Hi Chris7,
You asked for proof that aluminum could be discolored by other things in the WTC fires and not be bright silvery. This aluminum soup recipe will resolve the question once and for all:
Melt one ton of aluminum in a strong steel container and bring to 1400 degrees F.
Add:
five padded office chairs
50,000 sheets of paper from filing cabinets
seven airplane seats
Lube oil of all kinds
12 computers circa 2000 with screens and all associated hardware
Six curtains
Five office dividers
The contents of seven randomly selected pieces of airplane luggage
Articles of clothing, hardware supplies, kitchen utensils, etc.
Fifty pounds of colored plastic items available in a typical office
For spice, Mix in melted Bronze, Brass, Magnesium and Zinc to taste.
To stir it up, add the following items which create explosions in building fires: HVAC equipment including condensors and compressors, Cleaning supplies, CRT type TV's and computer monitors, Large motors that have an oil reservoir for lube (Elevator lift motors), hydraulic pistons found in office chairs, and UPS battery backups.
Cook for 80 minutes, then pour half of it it out the opening of a burning building for all to see. Pour the rest of the aluminum soup into a debris pile and dump water on it. You'll probably get lots of violent steam action but if you're careful like the 911 firefighters were you should be OK.
Finally, melt the steel pot that was holding the soup and bring it up to 2800 degrees F. Pour the molten steel into a pile of debris and pour water all over it like the firefighters did on 911. Stand back; it will NOT behave in the same way!! In fact, it might kill you.
Special Cooking Contest: If you follow this recipe to the letter and my aluminum soup is a pure bright silvery color, I will send you a check for $91.1 (I've upped the ante by a factor of ten from my original contest offer)!