My simple question may be hard to answer tho: can anyone provide me with a photo of iron microspheres in fly ash, clinging to a recently-welded steel beam, or in printer toner? Or, in support of the competing RJ Lee hypothesis that the iron microspheres were created during the 911 fires, can anyone show me pictures of iron microspheres that are known to have been created in a standard building fire?
The image and accompanying spectrum come from my analysis of a selection of Tolk fly ash. As a side note, doing particle analyses of dust, ash and other particles is about 25% of my job, and I maintain a database of about 400,000 particles from fly ash samples alone. My analysis uses exactly the same method and instrument that RJ Lee uses, and I classified this particle as "Iron Rich". Obviously, this particle is an iron oxide of some type, but the particle clearly contains small amounts of calcium, silicon and aluminum.
A few points to make about fly ash:
- Fly ash is traditionally analyzed using X-ray Fluorescence (XRF). Most XRF instruments do not measure oxygen directly, but they make the simplyfing assumption that all inorganic compounds found in the samples are oxidized to their most common oxidation states. Thus, if iron is found, it is assumed to be stoichiometric Fe2O3.
- I cannot stress enough that most particles found in dust and ash are comprised of oxidized compounds. Silicon is identified as silica, aluminum is alumina, calcium is calcium oxide.
- X-ray methods, whether X-ray induced (XRF or µXRF) or electron induced (SEM-EDX or EPMA) are not sensitive to hydrogen, helium or lithium. It is very difficult to differentiate between FeO2 and Fe(OH)2 using X-ray fluorescence. Even though the iron is in a different valence state, the production of X-rays, especially K energy X-rays, is largely unaffected. Only composition matters in XRF.
Obviously, since we're dealing with iron oxides, iron hydroxides, and iron eutectics (which themselves may have extra hydrogen and oxygen), the assumption that "iron rich" spheres must come from fire temperatures capable of melting pure iron is preposterous.
Also, it's important to remember that fires don't need to efficiently create iron rich microspheres. Rather, they need only to
concentrate those iron rich microspheres in the dust. As these spheres presumably have a low amount of combustable material, it's reasonable to assume that they're going to survive a fire unchanged, whereas the parent material (paper, wood, carpet, organic paint binders, etc) will not survive in tact. Ash is not a random sampling of all the materials in a fire, it is a random sampling of materials that do not readily combust, of which iron bearing compounds are going to be a significant part.
Have you ever tried to cook a bag of fresh spinach? Get a bag that's 3 feet tall and dump it into an average frying pan with a bit of oil. In addition to making a delicious fried spinach, you'll also notice that you can fit the entire bag in that little pan. How? You got rid of all the material that can evaporate readily, and what's left has very little water left in it. A fire does the same things to a building. By volume, the amount of iron microspheres in paint may be 0.001%, but if the other 99.999% of the material is combustable, the iron microspheres will be all that is left over.
