Yes, although I hadn't thought about the sulfates.
True, he didn't state that, but if that's not what he means then what's he making a fuss about? If these particles are in fact an expected result of such a fire, to me the next question is "Okay, what's their most likely origin?" Perhaps that question has been addressed in combustion studies. If not, perhaps an expert like Thomas Eagar could provide informed speculation. Whatever the case, it seems logical to me to seek the counsel of people to whom the presence of the particles is not surprising, before looking for more esoteric explanations.
Prof, Thomas Eagar I believe, believes the particles would be the product of burning aluminum in the fires of a large Chimney effect. Which NIST discounts.
Aluminum I have found can burn, red, yellow, and white not just white hot, the oxide can form micro cracks letting oxygen into the material though the oxide layer.
However if the aluminum does not reach the point where the metal super heats the oxide becomes to thick to be broken easily.
In small particles like thermites heating and shock waves cause the compromise of the oxide layer that can not thicken to prevent an electro chemical reaction.
I have actually with sound not ultra sound Caused thermite sparks to jump from aluminum to black iron oxide, it seems to be an electromagnetic reaction.
They always jump from the Aluminum to the iron oxide never the other way around.
If you asked me for a probable theory the only thing I can think of is a sulfate reaction over time with the concrete and steel, made worse by rusting do to chlorine,
that would literally create the stage for either an Iron oxide reaction,with aluminum to super heat carbon and steel causing off gassing.
Or simply a carbon-Iron oxide, reaction, Similar to what I have done with carbon black from diesel to refine iron ore from natural stone on the farm into crude iron, it also produced similar effects.
The Aluminum Oxidizing reaction would require hot iron oxide falling into Aluminum. The carbon-Iron oxide reaction would require a chimney effect, also if you get a sufficient chimney effect you could possibly get ignited iron.
I have seen these effects myself, and I have night mares when I realize what the people in the buildings might have went though in them.
The real horror though is that if something like this can occur then others might be at risk that is why I keep searching, keep trying to figure it out!
This could possibly save untold lives if it were discovered we might learn how to prevent it because nothing says these events can not happen in standard fires.
To tell you the truth I am stumped, but still trying!