Design of solvent extraction circuit schemes

The technology of solvent extraction in the hydrometallurgical industry typically consists of two circuits, an extraction circuit and a stripping circuit, coupled by a common solvent. Process flow patterns regularly range from single-solvent circulation loops to schemes employing solvent and aqueous bypass or intermediate solvent recycle. The design of these processes using graphical methods runs into a series of complications produced by the coupling of the flow loops. In this paper, a graphical method is developed for the preliminary analysis of different flow structures for these coupled circuits. The method is simple and can be performed by hand. Several examples are presented to illustrate the utility of the proposed method.