Caledonia Mining Corporation Plc press release

Endeavour Announces Positive PFS Results for Assafou Project in Côte d'Ivoire

2024-12-11

NYSE - New York Stock Exchange · Jersey

Endeavour Announces Positive PFS Results for Assafou Project in Côte d’Ivoire

ENDEAVOUR ANNOUNCES POSITIVE PFS RESULTS FOR ASSAFOU PROJECT IN CÔTE D’IVOIRE

$1,526m NPV (5%) and IRR of 28% at $2,000/oz • 329kozpa at AISC of $892/oz over first 10 years

| HIGHLIGHTS:

PFS confirms Assafou's potential to become a tier 1 asset for Endeavour PFS highlights 329kozpa production at AISC of $892/oz over first 10 years: 15-year mine life based on maiden reserve of 4.1Moz Robust project economics with after-tax NPV ( 5%) of $1,526m and IRR of 28%, at a $2,000/oz gold price Initial capital of $734m based on a 5Mtpa design nameplate capacity with a similar processing plant configuration as the nearby Lafigué mine

90% resource to reserve conversion with defined maiden reserves of 72.8Mt at 1.76g/t for 4.1Moz Indicated resources of 73.6Mt at 1.95g/t for 4.6Moz based on a drilling cutoff in October 2023, with over 70,000 metres of drilling completed subsequently Further resource expansion and definition at Assafou, and satellite deposits in close proximity to Assafou, is expected to be incorporated into the DFS

Given the high-quality project and attractive economics, the DFS will now commence with completion expected between late 2025 and early 2026 |

Abidjan , 11 December 2024 – Endeavour Mining plc (LSE:EDV, TSX:EDV, OTCQX:EDVMF) (“Endeavour”, the “Group” or the “Company”) is pleased to announce that it has recently completed a positive Pre-Feasibility Study (“PFS”) for the Assafou-Dibibango (“Assafou”) project on the Tanda-Iguela property in Côte d’Ivoire. The PFS results meet Endeavour’s strategic targets and confirm Assafou’s potential to be a tier 1 asset, which justifies advancing the project to the Definitive Feasibility Study (“DFS”) stage.

Ian Cockerill, CEO, commented: “I am delighted with the results of this pre-feasibility study that highlight the potential for Assafou to become a tier 1 asset for Endeavour.

We have defined a large, low-cost and long mine life project, capable of producing 330koz a year over the first ten years, while remaining firmly in the lowest cost quartile. The attractive returns profile ensures this project will remain a capital allocation priority for us and it demonstrates our ability to generate highly value accretive projects, organically, through our pipeline.

Our exploration team discovered Assafou in late 2021, and in less than three years we have defined a high-quality project with close to 5 million ounces of high-grade Indicated resource endowment. We expect that we will continue to grow the Assafou deposit’s resource, and delineate several exciting near-mine targets across the wider Tanda-Iguela property.

Given the excellent project economics, we will now launch the Definitive Feasibility Study and simultaneously advance the permitting process so that we are well positioned to potentially launch construction, with our best-in-class projects team, in the second half of 2026.

With a robust pipeline of organic growth opportunities, we expect to continue to unlock value and deliver long-term production growth towards our 1.5 million ounce target, from a diversified portfolio of assets, by the end of the decade, while maintaining best-in-class margins. This underpins our capital allocation framework, and we expect to continue to deliver supplemental shareholder returns in line with our existing policy, and maintain attractive shareholder returns through this next growth phase.”

Table 1: Assafou Project Highlights

| | | ASSAFOU | STRATEGIC TARGETS | | P&P Reserve, Moz 1 | 4.1 | >2.0 | | | Mine life, years | 14.5 | >10 | | | Average annual production, kozpa | First 10 years | 329 | >200 | | Life of mine | 265 | | | | AISC, $/oz 2 | First 10 years | 892 | Best-in-class | | Life of mine | 936 | | | | Post-tax NPV 5%, $m 2 | 1,526 | n.a. | | | Post-tax IRR, % 2 | 28 | >20 | |

1 Based on a $1,500/oz reserve price. 2 B ased on a gold price of $ 2 , 000 /oz

The key operational and economic highlights of the Assafou PFS are summarised in Tables 2 and 3 below.

