Prediction of Flooding in a Pulsed Packed Column for Continuous Pertraction of Dysprosium by an Emulsion Liquid Membrane

Abstract

For the first time, Dysprosium was extracted by the novel method of emulsion liquid membrane in a pulsed packed column in a continuous process. Emulsion liquid membrane (ELM) was comprised of D2EHPA (di-2-ethylhexylphosphoric acid) as carrier and Span 80 (Polysorbate 80) as the surfactant in kerosene as the diluent and nitric acid as internal phase. In this work, the packed column was characterized from a hydrodynamic point of view including flooding condition and holdup at flooding points. Operational parameters affecting the flooding points, such as pulsation intensity and flow rate of continuous and dispersed phases have been studied. It was found that increase in pulsation intensity up to 1.5 cm/s and phases flow ratio up to 1.5 cause the reduction of the maximum throughput of the column. Furthermore, two new empirical correlations are proposed for the prediction of holdup at flooding points and flooding velocities with a mean deviation of 2.92% and 1.37%, respectively. The results also demonstrate that about 99.7% of Dysprosium was extracted under specific conditions. Also, recovered membrane phase showed an extraction efficiency that was as high as the fresh membrane phase. These results confirmed the possibility of applying of an ELM for continuous extraction of Dysprosium.