Overview
Status | Inactive / Suspended |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Mine Life | 4.5 years (as of Jan 1, 2023) |
The combination of the current Edna May underground resource and the Edna May open Stage 3 pit Scoping Study mining inventory representing potentially significant life extension to the Edna May production centre.
As of December 2023, Pre-Feasibility Study work completed. Project deferred due to market volatility. |
Source:
p. 10
Edna May open Stage 3 pit is owned 100% by Ramelius Resources Ltd. subsidiary Edna May Operations Pty Ltd.
Contractors
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Deposit Type
- Metamorphic hosted
- Breccia pipe / Stockwork
- Vein / narrow vein
Summary:
The deposit is well understood geologically. The Edna May Gneiss (EMG) is a metamorphosed tonalitic granitoid within a mafic-ultramafic stratigraphy. It hosts the gold mineralisation which occurs as sheeted quartz, minor sulphide veining, generally parallel to strike and less frequent larger quartz lodes/reefs which cross-cut the gneiss with a more northerly strike and westerly dip. The gneiss strikes east-west (100-120°) and dips at 50-60° to the north. It has a strike length of 1,000m, a width of 50–150m and depth extent of at least 700m. Significant background Au anomalism (0.1 - 0.5 g/t) is present, associated with alteration intensity, proximity to veining and micro-fracturing. Visible gold is frequently seen in drill core in close association with veining and gravity recovery is very high for a low-grade deposit at around 50%.
Hosted by the Edna May Gneiss, a metamorphosed granitoid with strike length of 1km, width of 140m and depth extent of 700m and bounded by a maficultramafic stratigraphy. Mineralisation relates to widespread quartz veining, which occurs as thin sheeted foliation parallel or larger cross-cutting reef veins with a polymetallic sulphide assemblage. Mineralisation forms a broad low-grade stockwork throughout the gneiss. Greenfinch deposit very similar.
Dimensions
Edna May gneiss unit is a lenticular body, typically 50-150m thick, 1000m long and defined down-dip to 700m. It strikes east-west and dips N at 50-60°. Internal high ........
Summary:
The mine Significant historic underground mining occurred between 1911 and 1947. Modern open pit and underground mining has taken place from 1984 to 1998 and then from 2010 to present.
Underground mining will occur concurrently with Stage 3 open pit as far as that is possible. The combination of the current underground resource and the Stage 3 Scoping Study mining inventory representing potentially significant life extension to the Edna May production centre.
Edna May lodes are modelled with consideration of extraction by conventional sub-level open stoping methods and the Edna May model is generated as a bulked, lowgrade model for open pit and bulk underground mining scenarios.
The evaluation shows there is limited interaction with the underground infrastructure during the first 18 months of cutback but some dewatering and electrical infrastructure will need to be relocated.
The next round of evaluations will consider the potential to back-filling of Greenfinch open pit and the Golden Point area to reduce waste movement costs.
Open pit mining methods for open pit resources use 90t rigid dump trucks and excavators of 120 to 200t operating weight. Generally a minimum width of around 3m is assumed for open pit.
Flow Sheet:
Blended ore is processed through 2 stage crushing circuit. Crushed ore is stored on a coarse ore stockpile with a live capacity of approximately 3,800 tonnes. The grinding circuit consists of a primary SAG mill, secondary ball mill crushing circuit.
Primary crushing/grinding plant/machinery:
Mobile crushing fleet including jaw crusher, cone crusher, vibrating screen and 2 x stacker conveyors. 70t and 20t cranes.
Grinding plant equipment:
SAG with 2,000kW installed power, SAG mill size 6.71m x 2.59m, rubber-steel composite liners, Ball mill with 3,720kW installed power, ball mill size 5.03m x 8.21m, composite. Classification WarmanCavex 400mm (400CVX).
Screening plant/equipment:
Trash screen horizontal vibratory 2.4m x 6.1m, polyurethane deck 0.8mm cross flow slots.
Recycle crusher:
Terex RC45 cone crusher, vibrating feeder bypass using an overflow bin. Nominal reduction CCS of 14mm.
Flow Sheet:
Summary:
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Source:
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Projected Production:
Commodity | Units | LOM |
Gold
|
koz
| 266 |
All production numbers are expressed as metal in doré.
Operational Metrics:
Metrics | |
Ore tonnes mined, LOM
| ...... |
Tonnes processed, LOM
| ...... |
* According to 2023 study.
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Reserves at June 30, 2023:
Edna May cut-off grades are +0.5 g/t.
Category | Tonnage | Commodity | Grade | Contained Metal |
Measured
|
720,000 t
|
Gold
|
1.1 g/t
|
25,000 oz
|
Indicated
|
23,000,000 t
|
Gold
|
1 g/t
|
700,000 oz
|
Inferred
|
7,000,000 t
|
Gold
|
1 g/t
|
220,000 oz
|
Total Resource
|
30,000,000 t
|
Gold
|
1 g/t
|
940,000 oz
|
Commodity Production Costs:
| Commodity | Units | Average |
All-in sustaining costs (AISC)
|
Gold
|
AUD
|
......
|
Assumed price
|
Gold
|
AUD
|
......
|
* According to 2023 study / presentation.
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2023 Study Costs and Valuation Metrics :
Metrics | Units | LOM Total |
Initial CapEx
|
$M AUD
|
......
|
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