1. Mick West

    Mick West Administrator Staff Member

    Some of the sparks seemed to follow a non-ballistic trajectory (i.e. they don't travel in straigtht line). So some force is acing on them after they fly away.

    HOWEVER, on examination of the video, the small sparks that did change direction are actually just bouncing off the glass.

    Metabunk 2018-02-23 08-06-15.
    The small sparks all do seem to go in straight lines, indicating one very short propulsion event.

    There are some larger sparks that seem to meander slightly, but it's hard to tell.

    Surely there must be some in-depth study of sparks somewhere.
  2. Mick West

    Mick West Administrator Staff Member

    Another way of making iron microspheres would be to shave off steel with a file, and then ignite it by passing it through a flame. This, I think, would be similar to the angle grinder method, but with a different source of combustion.

    I'd previously tried igniting the shaving from cutting with a reciprocating saw, but they were too big. After breakfast I shall go find my bastard file.
  3. Mick West

    Mick West Administrator Staff Member

    And, just for completeness, you could probably makes some iron microspheres by burning a bowl of cornflakes. Cereals are "fortified" with iron by actually adding some iron dust.
  4. Mick West

    Mick West Administrator Staff Member

    Metabunk 2018-02-23 09-18-40.

    Shaved off this corner, used strong slow strokes.
    Metabunk 2018-02-23 09-19-19.

    Metabunk 2018-02-23 09-20-22.

    Lighting it close up with a Bic was problematic, any combusted sparks seemingly got advected (carried by the air) away. Also the lighter stuck to the magnet.
    Metabunk 2018-02-23 09-17-01.

    So I ended up sprinkling them into a faster moving flame.
    Metabunk 2018-02-23 09-23-12.
    This probably meant I lost most of the spheres, but some remained.
    Metabunk 2018-02-23 09-24-28.

    Metabunk 2018-02-23 09-25-55.

    Before I burnt it I check for microspheres. I could find none. It looked like:
    Metabunk 2018-02-23 09-26-52.

    After burning it looked like:
    Metabunk 2018-02-23 09-27-31.

    Some color changes and the formation of "wired" microspheres.

    Scattered around were some sparked microspheres:
    Metabunk 2018-02-23 09-29-05.

    Metabunk 2018-02-23 09-29-33.
  5. Mick West

    Mick West Administrator Staff Member

    Three sheets of laser printed paper.
    Metabunk 2018-02-23 11-03-34.
    Metabunk 2018-02-23 11-04-13.
    When burnt produced sparks.

    View attachment 31947


    This is what I collected. HOWEVER the possibility of cross-contamination cannot be eliminated, and is quite significant in the absence of collecting very large quantities. My garage contains thousands, if not millions of microspheres.
    Metabunk 2018-02-23 11-00-32.

    Metabunk 2018-02-23 11-02-34.
  6. Nada Truther

    Nada Truther Active Member

    Are these spheres all solid, or are any of them hollow? I wonder because sometimes when I use a torch or weld I get some popping that is from the metal making a bubble and popping. This then sends a shower of sparks out in a trajectory. Is it possible that the propulsion behind the sparks is just small popping from bubbles of melted metal? I wondered about the density of the spheres to see if they were actually metal bubbles.
    Last edited by a moderator: Feb 23, 2018
  7. Mick West

    Mick West Administrator Staff Member

    I think they are mostly solid. Hard to say. There are some that do look a bit like a popped bubble, but quite rare.
  8. Jedo

    Jedo Member

    Once again, Mick, great experiments!!!

    If you look on the internet you can find some sites making experiements with steel wool, too, e.g., here one for kids:

    From there I got also the idea of igniting it with a battery, but other places have the battery ignition, too, including survival sites,

    It appears the ignition of steel wool is quite common in student chemistry labs, as the wool after burning is heavier than before. This is counter-intuitive to usual concepts of combustion, but it becomes clear when looking at the chemical reaction:

    4 Fe + 3 O2 → 2 Fe2O3,
    which is exothermic. It has no gas as product, so gas produced from the reaction as a propellent is ruled out.

