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Author: Subject: Exotic thermites & analogs
Mardec
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[*] posted on 19-9-2007 at 06:36


xD

:mad:

I hate when something doesn't work...

I made TH-3 thermite today, the same shit the military uses. I lit perfectly like it should. Burned very intense. Left a big pile of molten metal (Iron probably).

But it didn't get through a small (emty) gas container for my bunsen burner.. The iron stayed on top...

I don't get it, why didn't it go through it? Everything in the facinaty was charred.

I used this comp:

-12 g Fe2O3
-4 g Al
-6 g Ba(NO3)2
-0,2 g sulpher.

I lit it with 50/50 kno3/mg and the whole charge was packed in a 1,5 cm ID carbboard tube with the burning side directly aimed against the bottom of the gas container.

And it didn't even made a small hole.

The container was emty yes, I am not a noob/stupid.

It was one like this: http://content.answers.com/main/content/wp/en-commons/thumb/...

What are these things?! there was an aluminum can holding the tube in place, that completly vanished.

[Edited on 19-9-2007 by Mardec]
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12AX7
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[*] posted on 19-9-2007 at 13:34


Try using more. Like, 10 times more.

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[*] posted on 19-9-2007 at 20:53


I've always found thermite to rarely live up to the legend of burning through engine blocks and all that. Even relatively thin steel just gets a slight indent and a big pile of molten iron. About the best I've done is cracked a cast iron frying skillet. That took about 300 or so grams. That wasn't the most ideal thermite though. It was a demo in my chemsitry class. It was the thermite that is sold as by Fischer Scientific.
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[*] posted on 19-9-2007 at 21:19


Thermite does not live up to its legend. I once did a test comparing standard stoichiometric thermite to 60/40 CaSO4/Al
10 g of each on identical pickle jar lids(thin steel). The thermite burnt the paint, wheras the cast CaSO4/Al melted a one inch diameter hole. Mind you, the thermite was with very fine oxide and aluminum, so it burnt very fast, and left minimal slag, I never actually got molten iron.




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Mardec
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[*] posted on 20-9-2007 at 00:32


Hmm, I thought it would be something like this.

But I am not a very rich pyro so I always try to get maximum bang for the buck. That is why I use small amounts.

CaSO4 sounds interesting.

Btw, I read Fe3O4 thermite is 4 times more potent than Fe2O3 (wich I used). Is this true?.. That would explain the crappy results from Fe2O3. And how Would FeO do?

And what is the most powerfull thermite mixture without very exotic oxides?

Btw, my aluminium was 250 mesh atomised, is this to thick?!
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12AX7
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[*] posted on 20-9-2007 at 01:16


Fe3O4 contains a few percent less oxygen than Fe2O3, and has slightly higher binding energy. That it is ANY bit more powerful is bull, and that it's four times as power is bull shit.

Is CuO an exotic oxide? CuO + Al (approx. 3:1 by weight, IIRC) burns like flash powder and is shock sensitive.

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[*] posted on 20-9-2007 at 04:35


MnO2 + Al also makes a very fast thermite, which is relatively easy to ignite. Obtaining MnO2 is easy. You can buy it at pottery/ceramics stores.



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Mardec
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[*] posted on 20-9-2007 at 09:17


Quote:
Originally posted by 12AX7
Fe3O4 contains a few percent less oxygen than Fe2O3, and has slightly higher binding energy. That it is ANY bit more powerful is bull, and that it's four times as power is bull shit.

Is CuO an exotic oxide? CuO + Al (approx. 3:1 by weight, IIRC) burns like flash powder and is shock sensitive.

Tim


CuO isn't exotic, it is expensive.. But I do have some, but I can't seem to light the thermite with CuO (homemade)

Is 250 mesh to thick?!

I couldn't light the normal thermite either, but the TH-3 comp did light.

Maybe I should get better Al.


And omg http://en.wikipedia.org/wiki/Thermite The guy who wrote this is so stupid, and I believed it at first look.. Yeah the Fe3O4 lookst stronger in the equation. Only the reaction is with 4 times more Al then the Fe2O3 one. Fe2O3 thermite is stronger indeed... nice

I think about ordering 400 mesh uncoated Al for thermite.

Quote:
Originally posted by woelen
MnO2 + Al also makes a very fast thermite, which is relatively easy to ignite. Obtaining MnO2 is easy. You can buy it at pottery/ceramics stores.


Does MnO2 make stong thermite? MnO2 seems to obvious..

[Edited on 20-9-2007 by Mardec]
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[*] posted on 20-12-2007 at 06:04


Quote:
Originally posted by The_Davster
60/40 CaSO4/Al

Al2(SO4)3/Al works nicely too, and you can make that by adding H2SO4 to Al powder and warming it with a low flame until the first reaction turns it into a foamy concrete-like substance. Then it ignites easily from a propane torch. I made a thread about it a while ago. However, the reaction is extremely quick, like a flash powder--due to the fact that the Al is a powder. I don't have a source for larger mesh Al :/
How did you get anhydrous CaSO4?

