Dynamic Modeling of Yield and Particle Size Distribution in Continuous Bayer Precipitation

Organic compounds in the processing of lateritic bauxites to alumina Part 2: Effects of organics in the Bayer process

“…This process accelerates the rate of crystallization by secondary nucleation at the gibbsite surface and the consequent production of new growth sites. At still higher supersaturation, macroscopic seed particles may also grow by agglomeration (Ilievski and White, 1995;Stephenson and Kapraun, 1997). All of these processes are present in modern Bayer precipitation circuits (Tschamper, 1987).…”

Dynamic response of a plant-scale gibbsite precipitation circuit

“…The energy balance for the precipitation tanks accounts for a convective heat exchange with the environment under ambient conditions. Classification in the hydrocyclones and thickener is modelled using a recovery curve concept as described by Stephenson & Kapraun (2013). Ideal separation curve was assumed for the hydrocyclone separation, which means no carry-over of fines to the underflow.…”

“…It predicts a dynamic response over the full particle size distribution (PSD), which is crucial for evaluating the overall precipitation yield and product properties. Different to the gibbsite precipitation models published previously, such as ASPEN (Stephenson and Kapraun, 2013), SysCAD (Stamatiou et al, 2013), and Matlab/Simulink (Zhang et al, 2011) models, our precipitation circuit model predicts a dynamic response of the full particle size distribution with accuracy matching the experimental 300 channels M A N U S C R I P T…”