Sciencemadness Discussion Board

Aragonite

David1Keller - 14-6-2011 at 06:33

Hello,

I recently acquired several rocks containing Aragonite. Aragonite is a specific crystallized form of calcium carbonate (CaCO3) and a close cousin to Calcite. I thought it would be interesting, as an experiment, to try to separate the CaCO3 from the surrounding rock. I will accept all tips on separation, purification, and things to do with calcium carbonate.

Yes, I know CaCO3 is cheap and readily available! Currently this is my only source of CaCO3.


More info on Aragonite:
http://en.wikipedia.org/wiki/Aragonite
http://www.mindat.org/min-307.html





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The WiZard is In - 14-6-2011 at 07:54

Quote: Originally posted by David1Keller  
Hello,

I recently acquired several rocks containing Aragonite. Aragonite is a specific crystallized form of calcium carbonate (CaCO3) and a close cousin to Calcite. I thought it would be interesting, as an experiment, to try to separate the CaCO3 from the surrounding rock. I will accept all tips on separation, purification, and things to do with calcium carbonate.


What is the matrix rock?

Byda - wild marble is not that uncommon.

[Edited on 14-6-2011 by The WiZard is In]

simba - 14-6-2011 at 08:42

When I first saw the topic I read 'argonite' and I thought like... wtf? Argon stones? :P

David1Keller - 15-6-2011 at 11:11

To tell you the truth I have no idea what the surrounding rock is. All I know is that it is a grey crumbly rock. If you look closely you can see the matrix rock in the background of my original picture. I have heard Aragonite forms in metamorphic rocks formed at high pressure and low temperature (glaucophane shists) and in sedimentary environments.

[Edited on 15-6-2011 by David1Keller]

The WiZard is In - 15-6-2011 at 13:03

Quote: Originally posted by David1Keller  
To tell you the truth I have no idea what the surrounding rock is. All I know is that it is a grey crumbly rock. If you look closely you can see the matrix rock in the background of my original picture. I have heard Aragonite forms in metamorphic rocks formed at high pressure and low temperature (glaucophane shists)


The only method that comes upon my mind is gravity
separation. However, it works a lot better if there is a large
difference between the density of your aragonite and the gangue.

Like making bear-stew.... First you have to pulverize your
rock — sieve and separate by particle size. Then put each
sieving into a tall cylinder... run a pipe into the bottom and
flow air or water... water probable is the easier of the two
to regulate. By adjusting the flow the whatever with the
lowest specific gravity will float out first.

For mineral ore processing they use flotation, I have seen it
used in a lead/zink mine in Canada years ago. Problem being
it requires very specif chemicals which are probable easy to
buy in 55-gallon drums but next to impossible to buy by the
kilo. I am not sure flotation would work for on a non-metallic mineral.

Please report upon us back with your results good or ....!

David1Keller - 17-6-2011 at 05:57

I can try that Mr. WiZard. However, I am very busy right now and probably won’t get to it until the weekend.

David1Keller - 20-6-2011 at 13:14

Quote: Originally posted by The WiZard is In  
The only method that comes upon my mind is gravity
separation. However, it works a lot better if there is a large
difference between the density of your aragonite and the gangue.

Like making bear-stew.... First you have to pulverize your
rock — sieve and separate by particle size. Then put each
sieving into a tall cylinder... run a pipe into the bottom and
flow air or water... water probable is the easier of the two
to regulate. By adjusting the flow the whatever with the
lowest specific gravity will float out first.

For mineral ore processing they use flotation, I have seen it
used in a lead/zink mine in Canada years ago. Problem being
it requires very specif chemicals which are probable easy to
buy in 55-gallon drums but next to impossible to buy by the
kilo. I am not sure flotation would work for on a non-metallic mineral.

Please report upon us back with your results good or ....!


I started to crush the rocks, but after I got to .5 cm rock size I realized you could just pick out the CaCO3. I ended up with small chunks of about 95% CaCO3, which is good enough for me!

Madlab - 22-6-2011 at 14:17

Quote: Originally posted by The WiZard is In  
Quote: Originally posted by David1Keller  
Hello,

Aragonite CaCO3 is, right?
If dissolved in carbonic acid (H2CO3), you obtain Ca 2+ (aq) and HCO3 + (aq).
I'm not sure, but I think that through an evaporation you will get a solid CaCO3
If you plan to follow my idea, you better make sure it works before you try out :)