Sciencemadness Discussion Board - Exotic thermites & analogs

Exotic thermites & analogs

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chemoleo - 23-7-2004 at 18:31

Axt, I tried to download the two last movies, but connection was refused.
Are u saying no detonating force was detected on the steel plate? I remember doing exactly the same thing, CuO/Al, and it literally obliterated the container (Fe cans). Couldnt find fragments thereof, and this was in the snow, where fragments should be found easily.
Also, I presume you mean 100g, rather than 100 ml.... (sorry I dont want to split hairs, but it's an important difference)

Also, could you please explain what ' with a .25-06 charge' is?
There are a few non-American members here, so your units may not mean much to us

[Edited on 24-7-2004 by chemoleo]

Axt - 23-7-2004 at 18:41

Its a geocities problem, note that its trying to pull the movies from some "us.share.geocities ... " or whatever, just have to wait it out as geocities has gone to shit lately, whenever it tries to "share" it doesnt.

Correct that no marks at all on the plate, lot harder then a confined can (assuming you put it into it), but looks very pretty. It was 100ml volume.

Im not American! .25-06, .30-06 necked down to .25 calibre. Quite a powerful rifle, not charge

that be why I said targets.

IPN - 23-7-2004 at 22:15

Thanks chemoleo

I used Zn as I have no Al powder. I will try to make some today and also a few more tests. V2O5/Zn (or Al if I am able to make some) should be interesting.

PS. Does anyone know any video converter what could make AVI/MPEG files from MOV files? I tried Video Workshop but it just gave me errors.

vulture - 24-7-2004 at 01:33

IIRC, adobe premiere can do that.

I might try P2O5/Al "thermite" if I'm feeling lucky...

IPN - 24-7-2004 at 03:52

I tried to make some Al powder from Al plates by grinding them with an anglegrinder, but the powder was too coarse and the mixtures made with it didn't burn at all.

So I was back to Zn.

First was Pb3O4/Zn. It burned very fast and ignited a second after the fuse had gone out.

Thanks vulture, I'll try to find that

halide-salt thermites

halogen - 24-7-2004 at 07:06

If K2O/Al works, how about
3NaCl + Al --> AlCl3 + 3Na ?
Maybe a reaction between
3SnF4 + 4Al --> 4AlF3 + 3Sn
Halide thermites mitght work better than regular ones. Especially fluorides.

BromicAcid - 24-7-2004 at 10:31

Formation of aluminum oxide is very exothermic, the chloride is not, therefore thermites the yield aluminum chloride are usually not self sustaining as they are endothermic. Your reaction of sodium chloride with aluminum for example is endothermic by about 529 KJ/Mol and therefore would not commence except by constant heating and probably slowly, only driven by the AlCl3 vaporizing off.

The fluorides though are a different story, whereas the chloride only has a heat of formation of -704.2 KJ/Mol, the fluoride has more then double it, with a heat of formation of -1510.4 KJ/Mol so if you find a fluoride to go with it, with a comparatively low heat of formation you might have a good mix, however fluorides usually don't have a low heat of formation. I could not find the heat of formation of stannic fluoride so I couldn't get the numbers to crunch the reaction you mentioned, however silver (I) or (II) fluoride might prove to be quite exothermic, I've heard good things about using PTFE as well. But these are just the numbers talking.

chemoleo - 24-7-2004 at 10:49

IPN, I am a little disturbed by your reactions - for one thing, the paper directly bordering the mix didnt even burn! Can't be high temps at all!
Then -the fact you get so little smoke is also due to that - low temps.
A more interesting question though - did you play at all with the reaction products?
in the case of V2O5, you should have very very fine vanadium lying about, because the melting point of V is surely higher than the temperature of hte reaction. ZnO is probably dissolved by acetic acid, while the Vanadium isnt , so that should leave you with fine V!
Potentially the same goes for some of the others.
Regarding the TiO2 oxide, it didnt work presumbly the oxidation enthalpy of TiO2 is greater than that of ZnO.
Al from the angle grinder - hmm - I tried this once too, but because it gets so hot it has a massive oxide layer. If you really cant find Al (which would be surprising because you have V2O5 etc), you can always make it in a blender with oil and such.

How did you ignite the mixes? Were they all stoichiometric (I am asking becuase of the colour being much grey-er than I am used to with my Al thermites)
I.e. the V2O5 is a beautiful orange normally...

Saerynide - 24-7-2004 at 10:58

I noticed the paper too. I was also wondering why there wasnt any molten metal. It just kinda looks like a pile of hot powder. KMnO4 + glycerin looks like it burns hotter than the Sb4O6 and V2O5

[Edit]: Isnt the CuO/Zn supposed to be quite violent?

[Edited on 24-7-2004 by Saerynide]

IPN - 24-7-2004 at 13:22

I used the following amount of chemicals.

Zn + CuO -> Cu + ZnO
6.5g Zn to 8g CuO

3Zn + Fe2O3 -> 2Fe + 3ZnO
20g Zn to 16g Fe2O3

2Zn + MnO2 -> 2ZnO + Mn
13g Zn to 8.5g MnO2

4Zn + Pb3O4 -> 3Pb + 4ZnO
4g Zn to 10g Pb3O4

6Zn + Sb4O6 -> 4Sb + 6ZnO
10g Zn to 15g Sb4O6

5Zn + V2O5 -> 2V + 5ZnO
14g Zn to 8g V2O5

I also noted that the temperatures were quite low as only very little of the metals formed had vaporized. Most of the smoke was then of course ZnO.
I actually did save the more interesting metals (vanadium, manganese and antimony). I'll add some acetic acid to them tomorrow.

I guess normal vinegar (10%) will do?
Thanks for the info on TiO2. I thought that it was just the high melting point.

Quote:

How did you ignite the mixes? Were they all stoichiometric (I am asking becuase of the colour being much grey-er than I am used to with my Al thermites) I.e. the V2O5 is a beautiful orange normally...

I used ordinary visco grade fuse with a little knob of black powder on the end. If that didn't work I used my propane burner.
According to my calculations all the mixes were stoichiometric though they might be wrong..
The color is probably because my Zn powder is gray compared to dark Al powder and the Zn powder makes everything gray, even in small amounts

Axt - 25-7-2004 at 07:35

Quote:

Originally posted by chemoleo
Axt, I tried to download the two last movies, but connection was refused.

Seems to be an ongoing problem with other movies as well, some now in uploads on FTP2 as "Axt_Movies" should work.

hodges - 25-7-2004 at 14:35

Speaking of zinc, a month or so ago I got the idea to produce fine zinc powder from old flashlight batteries by electrolysing the zinc and collecting the finely deposited zinc tree on the cathode. This appeared to work well, and the amount of ampere-hours required to move all the zinc from the anode to the cathode was quite close to what I had calculated.

Unfortunately, as the wet zinc power was drying (I washed it first), I noticed it was bubbling some. By the time it was completely dry several days later, I found I had mostly ZnO instead of Zn. Apparently zinc in that finely divided of a state reacts with water, so preparing fine zinc this way does not work.

chloric1 - 25-7-2004 at 15:34

Quote:

Apparently zinc in that finely divided of a state reacts with water, so preparing fine zinc this way does not work.

hodges- I would dry acetone with anhydrous Magnesium or sodium sulfate and then apply this to your zinc powder. If you have access to Argon or Nitrogen welding gas put the acetone soaked sludge into a tube and blow the inert gas through it. The end the tube should have a porous block to prevent the zinc from flying out. Let me know if this works.

HNO3 - 15-11-2004 at 20:27

1) I tried V2O5/Al. it worked---but the steel "condiment cup" I used was melted through from where the top of the mixture was. I was using about 30g of mix in stochiometric porportions to the nearest g(my scale is junky and lately died

).

2) DON'T DON'T DON'T use lithium. It will likly blow up/burn your house, shed, etc down to the ground-not to mention blind you. I know----I've ignited it before ON STONE--and it left a permanent white mark on the stone.

3) In my experience the lithium forms a black nitride, which then changes to a white oxide. lithium

4) I always use magnesium ribbon from here. Unless you have lots of impurities it will always work.

PS thats where i got my V2O5 too- and a lot of my other chems.

[Edited on 11-16-04 by HNO3]

Speed of burning depends on mesh/mixing?

Mickhael - 19-11-2004 at 19:18

Ok, couple things;
Number one is I was talking to an experienced pyro, who said one of the best and hottest thermites to make in his opinion and experience was equal amounts steel+copper+aluminum powder, and that it burns extemely hot, anyone have any experience with this mixture?

Secondly, I have also discovered that with most ignitable mixtures, the smaller the mesh the faster the burn, (this is obviously well known and I don't mean to state the obvious) however I found that a mix of 60% KNO3, 40% White table sugar and a dash of AN, when ground down to a 3500 or so mesh (3600 holes per square inch rough measured size) burns almost instantaniously, with a small whump, reminding me of flash powder, without the same amount of light. Any thoughts?

(Sorry forgot to link the above statement with the question of whether a finer mesh would make thermites burn significantly faster or not always?)

Ps: I am most happy to be able to post here, seeing as I tried posting on E&W for several weeks, and have never had any success, possibly an error with my internet sucurity...*shrugs*

[Edited on 20-11-2004 by Mickhael]

neutrino - 19-11-2004 at 19:30

Quote:

Originally posted by Mickhael
equal amounts steel+copper+aluminum powder

I don't see an oxidizer in this mix. Perhaps it was some oxide of copper? I've heard that thermites with copper oxides are very powerful, although the steel still doesn't make sense.

The_Davster - 19-11-2004 at 19:43

Erm...
Number one is not a thermite, just a flamable(?) mix of powdered metal powders. And the second mix is not a thermite either just modified smoke powder.

I think I have the same problem on roguesci, my posts take a few weeks to appear, so by the time they do they are no longer needed/relavent.

Today I lit a small pile of magnesium pieces, just for kicks, made by drilling a block of magnesium. I was expecting white magnesium oxide to be produced however a black material was produced that floated in the air for a few dozen seconds then settled to the ground. Was this magnesium nitride? The only white product produced was very small and stayed on the block of wood where the magnesium was ignited.
I must say, I love my UV blocking goggles :cool:

. I watched the magnesium burn directly and I did not get those weird "black spots" in my vision after. The only thing that ever left those "blackspots" in my vision when I was wearing thoose goggles is when a tiny piece of plaster incendiary caught 2' from my face while going at it with a blowtorch. It only caught after going at it with the propane torch for 5 min.

BromicAcid - 19-11-2004 at 20:08

As for the mixture of metals look at the thread on Bi-metallic fuse. That covers mixtures of metals that produce very high temperatures without the need for an oxidizer.

boris_73 - 20-11-2004 at 07:19

i have recently tried PbO/Al mixture of metals even though it did burn very fast, it was not what i expected, i heard that it explodes in the open but this did not happen, i have the correct ratios mixed which were 3 moles of PbO and 2 moles of Al and they were a quite fine powder, could somebody tell me if it actualy does explode or is this just a myth,

[Edited on 20-11-2004 by boris_73]

hodges - 20-11-2004 at 14:42

Are you sure it wasn't PbO2 that reacts explosively with Al vs. PbO?

boris_73 - 21-11-2004 at 04:15

i know i was thinking that or it might be Pb3O4

Silicon Dioxide thermite

chemoleo - 2-1-2005 at 21:31

Today this was tried, in stoichiometric proportions, i.e. 54 g Al and 180 g SiO2, according to 3 SiO2 + 2 Al --> 3 Si + 2 Al2O3.
1. SiO2 as in quartz sand, >0.1 mm grains
2. SiO2 as from pottery supplies (fine powder), seemed a little wet though
3. SiO2 as from pottery supplies, fine too, and dry, but purity not known.

Using 400 mesh Al, none of the thermites worked! Not even 5 sparkling candles tied together, or direct ignition with a Bunsen burner, or a NaClO3/Al mixture (which is very bright and hot). None of them.
I am quite baffled by these results, in the light of a method in Jander&Blasius on the preparation of silicone using quartz sand.

Then, I remember using the reaction product from burning silicone (which is SiO2 with impurities), and that did seem to work sluggishly (see above).

I would have assumed that using the pure substrate would yield better results, but this... hmm.

Any ideas? One thing I will do is to 1) precipitate SiO2 from waterglass, dry and 2) dry the existing pottery supplies SiO2, and try again. But I very much feel that this won't work - having made so many thermites to this point, this seems the most reluctant one

S.C. Wack - 2-1-2005 at 21:54

Sulfur. Schlessinger writes of 90 g sand, 100 g Al powder, and 120 g S in a crucible which is in sand. It is ignited with Mg powder and a Mg ribbon.

Henderson and Fernelius use only 90 g S, and ignite with a 1:10 w/w Al/BaO2 "starting mixture", also with Mg fuse. Their compact 1935 book "A Course in Inorganic Preparations" will be appearing soon, I scanned it earlier today.

Um, it should be pointed out that this will of course produce a lot of SO2, and adding acid to break up the sulfide slag will produce H2S.

evilgecko - 5-1-2005 at 23:06

One of the main uses for thermites is too melts things, and that is what I want to do. And I'm thinking the slower the thermite burns the more heat will be transfered to the object. I've made CuO/Al and that burns way too fast, but I'm thinking if I cast it it might slow it down. I heard somewhere (I think it maybe the dreaded Anarchist's cookbook), that you could add plaster of paris to mould thermite. Im going to add 10% plaster of paris to a CuO/Al mix (4:1), wet and pour into a small mould and set. To ignite i'll use S/Al 2:1.

[Edited on 6-1-2005 by evilgecko]

neutrino - 6-1-2005 at 03:21

The amount of heat liberated should only depend on the quantity of thermite and how much heat is liberated per mole of reactants.

Mr. Wizard - 6-1-2005 at 09:33

Strictly speaking neutrino's reply is correct. The heat released is determined by the quantity and type of the reactants, but the rate at which the heat is released does play an important role in it's use, as does the physical properties of the reactants, both during and after the reaction. Iron oxides with Al tend to be slower and have higher melting point components than say Copper Oxide and Aluminum. There is also the difference between heat and temperature which many confuse.

evilgecko - 6-1-2005 at 15:03

I have noticed that if you add more aluminium that neccecary it slows down the reaction, and more heat is directed onto the surface it is on, than if it was fast and most of the heat went into the atmosphere. Maybe this is because the molted iron has time to fall onto the surface and melt it

optimus - 20-1-2005 at 09:04

I have a few chemicals which I don't presently have any use for. Zirconium Oxide, and Cobalt Oxide. Could I make thermite with these?

Are there any uses for Gallium metal other than to look at?

neutrino - 20-1-2005 at 11:20

You could make a thermite from aluminum and the cobalt oxide, but zirconium oxide would be very difficult because the reaction releases little heat and would be hard to get self-sustaining.

As for gallium, you could sell it on eBay and get a decent price or add indium and bismuth to get field’s metal, an eutectic alloy that melts in hot water.

optimus - 21-1-2005 at 07:59

Thanks for the reply

Would anyone care to suggest a ratio for the Cobalt thermite? Would the Zirconium thermite be worth persuing? Would it be possible to convert the oxide to zirconium metal?

Please, forgive my lack of knowledge.

The_Davster - 21-1-2005 at 11:49

Use 2.4g of Al per 10g of CoO. This is the stoichiometric ratio.

optimus - 28-1-2005 at 02:11

Thank you. I shall give it a go.

Quince - 24-2-2005 at 21:40

Thermite/AN Propellant

http://flux.aps.org/meetings/YR01/SHOCK01/abs/S590003.html
Anyone able to access the full text? I was unable to locate it through my university's e-journals access.

Pb3O4 Synthesis

I've read it can be made by adding sodium hydroxide to lead nitrate. Two questions: can I substitute calcium hydroxide for this, and is it reasonable to make lead nitrate from elemental lead (my reagents are very limited: concentrated H2SO4, very weak HNO3, 35% H2O2, NH4NO3). Or is there a better way to make Pb3O4?

[Edited on 25-2-2005 by Quince]

neutrino - 25-2-2005 at 07:38

This looks like a precipitation reaction, which means that you’d need a soluble hydroxide (Na, K…). There was another thread here about dissolving lead for the purpose of making PbO2 electrodes, look in that for advice.

Quince - 25-2-2005 at 20:06

OK, I posted in that thread.

About my other question. I don't know how they get propellant from thermite and AN. Also, I had read somewhere that propellant can be made from 90% AN and 10% polyurethane, but when I tried that it wouldn't ignite from a sparkler (just smoked while the sparkler was heating it)...