    The iron gets oxidized to Iron(III)oxid. So the spheres we obtain are Iron(III)oxid, which becomes rust only upon hydration. Before hydration it does not look red but still shiny metallic. Its crystalline form is Hematite.

    So is it clear whether we are looking for microspheres of iron or of iron(III)oxid?

    The reaction rate is limited by the amount of oxygen available compared to the surface.this is also an explanation why macroscopic pieces of iron do not burn, because the low surface-to-volume ratio inhibits the reactants to come into contact sufficiently, and the energy produced by the reaction is not self-sustained.

    You can compare that with wood wool, which burns quite rapidly (and also similarily to steel wool) when ignited:

    [the wood wool is right]

    Compare that if you try to ignite a bulk piece of wood which has been planed and smoothed; it wont ignite readily. And if you manage to ignite it eventually, it will probably not burn self-sustained but go out. Only when you put the wood piece into the glow of a fire (initiated by smaller pieces of wood) that was burning for a while, it will ignite in a self-sustained way.

    So it is all about the surface-to-volume ratio that lets iron burn.*

    The difference in the surface-to-volume ration also might be an explanation for the two different processes Mick observed:
    1. smaller strands have a favourable surface-to-volume ratio for a higher combustion rate transversal to the strand, so the iron gets hot quick and forms a drop of molten iron at the end of the string, still attached. The heat produced in the drop can be conducted along the strand, and if the conduction is quicker than the reaction rate progressing of combustion along the strand the drop detaches and you get a small microsphere.
    2. bigger strands have a lower combustion rate transversally, so do not produce so much heat, but still enough to form a drop of molten iron at its end. However, heat conductivity progresses here slower than the combustion along the string, so that the drop can grow while it walks along the strand.
    This is just a hypotheses by me, but it can be tested by burning single strands with different thicknesses.

    To the question why sparks shoot away from the steel wool. I guess this results form a difference of temperature between two sides of a molten microsphere. The gas molecules that come into contact with the hotter side get more kinetic energy than those on the colder side, thus producing more pressure on that side. This pressure difference is enough to propel the microspheres for tens of centimetres.

    This could also explain curved trajectories by assuming that the microsphere got some angular momentum either from the start right away or after some collision.

    The effect is quite similar to that in the (misnamed) light mill, where the gas particles bouncing away from the hotter plate propel the mill:

    * Just an idea: Maybe the energies of the plane crash / fire were sufficient to get the iron ignition started. So perhaps the CTs were right about flows of molten iron from the Twin Towers?? :confused::confused::confused: On the other hand, this was surely checked before… [deleted after discussion with Mick, see posts below]
    Last edited: Feb 23, 2018
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  9. Mick West

    Mick West Administrator Staff Member

    I was at Home Depot, so picked up a flint striker (used for lighting gas torches)
    Metabunk 2018-02-23 14-19-18.

    Much more productive with the sparks
    Metabunk 2018-02-23 14-20-14.

    And producing a fascinating smorgasbord of spheres.
    Metabunk 2018-02-23 14-34-13.

    I suspect the clearer yellow/brown spheres are from the flint. You can see in this photo pieces of uncombusted steel and flint. There's also a great variety of spheres, which suggests combination of iron, iron oxide, and flint. Maybe other stuff too.

    Here's a closeup of two very small spheres.
    Metabunk 2018-02-23 14-41-43.

    Edit: I notice now there's some of these in the sample from the small Bic lighter, just less and smaller. Possible due to higher temps or more heat in the flint striker.
    Last edited: Feb 24, 2018
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  10. Mick West

    Mick West Administrator Staff Member

    I'm sure there were plenty of sparks, and hence more microspheres. But not enough for "flows". The larger pieces of steel would not burn.
  11. Jedo

    Jedo Member

    Yeah, I went for a shower and realized myself it was a stupid idea, but you were quicker ;).

    Initially I thought about an experiment where one stacks the small steel wool with the one used for kitchen cleaning, stacked with thin wire meshes, thicker wires, etc up to bigger steel structures, and see if this can lead to a self-sustained steel-fire (in analogy of how you make a fire in your fireplace). And then I thought something similar could have been possible in the WTCs: the crash created lots of steel splinter of all kind of sizes that would progressively ignite. But of course, the amount of oxygen necessary for the reaction is missing in both cases, so it wont work.

