高压离子交换螯合排代法分离稀土元素的研究——稳定区段的界面

THEORETICAL STUDY OF HIGH PRESSURE ION EXCHANGE CHELATE DISPLACEMENT CHROMATOGRAPHY USED FOR SEPARATING RARE EARTHS-BOUNDARY BETWEEN STEADY ZONES

本文阐明了速率塔板理论和精馏型平衡塔板理论界面方程的一致性及其条件,用中等交联度(8%)的磺酸型微粒树脂(30—40μ,40—60μ),以DTPA作排代剂,在75±3℃下用高压离子交换排代色谱法分离了稀土元素。实验验证了在高压离子交换排代过程中液膜扩散是离子传质的控制阶段,并决定着HETP;为在高压离子交换排代法中使用第一类排代剂(具有固定螯合剂浓度、pH和适量中性盐的螯合排代剂)提供了理论依据。检验了实验条件对HETP的影响并进行了讨论,证明Snyder公式适用于高压排代色谱法。

Expounding the equality between the equation based on the rate theory and that on the theory of equilibrium and its condition,using the micro-resins with the diameters of 30-40μand 40-60μrespectively and using DTPA as displacer to separate rare earths by high pressure ion exchange chelate displacement chromatography at 75±3℃,the report has experimentally shown that the film diffusion of ions is the control step and decides HETP,which provides the theoretical base of employing Displacer I(a displacer with certain chelate agent concentration,pH and various concentrations of neutral salt)into high pressure ion exchange ehelate displacement chromatography.By examing and discussing the dependence of HETP upon the experiment conditions we have proved Snyder’s formula is suitable for high pressure ion exchange chromatographic process.