Solvent Extraction Studies for Removal of Hazardous Metals from the Sulfate Leach Solution of Electronic Wastes.

Abstract

With rapid industrialisation, the amount of e-wastes is in-creasing enormously in the world. In order to conserve res-ources and reduce environmental pollution, attempts are be-ing made to recover the valuables from such wastes. The present paper reports the studies carried out for separat-ion of metals viz.copper,cadmium,zinc and nickel expected from leaching of e-wastes. Initially, studies have been made to establish the condition required for cadmium extra-ction. The solvent,DEHPA was found suitable for extraction of cadmium and complete extraction can be achieved at pH 4.5 , O/A in 2 minutes from the sulfate solution . The studies carried out with model mixed solution containing copper, cadmium, zinc and nickel showed that copper can be selectively extracted with LlX84 leaving other metals in aqueous raffmate at O/A ratio 1 and above pH2. Subsequent-ly,the raffinate containing cadmium, zinc and nickel could be separated with DEHPA under the controlled pH.