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Investigation of optimal conditions for zinc electrowinning from aqueous sulfuric acid electrolytes

“…The effect of electrolyte composition on both the current yield and the deposit morphology has been investigated extensively [4][5][6][7][8][9], but the conclusions reported are not perfectly consistent: according to Adcock et al [6], higher current yields are obtained for high H + /Zn II ratios, in contradiction with other papers [7][8][9][10]. In particular Saba and Elsherief [8] reported high yields for zinc(II) concentrations above 0.6 M and moderate concentrations of acid.…”

“…Heavy metals were reported to change the mechanism of the deposition, as with lead [14], manganese [10], or antimony [15,16]; any species that could catalyse hydrogen evolution have detrimental effects on current efficiencies for zinc deposition, such that they have to be depleted from the electrolyte to extremely low concentrations. In addition, organic substances e.g., glue [8,15,17], urea or naphtol derivatives [6] have been commonly employed.…”

“…Since the combined process is to be operated with only sluggish circulation of the fluid in the various parts of the cell, the effect of hydrodynamics on the deposition was not investigated. Voltammetry and chronopotentiometry were used for preliminary tests, prior to investigating the deposition in a Hull cell, as used previously [10,16] with other deposition baths, allowing a large range of current density to be investigated. The effects of the bath composition on current efficiencies and deposit morphologies were also determined.…”

Copper deposition at segmented, reticulated vitreous carbon cathode in Hull cell

“…[28][29][30][31][32][33] The classic Hull cell, which utilises a continuous planar metal substrate cathode, has been widely described in the literature. 19,24,[34][35][36][37][38] Segmented cathodes have also been used in the Hull cell for zinc electrowinning on aluminium. The cathode was divided in 10 electrically isolated segments which allowed the calculation of the current densities across the cathode and the study of the zinc morphology in each electrode by SEM and X-ray analysis.…”

“…The cathode was divided in 10 electrically isolated segments which allowed the calculation of the current densities across the cathode and the study of the zinc morphology in each electrode by SEM and X-ray analysis. 35 The purpose of this paper is to demonstrate the use of a Hull cell with a planar carbon cathode and segmented planar and three-dimensional RVC cathodes 33 and compare their performance during the removal of copper ions. Current vs. potential curves were monitored during the deposition of copper from dilute solutions in a sulphate electrolyte at pH 2.…”