FeroAluminum Thermite

[d22k]

Ok, so i plan to be makin some of this tonight ( ), i was all set to go, when i read something conflicting...

 

previously, i was expecting to mix the chemicals 8:3 (that being 8 grams iron oxide to 3 parts aluminium)

 

and while there have been several variation i have read about, on th whole they are fairly consistent, usualy around 1:3.

 

However, i have now found 2 wources that say the ratio sould be 3:1 ( 3 grams iron oxide to 1 gram aluminium)

 

can someone please clear this up for me?

 

What is the best ratio for the thermite reaction?

 

i am using Fe203 btw, not Fe204.

 

Thanks in advance.

[YT2095]

you want molten iron as your product, so you`ll need to remove those 3 oxygens to make that.

so to make Alu Oxide how much oxygen needs to added per 1 Alu.

 

C`mon, I`m sure you can work this out for youreslf! I hate maths and even I find it simple

 

Thermite is interesting to watch sure, but don`t be afraid to actualy LEARN something in the process, I`ll not give your answer, I`ll HELP YOU to work it out for yourself though

[d22k]

Aluminium Oxide = Al203

so by my reckoning 1:1!?

The maths seems to work, but somehow i dont beleive it

 

also, i assume i would have to err on the side of cation and add a little more aluminium to the mix to ensure a full reduction?

 

thnks

[YT2095]

well you`re bang on the nail there, it is indeed a 1:1

 

however... Al2O3 does not weigh the same as Fe2O3 per cm^3 (or per Mole).

 

so now, with your periodic table handy, calculate how much one mole of alu oxide and 1 mole of ferric oxide will weigh. the difference will be the Alu vs the Iron.

 

there will be your answer

 

 

edit: or even easier, 1 mole of iron and 1 mole of alu, that`ll be the answer too, ignore the Oxygen, it plays no part really.

[d22k]

goes in hunt of periodic table

will report back soon

[d22k]

ok, well i must say, the result is not what i wanted (assuming i did what i was supposed to )

 

the atomic weight of aluminium is ~27 and iron is ~56

 

so that would be 2g of aluminium oxide to 1 gram of iron.

 

not what i wanted, i have 500g of iron and only 200g of aluminium. oh well.

 

pls tell me if i have this the wrong way around btw

 

EDIT:

 

ok, this is killing me now lol, density for iron is 2.5 times that of aluminium so i guess im gonna need MORE than double the aluminium, bah

[YT2095]

2.07gr alu to 1gm Fe.

 

just under 300gr of thermit you can make with it, but what the hell do you want to do with that amount?

 

the only times I ever used that sort of quantity was for sand casting, and the most I ever used in one go was just over a kilo.

 

 

btw, don`t look directly at it!

[d22k]

well i wasnt planning to use it all at once, i was hoping to be able to experiment with all sorts of sues, mostyl using some sort of binder, that would let me mould it into various shapes.

 

guess ill just have to use it sparingly

 

thanks for your help

 

d22k

[YT2095]

anytime, may I suggest using silver sand, and making a well in that and your shape at the botton of that well. they make great paper weights, just keep the design bold and simple a pencils width in any line is the minimum, above that you`ll be ok.

and it has to be in a mound, the stuff reduces in size quite alot, so an excess is needed

 

have fun and STAY SAFE!

[jdurg]

Yes. Make sure that absolutely NOTHING can get into the molten iron while it's still liquid. A drop of water, or even a piece of a leaf, can suddenly cause a little 'burst' which will fling molten iron all over the place.

[budullewraagh]

just a note: when you mix the ferric oxide powder with the aluminum powder, i suggest you add a little acetone or some organic solvent. it will create a suspension so you can swirl your mixture so you have random dispersion of particles. the solvent will evaporate and you'll be left with dry, randomly dispersed particles, which ensure a better yield

[d22k]

thanks for the tip budllewraagh

 

and thanks again yt2095 :0

 

jdurg: i have taken precautions, i read that thermite will actually break down water back to H & 0, BOOM

 

So yah, ill be careful.

 

Tonite was a bit of a failiure though, with no magnesium ribbon, and no sparklers (i have some potty permanganate ang glycerine on order tho ) i tried magnesium shavings, just didnt get the job done im afraid, i was only using a small amount, as a test, bout 5 grams in total.

 

oh well, will try again tomorro nite armed with sparklers and a larger measure of thermite, gonna try to mix it with aryldite and cram it in a lock (not for criminal persuits, more proof of concept, something ive always wanted to try ) you can make solid fuel motors with aluminium powder and aryldite, so i dont think that it will heed the reaction too much, i hope, remains to bee seen i guess...

 

 

but thats what this is all about, suck it and see as they say

 

thanks again for all your help.

 

Oh, and i think ive found a new home on these forums \o/

 

laters all

[budullewraagh]

thermites arent easy at all. how fine are your powders? they have to be really finely divided and intimitely mixed. then you need to have the activation energy, which isn't easy either. i'll second jdurg; you want to be careful

[d22k]

hmm, well the aluminium is 350mesh

not sure about the iron, very fine though....

 

what i had done to mix them was stick them in a large container, (only filled about 5%)

 

then shake, shake not vibrate, so i dont theink the iron will have settled......

 

ill get back to you with the results of test two tomorrow night.

 

 

what do u think of the chances with the aryldite?

 

and will nail polish remover do for acetone? (its water, acetone and bitrex)

 

i will have trouble sourcing pure acetone...

 

Alcohol i can do, surgical alcohol...

 

thanks

James

[jdurg]

Also, whatever you are using the plug the hole at the bottom of the reaction chamber, make sure that it's boiling point is FAR above the reaction temperature of the thermite. A very bad thing is when the thermite gets going and your metal plug actually boils from the heat sending the molten iron all over the place.

