EXTRACTION OF CADMIUM WITH TRILAURYLAMINE-KEROSENE THROUGH A FLAT-SHEET-SUPPORTED LIQUID MEMBRANE

Cadmium has been extracted as a chloride complex through a hat-sheet-s upported liquid membrane (SLM), using the tertiary amine Alamine 304-1 (mainly trilaurylamine or TLA) in kerosine. The typical permeability of the membrane was 1.1 x 10(-6) m s(-1). The rate Limiting step is di ffusion through the membrane. The cadmium loading of the extractant at the feed-membrane interface is high. Trilaurylammonium chloride cryst allizes at the surface of the membrane above 0.2 M TLA, This salt bloc ks the pores and lowers the extraction rate up to a factor of 3. Apart from this blocking effect, the permeability through the membrane is d escribed well with the presented model, using physically realistic par ameter values. When the precipitation can be minimized, the system has good potentials for the extraction of cadmium chloride complexes. (C) 1998 Published by Elsevier Science B.V. All rights reserved.