How to reduce the pollution of iron impurities to the hot-dip galvanizing bath?

In normal hot-dip galvanizing operation, it is stipulated that the mass fraction of iron in the hot-dip galvanizing bath should not exceed 0.05%. As the production progresses, when the mass fraction of iron in the hot-dip galvanizing bath accumulates to 0.2%, the production can no longer be carried out. In the production process of hot-dip galvanizing, it is inevitable to produce iron impurities and contaminate zinc, and it is also inevitable that iron impurities and zinc generate zinc dross (zinc-iron alloy). The zinc slag in the hot-dip galvanizing bath has great harm to the process performance of the hot-dip galvanizing bath and the quality of the zinc coating. In addition, measures must be taken to control the source of iron impurities in the hot-dip galvanizing bath as much as possible to reduce the pollution of iron impurities to the hot-dip galvanizing bath. To control the influence of iron impurities, the following measures must be taken:

1) Because zinc ingots contain iron, it is necessary to choose high-grade zinc, and do not use secondary or recycled zinc at will.

2) After the work piece has been etched by sulfuric acid and washed with water, it is then converted into one with dilute hydrochloric acid. In order to remove the insoluble iron sulfate remaining on the workpiece.

3) When dipping flux, the time should not be too long and the temperature should not be too high to reduce the production of iron salt.

4) Use non-steel zinc pot, such as ceramic galvanized pot.

5) All equipment and tools that are in direct contact with the hot-dip galvanizing bath must be made of low-carbon steel or low-silicon steel.

6) Try not to use high temperature work. It is necessary to ensure the stable heating of the hot-dip galvanizing bath technically and in terms of management systems, prevent drastic changes in the temperature of the hot-dip galvanizing bath, and reduce the corrosion of the inner wall of the steel zinc pot.