    Maybe that is another possible train of thought why Jones et al. started to think about (nano)thermite.

    However, having you replying not to the main part of my post, which IMO explains most of the open questions there were, but only to my outlandish speculation at the end, makes me question if I presented my thoughts clearly enough. So please let me know if I should provide further or more clear explanations for any point I have discussed above.
    Last edited: Feb 23, 2018
  12. Mick West

    Mick West Administrator Staff Member

    I suspect a mixture.

    I'm really unsure what the precise mechanism is for either formation. Consider a "wire" (in the steel wool). The surface of this wire probably has a very thin layer of iron oxide. Along comes heat. the surface of the wire rapidly oxidizes (burns) which produces more heat. What then happens to the interior of the wire? For the spark to travel along the wire the interior of the wire must either A) oxidize, or B) melt.

    My suspicion is that the interior melts, largely due to the lack of oxygen. It's now surrounded by iron oxide, and perhaps the surrounding air has been depleted of oxygen. The molten core and molten iron oxide forms a ball due to surface tension, and that is pulled along the wire.
  13. Mick West

    Mick West Administrator Staff Member

    Last edited: Sep 25, 2018
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  14. Mick West

    Mick West Administrator Staff Member

    This interesting video suggests that metal filings from a grinder are so small that they spontaneously ignite in air - a property called pyrophoricity

    Metabunk 2018-02-23 17-22-25.

    They demonstrate the creation of a tube of this iron via a chemical process, and then empty it into the air, causing it to spontaneously ignite.

    Metabunk 2018-02-23 17-28-06.

    Steel wool is not pyrophoric, but perhaps on the edge.

    Likewise with things like the grinding, it might be making particles that are not pyrophoric, but just require some heat to get there.
  15. Oystein

    Oystein Active Member

    There is no guarantee that all the iron gets fully oxidized - lots of imperfections occur. The old McCrone Particle Atlas. Part III, of the early 1970s (a standard reference for forensic microscopists; Part III covers electron microscopy and XEDS spectra) has a couple of examples of magnetite spheres (Fe3O4, iron(II,III) oxide), a mineral that, as the name suggests, is ferrimagnetic (attracted to a magnet, and can be permanently magnetized). These were found in various ashes - from coal plants to municipal waste incinerators. These would have burned above, say, 900 °C, but certainly below the melting point of bulk, pure iron.
    Chances are, if you collect spheres with a magnet, there will be many magnetite spheres, but few hematite spheres, as hematite is usually very weakly ferromagnetic.
    (Magnetism is a phenomenon I thoroughly fail to understand)

    An aside:
    As for the color of hematite: Yes, in bulk size it's black, but microparticles are brown to purple, and nearing 1 µm and the nano-range, become more and more red to orange. At some point, it becomes transparent with a red hue.
    And that is why "nano-hematite" is used as a red pigment - primer paint (including at least two of the main recipes used at the WTC) is red because of (nano-) hematite pigment. This is of course not, as Harrit and Jones feign to believe, a result of advanced, secret military-style nano-technology. Red ochre has been used by stone age cave dwellers, and has been mass-produced in low-tech industrial processes since at least the 1920s. One simple way to make nano-hematite out of coarser hematite is: grinding!
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  16. Jedo

    Jedo Member

    So when the magnetite spheres were created in the fire, do they originate from iron or steel? And if so, the reaction sets on at 900°C, but could it also be that the reaction is exothermic, too, resulting in higher local temperatures?

    You mean you don't get a spin on it? :p

    Ferrimagnetism is a sub-case of ferromagnetism, similar to anti-ferromagnetism, but opposing spins do not cancel each other out so that a net magnetic moment remains.

    Therefore I'd expect naively that hematite is more susceptible to magnetization than magnetite, especially as both have iron as elemental base.
  17. Mick West

    Mick West Administrator Staff Member

    A couple more microsphere creation mechanisms to consider, probably insignificant, but interesting to the subject in general.

