Sciencemadness Discussion Board

Making Manganese nitrate

CrEaTiVePyroScience - 8-8-2012 at 13:28

Hello,

So , I want to make Manganese nitrate. But since I don't got acces to any manganese compound and haven't found MnO2 in batteries I tried by making it from potassium permanganate.
This was my proces (Just to give you an idea of the scale it was done in a 25ml erlenemeyer):

16 HCl + 2 KMno4 => 2 MnCl2 + 2 KCl + 8 H2O + 5Cl2

The reaction took pretty long and after 24hours there was still sometimes bubbling chlorine gas out but not that often, but I decided to stop the reaction which was almost complete, by filtering it and leaving me behind with the solution and some unreacted KMno4 (only about 10-30%).

Then I wanted to precipitate the Manganese compound by converting it into it's carbonate which isn't soluble in water but since the solution still contained HCl (and it's soluble in dilute acid) I added alot of Sodium Carbonate.

Na2CO3 + MnCl2 => MnCO3 + 2 NaCl
Na2CO3 + HCl => NaHCO3 + NaCl

I first added just enough sodium carbonate so it would just dissolve in the solution without having sodium carbonate precipitating. And was hoping for MnCO3 to precipitate.

But strange enough, no MnCO3 precipated.

Then I added alot of sodium carbonate which didn't all dissolve, filtered it and and washed the residue with alot of water but the residue just dissolved into the water meaning no manganese carbonate was on the residue, just unreacted sodium carbonate)


(Normaly It would've precipitated and I would've dumped the managanese carbonate into HNO3 forming our manganese nitrate , but since that didn't happend im pretty much stuck)

The "synthesis" wasn't found on the internet or from youtube I figured it out by myself , is there anything I could've done wrong? Or does anyone has any advice?


Regards
CPS

[Edited on 8-8-2012 by CrEaTiVePyroScience]

[Edited on 8-8-2012 by CrEaTiVePyroScience]

MR AZIDE - 8-8-2012 at 16:47

Seems strange, that no MnCO3 was precipitated, Maybe you didnt use enough permanganate, and the solubility product of the MnCO3 was not reached as you hadnt created enough Mn(ii) ions from the oxidation of the HCl reaction.

Was there effervescence when you added the excess Na2CO3?.......I suppose there was.

It might be better to add H2O2 to the permanganate solution....this will reduce the Mn7+ in the permanganate to Mn2+ .
The solution will go purple to colorless or very pale pink ddue to Mn2+ froming, with the evolution of oxygen gas, and water.

Adding carbonate to this now colourless solution ,should precipitate the MnCO3.

I think this way is a lot easier to judge, as the color change is easy, no horrible Cl2 gas , and the reaction would be much faster.

I remember wanting to make MnCl2, by precipitating MnCO3 from MnSO4 Ive got. At first the precipitate was a nice pale peachy coloured precipitate as Mn(ii) carbonate should be, , but leaving it standing, while filtering it oxidises its self and went dark brown, which looked like manganese dioxide. I got some of the un-oxidised MnCO3 into dilute Hcl, and evaporated to get a small amount of pale rose pink MnCl2.

Poppy - 8-8-2012 at 17:57

Some types of cast iron are sometimes plntiful of Mn in the order of a few percent (check wiKi for precise relativE). Dissolve off the hell out of the iron and then separate the Mn from the mess

vmelkon - 9-8-2012 at 05:26

Quote: Originally posted by CrEaTiVePyroScience  
Hello,

So , I want to make Manganese nitrate. But since I don't got acces to any manganese compound and haven't found MnO2 in batteries I tried by making it from potassium permanganate.


That seems wasteful. I guess it is easy to buy KMnO4 from your local store.
MnO2 is found in every zinc-carbon battery and alkaline battery (energizer and duracell). People have been throwing away batteries for 100 years.

blogfast25 - 9-8-2012 at 05:46

Quote: Originally posted by vmelkon  
Quote: Originally posted by CrEaTiVePyroScience  
Hello,

So , I want to make Manganese nitrate. But since I don't got acces to any manganese compound and haven't found MnO2 in batteries I tried by making it from potassium permanganate.


That seems wasteful. I guess it is easy to buy KMnO4 from your local store.
MnO2 is found in every zinc-carbon battery and alkaline battery (energizer and duracell). People have been throwing away batteries for 100 years.


Wasteful indeed. If you can't be bothered with batteries, get some MnO2 or MnCO3 from eBay.

Poppy - 9-8-2012 at 08:52

A long term collecting of screws and battery from the street as yet rendered nearly 70 screws and up to 20 batteries! :o
Impressive enough few of them had zinc plates but all should contain MnO2 either in gelatinous or tar or less gelatinous form. Find a suitable solvent for that paste.

Fossil - 9-8-2012 at 11:51

Quote: Originally posted by Poppy  
A long term collecting of screws and battery from the street as yet rendered nearly 70 screws and up to 20 batteries! :o


What?!?

blogfast25 - 9-8-2012 at 12:19

Quote: Originally posted by Poppy  
Find a suitable solvent for that paste.


Or look up one of the many threads on the subject of manganese and battery crud on this forum.

But if you want to waste KMnO4 on this, bear in mind that all excess acid need to neutralised before MnCO3 can start to form: end of effervescence = (more or less) start of precipitation...

[Edited on 9-8-2012 by blogfast25]

tetrahedron - 22-11-2012 at 04:53

i made manganese nitrate from the carbonate + ammonium nitrate (from fertilizer) by this method, which requires no nitric acid. manganese nitrate is very soluble, even more so than ammonium nitrate, which makes recrystallization a pain (i wasn't able to obtain a crystalline product). however, a mix that only contains ammonium nitrate (which decomposes to a gas when heated) as impurity is good enough for MnO2 deposition (e.g. on anodes). i got a fine black MnO2 residue from its decomposition.