[Edited on 26-2-2005 by Quince]

neutrino - 25-2-2005 at 20:11

What exactly do you mean by ‘propellant’? Thermite reactions give off a good deal of heat and keep a large part of it in the metallic product. Ammonium nitrate is an oxidizer. You don’t really get anything by mixing a thermite mix and AN.

Quince - 25-2-2005 at 22:03

Well, did you look at the link? Here it is again:
http://flux.aps.org/meetings/YR01/SHOCK01/abs/S590003.html

neutrino - 1-3-2005 at 05:21

Ah, there was also polyurethane in there as a fuel. My guess would then be that the AN + PU = propellant, the thermite is just there to increase the temperature and thus the pressure. I wonder how it performs?

Mr. Wizard - 1-3-2005 at 10:00

I don't see why using Calcium Hydroxide with Lead Nitrate wouldn't yield a precipitate. You start with a soluble Lead salt and a slightly soluble Calcium salt and you end up with an insoluble Lead precipitate and a soluble Calcium salt Ca (NO3)2. It may take a little time for this to react, as the hydroxide ( CaO actually) won't all dissolve immediately. Keep contact with air to a minimum while it is sitting, as the Calcium hydroxide will pull CO2 out of the air and form CaCO3 (chalk) and precipitate. It looks interesting. You will even be able to recycle the nitrate.
BTW my old 1958 chemistry set book always used CaO (lime) dissolved with Na2CO3 (washing soda) as a source of Sodium Hydroxide. The precipitate was CaCO3 (limestone).

haydz - 8-3-2005 at 20:50

how fine does the aluminum have to be in a thermite Al/Fe203 mix?
is it possible to use bits of aluminum cut up by scissors? theyre still pretty small

Quince - 9-3-2005 at 23:43

Mine were smaller and it still didn't work.

I finally found Al powder (they call it aluminum bronzing powder) in a paint supply store. Try Google's Local Search, and type in paint supply.

Magnesium iron thermite video

12AX7 - 11-4-2005 at 10:28

Oh yeah, just remembered I had this on hand...might as well post it here.

http://www.abymc.com/Video/Thermite.avi 2.1MB DivX.

That was uh....70 grams?

Tim

12AX7 - 11-5-2005 at 12:43

Cu2O + MgAl
http://www.abymc.com/Video/CuThermite.avi

Burn rate seems pretty normal. I'll note I used 3:1, not 7:1 that just doesn't look right.

Not shock sensitive, as near as I can tell.

Tim

chemoleo - 11-5-2005 at 16:48

Cu2O or CuO?

If it is Cu2O, then the ration of Cu2O vs Al is nearly 8 to 1 if stoichiometry is maintained.

I tried this once (see above), and got a nice regulus of Cu from it.

12AX7 - 22-5-2005 at 12:22

Burned a packet of about 5g CuO + MgAl today - it didn't explode (suprising, as it burns so very hot in an open pile!), but it did burn jetwise with a nice volume of smoke and one joyful side-effect - all the material in the path of the flame was metallized, both mineral and organic coated with a dark pink layer. I'm thinking someone like Cyrus would like to know this..

Tim

IPN - 30-5-2005 at 08:01

Tested few Mg thermite mixes few days ago as I finally got some Al and Mg powders.

http://koti.mbnet.fi/otto2000/Mg_Pb3O4_8g_210505.MOV
http://koti.mbnet.fi/otto2000/Mg_S_2g_210505.MOV

Also tested 3g Mg/PbO2, which was more powerful than the Mg/Pb3O4.

Btw. Zn/oxide mixes seem to create quite fine metal powders that are easy to purify (ZnO dissolves very nicely in acetic acid as chemoleo mentioned, and you get Zn-acetate which can be used to make for example Pb-acetate). I have made lots of Sb and Mn powders that way. Vanadium powder is quite nice too.

Here's also the file about the properties of different thermite mixtures (I think this is the one) if someone doesn't have it. It's quite interesting.

Misanthropy - 2-6-2005 at 23:53

Quote:

Originally posted by Boob Raider
(I miss those days when I could buy kilos of hexamine as camp fuel)

It's still available in 10lb buckets.

picky

uber luminal - 3-6-2005 at 01:24

why does everyone call it thermite? I recall the spelling is just Thermit? (for the trade name) otherwise there is no such name as thermite.

cumbustion - 10-8-2005 at 07:09

Would Al foil ground up in a coffee grinder be fine enough for thermite?

neutrino - 10-8-2005 at 07:47

Yes.

Mr. Wizard - 10-8-2005 at 07:57

Quote:

Originally posted by cumbustion
Would Al foil ground up in a coffee grinder be fine enough for thermite?

Strictly speaking ,yes. Quite large particles will work, but they become increasingly more difficult to ignite. When your materials get to the size of rice grains you need an acetylene torch (or an equivalent) to make a molten pool of reacting components, then the reaction will proceed in a slow manner if the material can fall into the molten reaction zone. This is a good thing if you are trying to form a casting or get a large piece of metal. The finely ground material is easier to ignite, reacts more quickly, and has less time for the waste slag and metal to separate. A good analogy would be burning charcoal. A large chunk will ignite with sufficient heat, burn slowly and do safe, useful work. A fine powder, mixed with oxidizers, will burn quickly, and does a different sort of work.
A mistake I made was to use such small quantities of slow reacting thermite that I didn't get results. Using a 5cc pile didn't work with the material I was using, but making a 200 cc pile and starting with a torch achieved a very strong , but slow reaction.
I would try to keep both component's particle sizes about equal.

halogen - 9-12-2005 at 10:21

Osmium tetraoxide/aluminum thermite. Is that possible?

