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Excess Sludge in Phosphating Bath

Dear Sir

We have a 9 stage spray pre-treatment line.

We are facing a problem we get lot of sludge in our phosphating tank.

Can any one help me on this. We maintain, low toner, temp 50, T.A. 24, F.A. 0.8 and still we have this problem.

Regards

Amitabh Tiwari
Paint Shop - Noida, U.P., India
2005

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Not enough info. on your system to fairly comment. What is your bath loading , component size and material.?

What nozzle type and at what pressure are you spraying. How do you control replenishment: batch additions or continuous feed.? How do you control temperature and how is you your tank heated. ? How much sludge are you generating.?

Is it a "conventional" low zinc process ? : What are your zinc levels .? How do you desludge ? continuous process or shut it all down and dig it out.

More info needed.

ALAN THOMAS
- Chandler, Arizona, USA
2005

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You didn't mention what kind of phosphate bath you have. A bit of sludge in an iron phos bath is normal. You may want to look at your feed water. I've found RO water (low salts, practically no hardness) will decrease sludging in my application.

Trent Kaufman
electroplater - Galva, Illinois
2005

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We are controlling the parameters with the latest electronic gadgets and removing the sludge continuously some times manually if our sludge removal system does not work on off days.

Regards

Amitabh Tiwari
- Noida, U.P., India
2005

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2005

Dear Sir

We are using Tri-cation Zinc Phospahte.

Regards

Amitabh Tiwari
- Noida, U.P., India

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At what pressure is your phosphate being sprayed?

What nozzle type are you using. Eg. hollow cone whirl jet ?

Low pressure , high volume preferable.

Have you the capability of changing your parameters. Try increasing your FA 0.1 at a time and observe any changes in coating characteristics.

Are you judging the sludge levels based on a measurement of "what's in the Tank " or are you looking at the amount being removed by your equipment and thinking "that's a lot of sludge ! "

ALAN THOMAS
- CHANDLER, Arizona, USA
2005