Flow Field Study of Sodium Aluminate Solution Slurry in an Unagitated Precipitation Tank by CFD Simulation

Abstract

In order to explore the feasibility of remove agitation in gibbsite precipitation process, computational fluid dynamics method was carried out to study the flow field of sodium aluminate solution slurry in an unagitated precipitation tank. The solid content distribution is investigated by volume fraction of solid phase. The simulation results showed that little difference of solid content is found in the range between the tank bottom and the height position of 25 meters, which is the most zone of the tank, and there is a somewhat large difference in the top 5 meters zone, where the stratification occurs. With the inlet velocity increases, the zone of stratification shrinks to near the tank surface, which makes the solid content distribution in the whole tank seem uniform much more. Therefore, without agitation, the solid content would not concentrate to tank bottom completely in the normal work flow.