On 19 January 2024, NGX Exploration Limited, a wholly owned Malawian subsidiary of NGX was issued with Retention Licence (RL) Number (RTL0033/24) which covers 5.7km2.
NGX formally became the registered holder of the Malingunde Natural Graphite Project upon the issue of a new Retention Licence.
Contractor | Contract | Description | Ref. Date | Expiry | Source |
Electricity Supply Corporation Of Malawi Limited (ESCOM)
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Power supply
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Power at site will be sourced from the local grid system with additional power provided via diesel generator located onsite as required.
The Malawi Electrical Supply Corporation (ESCOM) plans to construct a 132/11kV substation near Bunda, just 10km to the east of Malingunde which will be linked to the national grid.
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Apr 12, 2023
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unawarded or unknown
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Mining
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A contract mining strategy was selected for the initial eight years to mitigate project risk.
Contractor mining covering load and haul, ore rehandling, haul road development and maintenance, stockpile management and associated fleet maintenance.
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Apr 12, 2023
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8
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Summary:
The graphite mineralisation occurs as multiple bands of graphite gneisses, hosted within a broader Proterozoic paragneiss package. In the Malingunde and Lifidzi areas specifically, a deep tropical weathering profile is preserved, resulting in significant vertical thicknesses from near surface of saprolite-hosted graphite mineralisation.
Malingunde occurs in a topographically flat area west of Malawi’s capital known as the Lilongwe Plain and a deep tropical weathering profile is preserved. A typical profile from top to base is generally soil (“SOIL” 0-1m) ferruginous pedolith (“FERP”, 1-4m), mottled zone (“MOTT”, 4-7m), pallid saprolite (“PSAP”, 7-9m), saprolite (“SAPL”, 9-25m), saprock (“SAPR”, 25-35m) and fresh rock (“FRESH” >35m).
Dimensions
The Malingunde Deposit comprises 4,500 m strike length of shallowly north-east dipping, northwest striking graphitic gneisses. The mineralised package has up to six separate sub-parallel zones of graphite gneiss with cumulative across strike widths averaging 120 m and locally exceeding 200 m. The Msinja Deposit has a strike length of approximately 1.0 km with about five parallel zones of mineralisation. Across strike cumulative widths range between 40 and 100 m. The depth extent of the MRE is approximately 50 m although the mineralisation is believed to extend considerably deeper.
Reserves at June 30, 2024
Ore Reserves are reported at a 6.75% total graphitic carbon (‘TGC’) lower cut-off grade for saprolite and between 9.5% and
11.0% for saprock.
Mineral Resources Estimate is reported at a 4.0% TGC cut-off.
Mineral Resources are reported inclusive of Mineral Reserves.
Category | Tonnage | Commodity | Grade | Contained Graphite |
Proven
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3.1 Mt
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Graphite
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9.5 %
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0.3 Mt
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Probable
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6.4 Mt
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Graphite
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9.5 %
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0.6 Mt
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Proven & Probable
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9.5 Mt
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Graphite
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9.5 %
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0.9 Mt
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Measured
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4.8 Mt
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Graphite
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8.5 %
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0.4 Mt
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Indicated
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32.3 Mt
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Graphite
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7.2 %
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2.3 Mt
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Inferred
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20.6 Mt
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Graphite
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7.3 %
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1.5 Mt
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Total Resource
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57.7 Mt
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Graphite
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7.4 %
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4.2 Mt
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Summary:
The proposed mining method is a conventional truck and shovel mining operation. Free dig mining is considered appropriate for this style of shallow, saprolite-hosted graphite mineralisation. This methodology is used throughout the region for open pit mining operations and is a robust, easily implementable approach.
Zero dilution factor was assumed and is warranted because the majority of the high-grade production target mineralisation is bounded by lower grade mineralisation, and, the free digging, non-blocky nature of the material would result in no displacement by blasting. An allowance of 2% ore loss was applied to account for mining inaccuracies.
A contract mining strategy was selected for the initial eight years to mitigate project risk. An owner-operator model is adopted from Year 9 onwards.
The proposed mining method requires conventional mining infrastructure including but not limited to mining equipment workshop, fuel & oil storage facilities, wash bay, offices, lunch and ablution facilities and a first aid room. These are to be supplied by the mining contractor.
As there is no anticipated requirement for blasting, no infrastructure is required for explosives storage.
The deposit is planned to be mined on 2.5m high benches to maximise mining selectivity and therefore minimise dilution.
A minimum mining width of 20m was used for all pit designs.
The mine schedule is based on achievable production rates for the specified size of mining fleet with only a single shift per day required.
The risk around any geotechnical uncertainty is mitigated by:
• The pits are relatively shallow, being a maximum of ~30m below surface.
• Sensitivity to slope angles was assessed during the optimisation phase and showed the deposit discounted value was insensitive (less than -4%) to changes in slope parameters.
• The nature of the deposit and the small scale and low strip ratio of the mining stages will enable access to other areas of the deposit in the event a mining area is inaccessible.