 

I also want to give you some major points of respect for how thoroughly you're thinking this out and doing your research before going through with the thermite. Far too often on these internet chemistry boards you get the idiots who come in saying 'THERMITE TOTALLY ROCKS! HOW DO I MAKE IT? I WANT TO MAKE A TON OF IT AND WATCH IT GO BOOM! THAT WOULD SO KICK BUTT!'. It's a nice change to see someone come here who has done their research already.

[budullewraagh]

yeah, i've decided to just ignore all those kids who go "OMG KNO3 PWNZ0RZ!"

 

be careful, buddy. have fun too

[d22k]

Update:

 

WOW!

Holy crap! ifter two more attempts this evening i got a working mixture, and wow, i was so impressed, that was alot of fun

 

BUT i have an important point to raise;

The chemisty would dictate that for the optimum reaction the desired ratio would be 1:2.07 Iron to aluminium.

 

With this ratio, although id did burn, it was neither very fierce, nor did it produce much molten iron, it produced a very 'bubbly' slag interspersed with metal 'blobs' (i will post pictures of the results from the three tests if anyone is interested...).

 

So i tried another ratio, with more Iron, as i figured the aluminium didnt have enough iron to react with (an incorrect assumption it would seem, and looking back on it, that seems obvious now )

 

So the secont mix was 7:11 IronOxide to Aluminium. This was more successful than the first, but wasnt great, and produced a slag with bigger 'bubbles' Averaging 7mm instead of the previous 2mm.

 

At this point, i thought, 'What have i got to loose?' and decided to go the other way, so i mixed it up as 8:3 That being 8 parts IronOxide, to 3 parts aluminium.

The results were, needless to say, spectacular, and the reaction was many times brighter and more violent than the prvious attempts, even though i was using about 1/2 the amount of thermite.

 

Can anyone shed any light as to why this is? when all reason would suggest it should have been the other way around....

 

Like i said, if anyone is interestd i will post pics of the resulting 2 piles of slag and 1 wonderful ingot of pure iron

 

Next up, binders! Ive read that sulpher is a suitable binder, but that would involve heating it in the oven, and im not sure that would be a spectacular idea, i dont have access to a lab, so beleive me, this is very much basement science!

 

Still, onwards and upwards!

 

Ill keep updating this thread with my progress, its a good way of collecting my thoughts if nothing else, so even if you dont find this remotely interesting, it serves some useful purpose to me

 

bed time now, be back soon

 

James

[jdurg]

Fantastic! Glad to hear it worked out alright. Sometimes the best science is the stuff you see and do yourself. (Like in my element collection, my chlorine will always have a place in my heart since I generated it, cleaned it, purified it, and dried it on my own. It started as some HCl and Ca(OCl)2). Anyway, as to why the ratios didn't work out as you had expected, it could have been simply due to the intimacy of the mixing. If the iron oxide and aluminum aren't mixed VERY intimately, the reaction won't proceed at the proper rate and the 'impressiveness' won't be there.

 

Still, glad to hear that it worked out alright and that ya didn't get hurt. I bet now you can see why we said to be excrutiatingly careful.

[ffsjoe]

Where can I get aluminium powder apart from united nuclear and other sites like that cos I dont have access to that. Or is its only use pyro?

[d22k]

Jdurg: Yeah, i know what u mean, it was most satifying. How many elements do you have currently?

 

 

Ffsjoe: I got mine off ebay, it cost me £4.99 per 100g (350 mesh) i dont know if thats a good price, but thats what i paid

[jdurg]

ffsjoe: Powdered aluminum can be found in paint shops. I forget what they call it, but it does exist.

 

d22k: In my collection I currently have samples of 82 elements in their 'pure' form. (Pure being >=95%). I have a pure sample of every stable element except for fluorine gas. For fluorine I simply have a bunch of powdered CaF2 in an ampoule. I also have a sample of depleted uranium metal. For hydrogen I have samples of all three isotopes, and for many other elements I have samples of their multiple allotropes. (graphite and diamond for C, Red+White+Black Phosphorus, amorphous and crystalline boron). Pictures of my element collection are displayed over at http://www.chemicalforums.com on their Periodic Table. The entire table can also be downloaded over there from the downloads link or the Links section.

[d22k]

cool, thnx for the link.

 

U got your urianium turnings then?

[YT2095]

Update:

So the secont mix was 7:11 IronOxide to Aluminium. This was more successful than the first' date=' but wasnt great, and produced a slag with bigger 'bubbles' Averaging 7mm instead of the previous 2mm.

 

At this point, i thought, 'What have i got to loose?' and decided to go the other way, so i mixed it up as 8:3 That being 8 parts IronOxide, to 3 parts aluminium.

The results were, needless to say, spectacular, and the reaction was many times brighter and more violent than the prvious attempts, even though i was using about 1/2 the amount of thermite.

[/quote']

 

those results don`t taly up at all!

 

if excess alu was the problem then how come you got a better result that the correct ratio you started with?

secondly when you did the opposite with Fe in excess and it was better again, doesn`t that speak Volumes to you?

 

ie/ there`s some OTHER factor at play here?

[d22k]

well yes, bus i cant think what, i used the same procedure for each test, the only difference was the ratio so i cannot think what the other actor may be...

any ideas?

[Gilded]

Quite odd ratio you got there d22k. I wish I had a dollar (or preferably a euro) everytime someone on the forums gets wacky results from experiments.

 

"Like in my element collection, my chlorine will always have a place in my heart"

 

I certainly hope that if you ever get fluorine it won't literally have a place in your heart.