Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Smelting
- Agitated tank (VAT) leaching
- Counter current decantation (CCD)
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 19 years (as of Jan 1, 2013) |
Source:
p. 42
The Project is held through Newmont Ghana Gold Ltd., an indirectly-wholly owned subsidiary.
Deposit Type
- Orogenic
- Vein / narrow vein
Source:
Summary:
The Akyem mine is an orogenic gold deposit that has oxide and primary mineralization. The gold is found in shear zones within greenschist-facies metasediments that have kilometer-scale vertical and lateral extent. Gold occurs primarily in pyrite and secondarily as native gold in quartz veins.
Source:
Summary:
The mining method at the Akyem mine involves removal of ore and waste rock from an open pit mine. The open pit is an elongated structure consisting of a large western lobe (Main Pit) and a small eastern lobe (East Pit), connected near the surface. The planned pit covers an area of approximately 345 acres (139 hectares).
Mining is conducted using large scale conventional hard rock drill and blast open pit methodology. Run of Mine (ROM) ore is trucked from the pits using CAT 785 DT’s.
Source:
Crusher / Mill Type | Model | Size | Power | Quantity |
SAG mill
|
|
|
|
1
|
Ball mill
|
|
|
|
1
|
Processing
- Smelting
- Agitated tank (VAT) leaching
- Counter current decantation (CCD)
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Source:
Summary:
The ore sources that are being treated in the Akyem mill includes an Oxide ore (consisting of Oxide Mafic and Oxide Greywacke ores), followed by a deeper Primary ore body (consisting of primary Mafic and primary Greywacke ores).
The Akyem gold processing plant was commissioned in 2013 to treat an average of 8.5 million tonnes of ore annually. With the depletion of oxide ore.
The process plant consists of a large conventional SAG and Ball Mill in closed circuit configuration with an annual production rate of >8mt. The rest of the Process Plant consists of a carbon-in-leach circuit with cyanidation followed by elution and refining for gold doré recovery.
Tailings remaining after completion of the processing and precious metals recovery are conveyed by pipeline to a counter-current decantation (CCD) plant where the tailings are rinsed with decant return water to reduce WAD cyanide concentrations to less than 50ppm WAD cyanide prior to final disposal. After the CCD circuit, the tailings are transferred via a lined tailings trench, to an engineered, lined tailings storage facility (TSF) for permanent disposal.
Sparging is a closed circuit mixing process that passes pH-adjusted water from a mixing tank through the isotainer in a continuous circuit until the required concentration of liquid cyanide is achieved. On completion of the sparging process, the liquid cyanide is transferred from the mixing tank to a dedicated storage tank, ready for delivery by pipeline to the process plant. All pipelines used for the transfer of cyanide to the process plant or within the process plant are either double-piped or installed above containment facilities to prevent the escape of leaks or spills to the surrounding surface.
The cyanide mixing facility at Akyem is specifically designed to handle the bulk sparging operations.
Recoveries & Grades:
Commodity | Parameter | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Recovery Rate, %
| 90.6 | 90.8 | 91.2 | 92.3 | 91.7 | 90.8 |
Gold
|
Head Grade, oz/ton
| 0.05 | 0.05 | 0.05 | 0.06 | 0.06 | 0.06 |
Production:
Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 | 2014 |
Gold
|
koz
| 371 | 422 | 414 | 473 | 470 | 473 | 472 |
All production numbers are expressed as metal in doré.
Operational Metrics:
Metrics | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Total tonnes mined
| 31,041 k tons | 35,687 k tons | 35,675 k tons | 35,227 k tons | 36,538 k tons | 35,832 k tons |
Ore tonnes mined
| 7,793 k tons | 12,845 k tons | 11,709 k tons | 9,058 k tons | 9,899 k tons | 10,325 k tons |
Waste
| 23,248 k tons | 22,842 k tons | 23,966 k tons | 26,169 k tons | 26,639 k tons | 25,507 k tons |
Tonnes processed
| 9,007 k tons | 8,660 k tons | 8,566 k tons | 9,273 k tons | 9,276 k tons | 7,991 k tons |
Daily mining rate
| | | 88 kt | 91 kt | 91 kt | 90 kt |
Annual processing capacity
| | | 7.7 Mt | 8.5 Mt | 8.5 Mt | 8.5 Mt |
Reserves at December 31, 2020:
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven & Probable
|
Stockpiles
|
15,100 kt
|
Gold
|
0.82 g/t
|
400 koz
|
Proven & Probable
|
In-Situ (OP)
|
34,200 kt
|
Gold
|
1.7 g/t
|
1,870 koz
|
Proven & Probable
|
Total
|
49,300 kt
|
Gold
|
1.43 g/t
|
2,270 koz
|
Measured & Indicated
|
In-Situ (OP)
|
2,300 kt
|
Gold
|
0.54 g/t
|
50 koz
|
Measured & Indicated
|
In-Situ (UG)
|
5,300 kt
|
Gold
|
3.85 g/t
|
650 koz
|
Measured & Indicated
|
Total
|
7,600 kt
|
Gold
|
2.86 g/t
|
700 koz
|
Inferred
|
In-Situ (OP)
|
2,600 kt
|
Gold
|
1.2 g/t
|
100 koz
|
Inferred
|
In-Situ (UG)
|
3,700 kt
|
Gold
|
3.31 g/t
|
390 koz
|
Inferred
|
Total
|
6,300 kt
|
Gold
|
2.42 g/t
|
490 koz
|
Commodity Production Costs:
| Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Total cash costs (sold)
|
Gold
|
USD
|
621 / oz†
|
558 / oz†
|
546 / oz†
|
573 / oz†
|
497 / oz†
|
435 / oz†
|
All-in sustaining costs (sold)
|
Gold
|
USD
|
757 / oz†
|
718 / oz†
|
705 / oz†
|
664 / oz†
|
584 / oz†
|
572 / oz†
|
† Net of By-Product.
Financials:
| Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Sustaining costs
|
M USD
| 26 | 28 | 40 |
26
|
24
|
44
|
Capital expenditures
|
M USD
| 27 | 33 | 40 |
26
|
22
|
45
|
Revenue
|
M USD
| 671 | 585 | |
|
|
|
Pre-tax Income
|
M USD
| 291 | 176 | 125 |
152
|
214
|
227
|
Heavy Mobile Equipment as of December 31, 2018:
Source:
p.48
HME Type | Size | Quantity |
Excavator
|
|
2
|
Shovel
|
|
2
|
Truck (haul)
|
136 t
|
19
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
General Manager
|
Joshua Mortoti
|
|
Feb 26, 2021
|
Health & Safety Manager
|
Yaw Kyei Amoako
|
|
Feb 26, 2021
|
Mine Maintenance Superintendent
|
Raul Chauca
|
|
Feb 26, 2021
|
Staff:
Total Workforce | Year |
1,400
|
2018
|
1,400
|
2017
|
1,400
|
2016
|
1,450
|
2015
|
Corporate Filings & Presentations: