Mozambique

Ancuabe Project

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Categories

Overview

Mine TypeOpen Pit
StageConstruction
Commodities
  • Graphite
Mining Method
  • Truck & Shovel / Loader
Mine Life30 years (as of Jan 1, 2020)

Owners

SourceSource
CompanyInterestOwnership
Triton Minerals Ltd. 100 % Indirect
Triton, through its 100% owned subsidiaries domiciled in the United Arab Emirates, has a 100% economic interest in Grafex Limitada. Grafex is the registered holder of seven exploration licenses in the Cabo Delgado Province of northern Mozambique. The licenses comprise three project areas; the Ancuabe Project, the Balama North Project and the Balama South Project.

Contractors

ContractorContractDescriptionRef. DateSource
MCC International Inc. EPC / EPCM Following a competitive tendering process, Triton signed an Engineering, Procurement and Construction (EPC) contract with MCC International Incorporation Limited (MCC) for the mineral processing facility and other infrastructure for the Ancuabe Graphite Project. Jun 28, 2018

Deposit type

  • Sedimentary

Summary:

The interpreted mineralisation zones (>3% TGC) comprise eight individual lenses. Approximately 70% of the mineralisation is contained in two major lenses (Zones 1 and 2), that range between a minimum of about 2 m up to a maximum of about 15 m in true thickness. The mineralisation roughly strikes towards 070°, dipping on average 20° towards 340° – although the lenses appear to be affected by gentle folding.

The strike extent is roughly 1,100 m and across strike width is roughly 500 m.

The mineralisation outcrops in the south and east and is interpreted up to a maximum depth of about 190 m below surface in the north. The combined thickness of the mineralisation zones is greatest (˜25 m to ˜40 m) in the eastern half of the deposit thinning to the west (˜5 m to ˜20 m).

Reserves at December 31, 2018



Mineral Resources are reported inclusive of Mineral Reserves.
CategoryTonnage CommodityGradeContained Graphite
Probable 24.9 Mt Graphite 6.2 % 1,544 kt
Indicated 31.1 Mt Graphite 6.9 % 2,150 kt
Inferred 15 Mt Graphite 6 % 890 kt
Total Resource 46.1 Mt Graphite 6.6 % 3,040 kt

Mining Methods

  • Truck & Shovel / Loader

Summary:

The mining method selected for the Ancuabe project is open pit mining applying conventional techniques that are commonly practiced in this style of deposit and region. A mining recovery factor of 95% and dilution factor of 10% have been applied in the Ore Reserve Estimate.

Separate optimisations were run for the T12 and T16 deposits, and two optimisations were carried out for T16 to determine the effect of constraining the pit limits to the tenement boundary on the north of the deposit. Both deposits show flat cash curves indicating that the optimisation is Mineral Resource constrained, indicating that the deposits may continue at depth and possibly along strike.

Final pit designs correlate well with optimisation results, however the T16 final design contains 15% less ROM feed than the optimisation shell as a more practical to the tenement boundary constraint was adopted in the pit design.

Depending on the availability of suitable waste materials at T16 additional materials for the Tailings Storage Facility wall and Water Storage Facility wall construction may also be sourced from within the proposed containment areas. Prior to completion of mining operations at T16, pre- strip mining will commence at T12.

It is planned that conventional drill and blast, load and haul, open pit mining will be used to extract the mineralised material. ROM feed will be defined by grade control procedures in the pit, and delivered by truck to the ROM pad located centrally between the T12 and T16 deposits. Waste will need to be classified for its Potential to be Acid Forming (PAF) and be dumped in managed waste dumps adjacent to the open pits. It is planned that mining will be carried out by an experienced earthmoving contractor.

Comminution

Crushers and Mills

Milling equipment has not been reported.

Summary:

The Ancuabe Graphite Project process plant throughput will range from 0.9 to 1.1 Mtpa, to produce up to 60,000 tpa graphite concentrate (variation based on grade). The flowsheet is based on metallurgical testwork undertaken with samples from the T12 and T16 deposits by weathering extent (oxide/transition and fresh). The proposed process plant facilities for the Ancuabe Graphite Project in the DFS comprise: • Run of mine (ROM) pad • Tertiary crushing circuit • Rod mill feed bin and grinding circuit • Rougher flotation • Three stages of attritioning and five stages of cleaner flotation • Concentrate filtration • Concentrate drying, classification and bagging three products • Tailings thickening and storage • Reagents. The mined ore bearing rock will be crushed into a fine material in a tertiary crushing circuit so that the graphite can be removed. Oversize material will be recirculated through the crushers until the required size is reached. The size reduction will be from approximately 600mm to 20mm through the tertiary crushing circuit. The crushed ore is conveyed to the crushed ore bin and fed into the mill feed conveyor. Ore is fed into the rod mill with water, which operates in closed circuit. The screen undersize P95 710-1000 µm is pumped to the flotation circuit and the screen oversize is recycled back to the rod mill via conveyors. Flotation is the process of bubbling air through the milled sand and water slurry so that the graphite, which is lighter than the sand, can be separated off. This is done by adding reagents to the flotation feed (milled “sand”) and mechanically agitating the slurry mixture to produce rougher concentrate (graphite containing product) and rougher tailings (waste). The rougher concentrate is pumped to an attrition mill where the waste attached to the graphite is “knocked off” the edges of the graphite, before being pumped to the Cleaners. There are five stages of cleaning in the Cleaner circuit where the rougher concentrate is further refined and tailings removed. There are three stages of attritioning on the Rougher, Cleaner 1 and Cleaner 2 concentrates prior to next stage flotation. The final concentrate is then filtered, dried and classified into 3 products before being transferred to a bulk graphite holding bins. The three size fractions include: +300 µm, -300+180 µm, and -180 µm. The final concentrate, once classified, is then packaged into bags on site and stored temporarily, for transport from site by trucks. Full bags will be handled using a forklift and pallets. Bagged concentrate products will be stored undercover and loaded either onto trucks or into containers for shipment from site to the Port of Pemba. The minimum shipment will be one container and maximum of approximately 250 containers.

