Synthesis and characterization of CaTiO3 powder by combustion synthesis process

Synroc is considered as a one of the most promising candidate for HLW solidification. CaTiO3, perovskite, which is a component of Synroc, can immobilize lanthanide and actinides by forming solid solutions. Generally most of the radioactive wastes elements were treated as a nitrate form. Therefore, the combustion process using metal nitrates as reactant materials can be easily applied to immobilize the radioactive waste elements. In this study, the feasibility of preparing fine, single-phase powders of multi-component oxide by a combustion process was investigated. Generally, the powder synthesized by combustion process showed different characteristics depending on the type and amount of fuel. And the spherical CaTiO3 particles were directly prepared from the aqueous solution by an ultrasonic mist combustion process using an ultrasonic nebulizers as mist generators. The particles prepared with simple spray pyrolysis method using nitrate solution without fuel as precursor solution showed porous and hollow morphology, while the particles prepared with precursor solutions containing fuel showed dense solid morphology. Among various kinds of fuel tested, glycine showed the best result in reaction kinetics and crystalline phase purity