The Solubility of Some Alkali-Bearing Zr Minerals in Hydrothermal Solutions

Abstract

AbstractThe hydrolytic dissolution of some Zr-bearing minerals has been measured in aqueous KCl and KF solutions. Depending on the mineral being investigated, Zr concentrations varied from about 9 ppb to nearly 40 ppm in equilibrated solutions; this validates the notion of Zr mobility in some crustal fluids. At 50 °C, ΔfG were determined (using the measured solubility products) for Na catapleiite, elpidite, vlasovite and weloganite to be -4654.2±5.6, -7391.0±11.6, -5181.0±7.3 and -7130.5±1.0 kJ/mol, respectively. Calculated phase relationships amongst the zirconosilicates found at the Strange Lake peralkaline complex indicate that elpidite and gittinsite cannot coexist stably implying a two-stage hydrothermal mineralization process.