Mineralogy and crystal chemistry of a low grade nickel laterite ore

To acquire understanding of Ni enrichment from laterite ore, the mineralogy and crystal chemistry of a low grade limonite type nickel laterite ore sample assaying 0.97% Ni from Indonesia were studied using optical microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). According to EPMA results, the mineral includes 80% goethite ((Fe, Ni, Al)O(OH)) with 0.87% Ni, 15% silicate minerals with lizardite ((Mg, Fe, Ni)3Si2O5(OH)) and olivine ((Mg, Fe, Ni)2SiO4), and 1.19% Ni, and other minor phases, such as hematite, maghemite, chromite and quartz, and no Ni was detected. The mineralogy of the laterite ore indicates that due to the complicated association of the various phases and the variable distribution of Ni, this refractory laterite ore can not be upgraded by traditional physical beneficiation processes.