Interactive Self-Study Module: Ternary Phase Diagrams
Department of Chemical and Biological Engineering, University of Colorado Boulder 

This module uses screencasts and interactive simulations to explain how to use ternary phase diagrams. It then provides example problems and step-by-step quiz simulations to allow the user to test themselves. We suggest using the learning resources in the following order:

  1. Attempt to answer the multiple-choice ConcepTest and solve the example problem before watching the screencasts or working with the simulations.
  2. Watch the screencasts that describe the phase diagrams and answer the questions within the screencasts (when available).
  3. Use the three interactive simulations to further understand the behavior of the phase diagrams.
  4. Use the quiz interactive simulation to test your understanding by carrying out step-by-step preparation of ternary phase diagrams.
  5. Try to solve the two example problems before watching the solutions in the screencasts.
  6. Answer the ConcepTests.

Ternary phase diagrams are important for liquid-liquid extraction and are used in the Hunter-Nash method to determine the number of stages required for separations. 

This module is intended for material and energy balances, thermodynamics, and separations courses. 

Before studying this module, you should:

After studying this module, you should be able to:
  1. Given mole fractions of each component, locate that composition on a ternary phase diagram. 
  2. Given phase equilibrium data for a ternary system, locate the phase envelope on the phase diagram and draw tie lines.
  3. For a mixture composition in the two-phase region on a ternary diagram, use the lever rule (or a mass balance) to determine the amount of each phase.