Studies on high density anion exchangers

Abstract

Most commercially available anion exchangers are not suitable for the continuous countercurrent fluidised-bed ion-exchange technique because of their poor wet absolute densities and poor settling characteristics. A few high density anion exchangers were developed by the treatment of commercially available anion exchangers with nitric acid-potassium bromate. The effect of the temperature of chemical treatment on the ion-exchange capacity and wet absolute density of the modified anion exchangers was studied. Anion exchangers prepared under optimised conditions were characterised with respect to ion-exchange capacity, wet absolute density, rate of exchange and rinse characteristics. Of one selected product prepared under optimised conditions the elutriation velocity was determined in order to assess its utility in continuous countercurrent fluidised-bed ion exchange.