Deposit Type
- Vein / narrow vein
- Orogenic
Summary:
The Ahafo mine is composed of three orogenic gold deposits that have oxide and primary mineralization. The gold is hosted in brittle shear zones cutting granitic intrusives that have kilometer-scale vertical and lateral extent. Gold occurs primarily in pyrite and secondarily as native gold in quartz veins.
Summary:
The mining method at the Ahafo mine involves removal of ore and waste rock from an open pit mine. Ahafo has three open pits (Subika, Amoma and Awonsu), with current mining from the Amoma and Subika pits. Subika is in the third stage of a four stage pit, whereas Amoma is in the final stage of a two-stage pit. Ahafo’s available mining fleet consists of open pit loaders and 38 dump trucks, each with a 144 tonne payload.
Processing Technologies
- Counter current decantation (CCD)
- Agitated tank leaching
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Summary:
The processing plant was commissioned in 2006 to process 7.5 million tonnes of primary and oxide ore per year. With the depletion of oxide ore, the current plant throughput has decreased to 6.5 million tonnes per year. The processing plant consists of a crushing plant, a grinding circuit, carbon in leach tanks, elution circuit, counter current decantation circuit and a tailings disposal facility.
Production:
| Commodity | Units | 2017 | 2016 | 2015 | 2014 | 2013 |
|
Gold
|
koz
| ......  | ...... | 332 | 442 | 570 |
All production numbers are expressed as metal in doré.
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Operational Metrics:
| Metrics | 2017 | 2016 | 2015 |
|
Plant annual capacity
| ...... | 6.5 Mt | 6.5 Mt |
|
Daily processing rate
| ...... | 95 kt | |
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Reserves at December 31, 2017:
| Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
Stockpiles
|
37,600 kt
|
Gold
|
0.95 g/t
|
1,160 koz
|
|
Proven
|
In-Situ (OP)
|
15,600 kt
|
Gold
|
2.13 g/t
|
1,060 koz
|
|
Proven
|
Total
|
53,200 kt
|
Gold
|
1.3 g/t
|
2,220 koz
|
|
Probable
|
In-Situ (OP)
|
49,300 kt
|
Gold
|
1.71 g/t
|
2,700 koz
|
|
Probable
|
In-Situ (UG)
|
10,500 kt
|
Gold
|
4.68 g/t
|
1,590 koz
|
|
Probable
|
Total
|
59,800 kt
|
Gold
|
2.23 g/t
|
4,290 koz
|
|
Proven & Probable
|
Stockpiles
|
37,600 kt
|
Gold
|
0.95 g/t
|
1,160 koz
|
|
Proven & Probable
|
In-Situ (OP)
|
64,900 kt
|
Gold
|
1.81 g/t
|
3,760 koz
|
|
Proven & Probable
|
In-Situ (UG)
|
10,500 kt
|
Gold
|
4.67 g/t
|
1,590 koz
|
|
Proven & Probable
|
Total
|
113,000 kt
|
Gold
|
1.79 g/t
|
6,510 koz
|
|
Measured
|
In-Situ (OP)
|
800 kt
|
Gold
|
0.53 g/t
|
10 koz
|
|
Measured
|
Total
|
800 kt
|
Gold
|
0.53 g/t
|
10 koz
|
|
Indicated
|
In-Situ (OP)
|
31,200 kt
|
Gold
|
1.16 g/t
|
1,160 koz
|
|
Indicated
|
In-Situ (UG)
|
10,300 kt
|
Gold
|
4.51 g/t
|
1,500 koz
|
|
Indicated
|
Total
|
41,500 kt
|
Gold
|
1.99 g/t
|
2,660 koz
|
|
Measured & Indicated
|
In-Situ (OP)
|
32,000 kt
|
Gold
|
1.14 g/t
|
1,170 koz
|
|
Measured & Indicated
|
In-Situ (UG)
|
10,300 kt
|
Gold
|
4.51 g/t
|
1,500 koz
|
|
Measured & Indicated
|
Total
|
42,300 kt
|
Gold
|
1.96 g/t
|
2,670 koz
|
Heavy Mobile Equipment as of December 31, 2017:
| HME Type | Size | Quantity |
|
Shovel
|
|
3
|
|
Truck (haul)
|
141 t
|
38
|