The jersey rebel
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Purification of manganese dioxide.
I have about 5 kilograms of battery paste I want to purify. However I don't want to use more acid than I have to due to age and weight restrictions on
oxalic acid in my home state. I figure that since there is a large amount of carbon that an oxidizer such as KNO3 could be used which I can easily
get. Then you can just wash the resulting carbonates out of the slag. This would strip a good portion of the carbon and also ensure that all the
manganese is in the +4 oxidation state. I don't think that it would oxidize to manganate due to the lack of strong bases. I would like some
suggestions on how to purify it from there or if there are any issues with the viability of my idea.
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blogfast25
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Quote: Originally posted by The jersey rebel  | | I have about 5 kilograms of battery paste I want to purify. However I don't want to use more acid than I have to due to age and weight restrictions on
oxalic acid in my home state. I figure that since there is a large amount of carbon that an oxidizer such as KNO3 could be used which I can easily
get. Then you can just wash the resulting carbonates out of the slag. This would strip a good portion of the carbon and also ensure that all the
manganese is in the +4 oxidation state. I don't think that it would oxidize to manganate due to the lack of strong bases. I would like some
suggestions on how to purify it from there or if there are any issues with the viability of my idea. |
Sounds like a recipe for a mess to me.
Apart from other ingredients besides graphite in the original material, you'll also end up with unreacted saltpetre and maybe left over C (assuming
you can get the C and saltpetre to combine successfully, that is). Nor will it get rid of iron or other metals.
You'd have to have a pretty good idea of how much graphite is in you material, mix it with an extremely fine saltpetre, then fire it for a prolonged
period of time to oxidise the C.
You might s well just fire the material in plenty of air at red heat (w/o saltpetre) to burn of the C and reduce most Mn to Mn(+3). Then purify more.
Whatever you do, at the very least check your post-firing product with strong HCl to detect any residual C.
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The jersey rebel
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Thanks for the feedback. I'll try that on a small scale. Obviously I primarily want to get rid of the carbon since that is the primary impurity.
Although the Iron will simply turn into Fe2O3 and I could use hydrochloric to remove it. Though chlorine gas is definitely not something I'm
interested in producing in a large amount so I'll try to make some sort of scrubber.
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The jersey rebel
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I tried your suggestion and I did manage to strip away a good portion of the carbon out of a 1gram sample. However I don't have a big enough graphite
crucible to try this on a large scale nor could I fit a furnace in my existing set up. For sake of measurement think about the interior of a
minivan . Yeah that's how small my lab is. The reason is simply a matter of
legality. In the state of New Jersey it's not technically illegal to own a lab as long as no neighbors get into the mood to report you. If your lab
takes up a large space or becomes unsightly then people will feel more inclined to report you to the township. So basically it's illegal but it's only
enforced when it becomes a problem or you live in a community that isn't tolerant of this sort of work. I'm soon going to turn 18 so I'll be able to
use my duel citizenship and move to Europe .
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