LCD Boards - ENIG Recovery

[hauger]

I've been searching for a while to the following and haven't found an answer yet.

Early days of getting into this hobby (and for me it is a hobby, no profit motive although I'd be happy not to lose money) I made a dumb purchase on Ebay. Yes, judge at your leisure, but it's a mistake already made. I bought a lot of old LCD boards that I now know is almost guaranteed to be ENIG gold.

I've de-populated and cut everything to easily handled "fingers". I have maybe 1.5 lbs of trimmed boards (fingers) now.

I've seen more than a few say not to use AP on these like I would on fingers. Okay, I'll bite. I get that any gold will come off as particulate making recovery difficult, not to mention a huge ratio of toxic copper solution created compared to the gold that's there.

Thing is, no one ever says what to do to recover ENIG, just "don't use AP". I'm hoping no one says reverse electroplating, I don't have the equipment. What about selective leaching? I've never used Cyanide. Would Iodine work? I've never used Iodine either, but if it's easier and more productive than AP, I'm in.

So, anyone have any tips? Thanks.

 

[kernels]

There is no reason why AP wouldn't work, it is just as you state, you create a lot of toxic waste for a small amount of Gold.

Cyanide is tricky for the inexperienced, relatively simple in principle, but getting hold of 'proper' cyanide salts can be difficult (illegal) and then there is significant danger if you stuff up.

I have not had much luck with Iodine, I have a read a mountain of patents, follow them to the letter and still only end up with 10% of the Gold I expected from the very well known material I ran.

The reality is that considering you have only 1.5 lbs, which will yield a tiny amount of Gold, it is probably not worth doing. Much better to start with 1.5 lbs of ram fingers so you end up working with visible amounts of Gold while you learn.

 

[hauger]

That's valid....I have worked on fingers and karat gold so far, been diligent and careful and managed to collect (much to my surprise) pretty close to my expected yields.

Maybe what I'll do is just mix these in with normal fingers. I have about 7 lbs of fingers to process, so maybe throwing these in I can get an extra 0.5 grams or so and chalk it up as lesson learned.

 

[Shark]

AP can be reused as well, giving more use over time. It really depends on how often you will be processing similar items. Mixing them in with your fingers sounds like the best idea. It is how I run mine most of the time.

 

[kernels]

The problem with mixing them in with your good quality plated stuff like fingers is that you still have to etch all the Copper which will saturate your AP that much sooner, but you don't really get the reward for it. Filtering also takes longer because of all the tiny gold particles instead of the nice 'solid' foils.

But as I said, it will work just fine, it's all down to how you value it.