The electrolytic extraction of non-ferrous metals in the hydrometallurgy industry involves common solution systems such as chloride solution, sulfate solution, and chloride sulfate mixed solution. The graphite, lead alloy and Lead dioxide anode used by traditional methods have various problems in practical application, especially the problem of secondary pollution. In recent years, with the increasingly strict environmental requirements, they have been gradually replaced by precious metal oxide anode with titanium as the substrate.
When the electrolysis solution system is different, the gas released by the anode is also different. When the anode operates in different environments, the active components of various coatings with different performance requirements are also different. After years of research and practice, Baoji Changsheng Titanium Company has produced several kinds of titanium anodes with different formulations for hydrometallurgy, which have been successfully used in electrodeposition of Manganese sulfate, Copper sulfate, Cobalt chloride, Cobalt sulfate and other metals, it has effectively reduced energy consumption and achieved significant economic benefits.
When electrolyzing and extracting non-ferrous metals in this solution, a chlorine evolution reaction occurs on the anode. Active coating requires low chlorine Overpotential, good conductivity, strong chlorine corrosion resistance and long service life of anode. The requirements for anodes are relatively high. Based on the characteristics of the solution system, Baoji Changsheng Titanium Company has adjusted the coating brushing frequency. After a large number of formula screening tests, two active elements have been selected and added to increase the anodic oxidation potential and extend the service life.
The lead silver anode is often used for metal electrodeposition in this solution system, but during the electrolysis process, the anode will dissolve, which not only consumes the anode material but also affects the service life of the anode. Moreover, the lead dissolved in the solution will precipitate on the cathode, causing an increase in lead impurities in the product and reducing product quality. When electrodepositing metal from sulfurate solution, oxygen evolution reaction mainly occurs on the anode. The requirements for the anode include high electrocatalytic activity, good durability to oxygen, and long working life of the anode.
In order to overcome the problems existing in the use of traditional anodes, our company developed a titanium anode with a specific coating formula after years of effort and continuous exploration. The main element is Ir, and a ternary or quaternary formula coating is added. This has strong electrocatalytic activity, good conductivity, effectively reducing the cell voltage, and also improving the service life of the anode.
During electrolysis in a mixed system solution, oxygen and chlorine evolution reactions occur on the anode. When the concentration of sulfuric acid solution increases, the oxygen evolution reaction on the anode intensifies, which reduces the efficiency of chlorine release current and affects the service life of the active coating anode. The formulation coating developed by Baoji Changsheng Titanium company adds the active element palladium to the Ir and Ru elements, which is beneficial for the chlorine evolution reaction and inhibits the oxygen evolution reaction. It can suppress the adverse effects of sulfate ions on the electrodeposition of metals in mixed solutions and extend the service life of the anode.