DrP - 25-6-2007 at 02:24
Does anyone know how to get vermiculite to solution (aqueous or organic)? Maybe hot alkali? I searched arround and couldn't find anything regarding
disolving the stuff.
Sodium Silicate takes hot alkali, so I'm thinking it might be the same for vermiculite (Mg/Fe/Al-SiO2)??
thanks.
not_important - 25-6-2007 at 02:58
By solution do you mean similar to dissolving salt ir sugar in water, dissolving brass in nitric acid, or just causing it to break down?
Its average composition is given as
(Na0.21,K0.39,Mg0.19,Ca0.13,6H2O)(Mg5,Fe(+II)0.2,Fe(+III)0.8) [Si5.5,Al2.5,O20] (OH)4
It has a fairly complex structure, not atypical for mixed silicates.
If you're meaning is the first, get it into solution in such a way it can be recovered, the answer is no way.
Even if you mean dissolve in the second way, a destructive process that breaks it up and gets it all into solution, that's still not easy.
Alkali won't dissolve the Ca and Mg, nor the Fe except if very concentrate solutions are used, the Al is similar but a bit easier to get into
solution.
Strong acids won't bother the SiO2 content, HF will leave most of the Ca and Mg as insoluble fluorides.
Fused bisulfate is the best solvent, although the silica will drop out if water is added to the cooled melt.
In general, dissolving rocks isn't easy or useful except for analytical purposes.
[Edited on 25-6-2007 by not_important]
DrP - 25-6-2007 at 05:18
Thanks, that helps alot. I'll probably be best with some kind of suspension of fine powder rather than a solution then. There is a company I found
that provides a vermiculite dipersion in water. Unfortunately they are based in the US and don't seem to have any contacts in Europe.
I may try to grind some down and disperse it.
[Edited on by DrP]
Xenoid - 25-6-2007 at 12:04
So you don't want a solution, you want a suspension!
Vermiculite is an expanded mica, and is very soft and pliable, it won't grind in something like a mortar and pestle.
I would suggest putting dry vermiculite in a coffee grinder or blender, something that has more of a chopping action and then mixing the resulting
powder with water.
Xenoid
Eclectic - 25-6-2007 at 12:13
You can just suspend it in water and stir it vigorously after 24 hours of soaking up water. It breaks up with no problem. The problem is if you
DON'T want it to break up if it's very wet. Gardening and farm supply stores have very fine material for starting seeds.
[Edited on 6-25-2007 by Eclectic]