[mgolan]

Given highly saturated potassium aluminum hydroxide  KAl(OH)4 in 20-30% KOH solution , the usual way to precipitate  Al(OH)3 is to add an acid.

I'm however looking for a way to do so without effecting the KOH solution, so it can be reused to dissolve more Al.

Any reduction in the saturation of the KAl(OH)4 would be sufficient for me.

Anyone care to speculate on the addition of ozone or other highly oxidizing addition?

Some literature implies that precipitation can be initialized with "seeding" of poweder aluminium hydroxide (hydrargillite), but we couldn't replicate it in the lab.

[Hunter2]

The problem is the solution is to alcaline. Acid is needed. You can try to blow carbondioxide through the solution. The given aluminiumhydroxide will be very clean, because Al dont get a carbonate. After seperation the potassium carbonate can be baked and formed to pottasium oxide, which can be converted back to hydroxide by adding water.