Overview
Stage | Permitting |
Mine Type | Open Pit |
Commodities |
- Vanadium
- V2O5
- Titanium dioxide
- Fe2O3
|
Mining Method |
|
Processing |
- Gravity separation
- Calcining
- Magnetic separation
- Roasting
|
Mine Life | 12.5 years (as of Jan 1, 2016) |
Source:
p. 7
Audalia owns the Medcalf project 100% that comprises of M63/656, E63/1133, E63/1134and E63/1855.
Deposit Type
- Banded iron formation
- Sedimentary
Summary:
The Medcalf Project is located in the Archaean aged Lake Johnston greenstone belt in the Yilgarn Craton. This belt contains komatiite lava flows, subvolcanic intrusions, mafic volcanic rocks, felsic volcanic rocks, banded iron formation and sedimentary rocks. The deposit is hosted by the Medcalf layered sill, which is a flat lying igneous body which has intruded parallel to the enclosing basalts. The sill is comprised of an upper gabbroic zone, a middle pyroxenite zone, with a lower amphibolite zone. Vanadium and titanium have initially been concentrated in a flat lying pyroxenite unit, which has subsequently been further enriched in these metals through weathering and regolith formation.
The Medcalf deposit is hosted by a layered igneous intrusion which was emplaced into the predominantly tholeiitic basalt sequence of the Maggie Hays Formation in the lower part of the Lake Johnston Greenstone belt (~2.9 Ga). The host intrusion is a layered basic sill of the gravity differentiated type. It is comprised of an upper gabbroic zone, a middle pyroxenite zone, with a lower amphibolite zone in the footwall. Three separate zones of vanadium mineralisation have been identified within the project area and named the Vesuvius, Fiji and Egmont prospects. In the Medcalf deposit vanadium and titanium have been concentrated in a pyroxenite unit, which has subsequently been enriched in these metals through weathering and regolith formation. The Medcalf deposit is located within the Gordon anticline, a regional northwest trending anticlinal structure. The Medcalf layered sill has been intruded low in the greenstone succession and mapping places it in the hinge zone of a major, gently north plunging anticline. The host sill and volcanics have been metamorphosed to the almandine amphibolite facies of regional metamorphism.
In the mineralised area the magnetite-rich sequence is deeply weathered, with +60m of saprolite showing vertical zonation of weathering minerals due to progressive weathering. The primary mineralisation is the result of gravity accumulations of oxide phases within the pyroxenite zone of the sill. Primary magnetite rich igneous rocks are extensively weathered and show progressive loss of calcium, sodium, magnesium, silica and sulphur. Mafic and ultramafic mineral assemblages with abundant magnetite and ilmenite in unweathered rocks weather to kaolinite, hematite, goethite and minor clays, while ilmenite remains largely unaffected by weathering. Vanadium and titanium were essentially immobile during weathering and thus preferentially enriched through the removal of other rock constituents. Vanadium is present in the samples as microscopic and submicroscopic constituents of hematite, goethite and several other iron minerals.
Summary:
The pit optimisations were completed using processing costs and metallurgical recoveries as provided in the PFS. A mine schedule was generated from the optimisations with total material movements (ore and waste) and calculated metal grades on a diluted basis.
The mine study was based on parent blocks with dimensions of 20m x 20m x 2m with no sub-ceiling and estimated using ordinary kriging (OK) methodology. The resource block model was converted into a model suitable for use in open pit mine engineering functions such as open pit optimisation, design and production scheduling. Pit designs were then developed and three separate open pits identified.
Following the completion of the pit designs, material inventory was reported for use in the production schedule using revised mining recovery parameters to determine cut-off grades.
A mining production schedule was completed using the optimisation pit shells and resultant pit designs. The mine schedule proposes that Vesuvius Stage 1 is mined first for approximately 8 years. Mining commences at Vesuvius Stage 2 in Year 7 and continues through to Year 13. The Egmont and Fuji deposits then supplement the later part of Vesuvius Stage 1 and continue through to Year 12.
This was purposefully done to defer waste stripping as long as practicable and in doing so, maximise project value. The Medcalf Project has a very low mine total strip ratio of 0.6 (waste: ore tonnes) and a strip ratio of 0.2 during the mining of Vesuvius Stage 1. Vesuvius is higher grade than the other deposits, containing 76% of the overall vanadium metal and 73% of the overall titanium metal in the Mineral Inventory.
