Application of a batch hindered-settling model to dense-medium separations

Dense-medium separations were analyzed using a batch hindered-settling model. This model can predict the size/density distribution of settling particles at any point along a column. The separations were analyzed by treating the particles above a cut height as the product and the particles below this height as the refuse. This allowed fractional recovery curves to be generated for a wide range of simulation conditions. For this study, the variables examined included the size/density distribution of the coal, the solids concentration of the feed stream, the retention time of the particles, the cut height, the magnitude of the g force, and the size distribution of the magnetite. It was found that the separations were affected by the density gradient of the magnetite along the column, and as such, the results were often much different than those predicted by a batch free-settling model. The results from this study are presented in this paper.