Overview
| Stage | Permitting |
| Mine Type | Open Pit |
| Commodities |
|
| Mining Method |
|
| Mine Life | 24 years (as of Jan 1, 2022) |
Ngualla is Large scale, high-grade deposit with a long mine life and low opex and capex intensity. |
Source:
p. 31
Contractors
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Deposit Type
- Magmatic
- Carbonatite hosted
Summary:
Rare earth and barite mineralisation at Ngualla is magmatic in origin and hosted within the core of the Ngualla Carbonatite. Mineralisation has been residually enriched in the oxide zone at surface through weathering and the removal of carbonate minerals to variable depths of up to 140 m vertically.
High-grade rare earth mineralisation is hosted within the iron oxide and barite-rich weathered zone and above an irregular karstic surface, referred to as the Weathered Bastnaesite Zone. For modelling purposes, upper grade thresholds of 0.69% P2O5 and 13.99% CaO have been used to assist with the definition of Weathered Bastnaesite Zone Mineral Resource subset reported, which has been found through test work to be most amenable to the current metallurgical extraction process.
Summary:
Mining is based on conventional selective mining methods, utilising hydraulic excavators, dump trucks and drill-and-blast, coupled to a ROM stockpile. All the ore is oxidised material categorised as “free dig”, so only the fresh waste rock requires blasting.
Both ore and waste will be excavated in 2.5 m flitches following mark-out by grade control. Ore will be hauled to either the ROM pad skyway and tipped onto a designated ore finger or a designated low-grade stockpile. All mine waste will be hauled directly from the pit and placed onto a designated location of the tailings storage facility (TSF) dam wall; there are no other external waste dumps.
The mining fleet comprises 41-tonne articulated dump trucks (Caterpillar 745) loaded by a 90- tonne excavator (Caterpillar 395). A 30-tonne front-end loader (Caterpillar 980M), which is capable of loading the 41-tonne dump trucks, will be used as back-up for the primary loading unit and also to make up shortfalls in periods where additional material movement is required. Other ancillary support will be supplied by a Cat D9R dozer, Cat 14M grader, and Cat 745 watercart. Maintenance will be conducted on site.
Owner-operated mining was selected as the operating strategy at Ngualla, with the intent of further reviewing potential contract mining offerings during the Front-End Engineering Design (FEED) phase.
The pit and stage designs were based on the slope parameters: Saprolite (21.3°), Mixed ........
Source:
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Flow Sheet:
Summary:
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Projected Production:
| Commodity | Units | Avg. Annual |
|
Total Rare Earth Oxides
|
kt
| 16 |
All production numbers are expressed as concentrate.
Operational Metrics:
| Metrics | |
|
Stripping / waste ratio
| ...... |
|
Annual milling capacity
| ...... |
|
Annual ore mining rate
| ...... |
* According to 2022 study.
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Reserves at October 31, 2022:
Cut-off grade 1% TREO.
| Category | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
17 Mt
|
Total Rare Earth Oxides
|
4.78 %
|
813 kt
|
|
Probable
|
1.5 Mt
|
Total Rare Earth Oxides
|
5.1 %
|
74 kt
|
|
Proven & Probable
|
18.5 Mt
|
Total Rare Earth Oxides
|
4.8 %
|
887 kt
|
|
Measured
|
86.1 Mt
|
Total Rare Earth Oxides
|
2.61 %
|
2,250 kt
|
|
Indicated
|
112.6 Mt
|
Total Rare Earth Oxides
|
1.81 %
|
2,040 kt
|
|
Inferred
|
15.7 Mt
|
Total Rare Earth Oxides
|
2.15 %
|
340 kt
|
|
Total Resource
|
214.4 Mt
|
Total Rare Earth Oxides
|
2.15 %
|
4,620 kt
|
Commodity Production Costs:
| | Commodity | Average | Average |
|
Cash costs
|
Nd2O3+Pr6O11
|
...... &nbs
|
|
|
Assumed price
|
Nd2O3+Pr6O11
|
...... *
|
|
* According to 2022 study / presentation.
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2022 Study Costs and Valuation Metrics :
| Metrics | Units | LOM Total |
|
Closure costs
|
$M USD
|
......
|
|
After-tax Cash Flow (LOM)
|
$M USD
|
......
|
|
Pre-tax NPV @ 8%
|
$M USD
|
......
|
|
After-tax NPV @ 8%
|
$M USD
|
......
|
|
After-tax IRR, %
|
|
......
|
|
After-tax payback period, years
|
|
......
|
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Corporate Filings & Presentations:
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