Overview
Stage | Production |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Sub-level stoping
- Longhole open stoping
- Paste backfill
|
Processing |
- Gravity separation
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Centrifugal concentrator
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
On-Site Camp |
650 person |
Mine Life | 2027 |
Agnew operates two underground mines, namely Waroonga and New Holland, now amalgamated into the Agnew One Mine Complex. |
Latest News | Gold Fields Publishes 2021 Integrated Annual Report March 31, 2022 |
Source:
p. 51
The Agnew Gold Mining Company Proprietary Limited (AGMC), was incorporated in Australia in 2001 as the legal entity holding and conducting mining activity on the Agnew mineral leases. Gold Fields holds 100% of the issued shares of AGMC through its 100% holding in the issued shares of Orogen Holding (BVI) Limited.
Deposit Type
- Vein / narrow vein
- Orogenic
Source:
Summary:
Agnew is situated in the northern portion of the Norseman-Wiluna Greenstone Belt of the Yilgarn Craton, Western Australia. Locally, the belt comprises a sequence of mafic to ultramafic volcanics and associated interflow sediments, which were folded to form the Lawlers anticline.
The mafic and ultramafic volcanics of the Lawlers anticline are unconformably overlain by a sequence of clastic sediments comprising the Scotty Creek formation. The sedimentary rocks were metamorphosed to lower greenschist facies, comprising conglomerates and very fine to very coarse-grained pebbly sandstones and siltstones.
The Agnew deposits are broadly hosted by the intersections between various structures and the relative stratigraphy. Gold mineralisation largely occurs in quartz veins in the sedimentary units of the Scotty Creek formation.
Orogenic greenstone gold deposits (hydrothermal) are hosted in several different styles of lodes. Although all Agnew deposits broadly occur at the intersections between structures and stratigraphy, there are subtle differences in alteration and mineralisation that are controlled in part by the local host rock chemistry. Mineralisation zones are discontinuous with short range predictability.
Mining Methods
- Sub-level stoping
- Longhole open stoping
- Paste backfill
Source:
Summary:
Agnew operates two underground mines, namely Waroonga and New Holland, now amalgamated into the Agnew One Mine Complex. At Waroonga, ore is sourced from the Waroonga North, Kath, Fitzroy Bengal Hastings (FBH), Main and Kim lodes, accessed via declines. New Holland mining occurs in four primary areas: Sheba South, Sheba, Cinderella and Himitsu. These areas are accessed via declines.
The primary mining method at Waroonga is long-hole sublevel stoping with paste fill. The New Holland mining method depends on the geometry of the ore structure with the primary method being long-hole open stoping.
Flow Sheet:
Source:
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
|
|
600 kW
|
1
|
Ball mill
|
|
|
1.2 MW
|
1
|
Ball mill
|
|
|
1.1 MW
|
1
|
Summary:
Agnew (EMU) Processing Plant include primary 600kW Jaw crusher and two stage ball milling circuit consists of closed primary ball mill (1.2 MW) and closed secondary ball mill (1.1 MW)
Processing
- Gravity separation
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Centrifugal concentrator
- Agitated tank (VAT) leaching
- Carbon in pulp (CIP)
- Elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Source:
Summary:
The Agnew processing plant consists of a three-stage crushing circuit, two stage in-series ball milling circuit with two Knelson gravity concentrators, an in-line leach reactor and gravity electrowinning circuit. The carbon in pulp (CIP) circuit consists of air agitated Pachuca tanks, followed by a pressure Zadra elution circuit with carbon generation.
The CIP process involves mixing milled ore with lime and water to form a 45% solids slurry with a pH of approximately 10. A cyanide solution is used to extract gold (Au) from the slurry.
Carbon is added to the solution to capture gold via adsorption. The gold is then recovered from the carbon under high temperature and pressure using sodium hydroxide and sodium cyanide. Gold is plated onto stainless steel mesh via a process of electrowinning.
The primary waste product from the process is a slurry (tailings) containing reject fines, process chemicals and cyanide residues with an elevated pH. This tailings slurry is deposited into TSF3 (Redeemer In-pit Tailings Facility) which has been active since May 2004.
Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Recovery Rate, %
| 95 | 94.6 | 94.2 | 94.2 | 94.4 | 93.6 | 94.8 |
Gold
|
Head Grade, g/t
| 5.8 | 5.8 | 5.7 | 6.49 | 6.5 | 6.5 | 6.4 |
Production:
Commodity | Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Gold
|
koz
| 251 ^ | 223 | 233 | 219 | 238 | 241 | 229 |
All production numbers are expressed as metal in doré.
^ Guidance / Forecast.
