Preliminary study of scandium enrichment in Çaldağ-Manisa lateritic Ni-Co Deposit, Western Anatolia

Abstract

Scandium is one of the most valuable critical metals, with high demand in applications ranging from biomedical research to electronics. Lateritic Ni-Co deposits are considered prime targets for scandium (Sc) exploration because Sc can be concentrated during weathering through residual and secondary enrichment, reaching up to 100 ppm and making it a potential by-product. This study investigates the distribution of Sc in the unweathered parent rocks and various laterite zones within two distinct pits of the Çaldağ lateritic Ni-Co deposit in Western Anatolia. In the Hematite pit, the serpentinite protolith shows an average Sc content of 10.3 ppm, with significant enrichment in the middle-upper limonite zone, reaching up to ~66 ppm. Although this represents a sixfold increase compared to the serpentinite protolith, the maximum Sc concentrations (53.6–65.7 ppm) are relatively low compared to other nickel laterites with by-product Sc potential (~100 ppm). This lower concentration is attributed to the initial low Sc content of the serpentinized peridotite protolith and post-lateritization tectonic activity. Conversely, the South pit exhibits higher initial Sc content in the protolith (~13 ppm) but lower average Sc content (~6.4 ppm) in the limonite zone, likely due to post-lateritization dissolution of Sc-hosting minerals by alteration and secondary weathering processes within the highly deformed pit. The findings suggest that while the Çaldağ deposit exhibits Sc concentrations up to ~66 ppm in the limonite zones, the potential for Sc as a by-product alongside Ni production is limited. Further detailed mineralogical and geochemical investigations are recommended to gain a deeper understanding of the mechanisms of Sc distribution in the Çaldağ deposit and other lateritic deposits in Türkiye.