Sciencemadness Discussion Board

Seperating C and MnO2

cyclonite4 - 26-12-2004 at 06:49

I was wondering if anyone here knows of a way to seperate C and MnO2 from each other.
As most of you know, these two substances are found in batteries. I know that MnO2 is found from ceramics/pottery suppliers, I just like giving different methods a try. ;)

[Edited on 26-12-2004 by cyclonite4]

IPN - 26-12-2004 at 07:30

How about heating in stream of air/oxygen? That should burn the carbon away and oxidise any reduced Mn. :)

BromicAcid - 26-12-2004 at 11:47

You could dissolve the MnO2 in some acid combination then crystalize the salt and re-oxidize. Better yet take a lesson from the processing of ores and try to preform some flotational separation, MnO2 is significantly more dense and a separation in this way may be feasible at home.

kryss - 26-12-2004 at 11:50

I'd go with air roasting tho that might turn your MnO2 into Mn3O4 as welll

IPN - 26-12-2004 at 12:11

Yes, thats true. It starts to change into Mn3O4 at >800C IIRC. That flotational separation sounds interesting though. :)

JohnWW - 26-12-2004 at 13:51

If you want the Mn in solution, and its oxidation state is not important, you could dissolve the MnO2 with a strong acid (which may undergo some oxidation, with formation of Mn(III) and (II) salts; or dissolve it in a strong alkali, which would result in dissolution as manganite(IV).

cyclonite4 - 27-12-2004 at 03:40

Well, manganates would be useful, so i guess i'll just disolve it in NaOH and filter out the carbon.

Does anyone know the solubility of sodium or pottasium manganate in water @ SLC(25degrees C, 101.3kPa)?

BromicAcid - 27-12-2004 at 09:47

Manganates are also unstable, if you dissolved it all and filtered the carbon and unreacted manganese dioxide off quickly your manganate solution would decompose on standing or heating to permanganate and manganese dioxide.

cyclonite4 - 28-12-2004 at 04:45

Quote:
Originally posted by BromicAcid
Manganates are also unstable, if you dissolved it all and filtered the carbon and unreacted manganese dioxide off quickly your manganate solution would decompose on standing or heating to permanganate and manganese dioxide.


That just makes it better, permanganates are very useful on their own. Plus I get some Manganese Dioxide back too, which can be useful too.

Is sodium permanganate similar to pottasium permanganate (in its effectiveness as an oxidiser)?

pbmann123 - 30-3-2005 at 20:19

I was under the impression the the dry cell batery was composed of Manganese Dioxide and Ammonium Chloride and Zinc metal. I have recently bought a second hand centrifuge and was thinking that if you were to calculate the volumetric percent of each and make a suspension with water and then measure and remover the layers according to the volume that they accounted for. when i have some free time i will try this out.

cyclonite4 - 30-3-2005 at 20:39

Yes, you are quite right.

The zinc is the casing, so it's no problem seperating. The ammonium chloride is water soluble, so it can be washed out.

The black powder inside is not a pure MnO2 mix, it consist of carbon. Infact, I think it is mostly carbon.

Good idea. If only I had a centrifuge.
Still... I'll mainly be using the MnO2 for two things, permanganates and as an oxidiser (handy for making chlorine from cheap, readily available HCl).

EDIT: By the way, tell me how the centrifuge goes when you get some free time. :)

[Edited on 31-3-2005 by cyclonite4]

Organikum - 30-3-2005 at 20:45

Quote:

Good idea. If only I had a centrifuge.
Well put. Filtration of finely divided carbon is about as funny as filtration of cyanuric acid after a reaction with TCCA.

[Edited on 31-3-2005 by Organikum]