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unionised
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That's nice.
Do you plan to come back later and address what the OP asked for which was
"what I could do for degradate and separate granite components."
The reason I ask is that fairly hot phosphoric acid will actually do that.
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SWIM
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Maybe if you just leave the granite sample here on this thread it will be decomposed by pure orneryness.
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Melgar
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You assumed that, you never actually attempted it or tested it or found a source that did either of those things. Granite is a lot more complex than
silica too, so there's every reason to believe that this doesn't have a chance of working.
I'm not super worried about you derailing the thread, because all the good ways to separate components have already been mentioned, but there is still
one bad suggestion that needs to be put to rest.
I attached the source I posted earlier, which I assume you didn't read. Page 2, third paragraph. I tried to copy and paste it, but the formatting
was messed up due to the PDF.
Attachment: silicAphosphate.pdf (485kB)
This file has been downloaded 289 times
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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DraconicAcid
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Quote: Originally posted by Melgar  |
You assumed that, you never actually attempted it or tested it or found a source that did either of those things. Granite is a lot more complex than
silica too, so there's every reason to believe that this doesn't have a chance of working. |
It might also mean that it will react with the quartz bits and not the other bits.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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unionised
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| Quote: Originally posted by Melgar |
You assumed that, you never actually attempted it or tested it or found a source that did either of those things. Granite is a lot more complex than
silica too, so there's every reason to believe that this doesn't have a chance of working.
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Phosphoric acid attacks silica.
The silica in granite is not "magic" silica that somehow resists attack.
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Melgar
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And phosphoric acid is not some sort of "magic" acid that can dissolve the silica on the inside from the outside. It's also not the same thing as
"fused quartz", which is amorphous. Depending on the silica content of the granite, there's a very good chance of just etching the outside of the
rock a little a bit, leaving the inside untouched. Not to mention, metaphosphate is solid, and the higher its silica content, the less water-soluble
it becomes.
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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unionised
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Thanks for explaining why it's' kind of traditional to grind stuff to powder before seeking to dissolve it.
Incidentally, the data I can find say thing like "The silica content of granite should be at least 70%"
From
http://www.devonmemorials.co.uk/memorialmaterials.html
Which suggests that even bulk granite should be fairly susceptible to dissolution.
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unionised
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I got round to digging out that book + checked the references.
The reaction of silica with phosphoric acid was reported somewhat earlier than the 1990s.
"Sur une combinaison d’acide phosphorique et de silice ; par MM. P. Hautefeuille et J. Margottet"
https://fr.wikisource.org/wiki/Comptes_rendus_de_l%E2%80%99A...
Though it's hard to see why it matters when it was reported; it happens.
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clearly_not_atara
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| Quote: Originally posted by unionised |
That's nice.
Do you plan to come back later and address what the OP asked for which was
"what I could do for degradate and separate granite components."
The reason I ask is that fairly hot phosphoric acid will actually do that. |
Dissolving does that better than anything else. There's no reason to believe that the rxn product of granite with phosphoric acid will be easy to
separate into components, or anything other than a solid concretion, for that matter. None of the references you've linked say anything like this at
all. I looked up dozens of papers on granite analysis; phosphoric acid was never mentioned.
Congratulations, phosphoric acid reacts with silica. Who says it doesn't also react with every other component of granite? It reacts with all of the
metal oxides; you go from a mixture of silicates to a mixture of phosphates. How precisely does converting insoluble silicates to insoluble phosphates
allow you to separate them into components?
Phosphates are insoluble, therefore not useful. Dissolving things allows for differential precipitation, it allows you to actually get something from
the granite; you've diverted this thread into "does silicon phosphate exist?" and you know it. Which is why you have chosen to post yet another
irrelevant paper about the reaction of phosphate with silica instead of a paper about the reaction of anything at all with granite.
Alkaline hydrolysis is still the best actual solution to the actual problem being posed here.
[Edited on 30-10-2017 by clearly_not_atara]
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