Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: Zerm on November 23, 2010, 10:31:38 PM
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I am looking to prepare finely powdered aluminium through precipitation. I have an idea that I will probably try soon but I would like the forum's input. The procedure I have in mind is the reduction of aluminium chloride with ferric chloride to precipitate aluminium powder and evolve ferrous chloride in solution.
AlCl3 +3FeCl2 -> Al + 3FeCl3
The goal is to make the particles as fine as possible. So for sake of discussion, I ask how would you go about precipitating aluminium? Do you have a better solution or do you think the above procedure will even work? I am going to try the above method for sure and I would like to try anyone else's method as well for comparison. Also, if you have fun experiment ideas for what to do with precipitated aluminum, go ahead and post them here as well.
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I hope you share your results.
I also wonder if you will get aluminum oxide as well
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I am more concerned about hydroxide formation or other effects of Al+3 ion's hydrolysis. I'm hoping the reducing power of FeCl2 will be such that it will inhibit oxide formation. I have never really done any aluminum chemistry so this will be an exciting learning experience. I will certainly let you guys know all the gorey details when I get around to this one.
BTW, I think I mispoke in my original post. Iron(II) compounds are ferrous and iron(III) compounds are ferric. I had these names reversed in that post.
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I am looking to prepare finely powdered aluminium through precipitation. I have an idea that I will probably try soon but I would like the forum's input. The procedure I have in mind is the reduction of aluminium chloride with ferric chloride to precipitate aluminium powder and evolve ferrous chloride in solution.
Since you used the word "precipitate", I suppose you intend to do this in water.
Al is a very reactive element, just like alkali earth metals.
Perhaps if you heated dry FeCl2 with dry AlCl3 at some high temperature ...
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This will not work.
Aluminum chloride is really only stable in water at extremely low pH (it will readily hydrolyze to a hydrous alumina precipitate).
Reduction potentials are all wrong--you're having aluminum oxidize iron? Aluminum trichloride is indeed one heck of a Lewis acid (FeCl3 is strong too).
There's a lot more chemistry going on here; I suggest you review the thermodynamics. I can tell you that you will not get aluminum powder from AlCl3 and any iron compound.