MICROENCAPSULATION OF TRIOCTILAMINE lN A POLYMERIC MA TRIX , FOR METAL UPTAKE FROM AQUEOUS SOLUTIONS . 145

Microencapsulation of extractants in polymeric matrices constitutes a new method for treating industrial residues and mining di lute aqueous solutions, to recover or remove efficiently their heavy metal contents. The system is based on lhe extraction and sorption of metallic ions in a microcapsule (MC). This process presents the possibility to extract, separa te and concentrate the heavy metal contents from dilute solutions by means of a practical and simple process. ln this study it was investigated the synthesis and the hydrometallurgical capacity of the microcapsules containing trioctilamine (TOA) as extractant. The manufacture of these microcapsules was carried out by free radical suspension polymerization using different composition of styrene and divinylbenzene. As initiator it was used benzoyl peroxide. ln order to measure lhe hydrometallurgical capacity of MC, the content of the extractant inside them was previously determined. The results of the microcapsules preparation h ave showed that it was possible to obtain yields ranging up to 82% (mass weight). The total amount of TOA retained inside the microspheres varied from 0.43237 to 0.05244 mmol TOA/g MC. Copper and zinc uptake experiments were accomplished from aqueous solutions prepared at laboratory. The results of lhe experiments showed the high efficiency of the proposed hydrometallurgical method.