Remedy for sludge buildup

you can find Atotac or Rohm & Haas, they provide whole process and chemistry, including pre-treatment and post treatment.

I am familiar with nitric acid based, zinc, nickle and manganese automobile spray and dipping lines. It is critical to replenish these baths constantly, very slowly. What you do not want to do is dump a bunch of different chemicals or even one chemical into the bath 1, 2, 3, 4, 5, 10, 24 times a day. The large dose of chemical all at once settles to the bottom as sludge instead of combining with the bath. We designed and installed continuous monitoring and replenishing systems for a major vehicle manufacturer and reduced yearly sludge from tons to pounds, seriously. Free acid should also be monitored. Find a bath chemistry provider that can sell you one replenisher for use throughout the dipping cycle. The 3 metals rate of precipitation to the metal surface follow each other very closely ratio-metrically when the bath is tuned and one replenisher mix replenishes the elements lost.

I understand it may only be possible to monitor and add chemicals once or twice per shift or even per day but that is the biggest reason why you have so much sludge.

An industrial system properly engineered and supported to last and perform is definitely going to run into the low 6 figures USD. Chemical usage was also reduced by a very large percentage when this type of system is installed.

I'd be happy to answer any more specific questions that you might have.

I am sorry that I haven`t been to the Forum for a while, but I would greatly appreciate your knowledge on this matter. As I`m an old man and a newer younger person with a computer says that as long as it works on this, it will work out there. I`m no Chief Engineer,but it isn`t .Every 2 days we end up with 5 days worth of sludge. I would appreciate any help that you could give me and the Company that I`m with.

Sure, I will help as much as I can. If you can answer the following questions it will help me understand your process.

What type of plating line is it?

What are the parts? Size and area?

How thick of a plate are you trying to achieve?

Are you achieving that thickness?

How many stages to your plating process and what are they?

Is there electricity flowing in the problem bath?

What are the elements and type of acid used in the problem bath?

How often is the baths chemical makeup monitored and how is it monitored?

How often are chemicals added, what is added, and how much of each is typically added?

That should be a good start. Remember, a well balanced bath, and one kept just below chemical saturation and at the proper ph will produce little sludge.

One quick thing that I would do is send out a sample of the sludge and have it analyzed to see what you are dealing with as the main culprit falling out of the bath. If its ratio of chemical to chemical is similar to the baths ratio, too much of all are being added back. If it is just one of the elements something is wrong with the chemistry or process. If electricity is being used, verify the anodes and all connections are good. By the way, how do the parts look under a microscope after treatment? How do they hold up to salt spray corrosion testing?

It is a Zinc Phosphate Coating Line.The part size varies as to the part number.The area that they want to treat also varies.Sometimes we do ,but the process fails due to some unknown factor. There is 13 stages to the process,they consist of;Blast ,Remove ,3 Rinses,Activation,2 Zinc phosphate tanks,3 more rinses,2 Dryer Cycles.No electricity to bath process.Both Total Acid and Free Acid are monitered 3 times a day at the beginning of each shift.3 times a day if needed.Where would I send a sample of this sludge to be analized?

Chuck

I know a little about zinc phosphate coating process as it pertains to the removal of sludge from the bath. I represent a company that has sold over 200 filter systems specifically for the removal of sludge from zinc and iron phosphate bathes.

Let me know if this is the path your are going down.

Kurt

Chuck,

Sorry, I am new here and did not see the other replys to your message. The filter equipment I sell is used to continuously circulate the bath through a nominal 7 micron filter paper. The equipment automatically dries and discharges the sludge from the filter. We can typically keep your bath at a cleanliness of less the 200 TSS (total suspended solids).

Kurt