eccobond ct-5047

[AuMINIMayhem]

I've come across a cache of old Eccobond silver epoxy (made by Emmerson cummings) that they just throw away here at work.. jars upon jars of the stuff (pricing is several hundred dollars per jar for a couple of ounces). They toss the stuff the day it expires (gotta love defense contractors!).

I'm wondering if it's worth dipping the whole jar (plastic jars with paper labels) in Nitric and reclaiming the silver values.. the reason I don't want to try and scrape the stuff out is that it's consistency is very strange indeed and there is really no way of scraping it out with any sort of tool that you wouldn't make an absolute mess (and lose values... :shock: )

[img:375:500]http://www.ellsworth.com/imagelibrary/jpegs/100/LargePics/CT-5047-2_PART_A_125_GRAM.jpg[/img]

 

[goldsilverpro]

Try the nitric on a small sample first. You don't know how the nitric will deal with the organics. You might have a big mess. You may have to incinerate first. Here again, prove your process with small samples.

Your company will also have empty containers of this material. Usually, there will be quite a bit of residue left in them.

 

[AuMINIMayhem]

GSP.. yeah I was going to try a teensy bit just to see if it can attack it without creating something volatile.. hard to tell what sort of reactions you can get when you start adding a bunch of "unknown variables". I kept a few jars that were used up, but like you said (I'm assuming you're familiar with this stuff?) the stuff smears quite a bit and there's a lot on the inside of the lids and the sides of the barrels.. not so much enough for "recovery" purposes, but definitely enough to check for volatile reactions, etc. :wink:

 

[scpurdue]

If the epoxy is not cured then you my be able to dissolve it in a solvent like acetone. This may allow you to filter out the silver.

 

[AuMINIMayhem]

unfortunately when discarding they take the remaining hardener and mix it with the resin

I haven't had the time to try a small bit with nitric yet, but it seems promising.

 

[goldsilverpro]

I don't think nitric will work if it is cured. I may be wrong, but all the silver is coated and the acid will first have to eat the epoxy in order to get to the silver. In my experience, epoxies stand up pretty well to many acids. Some will even stand up to concentrated sulfuric, at least for a little while. Of course, there are different types of epoxy. It's worth a try on a small sample. I would try it with full strength nitric first and work backwards. However, if it doesn't work with strong nitric, you know that it won't work with weaker nitric.

It might work with hot concentrated sulfuric (dangerous), but the silver would dissolve. Also, there would be a lot of non-settling carbon in the solution. It would be a mess.

Are there solvents for cured epoxy? They are sold as such but, from what I read, cured cross-linked epoxy is not truly dissolved in solvents - it is only plasticized. You end up with goo.

http://www.google.com/search?q=cured+epoxy+solvent&sourceid=navclient-ff&ie=UTF-8&rlz=1B3GGGL_enUS259US259&aq=t

Maybe you could dip it (freeze it) in liquid nitrogen and then quickly grind it to a powder. Maybe that would liberate the silver so the nitric could get to it. I doubt that it would get it all.

Were it me, I would try to break it up, if possible, and then would try to burn it slowly to at least a light gray ash. There will be nasty smoke. Do a small sample and work your way up. Then, I might use nitric, although I would probably just flux melt it with borax. It's already pure, at that point. Why mess with it? If you use nitric and copper cementation, you will contaminate it.

 

[Sodbuster]

First of all I know next to nothing about chemistry, and I am only speculating when I say this. But I tend to think something like brake fluid would break down epoxies. I know it don't like epoxie paint. Heck it mite even have the ability to remove the solder mask off of a PC board.
Somebody stop me befor i go try this.
Ray

 

[AuMINIMayhem]

Ray.. damnit... somebody stop ME bofore I go try that!!.. :lol:

GSP.. you know what, you may be on to something there... I do have a kiln. I could set it up at a low temperature, prehaps around 6-700f, something like that just to burn off the VOC's, melt any of the platics, etc.. drop it in ice cold distilled water and let thermal shock take care of the rest. then, I could try a spot of nitric with a small sample and hot sulfuric with a small sample and see what works (I'm talking sample sizes of a gram at most with a couple mL's of the different acids..) heck, I MAY even try the brake fluid just for crap and giggles.. :lol: