1. Introduction. Ni-Co laterite ores are derived from the intense chemical weathering of mafic or ultramafic rocks containing Ni-bearing olivine (Golightly, 1981, Freyssinet et al., 2005, Butt and Cluzel, 2013).This process leaches the mobile constituents of the peridotite (Mg, and Si), whereas the immobile components (Fe, Al, Cr, Ni, Mn, Cu, …