[Edited on 20-12-2007 by Nixie]




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[*] posted on 20-12-2007 at 12:55


I just used plaster of paris
The exact procedure is on NickF's website:
http://flashbangboom.homestead.com/yields_etc.html
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[*] posted on 20-12-2007 at 13:05


Quote:
Originally posted by The_Davster
I just used plaster of paris
The exact procedure is on NickF's website:
http://flashbangboom.homestead.com/yields_etc.html

"Bake it in the oven at gas mark 1 for a few hours...then increase the temperature to gas mark 2 or even 3"
Huh? WTF is "gas mark #". Any oven I have, or for that matter have seen, has the temperature specified in degrees Celsius or Fahrenheit. How do I figure correspondence? Would "mark 1" be something like 70*C or more like 110*C or what?

I'm curious how the energy output from using the calcium sulfate compares to using the aluminum sulfate instead.
Preparing the aluminum version is easier and much, much faster (well, assuming you have sulfuric acid, but almost anyone can easily find the drain cleaner version).

[Edit:] Some stuff on that site doesn't make sense. For example:
"11) Allow the Sucrose Nitrate to dry at room temperature. This can be done very quickly if it is softened at 30*C and rolled into a <b>ball</b>, so that it has a <b>low surface area : volume ratio to speed up drying</b>."

LOL wut?!

[Edited on 20-12-2007 by Nixie]




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[*] posted on 20-12-2007 at 13:48


I put it in the oven at around 120C for several hours.
I was worried about ignition, but without cause, as a propane torch had no effect on a small piece.
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[*] posted on 20-12-2007 at 18:53


Calcium sulfate at 120C? Not much; 3/2 H2O comes off around 200C, and the remaining 1/2 H2O around 600C.'

Sodium sulfate is easier to handle in this regard, and makes an awesome orange flare to boot. :P

Tim




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[*] posted on 14-1-2008 at 02:29


I am going to try TiO2 thermite. Now I am balancing the equation and I remembered someone saying you will never get pure Ti out of this thermite. Only TiO.

So should I use TiO2 -> TiO or TiO2 -> Ti
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[*] posted on 15-1-2008 at 11:23


I do not discount the notion that it is possible to obtain Titanium metal from a thermite reaction, however in my experience it has shown to be difficult to achieve.

In my experience TiO2 + Al, stoichiometrically balanced (assuming Al2O3 and Ti metal products), thermite reactions do not appear to be successful in producing Titanium metal. Instead, what I end up with was a dark / blackish lump of fused material with nothing to indicate the presence of elemental Titanium.

Initially, I thought that this black material must be Titaium(II) Oxide, TiO, and that the Aluminum powder was not successful in reducing the TiO2 all the way to Ti metal but instead stopped half-way. I based this assumption on incomplete / incorrect information concerning what color certain Titanium Oxides should be. Of course, TiO2 is white. But it turns out that TiO is actually golden-yellow colored, so obviously the black stuff could not be TiO. A far more likely candidate for the black product of the TiO2 thermite reaction would be Titanium(III) or Titanium(III, IV) Oxide since these are supposed to be dark-violet and black colored, respectively.

In order to get some experimental evidence to back up this assumption which was based solely on the color of the product of the thermite reaction, I tried to reduce the (what I am assuming to be) black Ti3O5 further with a more reactive metal…Magnesium [ribbon]. By pressing a lit piece of Mg ribbon against a sample of the black material, it appears that I was successful in reducing the oxide further since the area around the burning Mg ribbon turned yellowish-gold…the same color TiO should be.

So if one wanted to obtain Ti metal from a thermite reaction, one will probably need to increase the amount of reducing agent in the mixture since apparently (in my experience) a straight stoichiometric ratio does not quite cut it. Also, one might need to use a more active metal than Aluminum…possibly Magnesium instead for best results.
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[*] posted on 16-1-2008 at 07:51


Wow that is a really nice reply!. I will try it, I am going to use german dark as reducing agent. I can get it cheaper than 400 mesh aluminum powder so why bother with the coarser stuff.

I will try one stochiometric and one with a excess of aluminum. I will post the results here afterwards.
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[*] posted on 16-1-2008 at 10:25
Anybody for nanoscale thermite reactions?


