De - galvinization thoughts

[Hoary]

I know you can de galvinize metal by using acid, but it is possible to speed up the process using a low electric current? maybe it would speed up the acid reaction? Just a random thought looking for some wisdom.

[Rich Hale]

Wisdom is just to leave the galvanized alone and use another less toxic metal

[evfreek]

Hi Hoary. This is a very interesting thought, and I would like to investigate it further. The problem about the acid removal of galvanization is that it releases a fine mist of dilute acid droplets, which is corrosive. It also releases hydrogen, which is explosive. Finally, there is that stupid waste liquor which has zinc chloride in it. As far as pollutants go, zinc chloride is not that bad, but in a low pH waste product like this, it is more toxic and can release other worse heavy metals from the environment due to the acidity.

So, I looked into electrolytic methods to remove galvanization. What I found was very interesting. The reaction produces metallic zinc, so it does not have the energy to atomize hydrogen as badly. Most of the electrons emitted at the cathode go into producing metallic zinc, and not hydrogen. Furthermore, zinc does not accumulate in the effluent. The metallic zinc that is produced is usually fluffy and amorphous, more like a gray sludge. If this is bagged, it represents a huge reduction in volume and toxicity. But, can this product be used? Forget about that old Scientific American publication on rocketry. That is too dangerous. Instead, I propose using the sludge, which will be about 95% metallic zinc with the principal contaminant being oxygen, as an additive to blacksmith paint/primer. Finely divided zinc, in the correct base, has beneficial effects in outdoor primers.

The main reason that this reclamation process is not used commercially is that the electricity costs money, and it takes up time and space. I would feel better about spending a small amount of money on electricity and reusing my derusting setup to capture some of that zinc into metallic sludge. Any thoughts? :)

[Ten Hammers]

Yeah, what Rich said..... From time to time I weld galvanized at work ( MIG, with a fan blowing across ). I also from time to time remove galvanized from some stuff here at home with muriatic. I have had the fever and the flu symptoms from galvalume poisining. It ain't fun and I'm fairly sure it stays with me. What Rich said.

[Hoary]

Evfreek, Thanks for the research into it. It was actually something I thought of as a possiblity from myth Busters. Of course the subject was apples and oranges compared to this, but they created Ancient Eygptian batteries using a ceramic pot and a copper and iron pipe in a liquid of various at home acids ( ie. lemon juice, vinegar etc.). they tested the voltage by hooking their battery to a copper disk and placed it in water and it looked like it caused some corrosian. From there I figured acid can conduct as well as be a source of electricity but would it speed the acid's productivity. Just a thought but you've gone ahead and found this stuff out, which forgive me if I'm wrong, sounds like it makes a safer and beneficial method of degalvinzing metal. I'm glad I could contribute an idea, that's all it was for me, but how excited I am to know it might have produced a positive result. Thank you, but of course I do acknowledge this as being a risky business no matter what you do for safety. I do listen to wisdom when there's more than my eyebrows at stake :-p.