A ternary mixture is a three-part mixture of some substance. Ternary mixtures are especially important in fluoride reactors because there are some three-part mixtures that have very attractive properties. A three-part mixture of lithium, beryllium, and uranium fluorides can be used as a fuel in a fluoride reactor.
The lithium and beryllium fluorides are mixed together to make an attractive “solvent” for the uranium fluoride…much like the water in salt water. Uranium tetrafluoride, all by itself, has a melting point of 1035 degrees Celsius. Lithium fluoride all by itself has a melting temperature of 848 degrees Celsius. But when you mix LiF, BeF2, and UF4 together in the right proportions you can get that melting temperature down as low as 350-400 degrees Celsius.
A lot of work was done at Oak Ridge and other laboratories in the 1950s and the 1960s to understand these ternary mixtures and their properties. One of the most important things to understand was how melting temperature changed with the composition of the mixture. So they developed experiments and they plotted their results on ternary mixture diagrams, like this:
Now I’ll confess–I’ve been looking at these diagrams for years and really haven’t been able to understand them. All I could see was a triangle where each vertex (point) is labeled with the name of one of the components of the mixture. There’s a bunch of contour lines in the middle that I knew represented lines of constant melting temperature, but I could no more use the diagram than fly to the Moon.
So, I did what any good curious engineer does when he needs to learn something quick–Google search! And sure enough, it wasn’t long before I found a couple of nice sites that taught me how to read a ternary mixture diagram:
These sites were helpful and useful, but after plotting out a ternary diagram on the printer and breaking out the pencil and ruler and trying to figure out which way the lines should go, I was a bit frazzled. So I thought there should be an easier way, since I was pretty sure most folks wouldn’t be interested enough in ternary diagrams to go to all this trouble.
So I combined my interest in ternary diagrams with my enjoyment of Java programming to build an interactive tool that would allow folks to mess around with different ternary mixtures and see how their properties change as they chose different combinations.
There’s still a number of features that I want to add, but for now, you can run this simulation and move your mouse cursor around inside the triangle, and the simulation will figure out what composition of the three materials corresponds to the location of your mouse. The best part is that it will figure this out for you automatically without having to use pencil and ruler like I did!
Ternary Mixture Simulation (Java WebStart)
If you like it, let me know. If you hate it, be gentle. If you want some new feature, leave a comment and I’ll see what I can do.