How do we analyze the zinc content in the alkaline galvanizing process?
Traditional titrimetric analytical methods
The determination of zinc in alkaline zincate bath is widely used in ammonia buffer solution with PH=10, the main element zinc and copper, iron, lead and other impurities are complexed with qing compound, and then formaldehyde is added to decertify the zinc qing complex to release zinc, and the zinc in the bath is titrated with EDTA standard solution.
This method actually has three disadvantages. Due to the sealing effect of impurities such as Fe3+, Cu²+, Al3+ and Pb2+ on the chromium black T indicator, Fe3+ and chromium black T can easily generate stable Burgundy complex. Compared with the complex formed by Zn²+ and EDTA, its stability is large, which makes the change of the end point of this method less obvious. In severe cases, there will be no color change. That's one thing.
Second, the use of cyanide will cause harm to the health of analysts and pollute the environment.
Third, due to the masking with formaldehyde, this will increase the means of analysis.
Why do titration analysis?
Because in the alkaline galvanizing process, with the temperature, cathode and anode area ratio and other changes in the production factors, often have an impact on the composition of the plating solution, only through the analysis of the assay can be more accurately know the plating solution lack of which components, which component is too much, it should be known that the composition of the plating solution, if out of adjustment, then it will cause plating failure (for example, additives out of proportion will result in the plating layer fogging).
Therefore, when customers use Bigely alkaline galvanizing additives, we will provide them with a good method of titration analysis, so that they can monitor the composition of the bath at any time, reducing the probability of coating failure.
Do you want to know how to operate titration analysis for alkaline galvanizing process to make it simple, safe and pollution-free? Please feel free to contact us.
