Structure And Properties Investigation Of Barium Iron Phosphate Glass

Barium effectively improves the thermal stability and chemical durability of iron phosphate. Moreover, it can increase solubility for sulfate of high-level radioactive waste in iron phosphate glass, increase capacity of some radionuclides waste. It became a potential vitrification base material. In the paper, 40 Fe2O3–60 P2O5(mol%) glass is regarded as matrix materials. And BaCO3 and BaSO4 are regarded as barium source, respectively. The physical properties, microstructure and chemical durability of xBaO–(100-x)(40 Fe2O3–60 P2O5) glass have been studied. The occurrence form of sulfur have been also studied in x BaO–(100-x)(40 Fe2O3–60 P2O5) glass.The results suggest that the solubility of barium in these iron phosphate melts is less than 30 mol% BaCO3. In the glass-forming range, the structure of barium iron phosphate glasses which were made up of predominantly pyrophosphate groups(Q1) with a small proportion of metaphosphate(Q2) and orthophosphate groups(Q0). Q1 structural unit decrease and the structural unit Q2 increase with the content of BaO increases. The density, hardness and the glass transition temperature of the glass samples increases with increasing barium oxide content. These changes indicate that barium oxide improve the mechanical properties of the glass, the network structure of glass become more densification. Meanwhile Ba2+ to join, thermal stability and chemical durability of the glass has been effectively improved.The solubility of barium in these iron phosphate melts is less than 20 mol% BaSO4 and the solubility of sulfur is the maximum 0.36 mol%. In the glass forming range, the density and hardness increase with addition barium sulfate. The structure of the studied glass is no obviously change. The addition appropriate amount barium sulfate can improve the stability of the glass, and there is high thermal stability and chemical durability comparison with barium sulfide-free iron phosphate glass. Therefore, the barium iron phosphate glasses vitrify the sulfide-containing high-level radioactive waste.