The Hydrothermal Geochemistry of Tantalum

Tantalum (Ta) is recognized as one of the so-called ‘critical minerals’, with wide applications in the electronics and green energy industry but limited supply chain. An understanding of the speciation and solubility of Ta in hydrothermal solutions is key in helping both Ta exploration and mineral processing. High-resolution X-ray absorption spectroscopy (XAS) can reveal fine features of the XANES spectra, thus help identifying important Ta aqueous complexes (with O, F and Cl) that are hard to identify using conventional XAS detection techniques. This study plans to measure the coordination structure and solubility of Ta in hydrothermal fluoride and chloride solutions at up to 500 °C and 800 bar to better understand the transport and deposition properties of Ta and its fractionation from its geochemical twin niobium (Nb) in hydrothermal systems.