Hi Jerry. If you are interested in thermite, you may wish to read:
http://journalof911studies.com/volum...emistryWTC.pdf
Especially interesting is Figure 3. Disregard all the non-thermodynamic stuff. The appendix is a great reference section for the temperature dependent heat capacities of the reactants. The iron phase transitions are neglected, and these will cause the calculations to be optimistic (pessimistic
). But the error introduced by neglecting radiation and other mechanisms of heat loss is much higher.
I wonder that, with sufficient diluent in the form of low carbon steel/iron, you could decrease the temperature requirement of the refractory. The characteristic heat transfer time for small steel punchings or granules is probably on the order of a second, with the high radiative component.