 >10
Average annual production, kozpa First 8 years 320 >200 Life of mine 257
AISC, $/oz2 First 8 years 1,026 1st quartile Life of mine 1,062
Post-tax NPV5%, $m2 2,059 n.a.
Post-tax IRR, %2 28 >20
1Based on a $1,500/oz reserve price. 2Based on a gold price of $2,500/oz.
The key operational and economic highlights of the Assafou DFS are summarised in Tables 2 and 3 below.
Table 2: Assafou DFS Summary
OPERATION TYPE
Mine type Open Pit
Plant type 5.0Mtpa Gravity / CIL Plant
RESERVES & RESOURCES1
P&P reserves 77.4Mt at 1.76g/t Au for 4.4Moz
M&I resources (inclusive of reserves) 80.1Mt at 1.93g/t Au for 5.0Moz
Inferred resources 0.9Mt at 2.34g/t Au for 0.1Moz
LIFE OF MINE PRODUCTION
Mine life, years 16
Strip ratio, W:O 6.3
Tonnes processed, Mt 77.4
Grade processed, Au g/t 1.76
Gold contained processed, Moz 4.4
Average recovery rate, % 94
Gold production, Moz 4.1
Average annual production, kozpa 257
Cash costs, $/oz2 952
AISC, $/oz2 1,062
AVERAGE FOR YEARS 1 TO 8
Production, kozpa 320
Cash costs, $/oz 887
AISC, $/oz2 1,026
CAPITAL COST
Upfront capital cost, $m 1,061
ENVIRONMENTAL DATA
GHG Emissions Intensity3, t CO2e/oz 0.59
Energy Intensity, GJ/oz 7.39
1Based on a reserves gold price of $1,500/oz and a resource gold price of $1,900/oz . Reserves and Resources relates to the
Assafou Project and are exclusive of Pala Trend 3 Resources. 2Based on a gold price of $2,500/oz. 3GHG Emissions Intensity
considers only Scope 1 and 2 emissions.
Table 3: Assafou DFS Project Economics
Gold Price $2,000/oz $2,500/oz $3,000/oz $4,000/oz
PRE-TAX
NPV5%, $m 1,625 2,909 4,250 6,934
IRR, %1 23 34 45 66
Payback Period, yr1 4.14 3.01 2.43 1.81
AFTER-TAX
NPV5%, $m 1,074 2,059 3,077 5,113
IRR, %1 18 28 37 55
Payback Period, yr1 4.97 3.52 2.73 1.95
1Payback period and IRR are calculated from the start of commercial production
Endeavour expects to file a Technical Report pursuant to National Instrument 43-101 – Standards of Disclosure
for Mineral Projects (“the NI 43-101”) in respect of the Assafou DFS within 45 days of this news release.
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Overview
The 100% owned Tanda and Iguela exploration permits (“Tanda-Iguela”) are located in the eastern region of Côte
d’Ivoire, approximately 280km northeast of Abidjan, adjacent to the Ghana border. The northern permit, Tanda,
was added to Endeavour’s portfolio in November 2015 following the combination of La Mancha’s Ivorian assets
with Endeavour. Endeavour conducted an initial drilling campaign during 2016 that yielded positive results and
quickly identified the southern permit, Iguela, as having a high degree of geological prospectivity. The Iguela
permit was awarded to Endeavour in May 2017, through Côte d’Ivoire’s permit application process.
Figure 1: Tanda-Iguela Regional Map
A maiden Indicated resource of 1.1Moz (14.9 at 2.33 g/t Au ) was published on 21 November 2022, based on
56,000 metres of drilling, and was subsequently increased to 4.5Moz (70.9 at 1.97 g/t Au) on 29 November 2023,
based on an additional 123,000 metres of drilling . Further exploration and advanced grade control drilling at
the Assafou deposit and exploration drilling at the Pala Trend 3 satellite deposit resulted in an increase in
Measured and Indicated resources to 5.2Moz at 1.91g/t as of 31 December 2025. These resources are based on
an additional 99,000 metres of drilling and include maiden Measured resources, reflecting increased resource
confidence.
As shown in Figure 2 below, the DFS demonstrates Assafou’s potential to deliver 320kozpa at all-in sustaining
cost (“AISC”) of $1,026/oz over the first eight years of operations, with average production of 2 57kozpa and
AISC of $1,062/oz over the 16-year life of mine.
