Effect of particle shape on particle-bubble attachment behavior by numerical simulation: CFD-DEM

Based on the particle–bubble interaction mechanical model, this study developed a three-dimensional (3D) discrete element method (DEM) simulation model using the secondary development capabilities of EDEM software combined with CUDA-API. The attachment stability between particles and bubbles in flotation is crucial for improving the recovery efficiency of fine mineral particles, yet the effect of particle shape remains unclear. Therefore, a coupled CFD-DEM numerical simulation framework was employed to investigate particle–bubble attachment behavior. Five types of irregular particles and three types of regular particles were designed, and simulations were conducted considering varying particle densities (1500, 2000, and 2500 kg/m³) and volumes (0.5, 1.0, and 2.0 × 10-³ mm³). The results show that irregular particles exhibit greater velocity and sliding fluctuations than regular ones during attachment. As particle density and volume increase, the attachment stability between particles and bubbles gradually decreases, making detachment more likely at lower flow velocities and thereby reducing the critical detachment flow velocity. Irregular particles with lower sphericity show further reduced attachment stability due to their complex geometries. For example, the critical detachment velocity of irregular particle a is approximately 46%, 40%, and 39% lower than that of the regular octahedral, cubic, and dodecahedral particles, respectively.