12AX7 - 9-12-2005 at 14:09

Liquid right? Or at least low melting point. It would probably react on contact.

Which reminds me, how about Mn2O7?

Tim

neutrino - 10-12-2005 at 05:30

I doubt it would work. OsO4 has a very low boiling point (130*C), so it would boil off before it could react. Imagine Al/H2O thermite...

[Edited on 10-12-2005 by neutrino]

PHILOU Zrealone - 14-12-2005 at 02:51

To me everything is possible...everything depends on the speed of reaction...remember that the highly volatile halocarbons do stil react explosively with Al powder or with alkaline metals (initiation by shok or heat)...

So the fact OsO4 is a volatile compound wouldn't be a sufficient reason to say it shouldn't work...

Mn2O7 may on react on contact with Al like it would with any reducer/fuel ...and as Mn2O7 is sensitive explosive by itself...

Mr. Wizard - 14-12-2005 at 10:30

Be aware the oxide of this metal is very toxic, volatile, and expensive.

http://www.chm.bris.ac.uk/motm/oso4/oso4h.htm

I think the 'thermit' reaction might take place under very high pressures, over the melting temperature of Al , as in an explosion. The analogy of H2O and Al thermit was a good one.

[Edited on 14-12-2005 by Mr. Wizard]

chemoleo - 14-12-2005 at 10:56

Yes, it comes at around 120$ per gram, and purchases of more than a gram are highly restricted, due to its potential use as a chemical weapon. Laboratories normally use highly dilute solutions.
http://cns.miis.edu/pubs/week/040413.htm

Now, please, can we go back to somewhat more realistic options? Or are we going to discuss the use of plutonium oxide for thermites, for the next 10 posts?

halogen - 16-12-2005 at 03:22

Now that's an idea...

Wasn't an I2O5 mixture discussed earlier, or was it the roguesci thread?

[Edited on 16-12-2005 by halogen]

PHILOU Zrealone - 16-12-2005 at 15:41

Quote:

Originally posted by Mr. Wizard

I think the 'thermit' reaction might take place under very high pressures, over the melting temperature of Al , as in an explosion. The analogy of H2O and Al thermit was a good one.

[Edited on 14-12-2005 by Mr. Wizard]

Again the only need for the reaction to occure is that the speed of reaction is superior to the heating and boiling of...as a mather of fact...there is a chance Al burns in a vapourised fluid...

I the example I gave Al powder /CCl4 is a detonable mix and CCl4 is volatile fluid...Maybe sore rare combination are even shok sensitive/flame sensitive...
In the case of OsO4 eveything depends on the capacity of OsO4 to give its oxygen and of the heat of reaction..Delta Gr and Delta Hr...

Quote:

Originally posted by halogen
Now that's an idea...

Wasn't an I2O5 mixture discussed earlier, or was it the roguesci thread?

[Edited on 16-12-2005 by halogen]

Despite the strong analogy between the type of reaction:
Oxygen transfer between an oxydiser and a reducing metal...
10 Al(s) + 3 I2O5(s) --> 5 Al2O3(s) + 3 I2(g)
It would no more be a thermite in the proper sense of the term...since I2O5 is a non metal oxyde...

So maybe start a new tread

otherwise this will turn into a mess...were flash compositions will be mixed up with real thermites...

[Edited on 16-12-2005 by PHILOU Zrealone]

kABOOM! - 28-12-2005 at 00:49

I'm ready in the mood to try the CuO/Al in combination with the KMnO4 flash powder in some kind of confinded environment for a reactive target. This should be real fun on the firing range. Will take photo's and high quality video of the event. Stay tuned!

Chris The Great - 28-12-2005 at 18:05

Quote:

Originally posted by chemoleo
Now, please, can we go back to somewhat more realistic options? Or are we going to discuss the use of plutonium oxide for thermites, for the next 10 posts?

Considering the extreme reactivity and flammability of plutonium, I think it would potentially replace Al as the fuel. Pu is a very strong reducing agent....
That is also why plutonium oxide would make a poorer oxygen carrier in thermite.
For unrealistic thermites I would go with gold (III) oxide and Al.

How about peroxide compounds like zinc peroxide? Or maybe copper peroxide (dun't know how to make it) CuO2 which would be substantially more energetic than the CuO mixture.
I think the synthesis might be as simple as H2O2 + Cu(OH)2 -> CuO2 + 2H2O
But I am not sure (that method works to make zinc peroxide).

[Edited on 29-12-2005 by Chris The Great]

kABOOM! - 28-12-2005 at 21:17

...maybe Barium Peroxide/Magnesium --- Aluminum could be a substitue as well... thats a recepy for impact incendary 50 calibre bullets after they got rid of white phosphorus in WWII due to its instability. Just found out about that one...just sharing.

neutrino - 29-12-2005 at 09:45

Would this produce molten barium metal or just a bunch of oxide? If it is the latter, wouldn't this be more accurately classified as a flash powder than a thermite?

kABOOM! - 29-12-2005 at 14:36

Barium Peroxide /Al is certianly an incendary mixture...its not thermite thats for sure. The larger 150mm howitzer shells used a thermite filler with a percussion fuse and combustable core w/ small HE charge for dispersal.

12AX7 - 31-12-2005 at 21:55

BaO(2) + Al > Al2O3 + Ba (unbalanced)

The caveat is the Ba has to be driven off by heat (yellow hot) and sublimated under vacuum. The reaction proceeds due to Al2O3's stability and Ba's (or any other alkaline earth, sans beryllium, for that matter) relatively low boiling point. Not exactly exothermic, though the peroxide will give some initial energy at least.

