Overview
| Stage | Feasibility |
| Mine Type | Open Pit |
| Commodities |
|
| Mining Method |
|
| Processing |
- Flotation
- Magnetic separation
|
| Mine Life | 14 years (as of Jan 1, 2012) |
There is also an optimised project development option which, at this stage, has only been progressed to pre-feasibility by our JV partners since the completion of the DFS. This would involve a smaller 5mtpa operation within the constraints of existing approvals, mineral resources and ore reserves; and is anticipated to deliver reductions in capital spend from ~A$2.9B down to ~A$1.4B. This alternative case extends the life of mine from 14 years to 28 years for the western zone, and more than 50 years for the total resource (see Project Details below). The 10mtpa DFS completed in 2012 remains the base case for the JV, and the decision as to whether the alternative option is further studied to definitive feasibility will be an issue considered together by the existing joint venture partners and any joining equity investor. |
Source:
p. 16
The Southdown Joint Venture (SDJV) is a joint venture between Grange Resources Limited (70%) and SRT Australia Pty Ltd (SRTA) (30%).
Summary:
The Southdown deposit occupies the core of a gently east plunging, overturned tight isoclinal syncline with a steeply south dipping axial surface. The deposit is offset by moderately northeast dipping dextral reverse faults and subsidiary steeply south-east dipping sinistral faults. Currently the resource extends for 11 kilometres of the 12 kilometre strike length of the deposit, with variable depths ranging from a surface outcrop in the west, to 480 metres below surface in the east.
Summary:
The mine will be an open pit, with modern large scale open pit mining methods employed. Mining will be a conventional hydraulic face shovel and diesel dump truck operation. The shovel size will be 650 tonnes with trucks sized to match (220 tonne payload).
Detailed mine design and schedules for the DFS have been constrained to the ore reserve west of the South Coast Highway. To achieve 10 million tonnes per annum of concentrate production a material movement in the mine averaging 110 million tonnes per annum is required.
Processing Technologies
- Flotation
- Magnetic separation
Flow Sheet:
Summary:
Samples from numerous drilling programs have been used for comprehensive metallurgical test work. Pilot test work has also been completed and the processing flow sheet is finalised. The concentrator design and equipment selections are based on a targeted production rate of 10 million tonnes per annum of premium quality magnetite concentrate. The process flow sheet includes:
- Primary crushing
- Coarse ore stockpile
- AG milling in closed circuit with two-stage screening
- Rougher magnetic separation
- Ball milling in closed circuit with cyclones
- Intermediate magnetic separation
- Fine grinding using IsaMills™
- Hydro-separation
- Cleaner magnetic separation
- Flotation
- Thickened tailings slurry disposal to the Tailings Storage Facility (TSF)
- Thickening of magnetite concentrate
- Transportation of concentrate via a pipeline to the dewatering plant at the Port of Albany.
- Magnetite concentrate dewatering at the port
- Return of filtered water to the mine site for re-use
- Magnetite concentrate storage and out-loading
onto cape size vessels.
Recoveries & Grades:
| Commodity | Parameter | Avg. LOM |
|
Iron (magnetite)
|
Concentrate Grade, %
| 69.5 |
Projected Production:
| Commodity | Units | Avg. Annual |
|
Iron (magnetite)
|
Mt
| 10 |
All production numbers are expressed as concentrate.
Operational Metrics:
| Metrics | |
|
Plant annual capacity
| 10 Mt of concentrate * |
* According to 2012 study.
Reserves at February 23, 2018:
| Category | Tonnage | Commodity | Grade |
|
Proven
|
384.6 Mt
|
DTR
|
35.6 %
|
|
Probable
|
3.1 Mt
|
DTR
|
41.7 %
|
|
Proven & Probable
|
387.7 Mt
|
DTR
|
35.6 %
|
|
Measured
|
423 Mt
|
DTR
|
37.8 %
|
|
Indicated
|
86.8 Mt
|
DTR
|
38.7 %
|
|
Inferred
|
747.1 Mt
|
DTR
|
30.9 %
|
|
Total Resource
|
1,257 Mt
|
DTR
|
33.7 %
|
Commodity Production Costs:
| | Commodity | Units | |
|
Cash costs
|
Iron (magnetite)
|
AUD
|
58.5 / t *
|
|
Assumed price
|
Iron (magnetite)
|
USD
|
125 / t *
|
* According to 2012 study / presentation. (per tonne of concentrate)
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2012 Study Costs and Valuation Metrics :
| Metrics | Units | LOM Total |
|
Initial CapEx
|
$M AUD
|
2,885
|
|
After-tax Cash Flow (LOM)
|
$M USD
|
......
|
|
After-tax NPV @ 10%
|
$M AUD
|
......
|
|
Ater-tax IRR, %
|
|
......
|
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Corporate Filings & Presentations:
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