The Savannah sulphide orebody lies within a marginal norite unit, developed at the base of the Savannah Layered Intrusive Complex (SI) which was intruded into a metamorphosed sequence of sedimentary and igneous rocks called the Tickalara Metamorphics.

The Savannah North mineralisation consists of pyrrhotite, pentlandite and chalcopyrite, ranges from disseminated/matrix to stringer and massive sulphide and dips moderately (40-45 degrees) to the north-west. Two main zones of mineralisation, the Upper Zone, has developed on the basal contact of the Savannah North Intrusion (SNI) and the second, the Lower Zone is a consistent remobilised zone of massive sulphide mineralisation.

The mining methods utilised in the LOM plan is in line with the previous operation being a top-down, long hole open stoping mining method utilising paste fill. This mechanised, non-entry method has proven to be a safe, productive mining method at Savannah.

The total global average planned and unplanned stope dilution (i.e. mined material without Resource classification, including fill dilution) proportion within the Mine Plan stope shapes is 22%.

Mining recoveries of 90% were applied to stopes to allow for issues such as local orebody spatial variability and material left behind during remote loading. A mining recovery of 100% was assumed for ore development.

An undiluted stope minimum mining width (MMW) of 3.0 m (true width) was applied to the Savannah Nth mining area. This is achievable based on the sub-level interval of 20 m floor to floor as from knowledge gained in the mining of the Savannah orebody.

Drill and blast assumptions have been based on historical performance at Savannah. Long hole size is 89 mm diameter and drill metres are based on 6 t / drill m including slotting.

The existing fill system will be utilised for paste filling of the Savannah North stopes. A new paste fill hole is planned for the Savannah Nth, to be drilled from the surface via 1570DD. Dump valves shall be installed at intervals of 200 vertical metres to protect the paste line in case of paste blockages. Additionally, a backup hole is planned to be drilled to mitigate the risk of downtime due to unexpected blockages. Where opportunities arise, waste rock will be backfilled into stopes either via a dedicated truck fill pass or by loader. When back filling with a loader, truck tipping bays will be mined and loaders will be used to transfer the waste into the stope with an appropriate stop-log. The study assumes that all stopes are paste filled. A cement strength of 2.7% was assumed for all paste placed.

The Savannah mine is accessed through a conventional ramp (decline) of 1:7 gradient and dimensions of 5.2 mW x 5.8 mH. Primary access to Savannah Nth from the Savannah decline is via a splinter decline from the 1452 mRL, consisting of two ramps, one for vehicle access and a second for a return air drive (RAD). The 1570 mRL drill drive also forms part of the access to the Savannah Nth.

Savannah ore has been successfully treated through SAG mill since commissioning in 2004.

The Savannah processing plant consists of conventional crushing, grinding, flotation, and concentrate handling, producing a bulk nickel-copper-cobalt concentrate for sale to third-party.

The nominal throughput capacity of the Savannah plant is approximately 1.0Mtpa.

The Savannah mine has a long history of concentrate production, sales, recovery, and treatment costs. The assumptions used for the Ore Reserves are based on the recent actuals for these items. No secondary credits have been modelled in the updated Mine Plan, other than from the copper and cobalt included in the NSR calculation. The concentrate produced at the Savannah mine is a “clean concentrate” and does not have any deleterious elements that attract payment penalties.