Ag2O2 would be pretty skookum.

Tim

kABOOM! - 1-1-2006 at 10:01

I'll see what else I can dig up on military tracer/incendary compositions. Heres another: KClO3/Mg/SrCl2 (red tracer)
KClO3/BaCl2/Mg (green chinese/Russian tracer)

crankyperson - 19-1-2006 at 12:38

hellou,
i succesfully prepared chrome and silicium.
chrome is prepared out of Cr2O3 and Al, and silicium out of SiO2 and Al.

I started the reaction with some Mg-powder and a mixture out of KMnO4 and Glycerol..
there are some pics in a german chemnistry forum.if you want to see them,i can put them in....

AngelEyes - 8-2-2006 at 04:33

From NewScientist.com...

Exploding ink
A very unusual ink-jet printer cartridge, containing explosive ink, has been patented by Qinetiq, the commercial spin-off of the British Ministry of Defence.

The ink is a mixture of very fine aluminium particles, each 1 micrometre in diameter, particles of copper oxide 5 micrometres wide, epoxy varnish and alcohol. The ink is stable in liquid form, making it safe to print onto conventional paper, but forms an explosive fuse once dry.

An engineer can easily sketch out a printable fuse using computer imaging software, modifying the delay in milliseconds by changing the length, thickness and pattern of the line on the paper.

The ink can then be printed between a small strip of metal and a larger patch of explosive ink. Feeding a current through the metal strip makes it hot enough to ignite the fuse, which burns until it reaches the explosive patch. This explosion can then trigger the detonation of a much larger amount of explosives.

Qinetiq suggests printed fuses could be used for precisely controlling fireworks, triggering vehicle air bags or for conventional munitions. Ganging hundreds or thousands of fuses together could even make a miniature rocket engine capable of precisely adjusting the orbital position of a spacecraft, the company says.

Read the exploding ink patent in full here. http://tinyurl.com/d6sow

bomberman41688 - 28-2-2006 at 05:49

That sounds very interesting. I'd like to try that.

Quince - 28-2-2006 at 05:50

I don't see how you can DIY powder this fine.

chemoleo - 28-2-2006 at 16:50

Crankyperson, I'd like to hear more details on your reaction with SiO2/Al.
I was never able to do it with this straight mixture, regardless the type of SiO2, even fine dried powder wouldnt do it. I did succeed with sulphur however.

How did you do it without?

Do post the link btw.

Microtek - 3-3-2006 at 11:17

I have used a blender to mill an alcoholic slurry of Al foil. The resulting dispersion of particle sizes were then sorted by various sedimentation and filtering techniques in the wet state. The finest fraction was collected in a filter and examined in an optical microscope and was found to mainly contain particles in the 1-5 micron range.

Endo - 14-3-2006 at 06:18

Quote:

Originally posted by chemoleo
Crankyperson, I'd like to hear more details on your reaction with SiO2/Al.
I was never able to do it with this straight mixture, regardless the type of SiO2, even fine dried powder wouldnt do it. I did succeed with sulphur however.

How did you do it without?

Do post the link btw.

I once reacted ground quartz with magnesium dust in a test tube, On strong heating it started and the exothermic reaction was hot enough to deform my test tube.

One interesting side note is it makes a Silicon-magnesium complex that yeilds Silane gas (Bubbles flash when they hit air) if you dump the end product into HCl.

Not sure if aluminum would do the job...

[Edited on 14-3-2006 by Endo]

Cu/Al BIG TARGET EXPLOSION VIDEO

kABOOM! - 21-4-2006 at 16:42

yep, I'm back at it again. This time I tried to shoot a rather large exploding target using my .223 NATO - Ruger Mini-14. Enjoy the video... PS, it is in MP4 format.

[Edited on 22-4-2006 by kABOOM!]

Attachment: MVI_1431.MP4 (876kB)
This file has been downloaded 1752 times

12AX7 - 21-4-2006 at 18:25

Nice.

Ballpark or exact weight of charge?

Tim

kABOOM! - 21-4-2006 at 21:08

The video shows 1/2 lb of CuO/Al mix...by weight, hard packed into a large plastic ball.

[Edited on 22-4-2006 by kABOOM!]

PHILOU Zrealone - 24-4-2006 at 06:39

Quote:

Originally posted by Microtek
I have used a blender to mill an alcoholic slurry of Al foil. The resulting dispersion of particle sizes were then sorted by various sedimentation and filtering techniques in the wet state. The finest fraction was collected in a filter and examined in an optical microscope and was found to mainly contain particles in the 1-5 micron range.

I dont think the use of an alcohol is a good idea when you get to very fine Al powder ... since a good deal of your Al might react to give alcoholate...unless your Al is somehow passivated by a resistant oxyd layer

Al + 3R-OH --> Al(O-R)3 + 3/2 H2

To my idea better use low bp and unreactive alcanes to allow separation...hexane, heptane, octane...

kABOOM! - 24-4-2006 at 23:22

I guess my next test should be with red lead & Aluminum...tested with a good ol' blast from a rifle. Anyone here made such a mixture? I'm guessing a similar mix was used in rail car crackers, and step on torpedos...right?

PHILOU Zrealone - 25-4-2006 at 08:30

Be careful because PbO2 is a powerful oxydiser and...PB is easily molten and its boiling point is arround 1750°C so gaseous hot Pb might result...

