Overview
Stage | Construction |
Mine Type | Open Pit / Underground |
Commodities |
|
Mining Method |
- Truck & Shovel / Loader
- Longhole open stoping
|
Processing |
- Gravity separation
- Smelting
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 16 years (as of Jan 1, 2022) |
Latest News | Red 5 chooses Macmahon at King of the Hills March 9, 2021 |
Source:
p. 8
Company | Interest | Ownership |
Red 5 Ltd.
|
100 %
|
Indirect
|
Deposit Type
- Vein / narrow vein
- Orogenic
Summary:
The KOTH mineralisation is considered to be part of an Archean Orogenic gold deposit with many similar characteristics to other gold deposits within the Eastern Goldfields of the Yilgarn Craton.
Gold mineralisation is associated with sheeted and stockwork quartz vein sets within a hosting granodiorite stock and pervasively carbonate altered ultramafic rocks. Mineralisation is thought to have occurred within a brittle/ductile shear zone with the main thrust shear zone forming the primary conduit for the mineralising fluids. Preexisting quartz veining and brittle fracturing of the granite created a network of second order conduits for mineralising fluids.
Brittle fracturing along the granodiorite contact generated radial tension veins, perpendicular to the orientation of the granodiorite, and zones of quartz stockwork. These stockwork zones are seen in both the granodiorite and ultramafic units and contain mineralisation outside the modelled continuous vein system (High Grade Veins).
Gold appears as free particles (coarse gold) or associated with traces of base metals sulphides (galena, chalcopyrite, pyrite) intergrown within quartz along late stage fractures.
The Western Flank mineralised zone strikes 30 degrees west of true north over a distance of 700m and plunges to the southwest. Individual lodes dip east at 35 to 45 degrees. Eastern Flank mineralisation strikes 30 degrees east of true north over a distance of 700m and is vertical. Stockwork mineralisation runs along the contact of the granodiorite/ultramafic contact which strikes 30 degrees east of true north over a distance of 4km and is vertical. Mineralisation has been tested to approximately 400m below surface and remains open.
Mining Methods
- Truck & Shovel / Loader
- Longhole open stoping
Summary:
The FFS open pit mining operations will deliver ore to a new processing plant to be constructed at KOTH.
The mining method proposed for all deposits is the conventional use of excavators in backhoe configuration as the primary loading fleet, loading rigid off-highway rear dump trucks. This configuration is common to the Goldfields region of Western Australia (WA) and is considered a low-risk solution.
There is 1.5Mdmt of TMM in the March Quarter 2022, comprising 870 k dmt of waste and 630 k dmt of ore. The waste material is being classed as capitalised pre-strip to access a sustainable source of ore feed at KOTH for subsequent periods. The ore is placed on the ROM pad.
Mining at Rainbow starts in June Quarter 2022 and is completed 15 months later. While waste movement is required to access ore, sustainable ore production occurs within the first quarter of mining, and therefore the waste has not been defined as capitalised pre-strip. It should be noted, however, that the ore will likely only become available in the latter half of that quarter.
There is a contingency for ensuring continuity of ore feed in the initial year of process plant operation with approximately 1.7Mdmt of ore on existing surface stockpiles.
Mining at Cerebus-Eclipse starts in 2029 and continues for 12 months, with Centauri being a continuation of operation for the mining fleet, starting in 2030. The haul road and infrastructure used at Cerebus-Eclipse will be used for the Centauri operation.
The general progression of the production schedule for KOTH is from south to north, depleting the southern half of the pit in time for the short haul of waste from the northern cut-backs. Depleting the southern half of the KOTH pit also results in the open cut mining operation avoiding the UG portal and vent raise for the UG operation mine plan. This approach removes the requirement for any capital works required in establishing a new portal, providing access to that portal location (both surface and underground) and establishing supporting underground infrastructure such as a new vent raise.
While the average grade of the southern half of the pit is not as high as in the northern half of the pit, the lower strip ratio in the south compensates for this lower grade and provides earlier access to sustainable ore supply.
Waste from the open pits will be dumped on a ‘short haul first’ logic. From an immediate cost perspective, this is advantageous; however, this approach will need to be balanced with the levelling of truck numbers over the LOM, so as not to incur additional mobilisation/demobilisation costs for short periods of operation.
