11:20 AM - 11:35 AM
[3F08] Development of solidification techniques with minimised water content for secondary radioactive aqueous wastes in Fukushima
(3)Effects of phosphates on calcium aluminate cement under hydrothermal conditions
Keywords:Phosphate cement, Calcium aluminate cement, Hydroxyapatite, Hydrothermal treatment, secondary radioactive aqueous wastes
The present study investigates the effect of phosphates on hydrothermal treatment of CAC system at 60ºC, 105ºC and 180ºC. The treatment of conventional CAC resulted in formation of stable C3AH6 and γ-AlOOH. Modification by mono-phosphate appeared to have delayed the hydration and overall reaction of CAC, whereas poly-phosphate appeared to significantly stabilise the amorphous binding phase up to 180oC. No crystalline phase was observed except hydroxyapatite when poly-phosphate was used.