This might belong in a thread to itself, but it certainly qualifies as an "exotic thermite" in my opinion:

http://www.physorg.com/news119702507.html

"Mixing a low-density composite of copper oxide nanorods (fuel) and aluminum nanoparticles (oxidizer) results in a large contact area between the fuel and oxidizer. On the nanoscale, the low density and large contact area of the nanothermite composite can lead to a fast-propagating combustion." In fact, they're talking about combustion waves propagating at 1500 to 2300 m/s, in the Mach 3 range.

I'm very fuzzy on how they propose to deliver and trigger these mixtures for cancer treatment -- it sounds like they're using the shockwave from the reaction not to disrupt cancer cells directly, but to induce cells to take up a chemotherapeutic drug.
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[*] posted on 16-1-2008 at 13:48


Quote:
Ursprünglich verfasst von -jeffB
Mixing a low-density composite of copper oxide nanorods (fuel) and aluminum nanoparticles (oxidizer) results in a large contact area between the fuel and oxidizer.


Thats strange. Copper oxide cant be the fuel, and aluminum won't oxidise anything. Is this a journalistic failor, or may this whole article be some kind of hoax?
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[*] posted on 16-1-2008 at 17:39


Quote:
Originally posted by Norrys
Quote:
Ursprünglich verfasst von -jeffB
Mixing a low-density composite of copper oxide nanorods (fuel) and aluminum nanoparticles (oxidizer) results in a large contact area between the fuel and oxidizer.


Thats strange. Copper oxide cant be the fuel, and aluminum won't oxidise anything. Is this a journalistic failor, or may this whole article be some kind of hoax?


I think it was more likely just an accidental transposition. (It slipped past ME, oops.) Here's a direct link to another pub from this group, with another application of the nanoengineered thermite:

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=n...
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[*] posted on 16-1-2008 at 19:57
SiO2


None of my SiO2 based thermites worked at all..

As chemoleo did, I tried with homemade very fine SiO2 ppt from a failed silica gel making attempt ..
I tried to mix several ratios , but neither of these did propagates on it's own.. The only way was to mix one part of this thermite with 2 parts of Fe2O3 thermite..

Chemoleo, in your early attempt you have used sulfur/SiO2 or S/Al/SiO2 ??? What the ratios(if you didn't have used the same of the S.C. Wack reference)?

[Edited on 17-1-2008 by Aqua_Fortis_100%]




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[*] posted on 17-1-2008 at 06:58


I was able to get a SiO2 thermite reaction going using a mixture of Silicon Dioxide, Aluminum powder, and Sulfur in the ratio of 9 : 10 : 12 by weight respectively.
Afterward, I was left with a larger, porous, blob of elemental Silicon.

I used ordinary “sand” (unknown particle size, but there was nothing particular special about it) as my SiO2 source, 90% garden Sulfur, and ~200 mesh Aluminum powder.
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[*] posted on 17-1-2008 at 12:36


Thank you, mrjeffy321

I will try latter that and post results..

But will sulfur react with al least some of the silicon metal produced (maybe producing some sort of sulfide)? If yes , how to purify it? Maybe simply putting the cake in HCl will be too easy to be truth: probably gives H2S and the Si chloride will decompose in SiO2 which will mess with your final product..

There is a way to go only with sulfur and SiO2, without wasting aluminium , or it's also too easy to be truth?

Thanks




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[*] posted on 17-1-2008 at 13:06


There's enough Al to burn the S, obviously. (SiS and SiS2 are known, but not likely, and definetly not as stable as Al2S3.)

Silicon has a metallic appearance, so for lack of words, it might as well be called "metal".

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[*] posted on 17-1-2008 at 18:46


For making silicon element from quartz sand, check this:
https://sciencemadness.org/talk/viewthread.php?tid=2030&...

All the details are there!




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[*] posted on 18-1-2008 at 15:26


Yeah! This works fine!

Moments ago , I tried, but since I still dont have a good scale for measure very small amounts of reagents, I followed this procedure using volume comparations.. This is mainly because which my aluminium (bronzing powder) is very expensive..

I used about 1 teaspoon of each element (slightly less for sulfur) and mixing was very easy because all substances were very fine , specially the bronzing powder and the homemade ppt SiO2.. Then I've put the mix on a iron plate and ignited it even more easily with a match.. The burning is nice , but are far less quick than other thermites I've made before..
Damn , pretty nice reaction!


Tim,
Ouch, please sorry, dont consider what I've said :(
I'm was so accustomed with the term "metal" used in several and most common metallic based thermites with I forgot entirelly which silicium isn't really a metal , even having some metal characteristics , but a "weird" element ..

Chemoleo,
Good link! I didn't see this thread before..

Although , I will probably dont realize that purification procedure said in that thread, because of fluor compounds described , which are hard to come be and some like HF very watched by police and nasty as well..

Next probably will be try with B2O3 based thermite and after play with some elemental Boron ..
:D

[Edited on 18-1-2008 by Aqua_Fortis_100%]




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