Nitro-esteban - 30-8-2013 at 11:08

You can make manganese carbonate by this process:
MnO2 + SO2 = MnSO4.
MnSO4 + Na2CO3 = MnCO3 + Na2SO4.
I have detailed instructions for this on my website: https://sites.google.com/site/dremethylzinc/
The batteries that contain MnO2 are the non alkaline type used in lanterns.

[Edited on 30-8-2013 by Nitro-esteban]

Fantasma4500 - 31-8-2013 at 07:27

MnO2... probably had nightmares about that stuff..

i tried once with NaHSO4 and NaHSO3 mixed in proper amounts
before i knew what the hell it was making SO2, didnt add it to water yet, i assume it was hygroscopic..

i tried also NurdRage's method using conc. H2SO4, oxalic acid and MnO2
no luck

not only is this the most damn messy stuff around of what ive seen, but also is MnO2 very hard to dissolve
i might try with direct SO2 through MnO2 slurry, actually like the whole setup of your site, nitro-esteban, perfectly described..
but im limited to use thiosulfate method for several reasons

blogfast25 - 31-8-2013 at 12:08

Quote: Originally posted by Antiswat  
MnO2... probably had nightmares about that stuff..

i tried once with NaHSO4 and NaHSO3 mixed in proper amounts
before i knew what the hell it was making SO2, didnt add it to water yet, i assume it was hygroscopic..

i tried also NurdRage's method using conc. H2SO4, oxalic acid and MnO2
no luck

not only is this the most damn messy stuff around of what ive seen, but also is MnO2 very hard to dissolve
i might try with direct SO2 through MnO2 slurry, actually like the whole setup of your site, nitro-esteban, perfectly described..
but im limited to use thiosulfate method for several reasons


NaHSO4 + NaHSO3 should dissolve battery crud 'MnO2' in a watery slurry: the process is similar to Nurdrage's SO2 gassing method.

MnO2 oxidises the sulphite to sulphate in acid (and aqueous) conditions:

MnO2 + 4 H+ +2 e- === > Mn2+ + 2 H2O

HSO3- + H2O === > SO42- + 3 H+ + 2 e-

Add up:

MnO2 + H+ + HSO3- === > MnSO4 + H2O (this can be further reworked to NaHSO4 + sulphite, if one so wishes).

This reaction requires water though: add the sulphite (in solution, metabisulphite should work too) gradually to a slurry of battery crud and dilute sulphuric acid or a solution of NaHSO4. This may need a bit of heat to proceed comfortably.

Re. reduction of MnO2 with oxalic acid and sulphuric acid: this does NOT require concentrated sulphuric acid. I've done this successfully with battery crud MnO2, a saturated solution of oxalic acid and diluted sulphuric acid. Mix the battery crud (preferably first cleaned up as per DerAlte's method) with the requisite amount of 30 % (or so) sulphuric acid, then slowly add the oxalic acid solution, bit by bit. As the oxalic acid is oxidised to CO2, strong effervescence occurs, heat is evolved and intermittent cooling may be needed to keep things under control. Post reaction, filter and the filtrate will contain crude MnSO4 (usually contaminated with iron sulphate)

Like all oxides, the degree of ease of dissolution depends a lot on the 'grade'. In the case of MnO2, nearly all grades dissolve easily in strong hydrochloric acid, primarily because the oxide reacts with the acid:

MnO2 + 4 HCl === > MnCl2 + Cl2 + 2H2O, so this produces lots of chlorine!

I think part of your problem is superficial or absent planning of your experiments: like with most things in life but also in chemistry 'failing to plan = planning to fail'...
Quote: Originally posted by Nitro-esteban  
The batteries that contain MnO2 are the non alkaline type used in lanterns.



Yes, but one should never fail to add that they contain MUCH more than that. Firstly, assuming the battery you'll be using is a SPENT one, the manganese dioxide will have been partly or wholly reduced to lower oxides: it's this reduction that drives the EMF of the cell battery.

Secondly, it contains varying amounts of graphite (as a conductor). One professional assay I saw mentioned less than 30 w% of manganese (as Mn) of the battery crud! For comparative purposes: pure MnO2 contains about 63 % Mn.

Other common contaminants are ammonium chloride, Zn chloride or Zn hydroxychlorides and iron oxide. There may also be small amounts of organic binders present.


[Edited on 31-8-2013 by blogfast25]

Fantasma4500 - 20-9-2013 at 09:55

so, would that mean that pure MnO2 is 'shit' for this synthesis, because that might explain why i have failed so many times..

but about the fail with SO2, i weighted out the NaHSO3 and NaHSO4 in a aluminium cup (both dry, hygroscopic i didnt know back then)
when i approached the bottle with SO2 slurry in and water it just went crazy and.. well SO2 suddenly
i guess what might of happened was that it was so hygroscopic, that the water in the air started a reaction

symboom - 7-10-2016 at 05:51

Anyone try ascorbic acid and vinagar
Method im going see if its going to work

That or bisulfate and nitrate salt
The last thing I want is acids and battery crud mess to deal with I think ive had nightmares about MnO2. Dealing toxic gases
MnO2 is already a messy pain a cheap source
But buying manganese sulfate seems nice now

[Edited on 7-10-2016 by symboom]

Amos - 7-10-2016 at 07:02

In-situ sulfur dioxide generation works as a method of dissolving MnO2; just add your manganese dioxide to a boiling solution of sodium bisulfite or metabisulfite. If it's the calcined, pottery-grade stuff, it may need some encouragement from a bit of strong acid. After this you can simply filter and precipitate manganese carbonate with a base of your choice.