Hi, I'm trying to extract lithium from lithium ion batteries.
I need to separate the manganese sulfate from the other metal sulfates.
Can I use oxone instead of ammonium peroxydisulfate ?
Thanks in advance !woelen - 3-11-2022 at 12:44
I expect that it works, but only at high pH. Oxone is a strongly acidic oxidizer. I would try dissolving the MnSO4 and the lithium salts, then add the
oxone, and finally add a not too concentrated solution of NaOH. MnO2 precipitates in that case.Fery - 3-11-2022 at 21:40
Couldn't persulfate oxidise Mn(II) to permanganate?DraconicAcid - 3-11-2022 at 22:50
If you just want to separate the manganese from the lithium, just make the solution moderately basic and expose to air. Manganese(III) (hydr)oxides
will precipitate nicely. andyloris - 4-11-2022 at 03:27
Thanks ! RU_KLO - 4-11-2022 at 10:22
@DraconicAcid,
most leacheates from Li ion batteries have/could contain.
Mn, Ni, Co and Li.
If solution is made basic and hydroxides are formed by bubbling air, for separating Mn from Li.
How will this affect Co and Ni?
or let me refrase: if bulbling air separates Mn hydro(oxides) only or other (hydr-oxides) are separated as well. ie not pure mn hydro(oxides).
Thanks
Fery - 4-11-2022 at 10:48
Solubility of hydroxides of Mn(II), Ni(II), Co(II) are at range mg per liter and ug or ng in excess of hydroxide.
You can then filter out hydroxides of metals, Mn(OH)2 will further oxidize in air to MnO2.
Finally you can precipitate Li(I) as Li2CO3 by introducing CO2 into the above alkaline filtrate, this compound is less soluble at elevated temperature
than in cold. Eventually further evaporate to squeeze more of the Li (Li2CO3 solubility in water is 6,9 g per 1 liter at 100 C).
If you use NaOH then do not introduce big excess of CO2 as NaHCO3 is also not much soluble (it is less soluble in cold).
[Edited on 4-11-2022 by Fery]DraconicAcid - 4-11-2022 at 10:55
If it's basic enough, nickel, cobalt and manganese will all precipitate nicely.Texium - 4-11-2022 at 11:11
Worth noting though that the hydroxides will be gelatinous and difficult to filter, and the strongly basic solution will destroy filter paper. For
satisfactory filtration, you'll want to use a glass fritted funnel with a layer of filter aid (Celite/diatomaceous earth). Then make sure to clean the
filter immediately with lots of water as soon as you are finished so that it doesn't become clogged.Bedlasky - 5-11-2022 at 02:15
Couldn't persulfate oxidise Mn(II) to permanganate?
Yes, but in acidic solution. I don't know if it works in basic solution. And reaction is really slow, Ag+ is usually use as catalyst and heating is
necessary.
If you just want to separate the manganese from the lithium, just make the solution moderately basic and expose to air. Manganese(III) (hydr)oxides
will precipitate nicely.
Reaction with air is very slow and MnO(OH) is pain to filter, MnO2 is easier to filter.Boffis - 5-11-2022 at 03:05
One further issue to remember when precipitation MnO2 from aqueous solution is that higher Mn oxides have a great ability to co-precipitate alkali and
alkaline earth metals plus lead, thallium, silver etc. and this includes lithium so going down the route you propose you may loose much of the lithium
to the precipitate.Diachrynic - 5-11-2022 at 05:51
I expect that it works, but only at high pH. Oxone is a strongly acidic oxidizer. I would try dissolving the MnSO4 and the lithium salts, then add the
oxone, and finally add a not too concentrated solution of NaOH. MnO2 precipitates in that case.
woelen is spot on. I recently made MnO2 this way, using the commercial triple salt 2 KHSO5 · KHSO4 ·
K2SO4 and MnSO4. Without added NaOH the solution just took on a reddish color (maybe some Mn(III) going on?), but as
soon as I added NaOH it all precipitated quite nicely. It was difficult to filter, with gravity or with vacuum. The filtrate had a green color (maybe
Mn(VI)?) but it wasn't stable for long, and no permanganate color was seen on reacidifying the filtrate. Adjusting the pH of the
MnO2-suspension with dilute acetic acid only mildly improved the filtration speed.
So be warned, it is messy.
As a tip, solutions of vitamin c have served me nicely in cleaning up these 'fresh' manganese(IV) oxide stains.
[Edited on 5-11-2022 by Diachrynic]Bedlasky - 5-11-2022 at 17:10
The filtrate had a green color (maybe Mn(VI)?) but it wasn't stable for long, and no permanganate color was seen on reacidifying the filtrate.[Edited
on 5-11-2022 by Diachrynic]
