Extraction by solid stabilized emulsions

Abstract

A process for transfer by extraction, of at least one species from a fluid phase to a first liquid phase receptive to such species, comprises intimately contacting the fluid phase with an emulsion of the first liquid phase in a second liquid phase which is permeable with respect to such species and substantially immiscible in the first liquid phase. The emulsion is stabilized by the second liquid phase containing at least one substantially insoluble particulate solid which is substantially non-reactive to constituents contained in each of such phases in an amount sufficient to form a stable emulsion. Transfer of the species is from the fluid phase through the second solids-containing liquid phase to the first liquid phase. In one embodiment, the first liquid phase is lean with respect to the species to be extracted. In another embodiment, mass action is utilized to maintain a driving force by counter-transport of a different ion. Where all phases are liquid, one phase is regarded as the bulk phase and the first liquid phase termed the internal phase is contained in a surrounding membrane of the solids-containing second liquid phase or the external phase. Transfer may be from the bulk to the first liquid phase or vice versa. The bulk and internal phases are normally aqueous in nature.