Making MagnAlium

[Blaf]

Here is your faithful Topic Starter again

So, we all know in general how this compound is made and that it can be easily powdeed in ball-mill and bla, bla, bla....but I would like to know this: If I ever build melting furnace (which I exactly intend to do sometimes in the future) to melt Magnesium and Aluminium, how would I prevent this mixture to burn completely while melting? OK, they say inert gas should be used...but none says which way it should be done. I believe that inert gas (inflammable and heavier than air) should be placed over the surface of the molten alloy...moreover, maybe a constant flow of gas should be provided here...don't know exactly as I couldn't find thorough explanation of this procedure.

Any coments...or God forbid...instructions?

Blaf

[Exhile]

You can simply seal the magnalium with a plate and then melt it, Snipie has managed to make magnalium without inert gas, if you do plan to use inert gas I wouldn't suggest to use CO2, Mg even oxidates under a CO2 atmosphere, use krypton or nitrogen.

[Blaf]

How about Argon? I think this one is available at welding shops too...

Blaf

[Exhile]

Use argon if you can find it, I haven't made MgAl yet (i can buy it) so i have no idea if it will work.

[Duvel]

I've made MgAl a while ago, in the normal air!
It works fine; it makes a crackling sound when thrown in a flame.

One mistake: I've forgotten that the Mg should react with the O in the air, so my MgAl isn't 50:50, but 35:65 I think.

In the future I'll make a mal.

Kevin

[Blaf]

Hello Duvel

Can you tell me what "mal" is? I couldn't get the point, sorry.
So, you've made MagnAlium yourself in open air and nothing bad happened...I've read a few reports on this before and one of the guys supressed alloy & air reaction by tossing some Sulphur over molten mixture which produced Magnesium Sulphate or so which formed protective crust over the top. Now, when you told us it can be done so easily, I'm definitely up to do something myself...

Blaf

p.s. Come again with that "mal" thing, please...

[Duvel]

Good afternoon Blaf..

A mal is a model, mould (sorry for that, it was in Dutch).

And I've read about that too, so the Mg wouldn't react with the O anymore.
I'll try to make a little presentation about making Magnalium.. :wink:

Kevin

[mr.stijntje]

Hi,
I'm planning to make some Magnalium too, to use it in crackling, since I already found all the other ingredients.
But I've got some questions on the melting process.
Aluminium and Magnesium both melt between 600 and 700 degrees centigrade, possible with a charcoal fire, but I didn't manage to heat it up enough to melt Aluminium. Now I was thinking of my mothers clay oven, wich reaches 1100*C, that's pretty much. The oven has its lid on the side, not on top.

But, there are some new problems. At 1100*C you're not opening the oven to throw in some Magnesium, so you have to melt them both at the same time.
That problem solves itself, since there is nearly no oxygen in the oven. So the Magnesium won't oxidize.
(I supposed that was the reason for throwing in the Mg when the Al was molten.)

But the other problem: how will I stirr the mixture when both metals are molten?
If I open the oven, the Mg will start burning, and that's something you don't want in your oven.

I had some solutions for the problem, but I'm not sure if it will work.

First one is completely closing the mould, just leaving one small hole in the mould to prevent it from exploding at those high temperatures. Then you'll be able to stirr the entire mould around, mixing the molten metals.
Second solution is the one I don't really trust, and that is just putting the Al on top, since its more heavy than Mg, and it would sink through it, wich might mix the two metals.
Last one is just leaving it open in the oven just like above, but opening the oven and stirring it with a long piece of metal when both metals are molten.

Anyone here who has some other solutions? Or ideas how I can improve my solutions?

Stijn

[Blaf]

This is not from my own experience but from real life reports from elsewhere on Net so don't take this for granted.
Charcoal alone would not generate enough heat to melt Aluminium etc. It should be pushed a little – I mean additional air supply should be provided. Some sort of blower, air-turbine or so. This would keep the charcoal at its peak temperature and surely melt light metals. This should be done in closed furnace, not on open air. Your mothers clay oven sounds nice but you'll have to take the melting pot out every time you want to stir the mixture. And since the door is positioned sideways, if (I'm not saying it will) the alloy starts to burn, it will be impossible to react immediately. As for melting itself, Aluminium should be completely melted first and then Magnesium goes into mix.

Blaf

[mr.stijntje]

Hello Blaf,
Thanks for your reply, I think the clay oven is not really posible. In a few days I'll be trying to melt aluminium with a propaneburner. (or how-ever you say that)

I'm almost sure it'll work, if it doesn't, I'll try a combination of propane and charcoal.

The blower is also a good idea, I'm sure I've got a Föhn here witch was used to remove paint from things. The Fohn itself already blows air @ 500*C. But the problem is, I don't know where it is.

Gr,
Stijn.

[deadman]

Of course I am very interested, but can only offer what the internet already has to offer. At least this author is generous with pictures and thinks clearly.

http://www.vk2zay.net/article.php/85

I guarantee it makes you want to try it on your own.

[mr.stijntje]

I had already seen that website, but thanks anyways.

I tried it again. With a Butane-burner this time. Still didn't work.
Heated it for about an hour, and the iron on which the can was standing was red to orange. It was really hot!
I isolated it with stones, all around it, and on top. Only two small holes under to let oxygen go in and an other small hole for the gas-tube.

