Metal Recovery from Aqueous Solutions

• Autor(a) principal: Ascensão,C.
• Data de Publicação: 2011
• Outros Autores: Ciríaco,L., Pacheco,M.J., Lopes,A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0872-19042011000500006
• topic: metal recovery; copper; lead; cadmium; zinc

Metal recovery by reduction of metal ions present in model solutions, containing one or more heavy metals, was performed. To prepare the model solutions, sulfates and/or chlorides of Cu(II), Cd(II), Pb(II) and Zn(II) were used, at pH 3.5. Assays were run in a one or two compartments cell, at different applied potentials, using a steel plate as cathode, a platinum plate as anode and an Ag/AgCl, KClsat as reference electrode. The metal recovery yield was determined by atomic absorption spectroscopy. The phases corresponding to the metallic deposits were identified by X-ray diffraction. For the solutions containing just one metal ion, the best metal recoveries and the corresponding applied potentials, obtained in a one cell compartment, were the following: Cu2+ 99% at E = -100 mV; Pb2+ 99% at E = -800 mV; Cd2+ 93% at E = 900 mV; and Zn2+ 38% at E = -1300 mV. The metal removals from the mixed solution of four heavy metals, after 4 consecutive chronoamperometries, performed in a one compartment cell, at the best applied potentials determined with the solutions containing only one metal ion, were the following: Cu2+ 99%; Pb2+ 68%; Cd2+ 92%; and Zn2+ 10%.