Synthesis of Potassium and Calcium Uranovanadates, analogues of Carnotite and Metatyuyamunite Minerals

Abstract

The aim of this study was to develop a synthesis of metatyuyamunite (Ca(VUO$_{6})_{2}\cdot$3-5H$_{2}$O) and carnotite (KVUO$_{6}\cdot$1-3H$_{2}$O) under hydrothermal conditions. Also, crystals obtained from this synthesis were compared with crystals from melting method. The analyses of synthesis products were performed by X-Ray techniques. X-Ray Diffraction was used for both species identification, whereas Scanning Electron Microscopy was used to analyze their morphology and elemental composition. Both uranovanadates were positive synthesized under hydrothermal conditions; besides, their morphology presents particles agglomerates. Calcium uranovanadate agglomerates contain well-defined crystals, whereas potassium uranovanadate agglomerates consist in fine powder particles.