Patrick, photographic grade Potassium Sulphite is sold as a 45% w/w solution, so 384 will dissolve easily, but maybe not quickly
Originally Posted by gainer
It's solubility in water is 655 g/l, substantially higher than 384, this is why Potassium salts are used in liquid concentrate developers
In fact the supplier I'm looking at doesn't sell photographic grade Potassium Sulphite as a solid instead 45% W/W containing approx 450g/l:
* 250 Kgs. HDPE Drum
* 30 Kg. HDPE carboys
* 1000 Liters Intermediate Bulk container (IBC)
* 20 MT Bulk Liquid Bag (Flexi bag)
In Germany BASF supply this grade, in the US Mallinckrodt Baker, it's standard.
So to answer your question, yes I have made up concentrated stock solutions of Potassium Sulphite and Carbonate. I've started using the Potassium salts when making up concentrates of my print developers, replacing Sodium Sulphite & Sodium Carbonate in the formulae with the Potassium salts and KOH. This is done commercially to allow higher concentrates which won't precipitate during storage.
Last edited by Ian Grant; 08-23-2009 at 04:16 AM. Click to view previous post history.