Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Sub-level caving
- Longhole open stoping
|
Production Start | ...  |
The Company achieved the first production from Golden Point Underground (GPUG) in the fourth quarter of 2021 as previously guided to the market. GPUG will continue to ramp-up with future development and will initially supplement, then eventually fully replace the existing Frasers Underground gold production. |
Source:
p. 10,27
Oceana Gold Limited holds 100% interests in the Frasers mine and is a wholly owned subsidiary of OceanaGold Corp.
Contractors
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Deposit Type
- Orogenic
- Vein / narrow vein
- Breccia pipe / Stockwork
Summary:
At the Frasers open pit and Frasers underground mine (FRUG), deposits are centred on mining the hangingwall shear. In outcrop, the shear typically dips at 15 to 20 degrees to the east and is approximately 5 metres thick. At depth, the dip of the shear flattens to approximately 5 to 10 degrees and develops into an approximately 20 to 30 metres thick mineralised high-grade zone of quartz cataclasite, and mineralised schist. Within the open pit, gold mineralisation comprises mineralised schist and cataclasite, shear-parallel quartz veins and arrays of sub-vertical quartz veins. hangingwall shear and arrays of subvertical quartz veins account for most of the mineralisation within the open pit, although there are a few shear-parallel quartz veins. These veins typically splay off the base of the hangingwall Shear and dip at between 5 and 10 degrees to the west.
A large amount of erratic mineralisation occurs between the base of the hangingwall shear and the footwall fault. At the resource drilling stage, this mineralisation manifests as poorly developed clusters of elevated gold grades, which often appear discontinuous. During mining however, these typically present as extensive zones of quartz vein arrays and mineralised shears. The footwall fault lies between 80 metres and 120 metres below the hangingwall shear and is identified as a cataclastic zone up to 10 metres thick. To date, no economic mineralisation has been located below the footwall fault.
FRUG encompasses the down-d ........

Mining Methods
- Sub-level caving
- Longhole open stoping
Summary:
The Frasers underground orebody encompasses the down dip continuation of the Hangingwall shear mined in the Frasers open pit. The orebody is relatively shallow dipping (15 – 20 degrees) to the east. The orebody is tabular with undulations and has a thickness varying between 5 to 30 metres.
The mining method used underground involves 15-metre-wide open stopes with 6 metre yielding pillars between stopes. Mining areas are separated by 20 metres to 60 metres wide regional pillars. The mining areas are generally restricted to about 120 metres width and 160 metres length. Mine production targets the high-grade ore at the top of the 30 metres thick mineralisation. Stope heights vary between drive height (5 metres) and up to 25 metres.
The most utilised mining method at FRUG is retreat long hole open stoping. In addition, sub-level caving is used to recover some of the regional pillars after they are no longer required. Declines and access drives are mined to a 5.0mW x 5.5mH arched profile. Ore drives are mined to a 5.0mWx5.0mH profile. This allows enough space for services, secondary fans, vent ducts and mobile equipment. Stoping panels were designed based on the main considerations below:
- Ore drives placed at 21m centres to allow for 15m wide stopes with 6m yielding pillars between them. There are no secondary stopes designed to be extracted following the mining of the primaries;
- Ore drives positioned such that they will have a gentle uphi ........

Flow Sheet:
The plant's crushing and grinding comprises the following components and stages:
- Two single stage jaw crushing circuits, which reduce the ore to a top size of approximately 200mm; the products from these two circuits are directly fed to the two SAG mills and an emergency feeder on the conveyor system feeding the higher capacity circuit provides continuity of feed to the grinding circuit if the jaw crusher feed is interrupted;
- A complex grinding circuit to reduce the particle size of the ore to 80% passing at 130 µm; the original, higher capacity crushing circuit feeds a 2,300kW SAG mill and the new crushing circuit feeds a 1,500kW SAG mill; discharge from the two SAG mills is combined with the discharge from one of the two ball mills (2,300kW) and directed to the primary cyclone cluster. Discharge from the higher capacity ball mill (2,500kW) is fed to the secondary cyclone cluster. The underflows from both cyclone clusters are combined and fed in parallel to the flash flotation circuit and two ball mills (2,300kW and 2,500kW);
- Regrind of the flotation concentrate is performed in a 900kW ball mill to 80% passing of 15 µm to improve pressure oxidation kinetics.
Flow Sheet:
Summary:

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Combined production numbers are reported under
Macraes Operation
Operational Metrics:
Metrics | 2021 | 2020 | 2019 |
Ore tonnes mined
| ......  | ......  | 994 kt |
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Reserves at December 31, 2021:
The Mineral Reserves reported a 1.61 g/t Au.
The Mineral Resource reported using a 1.25 g/t Au.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
0.33 Mt
|
Gold
|
2.23 g/t
|
|
Probable
|
3.21 Mt
|
Gold
|
1.88 g/t
|
|
Proven & Probable
|
3.54 Mt
|
Gold
|
1.91 g/t
|
0.22 M oz
|
Measured
|
0.7 Mt
|
Gold
|
2.98 g/t
|
|
Indicated
|
6.1 Mt
|
Gold
|
2.48 g/t
|
|
Measured & Indicated
|
6.9 Mt
|
Gold
|
2.53 g/t
|
0.56 M oz
|
Inferred
|
0.3 Mt
|
Gold
|
2.1 g/t
|
|
Operating Costs:
| Units | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
UG mining costs ($/t mined)
|
USD
| 56.3 | 43.8 | 37.9 | 41.1 | 38.5 | 37.8 |
Corporate Filings & Presentations:
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