CrossxD
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chemistry of feldspars, silicates, basalt, etc...
How can I extract elements from feldspars?
I know that all tectosilicates are quite resistant and I dont have any hydrofluoric acid....would molten sodium hydroxide work? or is there other OTC
chemical, which etch silicates??
thank you
CrossxD
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diddi
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you really need HF. I have had limited success with most other reagents. AR is slow. Sometimes strong H2O2 added in makes a difference
Beginning construction of periodic table display
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fluorescence
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I don't really know if this is also a feldspar but for the isolation of Beryllium there is also a path using H2SO4 instead of HF. Maybe this could
work with your samples as well ?
http://www.periodensystem-online.de/index.php?id=&el=4
If you look at the white box it's path b).
EDIT:
Sorry the site just went offline after I posted that link...interesting coincidence  and I just saw it's back up again but still missing the content I was referring to. Hope it will return soon but there was a white box in
the middle of the page before with the equations.
[Edited on 26-2-2017 by fluorescence]
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Boffis
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Assuming you don't want to wait geological timescales you have two options; HF as you have already alluded to or flux fusion. The flux can be any
alkali hydroxide, carbonate etc or calcium hydroxide but the later requires higher temperatures and complicates the down stream extraction. For
chemical analysis its not uncommon to use lithium borates too to lower the melting point of the mass. But why would you want to extract anything from
feldspars (there are many feldspars, the name is a group name for M+AlSi3O8 and M2+Al2Si2O8 where M+ is usually Na or K and M2+ is usually Ca) there
are far easier ways to get your hands on these elements. Superheated water turns feldspars into zeolites but this takes a long time under conditions
you are likely to be able to achieve.
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