    Snapping Steel. Tensile failure. I was attempting to bend a "Stanley" utility knife blade to make a temporary crucible. The blade snapped into three pieces with a small number of sparks. The sparks might have only occurred because of the brittle type of steel used in the blade, but perhaps similar sparks (and hence microspheres) would form from the tensile failure of bolts?

    Steel on steel action. Hit two pieces of steel together hard enough and you get sparks.
  18. Oystein

    Oystein Active Member

    The key words were "very weakly". It appears the net magnetic moment tends to be near zero.

    Magnetite has plenty of uses for its magnetic properties (recording tape, floppy disks of old), hematite not so much. In fact, not having a magnetic moment is probably a desirable property in pigments (although magnetite has its use as pigment, too).
  19. Jedo

    Jedo Member

    Ok, sorry, you are of course right. I was just guessing before, and my intuition is wrong. For determining what kind of magnetism a certain crystalline structure shows, you have to consider a lot of things, among them:
    1. The crystal structure and symmetries;
    2. the valence of the iron ions on different sub-lattices;
    3. the sign of the exchange energy; is it positive, parallel aligned spins are favoured and you get a ferromagnet by and large, if it is negative, anti-parallel spins are favoured and you may get anti-ferromagents,
    4. the absolute value of the exchange energy for couplings between different sublattices,
    5. other couplings like superexchange or spin-orbit coupling;
    6. frustration,
    7. etc.
    and probably more.It is really complicated.

    Magnetite has a spinel lattice, with the irons forming different sub-lattices.
    Here, oxygen ions are grey, with a tetraeder sub-lattice of Fe3+ ions (green), and an octaeder sub-lattice (blue) of Fe2+/Fe3+ ions.

    All things in the list considered above, on gets that the Fe3+ in tetraeders couple stronger negatively to the Fe3+ in octaeders than to the Fe2+ in the octaeders;

    the former constitute an anti-ferromagnet, but the latter form a ferrimagnet, so that the net magnetic moment is 4 µB (Bohr magneton)

    The crystal structure of Hematite is the same as that of corund (Al3O2), for which I included this image which shows how the lattice is built up:

    The exchange energies are here negative, too. So Hametite is an anti-ferromagnet up to -23°C. For temperature higher then that, spin-orbit coupling leads to spin-canting, leading to a net magnetic momenta due to the spin misalignment:
    The resulting net magnetic moment is 0.002 µB, so about a factor of 2,000 smaller that in Magnetite.

    So I agree that the stuff Mick is collecting by a magnet probably are microspheres which are either of pure iron or of Magentite, or at least a considerable part of the microspheres consists of either of the two. However, that does not rule out that they also contain considerable Iron(III)oxide, and that all the mechanisms that I explained above are still possible.
    Last edited: Feb 24, 2018
  20. Mick West

    Mick West Administrator Staff Member

    My toner arrived. It is non-magnetic slightly magnetic A small pile of it burns slowly by itself. The resultant "slag" is somewhat magnetic. No obvious microspheres, but some shiny bits.

    Metabunk 2018-02-24 14-51-24.

    Hard to say with all the carbon.
    Metabunk 2018-02-24 15-00-28.

    I plan a more entertaining method of burning it in a fast moving flame with magnetic capture under tempered glass.

    I wrote that toner was non-magnetic. It is actually slightly magnetic in that it will jump a few mm to a strong magnet. I previously was testing that through a glass slide, where a clump of the toner did not move.
    Last edited: Feb 24, 2018
  21. Mick West

    Mick West Administrator Staff Member

    Toner methodology:

    Metabunk 2018-02-24 15-21-40.

    Metabunk 2018-02-24 15-23-05.

    Metabunk 2018-02-24 15-24-21.

    Metabunk 2018-02-24 15-24-43.

    I collected a large amount of magnetic residue, put it on a slide and then dropped it on the carpet :(

    But managed to collect enough again from the surface of the glass (with a magnet) . Result is largely the black masses of before, but with some distinct microspheres, presumably iron rich.

    Metabunk 2018-02-24 15-54-09.

