This technical report describes the mineral processing facilities and metallurgical testwork for the Lefa Gold Project in Guinea, as of September 2012.
Report context
This NI 43-101 technical report for the Lefa Gold Project, Guinea, is dated September 2012 and prepared for Nord Gold N.V. The report covers project history, geology, mineral resources and reserves, mining methods, mineral processing, and economic analysis. This article focuses on the processing route, metallurgical testwork, and recovery methods described in the report.
Processing route
Existing Process Plant
The Lefa Gold Project operates a conventional carbon-in-pulp (CIP) processing plant. The process description is based on the existing plant design and historical operating data. Run-of-mine ore is delivered to a stockpile and then fed via the Lero Karta conveyor to the crushing plant. The crushing plant reduces ore size prior to grinding. Grinding is conducted in a mill circuit. Following grinding, the slurry reports to the CIP plant where gold is recovered by adsorption onto activated carbon. The plant includes an assay laboratory for process control and plant sampling. Process water is supplied to the plant, and tailings are deposited in a tailings facility. Reagent storage facilities support plant operations.
Historical Metallurgical Testwork
Historical metallurgical testwork conducted prior to 2012 included mineralogy studies, comminution testing, and beneficiation testwork. The mineralogy of the ore was characterised. Comminution tests evaluated the grinding characteristics of the ore. Beneficiation testwork investigated gravity separation and other recovery methods.
Metallurgical Testwork in 2012
Metallurgical testwork was performed in 2012 on samples from the Banora and Fayalala deposits. The testwork followed defined procedures. Results and discussion are presented for both deposits separately. For Banora, specific metallurgical conclusions were drawn. For Fayalala, separate conclusions were provided.
Heap Leach Processing
The report describes a heap leach processing option as part of future development considerations. The heap leach facility is separate from the main CIP plant.
Future Development
The report includes a section on future development, which discusses potential modifications or expansions to the processing facilities. No specific design details are provided beyond those described for the existing plant.
Tailings Facility
The tailings facility receives tailings from the CIP plant. The facility is described in the process description section of the report.
Key reported parameters
| Parameter | Unit | Design/Actual/Testwork Basis | Value |
|---|---|---|---|
| Processing method | , | Design/Actual | Carbon-in-pulp (CIP) |
| Crushing plant | , | Design/Actual | Conventional crushing circuit |
| Grinding mill | , | Design/Actual | Mill circuit |
| Gold recovery method | , | Design/Actual | Carbon adsorption |
| Metallurgical testwork | , | Testwork 2012 | Banora and Fayalala deposits |
| Heap leach | , | Design option | Separate facility |
| Tailings facility | , | Design/Actual | Conventional tailings storage |
Project website: https://nordgold.com/operations/
Technical qualifications
The report presents mineral processing information based on the existing plant design and historical operating data. Metallurgical testwork results are provided for specific deposits only. The report does not include detailed flowsheet diagrams, equipment specifications, or plant performance data beyond what is summarised. Future development plans are discussed but not fully detailed. No economic analysis of processing options is included in the processing sections.
Source: Nord Gold N.V, The Lefa Gold Project, Guinea, NI 43-101 Technical Report, September 2012, Sections 1.11, 13, and 17.