Table 2: Assafou PFS Summary

1 Based on a reserves gold price of $1,500/oz and a resource gold price of $1,900/oz 2 Based on a gold price of $2,000/oz 3 GHG Emissions Intensity considers only Scope 1 and 2 emissions

Table 3: Assafou PFS Project Economics

| | | | | | | | Gold Price | $1,500/oz | $1,900/oz | $2,000/oz | $2,500/oz | | | PRE-TAX | | | | | | | NPV 5% , $m | 860 | 1,882 | 2,148 | 3,408 | | | IRR, % | 18 | 31 | 34 | 48 | | | Payback Period, yr 1 | 5.6 | 3.6 | 3.3 | 2.4 | | | AFTER-TAX | | | | | | | NPV 5% , $m | 536 | 1,322 | 1,526 | 2,485 | | | IRR, % | 14 | 25 | 28 | 40 | | | Payback Period, yr 1 | 6.4 | 4.2 | 3.8 | 2.7 | |

1 Payback period 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 PFS within 45 days of this news release.

Overview

The 100% owned Tanda and Iguela permits (“Tanda-Iguela”) are located in the eastern region of Côte d’Ivoire, approximately 600km northeast of Abidjan, adjacent to the Ghana border. The northern permit, Tanda, was added to Endeavour’s portfolio in late 2015 following Endeavour’s transaction with La Mancha. Endeavour conducted an initial drilling campaign in early 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 permitting application process.

Figure 1 : Tanda-Iguela Map

A maiden Indicated resource of 1.1Moz at 2.33 g/t Au was published on 21 November 2022 and was subsequently increased to 4.5Moz at 1.97 g/t Au on 29 November 2023, based on a $1,500/oz gold price.

As shown in Figure 2 below, the PFS demonstrates Assafou’s ability to deliver 329kozpa at AISC of $892/oz over the first ten years of operations, with average production exceeding 350kozpa over an 8-year period once the operation is ramped up, and average production of 265kozpa and AISC of $936/oz over life of mine.

Figure 2: Assafou PFS Production and AISC Profile 1,2

1 Assafou PFS production is based on the 202 4 Mineral Reserve Estimate , and does not incorporate drilling completed after November 2023 , which provides significant upside to the production profile from Y-10 onwards . 2 AISC b a sed on a gold price of $2,000/oz

The PFS production profile is based on the mineral reserves only with an effective date of 31 August 2024, which are constrained by a resource with a drilling cutoff of 31 October 2023. Significant exploration drilling has been completed since this cutoff, which is expected to contribute to resource and reserve upside supporting higher levels of production, particularly in years 10 to 15 of the production profile.

Reserves and Resources

As shown in Table 4 below, the PFS mineral resource is based on the 2023 Mineral Resource Estimate (“MRE”), as published on 29 November 2023, which has been restated using a $1,900/oz gold price, compared to the $1,500/oz gold price used when it was published. The drilling cut-off for the 2023 MRE was 31 October 2023, with the MRE constituting 183,000 metres of drilling at the Assafou deposit. Subsequently, a further 70,000 metres of drilling has been completed during late 2023 and year-to-date 2024 at the Assafou deposit and satellite targets in close proximity to Assafou, which are expected to be incorporated into a future mineral resource update that will underpin the DFS.

Table 4: Assafou Reserves and Resources

| On a 100% basis | | Tonnage | Grade | Content | | (Mt) | (Au g/t) | (Au koz) | | | | Proven Reserves | | - | - | - | | Probable Reserves | | 72.8 | 1.76 | 4,115 | | P&P Reserves | | 72.8 | 1.76 | 4,115 | | Measured Resource (incl. reserves) | | - | - | - | | Indicated Resources (incl. reserves) | | 73.6 | 1.95 | 4,604 | | M&I Resources | | 73.6 | 1.95 | 4,604 | | Inferred Resources | | 3.3 | 1.97 | 208 |

1 Mineral Resource Estimate effective 30 June 2024. Mineral Reserve Estimate effective 31 August 2024. 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 Projects 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 0.5g/ t at a $1,900/oz gold price. Reserves are based on a cut-off grade of 0.4g/t for oxide ore and 0.5g/t for fresh ore and $1,500/oz gold price.

