This simulation shows a ternary phase diagram with a phase envelope. This diagram represents the phase behavior for mixtures of three components that are only partially miscible over a range of compositions so that phase separations occurs.

Click and drag the black dot, which represents the composition of the phase of the mixture, within the triangle. Each corner of the triangle is a pure component. The mass fractions for a phase or phases are displayed in a table(s). Click the "phases" button to view the one and two-phase regions (phase envelope). In the "diagram" view, check "tie lines" to view tie lines in the two-phase region. The endpoints of each tie line correspond to the compositions of the two phases in equilibrium (α and ß phases). Check "alpha phase" and "beta phase" to view these compositions. Points along the orange phase boundary are in the α phase and points along the magenta boundary are in the ß phase. Ternary phase diagrams can also be drawn with mole fractions instead of mass fractions.

1. Ternary Phase diagram with Alternative Phase Envelope. www.youtube.com/watch?v=AKJt3l68kFY.
2. Using a Triangular (Ternary) Phase Diagram [Video]. www.youtube.com/watch?v=gGYHXhcKM5s.
3. Interpolating Tie Lines on a Ternary Diagram [Video]. www.youtube.com/watch?v=n7DPiuHllZE

This simulation was created in the Department of Chemical and Biological Engineering, at University of Colorado Boulder for LearnChemE.com by Megan Maguire and Rachael Baumann with additional contributions from Professor John L. Falconer and Nick Bongiardina and was converted to HTML5 by Patrick Doyle, with additional contributions by Neil Hendren. Address any questions or comments to learncheme@gmail.com. All of our simulations are open source, and are available on our LearnChemE Github repository.

If this simulation is too big for your screen, zoom out using  +  on Mac or  +  on Windows. To zoom in, use  +  on Mac or  +  on Windows.