The NiWest resources are of typical geometry found with nickel laterite deposits which are generally shallow, flat lying zones of mineralised lateritic clays. All of the mineralisation is located between surface and 60 metres. The assumed mining method is via standard open pit methods, and to be mostly free digging with conventional excavators and rigid haul trucks to deliver ore to surface.
The mine schedule used in the study assumes higher strip ratios in the first five years, averaging 9:1 as higher grade ore is sourced preferentially. The average strip ratio for life of mine reduces to 6.9:1 whereby mined lower grade stockpiled ore is utilised in the later stages of the project.
The current mining schedule determined that ore is sourced from only three project areas, Hepi, Eucalyptus and Mt Kilkenny, The mining plan as determined is based on grade and distance from the plant and includes a total cost of $147 million for haulage of ore from Hepi and Eucalyptus projects to the proposed plant site at Mt Kilkenny. Further detailed optimisations will be undertaken to identify cost benefits that can be adopted to improve the model by scheduling high grade ores from other NiWest project areas.