Processing

  • Flotation

Summary:

The Ancuabe Graphite Project process plant throughput will range from 0.9 to 1.1 Mtpa, to produce up to 60,000 tpa graphite concentrate (variation based on grade).

The flowsheet is based on metallurgical testwork undertaken with samples from the T12 and T16 deposits by weathering extent (oxide/transition and fresh). The proposed process plant facilities for the Ancuabe Graphite Project in the DFS comprise:

• Run of mine (ROM) pad
• Tertiary crushing circuit
• Rod mill feed bin and grinding circuit
• Rougher flotation
• Three stages of attritioning and five stages of cleaner flotation
• Concentrate filtration
• Concentrate drying, classification and bagging three products
• Tailings thickening and storage
• Reagents.

The mined ore bearing rock will be crushed into a fine material in a tertiary crushing circuit so that the graphite can be removed. Oversize material will be recirculated through the crushers until the required size is reached. The size reduction will be from approximately 600mm to 20mm through the tertiary crushing circuit.

The crushed ore is conveyed to the crushed ore bin and fed into the mill feed conveyor. Ore is fed into the rod mill with water, which operates in closed circuit. The screen undersize P95 710-1000 µm is pumped to the flotation circuit and the screen oversize is recycled back to the rod mill via conveyors.

Flotation is the process of bubbling air through the milled sand and water slurry so that the graphite, which is lighter than the sand, can be separated off. This is done by adding reagents to the flotation feed (milled “sand”) and mechanically agitating the slurry mixture to produce rougher concentrate (graphite containing product) and rougher tailings (waste). The rougher concentrate is pumped to an attrition mill where the waste attached to the graphite is “knocked off” the edges of the graphite, before being pumped to the Cleaners.

There are five stages of cleaning in the Cleaner circuit where the rougher concentrate is further refined and tailings removed. There are three stages of attritioning on the Rougher, Cleaner 1 and Cleaner 2 concentrates prior to next stage flotation.

The final concentrate is then filtered, dried and classified into 3 products before being transferred to a bulk graphite holding bins. The three size fractions include: +300 µm, -300+180 µm, and -180 µm.

The final concentrate, once classified, is then packaged into bags on site and stored temporarily, for transport from site by trucks. Full bags will be handled using a forklift and pallets. Bagged concentrate products will be stored undercover and loaded either onto trucks or into containers for shipment from site to the Port of Pemba. The minimum shipment will be one container and maximum of approximately 250 containers.

Recoveries & Grades:

CommodityParameterAvg. LOM
Graphite Head Grade, % 6.2
Graphite Concentrate Grade, % 95

Production

CommodityUnitsAvg. AnnualLOM
Graphite kt 60,0001,492
All production numbers are expressed as concentrate.

Operational metrics

Metrics
Stripping / waste ratio 4.6 *
Waste tonnes, LOM 89,323 kt *
Ore tonnes mined, LOM 24,894 kt *
Total tonnes mined, LOM 114,217 kt *
Tonnes milled, LOM 24,894 kt *
* According to 2017 study.

Production Costs

CommodityUnitsAverage
Cash costs Graphite USD 632 / t *  
Assumed price Graphite USD 1,435 / t *  
* According to 2017 study / presentation.

Project Costs

MetricsUnitsLOM Total
Pre-Production capital costs $M USD 99.4
Gross revenue (LOM) $M USD 2,229
EBITDA (LOM) $M USD 1,178
Pre-tax Cash Flow (LOM) $M USD 1,032
After-tax Cash Flow (LOM) $M USD 753
Pre-tax NPV @ 10% $M USD 298
Pre-tax IRR, % 36.8
Pre-tax payback period, years 3.8

Heavy Mobile Equipment

Ref. Date: December 17, 2017

SourceSource
HME TypeModelSizeQuantity
Drill Atlas Copco ROC D7 3
Excavator Volvo EC750 75 t 2
Loader (FEL) Caterpillar 986H 1
Truck (dump) Volvo A40 40 t 12

Personnel

Mine Management

Job TitleNameProfileRef. Date
Chief Operating Officer Adrian Costello LinkedIn Jan 11, 2024
Project Manager Gidião Mbanze LinkedIn Jan 11, 2024

Aerial view:

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