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Old 27th December 2007, 11:57 AM   #115
Join Date: Mar 2007
Posts: 1,425
More Greening/Jones E-mails


I guess you didn't spend too much time reading my last e-mail! You know the part where I said:

"Thus we see that MSW ash typically contains up to 21 % Si, 8 % Ca, 8 % Fe, 1 % K and 5 % Al. Spherical particles up to 60 microns in diameter have also been reported in MSW incinerator ash formed when this type of waste material is burned at ~ 1000 deg C".

I also provided a link to a site that includes micrographs of microspheres in MSW ash. Did you check the link out? I guess not!

And as for coal fired boilers, a little research will show you that iron-rich microspheres are a well documented component of coal fly ash even though pulverized coal combustion temperatures are less than 1400 deg C. So you must accept that iron-rich microspheres do not need temperatures of 1538 deg C or higher to form in a coal/wood/paper combustion environment. If you cannot accept this fact there is no point in continuing this "debate"

The formation of iron-rich microspheres below the m.p. of pure iron at ~ 1537 deg C is a complex process but is possible, indeed probable, in an environment containing HCl/Cl2 and SO2/SO3 in the presence of O2 and H2O. The WTC fires produced lots of HCl from the combustion of PVC and oxides of sulfur were present from sources such as lead acid batteries, residual fuel oil and gypsum. In such a chemical soup, iron is transported as volatile di or tri-chlorides. FeCl2 has a m.p. of 677 deg C and allows "active" corrosion to occur with iron wastage rates as high as 100 g/m^2 per hour. The iron chloride is relatively unstable and eventually decomposes but the iron does not wind up as a pure iron microsphere. At the very least it will be oxide coated, (probably with Fe3O4), and alloyed with other metals such as Al. Fly ash usually contains mullite, Al6Si2O13. Pure mullite has a high m.p., ~ 1828 deg C, but small additions of K2O and/or CaO lower the m.p to below 1200 deg C. These complex Al/Si/K/Ca/O phases readily combine with iron oxide at ~ 1000 deg C to form iron-rich calcium/potassium aluminosilicate microspheres on cooling. Steven, as long as your microspheres contain Si and/or K and Ca, they are NOT derived from thermite.

And on the topic of Si in commercial thermite, I was always under the impression that thermite is a mixture of finely divided iron oxide and aluminum with small amounts of accelerants/oxidizers based on K, Mn Sr or Ba compounds. You, on the other hand, claim this is NOT the case simply because you detected Si in your thermite combustion residues. Did you carry out your thermite tests in a sand pit? I ask this question not to be facetious; I simply wonder why anyone would add a silicon compound to thermite! Anyway, please provide a reference for your assertion that thermite usually contains Si - a manufacturer's analysis sheet would be helpful in this regard.....

One final comment:

May I recommend that you read two very interesting articles by Ken Kosanke et al.:

"Characterization of Pyrotechnic Reaction Residue Particles by SEM / EDS" in J. Forensic Sci. 48(3), 531 (2003)

"Pyrotechnic Reaction Residue Particle Analysis" in J. Forensic Sci. 51(2), 296 (2006).

These articles discuss the problem of identifying pyrotechnic reaction particles in the presence of soil or "dirt". On page 535 of the first article we read:

"Although a little too simplistic to make it a general rule, most common geologic particles will have silicon and calcium as the most prevalent X-ray peaks, whereas pyrotechnic material will generally have little, if any, of these elements present."

Then on page 299 of the second article we see two EDS spectra labelled as "Dirt" and "Dirt plus pyrotechnic reaction residues". The spectra are essentially identical with peaks, (in order of intensity), identified as: Si, Al, Fe, Ca, K, S.

We can debate this in the New Year, if you wish, but until you can show me that iron-rich microspheres COULD NOT be present in the WTC dust without "added" thermite, I think we won't have much to talk about!



----- Original Message -----
From: Steven Jones
To: greening
Sent: Wednesday, December 26, 2007 11:55 PM
Subject: Re: High temps needed to form iron-rich spheres, meaning of ratios


Your latest response ignores (again) my questions in (4.) below.

Further, you state: "Now this is indeed quite strange because Si is definitely NOT an ingredient of commercial thermite."

This statement is demonstrably incorrect, and indeed I demonstrated that Si is in fact a component of the sample of commercial thermite I tested -- both in the unreacted thermite sample (in with iron oxide chips) and in the spheres which formed from reacting the commercial thermite. This observation I made was and is important to the discussion. Experiments trump authoritative statements from you or anyone else.

I am leaning to suggest we take this discussion to a forum, such as PhysOrg, beginning January 2 (as I leave town tomorrow once more, and then will be with family for New Years' eve and day). This would also permit further posting of PPT slides, or EDS plots and SEM images, as I did some time ago on a forum of

Let's think about this... Jan. 3 would be as soon as I could reasonably begin such a public discussion.


PS -- Carroll -- you will have to flesh out your question about PAC's and ferric chlorides, put into context of the WTC destruction, so I can fathom what you are asking when you say "What about PAC's..." etc.

Steven J

On Dec 24, 2007 9:16 AM, Steven Jones wrote:

"Only the very lowest melting substances form spheres." -- quoting directly from the figure caption of the spectrum you sent. I agree with THAT comment. The caption also mentions "metal foil" as part of the incinerated material, and I suspect melted aluminum would be present. NOT melted iron! Which leads again to the question I posed to you yesterday, based on the first spectrum you sent, which you seem to have thus far neglected:

4. This coal (your reference) was burned at high temperatures -- the caption refers to "high stoker temperature." This is a significant difference from the WTC fires -- or -- Are you claiming such high temps occurred in the WTC fires? Hot enough to produce iron-rich spheres? (Iron melts at 1538 C)

With regard to the lack of oxygen peaks in the older EDX machine you showed, I understand the difficulty these machines had -- and accept your explanation that an older EDX system was used for these spectra. The version I am using was installed very recently and is state-of-the-art. I will ask the lab director how good the oxygen percentages are in this new system.

Meanwhile, this new system does provide percentages of Fe, Al, Oxygen, etc.
So I have to ask -- what is the meaning of the ratios you provided, e.g.,

"Al : Si : S : K : Ca : Ti : Fe = 8 : 10 : 2 : 1 : 4 : 1 : 5"

When you answer this, we can make more direct comparisons with the percentages provided by the new EDS system. (Take your time as I'm traveling to be with family for Christmas. Merry Christmas! btw, and I wish you a speedy recovery as a friend tells me you had surgery recently.)

Thanks for the conversation.


PS -- some time ago, we crushed a concrete sample obtained from the WTC rubble, used magnetic concentration, and looked for iron-rich spheres. There were NONE found.

On Dec 24, 2007 7:39 AM, greening wrote:

Here is the incinerator ash spectrum. You will note that the caption reads "partly burned paper, wood, plastic, etc...

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