plating, anodizing, & finishing Q&As since 1989
Regenerating loose ion exchange resin
August 7, 2010
I have a small mixed bed filter filled in with ionac nm 60 by 25 liters. I could separated both resins by simple steps because anion is lighter then cation. Now I want to regenerate both by HCl 5% and NaOH 4%. Since I don't have column or bed to do that I need your help how to do the regeneration.
Or I am asking you ; Could the resin be regenerated by immersing it in a small bowl? What I have in mind : I fill the bowl with regenerant of 5 and 4 % (volume is 12.5 liter each) and I immerse the resin in it for 30 minutes. There after I rinse and rinse them by replacing the water with clean water until the pH is 5.
Thanks so much for everybody's kind help.
operator - Jakarta, DKI, Indonesia
August 12, 2010
If you can make a good separation, then your procedure should work. Regeneration in a vessel with flow through the resin is much more effective, however, and will require much less rinse water. You can make a simple vessel with a short length of sewer pipe or large diameter PVC pipe.
For regeneration in a vessel, you need to use at least 9 kg of HCl (100% basis) for the cation resin and 6 lbs of sodium hydroxide (dry weight basis) per cubic foot of anion resin.
After rinsing, you will also need to re-mix the two resins in order to get good results. It is best to do this by bubbling oil-free air through the resins when there is just enough water to cover them.
consultant - Cleveland Heights, Ohio