This technical report documents the mineral processing and metallurgical testwork programs, historical operating performance, and recovery methods for the CMD Gold Mine, located near Andacollo, Chile, with an effective date of 25 September 2014.
Report context
This technical report for the CMD Gold Mine, Andacollo, Chile, was prepared by Geoinvestment on behalf of the mine owner and carries an effective date of 25 September 2014. The report includes sections on mineral processing and metallurgical testing (Section 13) and recovery methods (Section 17), which describe the proposed design basis, historical operating data, and testwork results for the operation as of the effective date.
Processing route
Crushing
The processing route begins with a crushing plant, described in Section 17.1.1 of the report. The crushing plant capacity is reviewed in Section 17.2, which considers the existing equipment and its ability to meet the proposed feed rates. The report provides a design basis for the crushing circuit, though specific equipment details, such as crusher types and settings, are not included in the available sections.
Heap leaching
After crushing, the ore is agglomerated and stacked on a heap leach pad, as described in Section 17.1.2. The heap leaching operation uses a dilute alkaline cyanide solution, which is applied to the top of the heap and allowed to percolate through the ore, dissolving the gold. The pregnant solution is collected at the base of the heap and directed to the ADR plant. The report does not specify the number of heap leach cells, stacking method, or solution application rates.
ADR, EW and smelting
The pregnant solution from the heap leach pad is processed in an ADR (adsorption, desorption, and regeneration) plant, followed by electrowinning (EW) and smelting, as described in Section 17.1.3. The ADR plant recovers gold from the pregnant solution onto activated carbon, then elutes the gold from the carbon using a hot caustic cyanide solution. The gold is then deposited onto steel wool cathodes in electrowinning cells, and the resulting sludge is smelted to produce doré bars. The report does not detail the ADR plant configuration, elution temperatures, or smelting procedures.
Key reported parameters
The following table summarizes key reported parameters from the available sections of the technical report. Design basis values are as proposed in the report, actual values represent historical operating data, and testwork values are from the metallurgical testing programs.
| Parameter | Value | Basis |
|---|---|---|
| Feed rate to crushing plant | Not stated in available sections | Design |
| Crushing plant capacity review | Section 17.2 | Design |
| Gold extraction – cyanidation tests | Not stated in available sections | Testwork |
| Gold extraction – effect of grade | Not stated in available sections | Testwork |
| Gold extraction – ROM leach testwork | Not stated in available sections | Testwork |
| Gold recovery – historical performance | Not stated in available sections | Actual |
| Copper behaviour in leach solution | Section 17.3 | Testwork |
Project website: https://www.cassiusmining.com/
Technical qualifications
The report includes several sections that are relevant to understanding the technical basis for the processing route. Section 13 discusses the metallurgical testing and performance of the plant, including pre-production testwork (Section 13.2.1), historical metallurgical performance (Section 13.2.2), cyanidation tests (Section 13.2.3), the effect of grade on gold extraction (Section 13.2.4), and ROM leach testwork (Section 13.2.5). Section 17 covers the recovery methods in detail, including the processing description (Section 17.1), crushing (17.1.1), heap leaching (17.1.2), ADR/EW/smelting (17.1.3), a review of crushing plant capacity (17.2), and copper behaviour in leach solution (17.3).
The report does not provide quantitative results in the sections reviewed, and specific data tables or figures from the full report are not included here. Design basis values are presented as part of the proposed crushing plant capacity review. Historical operating data are referenced in Section 13.2.2 but not quantified in the available text. Testwork results from cyanidation, grade effect, and ROM leach studies are noted but without numerical values. The report does not provide details on the physical metallurgy or characterization of the ore, and the environmental and permitting aspects are not covered in the sections available.
Source: CMD Gold Mine, Andacollo, Chile Technical Report, effective date 25 September 2014, Sections 13 and 17.
