Thermite made from uncomon chemicals

[Ralph]

I have to challenge the credibility of the person speaking in the film and the makers of the film as they discredit them selves as being knowledgeable with in the first 15 seconds by saying themite is an explosive many times. they are just talking about tradition Fe₂O₃ Al thermite mixed with water (or possibly some kind of binder (like what the paint is made from) they than go on to say that once it drys it becomes a high explosive. also they are talking about finding explosive residues the reaction products of thermite are aluminium oxide (of which there would be an abundance from aluminium in the building and of the plane oxidising at those high temps) and metallic iron (which the building was partially construed of. there is a chance they were refering to thermate and not thermite which is really just thermite mixed with barium nitrate and a binder. thier somewhat idiotic thermite test showed nothing accept that thermite will burn it didn't do any damage to the beam. Im not giving my opinion on weather 9/11 was as reported or as the conspiracy theorists say Im just saying that documentary is a load of crap

[Cookieman]

I have to challenge the credibility of the person speaking in the film and the makers of the film as they discredit them selves as being knowledgeable with in the first 15 seconds by saying themite is an explosive many times. they are just talking about tradition Fe₂O₃ Al thermite mixed with water (or possibly some kind of binder (like what the paint is made from) they than go on to say that once it drys it becomes a high explosive. also they are talking about finding explosive residues the reaction products of thermite are aluminium oxide (of which there would be an abundance from aluminium in the building and of the plane oxidising at those high temps) and metallic iron (which the building was partially construed of. there is a chance they were refering to thermate and not thermite which is really just thermite mixed with barium nitrate and a binder. thier somewhat idiotic thermite test showed nothing accept that thermite will burn it didn't do any damage to the beam. Im not giving my opinion on weather 9/11 was as reported or as the conspiracy theorists say Im just saying that documentary is a load of crap

 

 

I thought it was odd to when they mentioned thermite as an explosive.Though looking at the footage of the towers collapsing, it does look somewhat of a controlled demolition.

[Peret]

For what it's worth, here is a link to the original paper on the alleged thermite dust (pdf). Much more can be found by Google but it's all derivative from this.

[Cookieman]

Thanks for that Peret.

[MadMax]

Ok, I am curious about something. I've been doing some looking and the so called nano scale thermite they are referring to is actually the standard red Fe2O3/Al mix but mixed at the nano scale. The result being a much higher burn rate. Maybe not explosive but then who really knows? I mean it's not like you can just go to the hardware store and ask for nano-scale Al powder.

 

The government has supposedly been doing research on MIC's - metastable intermolecular composites. The super thermite being one of many different MIC's currently being investigated.

 

Having seen the difference in reactivity between milled and unmilled BP I can attest to the huge difference that particle size and intimacy has on burn rate. The way I understand it is that in mixtures some of the energy of the reaction gets taken by the work being done to "move" the reactants to each other. Not only does this sap energy but it also makes the reaction take much longer since conglomerations of millions of atoms in the form of particles could only react 1 layer of atoms at a time striping away layer after layer until the particle is consumed.

 

My question is this...

So if Al was mixed with Fe2O3 so friggen intimately that reactable atoms were literally neighboring each other what would be the effect? Would it explode or just burn fast? Could it be detonated?

 

I think I might liken it to TNT or RDX or something. A monomolecular molecule containing both fuel and oxidizer in 1 molecule. Can deflagrate at the flame front speed but will detonate it a shockwave passes through it.

 

Now, I know I've seen a demonstration before where someone bashed a pair or rusty iron balls together sandwiching a piece of Al foil between them and sparks shot out everywhere so that tells me that at the atomic level thermite could potentially be sensitive to shock but perhaps not unless mixed super-evenly.

 

Does anyone have any opinions about this? Has anyone ever had any experiences with any nanoenergetics or any nano scale materials for that matter? It's something I'm interested in but you really just can't find any examples of this online anywhere. It's as if it's some sort of a myth.

