Fluidization of nanostructured powders, potentially providing extremely high gas-solids contact efficiency, has become of interest in a number of emerging applications. Usually, nanopowders are characterized by the existence of large agglomerates of nanoparticles (NPs), whose size and density determine the fluidizability of the powder. Moreover, because of contact and tribocharging mechanisms, insulating nanopowders may accumulate large amounts of electrostatic charge due to their high specific surface area, which can lead to potential hazards when they are handled in industry. The system studied in this work is a silica nanopowder fluidized in a polycarbonate vessel. We show results from a noninvasive visualization technique able to automatically track NP agglomerate trajectories in the fluidized bed excited by an externally applied alternating field. This technique enables us to measure NP agglomerate properties such as their size, charge, and density.