    Closeup of sphere in lower left, shows some surface detail.
    Metabunk 2018-02-24 15-59-05.

    So I'd say yes, burnt laser printed paper, and burnt toner, would contribute to the microsphere load.
    Last edited: Feb 24, 2018
  22. Oystein

    Oystein Active Member

    Most of that still flies over my head, I guess I am going with "6. frustration" :D

    But thanks anyway for the explanations and the results! And I agree of course that when you capture a particle of magnetite or iron, it will likely also contain some Iron(III) oxide.
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  23. Mick West

    Mick West Administrator Staff Member

    Another (probably minimal) source for consideration - the sudden increase in air-flow during the collapse.

    The towers were engulfed in fires over several floors just before collapse. Red hot steel would likely exist in those regions. Is it possible that a sudden, massive, and rapid introduction of air from the floors above caused some combustion of steel items? Or simply the items themselves falling though fresh air?

    Would a few seconds of hurricane force (>75mph) winds supply enough oxygen to burn some iron?
  24. Mick West

    Mick West Administrator Staff Member

    I've repeated the oldest version of this type of thing. Burning steel wool. This time I tried to catch more "sparked" spheres than "wired" spheres. To do this I suspend the wool (0000 grade) above a magnet under some paper. Sparks fell and the sphere were caught.
    Metabunk 2018-02-26 12-28-30.

    Close up after the initial burn. Lots of large wired spheres.
    Metabunk 2018-02-26 12-31-06.

    The result was quite a few clumps of spheres.

    Metabunk 2018-02-26 12-44-06.

    I suspect they would easily be separated into individual spheres with some minor mechanical action.

    There were several individual spheres. but most of them were in clumps.
    Metabunk 2018-02-26 12-47-57.
    Last edited: Mar 5, 2018
  25. Mick West

    Mick West Administrator Staff Member

    Some paint chips on a rusty steel fence. Bent where a tree fell on it.
    Metabunk 2018-02-26 13-30-24.

    Into the pot (a steel measuring cup)
    Metabunk 2018-02-26 13-31-37.

    Apply heat from below:
    Metabunk 2018-02-26 13-32-10.

    Ignition after five seconds, heat source immediately removed.
    Metabunk 2018-02-26 13-33-24.

    Burns out.
    Metabunk 2018-02-26 13-34-10.

    The result was mostly ash.
    Metabunk 2018-02-26 13-35-09.

    Some microspheres, but only small ones, and very rare.
    Metabunk 2018-02-26 13-36-47.

    Of course this was just some random acrylic paint on a very rusty fence. Still made some spheres, but nothing like welding, etc.

    The ignition was interesting. The steel was not even red hot. It might have been the gasses coming off the chips that was igniting, not the chips themselves.
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  26. benthamitemetric

    benthamitemetric Active Member

    Well, after a couple of days of experiments, I think it's fair to say that Mick has reasonably demonstrated that iron microspheres are a relatively common phenomenon in situations where an object containing iron is subjected to fire and/or one or more substantial collisions with other objects.

    Given these experiments, is there any reason to think the iron microspheres in WTC dust samples could not have been caused by fires during or after the attacks or from the torches used to construct the towers and that were ubiquitous at ground zero during the rescue and recovery period and or collisions that occurred between objects during the collapse?

    If not, I believe it is fair to say that Mick has debunked AE911Truth et al's claims that (i) the presence of iron microspheres at ground zero is evidence of the use of thermite on the WTC buildings and (ii) the creation of iron microspheres during the ignition of the chip that was extracted from the WTC dust is evidence that such chip was thermitic. All the iron microspheres seem to be evidence of is that an object containing iron was subjected to fire and/or one or more substantial collisions with other objects.
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  27. Jedo

    Jedo Member

    Have you tried thinning out the steel wool before burning it? This may, according to my hypotheses uttered above, give you relatively more microspheres. Have you tried burning a single strand of steel wool? How about two single strands intertwined, etc?

