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Cost of sludge disposal

We manufacture electronics products using an aluminum chassis with chromate plating. We currently buy the plated chassis from an outside vendor. I've been tasked with estimating the cost of bringing the plating process in-house. My initial investigations show that the chromate conversion process creates a sludge for disposal. What should I estimate my sludge disposal costs to be?

thank you, Bob Carson Mfg Engr Manager

Bob Carson
Pullman, Washington, USA
2000

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Bob, I'd need more information to help you on this one. How large do plan on making this operation? How many parts do plan to process in what time period? What size tanks? What solution?

You will either be paying for the spent solution to be hauled away, or have to purchase the equipment to change the wasted solution into sludge and treated wastewater.

Then you'll probably want a sludge press to reduce the amount of sludge hauled away, and reduce costs. Reducing the H2O content also lowers the weight of the sludge. Seeing your question, I think I can assume that you are currently not producing hazardous waste. Using the sludge press will help you stay under generating more than 220 lb. per month, which means you'll be a CEQG (conditionally exempt quantity generator) according to CFR title 40.

Then you'll either have to treat the wastewater a second time for reuse in your processing line (perhaps with an IX system), or pay to have it hauled away also.

Lastly, the cost difference between having the sludge hauled to a landfill (and you being responsible for it till the end of time) and having it incinerated is astronomical!

Hope this helped you out some, feel free to ask for more info if you want!

Benjamin Curto
Ponderay, Idaho, USA
2000

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I would like to obtain more information on the sludge press process/equipment. We operate a chromate conversion process for aluminum products. We have five 110 gallon tanks which, when spent, must be turned into sludge and hauled out as hazardous waste. Presently, we burn the spent solutions to evaporate off the liquid. The sludge is then hauled out while the evaporated liquid is sent to drain.

Is the sludge press technique the most commonly used treatment for spent chromate solutions? What about filter processes or vacuum distillation?

Any comments are appreciated.

Becky Marquette
- Salt Lake City, UT
2001