TY - JOUR A1 - Noubactep, C. A1 - Sonnefeld, J. A1 - Merten, D. A1 - Heinrichs, T. A1 - Sauter, M. T1 - Effects of the Presence of Pyrite and Carbonate Minerals on the Kinetics of the Uranium Release from a Natural Rock Y1 - 2006 VL - 270 IS - 270 SP - 325 EP - 333 JF - Journal of Radioanalytical and Nuclear Chemistry DO - 10.1007/s10967-006-0352-x DO - 10.23689/fidgeo-2484 N2 - The influence of calcite, dolomite, pyrite and vaterite on the kinetics of uranium (U) release from a natural rock under relevant i.e. field conditions has been investigated. The time dependence of the U release has been studied in two different experimental procedures (open and closed systems) at laboratory temperature (21 ± 2 °C). Performing batch experiments in tap water, the U release efficiency of a natural U-bearing rock was characterised in the presence of varying amounts of three different carbonate bearing minerals for experimental durations of up to 782 days. Another experiment was conducted for a period of 14 days in the presence of a pyrite mineral. The results demonstrate that the presence of carbonate minerals does not have any significant influence on U release in closed systems where the U concentration at saturation was ca. 54 mg/L. In contrast, in open systems, the U concentration was ca. 8 mg/L at saturation and the effects of all additives both on kinetics and saturation concentration of U were apparent. UR - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/6797 ER -