Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Overhand Cut & Fill
- Longhole stoping
|
Production Start | ...  |
Mine Life | 5 years (as of Jan 1, 2021) |
The Gosowong operation comprises Kencana mine and Toguraci mine.
No production data is publicly available since Newcrest completed the sale of 100% of Newcrest Singapore Holdings Pte Ltd (NSH) to Indotan Halmahera Bangkit (Indotan) on 5 March 2020. |
Source:
Pt Nusa Halamhera Minerals (NHM) is the joint venture Indonesian company formed to manage the Gosowong Gold Mine.
Newcrest Mining Limited h owned 75 per cent interest in Gosowong’s mining operator, PT Nusa Halmahera Minerals until 5th March 2020. On 5 March 2020, Newcrest completed the sale of 100% of Newcrest Singapore Holdings Pte Ltd (NSH) to Indotan Halmahera Bangkit (Indotan). The remaining 25% owns PT. Aneka Tambang.
Contractors
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Summary:
All economic mineralisation at Gosowong is of low sulphidation epithermal type occurring as mineralised fault systems resulting from high temperature gold and silver bearing hydrothermal fluids. The ore shoots are narrow and approximately planar although irregular and complex in local detail. The deposits are relatively moderate to low in dip averaging around 40-50 degrees in the Kencana – Gosowong structural corridor and sub-vertical in the Toguraci corridor. Silver to gold ratio in the ore is approximately 1:1.
The Toguraci low sulphidation epithermal gold vein deposits are located 2 km south west of the Gosowong mine and form part of the Gosowong Goldfield. The vein structures at Toguraci are narrow with horizontal widths typically ranging between 0.1m and 5m.
The Kencana mineralised system is a complex intersecting network of structures consisting of well-developed epithermal vein zones (K1 and K2) and link structures.
Mining Methods
- Overhand Cut & Fill
- Longhole stoping
Summary:
The open-pit method mining operation in Gosowong has been completed, and currently Gosowong Gold Mine is actively conducting mining activities on its two underground production areas; Kencana, and Toguraci, by combining the mining methods of overhand cut and fill, and stoping.
Kencana Underground Mine commenced its operations in July 2005 and has been productive until today. While Toguraci is another active production area in Gosowong with characteristics unlike other underground mining operations, as the underground area of Toguraci contains geothermal manifestation in the form of hot water source.
The underground mining department of PTNHM operates this mining unit by an extra-effort management. In addition to dewatering procedure, or to pump the resulted hot water out of the mine, it needs to conduct air cooling using an underground air cooler unlike the typical one found in most mines.
These dewatering and air cooling activities are conducted around the clock. The hot water is pumped out of the mining site and stored at a settlement pond for cooling process before channeled into nature.
Source:

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Source:
Summary:

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Production:
2020 production from Gosowong is shown up to the divestment date of 4 March 2020.
Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
oz
| ......  | ......  | 251,390 | 295,876 | 197,463 | 331,555 |
Silver
|
oz
| ......  | ......  | ......  | ......  | ......  | ......  |
All production numbers are expressed as metal in doré.
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Operational Metrics:
Metrics | 2019 | 2018 | 2017 | 2016 | 2015 |
Ore tonnes mined
| 690 kt | 679 kt | 564 kt | 416 kt | 716 kt |
Total tonnes mined
| 808 kt | 767 kt | 664 kt | 484 kt | 878 kt |
Tonnes milled
| 708 kt | 704 kt | 565 kt | 479 kt | 738 kt |
Plant annual capacity
| | 800 kt | 800 kt | 800 kt | |
Reserves at December 31, 2019:
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
1.2 Mt
|
Gold
|
7.5 g/t
|
0.3 M oz
|
Probable
|
1.2 Mt
|
Silver
|
11 g/t
|
0.43 M oz
|
Indicated
|
2.7 Mt
|
Gold
|
10 g/t
|
|
Indicated
|
2.7 Mt
|
Silver
|
14 g/t
|
|
Inferred
|
0.41 Mt
|
Gold
|
8.2 g/t
|
|
Inferred
|
0.41 Mt
|
Silver
|
11 g/t
|
|
Total Resource
|
3.1 Mt
|
Gold
|
10 g/t
|
1 M oz
|
Total Resource
|
3.1 Mt
|
Silver
|
14 g/t
|
1.3 M oz
|
Commodity Production Costs:
| Commodity | Units | 2019 | 2018 | 2017 | 2016 |
All-in sustaining costs (sold)
|
Gold
|
USD
|
......
|
882 / oz†
|
757 / oz†
|
935 / oz†
|
† Net of By-Product.
Financials:
| Units | 2020 | 2019 | 2018 | 2017 | 2016 |
Capital expenditures (planned)
|
M USD
| ......  | |
|
|
|
Sustaining costs
|
M USD
| | ......  |
25
|
33
|
48
|
Revenue
|
M USD
| | ......  |
351
|
350
|
257
|
EBIT
|
M USD
| | ......  |
58
|
79
|
48
|
EBITDA
|
M USD
| | ......  |
148
|
177
|
87
|
Operating Cash Flow
|
M USD
| | ......  |
146
|
186
|
102
|
Corporate Filings & Presentations:
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