Volume 16 (2005) Issue 1 Pages 76-82
Inorganic ion-exchangers zirconium antimonophosphate (ZrSbP) and zirconium phosphotungstate (ZrPW) are synthesized and characterised as weakly acidic ion exchangers by potentiometric titrations against alkali metal hydroxides. Chemical composition, ion-exchange capacity for alkali and alkaline earth metal ions, distribution coefficients for a number of metal ions, effect of heat treatment on ion-exchange capacity are reported for the ion-exchangers. ZrSbP and ZrPW show excellent chemical stabilities towards most of the aqueous media except alkaline solutions. The exchanger ZrSbP loses only 30% of its ion-exchange capacity upto 200°C. An extensive study of distribution coefficients for various metal ions suggests that ZrSbP is selective for Fe2+, Pb2+ and Ba2+ ions while ZrPW is selective for Fe3+ ions. Structural studies of these materials are carried out using XRD, IR and chemical analysis.