Processing of industrial minerals by selective flocculation

摘要

Selective flocculation involves the selective aggregation of one mineral or a group of minerals from a mixture contained in a finely divided, dilute suspension by the addition of a polymeric flocculant. Successive stages of the process are shown in Figure 1. The resultant flocs may be separated from the dispersed phase by sedimentation, elutriation or even froth flotation (floc-flotation). Selectivity is usually based on differences in surface properties and this can be achieved in several ways: by using a non-selective dispersant and a flocculant which has some affinity for a particular mineral by using a selective dispersant in conjunction with a non-selective flocculant (chelating groups with a strong affinity towards a mineral surface can be incorporated into the dispersant for a specific system) by introducing chelating groups into the flocculant structure, so that it has a strong affinity for a particular mineral surface (this technique can be used with or without a selective dispersant) by adding a surfactant to modify the surface of particular minerals, thereby altering its affinity for a flocculant.