Figure 2: Assafou DFS Production and AISC Profile1
1AISC based on a gold price of $2,500/oz
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The DFS production profile is based on the Assafou deposits’ mineral reserves only, with an effective date of 31
December 2025. The DFS production profile excludes mineral resources outside of reserves and excludes the
maiden Measured and Indicated mineral resource of 4.7Mt at 1.55g/t for 0.2Moz at the Pala Trend 3 satellite
deposit, that was defined following successful exploration drilling during 2025 . Furthermore, n early 70,000
metres of exploration drilling has been completed at nearby satellite deposits, which is expected to contribute
to further resource and reserve increases supporting higher levels of production, particularly in years 12 to 16
of the production profile.
Reserves and Resources
The Assafou Project’s 31 December 2025 reserve and resource estimate is shown in Table 4 below. The resource
estimate is based on a gold price of $1,900/oz and the reserve estimate is based on a conservative gold price of
$1,500/oz.
Table 4: Assafou Project Reserves and Resources
Tonnage Grade Content
On a 100% basis (Mt) (Au g/t) (Au koz)
Assafou Deposit (DFS)
Proven Reserves 21.5 1.87 1,295
Probable Reserves 55.9 1.72 3,085
P&P Reserves 77.4 1.76 4,379
Measured Resource (incl. reserves) 20.8 2.05 1,367
Indicated Resources (incl. reserves) 59.4 1.89 3,606
M&I Resources 80.1 1.93 4,972
Inferred Resources 0.9 2.34 69
Pala Trend 3
Proven Reserves - - -
Probable Reserves - - -
P&P Reserves - - -
Measured Resource (incl. reserves) - - -
Indicated Resources (incl. reserves) 4.7 1.55 231
M&I Resources 4.7 1.55 231
Inferred Resources 1.0 1.68 53
Total Assafou Project
Proven Reserves 21.5 1.87 1,295
Probable Reserves 55.9 1.72 3,085
P&P Reserves 77.4 1.76 4,379
Measured Resource (incl. reserves) 20.8 2.05 1,367
Indicated Resources (incl. reserves) 64.0 1.86 3,837
M&I Resources 84.8 1.91 5,203
Inferred Resources 1.9 2.00 122
1Mineral Resource Estimate effective 31 December 2025. Mineral Reserve Estimate effective 31 December 2025. Mineral Resource and Reserve Estimates follow the Canadian
Institute of Mining, Metallurgy and Petroleum (“CIM”) Definitions Standards for Mineral Resources and Reserves and have been completed in accordance with the Standards of
Disclosure for Mineral P rojects as defined by National Instrument 43 -101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative
accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral Resources that are not Mineral reserves do not have demonstrated
economic viability. Resources were constrained by MII Pit Shell based on a cut -off grade of 0.40g/t at a $1,900/oz gold price. Reserves are based on a cut-off grade of 0.4 0g/t
for oxide, laterite and transitional ore and 0.50g/t for fresh ore and $1,500/oz gold price. Endeavour is not aware of any legal, political, environmental or other risks that could
materially affect the potential development of the mineral resources and mineral reserves other than as noted herein.
For technical notes and drilling results from the Assafou drill programme, please see the Technical Notes section
below.
Mining Operations
The Assafou deposit mineralisation extends from surface to depths in excess of 300 metres and is amenable to
conventional open-pit, drill and blast , mining. The mine planning, resource and cost estimation for the DFS is
based on a contract mining operation with a maximum mining capacity of 53.0 Mt per year, that is expected to
be achieved 5 months after the commencement of mining . Mining capacity is expected to exceed processing
capacity in order to accumulate stockpiles to allow high grade material to be preferentially processed early in
the mine plan.
During the pre-commercial production period approximately 49.3 Mt of pre-stripping is expected to support an
accelerated production ramp up. The projects and operations teams will review opportunities to reduce the
impact of pre-stripping at the Assafou deposit through supplementing the ore feed with near-surface ore from
the Pala Trend 3 deposit, located 1km southwest of the Assafou deposit, as well as additional satellite deposits
in close proximity to the Assafou deposit.
Ore mining is expected to occur in 15-metre benches and 6.0 x 2.5-metre flitches in fresh rock, while waste is
expected to be mined in 5-metre flitches. Smaller excavators will be used for ore loading to decrease dilution.
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Diesel excavators and dump trucks will be used for loading and haulage, with a contractor fleet expected to
comprise of 300-tonne class face excavators for waste mining, and 150-tonne class excavators for ore mining.
Processing Operations
Ore will be processed via a 5.0 Mtpa gravity / carbon-in-leach (“CIL”) processing plant. Over the life of mine, the
plant will be fed with approximately 88% fresh ore and 12% oxide and transitional ore.
