Cerium oxide is widely used in fine polishing processes, such as the production of optical lenses, prisms, LCD panels and HDD glass substrates. More than 90% of rare earth elements used in Japan, including cerium, have been imported from China, and their prices have risen sharply. Therefore, reuse and/or recycling are urgently required. Our previous study of technologies for recovery of cerium-oxide abrasive particulates from used slurry revealed that freezing and thawing caused particulates to agglomerate and form aggregates that can be easily separated by sedimentation. In this study, we examined the mechanism of secondary particle formation and found that secondary particle formation might be aided by glass components in used slurry. We next examined the behavior of sodium silicate and colloidal silica as models of the glass components in slurry and found that they were agglutinated by freezing and thawing. It was observed that glass components adhered to the abrasive particle surfaces in used slurry. The glass components on the abrasive particle surfaces probably aid the adhesion of abrasive particles during freezing and thawing.