Group C particles have gradually become more desirable in the industry in recent years because of their special characteristics such as large specific surface area and small size. However, their poor flowability is the biggest challenge in applications. Nanoparticles, as flow additives, could significantly improve flowability of Group C particles. In this project, powder flowability was measured using three different techniques: FT4 test (cohesion), Avalanche angle (AVA) and Angle of repose (AOR). After nanoparticle modification, Group C particles present much smaller values of cohesion, AVA and AOR, indicating better flowability. In addition, fluidization behaviors such as pressure drop and minimum fluidization velocity were investigated. After nanoparticle modification, Group C particles exhibit good fluidization similar to Group A particles, thus achieving full fluidization with small minimum fluidization velocity. (C) 2019 Elsevier B.V. All rights reserved.