Journal of Chemical Technology and Biotechnology, Vol.79, No.9, 935-945, 2004
Removal of cupric ions from acidic sulfate solution using reticulated vitreous carbon rotating cylinder electrodes
The potentiostatic deposition of copper from acid sulfate solutions (0.50 mol dm(-3) Na2SO4 at pH 2 and 298 K) was studied at four porosity grades (10, 30, 60 and 100 pores per linear inch, ppi) of reticulated vitreous carbon (RVC) rotating cylinder electrode (RCE). The rate of removal of cupric ions from a 200 cm(3) volume of electrolyte was examined as a function of the grade of RVC foam, the electrode potential and the initial cupric ion concentration. For the 100 ppi material, the product of the mass transport coefficient and the electroactive area per unit volume of electrode (k(m)A(e)) was equal to 0.28 s(-1) at a potential of -500 mV vs SCE for an initial cupric ion concentration of 0.85 mmol dm(-3) and a constant rotation speed of 1500 rev min(-1). Under the experimental conditions, an initial dissolved copper concentration of 63.5 ppm could be reduced to < 0.1 ppm in approximately 60 min using a 100 ppi RVC RCE. SEM studies showed some non-uniform deposition of metal due to heterogeneous nucleation of copper together with the development of rough deposits. (C) 2004 Society of Chemical Industry.
Keywords:batch electrolysis;copper deposition;cupric ion removal;electrode area;mass transport;reticulated vitreous carbon (RVC);rotating cylinder electrode (RCE);three-dimensional electrodes