Mass transfer of Er(III) between HBTMPTP dissolved in n-heptane and HAc-NaAc

The rate of extraction of Er(III) from aqueous acetate solutions at 0. 2 mo l/L ionic strength by HBTMPTP in n-heptane was studied by using a constant interfacial area cell with laminar flow at (30+/- 0. 5)degrees C. The inter facial activity of HBTMPTP was investigated at n-heptane/0. 2 mol/L (H, Na) Ac (pH=5. 00) interface, The rate of Er(III) extraction was measured at dif ferent chemical compositions by varying hydrogen ion, HBTMPTP, Cyanex 302 a nd chlorine ion concentrations, The effect of stirring speed, temperature a nd special interfacial area on the rate of extraction was also studied. The results showed that, under the conditions of the experiments, the overall rate is diffusion controlled, that the impurities of Cyanex 302 have the ef fect of synergistic extraction.