When using acid zinc plating additives brightener, how to control the concentration ratio of potassium chloride and zinc chloride in the plating solution?

When using acid zinc plating additives brightener, how to control the concentration ratio of potassium chloride and zinc chloride in the plating solution?

Wed Mar 15 18:12:57 CST 2023

As we all know, potassium chloride and zinc chloride are the main salts of zinc acid plating solution. So how do we control the concentration ratio of potassium chloride and zinc chloride in the bath when we lack analytical conditions in the production process of using acid zinc plating additives?

According to the site experience and the characteristics of BZ-528, an acid zinc plating additive, Bigley Technology has analyzed the following three measures:

1. Density method. In the zinc acid plating solution, the concentration of potassium chloride is 180~220g/L, which is far greater than the concentration of zinc chloride and boric acid. Therefore, we can establish a method to control potassium chloride as the main salt, that is, use a density meter with a range of 1.10~1.20 to measure the density of the plating solution, and control the density of the plating solution between 1.16~1.20. When the density of the plating solution is lower than 1.16, the concentration of the plating solution is insufficient, and potassium chloride, zinc chloride and boric acid need to be added; When the density of the plating solution is higher than 1.20, the concentration of the plating solution is too high and needs to be diluted with water.

2. Scale addition method. Because the concentration ratio of zinc chloride and potassium chloride in the plating solution is about 3:1, zinc chloride and potassium chloride that are taken out of the workpiece and filtered during the production process are also consumed according to this ratio. In order to maintain their proportion balance, we can supplement potassium chloride and zinc chloride according to this ratio. Even if there is a proportion deviation in the plating solution, the deviation can be reduced by adding potassium chloride and zinc chloride according to this proportion.

3. Hull groove method. Although the density method and proportion method can maintain the stability of the plating solution for a long time in the production process, the concentration ratio of potassium chloride and zinc chloride in the plating solution will have a certain deviation. Therefore, it is necessary to regularly conduct Hull cell test or small cell test on the plating solution to verify the condition of the plating solution and make adjustments.

Therefore, in the absence of analytical conditions in the production process of using acid zinc plating additives, we can control the concentration ratio of potassium chloride and zinc chloride in the bath according to the above three measures to maintain the stability of the bath. If you are interested in acid zinc plating additives, please contact Bigley customer service for free samples and detailed technical information!

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