Uranium solubility and speciation in reductive soda-lime aluminosilicate glass melts

• Uranium solubility has been determined in soda-lime aluminosilicate glasses HR-XANES can be used to determine uranium oxidation states glass melt decreases the order U VI > V IV The hexavalent content is a key factor for melts of Na 2 O-CaO-Al O 3 -SiO system with two different Na/Ca ratios was studied at temperatures 1250–1400°C and under various redox conditions. A closed thermochemical reactor control alkali metal activity (sodium oxide content) oxygen fugacity imposing reducing environment on (10 −5 atm < fO 10 −15 atm). compositions quenched were analyzed by scanning electron microscopy probe microanalysis. It appeared that decreased decreasing fugacity, elucidating roles valences uranium. To account respective effects theses valences, we proposed method proportion each state sample. coexisting , species have characterized first time samples using M 4 edge high energy resolution X-ray absorption near-edge structure. Results showed lowest values, approximately 1 mol% UO obtained strongly conditions, thus as main valence. Under higher controlled drastically enhanced concentration melt.