The waste dump capacities as designed can contain all waste from the pits. The KOTH external waste dumps do exceed the recommended height limits later in the LOM, which will need to be proactively addressed during the operational period.
The primary mining fleet for the KOTH open pit are 250 t class excavators (in backhoe configuration), paired with 140 t class haul trucks.
The primary mining fleet for the satellite deposits is one 120 t class excavator (in backhoe configuration), paired with five 100 t class haul trucks.
KOTH is currently an operating underground gold mine, and the KOTH FFS is predicated on the continuation of existing underground mining practices. Mine design parameters are based on current site guidelines, which are well understood and have been successfully implemented.
The proposed primary mining method is long-hole open stoping, with minor amounts of airleg stoping in flat dipping areas of the orebody (<1% of ore tonnes). Stoping will follow a top-down sequence, commencing at the extremities of each level and retreating to the level access. Rib pillars will remain between adjacent stopes to maintain mine stability. The proposed mining methods and sequence are generally a continuation of current operating practices at an increased production rate.
Crusher / Mill Type | Model | Size | Power | Quantity |
SAG mill
|
|
|
|
|
Processing
- Gravity separation
- Smelting
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The KOTH processing facility has essentially been designed to process 4Mtpa of fresh open pit and underground ore. However, allowance has been incorporated into the design for future throughput upgrade to 6Mtpa with limited production interruption and low capital requirements. The primary crushing circuit has been designed for 6Mtpa. The mill selection and the layout of the grinding circuit allow for a future ball mill, with allowance provided for a second gravity recovery line. The design also allows for two additional future leach tanks and a tailings thickener (if required).
The processing plant will be designed to operate seven days per week at a nominal treatment rate of 500 dry t/h on fresh ore at a grinding circuit utilisation rate averaging 91.3% over the Life of Mine.
The processing facility unit processes are based on proven technology for gold recovery following a processing route of:
• Primary crushing by a gyratory crusher to product size ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| ......  |
Gold
|
Head Grade, g/t
| 1.24 |
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Projected Production:
Commodity | Units | Avg. Annual | LOM |
Gold
|
koz
| 146 | 2,350 |
All production numbers are expressed as metal in doré.
Operational Metrics:
Metrics | |
Stripping / waste ratio
| ......  |
Daily ore mining rate
| ......  |
Waste tonnes, LOM
| ......  |
Ore tonnes mined, LOM
| ......  |
Tonnes processed, LOM
| ......  |
Annual processing capacity
| ......  |
* According to 2020 study.
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Reserves at September 15, 2020:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
In-Situ (OP)
|
62.2 Mt
|
Gold
|
1.1 g/t
|
2,204 koz
|
Probable
|
In-Situ (UG)
|
2.4 Mt
|
Gold
|
2.3 g/t
|
180 koz
|
Probable
|
Total
|
64.6 Mt
|
Gold
|
1.2 g/t
|
2,384 koz
|
Indicated
|
In-Situ (OP)
|
65.8 Mt
|
Gold
|
1.3 g/t
|
2,720 koz
|
Indicated
|
In-Situ (UG)
|
4 Mt
|
Gold
|
2.2 g/t
|
290 koz
|
Indicated
|
Total
|
69.8 Mt
|
Gold
|
1.3 g/t
|
3,010 koz
|
Inferred
|
In-Situ (OP)
|
14.6 Mt
|
Gold
|
1.4 g/t
|
650 koz
|
Inferred
|
In-Situ (UG)
|
6.3 Mt
|
Gold
|
2 g/t
|
410 koz
|
Inferred
|
Total
|
20.9 Mt
|
Gold
|
1.6 g/t
|
1,060 koz
|
Total Resource
|
In-Situ (OP)
|
80.4 Mt
|
Gold
|
1.3 g/t
|
3,370 koz
|
Total Resource
|
In-Situ (UG)
|
10.3 Mt
|
Gold
|
2.1 g/t
|
700 koz
|
Total Resource
|
Total
|
90.7 Mt
|
Gold
|
1.4 g/t
|
4,070 koz
|
Corporate Filings & Presentations:
Document | Year |
Corporate Presentation
|
2021
|
...................................
|
2020
|
...................................
|
2020
|
...................................
|
2019
|
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News:
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