Electrochemical and physical characterisation of lead-based anodes in comparison to Ti–(70%) IrO2/(30%) Ta2O5 dimensionally stable anodes for use in copper electrowinning

Abstract

The suitability of various dimensionally stable anodes (DSAs Ò ) was investigated in comparison to the conventional lead alloy anodes in the electrowinning of copper. DSA Ò plate and mesh specimens of composition Ti-(70%) IrO 2 /(30%) Ta 2 O 5 and lead-(6%) antimony were evaluated. The electrochemical behaviour of these anodes was studied by carrying out open circuit potential measurements, galvanostatic chronopotentiometry, cyclic voltammetry and chronoamperometry. Physical characterisation was done using a scanning electron microscope. It was observed that the DSA Ò plate anode exhibited the highest corrosion resistance followed by the DSA Ò mesh and lead anodes, respectively. The results also showed that during copper electrowinning using lead anodes, dissolution of the anode occurs while for both DSAs Ò marginal loss of coating was observed. The lead anode had the highest anode potential followed by the DSA Ò plate and mesh anodes, respectively. Overall, it was demonstrated that the DSA Ò plate anode is the most suitable anode for copper electrowinning.

Effects of Oxide Composition on Structure, Surface Morphology, and Oxygen Evolution Behaviors of IrO₂-Ta₂O₅/Ti Anodes Prepared at a High Temperature

“…The voltammetric charge is widely used to evaluate the active surface area of thermally prepared IrO 2 -Ta 2 O 5 /Ti anodes 8,[23][24][25][27][28][29][30][31][32][33]36,47,48 and is also defined as a double layer charge for these binary systems. 30,31 The double layer charge was determined by cyclic voltammetry in the potential range between 0.5 V and 1.0 V in this study, in which no Faradic reaction occur.…”

Dimensionally Stable Anodes (DSA®) for Electrochemical Water Splitting: Redox Properties, OER Kinetics and Mechanism at RuO2/ NiO Modified Electrodes in Aqueous Base

“…The driving potential needed for water oxidation can be written as E(i) = E e,cell + |η c | + η A + iR (2) where E(i) is the overall potential required to drive the reaction, E e,cell is the thermodynamic reversible potential, |η c | is the overpotential associated with the hydrogen evolution reaction at the cathode, η A is the OER overpotential at the anode and iR is the ohmic drop in the cell.…”

Investigation of lead base composite anodes produced by accumulative roll bonding

“…In other words, poor mechanical properties of common lead base anodes lead to such adverse effects as dimensional instability, longitudinal deformation, and creeping, which represent examples of behavior that give rise to breakage in the anode surface layer. Moreover, alloyed [6] and composited [7][8][9][10][11] lead base anodes have been restricted in their applications because of the process-related disadvantages (such as casting and rolling defects) [6,8,12,13], expensive methods and instruments (e.g., counter gravity infiltration [8], ultrasonic injection [14], thermal decomposition [15], plasma spray [16], high pressure hot pressing [17], and hydrogen sintering [17]), or high cost materials (like polyaniline (Pani) anodes with titanium scaffolds) [10][11][12][13][14][15][16][17][18][19]. Although many research attempts have been directed toward the improvement of lead base anodes, little has been gained by studies focusing on electrochemical properties while the majority of the problems, especially those associated with their mechanical properties and production costs, still remain to be resolved [5].…”