Tailings flocculation and settling in a lab‐scale thickener by multiscale CFD modeling approach

Flocculation‐thickening is an important solid–liquid separation operation in chemical engineering. The flocculation in the thickener feedwell plays a key role in the tailings slurry thickening process. This study develops a sequential multiscale model for a lab‐scale deep cone thickener to examine the effects of feed solids concentration on flocculation and settling. A computational fluid dynamics–population balance model describes aggregation and breakage in the feedwell, and its predicted floc‐size distribution informs a two‐fluid kinetic theory of granular flow settling model. Intermediate concentrations promote aggregation through favorable turbulence dissipation and particle collisions. At higher concentrations, increased slurry viscosity and particle hindrance suppress large‐floc settling. These findings link local particle interactions to process‐scale separation performance and support thickener design and operation.