Overview
| Stage | Construction |
| Mine Type | Underground |
| Commodities |
|
| Mining Method |
- Sub-level open stoping (SLOS)
- Paste backfill
|
| Production Start | ...  |
| Mine Life | 17 years (as of Jan 1, 2021) |
The development of the Underground Mine will enable Cowal’s production to grow to a goal of 350,000 ounces of low-cost gold a year and extend its mine life to 2040. The Underground Mine will provide a higher-grade ore source that will be blended with the current E42 open pit and stockpile ore.
Cowal achieved significant milestones during the year with the Board and regulatory approvals to commence construction of the new Underground mine adjacent to the existing E42 open pit. The project has now awarded all material contracts and remains on budget and schedule for critical path items, with first stope ore planned for Q4 FY23. The waste strip of Stage H completed in Q1 FY22 which has enabled the operation to access higher grade ore. Construction of the Integrated Waste Landform continued as planned to provide tailings capacity to support the life of mine. |
Source:
p. 17
| Company | Interest | Ownership |
|
Evolution Mining Ltd.
|
100 %
|
Indirect
|
|
Evolution Mining (Cowal) Pty Ltd.
(operator)
|
100 %
|
Direct
|
The Cowal Mine tenement incorporates seven contiguous exploration licences (EL) and two ML covering 1073 km2. All leases are 100% held by Evolution. Evolution operates wholly-owned mine - Cowal in New South Wales.
Contractors
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Deposit Type
- Vein / narrow vein
- Epithermal
- Mesothermal
Summary:
The gold deposits, E42, E41, E46 and GRE46 are structurally hosted, epithermal to mesothermal gold deposits occurring within and marginal to a >500m thick dioritic to gabbroic intrusion (Muddy Lake Diorite) doming the stratigraphically upright andesitic and dacitic volcaniclastic rocks and lavas.
Gold mineralisation is associated predominantly with extensional, dilatant and shear quartz-carbonate veining with pyrite and a later base metal assemblage consisting of sphalerite, chalcopyrite, and galena. Visible gold is often associated with this base metal event.
Geology of the GRE46 prospect is controlled by the north to south striking Glenfiddich Fault which separates the moderate north-west dipping Cowal mine sequence of trachydacitic lavas, volcaniclastic mudstones and diorite on the western side from andesitic lava, various mass flow conglomerate units, mudstones and diorite on the East. Bedding changes sharply on the East of the Glenfiddich with GRE46 units steeply dipping to the west. Bedding remains upright younging to the west.
Mineralisation at the GRE46 underground deposit is structurally controlled and is intimately associated with logged or mapped structures. A complex geometry of E-W striking, sub-horizontal extensional veins, moderate south dipping shear extensions and steep south dipping colloform and laminated veins are present at the GRE46 deposit. The three main structures affecting mineralisation at GRE46 are the Glenfiddich F ........
Mining Methods
- Sub-level open stoping (SLOS)
- Paste backfill
Summary:
Mining method assessments indicated that sub-level open stoping (SLOS) with pastefill was the most appropriate mining method for the GRE46 underground deposit.
Access to the orebody will be via a decline positioned on the hangingwall (HW) in the upper section of the Galway and Endeavor orebodies and from the Footwall (FW) for Dalwhinnie and Regal orebodies. The stope extraction sequence is a combination of longitudinal and transverse stope extraction. Grade control infill drilling will be required prior to production related activity. Infill drilling commenced in June 2021 targeting a spacing of 20 m by 20 m and with second pass drilling to 10 m by 10 m as required. All stope voids are to be backfilled with pastefill.
Mining recoveries were set at 100% for development activities, and 95% for stoping activities.
All material mined underground will be trucked to surface to the Run of Mine (ROM) pad or waste dump.
The development of the Cowal Underground Mine is progressing well and is on budget and schedule. Approximately 6,450 metres of underground development has been completed to 30 June 2022 and first production ore is on schedule for the June 2023 quarter.
Source:
- subscription is required.
Flow Sheet:
Summary:
- subscription is required.
Projected Production:
| Commodity | Units | Avg. Annual | LOM |
|
Gold
|
koz
| 350 | 1,700 |
All production numbers are expressed as metal in doré.
Operational Metrics:
| Metrics | |
|
Annual ore mining rate
| ...... |
* According to 2021 study.
- Subscription is required.
Reserves at December 31, 2021:
Mineral Resource cut-off - 1.5 g/t.
Ore Reserve cut-off - 1.8 g/t.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Probable
|
14.4 Mt
|
Gold
|
2.31 g/t
|
1,069 koz
|
|
Indicated
|
22.4 Mt
|
Gold
|
2.47 g/t
|
1,776 koz
|
|
Inferred
|
13.3 Mt
|
Gold
|
2.32 g/t
|
991 koz
|
|
Total Resource
|
35.7 Mt
|
Gold
|
2.41 g/t
|
2,766 koz
|
Commodity Production Costs:
| | Commodity | Units | Average |
|
Assumed price
|
Gold
|
AUD
|
...... &nbs
|
* According to 2021 study / presentation.
- Subscription is required.
Operating Costs:
| | Units | 2021 |
|
UG mining costs ($/t mined)
|
AUD
| 75 * |
|
Processing costs ($/t milled)
|
AUD
| ...... |
* According to 2021 study. Average cost.
- Subscription is required.
2021 Study Costs and Valuation Metrics :
| Metrics | Units | LOM Total |
|
Pre-Production capital costs
|
$M AUD
|
......
|
|
Pre-tax IRR, %
|
|
......
|
|
Pre-tax payback period, years
|
|
......
|
- Subscription is required.
- Subscription is required.