# After you have dropped your copper.....



## Paige (May 30, 2007)

After you have dropped your copper out of HCL with aluminum foil, what is the liquid that is left? Aluminum hydroxide or something like that?

Once you bring the ph to 7, what can you do with the liquid?

Paige


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## goldsilverpro (May 30, 2007)

I looked for info on disposal and couldn't find any. I'm not going to tell you to put it down the drain because, with today's green climate, who knows what is or isn't hazardous waste. If all the heavy metals are out, you should have a solution of HCl, aluminum chloride, and aluminum hydroxide. After adjusting to ph 7 with sodium hydroxide, you probably have aluminum chloride, aluminum hydroxide, sodium chloride (table salt), and aluminum oxide. Aluminum hydroxide is an antacid. Aluminum chloride is an antiperspirant used in deodorant. Aluminum oxide, in one form, is a ceramic (alumina). Doesn't sound too hazardous to me.


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## Paige (May 30, 2007)

Thank you.

Paige


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## AuMINIMayhem (May 31, 2007)

aluminum oxide is also extremely flammable in the presence of oxygen and in powdered form (liquid oxy and aluminum oxide = rocket fuel for the space shuttle..) nothing to be concerned about really, just an interesting fact.. you'd really have to make an effort to make rocket fuel, so don't worry about it, I just thought it was an interesting side note.. 

Derek


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## Harold_V (May 31, 2007)

AuMINIMayhem said:


> aluminum oxide is also extremely flammable in the presence of oxygen



I invite you to give more thought to that statement. If I'm not mistaken, aluminum oxide is used for making grinding wheels for ferrous metals. It is not flammable in the least as it has already been through the oxidization process-----otherwise it wouldn't be oxide. I believe what you're talking about is aluminum powder, which must NOT be oxidized. 

That's true even when working with the Thermit welding process. In that case, aluminum powder reacts with iron oxide, which liberates the needed oxygen for the aluminum to burn. 

Harold

edit: spelling error corrected.


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## ChucknC (Jun 1, 2007)

Aluminum Oxide (Alumina) is used in the furnace cement for small foundries, the ceramic honeycomb in catalytic converters and other high temp practices, so it is not flamable. Aluminum powder, now that is a whole nother ballgame.
Ok, so you use aluminum foil to recover copper from solution. Is this spent AR or some other solution? I think I may have missed a post.
Chuck


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