Sciencemadness Discussion Board

Potassium Hydroxide sodium sulphite separation

Dwarvensilver - 4-11-2016 at 13:36

Hello all,
Part of what I do is arrange for unneeded chemicals to be disposed of. When I looked up the MSDS I found that a boiler chemical that I have about 45L to dispose of is 5-10 %w/w. KOH.

I started to evaporate off about 600mL to see how hard it would be to concentrate.

After evaporating off ~200 mL I put it aside, next day I have crystals growing in it, long clear monoclinic like Sodium sulphite. I think Sulphite cause the crystal habit is different than sulphate.

After fishing out some after drying an hr or so they started showing signs of dehydration, turning to white powder.
If it has sodium sulphite/sulphate in it, can it be or is it worth the effort to separate it for the KOH?

Thanks,

Dwarvensilver

Dwarvensilver - 5-11-2016 at 20:35

I checked the solubilities and I should be able to crystalize out most of the sodium sulphite i think. We shall see ☺

Hmm not many thoughts on the subject :(.

Note: this process is for me to collect KOH for synthesis, not to save money at work lol

It is really hard for me to dispose of tens of containers of chemicals when they can be used for experimentation and knowledge :D

[Edited on 2016-11-6 by Dwarvensilver]

[Edited on 2016-11-6 by Dwarvensilver]