In the production process of using alkaline zinc plating additives, lead ion impurities are not very common in the plating solution, but their impact on the plating solution is significant.
During galvanizing production, the main sources of lead impurities in factories are impure anodes and inferior chemical raw materials. When the lead impurity in the alkaline zinc tank reaches 5mg/L, the coating has been severely affected.
Lead ions will reduce the coverage ability of the plating solution. When there are too many lead ions in the plating solution, the rolling plating will not be able to deposit the coating; After galvanizing, the galvanized layer in the low current density area will be missed after being exposed to dilute nitric acid, and areas with plating solution will appear yellow brown or have black stripes.
Lead ions can also affect the passivation film of the coating. After color zinc passivation on galvanized workpieces, the passivation layer does not light up and a yellow interference color appears; However, blue and white zinc passivation makes it difficult to display blue color.
The treatment method for lead impurities in alkaline zinc plating solution is to add 2-3g/L zinc powder to the plating solution, stir thoroughly for 30 minutes, let it stand, filter it, and then add an appropriate amount of alkaline zinc plating additive to start production. If you want to learn more about alkaline galvanizing additives, please feel free to call us for consultation. Bigely Technology is always at your service.