The updated mineral resource estimate for the Assafou deposit comprises an Indicated resource of 73.6Mt at 1.95g/t for 4.6Moz and an Inferred resource of 3.3Mt at 1.97g/t for 0.2Moz, based on a cut-off grade of 0.5 g/t Au and a $1,900/oz gold price. The mineral resource at the Assafou deposit is robust, as it is high-grade and hosted in thick, continuous lenses, as demonstrated by the sensitivity analysis presented in Table 5 below. Inferred material within the pit design was treated as waste in the PFS.

_Table 5: Assafou Mineral Resource Estimate Sensitivity __1 _

| | TONNAGE | GRADE | CONTENT | | | (Mt) | (Au g/t) | (Au koz) | | INDICATED RESOURCE | | | | | Based on a gold price of $1,500/oz | 70.9 | 1.97 | 4,493 | | Based on a gold price of $1,700/oz | 72.7 | 1.95 | 4,560 | | Based on a gold price of $1,900/oz | 73.6 | 1.95 | 4,604 | | Based on a gold price of $2,000/oz | 74.1 | 1.94 | 4,620 | | | | | | | INFERRED RESOURCE | | | | | Based on a gold price of $1,500/oz | 2.9 | 1.91 | 176 | | Based on a gold price of $1,700/oz | 3.2 | 1.98 | 203 | | Based on a gold price of $1,900/oz | 3.3 | 1.97 | 208 | | Based on a gold price of $2,000/oz | 3.4 | 2.01 | 220 |

1 Mineral R esource is estimated effective 30 June 2024 . No Measured resources have been estimated. Minera l Resources estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum ("CIM") definitions standards for mineral resources and have been completed in accordance with the Standards of Disclosure for Mineral Projects 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 are reported undiluted and were constrained by MII $1, 9 00 /oz Pit Shell and for sensitivity purpose by approximate MII at $1, 5 00 /oz and $1, 7 00 /oz and $2,000 /oz pit shells and based on a cut-off of 0.5 g/t Au.

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 mining. The mine planning, resource and cost estimation for the PFS is based on a contract mining operation with a maximum mining capacity of 62.5 Mt per year. 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 life. During the pre-commercial production period approximately 36.5 Mt of pre-stripping is expected to support an accelerated ramp up of the production profile. The DFS 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 away from Assafou.

Diesel excavators and trucks will be used for loading and haulage, with a contractor fleet expected to comprise of 300-tonne and 200-tonne class face excavators to load 140-tonne capacity dump trucks for waste mining, and 200-tonne class excavators to load 140-tonne capacity dump trucks for ore mining.

Processing Operations

Ore will be processed via a 5.0 Mtpa processing plant. Over the life of mine, the plant will be fed with approximately 89% fresh ore and 11% oxide and transitional ore.

Two-stage crushing followed by a high-pressure grinding roll and a ball milling circuit is planned. A primary gyratory crusher will crush ore to a coarse crush size, followed by dual secondary cone crushers. This will feed a crushed ore stockpile that feeds into a high-pressure grinding roll circuit. Ore will then be passed through a conventional ball mill and milled 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 60% is estimated for fresh and oxide/transitional ores at Assafou.

The remaining milled gravity tail will be screened and passed to a carbon-in-leach (“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 and representative metallurgical testwork has indicated that gold is free milling with very high gravity and leach extraction potential, with a projected gold recovery rate of 94% over the life of mine.

Operating Cost Summary

Mining operating cost estimates, prepared by Endeavour, are based on a contractor mining model. Process operating cost estimates were prepared by Lycopodium, who have successfully supported Endeavour through five engineering and construction projects in West Africa over the last ten years. General and Administration (“G&A”) cost estimates were also prepared by Lycopodium with input from Endeavour, as summarised in the table below.

