Goldfinger metals & refinement question

Anarchy618 · Feb 6, 2018

I have been using a soldering gun with much success to remove those lovely gold foils off circuit boards & alike. I've found that if I quickly torch the board to melt solder & slightly separate the foil, you can use a flat tipped soldering gun to essentially scrape off the gold foiled parts quite easily. That being said I've managed to aquire a nice amount of "gold plated foils" from different circuit boards, memory cards, ink cartridges etc. My question is this, since I was able to remove them without needing the assistance of the different acidic methods is there a way I can just use fire to separate the gold from its copper & zinc base? If it was you & you had what I have in the attached pic, what would be YOUR next step with this 13.8 grams of foils?

patnor1011 · Feb 6, 2018

You sadly can't use just fire. Chemical method is needed. Also for future, there is no point to scrape foils off the board as there is simply very little value to warrant such time and energy waste.
While they do look nice there is very little gold on them. There may be about half a gram of gold (or less) in your 13 grams of foils.

kernels · Feb 6, 2018

Yep, Patnor has beaten me to it, there is far less Gold there than you think, the Copper layer is just so much thicker than the Gold. I did refine some foils once that were removed in this way, I think I still have a note about the yield in my lab book at home somewhere, will post the yield for you when I get home tonight, which will tell you exactly how much Gold is in there. But rough estimate is certainly less than 1g.

goldsilverpro · Feb 7, 2018

The copper on that stuff is about 22 to 44 times thicker than the gold, depending on whether the copper is the 1 oz or 2 oz per sq.ft. type.

Joko sulistyo · Feb 8, 2018

If I have "gold plated foils" like that,I will melt them all and then refining the button using acid method.
Scrapping gold foils using solder gun is not efficient.That will spending time.

Sent from my ASUS_Z008D using Tapatalk

niks neims · Feb 8, 2018

Joko sulistyo said:
If I have "gold plated foils" like that,I will melt them all and then refining the button using acid method.
Scrapping gold foils using solder gun is not efficient.That will spending time.

Sent from my ASUS_Z008D using Tapatalk

Why would you melt it? Button takes ages to dissolve, cornflake or shot is better, because then there is a larger surface area but still not as large as being in the foil form.... They should go in to acid as is - in foil form. First either AP or nitric to dissolve away the copper, then AR. That being said, same process would apply to simple, cut fingers, so i really dont see the point of removing foils first in the way that OP did....

-Artūrs

rickbb · Feb 8, 2018

Save it all until you have pounds of them, then use the AP/HCL bleach process. Lowest cost method and it works just fine, at least for the home/hobbyist refiner.

Unless you have tons of time on your hands and you're just bored, don't bother with mechanical removal of foils. It will take literally forever to accumulate enough foils to bother with.

kernels · Feb 9, 2018

OK, dug up my old notebook, "Soldering Iron Removed Foils" I processed 25.58g and recovered 0.53g, giving a yield of 20.72g/kg.

So Anarchy, you can weigh up what you've got vs the time taken to collect them.

FrugalRefiner · Feb 9, 2018

Thanks for sharing that data kernels! I had added an experiment like this to my "to do" list. Now I can cross it off. 8)

Dave

goldsilverpro · Feb 9, 2018

Lot of work, Anarchy, for 10 bucks. Definitely not the way to do it.

glorycloud · Feb 11, 2018

I hope that, for the sake of your health, you are using a soldering gun
to remove the foils in a well ventilated area. I de-solder some chips
off of boards and I know that the fumes can be bad. Especially when
the chip is well soldered on the board and it doesn't want to "let go". 8)

