1. Cantonear1968

    Cantonear1968 New Member

    A question for people more educated than I: does Thermate lower the melting temperature of iron?

    The full quote that I am dealing with:

    "Sulfur generates a eutectic system when molten thermate interacts with iron or steel lowering the melting point of iron. Wikipedia"

    Looking up the wikipedia page on thermate here.... https://en.wikipedia.org/wiki/Thermate ...I do not find that sentence. And I have searched but found nothing to corroborate his statement. My belief is that he is confusing "ignition temperature" with "melting temperature". Or does not understand the difference between "melting temperature" and "intergranular melting".

    This is of course in connection with the FEMA Appendix C paper. I'm waiting for clarification from the poster but thought I would post the question here.
  2. deirdre

    deirdre Moderator Staff Member

    it might be in reference to this?
    from "journalof911studies.com"
    this book lists the reference paper as
    and here is a thread (I haven't read) that seems to be discussing Sisson/sulpher https://www.metabunk.org/sulfur-at-wtc7-how-could-it-come-from-gypsum-as-the-bbc-claimed.t3383/
  3. Cantonear1968

    Cantonear1968 New Member

    Thank you for the response and I'd like to focus on the sentence I bolded. I may be splitting a hair that I don't truly understand, but as I read that it means it achieved a "liquid form" from a corrosive attack instead of heating. Yes, at at or around 1000C. But does that mean the "melting temperature of iron is lowered"?

    The poster is attempting to say that introducing sulphur to a thermate reaction means iron will actually "melt" at 1000C or there abouts. I see this as different while acknowledging it may all be above my head.
  4. deirdre

    deirdre Moderator Staff Member

    you'll have to wait for one of the science guys for your answer. But just keep in mind (as far as your conversation partner) the steel in WTC didn't melt.
    • Agree Agree x 1
  5. Oystein

    Oystein Active Member

    Disclosure: I am not very much a "science" guy - no background in metallurgy or anything of that kind. However, I have looked into the issue of the FEMA Appx C "intergranular eutectic melting" stuff enough to give a confident answer:

    Generally, mixing a metal with something else (alloying...) lowers the melting point.
    Think "melt iron, throw in sulfides or oxides or other metals, stir, let cool to solidify": That new material will have a lower melting point than pure iron.

    Nit-pick: Not any mix will have a single, well-defined melting temperature: Most of the time, one component will melt (have its crystal lattice dissolved) before the other(s) do(es), which tends to make the material "plastic", like wax. There are certain percentages of material mixes, called "eutectics" or "eutectic systems", where both/all components of the mix melt at the same temperature.

    Anyway, melting-mixing-stirring is only one way of creating an allow. On a microscopic level, when two materials get in contact, they will diffuse into one another and thus mix superficially. The surface then has a lower melting point.

    As for the steels analysed in that Appendix C, more specifically sulphur-rich species diffused in between the grains of the steel structure - which isn't smooth, it's granular. The process there was:
    1. Sulphur (actually: sulphides, sulphites, sulphates or sulphur oxide) diffuse into the intergranular area while hot,
    2. lowers the melting temperature on the grain's surface,
    3. surface melts,
    4. grain falls off,
    5. a fresh bit of surface thus gets exposed to the sulphur-rich gases
    6. repeat
    This is a relatively SLOW process. Biederman et al were not sure whether it took hours or weeks for those steel specimens to lose half an inch or so of thickness. We are, however, definitely NOT talking about seconds here!

    Cut back to thermate: It is actually not clear why adding sulphur improves the welding and cutting properties of thermite. It's most probably got more to do with the chemistry of burning sulphur and not with the forming of eutectics in the intergranular cavities.
    • Agree Agree x 1
    • Informative Informative x 1
  6. Cantonear1968

    Cantonear1968 New Member

    Thank you Oystein. As much as I expected, the poster came back and stated he uncritically repeated it from a YouTube video. No corroborating evidence.

    I appreciate your response on this.