[AR] Re: Ion exchange resins for cleaning peroxide
- From: Peter Fairbrother <zenadsl6186@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Mon, 11 Jul 2016 17:51:19 +0100
On 11/07/16 16:36, John Dom wrote:
Peter Fairbrother wrote on 110716:
Strong type 1 cation exchange resins will remove stannates.
I thought stannates are anions and a cation exchanger only removes only cations.
I do have a tendency to get them mixed up; but I checked carefully, both
before and after posting, and this time I got them the right way round. :)
Tin (hydr-)oxide is amphoteric, ie it acts as both an acid and a base.
In practice stannates are poorly absorbed by weak anionic exchange
resins, and better absorbed by strong type 1 cation exchange resins.
The reasons are complex, and I'd have to look them up - I am shaky on
the details, it was 40 years ago. Tin (hydr-)oxides are... complicated.
One could try a pouring the 30 % (preferably less) peroxide on a batch of
suspended ion exchanger cation beads while stirring.
Yes, that is a good idea, better than a column. About 1 part beads to
say 50 parts 30% peroxide should do. You don't need a lot, in terms of
total quantity there isn't a lot of stabiliser in there.
If you can get the pH down to 5 or 4 with a few drops of eg nitric acid
(or any acid which won't hurt anything) it should work better.
Leave at least overnight, or better a day or two, but keep a close eye
on it.
note you want beads, not gel resin.
-- Peter Fairbrother
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