The comminution circuit is expected to comprise of two-stage crushing followed by a high-pressure grinding roll
and a ball milling circuit. A primar y gyratory crusher will crush ore to a coarse crush size, followed b y dual
secondary cone crushers. A live primary crushed ore stockpile will provide a buffer storage of primary crushed
ore, with reclaim to feed the secondary crushing unit . Ore will then be fed through the high-pressure grinding
roll circuit that feeds the ball mill. In the event that the secondary crushers or the high-pressure grinding roll
circuits are offline, a fines stockpile located after the high-pressure grinding roll circuit will ensure there is feed
available for the ball mill. The ball mill will mill the ore to 80% passing 106µm (microns).
The milled ore will pass through a gravity circuit comprising two Knelson concentrators for separation and
recovery of coarse free gold, to produce a gravity concentrate for cyanidation and electrowinning that can be
smelted to produce gold doré. High gravity recovery of approximately 70% is estimated.
Coarse feed is returned to the ball mill while screened cyclone overflow is passed via the leach feed thickener
to a CIL circuit containing one pre -leach tank and six CIL tanks , in series, for leaching and absorption. Leach
residence time will be approximately 36 hours. Following leaching and absorption, gold will be recovered from
activated carbon by elution, electrowinning, and gold smelting to produce gold doré.
Extensive multiphase metallurgical test work has demonstrated that ore from the Assafou deposit contains free-
milling gold, with a high proportion of gravity recoverable gold , that is amenable to cyanidation. The majority
of the remaining gold has a high leach extraction potential resulting in an overall gold recovery rate of 94% over
the life of mine.
Operating Cost Summary
Mining operating costs, which are based on Q3 -2025 estimates, were prepared by Endeavour, are based on a
contractor mining model. Process operating cost estimates were prepared by Lycopodium Minerals Canada Ltd
(Lycopodium), who have successfully supported Endeavour through five engineering and construction projects
in West Africa over the last twelve years. General and Administration (“G&A”) cost estimates were also prepared
by Endeavour, as summarised in the table below.
Table 5: Assafou Project Life of Mine Operating Unit Costs (-10/+15%)
UNIT COSTS (US$)
Open Pit Mining and Rehandling $4.11/t mined
Processing $14.38/t processed
G&A $4.48/t processed
Based on Q3-2025 estimates that exclude escalation.
Operating costs have been based on a delivered diesel price of $1.13 per litre and are in line with current local
pricing and, therefore do not reflect any potential pricing impact from current hostilities in the Middle East .
Power will be sourced from the grid supplying 90kV to site via a ring main system providing power from two
different parts of the power grid to increase reliability with an assumed grid availability of 90% and power costs
estimated at $0.13/kWh.
Capital Cost and Infrastructure Summary
The project upfront capital cost, which is based on Q3-2025 estimates, was compiled by Lycopodium with input
from Knight Piésold Pty Ltd (Knight Pi ésold) on the tailings storage facility (“ TSF”), water infrastructure, site
access roads and airstrip, SRK Consulting (UK) Ltd (SRK) for mining cost models and contractor rates, Digby Wells
Environmental Holding Ltd (Digby Wells) for RAP costs, compensation and closure costs , Cabinet Enval SARL
(ENVAL) for environmental assessments, and from ECG Engineering Pty Ltd (ECG Engineering) on the power
infrastructure. Endeavour has provided project specific estimates for mine establishment, facilities, power and
owner’s costs.
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The initial capital cost is summarized in the table below.
Table 6: Assafou Project Upfront Capital Cost Estimate Summary (-10/+15%)
CAPITAL COSTS (US$M)
Pre-production Mining 111.4
Processing Plant Costs 155.8
Reagents and Plant Services 30.9
Site Infrastructure 250.2
Contractor Distributables 65.4
Owner Project and Operations Costs 215.7
Management Costs 50.7
Subtotal 880.1
Pre-production Working Capital 76.3
Contingency 85.4
Taxes and Duties 18.8
Total Upfront Capital Cost 1060.6
Based on Q3-2025 estimates that exclude escalation.
The Assafou project capital cost estimate assumes a contractor mining model, selected due to the additional
fleet flexibility that can accommodate the pre -production mining ramp-up and the potential incorporation of
satellite deposits into the mine plan.
The Assafou project benefits from good surrounding infrastructure, including access to the 90kV ring main
power supply, which will b e diverted via a new 12km transmission line, and access to the A1 national road,
which will be diverted via a n assumed 55km extension around the operation . In addition, backup power
comprised of 28 containerised diesel generators with prime output of 28.0MW has been included in the upfront
capital costs. Furthermore, land provision within the existing min e perimeter for a potential 31.5MW solar
power plant has been provided . The airstrip will be built 10km from the site’s permanent accommodation.
