Resumo

ASCENSAO, C.; CIRIACO, L.; PACHECO, M.J.  e  LOPES, A.. Metal Recovery from Aqueous Solutions. Port. Electrochim. Acta [online]. 2011, vol.29, n.5, pp.349-359. ISSN 0872-1904.  https://doi.org/10.4152/pea.201105349.

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%.

Palavras-chave : metal recovery; copper; lead; cadmium; zinc.

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