Operational Metrics:
Metrics | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Total tonnes mined
| 1,941 kt | 2,044 kt | 1,961 kt | 1,955 kt | 1,905 kt | 1,983 kt |
Ore tonnes mined
| 1,048 kt | 1,294 kt | 1,284 kt | 1,216 kt | 1,174 kt | 1,208 kt |
Waste
| 893 kt | 750 kt | 678 kt | 739 kt | 731 kt | 774 kt |
Plant annual capacity
| 1.35 Mt | 1.3 Mt | 1.3 Mt | 1.3 Mt | 1.3 Mt | 1.3 Mt |
Tonnes processed
| 1,254 kt | 1,357 kt | 1,231 kt | 1,178 kt | 1,235 kt | 1,176 kt |
Reserves at December 31, 2021:
Mineral Resources cut-off for underground 2.2 – 4.1 g/t
Mineral Resources cut-off for open pit 0.76 – 0.93 g/t
Mineral Reserves cut-off for fresh ore 2.6 – 4.6 g/t
Mineral Reserves cut-off for oxide ore 0.85 – 1.04 g/t
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
Stockpiles
|
13 kt
|
Gold
|
8.01 g/t
|
3 koz
|
Proven
|
In-Situ (UG)
|
6 kt
|
Gold
|
5.47 g/t
|
1 koz
|
Proven
|
Total
|
19 kt
|
Gold
|
7.2 g/t
|
4 koz
|
Probable
|
In-Situ (OP)
|
408 kt
|
Gold
|
3.3 g/t
|
43 koz
|
Probable
|
In-Situ (UG)
|
4,712 kt
|
Gold
|
6.37 g/t
|
966 koz
|
Probable
|
Total
|
5,120 kt
|
Gold
|
6.13 g/t
|
1,009 koz
|
Proven & Probable
|
Stockpiles
|
13 kt
|
Gold
|
8.01 g/t
|
3 koz
|
Proven & Probable
|
In-Situ (OP)
|
408 kt
|
Gold
|
3.3 g/t
|
43 koz
|
Proven & Probable
|
In-Situ (UG)
|
4,718 kt
|
Gold
|
6.37 g/t
|
967 koz
|
Proven & Probable
|
Total
|
5,138 kt
|
Gold
|
6.13 g/t
|
1,013 koz
|
Measured
|
Stockpiles
|
13 kt
|
Gold
|
8.01 g/t
|
3 koz
|
Measured
|
In-Situ (UG)
|
108 kt
|
Gold
|
5.82 g/t
|
20 koz
|
Measured
|
Total
|
121 kt
|
Gold
|
6.05 g/t
|
24 koz
|
Indicated
|
In-Situ (OP)
|
2,364 kt
|
Gold
|
2.88 g/t
|
219 koz
|
Indicated
|
In-Situ (UG)
|
9,756 kt
|
Gold
|
6.56 g/t
|
2,059 koz
|
Indicated
|
Total
|
12,120 kt
|
Gold
|
5.85 g/t
|
2,278 koz
|
Inferred
|
In-Situ (OP)
|
751 kt
|
Gold
|
3.55 g/t
|
86 koz
|
Inferred
|
In-Situ (UG)
|
6,888 kt
|
Gold
|
4.64 g/t
|
1,027 koz
|
Inferred
|
Total
|
7,639 kt
|
Gold
|
4.53 g/t
|
1,112 koz
|
Total Resource
|
Stockpiles
|
13 kt
|
Gold
|
8.01 g/t
|
3 koz
|
Total Resource
|
In-Situ (OP)
|
3,116 kt
|
Gold
|
3.04 g/t
|
305 koz
|
Total Resource
|
In-Situ (UG)
|
16,752 kt
|
Gold
|
5.77 g/t
|
3,106 koz
|
Total Resource
|
Total
|
19,880 kt
|
Gold
|
5.34 g/t
|
3,414 koz
|
Commodity Production Costs:
| Commodity | Units | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
All-in sustaining costs (sold)
|
Gold
|
USD
|
1,164 / oz†
|
1,017 / oz†
|
1,152 / oz†
|
1,026 / oz†
|
977 / oz†
|
971 / oz†
|
959 / oz†
|
All-in costs
|
Gold
|
USD
|
1,308 / oz†
|
1,053 / oz†
|
1,152 / oz†
|
1,026 / oz†
|
977 / oz†
|
971 / oz†
|
959 / oz†
|
^ Guidance / Forecast.
† Net of By-Product.
Financials:
| Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Capital expenditures (planned)
|
M USD
| 97 | | | | |
|
|
Growth Capital
|
M USD
| | 32 | 9 | 41 | |
|
|
Sustaining costs
|
M USD
| | 56.3 | 43 | 35.5 | |
|
|
Capital expenditures
|
M USD
| | 88.2 | 52 | 76.1 | 73 |
74
|
70
|
Revenue
|
M USD
| | 402 | 411.5 | 304.6 | 301.1 |
302.6
|
285.4
|
Operating Income
|
M USD
| | | | | |
|
67.8
|
Gross profit
|
M USD
| | | | | |
|
144.9
|
Heavy Mobile Equipment as of July 14, 2014:
Source:
p.39
HME Type | Model | Quantity |
Drill
|
Atlas Copco
|
2
|
Drill
|
|
2
|
Jumbo
|
Sandvik
|
2
|
Jumbo
|
Sandvik
|
2
|
Loader
|
Caterpillar
|
4
|
Loader
|
Caterpillar
|
4
|
Truck (underground)
|
Atlas Copco
|
8
|
Truck (underground)
|
|
4
|
Mine Management:
Job Title | Name | Phone | Email | Profile | Ref. Date |
Alternate Underground Manager
|
Nick Tait
|
|
|
|
Apr 6, 2022
|
General Manager
|
Jason Sander
|
+61 (0) 8 9088-3801
|
jason.sander@goldfields.com.au
|
|
Apr 6, 2022
|
Maintenance Superintendent
|
Neil Freebury
|
|
|
|
Apr 6, 2022
|
Mobile Maintenance Superintendent
|
Jim Innes
|
|
|
|
Apr 14, 2022
|
Processing Manager
|
Tristan Freemantle
|
+61 (0) 8 9088 3822
|
tristan.freemantle@goldfields.com.au
|
|
Apr 14, 2022
|
Underground Mine Manager
|
Karen Davtyan
|
|
|
|
Apr 6, 2022
|
Staff:
Employees | Year |
605
|
2021
|
605
|
2020
|
605
|
2019
|
605
|
2018
|
605
|
2017
|
620
|
2016
|
Corporate Filings & Presentations:
News: