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Australia

Cosmos - Odysseus Mine

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Overview

Mine TypeUnderground
StatusCare and Maintenance
Commodities
  • Nickel
  • Cobalt
Mining Method
  • Longhole open stoping
Backfill type ... Lock
SnapshotThe Cosmos Project comprises the development of the Odysseus underground mine focused on the production of nickel concentrate, containing nickel and cobalt metal.

Despite the excellent progress made on project development during the first half of FY24, the review identified several key risks, including a reduction in the life of mine, delays in getting the mine to full capacity to fill the processing plant and further increases in operating and capital costs.

Following a careful and considered ramp down phase, Cosmos entered care and maintenance during June 2024. IGO has preserved the value of Cosmos, and has commenced study works to understand the circumstances under which the Project could restart. Despite the care and maintenance decision, significant milestones were achieved on the project during FY24, including: commenced ore production from mining stopes; commissioned and operated the paste-filling plant; commissioned and operated the processing plant to produce concentrate

Owners

SourceSource
CompanyInterestOwnership
IGO Ltd. (operator) 100 % Indirect
The Cosmos Nickel Project, 100% owned and operated by IGO.

Contractors

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Deposit type

  • VMS
  • Metamorphic

Summary:

Cosmos’ cluster, or ‘camp’ of nickel sulphide deposits, occurs within or adjacent to a local sequence of ~2.7 billion year (Ga) old (Archean age), and now metamorphosed, komatiitic lavas that are part of the Agnew-Wiluna Greenstone Belt (AWGB) of the Kalgoorlie Terrane of the Eastern Yilgarn Craton.

The genetic formation model for the nickel mineralisation is the ‘Kambalda-style’ model where precipitation of nickel sulphides is interpreted to occur in channelised komatiitic lava flows and/or lava tubes. This model proposes two dominant deposit types – Type 1 and Type 2.

‘Type 1’ deposits are interpreted to have formed where the hottest lava in the centre of a lava channel thermally erodes into a sulphidic substrate and massive sulphides accumulate at the channel’s base. This high-grade primary formation style is applicable to the Cosmos, Cosmos Deeps, AM1, AM2, parts of AM5 and the Odysseus Massive zones.

Type 1 deposits are often subject to mobilisation into structural sites when massive sulphide bodies behave plastically or even re-melt under the high metamorphic temperatures and pressures that are generated by local or regional tectonic faulting and/or folding events. The Cosmos Deeps and the Odysseus Massive zone are examples of this remobilisation style.

‘Type 2’ deposits are interpreted to have formed from cooler and slower-flowing lavas than those for Type 1 deposits. In this model, the mineral olivine is envisaged to crystallise from these cooler lavas, with the olivine grains settling to the channel’s base shortly after the precipitation of sulphides. In this model, the coeval sulphides crystallise between the olivine grains, giving rise to a disseminated to ‘matrix’ textured nickel sulphide mineralisation that builds up from the channel base. This style of mineralisation is applicable to the AM5, AM6 and Odysseus disseminated zones at Cosmos.

The sulphide nickel assemblages at Cosmos are ‘high tenor’, meaning that the sulphides are dominated by the nickel-bearing mineral pentlandite (Pe). The sulphide assemblages also contain the sulphide mineral pyrrhotite (Po), with minor amounts of pyrite (Py) and chalcopyrite (Py), and in some pla

The mineralisation typically occurs in association with the basal zone of high magnesium oxide (MgO) cumulate ultramafic rocks.

ODS occurs within the Cosmos ultramafic and is located approximately 1,000-1,100m below surface. The AM5 and AM6 zones are both situated to the south and are thought to be genetically related to Odysseus given they all exhibit similar mineralisation characteristics (grade, tenor and sulphide type)

ODS is an elongated, oblate tubular body that strikes north-south (355°) for over 330m, dips 45° east and plunges -5° to the north. Sulphide mineralisation is best concentrated 20-30m above the footwall and consists of highly disseminated to net-textured pentlandite-pyrrhotite in the central and basal zones and pentlandite-pyrite at the edges of the deposit. A higher-grade central core containing >1.5% Ni can reach a thickness of 65m. The central core is enveloped by disseminated sulphides of lower grade (0.5-1.5% Ni). Sulphide mineralisation bifurcates at the northern end and eventually terminates, due to steeply dipping cross cutting pegmatite dykes that are interpreted to have been intruded along brittle fault structures.

The ODN orebody is located 1,000-1,075m below surface and is interpreted to be the northern continuation of Odysseus mineralisation. The ODN and ODS deposits appear to be bifurcated and offset by northeast striking faults now sealed with pegmatite. The entire ODN orebody is dextrally offset ~60m in relation to Odysseus and the dip is rotated 50° counter-clockwise (now near horizontal).

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityUnitsAvg. Annual
Nickel kt 20
All production numbers are expressed as metal in concentrate.

Operational metrics

Metrics
Annual processing capacity  ....  Subscribe
* According to 2022 study.

Production Costs

CommodityUnitsAverage
Credits (by-product) Nickel USD -0.11 / lb *  
Total cash costs Nickel USD 2.43 / lb * **  
All-in sustaining costs (AISC) Nickel USD 2.63 / lb * **  
C1 cash costs Nickel USD 1.98 / lb * **  
Assumed price Cobalt USD 12 / lb *  
Pre-tax break-even price Nickel USD 4.58 / lb *  
Assumed price Nickel USD 7.5 / lb *  
* According to 2018 study / presentation.
** Net of By-Product.

Operating Costs

Currency2018
UG mining costs ($/t milled) USD  ....  Subscribe
Processing costs ($/t milled) USD  ....  Subscribe
Total operating costs ($/t milled) USD  ....  Subscribe
* According to 2018 study.

Project Costs

MetricsUnitsLOM Total
Pre-Production capital costs $M AUD  ......  Subscribe
Sustaining CapEx $M AUD  ......  Subscribe
Closure costs $M AUD  ......  Subscribe
Total CapEx $M AUD  ......  Subscribe
Gross revenue (LOM) $M AUD  ......  Subscribe
EBITDA (LOM) $M AUD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M AUD  ......  Subscribe
After-tax Cash Flow (LOM) $M AUD  ......  Subscribe
Pre-tax NPV @ 7% $M AUD  ......  Subscribe
After-tax NPV @ 7% $M AUD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Oct 9, 2024
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Aerial view:

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