This article refers to the mineralogical composition and phase transformations of Greek nickeliferous laterites and to their
metallurgical behaviour, during preheating and reduction with carbon monoxide. Transformation of goethite to hematite and
decomposition of chlorite and serpentine, were identified during preheating. Higher iron metallization was achieved for the
ore in which goethite is the main iron mineral and reduction goes up to 95%, whereas it goes up to 50% for the ore in which
hematite is the main iron mineral. The higher reducibility, however, seems to be due to the higher specific surface area of
the goethitic type of ore.