The Titanosilicate Glass Matrix for Immobilization of the Wastes Containing felements
The compositions of titanosilicated glasses were defined in the ternary system Na2-OTiO2-SiO2, which provide not only a perfect glassylike structure (body) formation, but also associative groups of minerallike compoundsfresnoite (Ba2TiSi2O8) and perovskite (SrTiO3) were implemental as well. These associates can incorporate felements very firmly. To study how these associates can incorporate felements europium and uranium oxides were added to the system in amount of 3 wt.%. Transformation, which took place during the presynthesis of glasses and their crystallization, were investigated by Xray diffraction (XRD) and differentialthermo analysis (DTA). Distribution of Eu and U throughout the melts body in steady state conditions was detected using laser fluorescence method. As a result, Eu was uniformly distributed in the volume while U has a tendency has a tendency on sedimentation at bottom part due to gravitation. Oxidation state for Eu was (+3) and U was in (+6) state. Because glass networks were based minerallike associates, namely fresnoite and perovskite, chemical durability of produced glasses was very high level, since equilibrium leach rate of Eu was 3⋅10–6 g/m2⋅day and of U was 4⋅10–6 g/m2⋅day.