I think you should add some of the measures temperatures of the pile and some of the temperatures measured in a furnace. Since the pile was a big furnace
Well, it was a big
pile, with some fires burning in it, and some areas that might have acted like furnaces when the air went through them right at some time.
I think there's a danger is seeking explanations for things like "molten steel" or "high" temperatures, when there's no real evidence that those things existed. There's absolutely zero physical evidence of "large pools of molten steel"
What were the temperatures measured in the pile, and how were they measured? Were they measuring the temperature of solid matter in the pile or the temperature of flames/gas?
NIST discusses various temperature points:
https://www.nist.gov/topics/disaster-failure-studies/faqs-nist-wtc-towers-investigation
And discuss molten steel in the pile without reference to temperatures:
The AVRIS data from Sept 16 is loosely described as "over 800°F", and the highest temperature mentioned is "727°C/1341°F" for "14% of the pixel" in hot spot A" (which is actually not as precise as it sounds, being a rough fit to a round figure of 1000°K)
https://pubs.usgs.gov/of/2001/ofr-01-0429/thermal.r09.html[Broken External Image]:
https://pubs.usgs.gov/of/2001/ofr-01-0429/hotspot.key.tgif.gif
Actually, hotspot G is listed at 1020°K, 747°C, 1376°F, but basically the same given the accuracy range.
And this was not "in the pile", it was the surface of the pile visible from above. Does that mean the interior of the pile was a lot hotter 747°C in places - yes it does, but remember that a hydrocarbon fire can burn at 800°C to 1100°C, so having some visible spots at 727°C is entirely in keeping with a normal non-furnace hydrocarbon fire (i.e. wood, paper, and plastic). Thre
And these two spots (A and G) were the HOTTEST of the hot spots. Other hot spots were in the range 700 to 900 Kelvin, which is 427°C/800°F to 627°C/1160°F. All far off the 1100°C/2012°F of a hydrocarbon fire.
Now furnaces that melt iron will have to get that iron to the much hotter 1538°C/2800°F. Usually, this is done with forced air in an enclosed space, which would be termed a "forced air" furnace. But it can also be done in a "draft" or "natural draft" furnace where the air flow comes from the convective action of the fire rising through a chimney and creating a draft. There are a few videos of such furnaces, but blast furnaces are more common.
Even with the blast furnaces though, "molten steel" is not really something they make. What these simple furnaces produce (through careful feeding, use of charcoal, and maintaining the air supply) is a "bloom" of iron and slag that has a combined lower melting point than pure iron.
If there was an accidental furnace in the pile, it's unlikely it would have got hotter than a deliberately designed draft furnace.
Here's some data for a variety of forced-air furnaces:
https://www.saimm.co.za/Journal/v084n09p285.pdf
Again though, the "temperature" of a fire is a complex thing, and you need to be clear what you are actually measuring.