Resettlement of two villages, within close proximity to the project, is required and is included in the upfront
capital cost estimate. The tailings storage facility (“TSF”) is expected to be a High-Density Polyethylene (“HDPE“)
lined cross-valley storage facility , utilising the natural topography of the project area, that will be formed by
multi-zoned earth fill embankments, with a total footprint area (including the basin area) of approximately
239ha for the stage 1 TSF to 265ha for the final TSF. TSF construction will benefit from the high availability of
fresh waste rock from the mining pre -stripping activities. The TSF is designed to a life -of-mine capacity
accommodating a total of 72.0Mt of tailings. The Stage 1 TSF is designed for 7.5Mt, approximately 18 months
storage capacity , and subsequently, downstream raise construction will be used to progressively increase
capacity.
Estimated resettlement disbursements and related costs are i ncluded in the Owner Project and Operations
Costs. These estimates are based on a combination of legislated compensation mechanisms and historic
precedents of similar costs. Final costs are subject to negotiation and agreement between various stakeholders,
including the State of Côte d’Ivoire and local communities.
Figure 3 below highlights the proposed site and infrastructure layout.
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Figure 3: Assafou Project Schematic Site Layout
Ownership, Permitting, Taxes and Royalties
Endeavour acquired the Tanda exploration permit in 201 5, subsequently acquiring the Iguela exploration
permit, which contains the Assafou project, in 2017. The exploitation permit for the Assafou project was granted
in February 2026. Once the new project company is fully incorporated with the State of Côte d’Ivoire as a
shareholder in accordance with Ivorian law, the exploitation permit will be transferred to that company. The
current Mining Code envisages a State free carried interest of 10%.
A corporate tax rate of 25% of gross profit , a royalty rate of 8.0% above a gold price of $2,000/oz and a local
development fund contribution of 0.5% of gold sales were applied in the DFS. Gold royalties in Côte d’Ivoire are
based on a sliding scale with the gold price and vary between 5.0% and 8.0%. A transport and refining charge of
$4/oz Au was also applied.
The Mining Code in Côte d’Ivoire is currently under review, and if the proposed new Mining Code, is passed into
law before the Assafou mining convention is granted, then the level of State participation and the fiscal terms
applicable to the Assafou project may reflect those of the new Mining Code.
Timetable, Early Works and Project Construction
A 24 to 30 month construction period is projected following the final investment decision, which is targeted
before the end of 2026. The final investment decision and the construction period do not reflect any potential
impact from current hostilities in the Middle East.
As shown below in Figure 4, commencement of procurement for long-lead items, detailed engineering and
design, and the EPCM, power and earthworks tenders are already underway.
Figure 4: Assafou Project Early Works
Work Stream Q2-2026 Q3-2026 Q4-2026 Q1-2027 Q2-2027 Q3-2027 Q4-2027 Q1-2028
Early Works
EPCM Award
Detailed Design & Engineering
Order & Procure Long Lead Items
Relocation Action Plan
Project Approvals
Mining Convention Approval
Final Investment Decision
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For FY -2026, growth capital guidance of between $50 – 100 million is expected to be incurred prior to the
approval of the final investment decision. The remaining $961 – 1,011 million of the $1,061 million upfront
capital is expected to be incurred after the final investment decision.
Following the final investment decision, construction is expected to start, initially prioritising the resettlement,
which is on the critical path, and the site infrastructure and earth works. Subsequently tailings and water dam
construction, then power supply and process plant construction will commence.
The critical path includes the resettlement, mining pre -stripping and process ore commissioning . The
resettlement is required to commence mining pre -stripping. Mining pre -stripping is expected to start
approximately five quarters after the final investment decision, in order to provide access to thick, high -grade
zones of the ore body early, and support a short processing plant and production ramp-up.
Figure 5: Assafou Project Construction
Work Stream Q-1 Q-2 Q-3 Q-4 Q-5 Q-6 Q-7 Q-8 Q-9 Q-10 Q-11
Final Investment Decision
Tailings Dam & Water Dams Earthworks
Tailings Dam
Water Storage and Harvest Dam
Construction
Power Supply Construction
Resettlement*
National Road Diversion
Site Infrastructure
Earth Works & Concrete Works
Mining pre-stripping*
Process Plant Construction
Process Plant Commissioning*
First Gold
* Critical path items.
Next steps
• Q2-2026: Procurement of long-lead items has been launched.
• Q2-2026: Detailed engineering and design is underway.
• Q2-2026: EPCM, power and earthworks tender reviews are advancing towards finalisation.
• Q2-2026: Development of the relocation action plan is underway to support the resettlement.
• Q3-2026: Expected completion of mining convention negotiations.
• End-2026: Final investment decision is targeted before the end of 2026.