Overview
Stage | Permitting |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Cut & Fill
- Sub-level open stoping (SLOS)
- Cemented (undefined) backfill
- Undefined backfill
|
Mine Life | 7 years (as of Jan 1, 2022) |
Blue Spec is one of several Calidus expansion plans for Warrawoona mine.
Blue Spec is a steeply dipping vertical/sub-vertical narrow vein deposit. Maiden Blue Spec Reserve underpins expansion for Warrawoona . There are two separate mining areas located ~1.2 km apart along strike, named Blue Spec and Gold Spec. The Sulphide Plant would be constructed at Warrawoona with Blue Spec and Copenhagen ore trucked to Warrawoona for processing.
Permitting for Blue Spec is progressing. On 11 September 2023, Calidus announced the final approval had been received to commence mining the Blue Spec project. |
Source:
p. 9
Calidus Resources is an ASX listed gold company that owns 100% of the operating 1.4Moz Warrawoona Gold Project.
Contractors
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Deposit Type
- Orogenic
- Vein / narrow vein
Summary:
The Blue Spec gold project lies within the Mosquito Creek Formation, a thick sequence of siliciclastic metasediments comprising dominantly quartz-rich arenites and shales that has undergone multiple periods of deformation. The Mosquito Creek Formation is located within the extensive rhombic Mosquito Creek Basin in the southeastern extent of the Pilbara granite-greenstone terrane (Easterday et al., 2008). The Mosquito Creek Formation is interpreted to be Mesoarchaean in age (Bagas et al., 2008).
Stratigraphy within the basin generally trends east–northeast, with both northwest and north–south trending regional fault orientations exerting major influences on the basin architecture. Intrusive dykes comprising dolerite and hornblende-bearing tonalities are also observed within the basin, while gabbroic sills are a prominent feature along the northern and southern margins of the basin. The Blue Spec line is a clearly defined and mapped, major fault structure that nucleated during north–south oriented regional shortening, upright folding and thrusting along a major anticlinal hinge position. It has undergone multiple periods of deformation (Easterday et al., 2008).
The Blue Spec Shear gold-antimony deposits are interpreted to be epizonal orogenic gold deposits. Gold mineralisation is associated with the Blue Spec Shear Zone that was emplaced during two deformation events. The first event produced a laminated quartz-carbonate vein with minor pyrite, gold and ar ........
Mining Methods
- Cut & Fill
- Sub-level open stoping (SLOS)
- Cemented (undefined) backfill
- Undefined backfill
Summary:
Blue Spec is a steeply dipping vertical/sub-vertical narrow vein deposit. There are two separate mining areas located ~1.2 km apart along strike, named Blue Spec and Gold Spec. Detailed analysis by independent geotechnical experts Peter O’Bryan & Associates was carried out to Feasibility study standard and this provided the key justification for the chosen mining method.
The assumed mining method is sub-level open stoping (SLOS) with cemented rock fill (CRF) and a minimum mining width of 3.5 m.
Based on these inputs, the mining method selected was overhand mechanised cut-and-fill with four x 4mH lifts in each panel (total panel height 16m). Three lifts will be extracted using jumbo development techniques with the top lift finally back-stripped on retreat. Cemented rockfill (CRF) will be placed in the bottom lift to allow stoping underneath, with uncemented rockfill used elsewhere. Single-boom jumbo drills will be used for the ore development and low-profile loaders for production material movement.
ccess to the mine is planned to be through a boxcut and portal arrangement, via a 5.0 mW x 5.0 mH decline. Capital development will be mined using twin-boom jumbos and 5 m3 loaders, which will also load all material onto trucks.
A minimum mining width of 2.5 mW was applied to ore development and jumbo stripping. Unplanned dilution and mining recoveries were applied based on the lift sequence as follows:
1. Bottom drive - no dilution ........
Source:
Source:
Summary:
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Source:
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Projected Production:
Commodity | Units | LOM |
Gold
|
oz
| 154,644 |
All production numbers are expressed as payable metal.
Operational Metrics:
Metrics | |
Annual processing rate
| ...... |
* According to 2022 study.
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Reserves at June 30, 2022:
Mineral Resources for Blue Spec were calculated on a cut-off of $240/t using Net smelter return.
Ore Reserve: A stoping cut-off value of $141/t ore and a development ore cut-off value of $45/t ore has been applied based on the NSR inputs and relevant cost estimates from previous studies on the project.
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
230 kt
|
Gold
|
11.2 g/t
|
83 koz
|
Indicated
|
94 kt
|
Gold
|
31.1 g/t
|
95 koz
|
Indicated
|
94 kt
|
Gold Equivalent
|
35.7 g/t
|
108 koz
|
Inferred
|
148 kt
|
Gold
|
20.1 g/t
|
96 koz
|
Inferred
|
148 kt
|
Gold Equivalent
|
23.8 g/t
|
114 koz
|
Total Resource
|
243 kt
|
Gold
|
24.4 g/t
|
190 koz
|
Total Resource
|
242 kt
|
Gold Equivalent
|
28.4 g/t
|
222 koz
|
Commodity Production Costs:
| Commodity | Units | Average |
All-in sustaining costs (AISC)
|
Gold
|
AUD
|
......
|
Assumed price
|
Gold
|
AUD
|
......
|
* According to 2022 study / presentation.
† Net of By-Product.
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2022 Study Costs and Valuation Metrics :
Metrics | Units | LOM Total |
Pre-Production capital costs
|
$M AUD
|
......
|
Processing OpEx
|
$M AUD
|
23
|
Transportation (haulage) costs
|
$M AUD
|
7
|
Total OpEx
|
$M AUD
|
......
|
Royalty payments
|
$M AUD
|
......
|
Gross revenue (LOM)
|
$M AUD
|
......
|
Pre-tax Cash Flow (LOM)
|
$M AUD
|
......
|
Pre-tax NPV @ 5%
|
$M AUD
|
......
|
Pre-tax IRR, %
|
|
......
|
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