Table 6: Assafou Life of Mine Operating Unit Costs (-15/+20%)

Based on estimates that exclude escalation

Operating costs have been based on a delivered diesel price of $0.92 per litre and are in line with current local pricing. Power will be sourced from the grid supplying 90kV to site via a ring main system providing power from two different sources of transmission to increase reliability, with power costs estimated at $0.16/kWh.

Capital Cost and Infrastructure Summary

The project capital cost estimate was compiled by Lycopodium with input from Knight Piésold on the TSF, water infrastructure, site access roads and airstrip, from Digby Wells on relocation, and from ECG Engineering on the power infrastructure. Endeavour has provided project specific estimates for mine establishment, facilities and owner’s costs.

The initial capital cost is summarized in the table below.

_Table 7 : Assafou Upfront Capital Cost Estimate Summary (-20/+25%) _

| | CAPITAL COSTS (US$M) | | Mining | 156.3 | | Treatment Plant Costs | 115.5 | | Reagents and Plant Services | 34.9 | | Site Infrastructure | 109.2 | | Offsite Infrastructure | 79.7 | | Contractor Distributables | 36.6 | | Indirect Costs | 120.3 | | Subtotal | 652.5 | | Contingency | 79.0 | | Taxes and Duties | 2.7 | | Total Upfront Capital Cost | 734.2 |

Based on estimates that exclude escalation

The Assafou project capital cost estimate assumes a contractor mining model, selected due to the lower upfront capital costs and the additional fleet flexibility that can accommodate the pre-production mining ramp-up. Within the subsequent DFS, a hybrid approach to contract and owner mining may be considered to ensure capital and operating costs are optimised, while the mining ramp-up is de-risked.

The Assafou project benefits from good surrounding infrastructure, including access to the 90kV power supply within 14km of the project, and access to the A1 national road, which will be diverted around the operation and provide access to the operation. An airstrip will be built 3.5km from the permanent accommodation. Resettlement of two villages within close proximity to the project is required and is included in the capital cost estimate.

The tailings storage facility (“TSF”) is expected to be a 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 252ha for the stage 1 TSF to 278ha 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 73Mt of tailings, with the potential to be expanded to 110Mt. 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.

The recommendations from the Environmental Social Impact Assessment (“ESIA”) which is underway, will be used to compile an Environmental and Social Management Plan (“ESMP”) which will guide Endeavour’s local community engagement as well as ensuring it fulfils its environment obligations, minimising the mine’s impacts where possible. The ESMP will be used to monitor and ensure compliance with environmental specifications, monitoring and management measures and will be implemented from site preparation through to decommissioning and closure.

Figure 3 below highlights the proposed site and infrastructure layout.

Figure 3: Assafou Schematic Site Layout

Ownership, Permitting, Taxes and Royalties

Endeavour acquired the Tanda exploration permit in 2015, subsequently acquiring the Iguela permit, which contains the Assafou project, in 2017. Endeavour will retain full ownership of the Tanda-Iguela permits until the permits are converted into an exploitation permit. Based on the current 2014 Mining Convention, once the exploitation permit is granted, Endeavour will be entitled to an 80% stake in the Assafou project, while SODEMI (the Ivorian state-owned mining company) and the Government of Côte d’Ivoire will each have a 10% stake.

A corporate tax rate of 25% of gross profit has been applied in the PFS. A royalty of 5.0% and a community levy royalty of 0.5% was applied to all sales. Gold royalties in Côte d’Ivoire are based on a sliding scale with the gold price, and vary between 3.0% and 6.0%. A transport and refining charge of $4/oz Au was also applied.

The mining code is currently under review and if the proposed new mining code is passed into law before the Assafou exploration permit is converted into an exploitation permit, then the fiscal terms applicable to the Assafou project are expected to reflect those of the new mining code. If the new mining code is passed into law in its current draft state, it is expected to include an increase in the Governments free-carried interest from 10% to 15%. This would result in Endeavour’s potential stake in the Assafou project, once the exploration permit has been converted into an exploitation permit, decreasing from 80% to 75%.

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