RogueRose
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Manganese and it's salts - starting point & processes
The forum has a lot of info on Mn and making various salts, but for every example I find of how to do something, there is a conflicting reason for
doing something else, or someone saying that yields are low, there is contamination, low solubility, blah, blah. It's good reading to get an idea of
some ideas but over the 20+ threads (including permagenate threads) there is much conflicting thought.
I've played with MnO2 a little, from old F cell batteries (about 4x volume of D cell's) and it sure was a mess. The MnO2 was SO hard I had to use a
12lb pestel (SS measuring cup filled w/ melted lead w/ rebar stick) to smash it up, but there was still lots of "gravel". I then boiled in a SS pot
(MnO2 seems to attack SS and bond to the surface) and it produced LOTS of froth after about 5+ gallons of boiling water (this was with 3-4lbs MnO2. I
tried adding a little vinegar then baking soda to neutralize, but the bubbles persisted (they were SUPER fine brown particles that stained just about
everything). I'll have to figure out a better way if I want to use batteries again.
I can get MnO2 powder or granules from a pottery shop (Powder is about 25% cheaper...) but would like to figure a way to use batteries since that is
part of the fun!
I also want to purify the MnO2 as best as possible as well as making some KMnO4 7 other salts that would be interesting - so I was thinking that
instead of smashing it up into a powder, I would crush to pieces and put in acid, either HCl or H2SO4. Both are highly soluble in water and can also
be crystalized if I want to have MnCl2 or MnSO4 (why not, right?). Then add some carbonate and make some MnCO3 (after it has been filtered a few
times in the acid solution) which can decomp at about 400-600F into MnO. At this point I would think I would have some pretty pure MnO which should
further oxidize to MnO2 from atmospheric air (correct or do I need something like H2O2?) I'm not sure what would happen if I placed MnO in water, if
it would oxidize and give off heat?
Now that I have some fairly pure MnO2 I can make some pretty pure KMnO4 I would suspect. I could skip a few of the above steps by buying the
carbonate, but at 4.5x the price of the powder MnO2, that is a little steep IMHO and not as fun!
I'm not sure how to make a nitrate as I don't have HNO3 ATM, but do have some salts (will have a distillation setup soon).
MnO2
MnO
MnSO4
MnCl2
MnCO3
I've read that using Cl2 as the acid in the KMnO4 process is a good way to go as it doesn't introduce other contaminates and I could do that but not
sure it is necessary, thoughts on this?
What other Mn salts would be fun to make or good to have around? Are there any other experiments that can be done with any of the above or while
making them?
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PirateDocBrown
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If you are using old batteries, likely a good deal of the MnO2 will have been reduced to Mn2O3.
That's not a bad thing, as Mn2O3 is likely easier to get to convert to a soluble oxidation state. Nevertheless, it would be preferable to have all the
Mn at the same oxidation state, then do the extraction.
I suggest reducing the battery residue, say with sulfite or bisulfite, and seeing if HCl can then get MnCl2 out, from both MnO2 and Mn2O3.
Alternatively, H2SO4 or even NaHSO4 might get you to MnSO4. From there, you could go to carbonate.
I use KMnO4 too much as an oxidizer to be using it as a Mn source. Once it's spent, and sitting at the bottom of the reaction at a lower oxidation
state, I'd consider recovery. Old batteries are essentially free, and have lots of Mn in them.
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RogueRose
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Quote: Originally posted by PirateDocBrown  | If you are using old batteries, likely a good deal of the MnO2 will have been reduced to Mn2O3.
That's not a bad thing, as Mn2O3 is likely easier to get to convert to a soluble oxidation state. Nevertheless, it would be preferable to have all the
Mn at the same oxidation state, then do the extraction.
I suggest reducing the battery residue, say with sulfite or bisulfite, and seeing if HCl can then get MnCl2 out, from both MnO2 and Mn2O3.
Alternatively, H2SO4 or even NaHSO4 might get you to MnSO4. From there, you could go to carbonate.
I use KMnO4 too much as an oxidizer to be using it as a Mn source. Once it's spent, and sitting at the bottom of the reaction at a lower oxidation
state, I'd consider recovery. Old batteries are essentially free, and have lots of Mn in them. |
Thanks for the suggestions! I have a good bit of NaHSO4 so I can give that a try as well as HCl. What would be given off from the MnO2 + HCl? Cl2 I'm
guessing and H2O?
