Overview
Stage | Production |
Mine Type | Open Pit / Underground |
Commodities |
|
Mining Method |
- Truck & Shovel / Loader
- Longhole stoping
- Avoca
- Room-and-pillar
|
Processing |
- Flotation
- ROM/dump leach
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in leach (CIL)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 16 years (as of Jan 1, 2020) |
Sukari a large-scale low-cost open pit and underground mine |
Source:
p. 42
Underground Mining Contractor: Barminco
Summary:
Gold mineralization at Sukari is hosted exclusively by porphyry. The lack of significant gold grades in chemically reactive serpentinitic wall rocks can be explained in one of two ways:
• The porphyry represented a favourable host either because of its composition, relative to mineralising fluids, or its mechanical properties or both.
• The Sukari Porphyry was relocated, relative to wall rock sequences, by faulting after gold mineralization.
While significant post-mineralization faulting has possibly occurred, the second scenario is unlikely. Porphyry dykes in the hangingwall of the main porphyry body show gold mineralization of essentially the same character as that in the main porphyry and wall rocks immediately adjacent to those dykes are also barren. Those dykes range in thickness from a few centimetres to several metres. It is not reasonable to postulate that they, along with the main porphyry body, were all relocated by faulting after mineralization.
Certainly it is evident that the Sukari Porphyry has acted as a rigid body surrounded by weaker rocks. Footwall and hangingwall rocks have taken up strain by development of strong schistosity, almost certainly accompanied by large decreases in volume. The porphyry has taken up strain by development of predominantly brittle fault structures.
The porphyry host for the mineralization has a strike length of approximately 2,300 m, and ranges in thickness from 100 m to approximately 600 m (Cavaney 2005). Gold mineralization within this is not continuous and its deposition has been influenced by major long-lived structures, the most important of which are tabular sheets of crackle breccia.
Mining Methods
- Truck & Shovel / Loader
- Longhole stoping
- Avoca
- Room-and-pillar
Summary:
Ore and waste are mined using conventional open pit mining methods. The operation utilises selective mining techniques to separate ore and waste. Provision has been made for drilling and blasting all primary and oxide materials.
The Sukari underground mine is a trackless diesel mine, with all equipment rubber tyred and self- powered. The workings are accessed via a ramp system declining at a gradient of 1 in 7. Levels are typically developed at 15 metre vertical intervals, although this is dependent on orebody geometry and mining method.
Mining method: Long-hole stoping, room and pillar, avoca modified.
Processing
- Flotation
- ROM/dump leach
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in leach (CIL)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The process route encompasses:
• Crushing
• Stockpiling crushed ore
• Grinding
• Flotation of a bulk sulphide concentrate
• Thickening of the concentrate and the flotation tailings
• Fine milling of the concentrate
• Leaching the precious metals from the concentrate and/or flotation tailings in a dilute cyanide solution
• Adsorbing the precious metals onto activated carbon
• Eluting (or desorbing) the precious metals from the carbon
• Recovering the precious metals as gold doré
• Combining the flotation tailings and leached concentrate and pumping to the TSF.
Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | ......  | ......  |
Gold
|
Head Grade, g/t
| 1.28 | 1.26 | 1.57 | 1.65 | 1.4 |
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Reserves at July 18, 2019:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven & Probable
|
In-Situ (UG)
|
4 Mt
|
Gold
|
4.7 g/t
|
0.6 M oz
|
Proven & Probable
|
Stockpiles
|
20.9 Mt
|
Gold
|
0.5 g/t
|
0.3 M oz
|
Proven & Probable
|
In-Situ (OP)
|
163.6 Mt
|
Gold
|
1.1 g/t
|
6 M oz
|
Proven & Probable
|
Total
|
188.4 Mt
|
Gold
|
1.1 g/t
|
7 M oz
|
Measured & Indicated
|
Total
|
321 Mt
|
Gold
|
1.01 g/t
|
10.3 M oz
|
Inferred
|
Total
|
12 Mt
|
Gold
|
1.49 g/t
|
0.59 M oz
|
Corporate Filings & Presentations:
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