New Caledonia is the third most important producer of nickel in the world, after Russia and Canada. New Caledonia contains approximately 25% of the world’s known nickel resources. These resources are contained in laterite ore deposits.
Since May 1998, geological studies have been undertaken to understand, describe and evaluate the mineral potential of the Koniambo ore body. The Koniambo massif is 20km long by 5km wide. A mineralization of significant laterite origin occupies around 21km2 of the massif.
The term ‘laterite’ is commonly used to describe the alteration process due to climactic phenomena that generates a concentration of trace elements in the encasing rock (in this case, nickel).
The laterite profile of the Koniambo ore body consists of, summarily: a thin covering of iron-rich duricrust over a layer of limonite which covers a transitional zone ending with a layer of saprolite ore. Present quantities of nickel, cobalt, iron and other oxidised minerals within the laterite profile vary according to depth.
In the preferred exploitation zone, the limonite covering is generally less than 5m thick and the saprolite of commercial value often comes through. The Bilboquet, Manguen and Centre sectors present the ‘measured’ and ‘indicated’ resources as being 75.57 Mt with 2.47% Ni content. The resources necessary to a 25 year long mining plan constitute approximately half of the totality of the massif’s resources (cut-off grade 2.1% Ni).
At the end of 25 years of exploitation, the open pit mine, made up of a series of quarries, will cover an area of approximately 745 hectares.
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Mine and geology
