Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Gravity separation
- Dry Screening
- Smelting
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 5 years (as of Jan 1, 2020) |
Source:
p. 27
Current registered holders of the tenements are Regis Resources Ltd. Regis Resources Ltd has 100% interest in all tenements.
Summary:
Garden Well is located on the eastern limb of the Erlistoun syncline of the Duketon Greenstone Belt. The gold of the Garden Well Deposit occurs as supergene mineralisation within upper Archaean regolith and as hypogene mineralisation in fresh rock. No significant amounts of gold occur in the transported quaternary clay sequence.
The gold is associated with intensely sheared and folded ultramafic and shale units that have been hydrothermally altered to a silica- carbonate-fuchsite-chlorite-pyrite-arsenopyrite assemblage, and underlying chert units.
The gold mineralisation trends roughly north-south over a distance of 2,100m and dips 50º to 60º east which is sub-parallel to the ultramafic-sediment contact.
The approximate dimensions of the deposit are 2,100m along strike (N-S), 600m across (E-W), and 500m below surface.
Summary:
The mining method assumed in the Ore Reserve study is the same as that currently employed at the Garden Well Gold Mine, which utilises drill and blast, excavator and truck open pit mining. The existing pit has been designed to be developed in a series of progressive cutbacks.
Geotechnical and hydrogeological recommendations have been applied during pit optimisation and incorporated in design with ongoing reviews. No factors are applied to the Measured portion of the deposit. 5% ore-loss has been considered for the Indicated portions of the deposit in the estimation of the Ore Reserve. This is considered consistent with the current reconciliation to production, the style of estimation and experience from Regis’ other Duketon operations which use the same estimation approach, and is consistent with the suitability of earthmoving equipment to the orebody type (moderate grade and wide mineralised zones).
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Gyratory crusher
|
|
|
|
1
|
Cone crusher
|
|
|
|
2
|
Ball mill
|
|
|
|
1
|
Regrind
|
|
|
|
1
|
Processing
- Gravity separation
- Dry Screening
- Smelting
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- Elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The existing Garden Well crushing, grinding and CIL Processing facility will be utilised to treat the Ore Reserve. Based on feasibility testwork, actual data and testwork since the commencement of production broad recovery variations have been reflected in domains applied to the Resource model for use in the Ore Reserve estimation. The resultant average recovery factor of the Ore Reserve is approximately 89% based on final tonnages and grades of ore types.
The Ore Reserve will be processed through the existing conventional crush, grind, carbon in leach (CIL) processing plant located at Garden Well to produce gold doré. In the competent person’s view, the process for this style of mineralisation is appropriate.
Recoveries & Grades:
Commodity | Parameter | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
Head Grade, g/t
| ......  | ......  | 0.92 | 0.94 | 0.87 | 0.9 |
Production:
Commodity | Units | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Gold
|
koz
| ......  | ......  | 112 | 131 | 158 | 151 |
All production numbers are expressed as metal in ore.
- Subscription is required.
Operational Metrics:
Metrics | 2020 | 2019 | 2018 | 2017 | 2016 | 2015 |
Ore tonnes mined
| ......  | 3.2 Mt | 3.8 Mt | 4.3 Mt | 5.6 Mt | 5.2 Mt |
Plant annual capacity
| ......  | 5 Mt | | 5 Mt | | |
- Subscription is required.
Reserves at December 31, 2020:
Resources are reported at cut-off grades of 0.4 g/t Au for open-pit and 1.8 g/t Au for underground.
Reserves are reported at cut-off grades of 0.5 g/t Au for open-pit and 2.1 g/t Au for underground.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
In-Situ (OP)
|
4 Mt
|
Gold
|
0.6 g/t
|
80 koz
|
Probable
|
In-Situ (OP)
|
14 Mt
|
Gold
|
1 g/t
|
450 koz
|
Probable
|
In-Situ (UG)
|
1 Mt
|
Gold
|
3.4 g/t
|
100 koz
|
Proven & Probable
|
In-Situ (OP)
|
18 Mt
|
Gold
|
0.9 g/t
|
530 koz
|
Proven & Probable
|
In-Situ (UG)
|
1 Mt
|
Gold
|
3.4 g/t
|
100 koz
|
Measured
|
In-Situ (OP)
|
9 Mt
|
Gold
|
0.7 g/t
|
210 koz
|
Indicated
|
In-Situ (OP)
|
50 Mt
|
Gold
|
0.8 g/t
|
1,260 koz
|
Indicated
|
In-Situ (UG)
|
1 Mt
|
Gold
|
3.8 g/t
|
140 koz
|
Inferred
|
In-Situ (OP)
|
6 Mt
|
Gold
|
0.7 g/t
|
130 koz
|
Inferred
|
In-Situ (UG)
|
1 Mt
|
Gold
|
3.4 g/t
|
130 koz
|
Total Resource
|
In-Situ (OP)
|
64 Mt
|
Gold
|
0.9 g/t
|
1,600 koz
|
Total Resource
|
In-Situ (UG)
|
2 Mt
|
Gold
|
3.6 g/t
|
280 koz
|
Corporate Filings & Presentations:
- Subscription is required.
Aerial view:
- Subscription is required.