ABSTRACT

In this work it is presented the viability of the application of the liquid-liquid extraction to the separation of cadmium from wet phosphoric acid using a new technology, non-dispersive liquid-liquid extraction (NDSX), as separation technique. Preliminary batch tests were carried out in order to select the most adequate cadmium extractant. Kinetic experiments with coupled extraction-stripping steps were performed in two hollow fibre modules working with industrial phosphoric acid and an ammonium quaternary salt, ALIQUAT 336, as selective extractant diluted in kerosene. A high cadmium separation efficiency, better than 95%, was obtained with a feed phase flow rate equal to 2 ml/min. The cadmium concentration in the stripping phase was increasing with the cadmium loading of the organic phase.