稀土离子在多孔阳离子交换剂内的扩散动力学

Diffusion Kinetics of Rare Earth Ion in Bidispersed Porous Cation Exchange Resins

研究了稀土离子在Amberlyst15、D001、XN1010多孔树脂内的自扩散。结果表明,扩散过程遵循二级分散扩散机制。用粒内扩散方程求算了有效粒内扩散系数e,将e分解为树脂孔道扩散系数p及树脂固相扩散系数s,p与该离子在外部溶液中的自扩散系数相近,而s接近于与实验用的多孔树脂交联度相同的凝胶树脂内的自扩散系数值。

Experiments for determining cerium isotope ion exchange rates with macroporous resins Amberlyst 15, D001 and XN1010 are discribed. The kinetics of the isotope ion exchange reaction has been examined by a simple theoretical equation of intraparticle effective diffusivity De in a porous ion exchanger. The ion exchange proceeds by diffusion within the macropores and the solid phase of the resin. De of cerium was affected by the concentration of the bulk solution C. and was separated into a macropore diffusivity Dp and a solid phase diffusivity D by the equation. The diffusion coefficients of the exchanging ion are shown to have the values in the macro-pores comparable with their valuse in the bulk solution and to have the values in the solid phase comparable with their values in gel resin with the same crosslinkage as the resins used for the experiments.