For phosphating solution, ZnO 99.7% is generally produced by indirect method. Zinc oxide mainly provides zinc ion in phosphating solution, which is the main component of phosphating film. Zinc oxide is reacted to obtain zinc phosphate, which can be used for anticorrosion and rust prevention on metal surfaces, that is, zinc-coating is formed on the metal surface as an anti-rust pigment.

The reaction formula of the whole phosphating solution:

Phosphoric acid + zinc oxide → zinc dihydrogen phosphate + water

+ zinc oxide → + water

The concentration of zinc dihydrogen phosphate in production must be effectively controlled to achieve the goal.

First, the quality indicators