Permanganates can always be recycled though, which is a big advantage.
(Marvin)
Any practical low budget ideas?
My suggestions:
1)anodic oxidation(takes ages)
2)oxidation with relatively cheap OTC-substances such as weed killer(NaClO3)...i haven´t thought this to the end, i just know this would be one of
the cheapest of the stronger oxidizers...Polverone - 7-3-2003 at 11:34
Yes, #2 should be a good choice. If you want KMnO4 convert it to KClO3 first. The Muspratt encyclopedia has instructions about this method (fusion of
MnO2 with chlorates).BASF - 7-3-2003 at 13:07
Thanks for the hint on Muspratt.....this would be quite a cheap method thenMarvin - 27-3-2003 at 11:09
As Ive posted in the other thread, eventually, The method I like the most is fusion with alkali hydroxide, which air oxidises to manganate(IV),
treatment with acid forces disproportionation to MnO2 and permanganate.
Any oxidising agent in the melt should work to speed things up, and since nitrates form oxides on strong heating/reduction hydroxides arnt a problem.
I think this is a valid form of recycling just using up saltpeter/any acid to get what for me is fairly expensive permanganate. I havnt tried this
myself yet, mainly becuase Ive not used up any of my permanganate.
The process with chlorate doesnt interest me much, becuase the K salt isnt easy to make/get for me, and becuase reduction doesnt form anything that
can form a salt with the manganate(VI) so extra hydroxide must be supplied and in this case means potassium hydroxide which I cant buy here.vulture - 27-3-2003 at 13:17
How about oxidation with persulfate?Marvin - 28-3-2003 at 12:44
Interesting you should suggest this, persulphates arnt thermally stable enough to be used in the alkali fusion method I would think, but I youve
probably read what Ive read, that silver catalysed persulphate will oxidise to permanganate directly. I dont have a method though, I only know it can
be done. The only persulphates I can get here are PCB etchants and contain other rubbish in it, and its expensive, so I havnt tried crystalising it
out.
Making persulphates isnt too diffeicult, but its the large value of the faraday that screws up most preperative electrochemistry at home. On the
subject of which I'm still thinking about 5v@50A from ATX power supplies. This wont work for persulphate though.menchaca - 29-3-2003 at 07:33
I´ve thought in this process:
MnO2+2NaOH+NaClO-->Na2MnO4+NaCl
and later youn can oxide Na2MnO4 to NaMnO4 with sulfuric acid
as alwais im not sure about if this works but...well this is my idea..
