Phase formation at synthesis of murataite-crichtonite ceramics

Phase formation at synthesis of potential waste form for actinide immobilization was studied. Oxide mixture with composition (wt.%): 55 TiO₂, 10 MnO, 10 CaO, 5 Al₂O₃, 5 Fe₂O₃, 5 ZrO₂, and 10 Gd₂O₃ (trivalent actinide and neutron poison surrogate) was compacted under 200 MPa at room temperature and sintered for 1–6 h at temperatures from 1200 to 1350 °C. As follows from X-ray diffraction and electron microscopy studies, the ceramics obtained is composed of two structural varieties of murataite and crichtonite-type titanate. The results were compared to ceramic waste forms produced by melting and crystallization.