Edited March 11, 2011 by MadMax

[Mumbles]

Some parts of this are okay, some parts really should be reserved for the HE section.

 

The only difference between burning fast, and exploding is the container with regards to deflagration. In some cases air can be sufficient containment, such as in the last of self-confinement in flash powder for instance. If you had an infinitely fine mixture of thermite, it would burn quickly still, but not to the point of a single molecule. There is still a rate limit based on how fast the heat can transfer through the mass, as it is a deflagration in my mind.

 

It's all a subject of initiation barriers. Energy is energy. This is why you can smack a rusty ball with another rusty ball covered in foil and see a minor thermitic reaction. Thermite, of all types, is sensitive to shock. This is very evident with people using CuO/Al mixtures for exploding targets.

[brimstoned]

I was going to go simply off the activity series, which says it wont work, but I figured I better get some real data too. Zinc might be a good metal choice if you want to keep it vaguely exotic. There arn't a lot of commonly available pure zinc stocks that I know of.

 

Say Mumbles, how would you rate the purity of the zinc inside 1983+ pennies? Some years ago I cast electrodes and made a powder that worked acceptably....

[brimstoned]

I was going to go simply off the activity series, which says it wont work, but I figured I better get some real data too. Zinc might be a good metal choice if you want to keep it vaguely exotic. There arn't a lot of commonly available pure zinc stocks that I know of.

 

Say Mumbles, how would you rate the purity of the zinc inside 1983+ pennies? Some years ago I cast electrodes and made a powder that worked acceptably....

[Mumbles]

It's probably quite pure. What I was saying was that there aren't too many things that are made from pure zinc in the same way that you can't help but to find things made from mostly pure aluminum, steel, and in some cases magnesium. Zinc seems to mostly be used as a galvanizing coating or in alloys. At the time I was probably unaware of zinc sacraficial anodes, and never thought about pennies. I was mostly speaking in context to the thread being about thermite being made from more uncommon materials. Zinc powder itself is quite available actually.

[brimstoned]

Indeed, though the weight of the material makes shipping costs high.

Melting pennies is a little way of reducing inflation! ;-j

I'm currently dissolving some in 25% Chinese vinegar to see if it can be used as a fuel.

[ANFO]

A list of probably most possible thermites: Here

 

Even has molybdenum(IV) oxide/Al

and vanadium(V) oxide, which has an enthalpy of ΔH = -3726.7 kJ (total change including energy released when they solidify) which is the most exothermic I've ever seen.

Another cool point, this guy ignites a lot of his thermite with suger/potassium chlorate mix, which I didn't know you could do. And apparently you can also ignite thermite with potassium permanganate and glycerine? Anyone tried either of these?

Edited August 20, 2012 by ANFO

[taiwanluthiers]

Anything that gets fairly hot can ignite thermite, although I don't know if bp is sufficient (probably not). I know potassium permanganate and glycerin can ignite thermite, it has a delay of around a minute too. I use a slow flash mixture (50/50 mix of potassium perchlorate and spherical aluminum) to ignite thermite. You can use sparklers too.

[Blackthumb]

Burn some amonium dichromate for the 'volcano' demonstration and then use the ash w/Al for thermite...works well....leaves a nice 'button' of chromium

 

[hindsight]

_{Just read taiwanluthier's comments above about igniting thermite with KMnO4 and glycerin, and it brought back memories of the dozens of times I used this combination as a kid with impunity. Cookieman has already written about the hazards of KMno4 flash in the Flash Powder Safety topic. It only now occurs to me that what I did was appose fine aluminum (?mesh) against KMnO4 and allowed it to ignite. Does that raise any eyebrows here?}

[NeuroticNurse]

Copper Oxide thermite is awesome. Burns real quick and the sparks look great.

 

As far as igniting the stuff goes, I use plain sparklers, or occasionally, rocket candy with a few bits of magnesium and iron powder in it.