Molybdenum speciation in aqueous solutions and porphyry ore deposits

Porphyry ore deposits are the primary source of molybdenum and copper currently used. Our knowledge of the molybdenum solubility and its molecular species in aqueous fluids under hydrothermal conditions is key for understanding the formation of these deposits. We use X-ray Absorption Spectroscopy (XAS) with synchrotron radiation to study solutions at high temperatures and pressures typical for the Earth’s crust. The results will enable a first quantitative assessment of the role of the radical sulfur ion S3•- and other dissolved components in molybdenum transport by hydrothermal fluids and will allow to improve the thermodynamic models of this transport at high temperature and pressure in natural systems.