Overview
Status | Care and Maintenance |
Mine Type | Underground |
Commodities |
|
Mining Method |
|
Mine Life | 12 years (as of Jan 1, 2016) |
The Kemess Project is at an advanced stage – it has an approved environmental assessment certificate and all permits required to commence construction. There are currently no mining activities at the Kemess site and on-site activities consist of care and maintenance work.
The property is host to the former Kemess South (“KS”) Mine (operated from 1998 to 2011), the Kemess Underground (“KUG”) deposit, and the Kemess East (“KE”) deposit. The KUG project will use existing infrastructure originally used for the KS Mine which remain at site.
The Kemess Project will continue to be on care and maintenance in 2023. |
Source:
p. 63
Centerra’s wholly owned subsidiary (directly held), AuRico is the 100% holder of the rights to the Kemess Project.
Contractors
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Deposit Type
- Porphyry
- Volcanic hosted
- Intrusion related
Summary:
The Kemess Property is host to the Kemess South (KS), Kemess Underground (KUG) and Kemess East (KE) Deposits as well as the Kemess Offset Zone (KOZ) prospect.
The Kemess Underground property is predominantly underlain by a thick (>1,000 m) succession of andesitic flows (Takla Group). The Takla volcanic rocks host a significant portion of the copper-gold mineralization and display phyllic alteration at Kemess North. On the surface is mostly a distinctive feldspar porphyritic unit (bladed feldpsar porphyry – BFP) with some sections of a distinctive augite phyric unit (augite andesite porphyry – AAP). Mantling the northern and eastern limits of the Kemess Underground area is the Hazelton Group-Toodoggone formation. The structurally controlled phyllic sections of this polylithic fragmental dacite in the southeastern area of the deposit can carry anomalous gold concentrations. The evidence suggests that basement structures and conduits that allowed extrusion of the local Toodoggone volcanic assemblage underlie the Kemess Underground area.
The most prominent structure traversing the Kemess Underground area is the Kemess North (KN) Thrust Fault, an east-west trending south dipping reverse fault that truncates the Kemess North pluton and associated mineralization at depth. The KN Fault and the Kemess North pluton seem to be related with the KN Fault creating the pathway for the KUG pluton to intrude. Further movement along the KN Fault subsequently truncated the Kemess North Pluto ........

Summary:
The opportunity to exploit the Kemess Underground (KUG) gold-copper-silver deposit by underground mining methods such as longhole open stoping, sub-level caving, and block cave mining methods, with the block cave approach recommended due to superior economics. As a result, AuRico (then Northgate Minerals) elected to conduct a Feasibility Study (FS) for the Kemess Underground (KUG) deposit based on block caving.
The planned production schedule calls for 107.3 Mt of ore mined at a head grade of 0.27% Cu and 0.54 g/t Au and 1.99 g/t Ag.
Triple declines will be developed from surface comprising access, intake air, and conveyor declines. The access decline will provide access for personnel, equipment, and materials/consumables.
The final design establishes a single extraction level at the 1140 mRL (Figure 5.3) that includes 582 drawpoints (291 drawbells) over a footprint that is approximately 570 m eastwest and 90 m to 300 m north-south. The cave will be initiated in the highest grade ore in the east of the orebody and progress to the southwest over the life of the mine. An 18 m high undercut will be established above the undercut level, with this level at the 1158 mRL and accessed via ramps from the extraction level.
Ore will be recovered on the extraction level using 8.6 m³ (17 t) load-haul-dump (LHD) machines and dumped into one of four 55” x 42” jaw crushers located to the south of the footprint. Transfer conveyors will then transpo ........

Source:

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Flow Sheet:
Summary:

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Projected Production:
Commodity | Product | Units | Avg. Annual | LOM |
Gold
|
Metal in ore
|
koz
| | 1,868 |
Silver
|
Metal in ore
|
oz
| | ......  |
Copper
|
Metal in ore
|
M lbs
| | ......  |
Gold
|
Metal
|
koz
| 106 | |
Copper
|
Metal
|
M lbs
| ......  | |
Operational Metrics:
Metrics | |
Daily processing capacity
| 35,000 t * |
Annual processing capacity
| 12.7 Mt * |
Waste tonnes, LOM
| 2,975,734 t * |
Ore tonnes mined, LOM
| 107,381,498 t * |
Total tonnes mined, LOM
| 110,357,232 t * |
* According to 2016 study.
Reserves at December 31, 2022:
The mineral reserves are estimated based on an NSR cut-off of C$17.30 per tonne and takes into consideration metallurgical recoveries, concentrate grades, transportation costs and smelter treatment charges in determining economic viability.
The mineral resources are estimated based on an NSR cut-off of C$15.00 per tonne and takes into consideration metallurgical recoveries, concentrate grades, transportation costs and smelter treatment charges.
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
107,381 kt
|
Gold
|
0.5 g/t
|
1,868 koz
|
Probable
|
107,381 kt
|
Silver
|
1.99 g/t
|
6,878 koz
|
Probable
|
107,381 kt
|
Copper
|
0.27 %
|
630 M lbs
|
Indicated
|
173,719 kt
|
Gold
|
0.31 g/t
|
1,737 koz
|
Indicated
|
173,719 kt
|
Silver
|
1.55 g/t
|
8,632 koz
|
Indicated
|
173,719 kt
|
Copper
|
0.18 %
|
697 M lbs
|
Inferred
|
47,700 kt
|
Gold
|
0.34 g/t
|
529 koz
|
Inferred
|
47,700 kt
|
Silver
|
1.65 g/t
|
2,530 koz
|
Inferred
|
47,700 kt
|
Copper
|
0.2 %
|
210 M lbs
|
Source:

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Corporate Filings & Presentations:
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