There is significant opportunity to increase the mine life beyond 16 years by processing lower grade material from the large resource base, or by discovering additional high-grade resources within reasonable trucking distance to the proposed processing plant.
The total Production Target of 9.5Mt run-of-mine (to produce approximately 830kt of concentrate) is underpinned by Proved Ore Reserves of 3.1Mt (32%) and Probable Ore Reserves of 6.4Mt (68%).
A schedule was developed that progressively mines material from the northern-west zones 1 and 2, then the central zones 3 and 4 and finally the south-east zone 5. A three month pre-strip of 190kt of waste is required in order to provide sufficient material to construct the initial TSF. The life of mine strip ratio is 1:1 waste:ore including the capitalised pre-strip.
Comminution
Crushers and Mills
Type | Model | Size | Power | Quantity |
Pebble crusher
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1
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Sizer
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1
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Regrind
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1
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Processing
- Crush & Screen plant
- Wet Screening
- Dry Screening
- Attrition
- Flotation
- Dewatering
Summary:
The design of the processing plant is based on the test-work and best practice in similar operations. Importantly, the process requires no primary crushing or grinding of the ore, a material advantage over hard-rock graphite deposits. The high-grade feed stock of 9.5% TGC over the life of the project assists in achieving the very low processing costs.
The basic flowsheet is summarised below:
- The plant feed will be delivered from the ROM run-of-mine stockpile (ROM) by front-end-loader (FEL) to the grizzly and ROM bin.
- Material is passed through a mineral sizer for primary size reduction.
- Plant feed at 100% -20 mm is processed through a scrubber charged with steel media.
- The scrubber discharge slurry is passed through a 10 mm screen with a small quantity (0-15%) oversize being directed to a small pebble crusher.
- The scrubber undersize is pumped to the rougher flotation section for processing. Rougher tailings are pumped to the tailing’s thickener.
- Rougher concentrate undergoes a polishing regrind.
- The ground concentrate undergoes cleaner flotation stages with the cleaner concentrate split into coarse and fine fractions at 180 µm.
- Attritioning on the coarse and fine fractions followed by three stages of recleaner flotation.
- The final concentrate fractions +180 µm (+80 mesh) and -180 µm (-80 mesh) streams streams are combined and thickened.
- The concentrate is dewatered using a plate and frame filter and air blow and membrane squeeze steps.
- The filtered concentrate is dried using a flash dryer.
- Dried product is screened and bagged for despatch and sale.
Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Graphite
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Recovery Rate, %
| 90 |
Graphite
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Head Grade, %
| 9.5 |
Graphite
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Concentrate Grade, %
| 97 |
Summary:
Water is relatively plentiful in the immediate area and the project will be able to source sufficient water from within the project area, predominantly as part of the pit dewatering requirements.
The baseline work for the hydrogeological studies indicates an approximately uniform hydrogeological environment, with boreholes producing between 1-2 m3/h. However, two of the boreholes, have sustainable yields in excess of 5 m3/h. The numerical modelling work has shown that for the pits, the cone of drawdown is at a maximum extent at the end of mining period (16 years) and recovers rapidly thereafter. After year 16, the residual drawdown is below 1m, with an aerial extent which decreases with time, indicating full recovery.
In terms of water balance, it is expected the project will require an additional ~20,000m3 per month during each nine-month dry season for the first two years of operation.
Production
Commodity | Units | Avg. Annual | LOM |
Graphite
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kt
| 52 | 830 |
All production numbers are expressed as concentrate.
Operational metrics
Metrics | |
Annual ore mining rate
| 600,000 t * |
Annual processing rate
| 600,000 t * |
Stripping / waste ratio
| 1 * |
Ore tonnes mined, LOM
| 9.5 Mt * |
* According to 2023 study.
Production Costs
| Commodity | Units | Average |
Site cash costs (produced)
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Graphite
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USD
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319 / t *
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Cash costs
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Graphite
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USD
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396 / t *
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Assumed price
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Graphite
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USD
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1,296 / t *
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* According to 2023 study / presentation.
Project Costs
Metrics | Units | LOM Total |
Initial CapEx
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$M USD
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70.4
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Sustaining CapEx
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$M USD
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31.6
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Pre-tax NPV @ 10%
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$M USD
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171
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After-tax NPV @ 10%
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$M USD
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119
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Pre-tax IRR, %
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40
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After-tax IRR, %
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31
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After-tax payback period, years
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3
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Heavy Mobile Equipment
Fleet data has not been reported.
Personnel
Job Title | Name | Profile | Ref. Date |
Consultant - Costs
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Matt Langridge
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Apr 12, 2023
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Consultant - Costs
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John Riordan
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Apr 12, 2023
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Consultant - Recovery Methods
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Oliver Peters
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Apr 12, 2023
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Executive Director (Development)
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Peter Fox
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Dec 23, 2024
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Exploration Manager
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Sam Moyle
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Dec 23, 2024
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