Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 7 years (as of Jan 1, 2020) |
Latest News | Gascoyne Resources Ltd.: NRW secures Dalgaranga contract extension October 22, 2020 |
Source:
p. 2
Deposit Type
- Porphyry
- Vein / narrow vein
Summary:
The Dalgaranga Gold project is located in the Dalgaranga Greenstone Belt in the Murchison Province of Western Australia. The North-East trending belt consists of high magnesium basalt, tholeiitic basalt, intermediate volcanic, felsic intrusive porphyry, and a volcano-sedimentary sequence dominated by black shale and volcaniclastic lithologies. The Greenstone sequence is intruded by large gabbro complexes in the north (Mt Farmer, Mt Charles) and to the west (Dalgaranga Hill). The stratigraphy has been folded into two regional synforms which plunge in opposite directions separated by a regional fault/shear along the western side of the Mt Farmer gabbro sill. The Dalgaranga Greenstone Belt is intruded by a number of post tectonic granites separated by zones of amphibolite and mafic schists intruded by pegmatites.
Gilbeys deposit
The main body of mineralisation at Gilbeys is hosted by a porphyry - shale / volcaniclastic package and varies from 20 to 110 metres in width. A combined thickness of the main zone and parallel mineralised zones is up to 200m wide. The style of mineralisation at Gilbeys is a quartz pyritecarbonate veined ductile shear system.
The major control on mineralisation at Gilbeys is structure. A major ductile shear hosts the mineralisation, with the ore grade material developing as consistently wide sub parallel lodes in the areas of strongest shearing. A flat and late vein stage is visible in the footwall and ore-zone, these quartz + sulphide veins appear to be variably mineralised.
Golden Wings Deposit
Golden Wings mineralisation is a plunging orebody limited to a short strike length of mineralised shear zone. There are several mineralised shears developed within a 100m wide zone over 450m of east-west mineralised structure. The geometry of the orebody within the broad east west trend, is, dominated by a high grade zone trending 065-070° dipping steeply to the North, slightly oblique to the stratigraphy. A review of the historic Newcrest, Equigold reports and recent Gascoyne Resources drilling shows multiple gold mineralised zones occurring in the following fresh rock types around 100m; sericite chlorite-quartz schists after mafic or sedimentary units, and quartz-pyrite arsenopyrite plunging lodes within biotite sericite-carbonate-pyrite schists.
Summary:
The mining method adopted at Dalgaranga is open pit mining, using conventional truck and excavator mining. The ore is near surface and is generally described as medium grade.
Mining consists of drill and blast, load and haul with 5m to 10m flitches and 20m batters between benches. Mining is carried out by an experienced mining contractor.
The development of the Gilbey’s pit wall included 3 stages of cut-back, with stage 3 being the final (ultimate) pit. The proposed ultimate pit measures approximately 1,560 metres in length by 680 metres wide, extending vertically to a level of 130 metres reduced level (“RL”), and a maximum depth of approximately 290 metres below surface. The east wall of the proposed pit design contains the majority of final ramp access. The proposed development of the Golden Wings pit measures approximately 500 metres in length by 300 metres wide, extending vertically to a level of 300 metres RL, and a maximum depth of approximately 140 metres below surface.
Crusher / Mill Type | Model | Size | Power | Quantity |
Jaw crusher
|
|
|
|
1
|
SAG mill
|
|
|
|
1
|
Summary:
The process flow diagrams (PFD) for the Dalgaranga Feasibility Study (FS) have been developed from the process design criteria (PDC) prepared by Mintrex. The plant design proposed is simple but robust and broadly comprises the following:
• Primary Crushing;
• Crushed Ore Stockpile;
• Grinding and Classification;
• Gravity Recovery;
• Leaching and Adsorption;
• Elution and Electrowinning; and,
• Smelting.
The design of the comminution circuit for the Dalgaranga Gold Project was undertaken by Orway Minerals Consultants (OMC) in Perth, Australia in consultation with Mintrex. They were requested by Mintrex to model a Single-Stage SAG milling circuit (1C SS SAG) as the basis for their design. The SS SAG milling circuit was selected due to its capital cost and maintenance and operability advantages over more complex and capital intensive circuits.
The crushing circuit will be designed with a throughput of 450 tph and availability of 65%, on a 24 hours per day operation. Crushed product will report to an open stockpile, which has a total capacity of 10,000 tonnes.
A buried apron feeder installed in a concrete reclaim tunnel reclaims ore and directly feeds the milling circuit via the mill feed conveyor. An emergency reclaim feeder is also installed in the reclaim tunnel to provide feed to the mill when reclaiming dead ore from the stockpile via front end loader.
The Milling circuit is designed for a throughput of 300tph, operate at 95% availability, and aims to achieve a design grind of 80% passing 90 µm.
Processing
- Gravity separation
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The processing plant was commissioned in May 2018 and consists of crushing and milling using autogenous grinding, gravity recovery, cyanide leaching, carbon absorption and gold recovery. The plant design is considered to be conventional in nature and is currently operating to nameplate specification.
The plant is capable of processing 2.5Mtpa of fresh and 3Mtpa of oxide or transition ore.
Process recoveries are modelled as follows:
- Oxide 93%;
- Transition 93%;
- Fresh above 290RL 92%;
- Fresh below 290RL 87.45%;
These are largely based on the 2016 Feasibility Study with adjustments applied based on existing performance through the plant.
The crushed ore will be conveyed to the milling circuit and further processing into gold
doré from gravity and CIL recovery.
Ore will be transported to the Run of Mine (ROM) pad from the open pit ore bodies at Golden Wings in the first year of operation followed by th ........

Recoveries & Grades:
Commodity | Parameter | 2020 | 2019 | 2018 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  |
Gold
|
Head Grade, g/t
| 0.86 | 0.78 | 0.62 |
- Subscription is required.
Reserves at April 30, 2020:
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
2.4 Mt
|
Gold
|
0.6 g/t
|
45.8 koz
|
Probable
|
13.9 Mt
|
Gold
|
0.9 g/t
|
380.6 koz
|
Proven & Probable
|
16.3 Mt
|
Gold
|
0.8 g/t
|
426.3 koz
|
Measured
|
1.65 Mt
|
Gold
|
0.75 g/t
|
39.7 koz
|
Indicated
|
21.22 Mt
|
Gold
|
0.86 g/t
|
588.6 koz
|
Measured & Indicated
|
22.87 Mt
|
Gold
|
0.85 g/t
|
628.3 koz
|
Inferred
|
6.76 Mt
|
Gold
|
0.8 g/t
|
173.1 koz
|
Total Resource
|
29.62 Mt
|
Gold
|
0.84 g/t
|
801.3 koz
|
Commodity Production Costs:
| Commodity | Units | 2020 | 2019 |
Cash costs
|
Gold
|
AUD
|
......
|
......
|
All-in sustaining costs (AISC)
|
Gold
|
USD
|
......
|
......
|
All-in costs
|
Gold
|
AUD
|
...... ^
|
|
^ Guidance / Forecast.
- Subscription is required.
Financials:
| Units | 2020 | 2019 | 2018 |
Revenue
|
M AUD
| ......  | ......  | ......  |
- Subscription is required
Heavy Mobile Equipment as of October 27, 2020:
HME Type | Model | Leased or Contractor |
Backhoe
|
.......................
|
|
- Subscription is required.
Aerial view:
- Subscription is required.