Mr. Wizard - 25-4-2006 at 08:59

Railroad 'torpedos' used in the US to warn RR engineers of problems ahead were not made with lead or aluminum in recent years. I can't be sure they never were, but the ones I have seen were a red paper square 2.5 cm on a side and about .75 cm thick were made with KClO4 sulfur and some sort of sugar or carbohydrate. The older ones had a lead strap on the to attach to the rails, the newer ones had a thin steel spring, with glass reflecting beads on them. They would soften up when moistened with acetone and you could smell SO2 when you popped a small piece.

Microtek - 6-5-2006 at 03:19

I'm aware of the oxide film on my Al powder, but I can't use alkanes as they would most probably attack the blender ( which is a cheap one made of plastic ).

DeAdFX - 6-5-2006 at 19:51

While this post has jack shit to do with Thermite I thought I would contribute this tid bit.

Comments on "Blender Grade Aluminum"
I used denatured alcohol/aluminum foil to make my aluminum powder. A random amount of foil was added into a blender and blended for 5 seconds. I repeated this for awhile until I assumed I had about 100grams of foil in the blender. Enough alcohol was added to the blender to cover the Aluminum foil/powder/whatever the hell. I blended the mix for about 20 or so hours over a 5 day period.

The particles resulting from this mix were fairly large. I would assume 20-100 mesh(calculated by eye). Most in the 50 range. However I did get some really smally floaty shit when I filtered this powder. I didn't burn it but I assumed it was charcoal(fairly dark). I have not seen German dark Aluminum before so I cannot make any good assumptions.

I let the powder dry out for about 1-2 or so hours and then I proceded to burn. The powdered mess burned after heated by the flame of a butane torch for 20 seconds. This was probably because of the alcohol and lack of aluminum oxide.

Summary/Conclusion... Blender grade aluminum is between shit and better than having nothing. I personaly do not believe it is worth 20+ hours of monitored button pushing for some aluminum powder. Having easy access to good quality aluminum powder is obviously a major influence on my conclusion.

Microtek - 9-5-2006 at 23:58

Well, that differs enormously from my results. When blending, it is necessary to use a certain minimum amount of foil/powder and a certain maximum ratio of ethanol/foil. Otherwise the slurry will be too thin to offer the required shear resistance, and will simply be stirred.
The capabilities of your blender is obviously also a factor.
I hypothesize that once the particles have reached a certain size, most of the further size reduction comes from the grinding action of the grains against each other, rather than from the blades themselves.
Once the mix is blended ( about one hour of effective blending time in my experience ) you have a particle size distribution, and if a certain fraction is desired, you need to separate it accordingly. I use a combination of fractional filtration and sedimentation fractioning to get the very fine fractions.
There is only a small amount of the very fine powder ( depending on the amount of grinding of course ) but all of the powder is less than about 50-100 micron in the largest dimension ( and none of it is more than 10 micron in the smallest, since that is the thickness of the foil ).

Quince - 13-5-2006 at 03:21

Instead of making CuO from CuSO4, do this instead: dehydrate by heating some CuSO4, then mix 8 Al with 3 CuSO4. It's even easier to ignite than the thermite.

I got the idea from my Al/H2SO4 experiment (https://sciencemadness.org/talk/viewthread.php?tid=3485&...)
Works great!

At first I thought the main reaction is 8 Al + 3 CuSO4 --> 4 Al2O3 + 3 CuS, but there is some metallic copper left (unlike the Al/Al2SO4 where there is only a tiny amount of metallic aluminum left). So I'm not sure what's going on; maybe the sulfur just burns off.

[Edited on 13-5-2006 by Quince]

12AX7 - 13-5-2006 at 04:02

IME, Al2S3 and MgS are formed. Even with alkalies: Na2SO4 + Mg, uh err, +5Mg = 2Na(g) + MgS + 4MgO. MgS is left as a brown crust (smelling of H2S) in the reaction dish, while Na of course burns off with a bright orange flame.

If you're thinking alternate sodium thread here, it's too energetic. Should make a good yellow/orange flash comp though.

That's a good point about CuSO4 though, it *would* work that much better, moisture aside.

Tim

Quince - 13-5-2006 at 05:38

Where do you get sodium sulfate?

In all my Al+sulfate experiments, I get lots of white Al2O3 powder all over the place; it's the main product of the reactions. I didn't notice but a small amount of yellow Al2S3, and there's only a bit of H2S smell (when I get the residue wet). I also get a good deal of SO2, so it seems much of the sulfur burns away rather than being bound to something else.

[Edited on 13-5-2006 by Quince]

Zinc - 24-5-2006 at 05:33

How about Au2O3/Al (I think this would be very sensitive)?

12AX7 - 24-5-2006 at 05:47

I would think so, too.

Heh, y'think Au2O3 + Mg would be spontaneous? How about Ca?

Tim

Zinc - 26-5-2006 at 11:49

Originally posted by 12AX7

Heh, y'think Au2O3 + Mg would be spontaneous? How about Ca?

Tim

Or how about Au2O3 and Cs?

pyrochem - 2-6-2006 at 16:16

Quote:

Where do you get sodium sulfate?

It is sold as Glauber's Salt, probably in pharmacies. MgSO4 (Epsom salt) would probably also work.

One thing I like to do is take some hydrated MgSO4 and mix it with fine aluminum powder. When heated (indirectly) over a flame, the MgSO4 will fuse and dehydrate to form a solid mass. When this is heated directly or ignited, it flashes with a sort of "pof" noise. It is hard to ignite.

Aluminothermy Synthesis ?

franklyn - 30-6-2006 at 11:51

The use of Aluminothermy chemistry destructively or to make explosions is a
trivial silly use of a very useful method for the reduction of metals such as
Molybdenum, Tungsten and Titanium from their oxides to cast metal parts
without the need for an expensive foundry furnace. The welding and repair of
large broken structural and mechanical parts in the field makes this an invaluable
application.

