Fabrication an‎d performance eva‎luation of lead dioxide (Ti/PbO2) electrode in electrowinning of lead

4/8/2026 12:00:00 AM

Although the conventional method of extracting lead from primary an‎d secondary sources is based on pyrometallurgical processes, these methods face challenges due to high energy consumption, dependence on fossil fuels, emission of the greenhouse gas CO₂ an‎d the release of toxic gasses such as SO₂ an‎d NOₓ as well as lead-containing dust. Therefore, the development of low-temperature alternatives based on hydro-electrometallurgical processes has attracted considerable research interest. Although several methods for lead extraction have been developed on a pilot scale, none of them have yet been industrialized. One of the major challenges in the industrialization of the electrowinning of lead is the development an‎d application of an anode that maintains acceptable chemical, electrochemical an‎d physical stability in the presence of fluorinated electrolytes an‎d undesirable anodic reactions. This study focuses on the electrodeposition an‎d performance enhancement of lead dioxide (β-PbO₂) as a stable anode for the electrowinning of lead. After eva‎luating the effects of electrolyte additives an‎d the presence of an α-PbO₂ interlayer on electrode performance, it was found that the use of the interlayer an‎d additives such as fluoride ions, copper ions an‎d sodium dodecyl sulfate (SDS) had a direct an‎d positive impact on improving the electrocatalytic properties an‎d performance of the lead dioxide electrode. Accordingly, the response surface methodology with a central composite design was used to optimize the fabrication conditions of the Ti/α-PbO₂/β-PbO₂ electrode. The influencing variables related to the interlayer an‎d the active layer were investigated simultaneously in a designed experiment considering multiple responses. The results showed that increasing the current density increased both the coating charge an‎d the oxygen evolution potential (OEP), while all variables had a decreasing effect on the voltammetric charge. Finally, a multi-criteria optimization was performed using Design Expert software an‎d three anodes were selec‎ted for further eva‎luation in the electrowinning of lead. Electrochemical tests showed that the optimized electrode fabricated at an α-layer current density of 50.25 A/m², a β-layer current density of 141.50 A/m², a temperature of 35 °C, an‎d an acid concentration of 0.33 mol/L resulted in a 17-fold improvement in performance, a 2.5-fold increase in durability, an‎d a reduction in OEP from 2.05 V to 1.81 V. The long-term stability of the optimized anode was confirmed in a simulated lead electrowinning environment, demonstrating a lifetime of over four months in HBF₄ solution. In addition, the optimized electrode performed well under conditions similar to those at Engitec (a leader in lead electrowinning), including a cathodic current efficiency of 97.7%, an anodic current efficiency of 65.1% an‎d a specific energy consumption of 0.89 kWh per kilogram of lead, outperforming the company’s commercial anode under identical conditions.

الكترووينينگ سرب , الكترونشست آندي , الكترود دي اكسيد سرب , طرح مركب مركزي

Electrowinning of lead , Anodic Electrodeposition , Lead dioxide electrode , Central Composite Design

Hadi Sharifi doraabad

Dr. Alireza Zakeri- Dr. Adeli