    Another suggestion: why don't you catch the microspheres in a steel bowl, old cooking pot, or ceramic pot? In the students lab experiments for comparing the weight of steel wool before burning with the remains after burning, they need to catch everything, so they usually use some ceramic bowl. That would also to determine whether there are non-magnetic remains, or if all that you catch is magnetic.
  28. Jedo

    Jedo Member

    I agree with that. However, I can't believe you want to stop Mick experimenting just shortly before the shipment with the Thermite reactants arrives:

    • Funny Funny x 1
  29. Nada Truther

    Nada Truther Active Member

    To add to that.... Could we not also assume that, even if there were some microspheres created by thermite use (hypothetically), there would definitely be some present from the grinding and cutting during the clean up, in addition to the left over spheres from the initial grinding/cutting/welding during construction? This would then mean that from all of the material collected for testing that contained the microspheres, not all would be from thermite. The amount of spheres from this massive use of thermite has now dwindled to much less. With all of this talk of how Iron rich micro spheres can easily be created by a multitude of other means, other than thermite..... Is there a measure of how much microsphere residue would be created from the use of thermite? If there was a massive amount of thermite used, there would be a significant amount of residue and micro spheres from the thermite. If the calculations would show that we should have "X" amount of microspheres present, and there is much, much less, wouldn't that, by Truther logic, mean that the opposite must be true and there was no thermite used?
  30. benthamitemetric

    benthamitemetric Active Member

    Haha, I wouldn't dream of asking Mick to stop the experiments. I think they are extremely powerful tools for both discovery and didactic purposes. If nothing else, I was hoping to perhaps coax someone predisposed to defending AE911Truth's claims to join the thread so that Mick could make sure the experiments were addressing the best arguments. As has been the case in many a recent thread, however, the usual defenders of AE911Truth's claims have gone silent. If you take the silence as implicit acknowledgement of a lack of a counter argument, that's great. But if it's just indicative of a "take my ball and go home" dismissal of these experiments by AE911Truth's proponents (and I know this is not mutually exclusive to the lack of counter argument), then I think it's worth trying to reengage with them and make it clear to the casual browser who may be on the fence that such people have the opportunity to present their cases too.
  31. Mick West

    Mick West Administrator Staff Member

    Two bits of rusty rebar, one with aluminum foil wrapped around it:
    Metabunk 2018-02-27 15-30-28.

    Bang them together rapidly and you get a thermitic reaction between the aluminum and the iron oxide, creating sparks.
    Metabunk 2018-02-27 15-31-57.

    Not a lot with this setup, however the better demonstration is done with two rust iron balls - presumably the greater mass and contact surface area creates more sparks. Example:
    Metabunk 2018-02-27 15-33-23.

    Is it plausible that the aluminum cladding and the steel building structure created some sparks during the collapse, and maybe the impact. That would create iron microspheres.
    (This was mentioned in the older thread: https://www.metabunk.org/debunked-iron-microspheres-in-9-11-wtc-dust-as-evidence-for-thermite.t2523/ )
  32. Jedo

    Jedo Member

    Is it necessary to have iron(III)oxid–aluminium–iron(III)oxid or would two of them suffice?

    How about hitting the iron against a massive aluminium bar or vice versa? I doubt that much will happen in that case just as bulk iron does not burn. The foil is probably thin enough to enable the reaction, in contrast (presumably) to bulk aluminium.
  33. Mick West

    Mick West Administrator Staff Member

    The reaction uses a 1 aluminum to 3 Iron Oxide ratio by weight, so I suspect the "sandwich" method is actually needed to get that mixing ratio over a sufficiently large area. The cannonballs will compress the aluminum foil to very thin shreds, mixing with copious amounts of iron oxide on both sides.

    So really that does not seem that plausible as a WTC mechanism.

    I've got a 1/2" solid aluminum rod, and so far have not been able to get a single spark out of it from all the rusty things I've been hitting it with.
  34. Mick West

    Mick West Administrator Staff Member

    3 grams red iron oxide + 1 gram of aluminum powder in a bit of foil
    Metabunk 2018-03-01 18-22-00.

    The magnesium strip, it does nothing.
    Metabunk 2018-03-01 18-23-11.

