Industrial use of single parameters as a tool to improve separation selectivity

This paper presents the results of theoretical and experimental studies to establish the separation selectivity under the effects of one or more separation features in various types of devices, such as jigging machines, dense-medium separators, and hydrocyclones. When processing minerals, the separation of mineral components into concentrate(s) and tails is often carried out based on several features simultaneously, which leads to lower processing efficiency. Obviously, it is easier to separate discrete raw materials using a single parameter, rather than based on several features at the same time. The significance of separation characteristics may be quantitatively assessed, for example, using the contrast ratio of raw materials. In order to improve the selectivity of separation processes and the sensitivity of separation devices, the separation by grain sizes and density must be performed in series in several stages, while using narrow machine classes. In gravity concentration processes, for example, with the use of hydrocyclones, the first stage involves separation by size, and the second stage separates the underflow by density using screw separators, concentration tables, jigging machines, densemedium hydrocyclones, or gravity concentrators. When selecting a gravity concentration device, not only its effectiveness, but also its capacity shall be taken into account. Screw separators and concentration tables have low overall capacity and, therefore, in the conditions of large-tonnage sections of existing processing plants, jigging machines and dense-medium plants and/or gravity concentrators shall be preferred.