I need to figure out something to do with excess Cl2 and CO2 (and even SO2) for when I'm doing my reactions as I just vent them but I think they could
be used in a much more appropriate manner. I'm not sure if there is any benefit to making CaCO3 out of Ca(OH)2. I guess I could compress it into
some tanks I have (would be nice to have a compressor that does more than 400PSI (my fridge compressor does this) so I can fill my scuba tanks and
than use it later if I find some use for it.
I wonder if using a pressure washer could somehow create a pump that would allow form compressing the gas to a higher pressure. I have a 1800 and
3800 PSI pressure washer that may be of use...
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PirateDocBrown
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I think you could reduce remaining MnO2 (from batteries), then the HCl could get you MnCl2. Don't think you would get Cl2.
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j_sum1
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Battery MnO2 and HCl releases copious amounts of chlorine gas. I speak from experience. It was the first and only time that I needed to evacuate my
lab. And that was working at 20g scale.
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PirateDocBrown
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Yep. That's why you should reduce it first...
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j_sum1
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Easier to add HCl to the MnO2 and manage the chlorine. How were you thinking of reducing the MnO2?
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Perchlorate
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I prefer to just use sulphur dioxide... Bubbling SO2 into a acidified suspension of MnO2, followed by Filtration and then evaporating the mixture down
gets you nearly pure MnSO4 with no side products.
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PirateDocBrown
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That's a way I would go. Once you have the sulfate, it can be made into a wide variety of things.
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NEMO-Chemistry
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Rose you got DE you have cleaned havnt you?
I ask because of the carbon crud in batteries, I ended up using DE (acid washed etc) in a chromatography column,
Then i slowly filtered out the carbon crap after i had the Manganese is solution, its a real bitch to filter sometimes.
For chlorine you could bubble slowly into ice cold Sodium Hydroxide and salt solution to get Hypochlorite (i think).
I am currently making a ultra cold lab freezer.
This is a normal domestic freezer with part of it isolated and the normal thermostat removed. I then put king span insulation inside part of the
freezer. A hole cut in the top of the freezer and into this new compartment, serves as my cooling tin.
I then have a batch of doubled up peltier cells, the cold side goes into the new insulated compartment with a small heat sink, the hot side has a much
bigger heat sink and goes into the normal freezer side. I havnt completed the new one yet, but the small freezer I did got down to around -43C. Cold
enough for liquid Chlorine.
It takes alot of messing around though, a friend on an electronics site, is sure with tweaking this should be able to get down below -80c, but i am
doubtful. The freezer is a UK type, i think these are slightly different inside to the USA ones.
Nurdrage has a video for making pure (ish) battery manganese salts. Might be worth a look?
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woelen
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| Quote: Originally posted by Perchlorate | | I prefer to just use sulphur dioxide... Bubbling SO2 into a acidified suspension of MnO2, followed by Filtration and then evaporating the mixture down
gets you nearly pure MnSO4 with no side products. |
This is not entirely true. For the manganese indeed it is true, you only get manganese(II) ions. For the sulfate it is not true. You get a mix of
sulfate ions and dithionate ions, S2O6(2-). The dithionate anion is not easily oxidized, nor easily reduced. It is a colorless anion. I have some
K2S2O6 and this salt is a fairly dull compound.
Unfortunately, I myself found that MnO2 is hard to find in a decent pure state. When using batteries, it appears to be contaminated with fine carbon,
which is very hard to separate from the MnO2. I also used potteries MnO2, but that stuff contained quite a lot of iron. I dissolved it in moderately
concentrated HCl and added some H2O2 to reduce it completely to Mn(2+). The resulting solution, however, is yellow, instead of very pale pink (nearly
colorless). The yellow color was due to contamination with iron. I have used MnO2 from different sources, but none of the samples was satisfactory.
I had more luck with MnCO3. Good quality (light pink) material sometimes is available from pottery suppliers, and it sometimes also is available on
eBay. You have to be a little lucky though. Sometimes the material is tan colored or even brown. In that case it is contaminated severely with other
compounds (maybe manganese in higher oxidation states, maybe iron).
