Trouble shooting in phosphating plant

Trouble shooting in a phosphating plant


S. No.





Coarse crystal Low accelerator Add accelerator


Patchy coating Low concentration of phosphate solution Add phosphate solution


Dark brown colour of both solution and substrate Excess iron Add accelerator


Yellowing after passivation Poor water rinse, excess passivation solution, improper draining of bath solution, insufficient drying Good water rinse, dilute passivation solution, proper draining, thorough dry off


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2 Responses to Trouble shooting in phosphating plant

  1. John Willson says:

    How high of a drying temperature will a Zinc Phosphate and Iron Phosphate experience before causing any type of surface structure degradiation?

    • eramanath says:

      It depends on the size and nature of the component. Yet,the recommended drying temperature is 105 – 115 deg C /10-20 min. to drive away the residual rinsed water from the phosphated components. If the components have any rubber or any plastic component please check the heat tolerance of the parts with the suppliers.

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