Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Inline Leach Reactor (ILR)
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 14 years (as of Jan 1, 2019) |
Source:
p. 95, 218
Gold Fields Ghana Ltd (“GFG”) owns 100% interest in the Tarkwa operation in Ghana. Gold Fields Limited owns 90% interest in Gold Fields Ghana Limited and the remain 10% is held by the government of Ghana, as required under the mining law of Ghana.
Summary:
The ore bodies are located within the Tarkwaian System, which is an important stratigraphic component of the Ashanti Belt in south-western Ghana. The Ashanti Belt is a north-easterly striking, broadly synclinal structure made up of lower proterozoic sediments and volcanics underlain by the metavolcanics and metasediments of the Birimian System. The Tarkwaian unconformably overlies the Birimian, and is characterised by lowerintensity metamorphism and the predominance of coarse grained, immature sedimentary units
Mineralisation hosted by conglomerates
- Laterally continuous with mid- to longrange predictability
- Clear patterns of mineralisation governed by sedimentary characteristics
- Exploration programmes ongoing to test homogeneity of geology and grade domains
- Targets are both palaeoplacer and hydrothermal.
Summary:
The mine utilises selective surface mining methods to optimise the extraction of the mineralised conglomerate units. Short-term mine planning and forecasts are based on grade controlled models. During mining, fresh rock and transitional zones are drilled and blasted in six-metre lifts, with excavation in three metre flitches.
The mine is owner-operated and has its own load and haul fleet of 13 excavators, which range from 120 to 400 tonnes. The haul fleet includes 67 dump trucks with a payload of 146 tonnes, eight dump trucks with a payload of 240 tonnes and nine dump trucks with a payload of 90 tonnes. The load and haul fleet are supported by an ancillary fleet consisting of dozers, graders, water carts and compactors. A total of 22 owneroperated drill rigs are used for blast hole drilling. Maintenance of the fleet is carried out by Tarkwa mine, while maintenance of the excavators is carried out by contractors.
Mining operations are carried out using contractor mining. Mining occurs from several pits which haul to the processing facility. Blast restrictions are applied to the Pepe 8, Atuabo and Mantraim pits, which will be complete in 2020. Pit wall steepening has been supported by effective wall monitoring and blasting practices. [2019 Mineral Resources and Mineral Reserves Supplement to the Integrated Annual Report. P.96]
Processing
- Gravity separation
- Inline Leach Reactor (ILR)
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Source:
Summary:
Ore is processed utilising a conventional CIL plant, with a gyratory crusher feeding a SAG mill and ball mill. Gold is recovered from solution by electro-winning and smelted in an induction furnace. Current plant capacity is 13.5Mtpa.
LoM tailings deposition requirements are catered for in the short term by wall raise sequences at the operating TSF 1, 2 and 5 facilities. The TSF 5 starting facility, whose downstream construction commenced in 2016, was completed in 2018. In the longer term, LoM tailings deposition requirements will be catered for by planned extended expansions to TSF 1, 2 and 5 and establishment of a new TSF 5 Annex that is planned to be constructed adjacent to TSF 5. [2019 Mineral Resources and Mineral Reserves Supplement to the Integrated Annual Report. P.96]
The initial development, Tarkwa Phase 1, was completed in April 1998 processing 4.7 million tonnes per annum (Mtpa) heap leach feed ore. An expansion, Phase 2, was completed in July 1999 inc ........

Recoveries & Grades:
Commodity | Parameter | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | ......  | ......  | ......  |
Gold
|
Head Grade, g/t
| 1.2 | 1.22 | 1.37 | 1.36 | 1.38 | 1.26 |
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Production:
Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
koz
| ...... ^ | ......  | ......  | 566 | 568 | 586 |
All production numbers are expressed as metal in doré.
^ Guidance / Forecast.
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Operational Metrics:
Metrics | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
Total tonnes mined
| ......  | ......  | ......  | 101,154 kt | 101,421 kt | 87,343 kt |
Ore tonnes mined
| ......  | ......  | ......  | 14,551 kt | 14,754 kt | 13,625 kt |
Waste
| ......  | ......  | ......  | 86,603 kt | 86,667 kt | 73,719 kt |
Stripping / waste ratio
| ......  | ......  | ......  | 6.4 | 5.9 | 5.4 |
Plant annual capacity
| ......  | ......  | ......  | 13.5 Mt | 13.5 Mt | 13.5 Mt |
Tonnes processed
| ......  | ......  | ......  | 13,608 kt | 13,520 kt | 13,553 kt |
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Reserves at December 31, 2019:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Total
|
53,215 kt
|
Gold
|
1.13 g/t
|
1,928 koz
|
Probable
|
Total
|
143,468 kt
|
Gold
|
0.86 g/t
|
3,967 koz
|
Proven & Probable
|
Total
|
196,683 kt
|
Gold
|
0.93 g/t
|
5,894 koz
|
Measured
|
Total
|
70,003 kt
|
Gold
|
1.32 g/t
|
2,960 koz
|
Indicated
|
Total
|
217,569 kt
|
Gold
|
1.02 g/t
|
7,161 koz
|
Inferred
|
Total
|
20,331 kt
|
Gold
|
1.21 g/t
|
791 koz
|
Total Resource
|
Total
|
307,903 kt
|
Gold
|
1.1 g/t
|
10,913 koz
|
Heavy Mobile Equipment as of December 31, 2015:
HME Type | Size | Quantity |
Drill
|
|
22
|
Excavator
|
|
16
|
Truck (dump)
|
240 t
|
8
|
Truck (dump)
|
90 t
|
9
|
Truck (dump)
|
146 t
|
67
|
Corporate Filings & Presentations:
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Aerial view:
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