The Odysseus deposits are located 1,000-1,100m below surface. Odysseus South spans 360m in strike length, 228m in height and has an average thickness of 62m. Odysseus North lies 100m north of Odysseus South at 1,000-1,075m below surface and spans 380m in strike length, 163m in height with an average thickness of 51m.

The North and South zones occur in the same mineralised trend as AM5 and AM6 and they all appear genetically related. The sulphides are highly disseminated to net-textured, consisting of pentlandite with minor pyrrhotite and pyrite. The broader Odysseus system exhibits mineralogical properties similar to that of the partially mined AM5 deposit.

The Odysseus Massive deposit consists of stringer to massive sulphide veins positioned immediately below Odysseus North at a vertical depth of 1,100m. The deposit comprises a number of different lenses, the largest measuring 100m in strike, up to 5m in height and up to 65m in width. These lenses may be ultimately extended with further resource drilling success. The decision to extend the length of a number of drill holes from the FY17 Odysseus North resource upgrade program into the massive sulphide below yielded very strong results (5.3m @ 15.2% Ni, including 3.4m @ 22% Ni) and confirmed the presence of further massive sulphide potential.

Cosmos Nickel Complex is located 30km north of Leinster and include high grade deposits at Cosmos, Cosmos Deeps, Prospero, Tapinos, AM1, AM2, AM4 and Odysseus North Massive Sulphide, medium grade deposits at AM5 and AM6 and large low-grade Mt Goode deposit.

The primary mining method will be single-lift long-hole open stoping with paste fill accessed via transverse ore drives (west to east) on a 50m cross cut spacing. The South and North orebodies will be mined in a top down, centre out sequence. Compared to the PFS, which had proposed a bottom-up approach, the top-down approach combined with the quicker ramp access enables earlier access to ore.

Average stope size will be 15m wide along strike, up to 29m long across strike and the level spacing is 25m floor to floor, containing up to 30,000t of ore per stope. The LOM plan includes 3.5% unplanned dilution and mining recovery is expected to be 95%. Approximately 11% of the total 8.1Mt Ore Reserve will be produced from ore drive development with the remaining 89% produced from long-hole production stopes. Stopes will be backfilled using paste fill made from tailings recycled from the process plant. Comprehensive paste fill test work demonstrated a suitable high-strength paste backfill can be produced to meet underground mining requirements and maximise extraction, allowing for a top-down mining approach.

The hoisting shaft will be equipped with rope guides and services and has a capacity of 1.1mtpa to accommodate ore and waste. It will be equipped with a mid-shaft loading station (MSLS) and a bottom shaft loading station (BSLS). The MSLS will allow significant savings during the development of Odysseus while the BSLS is being established, allowing for hoisting of material during this period rather than hauling of material via trucks to surface. The MSLS can also be used for the potential future mining of the AM5 and AM6 deposits and provides a backup solution for any temporary inactivity of the BSLS.

At the BSLS, ore and waste will be hauled via 50t trucks to the shaft loading point where the material will be fed through a grizzly containing two rock breakers into a coarse ore storage bin. An apron feeder will then feed the coarse ore to a mineral sizer that reduces feed to a maximum of 150mm from which the material will then travel via an underground short conveyor towards the shaft loading flask. The material will then be fed into two 12.5t skips where it will be hoisted to surface. On surface, ore will be transported via an overland conveyor to the surface stockpile where a loader will feed the ore into the mill. Waste will be dumped via a side tipper approximately halfway between shaft and ROM pad and transported on trucks to the waste dump.

Having conducted benchmarking visits to some of the leading underground mine sites around the world, the Project will incorporate some of the latest technology, to further enhance safety, operational efficiency and reduce costs. Key technologies include fibre-optic backbone to provide all production areas with Wi-Fi sufficient for the control of semi and fully autonomous loaders, production drills and other equipment. A state-of-the-art mine control room will be the real time operational nerve centre, monitoring and controlling ventilation, refrigeration, pumping, paste filling and mobile fleet activity. The system will monitor personnel and equipment location, providing real time feedback to the Ventilation on Demand (VOD) system to optimise power draw and ensuring chilled air is directed to the appropriate areas. The shaft systems and related materials handling system will be monitored via CCTV and controlled remotely via the mine control room.

The Cosmos process plant design is based on a conventional sulphide processing route using traditional grinding and flotation technology to produce a saleable concentrate. Ore mined will be fed via conveyor from the production shaft head frame to the surface stockpile. A front-end loader will then be used to transport ore from the surface stockpile into the ROM bin to feed the mill.