Author Topic: Manganese salts from batteries  (Read 1565 times)

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ning

  • Guest
Manganese salts from batteries
« on: May 20, 2004, 07:14:00 AM »
Stupid chem question here, but the net's not helping.

What is the oxidizing power of Aqua Regia compared to MnO2?

More specifically, I'm wondering what would happen if the mixture of MnO2 and Mn3O4 found in batteries were subjected to aqua regia treatment. What salt and oxidation number would I end up with? It seems to be such a waste to blast KMnO4 down to an Mn(II) salt, only to oxidize it back up again to Mn(III). Old batteries contain an electrolyte, carbon, and manganese salts, whose oxidation level depends on the charge state of the battery. To use this as the raw material for Mn(OAc)3 synthesis would bee most honorably economical and efficient.


Osmium

  • Guest
With an excess of aqua regia you should be...
« Reply #1 on: May 21, 2004, 11:11:00 AM »
With an excess of aqua regia you should be able to reach the highest oxidation state. The problem is that you will produce shitloads of Cl2 gas this way. I'm not sure what type of compound you will produce, if you boil off the HNO3 you will most likely end up with some MnO2 sort of black rock.


ning

  • Guest
I want a low salt
« Reply #2 on: May 23, 2004, 07:15:00 AM »
So this would produce from a mixture of manganese oxides in various oxidation states uniformly MnCl2, for example? Or  MnCl4? Which could bee reacted per the Mo(OAc)3 doc with KMnO4 to give the desired acetate?

It's just that the damn oxides are so insoluble....

Chlorine's no big, we have uses for that.


bio

  • Guest
Mn3
« Reply #3 on: June 02, 2004, 03:21:00 AM »
I have done this and it works. Trying to find the patent number but need to get to my other computer. If you will really do this pm me for more.

Oxidize the MnO2 in acetic acid (enough to allow stirring about 70deg helps but any temp works) on a carbon anode spaced 32mm or so from a SS or carbon cathode. A battery bag as membrane helps yield (ca.10-20% more) but an undivided cell works OK. When calculated Faradays (plus about 40%) are passed, filter, (not essential) add more acetic acid then decrease current density from about 80mA/Cm2 to 35, pass the correct moles of electrons (plus ca. 40% depending on your current efficiency) and walla Mn3 Acetate. This can also be done insitu with the Bz and Me2CO and also to regenerate the Mn3 insitu. It's all in the patent which I found right here on the Hive (thanks Rhodium).

 I did find it works better to dissolve the MnO2 in conc. HCl first as the chloride is very soluble whereas the oxide gives an awful muck. Have fun and good luck.