お知らせ • Jul 18
Centamin plc Announces Positive Doropo Gold Project DFS
Centamin plc provided the outcome of the definitive feasibility study ("DFS") at its Doropo Gold Project ("Doropo") in north-eastern Côte d'Ivoire, including detailed project parameters and economics and an updated Mineral Reserves estimate. Doropo is located in the northeast of Côte d'Ivoire, situated in the north-eastern Bounkani region between the Comoè National Park and the international border with Burkina Faso, 480km north of the capital Abidjan and 50km north of the city of Bouna. The exploration license areas are c.1,847 km2 covering thirteen gold deposits, named Souwa, Nokpa, Chegue Main, Chegue South, Tchouahinin, Kekeda, Han, Enioda, Hinda, Nare, Kilosegui, Attire and Vako. Approximately 85% of the gold deposits are concentrated within a 7km radius ("Main Resource Cluster"), with Vako and Kilosegui deposits located within an approximate 15km and 30km radius, respectively. Geologically, Doropo lies entirely within the Tonalite-Trondhjemite-Granodiorite domain, bounded on the eastern side by the Boromo-Batie greenstone belt, in Burkina Faso, and by the Tehini-Hounde greenstone belt on the west. The DFS is based on the 2023 Mineral Resource Estimate for Doropo published in January 2024. The Mineral Reserve estimate has converted 60% of Mineral Resource ounces to Mineral Reserves. The change in reserve tonnage is primarily due to aligning the reserve gold price applied to Doropo with the Company's long-term gold price of USD 1,450/oz from USD 1,500/oz in the PFS, which reduced the pit shells and designs. However, this impact was offset by an increase in grade, resulting in no change in the total contained ounces. The grade improvement resulted from an improved understanding of the controls of mineralisation following infill drilling programme focused on converting Inferred Mineral Resources to Measured and Indicated Mineral Resources within the resource pit shells, confirming reserve pit depths and initial grade control drilling. There is potential for additional resource conversion and further resource growth. Several exploration targets have been identified across the license holding which have the potential to increase the resource and reserve base. The eight relatively shallow deposits will be mined using a conventional drill, blast, load and haul open pit operation. The basis for the DFS is a contract mining operation, mining a maximum of 28 Mtpa of material and delivering up to 4.9 Mtpa of ore to the run of mine ("ROM") pad and stockpiles annually, with variation based on the location and the combination of oxide, transition and fresh ore mined. The project plans to mine 38Mt of ore to be fed into the process plant and 188Mt of waste over the LOM. The strip ratio has increased from the PFS due to the reduction of some of the upper pit wall angles in the saprolite material near surface, a result of the increased geotechnical study work undertaken. Processing at Doropo will involve primary crushing and grinding of the mined ore, using Semi-Autogenous Grinding ("SAG") mill and ball mill in closed circuit to a target grind size (P80) of 75 microns (µm) for fresh ore and 106 µm for oxide and transition ore. A gravity circuit will recover any native/free gold, before entering the CIL circuit. The gold in the loaded carbon will be recovered by an elution circuit, using electrowinning and gold smelting to produce doré. Flowsheet development was supported by extensive DFS metallurgical test work, supplemented by the PFS results. The DFS metallurgical test work demonstrated a high level of consistency resulting in only minor process design updates from the PFS. The DFS metallurgical test work allowed for extensive optimisation and further simplification of the flowsheet by removing the shear reactor and tailings thickener, while keeping the remaining flowsheet unchanged. The change in recovery was driven by a more conservative calculation method, switching from a grade recovery curve to the use of grade bins split by material type, alongside test work indicating lower recoveries in fresh material. Knight Piésold Consulting carried out a DFS of the site infrastructure for Doropo includingTSF, water storage/harvest dam, airstrip and haul access road. The TSF was designed in accordance with Global Industry Standard on Tailings Management ("GISTM") and Australian National Committee on Large Dams ("ANCOLD") guidelines. The TSF will be fully lined with a geomembrane liner, leachate collection and constructed by the downstream construction method with annual raises to suit storage requirements. The TSF is designed and will be operated as a no discharge facility. The TSF will have a final capacity of 29 million cubic meters (Mm³) or 41 Mt of dry tails. Due to an improved design, it will cover a smaller total footprint area, including the basin area, of approximately 287 hectares ("ha") for the final stage facility, compared to 346 ha in the Preliminary Feasibility Study (PFS). Doropo will utilise the Côte d'Ivoire national grid for its power supply, offering a cost and potential carbon saving relative to other options including self-generation as the tariff benefits from a mix of renewable and thermal generation with a significantportion of hydroelectric power supply. The proposed grid power supply connection for the project is via the existing Bouna substation which is approximately 55km southeast of Doropo. There will also be standby power on-site using diesel generators, for back-up power of critical process equipment and infrastructure if required. Solar power supplementation is currently being investigated to lower grid reliability and overall carbon emissions. The environmental permit for Doropo was granted in June, following public consultation and submission of the Environmental and Social Impact Assessment ("ESIA") in First Quarter 2024. The ESIA was prepared by Earth Systems and H&B Consulting working in conjunction with Centamin. Early development of information has allowed its incorporation into the DFS design and decision-making process. The ESIA shows less than 500 people would require physical resettlement, down from 2,000 to 3,000 in the PFS. Re-alignment of the TSF, water storage dam (WSD), waste rock dumps (WRD) and plant site has reduced the total mine footprint by approximately 25% and reduced impacts on adjacent villages. Overall, 2,000 ha of agricultural land could be impacted by the project development.Mine sequencing will result in a phased approach to land acquisition, compensation and livelihood restoration. Alongside progressive rehabilitation, this will minimise community and physical risks and impacts. The project provides a valuable opportunity to boost local social and economic development with a commitment to invest 0.5% of project revenues into a community development fund. The outer extent of Doropo is 7km from the Comoé National Park, which is a UNESCO World Heritage site.