The authoritative public forum
  for Metal Finishing since 1989
-----

Steel Wool for Copper Removal from large rinse tank after copper strike

Q. Ok here is my question. Seems I cannot find any useful information on the process. I have a 2225 gal transfer shuttle located after my Cu strike bath. It gets a ton of drag out I tested the bath on Tuesday after start up and I have 36 ppms of copper already. So I was wondering if anyone has tried to run copper waste water over 00 steel wool ⇦this on eBay or Amazon [affil links] chambers and if so at what capacity would the amount of steel wool be per ppm or ug/l of copper concentration. Now I do know most steel wool has oil on it so this process would only be used at the end of the week and not during production. Does flow rate matter? Any info would be welcome.

Ed Barriager
Waste Water Treatment - Michigan
February 15, 2012

---

February 16, 2012

Cyanide strike, or non?

I'd be wary of using that method on a cyanide bearing waste. You would be apt to generate iron cyanide complexes, which are not amenable to chlorination and are quite difficult to remove.

Dave Wichern
Consultant - The Bronx, New York

---

February 24, 2012

Hi Ed
My first reaction would be to reduce the dragout. Why pay to neutralise expensive chemicals that you could use?
Simplest is to allow the parts to drain (but not dry out) over the plating bath - platers frequently skimp on this - aim for 30 sec or so.
Second use a fine demin spray to wash back into the tank. A small garden spray works well, costs almost nothing and does not add much to the tank volume.
It is also common practice to use dragout water when the tank needs topping up, again returning chemicals to where they should be.
Now to the wire wool. Cyanide copper plating is used because it does not form an immersion deposit, so I don't think it would work.
If your process is sulphate based, it should work and a simple trial in a bucket should show if it is worth while.
Two final points. Wire wool is expensive, any scrap steel product would do. Finally if you are tempted to degrease steel wool, avoid drying it. Fine clean steel wire wool is highly flammable - it is often used to start camp fires. I know this seems unlikely, so feel free to try it.
One very reliable way to get a fire without matches uses a car battery and some wire wool.

Geoff Smith
Hampshire, England

---

I like Geoff's reply.
You could set up a small "plating" tank with close anode-cathode spacing and with very good solution flow thru this tank and back to the rinse tank, you could recover a fair bit of the copper, but nothing else. Look at a video clip on the processing of copper ore.

James Watts
- Navarre, Florida
February 25, 2012