Sciencemadness Discussion Board

Anyone know what I can do with Manganese(III) Oxide

supertater42 - 12-3-2023 at 20:46


j_sum1 - 12-3-2023 at 20:56

From what source? How pure?

If it is from battery paste then it is a mixture of Mn(III) and Mn(IV) oxides depending on the state of charge. It will also have water and either ZnCl2 or NH4Cl and impurities.
A lot of Mn compounds have a considerable amount of iron as an impurity.

Nevertheless, it can still be a good start point for Mn compounds. MnCl2 or MnSO4 are usually the next stop. Nurdrage's videos on this process are good. His ultimate goal was MnO2 plated electrodes.


In a completely different direction, Mn oxides make for a fun thermite.

supertater42 - 18-3-2023 at 23:56

i tried researching about the chemistry of manganese(III) oxide because i likely dug some out from a battery, but i didn't find much about it like what would it react to for example and maybe finding a way to possibly reducing it to manganese dioxide

i'm also a bit new here.

j_sum1 - 19-3-2023 at 03:34

Purifying battery paste is a good exercise in its own right and one in which you will learn a lot of skills. Nurdrage shows a few methods. I do not know if anyone has made more recent videos, but the procedures will be similar. Fo not be tempted to substitute HCl for H2SO4. You will gas yourself with chlorine.

Don't worry about isolating Mn2O3. Instead convert to a Mn(ii) salt. MnO2 will convert at the same time. You cannot separate the graphite from the oxides without first converting the oxide to something soluble. So not worth trying.

In case you really want the oxide... For most practical uses of tMn(ii) salts they will be oxidised to MnO2 and so you can recover and recycle if you desire.

Be prepared for it to become messy. And difficult to filter.

supertater42 - 19-3-2023 at 15:31

sorry if i sounds a bit dumb but can Mn2O3 react to acids?

DraconicAcid - 19-3-2023 at 15:38

You should be able to reduce it to Mn(II) with acid (hydrochloric or nitric) and hydrogen peroxide), unless it's calcined.

j_sum1 - 19-3-2023 at 16:37

I would be cautious about using nitric or hydrochloric acids -- you will get NO2 or Cl2 gas evolution. No peroxide needed.

I speak from experience here. In my early days as a hobby chemist I managed to fill my shed with chlorine doing exactly this. And it frothed up and overflowed the beaker as well. I had to evacuate in a hurry holding my breath. Breathing Cl2 is not a whole lot of fun.

Edit
Sulfuric acid works fine. The method with oxalic acid is clever and also works well. Follow Nurdrage.
Don't assume that it is MnO3 that you have. It will be a mixture of oxides. And there will be a lot of graphite powder there as well.

[Edited on 20-3-2023 by j_sum1]

DraconicAcid - 19-3-2023 at 16:52

Quote: Originally posted by j_sum1  
I would be cautious about using nitric or hydrochloric acids -- you will get NO2 or Cl2 gas evolution. No peroxide needed.


The peroxide is a useful reducing agent to make sure you don't get chlorine or NO2.

j_sum1 - 19-3-2023 at 17:45

Ok. I normally use peroxide as an oxidiser.
If this works, fine.
My inclination with anything new is to test at small scale first.

woelen - 20-3-2023 at 00:24

Normally, hydrogen peroxide is used as oxidizer, but in this specific case, it is a wonderful reductor. If you have brown stains or a brown mud of hydrous MnO2 and/or hydrous Mn2O3, and you add dilute acid, to which some hydrogen peroxide is added, then you get instant reduction of the manganese(III) and/or manganese(IV) to manganese(II). This reaction is very fast and complete. It only works at low pH though. At high pH, peroxide instantly oxidizes manganese(II) to manganese(IV).

Peroxide also instantly reduces permanganate to manganese(II) at low pH and at (near-)neutral pH, it reduces permanganate to manganese(IV). The manganese(IV) then also acts as a powerful catalyst for decomposition of H2O2.

Fantasma4500 - 22-3-2023 at 06:48

NaOH and a sugar should cause it to turn into MnO or similar lower oxide which shouldnt oxidize acids, then it should be able to react with HCl to make MnCl2
otherwise oxidize it into MnO2 and melt with NaOH for some interesting color chemistry, permanganate