A novel approach for predicting the separation in column chromatography elution using microchannel countercurrent reverse extraction: Essential correlation of confined mass transfer kinetics

This study contributes to addressing the critical challenge of efficiently separating neighboring rare-earth impurities for production of high-purity compounds. The complexity of predicting separation behavior in column chromatography arises from the intricate microfluidic dynamics within the resin particle channels. A novel strategy was introduced for predicting the separation factors of Y and Ho during column chromatography elution processes. Microchannel countercurrent reverse extraction was employed as a model experiment to optimize the separation technology of rare earth elements. It was found that a lower flow rate and concentration of hydrochloric acid as the eluent similarly enhance the separation factors of Y and Ho ions in column chromatography, as well as their separation coefficients in microchannel countercurrent reverse extraction. A linear regression model based on SKLearn was utilized to quantitatively predict the separation efficiency of adjacent rare earth elements during column chromatography elution processes. Additionally, molecular dynamics simulations conducted with GROMACS were employed to identify the essential correlation between column chromatography elution and microchannel countercurrent reverse extraction. These simulations indicate that a lower flow rate of hydrochloric acid eluent is beneficial for increasing the competitive mass transfer difference between hydrogen ions and rare earth ions with varying hydration radius.