Solvent Extraction 355 8. Ease of recovery-as transfer of the solute from the feed still entails the further separation of solute from the solvent, solvent recovery will need to be as complete and pure as possible to permit recycle to the extractor as well as minimizing losses and potential pollution problems 4.0 CALCULATION PROCEDURES Sizing the equipment required for a given separation will depend both the flow rates involved and the number of stages that will be required with a binary equilibrium plot, Fig. 7, the distribution of extract and raffinate following one stage of contact is readily determined. Representing a mass balance of the solute transferred (Ys -YE S=(XF-XRF ( (X x Thus, a line can be drawn from XF, with a slope of F/s to the intersection with the equilibrium line, thus establishing YE and XR Figure 7. Graphical solution for single contactSolvent Exiraction 355 8. Ease ofrecovepas transfer of the solute from the feed still entails the further separation of solute from the solvent, solvent recovery will need to be as complete and pure as possible to permit recycle to the extractor as well as minimizing losses and potential pollution problems. 4.0 CALCULATION PROCEDURES Sizing the equipment required for a given separation will depend upon both the flow rates involved and the number of stages that will be required. With a binary equilibrium plot, Fig. 7, the distribution of extract and raffinate following one stage of contact is readily determined. Representing a mass balance of the solute transferred: Thus, a line can be drawn from X,, with a slope of F/S to the intersection with the equilibrium line, thus establishing YE and X,. Y X Figure 7. Graphical solution for single contact