The can itself also doesn't become red, it stays metal-coloured. And the pieces of pressed aluminium foil inside also don't change. So the can doesn't get as hot as where it is standing on.
If the can was red-hot, the aluminium would melt. Almost for sure.

Is it an idea to hang the can above the burner instead of putting it on an iron "don't know the english name for it".
(A piece of iron you use in your barbecue to hang above the charcoal and put your meat on.)

Or does anyone have other ideas?

gr,
Stijn.

[deadman]

The "iron" is referred to as a grill in America, not so sure about in Europe. I never would have thought stories would be called flats.

Have you thought of using a self fed torch. Such as an oxy-acetylen and then having an argon environment. Honestly argon can be bought cheaply at a welding shop. Or if you could find a way to contain it, helium would make a nice reaction free environment.

[mr.stijntje]

Oh, of course, a grill. I think I was sleeping when I wrote it.

Well, to prevent the Mg from burning, I'll just put a lid on. It'll be enough.
And the butane burner I used had enough oxygen. It was a bunsen-burner.
Oxy acetylene is also much more expensive.

Next try will be on charcoal again. With a lot of charcoal, good isolation, and a good blower. I'll have to find the last one first. :)

[Blaf]

Furnace would be best for melting metals. The one I'm deeply fond of has been described in detail at Mr.Lionel's site (http://www.backyardmetalcasting.com) and it's called "2 bucks furnace". It's made of refractory mixture of cement, silica sand, perlite and fireclay...or so. This furnace looks like two flower-pots touching each other with wider sides, has three holes all in all. One on the bottom for metal spills, one on the side for propane burner and one on top as exhaust hole. This little setup seems to be melting Al in 15 minutes time! Check it out, it's worth every second of your time...

Blaf

[deadman]

Blaf, of course you always know how to get to what I've seen. It seams whenever I have a reputable site you mention it or have been to it enough to know it isn't what you want. That is a great site, and makes me want to build one, even without a proper place to use or store it.

Btw, I am living with relatives right now.

I would say making a 50/50 magnalium ingot could take under an hour. The only problem I haven't overseen is how do you mix the magnesium in the molten aluminum?

[Julicher]

If you can get a good enough seal, or you can manage to close it enough, you could shake it. That's how an other guy I know did it. You don't need to shake it too hard.

[Duvel]

Why don't stir it with a long piece of steel?
My MgAl was made in 50 minutes, and (as said) I've stirred it with a piece of metal, the Mg & Al were mixed well.

[mr.stijntje]

And.. Did the Mg catch flame? Or not? I heared that the Mg will burn immediately when it melts...

[deadman]

Magnesium will not burst into flames as soon as it melts. It won't ignite without oxygen present. So usually in a furnace there is very little oxygen, also you don't melt the magnesium at the same time as the aluminum. It is added to molten aluminum then melted.

A steel rod would be resistant to that kind of heat, but what I meant was, that the 2 buck furnace has a covering doesn't it? Maybe I haven't looked at it long enough, but I just didn't see how I could lift the lid and stir without the magnalium bursting from the sudden rush of oxygen. And I really don't want to dump a load of sulfur on my potential magnalium.

[Duvel]

Well , when I did stir the MgAl no flames were created at al..
But, when you stop the heating, or put the melting can away from your heat source, or whatever.. then the whole stuff goes to react. So a lit on the can is a good idea..

But watch it with Sulfur! If you draw some S in the can, a part of it will react with Mg to MgS.
But the other part will react with that little Oxygen in your can to Sulfur(di)oxide (SO_x).
More information about this gas: http://www.cdc.gov/niosh/ipcsneng/neng0074.html

[deadman]

True there are chances of Sulfur Dioxide byproducts with higher temperatures, but like you said the "little" amount of oxygen at that temp is the limiting factor, so there will not be very much produced.I don't see anyone doing this in their garage (I hope) so even the softest breeze will protect you. Good looking out though.

[Dunecat]

Not trying to be a dick here, but we have a whole load of people talking theoretical problems about inert gasses and chemical techniques to stop your MgAl from burning. I will say that unless you are melting many kilos of MgAl, or pouring ingots(for some bizarre reason), any inert gas or use of powdered sulfur to control burning is completely unnecessary. It is as simple as a tin can, with a slightly wider section of tin can to prevent fresh oxygen from getting in. MgAl will form a very very thick layer of oxide on it's surface. Sulfur will make it smell like shit, and argon is plain expensive and hard to contain. Put it in a charcoal chimney or other improvised furnace, and you're away.

Video here : www.youtube.com/watch?v=YML-UiZybmI

Tutorial here : www.pyroguide.com/index.php?title=Magnalium

There will probably be a whole load of crap about sensitivity with nitrates and perchlorates, but I long since couldn't be bothered altering it since I wrote the part on how to smelt it. Unless you plan to make ultra fine MgAl sensitivity problems aren't a big deal, but just keep it dry anyway. Which you should do with all chemicals anyway. MgAl gets to a point where it is too fine and consequently too powerful(for standard fireworks), so don't grind it too much. MgAl is also a great metal powder for flash compositions and thermite. Especially thermite. MgAl's brittle nature means it can be broken up and ground fine in a matter of hours, and depending on how fine the mesh is; can be ignited with fuse. And I haven't bothered with Al powder since :lol: