Fe(OH)3胶体对铀的吸附行为

为研究地浸采铀工艺过程中Fe(OH)₃胶体对铀的吸附，利用在无水乙醇中制备的Fe(OH)₃胶体，研究了pH值、初始铀浓度及吸附时间等对Fe(OH)₃胶体吸附铀的影响。采用准一级、复合二级与Elovich动力学模型对数据进行了动力学计算与分析，结果表明Elovich 动力学方程更适合描述Fe(OH)₃胶体对铀的吸附行为。采用Freundlich与Langmuir等温吸附方程对实验数据进行了热力学分析和拟合，结果表明Freundlich模型更适合描述Fe(OH)₃胶体对铀的吸附行为。综合两种等温吸附方程，推测Fe(OH)₃胶体对铀的吸附属于不均匀表面的单层物理吸附。根据激光粒度分析与SEM分析结果推测，Fe(OH)₃胶体对铀具有较强的吸附性能，吸附主要是表面吸附。

Adsorption Behavior of Uranium on Fe (OH)3 Colloid

In order to study the adsorption of uranium on Fe(OH)3 colloid in situ leac‐hing of uranium ,the Fe(OH)3 colloid was prepared in absolute ethanol ,and the adsorp‐tion performance of uranium on Fe(OH)3 colloid was detected .The effects of pH value , initial uranium concentration ,and the contact time were analyzed .As for the adsorption dynamics ,the pseudo‐first‐order ,composite‐second‐order and Elovich dynamic models were comparatively calculated and discussed .The results show that the Elovich dynamic model is fit to describe the adsorption of uranium on Fe (OH )3 colloids .As for the adsorption thermodynamics ,the Freundlich and Langmuir adsorption isotherm models were applied to analyze and fit the experimental equilibrium data .It is found that the equilibrium data agree well with the Freundlich model .In conclusion ,the adsorption of uranium on Fe(OH)3 colloid belongs to the single layer physical adsorption of uneven surface .The laser particle size and SEM analysis results reveal that the Fe (OH )3 colloids show a good adsorption performance ,and the surface adsorption takes preced‐ence in the adsorption process .