Method of liquid-liquid extraction using material exchange columns

Abstract

With the extraction method, a material exchange column with an ordered packing 2a or 2b on the basis of a plurality of layers 3 stacked parallel to the column axis and making point contact with one another is used. The packing 2a, 2b is perfused by a continuous and a dispersed phase in a counter current. The packing has a very large specific surface area of at least 300 m.sup.2 /m.sup.3 of packing volume. At the periphery of the packing 2a, 2b, the two phase streams are re-circulated into the packing at regular intervals through a rim seal composed of an elastic material not wettable by the dispersed phase. The rim seal is placed round the packing in the form of an elastic tube or pipe and seals the intermediate space between the internal column wall and the packing. A further improvement in the separating capacity can be achieved if pulsating operation is adopted. The method is characterized, in particular, in that an approximately constant high separating capacity is achieved with a high throughput per unit area over a relatively large loading tolerance of the column.

Dependencies are inferred from the claim text.