2011 – AusIMM Iron Ore Conference 2011, Perth, WA
The Central Eyre Iron Project (CEIP) area, located on the Eyre Peninsula of South Australia, covers extensive Archaean iron formations that occur as coarse-grained magnetite-bearing gneiss. The cumulative strike length, estimated from aeromagnetic data, is at least 95 kilometres.
The project is located in a grain growing area 185 kilometres west of the existing iron ore and steel making operations of OneSteel at Whyalla. A narrow gauge railway built to transport agricultural products to the deep-water port of Port Lincoln, 175 kilometres to the south, traverses the project area. A number of well-serviced rural townships are located nearby. Current activities include resource expansion drilling, extensive metallurgical test work, community consultation and a Pre-Feasibility Study (PFS) that commenced in April 2010.
The PFS has encompassed the entire Central Eyre Iron Project, comprising the three significant iron occurrences (Warramboo, Kopi and Hambidge) and was completed in early 2011. Extensive testwork programmes and metallurgical modelling confirmed viable process options for the project, using simple off the shelf processing technology.
Pre-concentration by coarse cobbing yielded promising results, and is the key to reducing not only the capital expenditure but also the operating cost, in particular the power cost, which is the highest operating cost component of a magnetite beneficiation plant. The ore is also amendable to High Pressure Grinding Rolls (HPGR) processing. This offers a potential for further reduction of the energy requirements.
Testwork also confirmed that a high grade blast furnace quality concentrate (~68% Fe) can be produced at a relatively coarse grind (P80 of 75 µm), in addition to the possibility of production of Direct Reduction (DR) grade concentrate.