    Perhaps more direct heat?
    Metabunk 2018-03-01 18-24-10.

    Holy .... !
    Metabunk 2018-03-01 18-24-53.

    Back away!
    Metabunk 2018-03-01 18-26-02.

    Metabunk 2018-03-01 18-27-32.

    Other side of 16 gauge steel (1/16" thick. 1.6mm)

    Metabunk 2018-03-01 18-27-59.

    Collected with magnet = Sphere-a-palooza!
    Metabunk 2018-03-01 18-28-48.

    More later.
    Last edited: Mar 1, 2018
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  35. Mick West

    Mick West Administrator Staff Member

    I suspect the white is magnesium oxide. The fuse was magnesium, but did not burn very well, and fizzeld out, just coating everything with white powered (magnesium oxide)

    What's interesting is the sheer variety of sphere. Mostly large, and mostly not metallic looking. Lots of hollow spheres:
    Metabunk 2018-03-01 20-35-52.

    Lots of irregular spheroids
    Metabunk 2018-03-01 20-36-24.

    A variety of hybrid types - part metal, part mineral.
    Metabunk 2018-03-01 20-38-26.
    These look at first like a "cap" of metal, but I think it's actually a metal (iron) sphere partly inside a mineral (magnesium or aluminum oxide) sphere. Which suggests some of the other white spheres will have an iron core.

    So a fascinating collection. I think the question raised here is what type of signature of microspheres would you expect if thermite or nano-thermite was used to cut columns. What would it be contained in? What type of spheres would that form?
    Last edited: Mar 1, 2018
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  36. Mick West

    Mick West Administrator Staff Member

    Here's part of the blob that remained. It can only be composed of the combustion products of the aluminum powder, iron oxide powder, magnesium strip, and aluminum foil. It was burnt on a steel plate. Presumably ignited by the propylene torch igniting the last bit of magnesium.
    (Blue lines are 1mm wide).

    Here's the underneath.

    Spheres in the flake. In the 100 to 1000 µm range (0.1 to 1mm)
  37. Mick West

    Mick West Administrator Staff Member

    That was 4g of thermite. I've got 3,000g left.
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  38. Mick West

    Mick West Administrator Staff Member

    Some temperatures, in Fahrenheit

    2500-2750° = melting point of steel
    2800° = melting point of iron
    2849° = melting point of iron(III) oxide
    3762° = melting point of aluminum oxide
    >4,000° = Burning temperature of thermite
    5166° = Melting point of magnesium oxide

    This suggests the white spheres are aluminum oxide, from burning of the aluminum foil I used as a container. [Edit: more likely from the actual product of burning thermite][/B]
    Last edited: Mar 3, 2018
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  39. Jedo

    Jedo Member

    Converting that into Communist Celsius temperature units °C

    1400 °C = melting point of steel (2% carbon)
    1538 °C = melting point of iron
    1565 °C = melting point of iron(III)oxide
    2072 °C = melting point of aluminium oxide
    <2500 °C = Burning temperature of thermite
    2852 °C = Melting point of magnesium oxide

    and we have from the Magnesium article on Wikipedia
    So maybe you should do a cross-check by burning the magnesium strip alone, looking for MgO or Mg microspheres.

    However, I doubt the white spheres are a pure Magnesium oxide or Aluminium oxide, as you managed to pick them up with a magnet. Both substances are diamagnetic, i.e. not attracted by a magnet. So they must have an iron (or iron oxid) core.

    AND: Please keep safe during experimenting, use some proper safety clothing (at least no polyester), wear safety glasses, and use maybe also a crucible (ceramic pot or so).
  40. Mick West

    Mick West Administrator Staff Member

    I'll try burning some Mg and Al together.

    I had safety glasses and a hose for after-fires (it has just stopped raining though, so the nearby environment was safe). I knew that 4g was going to be relative low energy. If I do it again though I'm going to wear my full welding gear.

    Regarding crucible, with the nanothermite WTC controlled demolition, presumably there would be something containing the nanothermite, holding it against the steel. Since none were found in the rubble then is it safe to say they would have been consumed by fire? Dustified? Turned into microspheres of ???
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