A very useful excerpt on these techniques first published in 1910 is here
in pdf -> http://www.keepmyfile.com/download/c17666846651

Additionally a mention of the reduction of Plutonium metal using Calcium
described in The Curve of Binding Energy ->
http://img31.imagevenue.com/img.php?image=82480_P_u_31lo.jpg

It had occurred to me that it might be possible to produce by this same method
ceramic materials that are otherwise very difficult to prepare. I am referring to
Silicon Carbide Sic , Silicon Nitride Si3N4 , Boron Nitride BN, and Boron Carbide
B4C
Of interest is the possible formation of new ceramics made of these in chemical
combination. For example, a related engineered material the machinable ceramic
SiAlON is a reacted mixture of SiN, SiO2, Al2O3 and AlN. See ->
http://www.blackwell-synergy.com/doi/abs/10.1111/j.1551-2916...
A special Glock automatic pistol has a barrel and slide made of this which
enables it to get by metal detectors.

I propose that the Flourides of Boron BF3 and Silicon SiF4 reacted with Sodium
metal and some Cyanide or Cyanogen salt may produce new and useful ceramics.
Two possible mixtures _

6Na + KCN + BF3 + SiF4 -> KF + 6NaF + BN + SiC

20Na + 2KCN + CaNCN + 4BF3 + 3SiF4 -> 2KF + CaF + 4BN + 3SiC

Sodium is chosen because It's Flouride salts have a low melting point, less than
~ 1000° C assuring a fluid quick precipitation of the desired product and the
formation of a water soluble slag. The possible products will depend on what
bonding can result. Boron Carbide for example does not exhibit the expected
stoichiometry forming instead as B4C. There are three basic known molecular
species of the reactants , BN , SiC and Si3N4, if this last is produced then by
default , B4C3 would remain. This is not a known compound , which suggest a
new unknown chemistry.

The production of composite ceramic materials from powders invariably results
in a porous product. Pure solid cast samples of ceramic composites may result
employing a thermite process.

.

Zinc - 13-7-2006 at 07:52

How about PbI2/Al?

[Edited on 13-7-2006 by Zinc]

FullMetalJacket - 14-8-2006 at 16:27

From memory, alfoil has a layer of polyethylene over it. I'm probably wrong, though.

Quince - 14-8-2006 at 19:18

If it is, wipe it with boiling xylene; that will dissolve a polyethylene coating.

not_important - 14-8-2006 at 23:58

I don't think 'kitchen' aluminium foil is coated, if it was so the its use to cover dishes being cooked in an oven would have hot polythene fuming all over. Even the decorative coloured foils are anodization and dyes, not a coating per say. Packaging is often multiple layers including aluminium and plastics, and some construction foil is too.

franklyn - while I'll agrre with the start of you message, I don't think that the proposal for complex ceramics is going to fly. Both BF3 and SF4 are gases at STP, making it difficult to get enough of them into the reaction vessel; they also are rather reactive. Also, sodium has a rather low boiling point, not the best thing for these sorts of reactions. Use aluminium and you're likely to get AlB12.

Regarding your comment that Goldschmidt produced ceramics would be solid castings seems to be based on some incorrect assumptions. Silicon carbide decomposes as it 'melts', for example. The contraction of a uniform block of melted ceramic would likely be undergoing rather severe stress, resulting in the formation of internal cracks.

The currently used pressed-powder technologies allow much better control of the phases in the material, domain growth, and so on, than simple melt methods. This is because the temperature and pressure can be independently controlled and not need be monotonic; either or both can be 'cycled' during fabrication of the part. In some cases high pressure is needed to get a desired form/phase of a component in the material.

As for B4C3, I suspect that if it can exist at STP it is known, check out carboranes.

not_important - 15-8-2006 at 07:56

If you want a simple yet exotic thermite-type reaction, try this:

Quote:

In 1904 K. A. Ktihne (D.R.P. 147,87.1) described a process in which external heating is not necessary, a mixture of aluminium turnings, sulphur and boric acid being ignited by a hot iron rod, the resulting aluminium sulphide, formed as a by-product, being decomposed by water.

At the time what was thought to be formed was crystalline boron, most likely it is actually AlB12 or mixture of aluminium borides. It can appears as transparent, near colourless. very hard crystals of high refractive index (pure boron is a very deep reddish, looking almost black in all but the thin layers)

Zinc - 2-10-2006 at 08:29

Today I and my friend made some MnO2/Mg thermite. We ignited it with a small amount of a mixture of KMnO4 and Al. It burned very fast and bright.

Mr. Wizard - 2-10-2006 at 12:07

Quote:

Originally posted by Zinc
Today I and my friend made some MnO2/Mg thermite. We ignited it with a small amount of a mixture of KMnO4 and Al. It burned very fast and bright.

Not ever having tried MnO2 and Mg I can't be sure, but I'd guess it burns easier than KMnO4 and Al. Did it? Some professional thermit mixes are actually started by a Mg mix which is sparked by a Cerium Misch Metal igniter. The mixture actually starts easier from the sparks than from a flame!! The sparks don't seem to have any 'heat' to them, but they obviously have the energy to start the reaction.

Zinc - 4-10-2006 at 06:11

Quote:

Originally posted by Mr. Wizard
Not ever having tried MnO2 and Mg I can't be sure, but I'd guess it burns easier than KMnO4 and Al. Did it?

Yes it did.

The_Davster - 19-11-2006 at 17:57

Kinda Kewl but still amazing.
http://www.youtube.com/watch?v=hNaFWq4JzS8&mode=related&...

I had always wondered about thermite and ice...

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