An average of 1.85 Mt of material is mined in the first 7 years of operation, with a ramp up from Year 8 for an average of 3.6 Mt over the ensuing 3-year period.
Processing
- Gravity separation
- Calcining
- Magnetic separation
- Roasting
Flow Sheet:
Summary:
The pilot scale testwork was performed at GZRINM piloting facility in Guangzhou, China. Approximately 5.5 tonnes of representative samples were processed in the pilot testwork to validate the optimum process parameters.
The developed process flowsheet consists of comminution circuit, beneficiation circuit, roasting circuit and product separation circuit.
Composite ore is fed to a crushing and milling circuit which grinds material to the optimal size for magnetic separation. A low intensity magnetic separator (LIMS) then produces the first concentrate Fe-V concentrate 1, while the tails proceed to a wet high intensity magnetic separator (WHIMS). Primary concentrate produced by WHIMS is then fed to the flash roasting circuit under reductive environment. The calcine product discharged from the roasting furnace is ground to optimal size before fed to drum magnetic separator. The drum magnetic separator produces the second concentrate Fe- ........

Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
V2O5
|
Recovery Rate, %
| 70.3 |
V2O5
|
Head Grade, %
| 0.56 |
V2O5
|
Concentrate Grade, %
| 98.5 |
Titanium dioxide
|
Recovery Rate, %
| 62.4 |
Titanium dioxide
|
Head Grade, %
| 10.2 |
Titanium dioxide
|
Concentrate Grade, %
| 95 |
Fe2O3
|
Head Grade, %
| 58 |
Projected Production:
Commodity | Product | Units | Avg. Annual | LOM |
V2O5
|
Concentrate
|
kt
| 5.8 | 72 |
Titanium dioxide
|
Concentrate
|
kt
| ......  | ......  |
Vanadium
|
Metal in concentrate
|
t
| ......  | |
Fe2O3
|
|
t
| ......  | |
Operational Metrics:
Metrics | |
Stripping / waste ratio
| 0.6 * |
Waste tonnes, LOM
| 10,351,121 t * |
Ore tonnes mined, LOM
| 18,301,806 t * |
Total tonnes mined, LOM
| 28,652,927 t * |
Annual processing rate
| 1.5 Mt * |
* According to 2016 study.
Reserves at March 9, 2016:
Category | Tonnage | Commodity | Grade |
Indicated
|
23 Mt
|
V2O5
|
0.47 %
|
Indicated
|
23 Mt
|
Titanium dioxide
|
8.5 %
|
Inferred
|
8.8 Mt
|
V2O5
|
0.4 %
|
Inferred
|
8.8 Mt
|
Titanium dioxide
|
8.1 %
|
Total Resource
|
31.8 Mt
|
V2O5
|
0.45 %
|
Total Resource
|
31.8 Mt
|
Titanium dioxide
|
8.4 %
|
Commodity Production Costs:
| Commodity | Units | Average |
Assumed price
|
Fe2O3
|
USD
|
40 / t *
|
Assumed price
|
V2O5
|
USD
|
15,000 / t *
|
Assumed price
|
Titanium dioxide
|
USD
|
2,200 / t *
|
* According to 2016 study / presentation.
Operating Costs:
| Units | 2016 |
OP mining costs ($/t mined)
|
AUD
| 7.13 * |
Processing costs ($/t milled)
|
AUD
| ......  |
G&A ($/t milled)
|
AUD
| ......  |
Total operating costs ($/t milled)
|
AUD
| ......  |
* According to 2016 study.
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2016 Study Costs and Valuation Metrics :
Metrics | Units | LOM Total |
Total CapEx
|
$M AUD
|
......
|
Total OpEx
|
$M AUD
|
......
|
Gross revenue (LOM)
|
$M AUD
|
......
|
Pre-tax Cash Flow (LOM)
|
$M AUD
|
......
|
Pre-tax NPV @ 8%
|
$M AUD
|
......
|
Pre-tax IRR, %
|
|
......
|
Pre-tax payback period, years
|
|
......
|
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Mine Management:
Job Title | Name | Profile | Ref. Date |
.......................
|
.......................
|
|
Oct 23, 2021
|
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Corporate Filings & Presentations:
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