离子交换树脂对铀的静态和动态吸附行为研究

Study of Ion Exchange Resin's Static and Dynamic Adsorption Behavior for Uranium( Ⅵ)

利用规格为Φ40 mm×1200 mm的吸附装置模拟实际铀水冶过程工业生产过程,测得了在固定床离子交换吸附的穿透曲线,并进行了静态吸附实验,测得了不同浓度条件下的平衡吸附量.应用Freundlich与Langmuir等温吸附方程对实验数据进行拟合,结果表明两者都适合描述离子交换树脂对铀的吸附,说明铀的吸附过程受到液膜扩散和孔内扩散共同控制,同时得到了动态吸附容量是静态吸附容量的1.87倍左右.应用Bohart-Adams模型、Wolborska模型对穿透曲线进行拟合,相关系数均在0.92以上,模型得到的树脂吸附容量与液计吸附容量误差较小.对静态吸附与动态吸附的区别,本文提出了观点加以解释.

AΦ40 mm×1200 mm adsorption device was used to simulate the actual uranium hydrometallurgy process in industrial production,with the breakthrough curve got in an ion exchange adsorption fixed bed and the static adsorption experiment was carried out to measure equilibrium adsorption quantity under different concentration. Freundlich and Langmuir adsorption isotherm models are applied to fit experimental equilibrium data, which nium shows that both are suitable to describe the adsorption of ion exchange resin for uraand the process of the adsorption of uranium is controlled by liquid film diffusion and hole diffusion together, and the dynamic adsorption capacity is about 1.87 times that of the static adsorption capacity. Bohart Adams model and Wolborska model are carried out on the breakthrough curve fitting, of which the correlation coefficients are above 0. 92, the error between resin adsorption capacity of model and Liquid method is small. This article puts forwar a point to explain the difference between the static adsorption and dynamic adsorption.