A novel process is being developed for metal recovery from waste electrical and electronic equipment involving a leach reactor coupled to an electrochemical reactor. Metals such as Ag, Au, Cu, Pb, Pd, Sn etc. are dissolved from shredded electronic scrap in an acidic aqueous chloride electrolyte by oxidising them with aqueous dissolved chlorine species. In the electrochemical reactor: (i) chlorine is generated at the anode for use as the oxidant in the leach reactor, and, simultaneously, (ii) at the cathode, the dissolved metals are electrodeposited from the leach solution. The extended Butler-Volmer equation was used to provide predictions of the electrode potential dependences of partial current densities and, hence, total current densities, current efficiencies and alloy compositions for acidic aqueous chloride electrolytes containing Ag(I), Au(III), Cu(II), Pb(II), Pd(IV) and Sn(IV) species, together with dissolved chlorine. With judicious choice of kinetic parameters, the predicted total current density - electrode potential behaviour of such solutions was in good agreement with experimental data for a rotating Pt disc electrode. Reduction of dissolved chlorine at a Pt rotating disc electrode exhibited mass transport controlled behaviour, in agreement with Levich's equation over the potential range 0.3-0.9 V (SHE). This could form the basis of a linear sensor, possibly using a microelectrode for measurement and control of the dissolved chlorine concentration in the efflux of leach reactors and inlet to electrowinning reactors in the envisaged process.

Metal recovery from electronic scrap by leaching and electrowinning IV / Pilone, Daniela; G. H., Kelsall. - STAMPA. - 2:(2003), pp. 1565-1575. (Intervento presentato al convegno Hydrometallurgy 2003: Proceedings of the 5th International Symposium tenutosi a Vancouver, BC nel 24 August 2003 through 27 August 2003).

Metal recovery from electronic scrap by leaching and electrowinning IV

PILONE, Daniela;
2003

Abstract

A novel process is being developed for metal recovery from waste electrical and electronic equipment involving a leach reactor coupled to an electrochemical reactor. Metals such as Ag, Au, Cu, Pb, Pd, Sn etc. are dissolved from shredded electronic scrap in an acidic aqueous chloride electrolyte by oxidising them with aqueous dissolved chlorine species. In the electrochemical reactor: (i) chlorine is generated at the anode for use as the oxidant in the leach reactor, and, simultaneously, (ii) at the cathode, the dissolved metals are electrodeposited from the leach solution. The extended Butler-Volmer equation was used to provide predictions of the electrode potential dependences of partial current densities and, hence, total current densities, current efficiencies and alloy compositions for acidic aqueous chloride electrolytes containing Ag(I), Au(III), Cu(II), Pb(II), Pd(IV) and Sn(IV) species, together with dissolved chlorine. With judicious choice of kinetic parameters, the predicted total current density - electrode potential behaviour of such solutions was in good agreement with experimental data for a rotating Pt disc electrode. Reduction of dissolved chlorine at a Pt rotating disc electrode exhibited mass transport controlled behaviour, in agreement with Levich's equation over the potential range 0.3-0.9 V (SHE). This could form the basis of a linear sensor, possibly using a microelectrode for measurement and control of the dissolved chlorine concentration in the efflux of leach reactors and inlet to electrowinning reactors in the envisaged process.
2003
Hydrometallurgy 2003: Proceedings of the 5th International Symposium
electrowinning; metal recovery; electronic scrap
04 Pubblicazione in atti di convegno::04b Atto di convegno in volume
Metal recovery from electronic scrap by leaching and electrowinning IV / Pilone, Daniela; G. H., Kelsall. - STAMPA. - 2:(2003), pp. 1565-1575. (Intervento presentato al convegno Hydrometallurgy 2003: Proceedings of the 5th International Symposium tenutosi a Vancouver, BC nel 24 August 2003 through 27 August 2003).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/206990
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