Calcined resin microsphere pelletization (CRMP): A novel process for sintered metallic oxide pellets

This study deals with the preliminary development of a powder-free process called calcined resin microsphere pelletization (CRMP) used for the fabrication of metallic oxide pellets. This dustless process could be used for the fabrication of mixed U1−yAmyO2±x pellets dedicated to the transmutation of Am in fast neutron reactors. In this study, porous CeO2 microspheres, used as a surrogate of AmO2, were obtained after mineralization of cerium loaded ion exchange resin beads. These millimetric oxide microspheres were die-pressed into pellets which were then sintered under air to form ceramic pellets. Their densities approached 95% of theoretical density of CeO2 and a homogeneous microstructure was obtained by using optimized microspheres. The influence of calcination parameters on the characteristics of microspheres and on the properties of sintered pellets is discussed.