Anarchy618 · Feb 17, 2018

I have absolutely learned several very valuable lessons from each & every persons responses. One that sticks out most is just howwwww much I overlooked the amount of recovery/yield & foolishly but exitedly assumed there was much more gold than there really is. You can only truly get a general idea to understand or try predicting how much (or little, in my case lol) of your beautiful brown powder amounts that'lll end up accumilating on the bottom of that beaker after your SMB drop or copper buss bar drop method (where each method are 1 of 2 separate ways to precipitate gold from auric chloride solution). It certainly does take alot more e waste than I thought to obtain decent yeilds. But that only makes me more determined. I should forewarn anyone thinking about learning chemistry that it's more addictive & more fun the more u understand & learn than any recreational drug you've ever experimented <-- (and yes that pun was intended! Lol) with or tried. It's amazingly fun & obviously way more lucrative than giving money for a different drug next to literally paying yourself by getting hooked on this one, chemistry. I'm very gracious for the warm welcome & friendly advice on the forum to every single of my posts that never go unanswered. I am having such a fun time during my learning/experimenting experience thanks to being able to have acess to the great intelligent people on this forum (and also Moosescrappers videos on YouTube are awesome for ANY newbie) I had to give this shout out so maybe it'll make other great people want to be a part of this free community of willing educators so eager to answer a strangers dilemma with such clarity. Thanks & god bless you all.

blackwolf365 · Jul 21, 2019

to bad this is such a time comsuming way to get the foils off the board. might be an interesting reaseach and experimenting project to find a way to make it less of a time comsuming way.

Jochris · Jul 24, 2019

Fairly new to the gold refining world, and as i know and understand most of the processes used to seperate and refine i also enjoy the knowledge learning aspect as well i dont just want to use the process but also understand how and why it works. That being said my question is when using hcl/bleach to dissovle foils how come when omg... Nevermind just answered my own question sometimes we need to slow ourselves down and take a step back and approach the issue a new way to find our answers.

blackwolf365 · Jan 20, 2020

you know guys, there is an up side to using a soldering iron to remove the foils. i'm just putting a personal thought out here, of course. yes it involves time and effort. yet that time and effort increases with the amount of chips to be scraped. i'm not disputing those two facts. but think of it this way: how much could manually scraping the foils off save in chemical costs? furthermore, if you have a vast quantity of chips to scrape, and you don't mind doing small amounts at a time, scraping the foils off can save a great deal of money in chemical costs. personally, i wouldn't mind taking the time to scrape the foils. it would give me something to keep occupied, but that's just me.

g_axelsson · Jan 20, 2020

Difference in chemical cost between peeling the foils off the boards compared to cutting off the edge of the board...

It's negligible, assuming that you use the same chemicals to remove the copper from the foils regardless if the foils are still on a piece of plastic or not. Some boards have internal copper layers so there are a slight increase in how much copper is dissolved, but the inner layers are attacked a lot slower than the outer layers, so if you are concerned with the chemical cost then you just need to watch carefully and remove any fingers where the foils have dropped off.

Actually, there could be even less chemical cost, sometimes there are still copper left on the board when the foils drops off. That's especially true for thin plating where the copper is attacked through the plating and not only from the sides.

Once upon a time I peeled the foils off boards, using a razor blade. But since I became a member of this forum I've never done that again and I'm not missing it. Now I use a short flat nosed pliers and just break off the fingers in a couple of seconds. As a side effect the gold fingers becomes a bit twisted so it doesn't pack well and that lets the copper chloride access the foils better.
If I have many cards to cut I put a vice with the gap horizontal and adjust the gap just a bit wider than the thickness of the board. I then slide the board into the gap and press down with my hand. It only takes seconds per board to break off the fingers.

I usually have a jar sitting with copper chloride and I drop fingers into it at the end of the day and I remove any cleaned fingers. Slowly over time the bottom is covered in foils. When I got enough I harvest the foils and refine it.

Göran

blackwolf365 · Jan 21, 2020

i guess it depends on how much time you want to spend on it personally, right now, i have a lot of time on my hands, so manually scraping them off the boards don't seem to inconvenient to me. but thats me. some might agree, some might disagree, but thats just how life works.

Shark · Jan 21, 2020

I agree with Göran in that the time saved could be used to look for more materials. Sourcing materials is often the biggest hold up for the small refiner just getting started out. If you save five minutes you now have enough time to make a phone call to a potential source.

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