ChemInform Abstract: The Hydrous Niobium(V) Oxide Ion Exchanger. Part 5. Effect of Heat Treatment on the Sodium Isotopic Exchange Rates Between Hydrous Niobium(V) Oxide in Na+ Form and Aqueous Solutions.

Abstract

ChemInform Abstract Radiochemical measurements of the sodium isotopic exchange rates of the Nb2O5 exchanger in Na+ form indicate that the rate is controlled by particle diffusion and increases with increasing temp. of the heat-treatment in air. The increase in the exchange rate is attributed to a decrease in the effective particle size caused by cracks which develop within the particles, and by an increase in the Na+-diffusion coefficient due to an increase in the pore size of the exchanger.