D001树脂静态吸附钕离子的热力学与动力学研究

Thermodynamics and Kinetics of Static Adsorption of Neodymium Ions with D001 Ion Exchange Resin

为达到Nd3+富集目的,实验研究D001树脂静态吸附稀土Nd3+过程。通过单因素实验优化平衡吸附条件,并研究树脂吸附稀土Nd3+的热力学和动力学特征。结果表明:T=293 K,pH=3.5,[Nd3+]浓度10 mmol·L-1条件下,树脂的饱和吸附容量达到698.9×10-3mmol·g-1;吸附过程遵循Langmuir等温方程,热力学参数为:ΔH=13.45 kJ·mol-1,ΔS=53.035 J·mol-1·K-1,ΔG=-2.09 kJ·mol-1。热力学函数ΔG<0表明D001树脂吸附Nd3+过程能够自发进行。准二级动力学模型能够很好拟合DO01树脂吸附Nd3+的过程并且其相关系数在0.99以上。吸附活化能Ea=1.04857 kJ·mol-1,反应控制步骤为膜扩散和颗粒内扩散联合扩散控制。

The static adsorption properties of D001 resin for rare earth neodymium ions was studied in order to enrich Nd3 ＋. Equilibrium adsorption conditions was optimized by single factor experiments, and the thermodynamics and dynamics characteristics of the resin adsorption of Nd3＋ were studied. It showed that, under the conditions of T=293 K, pH =3.5, [Nd3＋] = 10 mmol·L^-1 , the saturation adsorption capacity of resin was 698.9 × 10 -3 mmol ·g^-1. The adsorption behavior of D001 resin for neodymium ions was based on the Langmuir isotherm equation. The adsorption thermodynamic parameters were： △H = 13.45 kJ ·mol^- 1, AS = 53. 035 J·mol^-l·K^-1 , △G =-2.09 kJ·mol^-1. AG 〈 0 implied that the process of D001 resin adsorption neodymium ions could occur spontaneously. The correlation coefficient was greater than 0.99. The activation energy Ea = 1. 04857 kJ·mol^-1. The controlling step was joint diffusion of liquid film diffusion and particle diffusion in the course of adsorption.