Overview
| Stage | Production |
| Mine Type | Underground |
| Commodities |
|
| Mining Method |
|
| Production Start | ...  |
| Mine Life | 18 years (as of Jan 1, 2018) |
Source:
p. 181,219
| Company | Interest | Ownership |
|
Government of Tanzania
|
16 %
|
Indirect
|
|
Barrick Gold Corp.
|
84 %
|
Indirect
|
|
Twiga Minerals Corporation Ltd.
(operator)
|
100 %
|
Direct
|
On September 17, 2019, Barrick acquired all of the Acacia Mining plc. Acacia became a wholly-owned subsidiary of Barrick called Barrick TZ Limited.
On January 24, 2020, Barrick announced that the Company had ratified the creation of Twiga Minerals Corporation, formalizing the establishment of a joint venture between Barrick and the GoT and resolution of all outstanding disputes between Barrick and the GoT. The Government of Tanzania will receive a free carried shareholding of 16% in each of the former Acacia mines (Bulyanhulu, Buzwagi and North Mara). The GoT’s 16% free-carried interest was made effective on January 1, 2020.
Twiga will provide management services to the mines.
Contractors
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Summary:
The main rock types in the mine area are bimodal mafic and felsic volcanics rocks of the West Kahama segment of the Nyanzian age Kahama Greenstone Belt. The mafic rocks are predominantly flows, overlain by a series of felsic pyroclastics and ash tuffs. Argillites occur within the mafic flows and at the mafic/felsic contact and are the principal host for the mineralization. Mafic dykes/sills, commonly lensoid along their northwest strike, are a significant part of the lithological package southwest of the deposit itself. The Bukoli Granite, which separates the Kahama belt from the Rwamagaza belt to the west, lies approximately 3 km southwest of the mine. Together with regional faults, the Bukoli Granite forms the bounds of a rhomboid-shaped greenstone domain at Bulyanhulu.
The gold mineralization, together with copper sulphides and silver, occurs in quartz veins localized along steeply-dipping structures parallel to the regional northwest strike. Nine of these extensive quartz vein systems have been discovered so far with Reef 1, hosted by a shear zone developed preferentially along the most extensive sedimentary unit, the most significant. The ore is characterized by sub continuous lenses and veins of black quartz concentrated in narrow shear zones. An initial stage of syn-depositional barren clastic pyrite has been identified, overprinted by a polymetallic hydrothermal event associated with gold and copper mineralization. Alteration, dominantly carbonatization ........
Summary:
In the second half of 2017 Acacia took the decision to place Bulyanhulu on reduced operations due to the inability to export gold concentrate. Following the transition to reduced operations in Q4 2017 Bulyanhulu is running on tailings.
Underground production successfully restarted at Bulyanhulu in Q4 2020, with the plant recommencing processing of underground ore.
Bulyanhulu mine utilizes a long hole stoping method.
Mineralization is associated with steeply-dipping reefs containing gold, silver and copper in sulphides.
Source:
Flow Sheet:
Summary:
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Reserves at December 31, 2021:
| Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
|
Probable
|
In-Situ (UG)
|
12 Mt
|
Gold
|
7.76 g/t
|
3 M oz
|
|
Probable
|
In-Situ (UG)
|
12 Mt
|
Copper
|
0.37 %
|
98 M lbs
|
|
Probable
|
In-Situ (UG)
|
12 Mt
|
Silver
|
6.92 g/t
|
2.7 M oz
|
|
Proven & Probable
|
In-Situ (UG)
|
12 Mt
|
Gold
|
7.76 g/t
|
3 M oz
|
|
Proven & Probable
|
In-Situ (UG)
|
12 Mt
|
Copper
|
0.37 %
|
98 M lbs
|
|
Proven & Probable
|
In-Situ (UG)
|
12 Mt
|
Silver
|
6.92 g/t
|
2.7 M oz
|
|
Indicated
|
In-Situ (UG)
|
20 Mt
|
Gold
|
8.92 g/t
|
5.7 M oz
|
|
Indicated
|
In-Situ (UG)
|
20 Mt
|
Copper
|
0.41 %
|
179 M lbs
|
|
Indicated
|
In-Situ (UG)
|
20 Mt
|
Silver
|
7.31 g/t
|
4.6 M oz
|
|
Inferred
|
In-Situ (UG)
|
29 Mt
|
Gold
|
8 g/t
|
7.4 M oz
|
|
Inferred
|
In-Situ (UG)
|
29 Mt
|
Copper
|
0.4 %
|
238 M lbs
|
|
Inferred
|
In-Situ (UG)
|
29 Mt
|
Silver
|
6.3 g/t
|
5.8 M oz
|
Heavy Mobile Equipment as of November 10, 2021:
| HME Type | Quantity |
|
Drill
|
.......................
|
|
Loader
|
.......................
|
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Corporate Filings & Presentations:
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