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Specialty Chemistry Forums => Other Sciences Question Forum => Topic started by: Scrystals on May 20, 2004, 01:30:19 PM

Title: aluminum oxide solution?
Post by: Scrystals on May 20, 2004, 01:30:19 PM

I have been trying to find some information on growing crystals at home
without having access to a laboratory. The only information I found was
usually about growing alum crystals or salt and sugar crystals.
Several years ago I was watching a TV show documentation which showed an
inventor who had grown a large Ruby, basically at home in some kind of
a solution. Since I am not a chemist I was always wondering how he was able
to disolve the aluminum oxide, since aluminum oxide is not water soluble.

So my question is, if it is possible to create a saturated (or almost saturated) aluminum oxide solution with some type of acid or if there is any other way to
create an aluminum oxide solution.

I obviously want to use this solution (if this is possible) to grow corundum crystals.

Any information would be helpfull.

Thanx

Title: Re:aluminum oxide solution?
Post by: Donaldson Tan on May 20, 2004, 03:26:20 PM

Aluminium Oxide is amphoteric. It can react with both base & acid.

Al₂O₃ + 2NaOH + 3H₂O -> 2NaAl(OH)₄

Al₂O₃ + 6HCl -> 2AlCl₃ + 3H₂O

Title: Re:aluminum oxide solution?
Post by: AWK on May 21, 2004, 02:14:05 AM

Al₂O₃ + 6HCl -> 2AlCl₃ + 3H₂O  
Dissolution of alumina in acids is not so simple as this reaction. but, anyway, sallts of aluminium can be easily obtained.
I doubt if growing crystals of alumina from water solution is possible at all since Al₃₊ cation "like to be hydrated".
The only well known solvent for alumina is kriolite (Na₃AlF₆) but it works at about 800 C.