Bibemi Gold Project Metallurgical Testwork Update

The information contained within this announcement is deemed to constitute inside information as stipulated under the retained EU law version of the Market Abuse Regulation (EU) No. 596/2014 (the "UK MAR") which is part of UK law by virtue of the European Union (Withdrawal) Act 2018. The information is disclosed in accordance with the Company's obligations under Article 17 of the UK MAR.  Upon the publication of this announcement, this inside information is now considered to be in the public domain.

Oriole Resources PLC

(“Oriole Resources” or the “Company”)

Bibemi Gold Project - Metallurgical Testwork Update

Oriole Resources (AIM:ORR), the AIM quoted exploration and development company focused on Central and West Africa, is pleased to announce an update on its 50% owned Bibemi gold project (“Bibemi” or the “Project”) in north-eastern Cameroon, where the Company is in the process of negotiating an Exploitation Licence for a small-scale open pit gold mine.  The Company has now received the results of metallurgical testwork undertaken by ALS Ltd. Australia (“ALS”) on bulk oxide and sulphide samples from the Project.

Highlights

·           The bulk oxide sample results replicated prior testwork undertaken on smaller samples, confirming that the material is amenable to cyanidation, with >90% gold recovery after 24 hours of leaching.

·           Testwork on the two bulk sulphide samples focused on ultra-fine grinding of the flotation concentrate as a route to potentially replacing the pressure oxidation (“POX”) assumed by the current Preliminary Economic Assessment (“PEA”).  Results indicate that:

-          Flotation of sulphide samples returned approximately 80% Au at a coarse grind size (75 microns, “μm”), therefore similar to previous testwork; and

-          Ultra-fine grinding (to 20μm and 10μm) and subsequent leaching of the flotation concentrate has resulted in downstream gold recoveries of between 94 and 98%.

• Overall, gold recovery for the ultra-fine grind flowsheet is broadly comparable with the assumptions in the current PEA, giving a viable alternative that has the following benefits:

-          Simplification of the process plant leading to faster project execution, commissioning and ramp-up;

-          A reduction in the level of management and supervisory skills required to operate and maintain the plant;

-          Elimination of equipment operating at high pressure which reduces safety risk; and

-          Elimination of the need for specialised autoclave construction materials that would have been required for the Project given its small size.

Stirling Process Engineering Ltd (“Stirling”) is currently engaged in generating a more detailed understanding of the capital and operating costs in a report related to this flowsheet to enable the production of an updated PEA which will include this alternative process route as an option.  This updated PEA is anticipated later this quarter.

Chief Executive Officer of Oriole Resources, Martin Rosser, said: “We welcome the latest Bibemi mineral processing test results as there is now encouraging potential for an improved flowsheet as an alternative to the earlier one developed using pressure oxidation.  As such, the provisional indication is that capital and operating costs will likely be comparable, with significant operational benefits, thus confirming ultra-fine grinding as a viable alternative.  We look forward to receiving Stirling’s detailed trade-off study.

“Having the option of a processing flowsheet that uses ultra-fine grinding gives processing method flexibility compared to one using POX.  Both methods will have pros and cons for the processing of other gold-telluride deposits that may occur in Cameroon, dependent upon the magnitude of plant throughput and ore mineralogy.”

Further Details

At the 177km2 Bibemi orogenic gold project in the North region of Cameroon, the Company's exploration to date has identified shear-hosted gold mineralisation at four main prospects - Bakassi Zone 1, Bakassi Zone 2, Lawa West and Lawa East - within an approximately 12km long mineralised hydrothermal system at surface.

The Project has a Mineral Resource Estimate (“MRE”) of 6.96Mt at 2.06g/t Au for 460koz contained Au, 100koz Au of which is classified as Indicated, and the remaining classified as Inferred under the JORC Code.  The MRE, which is located entirely within the BZ1-MRE zone, is calculated using a 0.40g/t Au cut-off grade and is constrained by a US$2,750/oz gold price pit shell (see announcement dated 15 May 2025).  In addition to the MRE, the Company has also reported an Exploration Target across the Bibemi project of between 3.0 and 5.0Mt with an average grade of between 1.50 and 2.50g/t Au, for between 145 and 400koz contained gold.

The Company has submitted an Exploitation Licence Application (“ELA”) for the Project, which is envisaged to be a small-scale, open pit mine that would target an optimised open-pit scenario of 89koz Au, largely centred on the 100koz Au Indicated Resource.  As part of the ELA a PEA of this optimised scenario, assuming a 7-year mine life, at ~10koz Au average annual production, was included within the ELA (see announcement dated 16 December 2025), and is considered to be at Scoping Study level.

The PEA also assumed an 85% gold recovery which reflected results from prior metallurgical testwork on sulphide material, at SGS South Africa between 2022 and 2024, that outlined a provisional mineral processing flowsheet to treat the gold-telluride mineralogy, comprising flotation, pressure oxidation of the float concentrate, and leaching of the pressure oxidation residue (see announcement dated 15 May 2025).

