Odysseus project is a low-cost nickel sulphide redevelopment project. Image courtesy of Western Areas Ltd.
The mine will deliver first nickel concentrate by the second quarter of 2023. Image courtesy of Western Areas Ltd.
The Odysseus redevelopment project will include the refurbishment of the existing Cosmos processing plant. Image courtesy of Western Areas Ltd.
Existing infrastructure at the site includes buildings and offices and a 520-room accommodation village. Image courtesy of Western Areas Ltd.

The Odysseus project is a long-life, low-cost nickel sulphide redevelopment project in Western Australia.

Discovered in 2010, Odysseus is among the most recent finds in the Cosmos nickel operations region. It is also among the few nickel sulphide projects that will enter production to meet the rising demand for nickel used in electric vehicle (EV) batteries.

The mine is 100% owned by Western Areas, which acquired it from Cosmos Nickel Operations in October 2015. A definitive feasibility study (DFS) for the project was completed in October 2018, confirming a mine life of ten years with a total production of up to 130,000t of nickel concentrate.

The estimated cost for the redevelopment of the mine is approximately A$299m ($212m).

The redevelopment project was commenced in January 2019. The first nickel concentrate production at the mine is anticipated by the second quarter of 2023.

Odysseus mine location

The Odysseus project is situated on a granted mining lease in the Cosmos Nickel Complex, which is 30km away from Leinster.

The Cosmos complex lies in the Leinster-Wiluna nickel camp, which comprises deposits such as Cliffs, Mt Keith, Perseverance, and Honeymoon Well.

Odysseus project reserves

Odysseus south is estimated to contain probable ore reserve of 4.4Mt graded at 1.9% of Ni containing 85,620t as of June 2019. Odysseus north is estimated to contain probable ore reserve of 3.6Mt graded at 2.2% of Ni containing 78,900t.

The AM6 deposit contains indicated and inferred resource of 2.0Mt graded at 2.6% Ni containing 53,000t.

Odysseus mine geology

The Odysseus deposits are situated 1,000-1,100m below the ground. The Odysseus south orebody extends 360m in strike length with an average thickness of 62m while the Odysseus north orebody lies 100m north of the south orebody and at a depth of 1,000m-1,075m below the surface.

Both the orebodies occur in the same mineralised trend similar to that of the mine’s Alec Mairs 5 (AM5) and AM6 deposits. The entire mine’s mineralogical properties are identical to that of AM5.

The Odysseus Massive deposit comprises stringer to large sulphide veins located just below the Odysseus north. It includes several distinct lenses with the largest being 100m in strike length.

Mining at Odysseus

The nickel project aims to mine an ore reserve of 8.1Mt at a nickel grade of 2.0%.

The primary mining method at the project will employ single-lift long-hole open stoping. The paste fill will be accessed through transverse ore drives on a cross-cut spacing of 50m.

Mining of the north and south orebodies will be carried out in a top-down, centre-out sequence. The top-down approach along with quicker ramp access will allow early access to the ore.

A new single ramp decline beginning from the AM5/6 decline development will provide access to Odysseus.

The project will employ the latest technology to further improve safety and operational efficiency while reducing costs. A fibre-optic network will be incorporated to provide Wi-Fi connection for controlling semi-autonomous and fully autonomous loaders, production drills and related equipment.

A mine control room will be set up to monitor and control pumping, paste filling, refrigeration, ventilation, and mobile fleet activity. It will also supervise the location of personnel and equipment, and send the real-time feedback to the ventilation on demand (VOD) system. The data will be used to optimise the power supply and ensure the circulation of chilled air in the appropriate areas. Additionally, the mine control room will monitor and remotely control the shaft systems and related materials handling system.

Processing details

The existing Cosmos processing plant will be revamped to increase the mill throughput from 450 kilotonnes per annum (ktpa) to 900ktpa to enable the processing of ore from the Odysseus deposits. The plant is expected to reach a capacity of 1Mtpa with further debottlenecking.

The plant expansion will involve the installation of a secondary crusher and new conveyors. The existing grinding mills will be reconfigured and flotation capacity will also be increased.

The Cosmos plant’s design involves a conventional sulphide processing route utilising a traditional grinding and flotation technology for producing concentrate.

The mined ore will be fed through a conveyor from the production shaft head frame to the surface stockpile. The ore will then be transported to the run-of-mine (ROM) bin via a front-end loader and fed to the mill.

The nickel concentrate will be either trucked to the local smelter or exported via the Port of Geraldton in Western Australia.

Odysseus project infrastructure

Existing infrastructure at the site includes site buildings and offices, a 520-room accommodation village, access roads, airstrip, power lines, communications and water supply infrastructure.

The Cosmos early works programme includes the partial refurbishment of the accommodation village, safety infrastructure upgrades, refurbishment of existing water management ponds and waste dump dam along with the design and construction of new water management ponds. A dewatering piping network supply will be installed and a temporary diesel power station will also be set up.

Construction the twin declines started in September 2020. Development of lateral and vertical ventilation is currently underway while the DORA vent rise and the development of the mid-shaft access decline were completed. Completed works include pilot hole drilling for two new vent rises. The mine development also has the provision for a refrigeration plant.

A concrete batch plant facility was commissioned in the first half of 2020 to provide concrete for civil works at the project site.

The site is expected to receive power from a third-party power supplier and fuel from Western Areas. A new 13km-long lateral gas spur line is expected to be constructed adjacent to the existing lateral spur line, which links the Cosmos power plant and the Goldfields gas pipeline (GGP).

Contractors involved

GR Engineering Services won a contract to provide the design and engineering works for the expansion of the plant.

Barminco was awarded a A$200m ($145.6m) development and production contract in September 2020. It previously completed rehabilitation works at the mine.

Piran Mining was contracted for mine planning and optimisation. SRK Consulting is the provider of geological model services.

KCSA Geomechanics and Golders are responsible for geotechnical engineering services, while Itasca Australia won a contract to conduct geotechnical modelling and geotechnical peer review.

The Odysseus project team also includes Dempers & Seymour (mining rock mass modelling), RSV (shaft engineering and design), and Outotec (paste fill engineering, plant design and testing works).

OZ Vent is responsible for ventilation works and ALS Metallurgical Services is conducting metallurgical test work.