This report presents the definitive feasibility study for the Lafigué gold project in Côte d'Ivoire, including a proposed processing plant design based on extensive metallurgical testwork.
Report context
The Lafigué Project NI 43-101 Technical Report, with an effective date of 1 June 2022 and publication date of 30 November 2022, was prepared by Lycopodium Ltd for Endeavour Mining plc. The report documents the results of a Definitive Feasibility Study (DFS) for the Lafigué gold project located in Côte d'Ivoire.
Processing route
Overview of processing approach
The proposed processing route for the Lafigué Project is a conventional gold recovery flowsheet comprising comminution, gravity concentration, and carbon-in-leach (CIL) cyanidation. The process design is based on metallurgical testwork programs conducted in 2018, 2019, and 2021, as documented in Section 13 of the technical report.
Comminution circuit
The comminution circuit is designed with a primary crushing stage feeding a crushed ore stockpile, followed by high-pressure grinding rolls (HPGR) crushing and wet screening. The HPGR product reports to a grinding and classification circuit. This circuit selection was informed by comminution testwork programs conducted across the three testwork phases, which included scouting testwork in 2018 and more detailed programs in 2019 and 2021.
Gravity concentration
The flowsheet includes a gravity circuit positioned between the grinding circuit and the leach circuit. The gravity circuit processes a portion of the cyclone underflow to recover free gold prior to leaching. Bulk gravity gold separation testwork was conducted on master composites as part of the 2019 programme to support this design.
Leach and adsorption
After gravity recovery, the slurry reports to trash screening and pre-leach thickening before entering the leach/adsorption circuit. The proposed design uses a CIL circuit for gold leaching and adsorption onto activated carbon. Leach optimisation testwork was completed on master composites from both the 2019 and 2021 programmes, examining parameters such as grind size, cyanide concentration, and residence time. Variability testwork was also conducted across multiple composite samples representing different ore types and weathering zones.
Elution and gold recovery
Loaded carbon from the CIL circuit is processed through an elution circuit and goldroom operations for gold recovery and bullion production.
Tailings disposal
Tailings from the leach circuit are directed to a tailings storage facility, as described in the project infrastructure section. Cyanide detoxification testwork was performed to inform tailings management design.
Reagent and consumable requirements
The report provides annual reagent and consumable requirements for the proposed plant, based on testwork results indicating expected consumption rates for cyanide, lime, and other reagents.
Key reported parameters
| Parameter | Value | Basis |
|---|---|---|
| Process plant design throughput | Not specified in processing sections | DFS design basis |
| Crushing stage | Primary crushing | Proposed design |
| Secondary/tertiary crushing | HPGR with wet screening | Proposed design |
| Grinding circuit | Ball mill with classification | Proposed design |
| Gravity circuit | Included, cyclone underflow feed | Proposed design |
| Leach circuit | Carbon-in-leach (CIL) | Proposed design |
| Gold recovery method | Gravity + CIL cyanidation | Proposed design |
| Testwork programs | 2018, 2019, 2021 | Historical testwork |
| Master composite testwork | 2019 and 2021 programmes | Completed testwork |
| Variability testwork | Multiple composites, 2019 and 2021 | Completed testwork |
| Comminution testwork | Scouting (2018), programmes (2019, 2021) | Completed testwork |
| Grind optimisation | Master composites | Testwork completed |
| Leach optimisation | Master composites, 2019 and 2021 | Testwork completed |
| Oxygen uptake rate tests | Performed | Engineering design parameter testwork |
| Rheology tests | Performed | Engineering design parameter testwork |
| Carbon adsorption tests | Performed | Engineering design parameter testwork |
| Cyanide detoxification tests | Performed | Engineering design parameter testwork |
| Thickening testwork | Performed | Engineering design parameter testwork |
| Preg-robbing assessment | Completed, 2019 programme | Testwork completed |
| Heap leach amenability testing | Completed, 2019 programme | Testwork completed |
Project website: https://www.endeavourmining.com/our-portfolio/lafigue-mine/
Technical qualifications
The processing route described in this report is a proposed design based on definitive feasibility study level engineering. All metallurgical testwork results reported are from laboratory-scale programs; no pilot plant or commercial-scale production data from the Lafigué deposit are available. The report does not provide final achieved gold recovery values, final reagent consumption rates, or final process plant throughput capacity in the processing sections excerpted for this article. The report does not contain historical operating data from mining at Lafigué, as no prior production history exists for this project. Capital and operating cost estimates, economic analysis, and project implementation schedules are documented in separate sections of the technical report but are not included in the processing sections provided.
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*Source: Lafigué Project, Côte d'Ivoire, NI 43-101 Technical Report, Definitive Feasibility Study (DFS), effective date 1 June 2022, publication date 30 November 2022, Sections 13 (Mineral Processing and Metallurgical Testing) and 17 (Recovery Methods).*