The Company today reports that it has recently completed follow-up metallurgical testwork at ALS Perth, using two shallow, near-surface oxide samples, and two sulphide samples.  The testwork included initial characterisation of the oxide material and a subsequent, more detailed study on the sulphide material.  The latter focused on ultra-fine grinding of the flotation concentrate as a route to potentially replace the existing POX circuit.

The results of this testwork have confirmed that the two oxide samples were amenable to conventional cyanidation with recoveries of more than 90% after 24 hours of leaching using a 75μm grind.  Flotation testwork on the two sulphide samples, when subjected to a 75μm grind, returned 81% and 82% Au respectively after 24 hours cyanidation.  Both sets of results are comparable with the prior SGS results.  Further testwork was then completed on the flotation concentrate, ultrafine grinding it to 20μm and 10μm size fractions with subsequent cyanidation.  The downstream gold recoveries were between 94 and 98% after 72 hours (therefore 94-98% of the 81-82%). 

Figure 1. Updated provisional Processing Flowsheet for the Bibemi Project

Overall, gold recovery for the ultra-fine grind flowsheet is broadly comparable with the former POX flowsheet.  However, it has the following key benefits over the pressure oxidation flowsheet, including:

-          Simplification of the process plant leading to faster project execution, commissioning and ramp-up;

-          A reduction in the level of management and supervisory skills required to operate and maintain the plant;

-          Elimination of equipment operating at high pressure which reduces safety risk; and

-          Elimination of the need for specialised autoclave construction materials that would have been required for the project given its small size.

Stirling is now completing a trade-off study for the different options.  The provisional indication is that capital and operating costs, which will be included as an option in an updated PEA, will likely be comparable thus confirming ultra-fine grinding as a viable alternative.  This updated PEA is anticipated later this quarter.

For further information on Bibemi, including maps and a JORC Table 1, please see the following page of the Company's website https://orioleresources.com/projects/bibemi/.

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Glossary and Abbreviations

Notes to Editors

Oriole Resources PLC is an AIM-quoted gold exploration and development company, with projects in Central and West Africa.  It is currently focused on projects in Cameroon.

At its district scale Central Licence Package (CLP) in Cameroon, the Company has identified multi-kilometre long gold anomalies, including at its flagship Mbe project.  At Mbe, the Company has published a global JORC Inferred MRE of 1.66Moz contained gold at MB01, consisting of 1.30Moz at 1.01g/t Au for the MB01-S deposit, and 360koz at 1.05g/t Au for the MB01-N deposit.  Following the completion of the MB01-N drilling programme, and by meeting various financial commitments, BCM International (“BCM”) has earned a 50% interest in the Mbe project, and Oriole has recently completed a corporate restructuring to confirm the Company's and BCM's respective 50% interest in Mbe.  Drafting of a JV partnership agreement is nearing completion.

The Company has also reported a Resource of 460,000oz contained gold at 2.06g/t Au in the JORC Indicated and Inferred categories at its 50% owned Bibemi project in Cameroon, where it has applied for an Exploitation Licence.  In November 2025, BCM completed its earn-in to give it a 50% interest in Bibemi by meeting certain payment conditions, including spending US$4 million on exploration.  

At its 85%-owned Wapouzé limestone project in north-eastern Cameroon, the Company has recently published a maiden JORC Inferred Resource of 32.2Mt with weighted average grades of 50.33wt% CaO, 1.13wt% MgO and 6.06wt% SiO₂.  Outside of the MRE, an Exploration Target of between 5.5 and 14.0Mt of marble with weighted average grades of between 48 and 53wt% CaO and 0.8 and 1.4wt% MgO.  The Company has also recently announced the submission of an ELA and ESIA for the project and is ultimately looking to achieve an income that could be used as additional funding for Oriole's gold-focused exploration work in Cameroon.

At the Senala gold project in Senegal, AGEM Senegal Exploration Suarl (“AGEM”), a wholly owned subsidiary of Managem Group, has completed a six-year earn-in to acquire an approximate 59% beneficial interest in the Senala Exploration Licence by spending US$5.8 million.  The Company has reported a Resource of 155,000oz contained gold at 1.26g/t Au (using a gold price of US$1,800/oz) in the JORC Inferred category for the Faré South prospect, and an additional, complementary Exploration Target range of 17Mt to 24Mt at a grade of 0.69g/t to 0.84g/t Au for 380,000oz to 650,000oz contained gold for all prospects at Senala.  Best results to date include 20.00m grading 31.13 g/t Au including 10.00m grading 60.98 g/t Au from RC drilling and 59.60m grading 2.20 g/t Au from diamond drilling.  A JV agreement was signed in July 2026 with a US$2 million work programme planned for the current field season.

The Company also has several interests in companies operating in East Africa and Turkey that could give future cash payments.

For further information please visit www.orioleresources.com, @OrioleResources on X