Improving flow and fluidization quality of fine and ultrafine particles via nanoparticle modulation

Fine and ultrafine particles possess great potential for industrial applications ascribed from their huge specific surface area and ability to provide good gas–solid contact. However, these powders are inherently cohesive, making it challenging to achieve smooth flow and fluidization. This challenge can be well-resolved by nanoparticle modulation (nano-modulation), where a small amount of nanoparticles is uniformly mixed with the cohesive fine/ultrafine powders. Through nano-modulation, the fluidization system of cohesive powders exhibits distinguishable minimum fluidization velocity, enlarged bed expansion ratio (particularly the dense phase expansion), and scarcer, smaller, and slower moving bubbles, indicating improved flow and fluidization quality. The purpose of the current work is to systematically summarize the state-of-the-art progress in the fluidization and utilization of fine and ultrafine particles via the nanoparticle modulation method. Accordingly, a broader audience can be enlightened regarding this promising fine/ultrafine particle fluidization technology, so as to provoke their attention and encourage interdisciplinary integration and industry-academia collaborative research. [Figure not available: see fulltext.]