Name of the Project
Odysseus nickel project.
Location
Odysseus is located on a granted mining lease that is part of the high-grade Cosmos nickel complex, 30 km north of Leinster, in Western Australia.
Project Owner/s
Western Areas.
Project Description
A definitive feasibility study (DFS) has confirmed the project as a robust, ten-year operation producing 130 000 t of contained nickel in concentrate from ore reserves of 8.1-million tonnes at a nickel grade of 2%.
Odysseus will be accessed through a new single ramp decline that starts from the existing AM5/6 decline development. Compared with the central spiral decline proposed in the 2017 prefeasibility study (PFS), the ramp decline from the AM5/6 infrastructure minimises the full-face development required to access the Odysseus orebodies, reducing the development timeframe by six months, compared with that of the prefeasibility study (PFS).
While the existing decline development will need to be rehabilitated to a relatively lower take-off point, since it passes directly through existing AM5 infrastructure, it also creates the option of potentially mining the AM5 and AM6 deposits, which contain an indicated mineral resource of 2.2-million tonnes grading at 2.6% nickel.
No evaluation or study has been completed for the AM5 and AM6 deposits, and any potential benefits do not form part of the Odysseus DFS. Early concurrent and later mining options will form part of further study work.
The primary mining method will be single-lift longhole open stoping with paste fill, accessed through transverse ore drives (west to east) on a 50 m crosscut spacing. The South and North orebodies will be mined in a top-down, centre-out sequence. Compared with the PFS, which had proposed a bottom-up approach, the top-down approach, combined with the quicker ramp access, allows for quicker accessing of the ore.
The existing Cosmos processing plant will undergo a $36-millon expansion and refurbishment to increase mill throughput from its previous nameplate capacity of 450 000 t/y to 900 000 t/y.
Potential Job Creation
Not stated.
Net Present Value/Internal Rate of Return
The project has an estimated pretax net present value, at a 7% discount rate, of $418-million, and internal rate of return of 28% at a $7.50/lb nickel price, with a 3.5-year payback from the start of production.
Capital Expenditure
Preproduction capital expenditure is estimated at $299-million, including contingency.
Planned Start/End Date
First nickel concentrate is scheduled for the December 2022 quarter.
Latest Developments
Western Areas has announced first ore production at the Odysseus project.
“It is an exciting milestone to reach first ore and we now look forward to continuing ore production and construction activities while . . . advancing offtake tenders for new nickel sulphide supply into the Class 1 nickel market,” MD Dan Lougher has said.
The ore will be stockpiled during construction of the concentrator complex, which is due to produce first concentrate in the December quarter of 2022. Western Areas is also assessing options for potential ore tolling arrangements in the short term.
The raise bore back reaming has now worked through 630 m of development at a diameter of 5.7 m, completing Leg 1 of the shaft hoisting and intake air system.
“The raise bore breakthrough is also a key achievement that further derisks project delivery and allows [for] completion of the shaft sub-brace concrete works, as well as remaining surface civil works, associated with the shaft. Importantly, the work was completed without a safety incident, for which credit must be given to the site management team and RUC, the raise bore contractor,” Lougher explains.
Key Contracts, Suppliers and Consultants
GR Engineering Services (process plant design, engineering, associated infrastructure); Piran Mining (mine planning and optimisation); KCSA Geomechanics (geotechnical engineering); Golders (geotechnical engineering); Dempers & Seymour (mining rock mass modelling); Itasca Australia (geotechnical modelling and geotechnical peer review); RSV SA (shaft engineering and design); Outotec (paste fill engineering, plant design and testing); OZ Vent (mine ventilation); ALS Metallurgical Services (metallurgical testwork); Groundwater Resource Management (hydrogeology); Big Dog Hydrogeology (hydrogeology peer review); MYR Consulting (risk assessment); Mining Access Legal and MMTS (tenement management services); SRK Consulting (geological model); Project Support (mining tender and infrastructure cost management); and Project Consultancy Services (power study); and Barmico (development and production contract).
Contact Details for Project Information
Western Areas, tel +61 8 9334 7777, fax +61 8 9486 7866 or email info@westernareas.com.au.