Overview
Stage | Production |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
Processing |
- Smelting
- Centrifugal concentrator
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Gravity separation
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in leach (CIL)
- AARL elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
|
Mine Life | 2027 |
Source:
p. 19,215
Company | Interest | Ownership |
Evolution Mining Ltd.
|
100 %
|
Indirect
|
Mt Rawdon Operations Pty Ltd.
(operator)
|
100 %
|
Direct
|
Evolution has owned and operated Mt Rawdon since November 2011.
Summary:
The Mt Rawdon gold deposit is a massive intrusive-related low grade gold deposit that exhibits excellent characteristics conducive to low cost mining and treatment. Alluvial gold was first discovered on the hill flanks in 1946 leading to early mining endeavours however the gold grade was too low to be profitable in those times. The gold mineralisation is closely associated with fine disseminated pyrite and base metal sulphides as well as in irregular discrete veinlets within the igneous host rocks. The gold grade is statistically independent of the sulphide percentage of the host however. The host rocks are predominantly rhyodacitic intrusives, breccias and a related volcaniclastic pile, with the orebody dipping moderately to the south west.
Summary:
Mining production is derived from a single open pit, utilising conventional drill and blast, load and haul methodologies, mining 10-15m benches. The operation is scheduled to continue until FY25 at current estimates with a remaining life of mine strip ratio of 2:1.
Flow Sheet:
Crusher / Mill Type | Model | Size | Power | Quantity |
Gyratory crusher
|
.......................
|
42" x 65"
|
|
1
|
Cone crusher
|
.......................
|
|
|
1
|
Cone crusher
|
.......................
|
|
|
1
|
SAG mill
|
.......................
|
28'
|
|
1
|
Ball mill
|
.......................
|
|
|
1
|
Summary:
Crushing plant total capacity: 720tph (two stage crushing)
Primary crushing/grinding plant/machinery:
- Allis Charmers 42/65 superior gyratory.
Secondary crushing/grinding plant/machinery:
- Jaques J65;
- Pre screen with double deck Joest vibrating screen;
- Synton feeder to screen and bypass using an overflow bin for lump;
- Nominal reduction ratio of 5-1 (125mm primary crush to 25mm secondary crush).
Grinding plant equipment:
- Dominion 28’ SAG;
- Nordberg 42/70HG ball mill.
Grinding media:
- High manganese steel, 125mm ball (steel lined SAG mill) 64mm balls (rubber lined ball mill). Grind size 60% -106µm.
Recycle crusher:
- Autofine 736 Cone Crusher (Allis Chalmers).
Processing
- Smelting
- Centrifugal concentrator
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Gravity separation
- Agitated tank (VAT) leaching
- Concentrate leach
- Carbon in leach (CIL)
- AARL elution
- Carbon adsorption-desorption-recovery (ADR)
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Summary:
The Mt Rawdon processing plant consists of primary and secondary crushing, SAG and ball milling, followed by conventional cyanidation leaching. Gold feed is recovered through a gravity circuit prior to the flotation circuit to produce dore gold bars which are sold to the ABC Refinery in Sydney.
Ore treatment/processing method/s:
- Conventional crush-grind-CIL to produce gold dore.
Nameplate capacity of plant: 3.5Mtpa.
Mineral liberation/recovery method: CIL.
Mineral liberation plant/equipment:
- 1 x 1,500m3 leaching tank;
- 5 x 1,500m3 adsorption tanks.
Gravity circuit: Knelson Concentrator 13% of gold recovered by gravity.
Process pumps: Warman 10/12 split casing.
Chemical/reagents used: Air Liquide (oxygen), Unmin (lime), Elgas (LPG), IXIM (HCl, caustic), Orica (cyanide), Jacobi (carbon).
Refining plant/equipment: 8t AARL elution column.
Recoveries & Grades:
Commodity | Parameter | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Gold
|
Recovery Rate, %
| ......  | ......  | ......  | 88.8 | 88.5 | 90.4 |
Gold
|
Head Grade, g/t
| ......  | ......  | ......  | 1.14 | 1.06 | 0.86 |
Production:
Commodity | Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Gold
|
oz
| ...... ^ | ......  | ......  | ......  | 105,053 | 101,331 | 85,002 |
Silver
|
oz
| | ......  | ......  | ......  | ......  | ......  | ......  |
All production numbers are expressed as payable metal.
^ Guidance / Forecast.
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Operational Metrics:
Metrics | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Ore tonnes mined
| ......  | ......  | 3,202 kt | 4,444 kt | 5,005 kt | 3,307 kt |
Waste
| ......  | ......  | 3,404 kt | 4,650 kt | 5.56 Mt | 1.9 Mt |
Tonnes processed
| ......  | ......  | 3,245 kt | 3,241 kt | 3,351 kt | 3,421 kt |
Annual processing capacity
| ......  | ......  | | 3.5 Mt | 3.5 Mt | 3.5 Mt |
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Reserves at December 31, 2020:
Mineral Resource cut-off 0.21 g/t.
Ore Reserve cut-off 0.3 g/t.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
4.26 Mt
|
Gold
|
0.41 g/t
|
56 koz
|
Probable
|
15.82 Mt
|
Gold
|
0.67 g/t
|
342 koz
|
Proven & Probable
|
20.08 Mt
|
Gold
|
0.62 g/t
|
398 koz
|
Measured
|
7.29 Mt
|
Gold
|
0.34 g/t
|
81 koz
|
Indicated
|
32.91 Mt
|
Gold
|
0.6 g/t
|
630 koz
|
Inferred
|
10.47 Mt
|
Gold
|
0.52 g/t
|
175 koz
|
Total Resource
|
50.66 Mt
|
Gold
|
0.54 g/t
|
885 koz
|
Corporate Filings & Presentations:
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Aerial view:
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