The Hunter-Nash method uses a ternary phase diagram with phase separation and material balances to determine the number of equilibrium stages needed for liquid-liquid extraction (LLE). The system contains a solvent, a carrier, and a solute. A feed composition is selected from the drop-down menu. The solvent mass flow rate is given, and the desired raffinate (refined product) composition R_N is given. When “plot points” is selected, the “feed” (F), “solvent” (S), or “raffinate” (R_N) can be selected in order to display the corresponding point on the phase diagram. Selecting “mixing point” demonstrates how the lever rule is used to determine the mixing point M, and check the “show E₁” box to show how the extract composition from the first stage is found. Next, select “operating point” to show how the operating point P is determined. This also displays a schematic of the flow system. Finally, select “count stages” and move the “draw tie lines” slider to the right to show how to determine the number of stages and the raffinate composition leaving each stage. For any of the displays, check “show grid” to display grid lines on the ternary diagram.