Ice slurries of nanosilica fluid at different concentrations were prepared by dispersing silica nanoparticles in aqueous solutions of either ethylene glycol or sodium chloride. Images of ice crystal particles in ice slurries were obtained by a microscopic observation system. The resulting size distributions of ice crystals were compared to normal

log-normal

Gamma

and Weibull distributions so as to investigate nanosilica effect on average diameter and size distribution of ice particles and to study dimensional change of ice particles during storage of ice slurries. The experimental results indicated that ice particle sizes were fitted well with Gamma distribution before and after addition of nanosilica. Nanosilica played an important role in grain refinement such that sizes of ice particles decreased linearly with increasing concentrations of nanosilica. When ethylene glycol aqueous solution was base fluid

nanosilica addition effectively inhibited growth of ice particles during slurry storage. When sodium chloride aqueous solution was base fluid

concentration of nanosilica had to be increased from 0.25% to 0.75% for similar inhibition effect. Therefore

nanosilica could be used to reduce particle size and to control growth of ice crystals

which has an important application for flow and heat transfer improvement of ice slurry.