Mineralogical investigation and preliminary beneficiation tests for upgrading the Hudenisht nickeliferous lateritic ore

The nickeliferous iron ore of Hudenisht is located in the Pogradec area, Albania. It is developed in layers above altered ophiolite and is covered by limestone of the Upper Cretaceous. The ore was characterized through XRD, ore microscopy and SEM analysis and found that the main mineral phases are hematite, goethite and chromite, with chlorite (clinochlore, nimite), lizardite, calcite and spinel as minor phases. The main Ni-bearing phase is nimite, which appears mainly in the groundmass of the ore. The chemical analysis through XRF showed that it is a lowgrade nickel ore (about 0.8% NiO) with Fe2O3 (74%) as the most abundant constituent. The ore was upgraded through physical beneficiation processes, namely gravimetric and magnetic separations. The received samples were homogenized, crushed to -8 mm and the product was sieved following the wet sieving procedure to obtain four size fractions, i.e. −8+4 mm, −4+1 mm, −1+0.250 mm and −0.250+0.063 mm. Each fraction was subjected to upgrading and the chemical analysis through XRF showed that the best results among the two processes were obtained through the gravimetric separation. It is observed that the float products are richer in nickel mainly in finer size fractions