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 Post subject: Alumina for refractory
PostPosted: Wed Nov 10, 2010 8:48 pm 
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Hi everybody:

I'm fairly new here, so this question may have already been addressed. If that is the case please bear with me.

My question is; When you attempt to melt soda cans they oxidise. Could you do this intentionally to obtain a crude form of alumina for a homemade refractory ? I realise that this is probably a foolish idea, yet the thought intrigues me..


Thanks for reading this post.....................mocklane


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PostPosted: Wed Nov 10, 2010 9:30 pm 
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Location: NW Indiana. Close to Lake Michigan S. tip
A home made refractory is sand added to fireplace clay based mortar. It is good for filling in between regular fire brick to build a circular pit for a crucible.

I would not even try that. I save my cans @ .45 lb and buy whatever metal or supplies I need for foundry. The cans burn up if not pushed under a bath right away.

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PostPosted: Wed Nov 10, 2010 11:29 pm 
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Location: Onalaska, WA USA
steamin10 wrote:
The cans burn up if not pushed under a bath right away.

That would be his objective, but I'm of the opinion that the temperature involved to convert aluminum to anything that would serve his purpose is likely beyond that which the home shop can achieve without a considerable amount of effort.

He does present an interesting concept. I know that the dross from aluminum is heated to convert back to elemental aluminum--but the temperature involved is extreme. I expect an arc furnace would be required in either case, which is the method employed by the big boys.

Harold

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PostPosted: Thu Nov 11, 2010 12:03 am 
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Yep, really an electrolytic process, under a flux that takes a long soak time under electric arc. (saw it on the science channel).

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PostPosted: Wed Dec 15, 2010 10:44 am 
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Location: Nova Scotia
mocklane wrote:
Hi everybody:

I'm fairly new here, so this question may have already been addressed. If that is the case please bear with me.

My question is; When you attempt to melt soda cans they oxidise. Could you do this intentionally to obtain a crude form of alumina for a homemade refractory ? I realise that this is probably a foolish idea, yet the thought intrigues me..


Thanks for reading this post.....................mocklane



You can... If by that you mean can you salvage the Al2O3. If the dross is wrung out so it is mainly oxides you can soak it in a acidic solution to remove the remaining Al, a blast of ammonia will drop any acidified Al out of solution as it's hydroxide.

Once that's done the whole mixture has to be boiled and crushed and boiled again to remove salts.

After that's done the mixture needs to be heated to remove all chemically bound water

Once that's done it needs to be ground down to a reasonable particle size.

I did two test batches and decided that in the time it took me to make about 10 grams of impure alumina I could have made enough money working at a fast food job to purchase 10 pounds. I never worked out the cost for the acids and bases or the water because that would have been depressing...


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PostPosted: Wed Dec 15, 2010 11:31 am 
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In my area, the DEA would want to know what I was cooking.

I have been visited before.

They know me now, but still very unnerving.

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PostPosted: Wed Dec 15, 2010 11:57 am 
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It seems that heating anything other then soup gets you a visit from the DEA.


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