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Lead alloys have been widely used in the hydrometallurgy domain owing to their excellent corrosion resistance and electrocatalytic performance.In the field of hydrometallurgy, the corrosion resistance of lead alloys with different microstructures plays an important role in the production cost as well as the quality of cathode products.Furthermore,the electrocatalytic performance of lead alloys is also related to their microstructure.Therefore, the corrosion resistance and electrocatalytic activity of lead alloys are two important reference indicators for evaluating their performance.Currently, strategies for improving the performance of lead alloys are divided into optimization of alloy composition and plastic processing deformation.In this paper, the effects of alloy optimization of alloy composition (mainly Pb-Ag alloy series and Pb-Ca-Sn alloy series) and rolling on the corrosion behavior and electrochemical behavior of lead alloys were briefly reviewed, and the corresponding prospects were made.

The aim of copper hydrometallurgy is to produce high-quality cathode copper with the lowest energy consumption and the highest current efficiency. How to achieve this objective has become the focus of research. The anode material significantly influences the anode overpotential, current efficiency and cathode copper quality. Therefore, developing energy-saving anodes holds great practical significance for the copper electrowinning industry. The introduction of alloying element such as Ag, Ca, Co and Re into the lead alloy anode can enhance the mechanical strength of lead alloy, inhibit lead dissolution, and improve its electrocatalytic activity and corrosion resistance; the fabrication of composite anodes with active layers such as β-PbO2, IrO2-Ta2O5, TiB2/β-PbO2 and Co3O4 on conductive substrates, which possess excellent conductivity and catalytic activity, can enhance the anode’s corrosion resistance and reduce the oxygen evolution overpotential; it is found that graphite, lead with a three-dimensional structure and the PANI/Co3O4 composite can enhance both the active specific surface area and current efficiency of anode. By adjusting the copper acid ratio in the electrolyte from 0.25 to 0.30, and adding guar gum, thiourea and Co2+, the performance of the anode can be enhanced and the quality of the cathode copper can be improved. Furthermore, optimizing process conditions such as the temperature of the electrolyte and electrode spacing can also impact the anode’s lifespan and catalytic activity. In this paper, energy-saving measures for hydrometallurgical copper refining were mainly introduced from three aspects: the development of oxygen-evolving anodes, adjustments to the solution system, and optimization of process parameters. Finally, the future development direction of energy-saving in copper electrowinning was discussed.

In order to obtain PbO2 electrode with low cost, high catalytic activity and long life for manganese electrowinning, a carbon fiber/Ni - CoOx/Sn - SbOx/β - PbO2 - CNT composite electrode was prepared by adding bottom and intermediate layers on the carbon fiber substrate through electrochemical deposition and sintering. Galvanostatic polarization curve, Tafel curve and other electrochemical methods were employed to study the catalytic activity and corrosion resistance of the electrode. Results showed that the as - prepared carbon fiber electrode had a bottom layer of Ni - CoOx, an intermediate layer of Sn - SbOx, and a surface active layer of β - PbO2 - CNT. Adding Ni - CoOx bottom layer and Sn - SbOx intermediate layer made the connection between the PbO2 surface active layer and the carbon fiber closer, and adding carbon nanotubes into the β - PbO2 surface active layer improved the corrosion resistance, chlorine evolution potential and electrocatalysis activity of the electrode.

In this paper, the research progress of aluminum - based alloys’ surface modification in sulfuric acid system and modification by adding modifier elements were reviewed. On the one hand, the corrosion resistance of aluminum alloy could be improved by surface modification in different sulfuric acid systems including pure sulfuric acid, sulfuric acid - tartaric acid, sulfuric acid - boric acid, sulfuric acid - oxalic acid, sulfuric acid - organic acid to produce an anodic oxidation film. On the other hand, by adding different modifier elements into aluminum - based alloys, it was found that Mn, Mg, Re elements could enhance the corrosion resistance of the aluminum alloy, while Cu, Si, Sc, Ga and Zr elements had an adverse effect on the corrosion resistance of the aluminum alloy. Besides, it was found that the corrosion laws of aluminum alloy in sulfuric acid solution were mainly pitting corrosion and microcell reaction, which provided a reference for the extensive use of aluminum alloy in hydrometallurgical industry and also for the development of diversified alloys.

In this paper, PbO2 anode was prepared by pulse electrodeposition. The effect of temperature and current density on the thickness, micromorphology, crystal structure and grain size, and the deposition process was proposed and demonstrated by XPS. Furthermore, the effect of temperature and current density on the current efficiency, overpotential, and charge transfer resistance was systematically investigated by electrochemical properties, and the corresponding mechanism was analyzed. The results exhibit that the optimized temperature of the plating solution is about 50 °C. The electrode prepared at the current density of 400 A/m2 exhibits the highest current efficiency, while the electrode prepared at the current density of 300 A/m2 presents lower overpotential (0.7548 V) and smaller charge transfer resistance. This work provides a reference for the efficient electrodeposition of PbO2 composite electrodes. [ABSTRACT FROM AUTHOR]

The performance of the anode varies from the impurity ions in the copper electrowinning process. This work focused on the variation of the electrochemical behavior of the Pb-0.06%Ca-1.2%Sn anode as the Fe ions (Fe3+ and/or Fe2+) existed in the electrolyte by electrochemical characterization. Copper electrodeposition experiments were conducted under a current density of 300 A/m2, with the Fe ion concentration in the electrolyte controlled within the range of 0 to 20 g/L and the Cu ion concentration maintained at 45 g/L at a temperature of 45 °C. The variation in the corrosion resistance, catalytic activity, and structural composition of the anode film layer was analyzed in-depth according to the presence of Fe ions. The results show that the structure of PbO2 on the surface of the film was changed as Fe ions doped into the anode film, and the oxygen evolution activity of the anode was also improved. However, the corrosion resistance decreased with increasing Fe3+ concentration. Furthermore, the addition of 2 g/L Fe2+ in the electrolyte containing 2 g/L Fe3+ led to an elevation in the corrosion resistance of the anode to some extent and further increased the oxygen evolution activity. [ABSTRACT FROM AUTHOR]