Syntheses and spectroscopic characterization of uranium(VI) silicate minerals

In this study, the secondary uranium(VI) silicate minerals boltwoodite, sodium boltwoodite and uranophane were synthesized. Sodium boltwoodite was successfully obtained following a new reaction procedure. Their analytical characterization was carried out by means of inductively coupled plasma mass spectrometry and atomic absorption spectroscopy, scanning electron microscopy, X-ray powder diffraction, differential thermal analysis combined with thermogravimetry and infrared spectroscopy. Furthermore, the fluorescence behaviour was measured using time-resolved laser fluorescence spectroscopy. Herewith, the fluorescence properties of the three silicious uranyl phases were determined at room temperature.