This report documents the 2011 prefeasibility study for the Esaase Gold Project in Ghana, detailing the proposed mineral processing flowsheet and supporting metallurgical testwork.
Report context
The Esaase Gold Project technical report, dated 4 November 2011, was prepared by Coffey Mining Pty Ltd as a National Instrument 43-101 compliant technical report. The report presents the results of a September 2011 prefeasibility study, including metallurgical testwork and a proposed process plant design. The project was at an advanced stage of evaluation, with both open pit mining and processing considered in the study.
Processing route
Testwork History
Metallurgical testing for the Esaase Gold Project was conducted over multiple phases leading up to the September 2011 prefeasibility study. The testing programme included mineralogical characterisation and metallurgical testwork, with the results forming the basis for the process flowsheet design presented in this report.
Mineralogy
The gold mineralisation at Esaase is described in the report through dedicated mineralogical studies that supported the metallurgical testwork. These studies provided essential information on the deportment of gold and associated sulphide minerals that guided the selection of the processing route, although the specific mineralogical compositions of the ore types are not described in the sections of the report provided.
Metallurgical Testwork
Metallurgical testwork was undertaken as part of the project evaluation and is documented in the report under Section 13.1.3. The testwork programme was designed to assess the process response of the Esaase ore to the proposed flowsheet. The specific results of this testwork are not detailed in the extracted report sections provided, but they contributed to the metallurgical design criteria used for the prefeasibility study.
Process Flowsheet
The proposed process flowsheet for the Esaase Gold Project, as presented in the September 2011 prefeasibility study, incorporates the following unit operations:
- Primary ore crushing followed by stockpiling
- Grinding and classification
- Gravity concentration
- Rougher spiral circuit
- Concentrate regrind
- Pre-leach thickening
- Carbon in leach (CIL) for gold recovery
- Carbon elution and gold recovery
- Cyanide detoxification
The complete process plant design is described in Section 17 of the report, from which the above unit operations were identified.
Key reported parameters
| Parameter | Unit | Reported Value | Basis |
|---|---|---|---|
| Project name | , | Esaase Gold Project | , |
| Study date | , | September 2011 | Prefeasibility study |
| Report date | , | 4 November 2011 | , |
| Process throughput | , | Not reported in provided sections | , |
| Gold recovery | , | Not reported in provided sections | , |
| Ore feed grade | , | Not reported in provided sections | , |
| Mine life | , | Not reported in provided sections | , |
| Grinding | , | SAG/Ball mill circuit (assumed from text) | Proposed design |
| Gravity circuit | , | Included | Proposed design |
| Flotation | , | Not explicitly stated; spiral circuit proposed | Proposed design |
| Leaching | , | Carbon in leach | Proposed design |
| Crushing | , | Primary crushing to stockpile | Proposed design |
Technical qualifications
The following limitations apply to the processing information provided in the report:
- The report does not provide detailed throughput, recovery, or production rate figures in the sections extracted, meaning such data is not available for presentation.
- The full metallurgical testwork results are not described in the sections of the report provided for this summary, and therefore the readers are referred to the full technical report for these details.
- The process flowsheet design is presented as proposed for the September 2011 prefeasibility study and does not show historical plant operating data, as no such data exists for this project.
- The report does not provide specific equipment sizing, power consumption, or reagent consumption data in the sections examined.
- Information on the historical operating performance of processing circuits at this site is not applicable, as the project had not been constructed at the date of the report.
Source: Esaase Gold Project, Ghana, 43-101 Technical Report, 4 November 2011.
