Many attempts have been made during the last forty years to evaluate the performance of gravity separation equipment, that is, the effectiveness with which light and heavy particles are separated. The most comprehensive treatment of the subject was made at the 1st International Conference on Coal Preparation held in Paris (1950) by Cerchar.. The float and sink analysis of the product is presented on a Gaussian distribution curve, resulting in an easier visualization of the inherent difficulties of separation. The gives of the distribution curve are then plotted, giving a quantitative measure of the deviation from perfect separation as an error distance instead of an error area.
Heavy Media Separation (HMS) Performance Criteria
In the ideal HMS process, all material lower in density than the specific gravity of separation (S.G.S.) would be recovered as floats and all material of higher density would appear as sinks.
In order to evaluate the misplaced material, the washery products are tested at the density at which the washing unit is operated. The original type of plot is shown and was developed primarily for coal cleaning units. The curve for raw coal represents the cumulative percentages of sink material. The refuse curve is also plotted as