[Edited on 3-1-18 by woelen]
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NEMO-Chemistry
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| Quote: Originally posted by woelen | | Quote: Originally posted by Perchlorate | | I prefer to just use sulphur dioxide... Bubbling SO2 into a acidified suspension of MnO2, followed by Filtration and then evaporating the mixture down
gets you nearly pure MnSO4 with no side products. |
This is not entirely true. For the manganese indeed it is true, you only get manganese(II) ions. For the sulfate it is not true. You get a mix of
sulfate ions and dithionate ions, S2O6(2-). The dithionate anion is not easily oxidized, nor easily reduced. It is a colorless anion. I have some
K2S2O6 and this salt is a fairly dull compound.
Unfortunately, I myself found that MnO2 is hard to find in a decent pure state. When using batteries, it appears to be contaminated with fine carbon,
which is very hard to separate from the MnO2. I also used potteries MnO2, but that stuff contained quite a lot of iron. I dissolved it in moderately
concentrated HCl and added some H2O2 to reduce it completely to Mn(2+). The resulting solution, however, is yellow, instead of very pale pink (nearly
colorless). The yellow color was due to contamination with iron. I have used MnO2 from different sources, but none of the samples was satisfactory.
I had more luck with MnCO3. Good quality (light pink) material sometimes is available from pottery suppliers, and it sometimes also is available on
eBay. You have to be a little lucky though. Sometimes the material is tan colored or even brown. In that case it is contaminated severely with other
compounds (maybe manganese in higher oxidation states, maybe iron).
[Edited on 3-1-18 by woelen] |
Its Iron Woelen, I have two sources for the carbonate. Bother pottery places
but both very good like pink products.
I got my Cobolt Carbonate from one of them and the Lithium Carbonate from the other, the price i thought was good, that packing is a bit shit though.
Both dont have the Manganese ate the moment, but should in a week or so.
I can U2U the source if you like, i wish i had got some, instead i went with a cheaper source and got.....Iron, ALOT of Iron! In the Uk most Manganese
comes from minerals from just two main sources!!! They supply all the other companies.
The Diatomaceous Earth or ultra fine pumice trick in a chromatography column works well. I have a few small AA size batteries to process, I might try
and grab some pics.
My other source Woelen is a little strange, very rarely i get the chance to buy ALOT of Permanganate extremely cheaply, its cheap enough to erm......
Reduce to pure Mno2
[Edited on 3-1-2018 by NEMO-Chemistry]
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j_sum1
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It is funny comparing countries and availability of chems. I can take a 5 minute drive to the hardware store and find beautiful soft-pink MnSO4 at
high purity. 500g for eleven aussiebucks.
If you calculate that it is economic for me to send some to you (unlikely) then send me a U2U.
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PirateDocBrown
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I am sure I have seen MnSO4 fertilizer around in the US, too. But what else to do with old MnO2/Mn2O3 crud from batteries? Seems a waste to just throw
it away.
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RogueRose
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Wow, Thanks to everyone for all the great info!
For anyone interested in 60watt (or maybe 72watt) Peltier's, I am ordering a bunch of them for about $3 each.
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j_sum1
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If you have 15 minutes or so, Nurdrage has several short clips on getting Mn from battery crud and comparing the different methods.Also some follow up
ones using the product to make electrodes. They really are worth a look.
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Texium
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| Quote: Originally posted by woelen | | Quote: Originally posted by Perchlorate | | I prefer to just use sulphur dioxide... Bubbling SO2 into a acidified suspension of MnO2, followed by Filtration and then evaporating the mixture down
gets you nearly pure MnSO4 with no side products. |
This is not entirely true. For the manganese indeed it is true, you only get manganese(II) ions. For the sulfate it is not true. You get a mix of
sulfate ions and dithionate ions, S2O6(2-). The dithionate anion is not easily oxidized, nor easily reduced. It is a colorless anion. I have some
K2S2O6 and this salt is a fairly dull compound. |
Interesting. I was not aware of that. I recrystallized a
bunch of impure manganese(II) sulfate a couple years ago, which appeared to be contaminated with MnO2 and smelled like SO2.
Because of that, I assumed that it was made using that method. At some point (not likely anytime soon as I don't really have any use for manganese
sulfate) I'll do a gravimetric analysis using barium chloride since it appears barium dithionate is soluble.
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tahallium
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What about electrolysis? Manganese if a reactive metal bit iron afaik will be plated on the cathode right?
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