Diffusion coefficients of trivalent rare earth/actinide ions in acid and alkaline aqueous solutions

摘要

Leaching is one of the key process of rare earth(RE)element recovery.This paper was set out to validate the effectiveness of acid/alkali in RE leaching by measuring the limiting ionic conductivity(λo),self-diffusion coefficient(Di)and overall diffusion coefficient(D_(ab))to obtain a clear insight on the transport properties of ions and salts in aqueous solution.The calculation diffusivity of D,which is diffuse individual ions in pure water and D_(ab)diffuse in chemical reagents were determined using Nernst-Haskell equation,applicable for 25°C.The results of Di were found to be consistent with experimental data from the literature where most of calculation and experiment data are less than 5% error.The final outcome had managed to confirm that NaOH is best reagent for most RE element leaching,which suits the common practice of the industry.