The Savage River magnetite deposit lies within and near the eastern margin of the Proterozoic Arthur Metamorphic Complex in north western Tasmania. This complex is exposed along a northeastsouthwest trending structural corridor, the Arthur Lineament, which separates Proterozoic sedimentary rocks to the northwest from a variety of Palaeozoic rocks to the southeast.

The magnetite deposits at Savage River represent the largest of a series of discontinuous lenses that extend in a narrow belt for some 25 kilometres south of the Savage River Township. The deposit is subdivided into sections on the basis of areas that have been mined. The areas are referred to as North Pit, South Lens, Centre Pit, Centre Pit Southern Extension and South Deposit.

Magnetite ore is almost entirely enclosed within a highly sheared and strike-faulted belt of mafic and ultramafic rocks specifically serpentinite and talc-carbonate schist. The magnetite ranges in thickness from 40 to 150 metres in width and is termed the Main Ore Zone (MOZ). Narrow (<20metre) lenses and layers also occur in the mafic sequence to the west. The mafic sequence comprises chlorite-calcite albite schist and layered green amphibole chlorite-albite schist.

A suite of late, strongly deformed metabasalt and metadolerite intrusive dykes occur either sub-parallel to or cut obliquely across the MOZ. Vein magnesite occurs adjacent to the MOZ with significant bodies developed in the east at South Lens and at the west in North Pit.

The magnetite ores comprise three volumetrically important groups: pyritic ores, ores associated with serpentine and talc carbonate ores. The ore may be massive, layered, or disseminated and range from being fine-grained to coarsely crystalline. Accessory mineral phases may include talc, tremolite, actinolite, chlorite, epidote, apatite and carbonate in varying amounts. The mineral assemblages preserved at Savage River imply middle to upper greenschist facies metamorphic conditions.

The mine comprises three principal open pits - North, Central and South Pits - Oriented north-south covering a 4km strike length and separated by unmined zones of thin or low grade material. Centre Pit is separated from North Pit by the Savage River which runs through a pillar area left to retain the river channel. The pits average 100-150m in depth - the proposed cut back and extensions will deepen them by up to a further 250m.

Mining activities in the open pit involve the use of conventional off - highway rear-dump trucks and hydraulic excavators, with drilling and blasting being used to prepare the ground ahead of mining. Grade control sampling is conducted on all blast holes within the orebody, as well as on selected holes around the periphery.

Processing facilities at Grange Resources' Savage River and Port Latta locations consist of the Primary Crusher, Concentrator, Slurry Pipeline and Pelletising Plant.

Primary Crusher:
Ore from the northern section of the mine is tipped into an Allis Chalmers 54/74 gyratory primary crusher, which is located near the rim of the pit. When the iron ore has been crushed to a maximum size of 200 millimetres, it is transported to the 100,000 tonne capacity crushed ore stockpile at the concentrator via a 1.3 kilometre overland conveyor. Ore from the southern section is crushed in an Allis Chalmers 54/62 gyratory crusher before conveyance to the crushed ores stockpile.

Concentrator:
Crushed ore from the stockpile is reclaimed via a tunnel system and fed into the concentrator. It is initially ground by two Hardinge 9.75 metre x 3.66 metre autogenous grinding mills, then by two Nordberg 8.84 metre x 3.96 metre ball mills. Magnetic separators then separate the magnetite from the gangue and the gangue is pumped to the tailings dam.

Slurry Pipeline:
The concentrate slurry from the concentrator is pumped 83km through a 229 millimetre internal diameter slurry pipeline to the pellet plant at Port Latta - transportation time is approximately 14 hours.

Pelletising Plant:
At Port Latta, filtered concentrate is formed into pellets (with bentonite as a binder) and fed to one of the five Midland-Ross vertical shaft pellet furnaces where they undergo approximately 4.5 hours of heat- induced processing. Finished pellets are screened to remove excess fine and coarse material then transferred by conveyor and a rail-mounted traveling/slewing stacker onto the finished product stockpile to cool and await shipment.