| Abstract Scope |
To support Australia's green energy transition, initiatives like the Australian Critical Minerals Prospectus, New South Wales’ (NSW) Critical REEs program and Queensland (QLD) New Economy Minerals Initiative were launched to secure sustainable supplies of critical minerals. In alignment, slag materials from five QLD and NSW mine sites were sampled between 2020 – 2023 as part of the initiatives. These sites represent diverse ore systems, primarily copper and/or gold, with heterogenous slag textures. Geochemical analysis revealed elevated concentrations of critical (e.g., In, Bi, W) and precious metals (e.g., Cu, Ag, Au). Mineralogical characterization using XRD, MLA and SEM-EDS showed dominance of Ca-Fe silicate, olivine, pyroxene and glass phases. Notably, NSW slag’s olivine was enriched in Bi (up to 9,574 ppm) and Pb (43,920 ppm), while QLD’s slag contained Au (up to 5.04 g/t). These results indicate critical metal signatures, inform extraction strategies, and can support future economic rehabilitation opportunities. |